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Sample records for agronomic significance maize

  1. Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat.

    PubMed

    Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

    2015-01-01

    Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha(-1)), and economic benefit (3,408 USD ha(-1)). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating

  2. Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat

    PubMed Central

    Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

    2015-01-01

    Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha-1), and economic benefit (3,408 USD ha-1). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating

  3. Descriptive statistics and correlation analysis of agronomic traits in a maize recombinant inbred line population.

    PubMed

    Zhang, H M; Hui, G Q; Luo, Q; Sun, Y; Liu, X H

    2014-01-01

    Maize (Zea mays L.) is one of the most important crops in the world. In this study, 13 agronomic traits of a recombinant inbred line population that was derived from the cross between Mo17 and Huangzao4 were investigated in maize: ear diameter, ear length, ear axis diameter, ear weight, plant height, ear height, days to pollen shed (DPS), days to silking (DS), the interval between DPS and DS, 100-kernel weight, kernel test weight, ear kernel weight, and kernel rate. Furthermore, the descriptive statistics and correlation analysis of the 13 traits were performed using the SPSS 11.5 software. The results providing the phenotypic data here are needed for the quantitative trait locus mapping of these agronomic traits. PMID:24535873

  4. Genome wide association study for drought, aflatoxin resistance, and important agronomic traits of maize hybrids in the sub-tropics.

    PubMed

    Farfan, Ivan D Barrero; De La Fuente, Gerald N; Murray, Seth C; Isakeit, Thomas; Huang, Pei-Cheng; Warburton, Marilyn; Williams, Paul; Windham, Gary L; Kolomiets, Mike

    2015-01-01

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world and this is where most maize breeding is focused. Important but lower yielding maize growing regions such as the sub-tropics experience unique challenges, the greatest of which are drought stress and aflatoxin contamination. Here we used a diversity panel consisting of 346 maize inbred lines originating in temperate, sub-tropical and tropical areas testcrossed to stiff-stalk line Tx714 to investigate these traits. Testcross hybrids were evaluated under irrigated and non-irrigated trials for yield, plant height, ear height, days to anthesis, days to silking and other agronomic traits. Irrigated trials were also inoculated with Aspergillus flavus and evaluated for aflatoxin content. Diverse maize testcrosses out-yielded commercial checks in most trials, which indicated the potential for genetic diversity to improve sub-tropical breeding programs. To identify genomic regions associated with yield, aflatoxin resistance and other important agronomic traits, a genome wide association analysis was performed. Using 60,000 SNPs, this study found 10 quantitative trait variants for grain yield, plant and ear height, and flowering time after stringent multiple test corrections, and after fitting different models. Three of these variants explained 5-10% of the variation in grain yield under both water conditions. Multiple identified SNPs co-localized with previously reported QTL, which narrows the possible location of causal polymorphisms. Novel significant SNPs were also identified. This study demonstrated the potential to use genome wide association studies to identify major variants of quantitative and complex traits such as yield under drought that are still segregating between elite inbred lines.

  5. Genome Wide Association Study for Drought, Aflatoxin Resistance, and Important Agronomic Traits of Maize Hybrids in the Sub-Tropics

    PubMed Central

    Farfan, Ivan D. Barrero; De La Fuente, Gerald N.; Murray, Seth C.; Isakeit, Thomas; Huang, Pei-Cheng; Warburton, Marilyn; Williams, Paul; Windham, Gary L.; Kolomiets, Mike

    2015-01-01

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world and this is where most maize breeding is focused. Important but lower yielding maize growing regions such as the sub-tropics experience unique challenges, the greatest of which are drought stress and aflatoxin contamination. Here we used a diversity panel consisting of 346 maize inbred lines originating in temperate, sub-tropical and tropical areas testcrossed to stiff-stalk line Tx714 to investigate these traits. Testcross hybrids were evaluated under irrigated and non-irrigated trials for yield, plant height, ear height, days to anthesis, days to silking and other agronomic traits. Irrigated trials were also inoculated with Aspergillus flavus and evaluated for aflatoxin content. Diverse maize testcrosses out-yielded commercial checks in most trials, which indicated the potential for genetic diversity to improve sub-tropical breeding programs. To identify genomic regions associated with yield, aflatoxin resistance and other important agronomic traits, a genome wide association analysis was performed. Using 60,000 SNPs, this study found 10 quantitative trait variants for grain yield, plant and ear height, and flowering time after stringent multiple test corrections, and after fitting different models. Three of these variants explained 5–10% of the variation in grain yield under both water conditions. Multiple identified SNPs co-localized with previously reported QTL, which narrows the possible location of causal polymorphisms. Novel significant SNPs were also identified. This study demonstrated the potential to use genome wide association studies to identify major variants of quantitative and complex traits such as yield under drought that are still segregating between elite inbred lines. PMID:25714370

  6. Genome wide association study for drought, aflatoxin resistance, and important agronomic traits of maize hybrids in the sub-tropics.

    PubMed

    Farfan, Ivan D Barrero; De La Fuente, Gerald N; Murray, Seth C; Isakeit, Thomas; Huang, Pei-Cheng; Warburton, Marilyn; Williams, Paul; Windham, Gary L; Kolomiets, Mike

    2015-01-01

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world and this is where most maize breeding is focused. Important but lower yielding maize growing regions such as the sub-tropics experience unique challenges, the greatest of which are drought stress and aflatoxin contamination. Here we used a diversity panel consisting of 346 maize inbred lines originating in temperate, sub-tropical and tropical areas testcrossed to stiff-stalk line Tx714 to investigate these traits. Testcross hybrids were evaluated under irrigated and non-irrigated trials for yield, plant height, ear height, days to anthesis, days to silking and other agronomic traits. Irrigated trials were also inoculated with Aspergillus flavus and evaluated for aflatoxin content. Diverse maize testcrosses out-yielded commercial checks in most trials, which indicated the potential for genetic diversity to improve sub-tropical breeding programs. To identify genomic regions associated with yield, aflatoxin resistance and other important agronomic traits, a genome wide association analysis was performed. Using 60,000 SNPs, this study found 10 quantitative trait variants for grain yield, plant and ear height, and flowering time after stringent multiple test corrections, and after fitting different models. Three of these variants explained 5-10% of the variation in grain yield under both water conditions. Multiple identified SNPs co-localized with previously reported QTL, which narrows the possible location of causal polymorphisms. Novel significant SNPs were also identified. This study demonstrated the potential to use genome wide association studies to identify major variants of quantitative and complex traits such as yield under drought that are still segregating between elite inbred lines. PMID:25714370

  7. Determining the optimal nitrogen rate for summer maize in China by integrating agronomic, economic, and environmental aspects

    NASA Astrophysics Data System (ADS)

    Wang, G. L.; Ye, Y. L.; Chen, X. P.; Cui, Z. L.

    2014-06-01

    The concept of high yield with a goal of minimum environmental cost has become widely accepted. However, the trade-offs and complex linkages among agronomic, economic, and environmental factors are not yet well understood. In this study, reactive nitrogen (Nr) losses were estimated using an empirical model, and an economic indicator and an evaluation model were used to account for the environmental costs of N fertilizer production and use. The minimum N rate to achieve the maximum yield benefit (agronomically optimal N rate), maximum economic benefit (economically optimal N rate: economic benefit was defined as yield benefit minus N fertilizer cost), and maximum net benefit (ecologically optimal N rate: net benefit was defined as yield benefit minus N fertilizer and environmental costs) were estimated based on 91 on-farm experiment sites with five N levels for summer maize production on the North China Plain. Across all experimental sites, the agronomically, economically, and ecologically optimal N rates (Nagr, Neco, and Necl, respectively) averaged 289, 237, and 171 kg N ha-1, respectively. Necl management increased net benefit by 53% with a 46% decrease in total environmental costs, and a 51% decrease in Nr loss intensity from N fertilizer use (47, 65, and 38% for N2O emission, N leaching, and NH3 volatilization, respectively) and maintained grain yield, compared with Nagr management. Compared with Neco management, Necl increased net benefit by 12%, with a 31% decrease in total environmental costs and a 33% decrease in Nr loss intensity from N fertilizer use, and maintained economic benefit and grain yield. No differences in Necl were observed between soil types or years, but significant variation among counties was revealed. Necl increased with the increase in N-derived yield with an R2 of 0.83. In conclusion, Necl was primarily affected by N-derived yield and could enhance profitability as well as reduce Nr losses associated with the maize grain yield.

  8. Determining the optimal nitrogen rate for summer maize in China by integrating agronomic, economic, and environmental aspects

    NASA Astrophysics Data System (ADS)

    Wang, G. L.; Ye, Y. L.; Chen, X. P.; Cui, Z. L.

    2014-02-01

    The concept of high yield with a goal of minimum environmental cost has become widely accepted. However, the trade-offs and complex linkages among agronomic, economic, and environmental factors are not yet well understood. In this study, reactive nitrogen (Nr) losses were estimated using an empirical model, and an economic indicator and an evaluation model were used to account for the environmental costs of different Nr losses after N fertilizer application. The minimum N rate to achieve the maximum yield benefit (agronomically optimal N rate), maximum economic benefit (economically optimal N rate: economic benefit was defined as yield benefit minus N fertilizer cost), and maximum net benefit (ecologically optimal N rate: net benefit was defined as yield benefit minus N fertilizer and environmental costs) were estimated based on 91 on-farm experiment sites with five N levels for summer maize production on the North China Plain. Across all experimental sites, the agronomically, economically, and ecologically optimal N rates (Nagr, Neco, and Necl, respectively) averaged 289, 237, and 186 kg N ha-1, respectively. Necl management increased net benefit by 31% with a 45% decrease in Nr loss intensity (44%, 60%, and 33% for N2O emission, N leaching, and NH3 volatilization, respectively) and maintained grain yield, compared to Nagr management. Compared to Neco management, Necl increased net benefit by 6%, with a 27% decrease in Nr loss intensity, and maintained economic benefit and grain yield. No differences in Necl were observed between soil types or years, but significant variation among counties was revealed. Necl increased with the increase in N-derived yield with an R2 of 0.80. In conclusion, Necl was primarily affected by N-derived yield and could enhance profitability as well as reduce Nr losses associated with the maize grain yield.

  9. Genetic diversity, population structure, and association mapping of agronomic traits in waxy and normal maize inbred lines.

    PubMed

    Sa, K J; Park, J Y; Choi, S H; Kim, B W; Park, K J; Lee, J K

    2015-01-01

    Understanding genetic diversity, population structure, and linkage disequilibrium is a prerequisite for the association mapping of complex traits in a target population. In this study, the genetic diversity and population structure of 40 waxy and 40 normal inbred maize lines were investigated using 10 morphological traits and 200 simple sequence repeat (SSR) markers. Based on a population structure analysis, the 80 maize inbred lines were divided into three groups: I, II, and admixed. Significant marker-trait associations were identified between the markers and the 10 morphological traits, which were studied according to the model used to confirm the association. Using a general linear model, the lowest R(2) value (9.03) was detected in umc1139, which was associated with ear number, and the highest (43.97) was in umc1858, which was associated with plant height. Using a mixed linear model, the lowest R(2) value (18.74) was in umc1279, which was associated with ear weight; the highest (27.66) was in umc1858, which was associated with 100-kernel weight. The SSR markers identified in the present study may serve as useful molecular markers for selecting important yield and agronomic traits. These results will be useful for marker-assisted selection in maize breeding programs, to help breeders choose parental lines and markers for crosses.

  10. Cereal grass pulvini: agronomically significant models for studying gravitropism signaling and tissue polarity.

    PubMed

    Clore, Amy M

    2013-01-01

    Cereal grass pulvini have emerged as model systems that are not only valuable for the study of gravitropism, but are also of agricultural and economic significance. The pulvini are regions of tissue that are apical to each node and collectively return a reoriented stem to a more vertical position. They have proven to be useful for the study of gravisensing and response and are also providing clues about the establishment of polarity across tissues. This review will first highlight the agronomic significance of these stem regions and their benefits for use as model systems and provide a brief historical overview. A detailed discussion of the literature focusing on cell signaling and early changes in gene expression will follow, culminating in a temporal framework outlining events in the signaling and early growth phases of gravitropism in this tissue. Changes in cell wall composition and gene expression that occur well into the growth phase will be touched upon briefly. Finally, some ongoing research involving both maize and wheat pulvini will be introduced along with prospects for future investigations. PMID:23125431

  11. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding.

    PubMed

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-08-20

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects.

  12. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding.

    PubMed

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-08-01

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects. PMID:26308050

  13. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding

    PubMed Central

    Santiago, Rogelio; Cao, Ana; Butrón, Ana

    2015-01-01

    Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects. PMID:26308050

  14. Agronomic application of olive mill wastewater: Effects on maize production and soil properties.

    PubMed

    Belaqziz, Majdouline; El-Abbassi, Abdelilah; Lakhal, El Khadir; Agrafioti, Evita; Galanakis, Charis M

    2016-04-15

    This study investigates the effect of direct amendment of olive mill wastewater (OMW) on the fertility of soil, described as poor in the area of Marrakech (semi-arid region) in Morocco. The treated plots were amended with untreated OMW generated by a traditional extraction process at the amount of 10 L/m(2)/year during two consecutive years. Results of these two years treatments with crude OMW at relatively high dose reveal an important increase in soil physicochemical characteristics, namely electric conductivity (EC), Na(+,) K(+), phosphorus, nitrogen, organic matter and soluble phenolic compounds. EC of treated soil was enhanced from 0.34 to 2.91 mS/cm as compared to the control soil. After spreading OMW in soil, the amounts of its nutritive elements increased by 81% for nitrogen, 66% for phosphorus and 88% for potassium. The accumulation of phenolic compounds and the increase of total peroxidase activity in plants provide evidence of their protective role against the physiological stress induced by OMW. However, this enrichment in mineral and nutritive elements decreased three months after OMW application, revealing OMW biodegradation in the studied calcareous soil. In parallel, an increase in the contents of the soluble phenolic compounds on the upper layer of soil was denoted and maize plants growth was efficiently raised. Significant amelioration was obtained notably in terms of fresh and dry weight of leaves, leaves area, spikes fresh and dry weight, 100 seeds weight and straw yield (37, 54, 27, 24, 14 and 9% respectively). Along with the correct choice of convenient soils notably calcareous ones and tolerant crops such as maize, this method could constitute an efficient approach for avoiding problems attributed to the uncontrolled disposal of these effluents and an effective strategy to regenerate degraded soils and represents an economical alternative that provides a local fertilizer.

  15. Agronomic application of olive mill wastewater: Effects on maize production and soil properties.

    PubMed

    Belaqziz, Majdouline; El-Abbassi, Abdelilah; Lakhal, El Khadir; Agrafioti, Evita; Galanakis, Charis M

    2016-04-15

    This study investigates the effect of direct amendment of olive mill wastewater (OMW) on the fertility of soil, described as poor in the area of Marrakech (semi-arid region) in Morocco. The treated plots were amended with untreated OMW generated by a traditional extraction process at the amount of 10 L/m(2)/year during two consecutive years. Results of these two years treatments with crude OMW at relatively high dose reveal an important increase in soil physicochemical characteristics, namely electric conductivity (EC), Na(+,) K(+), phosphorus, nitrogen, organic matter and soluble phenolic compounds. EC of treated soil was enhanced from 0.34 to 2.91 mS/cm as compared to the control soil. After spreading OMW in soil, the amounts of its nutritive elements increased by 81% for nitrogen, 66% for phosphorus and 88% for potassium. The accumulation of phenolic compounds and the increase of total peroxidase activity in plants provide evidence of their protective role against the physiological stress induced by OMW. However, this enrichment in mineral and nutritive elements decreased three months after OMW application, revealing OMW biodegradation in the studied calcareous soil. In parallel, an increase in the contents of the soluble phenolic compounds on the upper layer of soil was denoted and maize plants growth was efficiently raised. Significant amelioration was obtained notably in terms of fresh and dry weight of leaves, leaves area, spikes fresh and dry weight, 100 seeds weight and straw yield (37, 54, 27, 24, 14 and 9% respectively). Along with the correct choice of convenient soils notably calcareous ones and tolerant crops such as maize, this method could constitute an efficient approach for avoiding problems attributed to the uncontrolled disposal of these effluents and an effective strategy to regenerate degraded soils and represents an economical alternative that provides a local fertilizer. PMID:26899012

  16. Agronomic and kernel compositional traits of blue maize landraces from the southwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple races of maize have been cultivated for centuries in the southwestern USA and northern Mexico. These landraces, used primarily for human food consumption, display considerable genetic variation for traits such as kernel color and texture. Traditional cultivation of these landraces has decli...

  17. QTL Mapping of Agronomic Waterlogging Tolerance Using Recombinant Inbred Lines Derived from Tropical Maize (Zea mays L) Germplasm

    PubMed Central

    Zaidi, Pervez Haider; Rashid, Zerka; Vinayan, Madhumal Thayil; Almeida, Gustavo Dias; Phagna, Ramesh Kumar; Babu, Raman

    2015-01-01

    Waterlogging is an important abiotic stress constraint that causes significant yield losses in maize grown throughout south and south-east Asia due to erratic rainfall patterns. The most economic option to offset the damage caused by waterlogging is to genetically incorporate tolerance in cultivars that are grown widely in the target agro-ecologies. We assessed the genetic variation in a population of recombinant inbred lines (RILs) derived from crossing a waterlogging tolerant line (CAWL-46-3-1) to an elite but sensitive line (CML311-2-1-3) and observed significant range of variation for grain yield (GY) under waterlogging stress along with a number of other secondary traits such as brace roots (BR), chlorophyll content (SPAD), % stem and root lodging (S&RL) among the RILs. Significant positive correlation of GY with BR and SPAD and negative correlation with S&RL indicated the potential use of these secondary traits in selection indices under waterlogged conditions. RILs were genotyped with 331 polymorphic single nucleotide polymorphism (SNP) markers using KASP (Kompetitive Allele Specific PCR) Platform. QTL mapping revealed five QTL on chromosomes 1, 3, 5, 7 and 10, which together explained approximately 30% of phenotypic variance for GY based on evaluation of RIL families under waterlogged conditions, with effects ranging from 520 to 640 kg/ha for individual genomic regions. 13 QTL were identified for various secondary traits associated with waterlogging tolerance, each individually explaining from 3 to 14% of phenotypic variance. Of the 22 candidate genes with known functional domains identified within the physical intervals delimited by the flanking markers of the QTL influencing GY and other secondary traits, six have previously been demonstrated to be associated with anaerobic responses in either maize or other model species. A pair of flanking SNP markers has been identified for each of the QTL and high throughput marker assays were developed to facilitate

  18. Whole genome association study for drought, aflatoxin resistance, and important agronomic traits in maize in a sub-tropical environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world, where most maize breeding is focused. Important but lower yielding maize growing regions, such as the sub-tropics, experience unique challenges the greatest of which are drought stress and aflatoxin conta...

  19. QTLs for agronomic and cell wall traits in a maize RIL progeny derived from a cross between an old Minnesota13 line and a modern Iodent line.

    PubMed

    Barrière, Yves; Méchin, Valérie; Lefevre, Bruno; Maltese, Stéphane

    2012-08-01

    In order to contribute to the inventory of genomic areas involved in maize cell wall lignification and degradability, QTL analyses were investigated in a RIL progeny between an old Minnesota13 dent line (WM13) and a modern Iodent line (RIo). Significant variation for agronomic- and cell wall-related traits was observed for the RIL per se (plants without ears) and topcross (whole plants) experiments after crossing with both old (Ia153) and modern tester (RFl) lines. Three QTLs for stover (plant without ear) yield were observed in per se experiments, with alleles increasing yield originating from RIo in two genomic locations with the highest effects. However, no QTL for whole plant yield was detected in topcross experiments, despite the fact that two QTLs for starch content were shown with increasing alleles originating from the modern RIo line. Fifteen lignin QTLs were shown, including a QTL for Klason lignins in per se experiments, located in bin 2.04, which explained 43 % of the observed genetic variation. Thirteen QTLs for p-hydroxycinnamic acid contents and nine QTLs related to the monomeric composition of lignin were shown in per se experiments, with syringaldehyde and diferulate QTLs explaining nearly 25 % of trait variations. Nine and seven QTLs for cell wall digestibility were mapped in per se and topcross experiments, respectively. Five of the per se QTLs explained more than 15 % of the variation, up to nearly 25 %. QTL positions in bins 2.06, 5.04, 5.08 and 8.02 for ADL/NDF, IVNDFD, lignin structure and/or p-hydroxycinnamic acid contents have not been previously shown and were thus first identified in the RIo × WM13 progeny. Based on QTL colocalizations, differences in cell wall degradability between RIo and WM13 were less often related to acid detergent lignin (ADL) content than in previous RIL investigations. QTL colocalizations then highlighted the probable importance of ferulate cross linkages in variation for cell wall digestibility. No

  20. Maize growing duration was prolonged across China in the past three decades under the combined effects of temperature, agronomic management, and cultivar shift.

    PubMed

    Tao, Fulu; Zhang, Shuai; Zhang, Zhao; Rötter, Reimund P

    2014-12-01

    Maize phenology observations at 112 national agro-meteorological experiment stations across China spanning the years 1981-2009 were used to investigate the spatiotemporal changes of maize phenology, as well as the relations to temperature change and cultivar shift. The greater scope of the dataset allows us to estimate the effects of temperature change and cultivar shift on maize phenology more precisely. We found that maize sowing date advanced significantly at 26.0% of stations mainly for spring maize in northwestern, southwestern and northeastern China, although delayed significantly at 8.0% of stations mainly in northeastern China and the North China Plain (NCP). Maize maturity date delayed significantly at 36.6% of stations mainly in the northeastern China and the NCP. As a result, duration of maize whole growing period (GPw) was prolonged significantly at 41.1% of stations, although mean temperature (Tmean) during GPw increased at 72.3% of stations, significantly at 19.6% of stations, and Tmean was negatively correlated with the duration of GPw at 92.9% of stations and significantly at 42.9% of stations. Once disentangling the effects of temperature change and cultivar shift with an approach based on accumulated thermal development unit, we found that increase in temperature advanced heading date and maturity date and reduced the duration of GPw at 81.3%, 82.1% and 83.9% of stations on average by 3.2, 6.0 and 3.5 days/decade, respectively. By contrast, cultivar shift delayed heading date and maturity date and prolonged the duration of GPw at 75.0%, 94.6% and 92.9% of stations on average by 1.5, 6.5 and 6.5 days/decade, respectively. Our results suggest that maize production is adapting to ongoing climate change by shift of sowing date and adoption of cultivars with longer growing period. The spatiotemporal changes of maize phenology presented here can further guide the development of adaptation options for maize production in near future.

  1. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize.

    PubMed

    Asters, Matthew C; Williams, W Paul; Perkins, Andy D; Mylroie, J Erik; Windham, Gary L; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimized a pipeline of analysis tools chosen from various programs to provide rigorous statistical analysis and state of the art data visualization. A network-based method was also explored to construct the empirical gene expression relational structures. Maize genes at the centers in the network were considered as important candidate genes for maize DNA marker studies. The methods in this research can be used to analyze large RT-qPCR datasets and establish complex empirical gene relational structures across multiple experimental conditions. PMID:24770700

  2. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize

    PubMed Central

    Asters, Matthew C.; Williams, W. Paul; Perkins, Andy D.; Mylroie, J. Erik; Windham, Gary L.; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimized a pipeline of analysis tools chosen from various programs to provide rigorous statistical analysis and state of the art data visualization. A network-based method was also explored to construct the empirical gene expression relational structures. Maize genes at the centers in the network were considered as important candidate genes for maize DNA marker studies. The methods in this research can be used to analyze large RT-qPCR datasets and establish complex empirical gene relational structures across multiple experimental conditions. PMID:24770700

  3. Genome wide association studies using a new nonparametric model reveal the genetic architecture of 17 agronomic traits in an enlarged maize association panel.

    PubMed

    Yang, Ning; Lu, Yanli; Yang, Xiaohong; Huang, Juan; Zhou, Yang; Ali, Farhan; Wen, Weiwei; Liu, Jie; Li, Jiansheng; Yan, Jianbing

    2014-09-01

    Association mapping is a powerful approach for dissecting the genetic architecture of complex quantitative traits using high-density SNP markers in maize. Here, we expanded our association panel size from 368 to 513 inbred lines with 0.5 million high quality SNPs using a two-step data-imputation method which combines identity by descent (IBD) based projection and k-nearest neighbor (KNN) algorithm. Genome-wide association studies (GWAS) were carried out for 17 agronomic traits with a panel of 513 inbred lines applying both mixed linear model (MLM) and a new method, the Anderson-Darling (A-D) test. Ten loci for five traits were identified using the MLM method at the Bonferroni-corrected threshold -log10 (P) >5.74 (α=1). Many loci ranging from one to 34 loci (107 loci for plant height) were identified for 17 traits using the A-D test at the Bonferroni-corrected threshold -log10 (P) >7.05 (α=0.05) using 556809 SNPs. Many known loci and new candidate loci were only observed by the A-D test, a few of which were also detected in independent linkage analysis. This study indicates that combining IBD based projection and KNN algorithm is an efficient imputation method for inferring large missing genotype segments. In addition, we showed that the A-D test is a useful complement for GWAS analysis of complex quantitative traits. Especially for traits with abnormal phenotype distribution, controlled by moderate effect loci or rare variations, the A-D test balances false positives and statistical power. The candidate SNPs and associated genes also provide a rich resource for maize genetics and breeding.

  4. Agronomic Weeds.

    ERIC Educational Resources Information Center

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University examines agronomic weed problems and control. Contents include a listing of the characteristics of weeds, a section on herbicides, and a section on the important weeds of agronomic crops in Pennsylvania. The herbicide section discusses systemic herbicides, contact…

  5. The Genetic Basis of Heterosis: Multiparental Quantitative Trait Loci Mapping Reveals Contrasted Levels of Apparent Overdominance Among Traits of Agronomical Interest in Maize (Zea mays L.)

    PubMed Central

    Larièpe, A.; Mangin, B.; Jasson, S.; Combes, V.; Dumas, F.; Jamin, P.; Lariagon, C.; Jolivot, D.; Madur, D.; Fiévet, J.; Gallais, A.; Dubreuil, P.; Charcosset, A.; Moreau, L.

    2012-01-01

    Understanding the genetic bases underlying heterosis is a major issue in maize (Zea mays L.). We extended the North Carolina design III (NCIII) by using three populations of recombinant inbred lines derived from three parental lines belonging to different heterotic pools, crossed with each parental line to obtain nine families of hybrids. A total of 1253 hybrids were evaluated for grain moisture, silking date, plant height, and grain yield. Quantitative trait loci (QTL) mapping was carried out on the six families obtained from crosses to parental lines following the “classical” NCIII method and with a multiparental connected model on the global design, adding the three families obtained from crosses to the nonparental line. Results of the QTL detection highlighted that most of the QTL detected for grain yield displayed apparent overdominance effects and limited differences between heterozygous genotypes, whereas for grain moisture predominance of additive effects was observed. For plant height and silking date results were intermediate. Except for grain yield, most of the QTL identified showed significant additive-by-additive epistatic interactions. High correlation observed between heterosis and the heterozygosity of hybrids at markers confirms the complex genetic basis and the role of dominance in heterosis. An important proportion of QTL detected were located close to the centromeres. We hypothesized that the lower recombination in these regions favors the detection of (i) linked QTL in repulsion phase, leading to apparent overdominance for heterotic traits and (ii) linked QTL in coupling phase, reinforcing apparent additive effects of linked QTL for the other traits. PMID:22135356

  6. Genetic Diversity and Molecular Evolution of Chinese Waxy Maize Germplasm

    PubMed Central

    Zheng, Hongjian; Wang, Hui; Yang, Hua; Wu, Jinhong; Shi, Biao; Cai, Run; Xu, Yunbi; Wu, Aizhong; Luo, Lijun

    2013-01-01

    Waxy maize (Zea mays L. var. certaina Kulesh), with many excellent characters in terms of starch composition and economic value, has grown in China for a long history and its production has increased dramatically in recent decades. However, the evolution and origin of waxy maize still remains unclear. We studied the genetic diversity of Chinese waxy maize including typical landraces and inbred lines by SSR analysis and the results showed a wide genetic diversity in the Chinese waxy maize germplasm. We analyzed the origin and evolution of waxy maize by sequencing 108 samples, and downloading 52 sequences from GenBank for the waxy locus in a number of accessions from genus Zea. A sharp reduction of nucleotide diversity and significant neutrality tests (Tajima’s D and Fu and Li’s F*) were observed at the waxy locus in Chinese waxy maize but not in nonglutinous maize. Phylogenetic analysis indicated that Chinese waxy maize originated from the cultivated flint maize and most of the modern waxy maize inbred lines showed a distinct independent origin and evolution process compared with the germplasm from Southwest China. The results indicated that an agronomic trait can be quickly improved to meet production demand by selection. PMID:23818949

  7. Reinventing MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

  8. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis.

    PubMed

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-11-20

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

  9. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

    PubMed Central

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-01-01

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge. PMID:26586114

  10. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-11-01

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

  11. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis.

    PubMed

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-01-01

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge. PMID:26586114

  12. Proteomic analysis of seedling roots of two maize inbred lines that differ significantly in the salt stress response.

    PubMed

    Cui, Dezhou; Wu, Dandan; Liu, Jie; Li, Detao; Xu, Chunyan; Li, Song; Li, Peng; Zhang, Hua; Liu, Xu; Jiang, Chuan; Wang, Liwen; Chen, Tingting; Chen, Huabang; Zhao, Li

    2015-01-01

    Salinity is a major abiotic stress that limits plant productivity and quality throughout the world. Roots are the sites of salt uptake. To better understand salt stress responses in maize, we performed a comparative proteomic analysis of seedling roots from the salt-tolerant genotype F63 and the salt-sensitive genotype F35 under 160 mM NaCl treatment for 2 days. Under salinity conditions, the shoot fresh weight and relative water content were significantly higher in F63 than in F35, while the osmotic potential was significantly lower and the reduction of the K+/Na+ ratio was significantly less pronounced in F63 than in F35. Using an iTRAQ approach, twenty-eight proteins showed more than 2.0- fold changes in abundance and were regarded as salt-responsive proteins. Among them, twenty-two were specifically regulated in F63 but remained constant in F35. These proteins were mainly involved in signal processing, water conservation, protein synthesis and biotic cross-tolerance, and could be the major contributors to the tolerant genotype of F63. Functional analysis of a salt-responsive protein was performed in yeast as a case study to confirm the salt-related functions of detected proteins. Taken together, the results of this study may be helpful for further elucidating salt tolerance mechanisms in maize.

  13. Proteomic Analysis of Seedling Roots of Two Maize Inbred Lines That Differ Significantly in the Salt Stress Response

    PubMed Central

    Cui, Dezhou; Wu, Dandan; Liu, Jie; Li, Detao; Xu, Chunyan; Li, Song; Li, Peng; Zhang, Hua; Liu, Xu; Jiang, Chuan; Wang, Liwen; Chen, Tingting; Chen, Huabang; Zhao, Li

    2015-01-01

    Salinity is a major abiotic stress that limits plant productivity and quality throughout the world. Roots are the sites of salt uptake. To better understand salt stress responses in maize, we performed a comparative proteomic analysis of seedling roots from the salt-tolerant genotype F63 and the salt-sensitive genotype F35 under 160 mM NaCl treatment for 2 days. Under salinity conditions, the shoot fresh weight and relative water content were significantly higher in F63 than in F35, while the osmotic potential was significantly lower and the reduction of the K+/Na+ ratio was significantly less pronounced in F63 than in F35. Using an iTRAQ approach, twenty-eight proteins showed more than 2.0- fold changes in abundance and were regarded as salt-responsive proteins. Among them, twenty-two were specifically regulated in F63 but remained constant in F35. These proteins were mainly involved in signal processing, water conservation, protein synthesis and biotic cross-tolerance, and could be the major contributors to the tolerant genotype of F63. Functional analysis of a salt-responsive protein was performed in yeast as a case study to confirm the salt-related functions of detected proteins. Taken together, the results of this study may be helpful for further elucidating salt tolerance mechanisms in maize. PMID:25659111

  14. Conversion to No-Till Improves Maize Nitrogen Use Efficiency in a Continuous Cover Cropping System

    PubMed Central

    Habbib, Hazzar; Verzeaux, Julien; Nivelle, Elodie; Roger, David; Lacoux, Jérôme; Catterou, Manuella; Hirel, Bertrand; Dubois, Frédéric; Tétu, Thierry

    2016-01-01

    A two-year experiment was conducted in the field to measure the combined impact of tilling and N fertilization on various agronomic traits related to nitrogen (N) use efficiency and to grain yield in maize cultivated in the presence of a cover crop. Four years after conversion to no-till, a significant increase in N use efficiency N harvest index, N remobilization and N remobilization efficiency was observed both under no and high N fertilization conditions. Moreover, we observed that grain yield and grain N content were higher under no-till conditions only when N fertilizers were applied. Thus, agronomic practices based on continuous no-till appear to be a promising for increasing N use efficiency in maize. PMID:27711154

  15. Advances in Maize Genomics and Their Value for Enhancing Genetic Gains from Breeding

    PubMed Central

    Xu, Yunbi; Skinner, Debra J.; Wu, Huixia; Palacios-Rojas, Natalia; Araus, Jose Luis; Yan, Jianbing; Gao, Shibin; Warburton, Marilyn L.; Crouch, Jonathan H.

    2009-01-01

    Maize is an important crop for food, feed, forage, and fuel across tropical and temperate areas of the world. Diversity studies at genetic, molecular, and functional levels have revealed that, tropical maize germplasm, landraces, and wild relatives harbor a significantly wider range of genetic variation. Among all types of markers, SNP markers are increasingly the marker-of-choice for all genomics applications in maize breeding. Genetic mapping has been developed through conventional linkage mapping and more recently through linkage disequilibrium-based association analyses. Maize genome sequencing, initially focused on gene-rich regions, now aims for the availability of complete genome sequence. Conventional insertion mutation-based cloning has been complemented recently by EST- and map-based cloning. Transgenics and nutritional genomics are rapidly advancing fields targeting important agronomic traits including pest resistance and grain quality. Substantial advances have been made in methodologies for genomics-assisted breeding, enhancing progress in yield as well as abiotic and biotic stress resistances. Various genomic databases and informatics tools have been developed, among which MaizeGDB is the most developed and widely used by the maize research community. In the future, more emphasis should be given to the development of tools and strategic germplasm resources for more effective molecular breeding of tropical maize products. PMID:19688107

  16. Contributions of cultivar shift, management practice and climate change to maize yield in North China Plain in 1981-2009

    NASA Astrophysics Data System (ADS)

    Xiao, Dengpan; Tao, Fulu

    2016-07-01

    The impact of climate change on crop yield is compounded by cultivar shifts and agronomic management practices. To determine the relative contributions of climate change, cultivar shift, and management practice to changes in maize ( Zea mays L.) yield in the past three decades, detailed field data for 1981-2009 from four representative experimental stations in North China Plain (NCP) were analyzed via model simulation. The four representative experimental stations are geographically and climatologically different, represent the typical cropping system in the study area, and have more complete weather/crop records for the period of 1981-2009. The results showed that while the shift from traditional to modern cultivar increased yield by 23.9-40.3 %, new fertilizer management increased yield by 3.3-8.6 %. However, the trends in climate variables for 1981-2009 reduced maize yield by 15-30 % in the study area. Among the main climate variables, solar radiation had the largest effect on maize yield, followed by temperature and then precipitation. While a significant decline in solar radiation in 1981-2009 (maybe due to air pollution) reduced yield by 12-24 %, a significant increase in temperature reduced yield by 3-9 %. In contrast, a non-significant increase in precipitation during the maize growth period increased yield by 0.9-3 % at three of the four investigated stations. However, a decline in precipitation reduced yield by 3 % in the remaining station. The study revealed that although the shift from traditional to modern cultivars and agronomic management practices contributed most to the increase in maize yield, the negative impact of climate change was large enough to offset 46-67 % of the trend in the observed yields in the past three decades in NCP. The reduction in solar radiation, especially in the most critical period of maize growth, limited the process of photosynthesis and thereby further reduced maize yield.

  17. Long-term field phytoextraction of zinc/cadmium contaminated soil by Sedum plumbizincicola under different agronomic strategies.

    PubMed

    Deng, Lin; Li, Zhu; Wang, Jie; Liu, Hongyan; Li, Na; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Christie, Peter

    2016-01-01

    In two long-term field experiments the zinc (Zn)/cadmium (Cd) hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) was examined to optimize the phytoextraction of metal contaminated soil by two agronomic strategies of intercropping with maize (Zea mays) and plant densities. Soil total Zn and Cd concentrations decreased markedly after long-term phytoextraction. But shoot biomass and Cd and Zn concentrations showed no significant difference with increasing remediation time. In the intercropping experiment the phytoremediation efficiency in the treatment "S. plumbizincicola intercropped with maize" was higher than in S. plumbizincicola monocropping, and Cd concentrations of corn were below the maximum national limit. In the plant density experiment the phytoremediation efficiency increased with increasing plant density and 440,000 plants ha(-1) gave the maximum rate. These results indicated that S. plumbizincicola at an appropriate planting density and intercropped with maize can achieve high remediation efficiency to contaminated soil without affecting the cereal crop productivity. This cropping system combines adequate agricultural production with soil heavy metal phytoextraction. PMID:26445166

  18. A genome-wide association study reveals genes associated with fusarium ear rot resistance in a maize core diversity panel.

    PubMed

    Zila, Charles T; Samayoa, L Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B

    2013-11-01

    Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0-100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

  19. Seed-specific expression of the lysine-rich protein gene sb401 significantly increases both lysine and total protein content in maize seeds.

    PubMed

    Yu, Jingjuan; Peng, Peng; Zhang, Xiujun; Zhao, Qian; Zhu, Dengyun; Sun, Xuehui; Liu, Junqi; Ao, Guangming

    2005-12-01

    The sb401 gene from potato (Solanum berthaultii) encoding a pollen-specific protein with high lysine content was successfully integrated into the genome of maize plants, and its expression was correlated with increased levels of lysine and total protein content in maize seeds. A plasmid vector containing the sb401 gene under the control of a maize seed-specific expression storage protein promoter (P19z) was constructed and introduced into maize calli by microprojectile bombardment. The integration of the sb401 gene into the maize genome was confirmed by Southern blot analysis, and its expression was confirmed by Western blot analysis. Quantification of the lysine and protein contents in R1 maize seeds showed that, compared with the nontransgenic maize control, the lysine content increased by 16.1% to 54.8% and the total protein content increased by 11.6% to 39.0%. There were no visible morphological changes in the vegetative parts and seeds of the transgenic maize plants. Lysine and protein analysis of the transgenic maize grains showed that the levels of lysine and total protein remained high for six continuous generations, indicating that the elevated lysine and total protein levels were heritable. These results indicate that the sb401 gene could be successfully employed in breeding programs aimed at improving the nutritional value of maize.

  20. Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.

    PubMed

    Armada, Elisabeth; Azcón, Rosario; López-Castillo, Olga M; Calvo-Polanco, Mónica; Ruiz-Lozano, Juan Manuel

    2015-05-01

    Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize.

  1. Genome-wide recombination dynamics are associated with phenotypic variation in maize.

    PubMed

    Pan, Qingchun; Li, Lin; Yang, Xiaohong; Tong, Hao; Xu, Shutu; Li, Zhigang; Li, Weiya; Muehlbauer, Gary J; Li, Jiansheng; Yan, Jianbing

    2016-05-01

    Meiotic recombination is a major driver of genetic diversity, species evolution, and agricultural improvement. Thus, an understanding of the genetic recombination landscape across the maize (Zea mays) genome will provide insight and tools for further study of maize evolution and improvement. Here, we used c. 50 000 single nucleotide polymorphisms to precisely map recombination events in 12 artificial maize segregating populations. We observed substantial variation in the recombination frequency and distribution along the ten maize chromosomes among the 12 populations and identified 143 recombination hot regions. Recombination breakpoints were partitioned into intragenic and intergenic events. Interestingly, an increase in the number of genes containing recombination events was accompanied by a decrease in the number of recombination events per gene. This kept the overall number of intragenic recombination events nearly invariable in a given population, suggesting that the recombination variation observed among populations was largely attributed to intergenic recombination. However, significant associations between intragenic recombination events and variation in gene expression and agronomic traits were observed, suggesting potential roles for intragenic recombination in plant phenotypic diversity. Our results provide a comprehensive view of the maize recombination landscape, and show an association between recombination, gene expression and phenotypic variation, which may enhance crop genetic improvement.

  2. Agronomic threshold of soil available phosphorus in grey desert soils in Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Wang, B.; Liu, H.; Hao, X. Y.; Wang, X. H.; Sun, J. S.; Li, J. M.; Ma, Y. B.

    2016-08-01

    Based on 23 years of data, yields of maize, wheat and cotton were modelled under different fertilizer management practices and at different levels of available phosphorus (Olsen-P) in soil. Three types of threshold models were used, namely linear-linear (LL), linear- plateau (LP), and Mitscherlich type exponential (Exp). The agronomic thresholds of available phosphorus were 25.4 mgkg-1 for cotton, 14.8 mgkg-1 for wheat, 13.1 mgkg-1 for maize and 25.4 mgkg-1 for the grey desert soil regions of Xinjiang in China as a whole.

  3. Genotypic and phenotypic characterization of isogenic doubled haploid exotic introgression lines in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We characterized the genotypic and phenotypic variation for cell wall digestibility (CWD) and other agronomic traits of 50 backcross 1 generation doubled haploids (BC1DH) lines developed from the Germplasm Enhancement of Maize (GEM) project. These lines consisted of 31 exotic, unadapted maize race...

  4. Attribution of maize yield increase in China to climate change and technological advancement between 1980 and 2010

    NASA Astrophysics Data System (ADS)

    Guo, Jianping; Zhao, Junfang; Wu, Dingrong; Mu, Jia; Xu, Yanhong

    2014-12-01

    Crop yields are affected by climate change and technological advancement. Objectively and quantitatively evaluating the attribution of crop yield change to climate change and technological advancement will ensure sustainable development of agriculture under climate change. In this study, daily climate variables obtained from 553 meteorological stations in China for the period 1961-2010, detailed observations of maize from 653 agricultural meteorological stations for the period 1981-2010, and results using an Agro-Ecological Zones (AEZ) model, are used to explore the attribution of maize (Zea mays L.) yield change to climate change and technological advancement. In the AEZ model, the climatic potential productivity is examined through three step-by-step levels: photosynthetic potential productivity, photosynthetic thermal potential productivity, and climatic potential productivity. The relative impacts of different climate variables on climatic potential productivity of maize from 1961 to 2010 in China are then evaluated. Combined with the observations of maize, the contributions of climate change and technological advancement to maize yield from 1981 to 2010 in China are separated. The results show that, from 1961 to 2010, climate change had a significant adverse impact on the climatic potential productivity of maize in China. Decreased radiation and increased temperature were the main factors leading to the decrease of climatic potential productivity. However, changes in precipitation had only a small effect. The maize yields of the 14 main planting provinces in China increased obviously over the past 30 years, which was opposite to the decreasing trends of climatic potential productivity. This suggests that technological advancement has offset the negative effects of climate change on maize yield. Technological advancement contributed to maize yield increases by 99.6%-141.6%, while climate change contribution was from -41.4% to 0.4%. In particular, the actual

  5. Tracing QTLs for Leaf Blast Resistance and Agronomic Performance of Finger Millet (Eleusine coracana (L.) Gaertn.) Genotypes through Association Mapping and in silico Comparative Genomics Analyses

    PubMed Central

    Ramakrishnan, M.; Antony Ceasar, S.; Duraipandiyan, V.; Vinod, K. K.; Kalpana, Krishnan; Al-Dhabi, N. A.; Ignacimuthu, S.

    2016-01-01

    Finger millet is one of the small millets with high nutritive value. This crop is vulnerable to blast disease caused by Pyricularia grisea, which occurs annually during rainy and winter seasons. Leaf blast occurs at early crop stage and is highly damaging. Mapping of resistance genes and other quantitative trait loci (QTLs) for agronomic performance can be of great use for improving finger millet genotypes. Evaluation of one hundred and twenty-eight finger millet genotypes in natural field conditions revealed that leaf blast caused severe setback on agronomic performance for susceptible genotypes, most significant traits being plant height and root length. Plant height was reduced under disease severity while root length was increased. Among the genotypes, IE4795 showed superior response in terms of both disease resistance and better agronomic performance. A total of seven unambiguous QTLs were found to be associated with various agronomic traits including leaf blast resistance by association mapping analysis. The markers, UGEP101 and UGEP95, were strongly associated with blast resistance. UGEP98 was associated with tiller number and UGEP9 was associated with root length and seed yield. Cross species validation of markers revealed that 12 candidate genes were associated with 8 QTLs in the genomes of grass species such as rice, foxtail millet, maize, Brachypodium stacei, B. distachyon, Panicum hallii and switchgrass. Several candidate genes were found proximal to orthologous sequences of the identified QTLs such as 1,4-β-glucanase for leaf blast resistance, cytokinin dehydrogenase (CKX) for tiller production, calmodulin (CaM) binding protein for seed yield and pectin methylesterase inhibitor (PMEI) for root growth and development. Most of these QTLs and their putatively associated candidate genes are reported for first time in finger millet. On validation, these novel QTLs may be utilized in future for marker assisted breeding for the development of fungal

  6. Tracing QTLs for Leaf Blast Resistance and Agronomic Performance of Finger Millet (Eleusine coracana (L.) Gaertn.) Genotypes through Association Mapping and in silico Comparative Genomics Analyses.

    PubMed

    Ramakrishnan, M; Antony Ceasar, S; Duraipandiyan, V; Vinod, K K; Kalpana, Krishnan; Al-Dhabi, N A; Ignacimuthu, S

    2016-01-01

    Finger millet is one of the small millets with high nutritive value. This crop is vulnerable to blast disease caused by Pyricularia grisea, which occurs annually during rainy and winter seasons. Leaf blast occurs at early crop stage and is highly damaging. Mapping of resistance genes and other quantitative trait loci (QTLs) for agronomic performance can be of great use for improving finger millet genotypes. Evaluation of one hundred and twenty-eight finger millet genotypes in natural field conditions revealed that leaf blast caused severe setback on agronomic performance for susceptible genotypes, most significant traits being plant height and root length. Plant height was reduced under disease severity while root length was increased. Among the genotypes, IE4795 showed superior response in terms of both disease resistance and better agronomic performance. A total of seven unambiguous QTLs were found to be associated with various agronomic traits including leaf blast resistance by association mapping analysis. The markers, UGEP101 and UGEP95, were strongly associated with blast resistance. UGEP98 was associated with tiller number and UGEP9 was associated with root length and seed yield. Cross species validation of markers revealed that 12 candidate genes were associated with 8 QTLs in the genomes of grass species such as rice, foxtail millet, maize, Brachypodium stacei, B. distachyon, Panicum hallii and switchgrass. Several candidate genes were found proximal to orthologous sequences of the identified QTLs such as 1,4-β-glucanase for leaf blast resistance, cytokinin dehydrogenase (CKX) for tiller production, calmodulin (CaM) binding protein for seed yield and pectin methylesterase inhibitor (PMEI) for root growth and development. Most of these QTLs and their putatively associated candidate genes are reported for first time in finger millet. On validation, these novel QTLs may be utilized in future for marker assisted breeding for the development of fungal

  7. Maize databases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

  8. Genetic characterization of the North Carolina State University maize lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1980, 150 North Carolina State University maize inbreds have been developed and released on the basis of superior performance for topcross yield and other traits of agronomic importance. During this time there has been great emphasis placed on breeding with exotic germplasm, with 86 NCSU inbr...

  9. Is the Inherent Potential of Maize Roots Efficient for Soil Phosphorus Acquisition?

    PubMed Central

    Deng, Yan; Chen, Keru; Teng, Wan; Zhan, Ai; Tong, Yiping; Feng, Gu; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

    2014-01-01

    Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg−1, and the threshold indicating a significant environmental risk was about 15 mg kg−1, which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg−1, indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots. PMID:24594677

  10. Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

    PubMed

    Deng, Yan; Chen, Keru; Teng, Wan; Zhan, Ai; Tong, Yiping; Feng, Gu; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

    2014-01-01

    Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1), and the threshold indicating a significant environmental risk was about 15 mg kg(-1), which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1), indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots. PMID:24594677

  11. Heterosis in early maize ear inflorescence development: a genome-wide transcription analysis for two maize inbred lines and their hybrid.

    PubMed

    Ding, Haiping; Qin, Cheng; Luo, Xirong; Li, Lujiang; Chen, Zhe; Liu, Hongjun; Gao, Jian; Lin, Haijian; Shen, Yaou; Zhao, Maojun; Lübberstedt, Thomas; Zhang, Zhiming; Pan, Guangtang

    2014-08-11

    Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17) and their F1 hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs) genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex), five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity), and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization). Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an indication that in

  12. Heterosis in Early Maize Ear Inflorescence Development: A Genome-Wide Transcription Analysis for Two Maize Inbred Lines and Their Hybrid

    PubMed Central

    Ding, Haiping; Qin, Cheng; Luo, Xirong; Li, Lujiang; Chen, Zhe; Liu, Hongjun; Gao, Jian; Lin, Haijian; Shen, Yaou; Zhao, Maojun; Lübberstedt, Thomas; Zhang, Zhiming; Pan, Guangtang

    2014-01-01

    Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17) and their F1 hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs) genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex), five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity), and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization). Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an indication that in

  13. Biochar: a synthesis of its agronomic impact beyond carbon sequestration.

    PubMed

    Spokas, Kurt A; Cantrell, Keri B; Novak, Jeffrey M; Archer, David W; Ippolito, James A; Collins, Harold P; Boateng, Akwasi A; Lima, Isabel M; Lamb, Marshall C; McAloon, Andrew J; Lentz, Rodrick D; Nichols, Kristine A

    2012-01-01

    Biochar has been heralded as an amendment to revitalize degraded soils, improve soil carbon sequestration, increase agronomic productivity, and enter into future carbon trading markets. However, scientific and economic technicalties may limit the ability of biochar to consistently deliver on these expectations. Past research has demonstrated that biochar is part of the black carbon continuum with variable properties due to the net result of production (e.g., feedstock and pyrolysis conditions) and postproduction factors (storage or activation). Therefore, biochar is not a single entity but rather spans a wide range of black carbon forms. Biochar is black carbon, but not all black carbon is biochar. Agronomic benefits arising from biochar additions to degraded soils have been emphasized, but negligible and negative agronomic effects have also been reported. Fifty percent of the reviewed studies reported yield increases after black carbon or biochar additions, with the remainder of the studies reporting alarming decreases to no significant differences. Hardwood biochar (black carbon) produced by traditional methods (kilns or soil pits) possessed the most consistent yield increases when added to soils. The universality of this conclusion requires further evaluation due to the highly skewed feedstock preferences within existing studies. With global population expanding while the amount of arable land remains limited, restoring soil quality to nonproductive soils could be key to meeting future global food production, food security, and energy supplies; biochar may play a role in this endeavor. Biochar economics are often marginally viable and are tightly tied to the assumed duration of agronomic benefits. Further research is needed to determine the conditions under which biochar can provide economic and agronomic benefits and to elucidate the fundamental mechanisms responsible for these benefits. PMID:22751040

  14. A rare SNP mutation in Brachytic2 moderately reduces plant height and increases yield potential in maize.

    PubMed

    Xing, Anqi; Gao, Yufeng; Ye, Lingfeng; Zhang, Weiping; Cai, Lichun; Ching, Ada; Llaca, Victor; Johnson, Blaine; Liu, Lin; Yang, Xiaohong; Kang, Dingming; Yan, Jianbing; Li, Jiansheng

    2015-07-01

    Plant height has long been an important agronomic trait in maize breeding. Many plant height QTLs have been reported, but few of these have been cloned. In this study, a major plant height QTL, qph1, was mapped to a 1.6kb interval in Brachytic2 (Br2) coding sequence on maize chromosome 1. A naturally occurring rare SNP in qph1, which resulted in an amino acid substitution, was validated as the causative mutation. QPH1 protein is located in the plasma membrane and polar auxin transport is impaired in the short near-isogenic line RIL88(qph1). Allelism testing showed that the SNP variant in qph1 reduces longitudinal cell number and decreases plant height by 20% in RIL88(qph1) compared to RIL88(QPH1), and is milder than known br2 mutant alleles. The effect of qph1 on plant height is significant and has no or a slight influence on yield in four F2 backgrounds and in six pairs of single-cross hybrids. Moreover, qph1 could reduce plant height when heterozygous, allowing it to be easily employed in maize breeding. Thus, a less-severe allele of a known dwarf mutant explains part of the quantitative variation for plant height and has great potential in maize improvement.

  15. Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.

    PubMed

    Armada, Elisabeth; Azcón, Rosario; López-Castillo, Olga M; Calvo-Polanco, Mónica; Ruiz-Lozano, Juan Manuel

    2015-05-01

    Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize. PMID:25813343

  16. Agronomic use of biotechnologically processed grape wastes.

    PubMed

    Ferrer, J; Páez, G; Mármol, Z; Ramones, E; Chandler, C; Marín, M; Ferrer, A

    2001-01-01

    Grape waste was composted by biodegradation and subsequently used as an organic fertilizer for 20 day-corn. Combinations of recently compressed grape waste and hen droppings (10% w/w) were prepared to study the activating effect of hen droppings and the effect of aeration on the composting process. The final hydrogen potential (pH), %C, %N and C/N ratio, indicated an adequate development of the bioprocess. Satisfactory results were observed when the products were applied at several doses (1,000-4,000 kg/ ha) as a soil conditioner for corn seed germination in greenhouses. Only the addition of hen droppings had a significant effect (P < 0.05) on corn dry matter (14% increase). A dose of 3000 kg/ha was considered as optimal and was used supplemented with triple superphosphate (TSP) in agronomic trials. All the treatments produced greater corn dry matter (P < 0.05) than the chemical industrial fertilizer used as a control (0.52-0.71 g/pot for the organic fertilizers vs 0.45 g/pot for the control). Anaerobic conditions and hen droppings addition significantly produced (P < 0.05) higher corn dry matter. PMID:11315808

  17. Global maize production, utilization, and consumption.

    PubMed

    Ranum, Peter; Peña-Rosas, Juan Pablo; Garcia-Casal, Maria Nieves

    2014-04-01

    Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification. PMID:24650320

  18. Global maize production, utilization, and consumption.

    PubMed

    Ranum, Peter; Peña-Rosas, Juan Pablo; Garcia-Casal, Maria Nieves

    2014-04-01

    Maize (Zea mays), also called corn, is believed to have originated in central Mexico 7000 years ago from a wild grass, and Native Americans transformed maize into a better source of food. Maize contains approximately 72% starch, 10% protein, and 4% fat, supplying an energy density of 365 Kcal/100 g and is grown throughout the world, with the United States, China, and Brazil being the top three maize-producing countries in the world, producing approximately 563 of the 717 million metric tons/year. Maize can be processed into a variety of food and industrial products, including starch, sweeteners, oil, beverages, glue, industrial alcohol, and fuel ethanol. In the last 10 years, the use of maize for fuel production significantly increased, accounting for approximately 40% of the maize production in the United States. As the ethanol industry absorbs a larger share of the maize crop, higher prices for maize will intensify demand competition and could affect maize prices for animal and human consumption. Low production costs, along with the high consumption of maize flour and cornmeal, especially where micronutrient deficiencies are common public health problems, make this food staple an ideal food vehicle for fortification.

  19. Effects of controlled-release fertiliser on nitrogen use efficiency in summer maize.

    PubMed

    Zhao, Bin; Dong, Shuting; Zhang, Jiwang; Liu, Peng

    2013-01-01

    Nitrogen (N) is a nutrient element necessary for plant growth and development. However, excessive inputs of N will lead to inefficient use and large N losses to the environment, which can adversely affect air and water quality, biodiversity and human health. To examine the effects of controlled-release fertilisers (CRF) on yield, we measured ammonia volatilisation, N use efficiency (NUE) and photosynthetic rate after anthesis in summer maize hybrid cultivar Zhengdan958. Maize was grown using common compound fertiliser (CCF), the same amount of resin-coated controlled release fertiliser (CRFIII), the same amount of sulphur-coated controlled release fertiliser (SCFIII) as CCF, 75% CRF (CRFII) and SCF (SCFII), 50% CRF (CRFI) and SCF (SCFI), and no fertiliser. We found that treatments CRFIII, SCFIII, CRFII and SCFII produced grain yields that were 13.15%, 14.15%, 9.69% and 10.04% higher than CCF. There were no significant differences in grain yield among CRFI, SCFI and CCF. We also found that the ammonia volatilisation rates of CRF were significantly lower than those of CCF. The CRF treatments reduced the emission of ammonia by 51.34% to 91.34% compared to CCF. In addition, after treatment with CRF, maize exhibited a higher net photosynthetic rate than CCF after anthesis. Agronomic NUE and apparent N recovery were higher in the CRF treatment than in the CCF treatment. The N uptake and physiological NUE of the four yield-enhanced CRF treatments were higher than those of CCF. These results suggest that the increase in NUE in the CRF treatments was generally attributable to the higher photosynthetic rate and lower ammonia volatilisation compared to CCF-treated maize. PMID:23936449

  20. Effects of Controlled-Release Fertiliser on Nitrogen Use Efficiency in Summer Maize

    PubMed Central

    Zhao, Bin; Dong, Shuting; Zhang, Jiwang; Liu, Peng

    2013-01-01

    Nitrogen (N) is a nutrient element necessary for plant growth and development. However, excessive inputs of N will lead to inefficient use and large N losses to the environment, which can adversely affect air and water quality, biodiversity and human health. To examine the effects of controlled-release fertilisers (CRF) on yield, we measured ammonia volatilisation, N use efficiency (NUE) and photosynthetic rate after anthesis in summer maize hybrid cultivar Zhengdan958. Maize was grown using common compound fertiliser (CCF), the same amount of resin-coated controlled release fertiliser (CRFIII), the same amount of sulphur-coated controlled release fertiliser (SCFIII) as CCF, 75% CRF (CRFII) and SCF (SCFII), 50% CRF (CRFI) and SCF (SCFI), and no fertiliser. We found that treatments CRFIII, SCFIII, CRFII and SCFII produced grain yields that were 13.15%, 14.15%, 9.69% and 10.04% higher than CCF. There were no significant differences in grain yield among CRFI, SCFI and CCF. We also found that the ammonia volatilisation rates of CRF were significantly lower than those of CCF. The CRF treatments reduced the emission of ammonia by 51.34% to 91.34% compared to CCF. In addition, after treatment with CRF, maize exhibited a higher net photosynthetic rate than CCF after anthesis. Agronomic NUE and apparent N recovery were higher in the CRF treatment than in the CCF treatment. The N uptake and physiological NUE of the four yield-enhanced CRF treatments were higher than those of CCF. These results suggest that the increase in NUE in the CRF treatments was generally attributable to the higher photosynthetic rate and lower ammonia volatilisation compared to CCF-treated maize. PMID:23936449

  1. Effects of controlled-release fertiliser on nitrogen use efficiency in summer maize.

    PubMed

    Zhao, Bin; Dong, Shuting; Zhang, Jiwang; Liu, Peng

    2013-01-01

    Nitrogen (N) is a nutrient element necessary for plant growth and development. However, excessive inputs of N will lead to inefficient use and large N losses to the environment, which can adversely affect air and water quality, biodiversity and human health. To examine the effects of controlled-release fertilisers (CRF) on yield, we measured ammonia volatilisation, N use efficiency (NUE) and photosynthetic rate after anthesis in summer maize hybrid cultivar Zhengdan958. Maize was grown using common compound fertiliser (CCF), the same amount of resin-coated controlled release fertiliser (CRFIII), the same amount of sulphur-coated controlled release fertiliser (SCFIII) as CCF, 75% CRF (CRFII) and SCF (SCFII), 50% CRF (CRFI) and SCF (SCFI), and no fertiliser. We found that treatments CRFIII, SCFIII, CRFII and SCFII produced grain yields that were 13.15%, 14.15%, 9.69% and 10.04% higher than CCF. There were no significant differences in grain yield among CRFI, SCFI and CCF. We also found that the ammonia volatilisation rates of CRF were significantly lower than those of CCF. The CRF treatments reduced the emission of ammonia by 51.34% to 91.34% compared to CCF. In addition, after treatment with CRF, maize exhibited a higher net photosynthetic rate than CCF after anthesis. Agronomic NUE and apparent N recovery were higher in the CRF treatment than in the CCF treatment. The N uptake and physiological NUE of the four yield-enhanced CRF treatments were higher than those of CCF. These results suggest that the increase in NUE in the CRF treatments was generally attributable to the higher photosynthetic rate and lower ammonia volatilisation compared to CCF-treated maize.

  2. Maize: Overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is an important cereal crop that is well-suited to industrial agriculture, both in grain production and in grain utilization. Starch, protein and oil are the three major components of the grain. Several processing methods yield many different food ingredients. In addition, whole grain is pr...

  3. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  4. Core Promoter Plasticity Between Maize Tissues and Genotypes Contrasts with Predominance of Sharp Transcription Initiation Sites[OPEN

    PubMed Central

    Li, Wei; Vidal, Mabel; Gray, John; Doseff, Andrea I.; Grotewold, Erich

    2015-01-01

    Core promoters are crucial for gene regulation, providing blueprints for the assembly of transcriptional machinery at transcription start sites (TSSs). Empirically, TSSs define the coordinates of core promoters and other regulatory sequences. Thus, experimental TSS identification provides an essential step in the characterization of promoters and their features. Here, we describe the application of CAGE (cap analysis of gene expression) to identify genome-wide TSSs used in root and shoot tissues of two maize (Zea mays) inbred lines (B73 and Mo17). Our studies indicate that most TSS clusters are sharp in maize, similar to mice, but distinct from Arabidopsis thaliana, Drosophila melanogaster, or zebra fish, in which a majority of genes have broad-shaped TSS clusters. We established that ∼38% of maize promoters are characterized by a broader TATA-motif consensus, and this motif is significantly enriched in genes with sharp TSSs. A noteworthy plasticity in TSS usage between tissues and inbreds was uncovered, with ∼1500 genes showing significantly different dominant TSSs, sometimes affecting protein sequence by providing alternate translation initiation codons. We experimentally characterized instances in which this differential TSS utilization results in protein isoforms with additional domains or targeted to distinct subcellular compartments. These results provide important insights into TSS selection and gene expression in an agronomically important crop. PMID:26628745

  5. Overexpression of a Fungal β-Mannanase from Bispora sp. MEY-1 in Maize Seeds and Enzyme Characterization

    PubMed Central

    Meng, Qingchang; Meng, Kun; Zhang, Wei; Zhou, Xiaojin; Luo, Huiying; Chen, Rumei; Yang, Peilong; Yao, Bin

    2013-01-01

    Background Mannans and heteromannans are widespread in plants cell walls and are well-known as anti-nutritional factors in animal feed. To remove these factors, it is common practice to incorporate endo-β-mannanase into feed for efficient nutrition absorption. The objective of this study was to overexpress a β-mannanase gene directly in maize, the main ingredient of animal feed, to simplify the process of feed production. Methodology/Principal Findings The man5A gene encoding an excellent β-mannanase from acidophilic Bispora sp. MEY-1 was selected for heterologous overexpression. Expression of the modified gene (man5As) was driven by the embryo-specific promoter ZM-leg1A, and the transgene was transferred to three generations by backcrossing with commercial inbred Zheng58. Its exogenous integration into the maize embryonic genome and tissue specific expression in seeds were confirmed by PCR and Southern blot and Western blot analysis, respectively. Transgenic plants at BC3 generation showed agronomic traits statistically similar to Zheng58 except for less plant height (154.0 cm vs 158.3 cm). The expression level of MAN5AS reached up to 26,860 units per kilogram of maize seeds. Compared with its counterpart produced in Pichia pastoris, seed-derived MAN5AS had higher temperature optimum (90°C), and remained more β-mannanase activities after pelleting at 80°C, 100°C or 120°C. Conclusion/Significance This study shows the genetically stable overexpression of a fungal β-mannanase in maize and offers an effective and economic approach for transgene containment in maize for direct utilization without any purification or supplementation procedures. PMID:23409143

  6. Evaluation of maize yield in an on-farm maize-soybean and maize-Lablab crop rotation systems in the Northern Guinea Savanna of Nigeria.

    PubMed

    Okogun, J A; Sanginga, N; Abaidoo, R C

    2007-11-01

    An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS) of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-cycle of soybean/maize and Lablab/maize crop rotation in NGS Nigeria was assessed in researcher-managed and farmer-managed plots. Though maize that followed the soybean received between 5 kg N ha(-1) from improved soybean variety (TGx 1448-2E) and 17 kg N ha(-1) from farmer soybean variety (Samsoy-2) as N balance, this did not significantly (p = 0.05) affect the maize yields. The soybean shed 90-100% of its leaves at physiological maturity which resulted in about 110 kg N ha(-1) N uptake. This source of N might be one of the factors responsible for the increase in maize yield that followed soybean (20 to 24%) compared with continuous maize yield plot. Maize yield in previous Lablab plot was significantly (p = 0.05) higher than in all other treatments. Maize yield in farmer-managed plot ranged between 0.13 and 4.53 t ha(-1), maize yield in researcher-managed plot was over 200% higher than maize yield in farmer-managed plot because of poor crop management on the part of the farmer.

  7. [Effects of nitrogen management on maize nitrogen utilization and residual nitrate nitrogen in soil under maize/soybean and maize/sweet potato relay strip intercropping systems].

    PubMed

    Wang, Xiao-Chun; Yang, Wen-Yu; Deng, Xiao-Yan; Zhang, Qun; Yong, Tai-Wen; Liu, Wei-Guo; Yang, Feng; Mao, Shu-Ming

    2014-10-01

    A large amount of nitrogen (N) fertilizers poured into the fields severely pollute the environment. Reasonable application of N fertilizer has always been the research hotpot. The effects of N management on maize N utilization and residual nitrate N in soil under maize/soybean and maize/ sweet potato relay strip intercropping systems were reported in a field experiment in southwest China. It was found that maize N accumulation, N harvest index, N absorption efficiency, N contribution proportion after the anthesis stage in maize/soybean relay strip intercropping were increased by 6.1%, 5.4%, 4.3%, and 15.1% than under maize/sweet potato with an increase of 22.6% for maize yield after sustainable growing of maize/soybean intercropping system. Nitrate N accumulation in the 0-60 cm soil layer was 12.9% higher under maize/soybean intercropping than under maize/sweet potato intercropping. However, nitrate N concentration in the 60-120 cm soil layer when intercropped with soybean decreased by 10.3% than when intercropped with sweet potato, indicating a decrease of N leaching loss. Increasing of N application rate enhanced N accumulation of maize and decreased N use efficiency and significantly increased nitrate concentration in the soil profile except in the 60-100 cm soil layer, where no significant difference was observed with nitrogen application rate at 0 to 270 kg · hm(-2). Further application of N fertilizer significantly enhanced nitrate leaching loss. Postponing N application increased nitrate accumulation in the 60-100 cm soil layer. The results suggested that N application rates and ratio of base to top dressing had different influences on maize N concentration and nitrate N between maize/soybean and maize/sweet potato intercropping. Maize N concentration in the late growing stage, N harvest index and N use efficiency under maize/soybean intercropping increased (with N application rate at 180-270 kg · hm(-2) and ratio of base to top dressing = 3:2:5) and

  8. Effects of salts on the gelatinization and retrogradation properties of maize starch and waxy maize starch.

    PubMed

    Wang, Wei; Zhou, Hongxian; Yang, Hong; Zhao, Siming; Liu, Youming; Liu, Ru

    2017-01-01

    The objective of this study was to evaluate the effects of salts on the gelatinization and retrogradation of maize and waxy maize starch. Experimental results showed that the salting-out or structure-making ions, such as F(-) and SO4(2-), decreased the swelling power, solubility and transparency of both starches, but increased the gelatinization temperature, enthalpy, and syneresis, due to the tendency of these ions to protect the hydrogen bond links among starch molecules. On the other hand, the salting-in or structure-breaking ions, such as I(-) and SCN(-), exhibited the opposite effects. Microscopic observations confirmed such effects of salts on both starches. Furthermore, the effects of salts were more significant on waxy maize and on normal maize starch. Generally, salts could significantly influence on the gelatinization and retrogradation of maize and waxy maize starch, following the order of the Hofmeister series. PMID:27507481

  9. A crop population perspective on maize seed systems in Mexico

    PubMed Central

    Dyer, George A.; Taylor, J. Edward

    2008-01-01

    Improvement of local germplasm through artificial selection is regarded as the main force behind maize evolution and diversity in Mexico, the crop's center of origin. This perspective neglects the larger social context of maize evolution. Using a theoretical approach and Mexico-wide data, we show that farmer-led evolution of maize is largely driven by a technological diffusion and appropriation process that selectively integrates nonlocal germplasm into local seed stocks. Our approach construes farmer practices as events in the life history of seed to build a demographic model. The model shows how random and systematic differences in management combine to structure maize seed populations into subpopulations that can spread or become extinct, in some cases independently of visible agronomic advantages. The process involves continuous population bottlenecks that can lead to diversity loss. Nonlocal germplasm thus might play a critical role in maintaining diversity in individual localities. Empirical estimates show that introduction of nonlocal seed in Central and Southeastern Mexico is rarer than previously thought; prompt replacement further prevents new seed from spreading. Yet introduced seed perceived as valuable diffuses rapidly, contributing variation in the form of type diversity or through introgression into local seed. Maize seed dynamics and evolution are thus part of a complex social process driven by farmers' desire to appropriate the value in maize farming, not always achieved by preserving or improving local seed stocks. PMID:18184814

  10. Developing Resistance to Aflatoxin in Maize and Cottonseed

    PubMed Central

    Cary, Jeffrey W.; Rajasekaran, Kanniah; Brown, Robert L.; Luo, Meng; Chen, Zhi-Yuan; Bhatnagar, Deepak

    2011-01-01

    At this time, no “magic bullet” for solving the aflatoxin contamination problem in maize and cottonseed has been identified, so several strategies must be utilized simultaneously to ensure a healthy crop, free of aflatoxins. The most widely explored strategy for the control of aflatoxin contamination is the development of preharvest host resistance. This is because A. flavus infects and produces aflatoxins in susceptible crops prior to harvest. In maize production, the host resistance strategy has gained prominence because of advances in the identification of natural resistance traits. However, native resistance in maize to aflatoxin contamination is polygenic and complex and, therefore, markers need to be identified to facilitate the transfer of resistance traits into agronomically viable genetic backgrounds while limiting the transfer of undesirable traits. Unlike maize, there are no known cotton varieties that demonstrate enhanced resistance to A. flavus infection and aflatoxin contamination. For this reason, transgenic approaches are being undertaken in cotton that utilize genes encoding antifungal/anti-aflatoxin factors from maize and other sources to counter fungal infection and toxin production. This review will present information on preharvest control strategies that utilize both breeding and native resistance identification approaches in maize as well as transgenic approaches in cotton. PMID:22069734

  11. Developing resistance to aflatoxin in maize and cottonseed.

    PubMed

    Cary, Jeffrey W; Rajasekaran, Kanniah; Brown, Robert L; Luo, Meng; Chen, Zhi-Yuan; Bhatnagar, Deepak

    2011-06-01

    At this time, no "magic bullet" for solving the aflatoxin contamination problem in maize and cottonseed has been identified, so several strategies must be utilized simultaneously to ensure a healthy crop, free of aflatoxins. The most widely explored strategy for the control of aflatoxin contamination is the development of preharvest host resistance. This is because A. flavus infects and produces aflatoxins in susceptible crops prior to harvest. In maize production, the host resistance strategy has gained prominence because of advances in the identification of natural resistance traits. However, native resistance in maize to aflatoxin contamination is polygenic and complex and, therefore, markers need to be identified to facilitate the transfer of resistance traits into agronomically viable genetic backgrounds while limiting the transfer of undesirable traits. Unlike maize, there are no known cotton varieties that demonstrate enhanced resistance to A. flavus infection and aflatoxin contamination. For this reason, transgenic approaches are being undertaken in cotton that utilize genes encoding antifungal/anti-aflatoxin factors from maize and other sources to counter fungal infection and toxin production. This review will present information on preharvest control strategies that utilize both breeding and native resistance identification approaches in maize as well as transgenic approaches in cotton. PMID:22069734

  12. [Effects of intercropping different crops with maize on the Cd uptake by maize].

    PubMed

    Li, Ning-Yu; Li, Zhi-An; Ding, Yong-Zhen; Zou, Bi; Zhuang, Ping

    2008-06-01

    A greenhouse experiment was conducted to investigate the effects of intercropping 7 kinds of crops on the Cd uptake by maize (Zea mays L.). The results showed that most intercrops had no significant effects on the growth of maize, only with purple haricot reduced the maize biomass by 32.2% of the control. Legume crops enhanced the total quantity of Cd in maize in a great magnitude, and chickpea worked most efficiently, which doubled the Cd quantity in maize. The 7 intercrops showed different capability of Cd uptake, among which, rape and amaranth absorbed larger amount of Cd, with a Cd level of 53.9 mg x kg(-1) and 51.0 mg x kg(-1) in their aboveground parts, respectively, and of 91.8 mg x kg(-1) in amaranth root when the soil Cd content was 3 mg x kg(-1) soil. There was an interaction between maize and intercrops in Cd uptake. Legumes absorbed smaller amount of Cd but significantly increased the Cd uptake by maize, while amaranth was in adverse. Rape had a higher level of Cd concentration in its shoot, but reduced the Cd in aboveground part of maize. It was indicated that if maize was used for phytoremediation of Cd-contaminated soil, a higher efficiency of Cd removal could be achieved by intercropping it with legumes. Rape and amaranth could be the two promising plants for phytoremediation because of their high Cd accumulation. PMID:18808034

  13. Fate of atrazine in a soil under different agronomic management practices.

    PubMed

    Prado, B; Fuentes, M; Verhulst, N; Govaerts, B; De León, F; Zamora, O

    2014-01-01

    Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficient Kd (1.1 L kg(-1)) at 0-10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highest Kd values were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg(-1), respectively). Under zero tillage, the fact that there was no soil movement helped to increase the Kd. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (Kd ranged from 30 to 40 L kg(-1)). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area. PMID:25190559

  14. Historical genomics of North American maize

    PubMed Central

    van Heerwaarden, Joost; Hufford, Matthew B.; Ross-Ibarra, Jeffrey

    2012-01-01

    Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density SNP genotyping to characterize a set of North American maize lines spanning the history of modern breeding. We provide a unique analysis of genome-wide developments in genetic diversity, ancestry, and selection. The genomic history of maize is marked by a steady increase in genetic differentiation and linkage disequilibrium, whereas allele frequencies in the total population have remained relatively constant. These changes are associated with increasing genetic separation of breeding pools and decreased diversity in the ancestry of individual lines. We confirm that modern heterotic groups are the product of ongoing divergence from a relatively homogeneous landrace population, but show that differential landrace ancestry remains evident. Using a recent association approach, we characterize signals of directional selection throughout the genome, identifying a number of candidate genes of potential agronomic relevance. However, overall we find that selection has had limited impact on genome-wide patterns of diversity and ancestry, with little evidence for individual lines contributing disproportionately to the accumulation of favorable alleles in today's elite germplasm. Our data suggest breeding progress has mainly involved selection and recombination of relatively common alleles, contributed by a representative but limited set of ancestral lines. PMID:22802642

  15. [Effects of stereoscopic cultivation on soil microorganism, enzyme activity and the agronomic characters of Panax notoginseng].

    PubMed

    Liao, Pei-ran; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Compartments of soil microorganism and enzymes between stereoscopic cultivation (three storeys) and field cultivation (CK) of Panax notoginseng were carried out, and the effects on P. notoginseng agronomic characters were also studied. Results show that concentration of soil microorganism of stereoscopic cultivation was lower than field cultivation; the activity of soil urea enzyme, saccharase and neutral phosphatase increased from lower storey to upper storey; the activity of soil urea enzyme and saccharase of lower and upper storeys were significantly lower than CK; agronomic characters of stereoscopic cultivated P. notoginsengin were inferior to field cultivation, the middle storey with the best agronomic characters among the three storeys. The correlation analysis showed that fungi, actinomycetes and neutral phosphatase were significantly correlated with P. notoginseng agronomic characters; concentration of soil fungi and bacteria were significantly correlated with the soil relative water content; actinomycete and neutral phosphatase were significantly correlated with soil pH and relative water content, respectively; the activities of soil urea enzyme and saccharase were significantly correlated with the soil daily maximum temperature difference. Inconclusion, The current research shows that the imbalance of soil microorganism and the acutely changing of soil enzyme activity were the main reasons that caused the agronomic characters of stereoscopic cultivated P. notoginseng were worse than field cultivation. Thus improves the concentration of soil microorganism and enzyme activity near to field soil by improving the structure of stereoscopic cultivation is very important. And it was the direction which we are endeavoring that built better soil ecological environment for P. notoginseng of stereoscopic cultivation.

  16. [Effects of stereoscopic cultivation on soil microorganism, enzyme activity and the agronomic characters of Panax notoginseng].

    PubMed

    Liao, Pei-ran; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Compartments of soil microorganism and enzymes between stereoscopic cultivation (three storeys) and field cultivation (CK) of Panax notoginseng were carried out, and the effects on P. notoginseng agronomic characters were also studied. Results show that concentration of soil microorganism of stereoscopic cultivation was lower than field cultivation; the activity of soil urea enzyme, saccharase and neutral phosphatase increased from lower storey to upper storey; the activity of soil urea enzyme and saccharase of lower and upper storeys were significantly lower than CK; agronomic characters of stereoscopic cultivated P. notoginsengin were inferior to field cultivation, the middle storey with the best agronomic characters among the three storeys. The correlation analysis showed that fungi, actinomycetes and neutral phosphatase were significantly correlated with P. notoginseng agronomic characters; concentration of soil fungi and bacteria were significantly correlated with the soil relative water content; actinomycete and neutral phosphatase were significantly correlated with soil pH and relative water content, respectively; the activities of soil urea enzyme and saccharase were significantly correlated with the soil daily maximum temperature difference. Inconclusion, The current research shows that the imbalance of soil microorganism and the acutely changing of soil enzyme activity were the main reasons that caused the agronomic characters of stereoscopic cultivated P. notoginseng were worse than field cultivation. Thus improves the concentration of soil microorganism and enzyme activity near to field soil by improving the structure of stereoscopic cultivation is very important. And it was the direction which we are endeavoring that built better soil ecological environment for P. notoginseng of stereoscopic cultivation. PMID:26677687

  17. Know your community - Biochar: agronomic and environmental uses community

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The “Biochar: Agronomic and Environmental Uses” Community was formed in November 2010 (https://www.agronomy.org/membership/communities/biochar-agronomic-and-environmental-uses). The community’s initial function has been providing a forum at the tri-society’s national meetings to fill the need for a ...

  18. Network analysis of maize RNA transport pathway genes associated with maize resistance to aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is a pathogenic fungus producing alfatoxins that cause significant economic losses in maize production. This study analyzes the differences in expression levels of maize genes in response to A. flavus infection and aflatoxin accumulation. Identification of defense related genes an...

  19. Breakthrough in chloroplast genetic engineering of agronomically important crops

    PubMed Central

    Daniell, Henry; Kumar, Shashi; Dufourmantel, Nathalie

    2012-01-01

    Chloroplast genetic engineering offers several unique advantages, including high-level transgene expression, multi-gene engineering in a single transformation event and transgene containment by maternal inheritance, as well as a lack of gene silencing, position and pleiotropic effects and undesirable foreign DNA. More than 40 transgenes have been stably integrated and expressed using the tobacco chloroplast genome to confer desired agronomic traits or express high levels of vaccine antigens and biopharmaceuticals. Despite such significant progress, this technology has not been extended to major crops. However, highly efficient soybean, carrot and cotton plastid transformation has recently been accomplished through somatic embryogenesis using species-specific chloroplast vectors. This review focuses on recent exciting developments in this field and offers directions for further research and development. PMID:15866001

  20. Reshaping of the maize transcriptome by domestication.

    PubMed

    Swanson-Wagner, Ruth; Briskine, Roman; Schaefer, Robert; Hufford, Matthew B; Ross-Ibarra, Jeffrey; Myers, Chad L; Tiffin, Peter; Springer, Nathan M

    2012-07-17

    Through domestication, humans have substantially altered the morphology of Zea mays ssp. parviglumis (teosinte) into the currently recognizable maize. This system serves as a model for studying adaptation, genome evolution, and the genetics and evolution of complex traits. To examine how domestication has reshaped the transcriptome of maize seedlings, we used expression profiling of 18,242 genes for 38 diverse maize genotypes and 24 teosinte genotypes. We detected evidence for more than 600 genes having significantly different expression levels in maize compared with teosinte. Moreover, more than 1,100 genes showed significantly altered coexpression profiles, reflective of substantial rewiring of the transcriptome since domestication. The genes with altered expression show a significant enrichment for genes previously identified through population genetic analyses as likely targets of selection during maize domestication and improvement; 46 genes previously identified as putative targets of selection also exhibit altered expression levels and coexpression relationships. We also identified 45 genes with altered, primarily higher, expression in inbred relative to outcrossed teosinte. These genes are enriched for functions related to biotic stress and may reflect responses to the effects of inbreeding. This study not only documents alterations in the maize transcriptome following domestication, identifying several genes that may have contributed to the evolution of maize, but highlights the complementary information that can be gained by combining gene expression with population genetic analyses.

  1. MaizeCyc: Metabolic networks in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

  2. Mortality of western corn rootworm larvae on MIR604 transgenic maize roots: field survivorship has no significant impact on survivorship of F1 progeny on MIR604.

    PubMed

    Hibbard, Bruce E; Clark, Thomas L; Ellersieck, Mark R; Meihls, Lisa N; El Khishen, Ahmed A; Kaster, Von; Steiner, Henry-York; Kurtz, Ryan

    2010-12-01

    Mortality of western corn rootworm, Diabrotica virgifera virgifera LeConte, larvae due to MIR604 transgenic corn, Zea mays L., expressing the modified Cry3A (mCry3A) protein relative to survivorship on corn with the same genetic background without the gene (isoline corn) was evaluated at three Missouri sites in both 2005 and 2006. We made these comparisons by using wild-type western corn rootworm at three different egg densities (6,000, 3,000, and 1,500 eggs per m) so that the role of density-dependent mortality would be known. The mortality due to the mCry3A protein was 94.88% when averaged across all environments and both years. Fifty percent emergence of beetles was delayed approximately 5.5 d. Beetles were kept alive and their progeny evaluated on MIR604 and isoline corn in the greenhouse to determine whether survivorship on MIR604 in the field for one generation increased survivorship on MIR604 in the greenhouse in the subsequent generation. There was no significant difference in survivorship on MIR604 in greenhouse assays between larvae whose parents survived isoline and larvae whose parents survived MIR604 in the field the previous generation, indicating that many susceptible beetles survived MIR604 in the field the previous season along with any potentially resistant beetles. The data are discussed in terms of rootworm insect resistance management.

  3. Characterization of selenium-enriched wheat by agronomic biofortification.

    PubMed

    Galinha, Catarina; Sánchez-Martínez, María; Pacheco, Adriano M G; Freitas, Maria do Carmo; Coutinho, José; Maçãs, Benvindo; Almeida, Ana Sofia; Pérez-Corona, María Teresa; Madrid, Yolanda; Wolterbeek, Hubert T

    2015-07-01

    Agronomic biofortification of staple crops is an effective way to enhance their contents in essential nutrients up the food chain, with a view to correcting for their deficiencies in animal or human status. Selenium (Se) is one such case, for its uneven distribution in the continental crust and, therefore, in agricultural lands easily translates into substantial variation in nutritional intakes. Cereals are far from being the main sources of Se on a content basis, but they are likely the major contributors to intake on a dietary basis. To assess their potential to assimilate and biotransform Se, bread and durum wheat were enriched with Se through foliar and soil addition at an equivalent field rate of 100 g of Se per hectare (ha), using sodium selenate and sodium selenite as Se-supplementation matrices, in actual field conditions throughout. Biotransformation of inorganic Se was evaluated by using HPLC-ICP-MS after enzymatic hydrolysis for Se-species extraction in the resulting mature wheat grains. Selenomethionine and Se(VI) were identified and quantified: the former was the predominant species, representing 70-100 % of the total Se in samples; the maximum amount of inorganic Se was below 5 %. These results were similar for both supplementation methods and for both wheat varieties. Judging from the present results, one can conclude that agronomic biofortification of wheat may improve the nutritional quality of wheat grains with significant amounts of selenomethionine, which is an attractive option for increasing the Se status in human diets through Se-enriched, wheat-based foodstuff.

  4. Greater sensitivity to drought accompanies maize yield increase in the U.S. Midwest.

    PubMed

    Lobell, David B; Roberts, Michael J; Schlenker, Wolfram; Braun, Noah; Little, Bertis B; Rejesus, Roderick M; Hammer, Graeme L

    2014-05-01

    A key question for climate change adaptation is whether existing cropping systems can become less sensitive to climate variations. We use a field-level data set on maize and soybean yields in the central United States for 1995 through 2012 to examine changes in drought sensitivity. Although yields have increased in absolute value under all levels of stress for both crops, the sensitivity of maize yields to drought stress associated with high vapor pressure deficits has increased. The greater sensitivity has occurred despite cultivar improvements and increased carbon dioxide and reflects the agronomic trend toward higher sowing densities. The results suggest that agronomic changes tend to translate improved drought tolerance of plants to higher average yields but not to decreasing drought sensitivity of yields at the field scale.

  5. A USA-Africa collaborative strategy for identifying, characterizing, and developing maize germplasm with resistance to aflatoxin contamination.

    PubMed

    Menkir, Abebe; Brown, Robert L; Bandyopadhyay, Ranajit; Chen, Zhi-Yuan; Cleveland, Thomas E

    2006-09-01

    Aflatoxin contamination of maize by Aspergillus flavus poses serious potential economic losses in the US and health hazards to humans, particularly in West Africa. The Southern Regional Research Center of the United States Department of Agriculture, Agricultural Research Service (USDA-ARS-SRRC) and the International Institute of Tropical Agriculture (IITA) initiated a collaborative breeding project to develop maize germplasm with resistance to aflatoxin accumulation. Resistant genotypes from the US and selected inbred lines from IITA were used to generate backcrosses with 75% US germplasm and F(1) crosses with 50% IITA and 50% US germplasm. A total of 65 S(4) lines were developed from the backcross populations and 144 S(4) lines were derived from the F(1) crosses. These lines were separated into groups and screened in SRRC laboratory using a kernel-screening assay. Significant differences in aflatoxin production were detected among the lines within each group. Several promising S(4) lines with aflatoxin values significantly lower than their respective US resistant recurrent parent or their elite tropical inbred parent were selected for resistance-confirmation tests. We found pairs of S(4) lines with 75-94% common genetic backgrounds differing significantly in aflatoxin accumulation. These pairs of lines are currently being used for proteome analysis to identify resistance-associated proteins and the corresponding genes underlying resistance to aflatoxin accumulation. Following confirmation tests in the laboratory, lines with consistently low aflatoxin levels will be inoculated with A. flavus in the field in Nigeria to identify lines resistant to strains specific to both US and West Africa. Maize inbred lines with desirable agronomic traits and low levels of aflatoxin in the field would be released as sources of genes for resistance to aflatoxin production. PMID:16944289

  6. Rapid decomposition of maize detritus in agricultural headwater streams.

    PubMed

    Griffiths, Natalie A; Tank, Jennifer L; Royer, Todd V; Rosi-Marshall, Emma J; Whiles, Matt R; Chambers, Catherine P; Frauendorf, Therese C; Evans-White, Michelle A

    2009-01-01

    Headwater streams draining agricultural landscapes receive maize leaves (Zea mays L.) via wind and surface runoff, yet the contribution of maize detritus to organic-matter processing in agricultural streams is largely unknown. We quantified decomposition and microbial respiration rates on conventional (non-Bt) and genetically engineered (Bt) maize in three low-order agricultural streams in northwestern Indiana, USA. We also examined how substrate quality and in-stream nutrient concentrations influenced microbial respiration on maize by comparing respiration on maize and red maple leaves (Acer rubrum) in three nutrient-rich agricultural streams and three low-nutrient forested streams. We found significantly higher rates of microbial respiration on maize vs. red maple leaves and higher rates in agricultural vs. forested streams. Thus both the elevated nutrient status of agricultural streams and the lability of maize detritus (e.g., low carbon-to-nitrogen ratio and low lignin content) result in a rapid incorporation of maize leaves into the aquatic microbial food web. We found that Bt maize had a faster decomposition rate than non-Bt maize, while microbial respiration rates did not differ between Bt and non-Bt maize. Decomposition rates were not negatively affected by genetic engineering, perhaps because the Bt toxin does not adversely affect the aquatic microbial assemblage involved in maize decomposition. Additionally, shredding caddisflies, which are known to have suppressed growth rates when fed Bt maize, were depauperate in these agricultural streams, and likely did not play a major role in maize decomposition. Overall, the conversion of native vegetation to row-crop agriculture appears to have altered the quantity, quality, and predictability of allochthonous carbon inputs to headwater streams, with unexplored effects on stream ecosystem structure and function. PMID:19323178

  7. Maize growth promotion by inoculation with Azospirillum brasilense and metabolites of Rhizobium tropici enriched on lipo-chitooligosaccharides (LCOs).

    PubMed

    Marks, Bettina Berquó; Megías, Manuel; Ollero, Francisco Javier; Nogueira, Marco Antonio; Araujo, Ricardo Silva; Hungria, Mariangela

    2015-12-01

    There is an increasing interest in the development and use of inoculants carrying plant growth-promoting bacteria (PGPB) in crops of agronomic interest. The great majority of the inoculants commercialized worldwide contain rhizobia for legume crops, but the use of PGPB as Azospirillum spp. for non-legume is expanding, as well as of inoculants combining microorganisms and microbial metabolites. In this study we evaluated the effects of inoculants containing Azospirillum brasilense with or without metabolites of Rhizobium tropici strain CIAT 899 highly enriched in lipo-chitooligosaccharides (LCOs) in six field experiments performed for three summer crop seasons in Brazil with maize (Zea mays L.). Inoculants and metabolites were applied either at sowing by seed inoculation, or by leaf spray at the V3 stage of plant growth. Improvement in shoot dry weight (SDW) and total N accumulated in shoots (TNS) by single, but especially by dual inoculation was observed in some of the experiments. Statistically significant increases in grain yield in relation to the non-inoculated control were observed in five out of six experiments when maize was inoculated with Azospirillum supplied with enriched metabolites of R. tropici applied by seed or leaf spray inoculation. The results give strength to the development of a new generation of inoculants carrying microorganisms and microbial molecules.

  8. Maize growth promotion by inoculation with Azospirillum brasilense and metabolites of Rhizobium tropici enriched on lipo-chitooligosaccharides (LCOs).

    PubMed

    Marks, Bettina Berquó; Megías, Manuel; Ollero, Francisco Javier; Nogueira, Marco Antonio; Araujo, Ricardo Silva; Hungria, Mariangela

    2015-12-01

    There is an increasing interest in the development and use of inoculants carrying plant growth-promoting bacteria (PGPB) in crops of agronomic interest. The great majority of the inoculants commercialized worldwide contain rhizobia for legume crops, but the use of PGPB as Azospirillum spp. for non-legume is expanding, as well as of inoculants combining microorganisms and microbial metabolites. In this study we evaluated the effects of inoculants containing Azospirillum brasilense with or without metabolites of Rhizobium tropici strain CIAT 899 highly enriched in lipo-chitooligosaccharides (LCOs) in six field experiments performed for three summer crop seasons in Brazil with maize (Zea mays L.). Inoculants and metabolites were applied either at sowing by seed inoculation, or by leaf spray at the V3 stage of plant growth. Improvement in shoot dry weight (SDW) and total N accumulated in shoots (TNS) by single, but especially by dual inoculation was observed in some of the experiments. Statistically significant increases in grain yield in relation to the non-inoculated control were observed in five out of six experiments when maize was inoculated with Azospirillum supplied with enriched metabolites of R. tropici applied by seed or leaf spray inoculation. The results give strength to the development of a new generation of inoculants carrying microorganisms and microbial molecules. PMID:26567001

  9. Control of virus diseases in maize.

    PubMed

    Redinbaugh, Margaret G; Zambrano, José L

    2014-01-01

    Diseases caused by viruses are found throughout the maize-growing regions of the world and can cause significant losses for producers. In this review, virus diseases of maize and the pathogens that cause them are discussed. Factors leading to the spread of disease and measures for disease control are reviewed, as is our current knowledge of the genetics of virus resistance in this important crop. PMID:25410107

  10. Prospects for reducing fumonisin contamination of maize through genetic modification.

    PubMed Central

    Duvick, J

    2001-01-01

    Fumonisins (FB) are mycotoxins found in (italic)Fusarium verticillioides-infected maize grain worldwide. Attention has focused on FBs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. FBs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. Among the strategies for reducing risk of FB contamination in maize supplied to the market, development and deployment of Fusarium ear mold-resistant maize germplasm is a high priority. Breeding for increased ear mold tolerance and reduced mycotoxin levels is being practiced today in both commercial and public programs, but the amount of resistance achievable may be limited due to complicated genetics and/or linkage to undesirable agronomic traits. Molecular markers can be employed to speed up the incorporation of chromosomal regions that have a quantitative effect on resistance (quantitative trait loci). Transgenic approaches to ear mold/mycotoxin resistance are now feasible as well. These potentially include genetically enhanced resistance to insect feeding, increased fungal resistance, and detoxification/prevention of mycotoxins in the grain. An example of the first of these approaches is already on the market, namely transgenic maize expressing Bacillus thuringiensis (Bt) toxin, targeted to the European corn borer. Some Bt maize hybrids have the potential to reduce FB levels in field-harvested grain, presumably through reduced feeding of Bt-susceptible insects in ear tissues. However, improved ear mold resistance per se is still an important goal, as the plant will still be vulnerable to noninsect routes of entry to (italic)Fusarium. A second approach, transgene-mediated control of the ability of Fusarium to infect and colonize the ear, could potentially be achieved through overexpression of specific antifungal proteins and metabolites, or enhancement of the plant's own

  11. Prospects for reducing fumonisin contamination of maize through genetic modification.

    PubMed

    Duvick, J

    2001-05-01

    Fumonisins (FB) are mycotoxins found in (italic)Fusarium verticillioides-infected maize grain worldwide. Attention has focused on FBs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. FBs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. Among the strategies for reducing risk of FB contamination in maize supplied to the market, development and deployment of Fusarium ear mold-resistant maize germplasm is a high priority. Breeding for increased ear mold tolerance and reduced mycotoxin levels is being practiced today in both commercial and public programs, but the amount of resistance achievable may be limited due to complicated genetics and/or linkage to undesirable agronomic traits. Molecular markers can be employed to speed up the incorporation of chromosomal regions that have a quantitative effect on resistance (quantitative trait loci). Transgenic approaches to ear mold/mycotoxin resistance are now feasible as well. These potentially include genetically enhanced resistance to insect feeding, increased fungal resistance, and detoxification/prevention of mycotoxins in the grain. An example of the first of these approaches is already on the market, namely transgenic maize expressing Bacillus thuringiensis (Bt) toxin, targeted to the European corn borer. Some Bt maize hybrids have the potential to reduce FB levels in field-harvested grain, presumably through reduced feeding of Bt-susceptible insects in ear tissues. However, improved ear mold resistance per se is still an important goal, as the plant will still be vulnerable to noninsect routes of entry to (italic)Fusarium. A second approach, transgene-mediated control of the ability of Fusarium to infect and colonize the ear, could potentially be achieved through overexpression of specific antifungal proteins and metabolites, or enhancement of the plant's own

  12. A Survey of Fertilizer Dealers: I. Sources of Agronomic Training.

    ERIC Educational Resources Information Center

    Schmitt, M. A.

    1988-01-01

    Reports on a survey of fertilizer dealers which was conducted to: assess where and from whom local fertilizer dealers obtain agronomic training; evaluate the effectiveness of various dealer training; and determine the needs and objectives of future training programs. (TW)

  13. A Survey of Fertilizer Dealers: II. Sources of Agronomic Information.

    ERIC Educational Resources Information Center

    Schmitt, M. A.

    1988-01-01

    Reports on a survey of fertilizer dealers that was conducted to assess how the dealers were obtaining their agronomic information, aside from formal training sessions, and determine if these sources of information were satisfactory in fulfilling the dealers' needs. (TW)

  14. Integrating Agronomic Principles with Management Experience in Introductory Agronomy.

    ERIC Educational Resources Information Center

    Vorst, J. J.

    1989-01-01

    Explains the use of a cropping systems project to teach agronomic principles and crop management techniques, and to enhance communication skills. Provides a sample progress report instructions sheet which was used for the project. (Author/RT)

  15. Effect of farm yard manure on chemical fractionation of cadmium and its bio-availability to maize crop grown on sewage irrigated coarse textured soil.

    PubMed

    Khurana, M P S; Kansal, B D

    2014-03-01

    Cadmium is a potentially toxic heavy metal that enters food chain from the soil through various anthropogenic sources. Availability of metal ions in contaminated soils can be reduced by the addition of organic amendments. In this study, effect of organic matter -farm yard manure (FYM) amendment on fractionation and availability of Cd to maize was evaluated. A green house experiment was conducted to determine the toxicity and uptake of Cd by maize in sandy loam soil with and without organic matter. Four levels of Cd (0, 10, 20 and 40 mg kg(-1) soil) and two levels of FYM (0 and 20 tonnes ha(-1)) with three replication in a completely randomized factorial design. Concentration of Cd in maize increased with increasing rate of Cd application. Application of organic matter increased the dry matter yield of maize while reduced the uptake of metal. All the fractions exhibited increase with Cd rates. The addition of organic amendment declined significantly the concentration of water soluble and exchangeable Cd, but increased the amounts of these metals into less mobile fractions (Fe/Mn oxide, organic matter and residual). Dominance of insoluble forms of Cd after the application of organic amendments may be ascribed to the increases of soil OM, pH, EC and available P contents which caused transformation or redistribution of the sorbed phases. This resulted in increasing Cd retention in the more persistent fractions with application of FYM at the expense of reductions in the loosely bound fractions. Thus FYM appears to be agronomically feasible way to off set the adverse effect of Cd toxicity.

  16. Genetic and association mapping study of wheat agronomic traits under contrasting water regimes.

    PubMed

    Dodig, Dejan; Zoric, Miroslav; Kobiljski, Borislav; Savic, Jasna; Kandic, Vesna; Quarrie, Steve; Barnes, Jeremy

    2012-01-01

    Genetic analyses and association mapping were performed on a winter wheat core collection of 96 accessions sampled from a variety of geographic origins. Twenty-four agronomic traits were evaluated over 3 years under fully irrigated, rainfed and drought treatments. Grain yield was the most sensitive trait to water deficit and was highly correlated with above-ground biomass per plant and number of kernels per m(2). The germplasm was structured into four subpopulations. The association of 46 SSR loci distributed throughout the wheat genome with yield and agronomic traits was analyzed using a general linear model, where subpopulation information was used to control false-positive or spurious marker-trait associations (MTAs). A total of 26, 21 and 29 significant (P < 0.001) MTAs were identified in irrigated, rainfed and drought treatments, respectively. The marker effects ranged from 14.0 to 50.8%. Combined across all treatments, 34 significant (P < 0.001) MTAs were identified with nine markers, and R(2) ranged from 14.5 to 50.2%. Marker psp3200 (6DS) and particularly gwm484 (2DS) were associated with many significant MTAs in each treatment and explained the greatest proportion of phenotypic variation. Although we were not able to recognize any marker related to grain yield under drought stress, a number of MTAs associated with developmental and agronomic traits highly correlated with grain yield under drought were identified.

  17. Is the basal area of maize internodes involved in borer resistance?

    PubMed Central

    2011-01-01

    Background To elucidate the role of the length of the internode basal ring (LIBR) in resistance to the Mediterranean corn borer (MCB), we carried out a divergent selection program to modify the LIBR using two maize synthetic varieties (EPS20 and EPS21), each with a different genetic background. We investigated the biochemical mechanisms underlying the relationship between the LIBR and borer resistance. Selection to lengthen or shorten the LIBR was achieved for each synthetic variety. The resulting plants were analyzed to determine their LIBR response, growth, yield, and borer resistance. Results In the synthetic variety EPS20 (Reid germplasm), reduction of the LIBR improved resistance against the MCB. The LIBR selection was also effective in the synthetic variety EPS21 (non-Reid germplasm), although there was no relationship detected between the LIBR and MCB resistance. The LIBR did not show correlations with agronomic traits such as plant height and yield. Compared with upper sections, the internode basal ring area contained lower concentrations of cell wall components such as acid detergent fiber (ADF), acid detergent lignin (ADL), and diferulates. In addition, some residual 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3-(4H)-one (DIMBOA), a natural antibiotic compound, was detected in the basal area at 30 days after silking. Conclusion We analyzed maize selections to determine whether the basal area of maize internodes is involved in borer resistance. The structural reinforcement of the cell walls was the most significant trait in the relationship between the LIBR and borer resistance. Lower contents of ADF and ADL in the rind of the basal section facilitated the entry of larvae in this area in both synthetic varieties, while lower concentrations of diferulates in the pith basal section of EPS20 facilitated larval feeding inside the stem. The higher concentrations of DIMBOA may have contributed to the lack of correlation between the LIBR and borer resistance in

  18. Sugarcane Functional Genomics: Gene Discovery for Agronomic Trait Development

    PubMed Central

    Menossi, M.; Silva-Filho, M. C.; Vincentz, M.; Van-Sluys, M.-A.; Souza, G. M.

    2008-01-01

    Sugarcane is a highly productive crop used for centuries as the main source of sugar and recently to produce ethanol, a renewable bio-fuel energy source. There is increased interest in this crop due to the impending need to decrease fossil fuel usage. Sugarcane has a highly polyploid genome. Expressed sequence tag (EST) sequencing has significantly contributed to gene discovery and expression studies used to associate function with sugarcane genes. A significant amount of data exists on regulatory events controlling responses to herbivory, drought, and phosphate deficiency, which cause important constraints on yield and on endophytic bacteria, which are highly beneficial. The means to reduce drought, phosphate deficiency, and herbivory by the sugarcane borer have a negative impact on the environment. Improved tolerance for these constraints is being sought. Sugarcane's ability to accumulate sucrose up to 16% of its culm dry weight is a challenge for genetic manipulation. Genome-based technology such as cDNA microarray data indicates genes associated with sugar content that may be used to develop new varieties improved for sucrose content or for traits that restrict the expansion of the cultivated land. The genes can also be used as molecular markers of agronomic traits in traditional breeding programs. PMID:18273390

  19. MaizeGDB, the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

  20. Population structure and association mapping of yield contributing agronomic traits in foxtail millet.

    PubMed

    Gupta, Sarika; Kumari, Kajal; Muthamilarasan, Mehanathan; Parida, Swarup Kumar; Prasad, Manoj

    2014-06-01

    Association analyses accounting for population structure and relative kinship identified eight SSR markers ( p < 0.01) showing significant association ( R (2) = 18 %) with nine agronomic traits in foxtail millet. Association mapping is an efficient tool for identifying genes regulating complex traits. Although association mapping using genomic simple sequence repeat (SSR) markers has been successfully demonstrated in many agronomically important crops, very few reports are available on marker-trait association analysis in foxtail millet. In the present study, 184 foxtail millet accessions from diverse geographical locations were genotyped using 50 SSR markers representing the nine chromosomes of foxtail millet. The genetic diversity within these accessions was examined using a genetic distance-based and a general model-based clustering method. The model-based analysis using 50 SSR markers identified an underlying population structure comprising five sub-populations which corresponded well with distance-based groupings. The phenotyping of plants was carried out in the field for three consecutive years for 20 yield contributing agronomic traits. The linkage disequilibrium analysis considering population structure and relative kinship identified eight SSR markers (p < 0.01) on different chromosomes showing significant association (R (2) = 18 %) with nine agronomic traits. Four of these markers were associated with multiple traits. The integration of genetic and physical map information of eight SSR markers with their functional annotation revealed strong association of two markers encoding for phospholipid acyltransferase and ubiquitin carboxyl-terminal hydrolase located on the same chromosome (5) with flag leaf width and grain yield, respectively. Our findings on association mapping is the first report on Indian foxtail millet germplasm and this could be effectively applied in foxtail millet breeding to further uncover marker-trait associations with a large number of

  1. Quantitative genetic analysis of agronomic and morphological traits in sorghum, Sorghum bicolor

    PubMed Central

    Mohammed, Riyazaddin; Are, Ashok K.; Bhavanasi, Ramaiah; Munghate, Rajendra S.; Kavi Kishor, Polavarapu B.; Sharma, Hari C.

    2015-01-01

    The productivity in sorghum is low, owing to various biotic and abiotic constraints. Combining insect resistance with desirable agronomic and morphological traits is important to increase sorghum productivity. Therefore, it is important to understand the variability for various agronomic traits, their heritabilities and nature of gene action to develop appropriate strategies for crop improvement. Therefore, a full diallel set of 10 parents and their 90 crosses including reciprocals were evaluated in replicated trials during the 2013–14 rainy and postrainy seasons. The crosses between the parents with early- and late-flowering flowered early, indicating dominance of earliness for anthesis in the test material used. Association between the shoot fly resistance, morphological, and agronomic traits suggested complex interactions between shoot fly resistance and morphological traits. Significance of the mean sum of squares for GCA (general combining ability) and SCA (specific combining ability) of all the studied traits suggested the importance of both additive and non-additive components in inheritance of these traits. The GCA/SCA, and the predictability ratios indicated predominance of additive gene effects for majority of the traits studied. High broad-sense and narrow-sense heritability estimates were observed for most of the morphological and agronomic traits. The significance of reciprocal combining ability effects for days to 50% flowering, plant height and 100 seed weight, suggested maternal effects for inheritance of these traits. Plant height and grain yield across seasons, days to 50% flowering, inflorescence exsertion, and panicle shape in the postrainy season showed greater specific combining ability variance, indicating the predominance of non-additive type of gene action/epistatic interactions in controlling the expression of these traits. Additive gene action in the rainy season, and dominance in the postrainy season for days to 50% flowering and plant

  2. Quantitative genetic analysis of agronomic and morphological traits in sorghum, Sorghum bicolor.

    PubMed

    Mohammed, Riyazaddin; Are, Ashok K; Bhavanasi, Ramaiah; Munghate, Rajendra S; Kavi Kishor, Polavarapu B; Sharma, Hari C

    2015-01-01

    The productivity in sorghum is low, owing to various biotic and abiotic constraints. Combining insect resistance with desirable agronomic and morphological traits is important to increase sorghum productivity. Therefore, it is important to understand the variability for various agronomic traits, their heritabilities and nature of gene action to develop appropriate strategies for crop improvement. Therefore, a full diallel set of 10 parents and their 90 crosses including reciprocals were evaluated in replicated trials during the 2013-14 rainy and postrainy seasons. The crosses between the parents with early- and late-flowering flowered early, indicating dominance of earliness for anthesis in the test material used. Association between the shoot fly resistance, morphological, and agronomic traits suggested complex interactions between shoot fly resistance and morphological traits. Significance of the mean sum of squares for GCA (general combining ability) and SCA (specific combining ability) of all the studied traits suggested the importance of both additive and non-additive components in inheritance of these traits. The GCA/SCA, and the predictability ratios indicated predominance of additive gene effects for majority of the traits studied. High broad-sense and narrow-sense heritability estimates were observed for most of the morphological and agronomic traits. The significance of reciprocal combining ability effects for days to 50% flowering, plant height and 100 seed weight, suggested maternal effects for inheritance of these traits. Plant height and grain yield across seasons, days to 50% flowering, inflorescence exsertion, and panicle shape in the postrainy season showed greater specific combining ability variance, indicating the predominance of non-additive type of gene action/epistatic interactions in controlling the expression of these traits. Additive gene action in the rainy season, and dominance in the postrainy season for days to 50% flowering and plant

  3. A Dutch field survey on fungal infection and mycotoxin concentrations in maize.

    PubMed

    Van Asselt, E D; Azambuja, W; Moretti, A; Kastelein, P; De Rijk, T C; Stratakou, I; Van Der Fels-Klerx, H J

    2012-01-01

    Mycotoxins are secondary metabolites produced by fungi that can cause adverse health effects. Due to climate change, temperatures are expected to rise and changes in rainfall patterns are foreseen. These developments may increase fungal occurrence and mycotoxin concentrations in maize. It is therefore useful to monitor mycotoxin levels in maize and record the accompanying agronomic factors and weather parameters. This paper describes a field survey in the Netherlands in which information on soil, cultivar, green manure, tillage as well as sowing, emergence, flowering and harvest dates of silage maize were collected from 148 growers. A small number of these growers (42 in total) were visited to collect maize samples revealing that 50% of the samples were contaminated with Fusarium species and mycotoxins were detected in 25% of the samples. The Fusarium species that was most commonly found was F. crookwellense followed by F. graminearum, F. culmorum, F. sporotrichiodes and F. equiseti. In total 31 mycotoxins were analysed. The predominant mycotoxins present were (sum of 3 and 15)-acetyl-DON and nivalenol; other mycotoxins found were alternariol, beauvericin, deoxynivalenol, diacetoxyscirpenol, moniliformin and zearalenone. Nivalenol was present in concentrations up to 1670 µg kg⁻¹ and acetylated DON was usually present at higher concentrations than DON. Statistical analysis of the current data showed no correlation between mycotoxins present and agronomic factors recorded. Field studies as described in this paper are useful and need to be continued in the future in order to observe trends in mycotoxin occurrence.

  4. Genetic diversity analysis in Tunisian perennial ryegrass germplasm as estimated by RAPD, ISSR, and morpho-agronomical markers.

    PubMed

    Ghariani, S; Elazreg, H; Chtourou-Ghorbel, N; Chakroun, M; Trifi-Farah, N

    2015-01-01

    Tunisia is rich in diverse forage and pasture species including perennial ryegrass. In order to enhance forage production and improve agronomic performance of this local germplasm, a molecular analysis was undertaken. Random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR) and morpho-agronomical traits markers were used for genetic diversity estimation of ryegrass germplasm after screening 20 spontaneous accessions, including a local and an introduced cultivars. Same mean polymorphism information content values were obtained (0.37) for RAPD and ISSR suggesting that both marker systems were equally effective in determining polymorphisms. The average pairwise genetic distance values were 0.57 (morpho-agronomical traits), 0.68 (RAPD), and 0.51 (ISSR) markers data sets. A higher Shannon diversity index was obtained with ISSR marker (0.57) than for RAPD (0.54) and morpho-agronomical traits (0.36). The Mantel test based on genetic distances of a combination of molecular markers and morpho-agronomical data exhibited a significant correlation between RAPD and ISSR data, suggesting that the use of a combination of molecular techniques was a highly efficient method of estimating genetic variability levels among Tunisian ryegrass germplasm. In summary, results showed that combining molecular and morpho-agronomical markers is an efficient way in assessing the genetic variability among Tunisian ryegrass genotypes. In addition, the combined analysis provided an exhaustive coverage for the analyzed diversity and helped us to identify suitable accessions showed by Beja and Jendouba localities, which present large similarities with cultivated forms and can be exploited for designing breeding programmes, conservation of germplasm and management of ryegrass genetic resources. PMID:26782500

  5. Genetic diversity analysis in Tunisian perennial ryegrass germplasm as estimated by RAPD, ISSR, and morpho-agronomical markers.

    PubMed

    Ghariani, S; Elazreg, H; Chtourou-Ghorbel, N; Chakroun, M; Trifi-Farah, N

    2015-12-28

    Tunisia is rich in diverse forage and pasture species including perennial ryegrass. In order to enhance forage production and improve agronomic performance of this local germplasm, a molecular analysis was undertaken. Random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR) and morpho-agronomical traits markers were used for genetic diversity estimation of ryegrass germplasm after screening 20 spontaneous accessions, including a local and an introduced cultivars. Same mean polymorphism information content values were obtained (0.37) for RAPD and ISSR suggesting that both marker systems were equally effective in determining polymorphisms. The average pairwise genetic distance values were 0.57 (morpho-agronomical traits), 0.68 (RAPD), and 0.51 (ISSR) markers data sets. A higher Shannon diversity index was obtained with ISSR marker (0.57) than for RAPD (0.54) and morpho-agronomical traits (0.36). The Mantel test based on genetic distances of a combination of molecular markers and morpho-agronomical data exhibited a significant correlation between RAPD and ISSR data, suggesting that the use of a combination of molecular techniques was a highly efficient method of estimating genetic variability levels among Tunisian ryegrass germplasm. In summary, results showed that combining molecular and morpho-agronomical markers is an efficient way in assessing the genetic variability among Tunisian ryegrass genotypes. In addition, the combined analysis provided an exhaustive coverage for the analyzed diversity and helped us to identify suitable accessions showed by Beja and Jendouba localities, which present large similarities with cultivated forms and can be exploited for designing breeding programmes, conservation of germplasm and management of ryegrass genetic resources.

  6. Maize Genetic Resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the resources held at the Maize Genetics Cooperation • Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

  7. MAIZE ALLELIC DIVERSITY PROJECT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the estimated 250-300 races of maize, only 24 races are represented in materials utilized by the Germplasm Enhancement of Maize (GEM) project, a collaborative effort between USDA-ARS and public and private sector research scientists. This is largely a result of poor performance of many races in ...

  8. Transmission of maize chromosome 9 rearrangements in oat-maize radiation hybrids.

    PubMed

    Vales, M Isabel; Riera-Lizarazu, Oscar; Rines, Howard W; Phillips, Ronald L

    2004-12-01

    Oat-maize radiation hybrids are oat (Avena sativa L.) plants carrying radiation-induced subchromosome fragments of a given maize (Zea mays L.) chromosome. Since first-generation radiation hybrids contain various maize chromosome rearrangements in a hemizygous condition, variation might be expected in the transmission of these rearrangements to subsequent generations. The transmission and integrity of maize chromosome 9 rearrangements were evaluated in progenies of 30 oat-maize radiation hybrids by using a series of DNA-based markers and by genomic in situ hybridization. Maize chromosome 9 rearrangements were reisolated by self-fertilization in 24 of the 30 radiation hybrid lineages. Normal and deleted versions of maize chromosome 9 were transmitted at similar frequencies of 9.1% and 7.6%, respectively, while intergenomic translocations were transmitted at a significantly higher frequency of 47.6%. Most lines (93%) that inherited a rearrangement had it in the hemizygous condition. Lines with a rearrangement in the homozygous state (7%) were only identified in lineages with intergenomic translocations. Homozygous lines are more desirable from the perspective of stock maintenance, since they may stably transmit a given rearrangement to a subsequent generation. However, their isolation is not strictly required, since hemizygous lines can also be used for genome mapping studies.

  9. Fast-flowering mini-maize: seed to seed in 60 days

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generatio...

  10. Potentials of engineered nanoparticles as fertilizers for increasing agronomic productions.

    PubMed

    Liu, Ruiqiang; Lal, Rattan

    2015-05-01

    Development and application of new types of fertilizers using innovative nanotechnology are one of the potentially effective options of significantly enhancing the global agricultural productions needed to meet the future demands of the growing population. Indeed, the review of available literature indicates that some engineered nanomaterials can enhance plant-growth in certain concentration ranges and could be used as nanofertilizers in agriculture to increase agronomic yields of crops and/or minimize environmental pollution. This article summarizes this type of nanomaterials under four categories: macronutrient nanofertilizers, micronutrient nanofertilizers, nutrient-loaded nanofertilizers, and plant-growth-enhancing nanomaterials. Each category is discussed respectively with reference to nanomaterials' chemical composition, particle size, concentrations applied, benefited plant species, plant incubation methods, and plant-growth enhancement aspects and the rates. The importance, research directions, and research requirements of each nanofertilizer category for achieving sustainable agriculture are also specifically examined. Finally, this review suggests that development of N and P macronutrient nanofertilizers is a high research and development priority both for food production and environmental protection.

  11. Agronomic characteristics of five different urban waste digestates.

    PubMed

    Tampio, Elina; Salo, Tapio; Rintala, Jukka

    2016-03-15

    The use of digestate in agriculture is an efficient way to recycle materials and to decrease the use of mineral fertilizers. The agronomic characteristics of the digestates can promote plant growth and soil properties after digestate fertilization but also harmful effects can arise due to digestate quality, e.g. pH, organic matter and heavy metal content. The objective of this study was to evaluate the differences and similarities in agronomic characteristics and the value of five urban waste digestates from different biogas plants treating either food waste, organic fraction of organic solid waste or a mixture of waste-activated sludge and vegetable waste. The digestate agronomic characteristics were studied with chemical analyses and the availability of nutrients was also assessed with growth experiments and soil mineralization tests. All studied urban digestates produced 5-30% higher ryegrass yields compared to a control mineral fertilizer with a similar inorganic nitrogen concentration, while the feedstock source affected the agronomic value. Food waste and organic fraction of municipal solid waste digestates were characterized by high agronomic value due to the availability of nutrients and low heavy metal load. Waste-activated sludge as part of the feedstock mixture, however, increased the heavy metal content and reduced nitrogen availability to the plant, thus reducing the fertilizer value of the digestate. PMID:26773433

  12. Agronomic characteristics of five different urban waste digestates.

    PubMed

    Tampio, Elina; Salo, Tapio; Rintala, Jukka

    2016-03-15

    The use of digestate in agriculture is an efficient way to recycle materials and to decrease the use of mineral fertilizers. The agronomic characteristics of the digestates can promote plant growth and soil properties after digestate fertilization but also harmful effects can arise due to digestate quality, e.g. pH, organic matter and heavy metal content. The objective of this study was to evaluate the differences and similarities in agronomic characteristics and the value of five urban waste digestates from different biogas plants treating either food waste, organic fraction of organic solid waste or a mixture of waste-activated sludge and vegetable waste. The digestate agronomic characteristics were studied with chemical analyses and the availability of nutrients was also assessed with growth experiments and soil mineralization tests. All studied urban digestates produced 5-30% higher ryegrass yields compared to a control mineral fertilizer with a similar inorganic nitrogen concentration, while the feedstock source affected the agronomic value. Food waste and organic fraction of municipal solid waste digestates were characterized by high agronomic value due to the availability of nutrients and low heavy metal load. Waste-activated sludge as part of the feedstock mixture, however, increased the heavy metal content and reduced nitrogen availability to the plant, thus reducing the fertilizer value of the digestate.

  13. Satellite-based studies of maize yield spatial variations and their causes in China

    NASA Astrophysics Data System (ADS)

    Zhao, Y.

    2013-12-01

    Maize production in China has been expanding significantly in the past two decades, but yield has become relatively stagnant in the past few years, and needs to be improved to meet increasing demand. Multiple studies found that the gap between potential and actual yield of maize is as large as 40% to 60% of yield potential. Although a few major causes of yield gap have been qualitatively identified with surveys, there has not been spatial analysis aimed at quantifying relative importance of specific biophysical and socio-economic causes, information which would be useful for targeting interventions. This study analyzes the causes of yield variation at field and village level in Quzhou county of North China Plain (NCP). We combine remote sensing and crop modeling to estimate yields in 2009-2012, and identify fields that are consistently high or low yielding. To establish the relationship between yield and potential factors, we gather data on those factors through a household survey. We select targeted survey fields such that not only both extremes of yield distribution but also all soil texture categories in the county is covered. Our survey assesses management and biophysical factors as well as social factors such as farmers' access to agronomic knowledge, which is approximated by distance to the closest demonstration plot or 'Science and technology backyard'. Our survey covers 10 townships, 53 villages and 180 fields. Three to ten farmers are surveyed depending on the amount of variation present among sub pixels of each field. According to survey results, we extract the amount of variation within as well as between villages and or soil type. The higher within village or within field variation, the higher importance of management factors. Factors such as soil type and access to knowledge are more represented by between village variation. Through regression and analysis of variance, we gain more quantitative and thorough understanding of causes to yield variation at

  14. Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

    PubMed

    Truter, J; Van Hamburg, H; Van Den Berg, J

    2014-02-01

    The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance.

  15. Large-scale evaluation of maize germplasm for low-phosphorus tolerance.

    PubMed

    Zhang, Hongwei; Xu, Ruineng; Xie, Chuanxiao; Huang, Changling; Liao, Hong; Xu, Yunbi; Wang, Jinxiang; Li, Wen-Xue

    2015-01-01

    Low-phosphorus (LP) stress is a global problem for maize production and has been exacerbated by breeding activities that have reduced the genetic diversity of maize. Although LP tolerance in maize has been previously evaluated, the evaluations were generally performed with only a small number of accessions or with samples collected from a limited area. In this research, 826 maize accessions (including 580 tropical/subtropical accessions and 246 temperate accessions) were evaluated for LP tolerance under field conditions in 2011 and 2012. Plant height (PH) and leaf number were measured at three growth stages. The normalized difference vegetation index (NDVI) and fresh ear weight (FEW) were also measured. Genetic correlation analysis revealed that FEW and NDVI were strongly correlated with PH, especially at later stages. LP-tolerant and -sensitive accessions were selected based on the relative trait values of all traits using principal component analysis, and all the 14 traits of the tolerant maize accessions showed less reduction than the sensitive accessions under LP conditions. LP tolerance was strongly correlated with agronomic performance under LP stress conditions, and both criteria could be used for genetic analysis and breeding of LP tolerance. Temperate accessions showed slightly better LP tolerance than tropical/subtropical ones, although more tolerant accessions were identified from tropical/subtropical accessions, which could be contributed by their larger sample size. This large-scale evaluation provides useful information, LP-tolerant germplasm resources and evaluation protocol for genetic analysis and developing maize varieties for LP tolerance.

  16. Large-Scale Evaluation of Maize Germplasm for Low-Phosphorus Tolerance

    PubMed Central

    Zhang, Hongwei; Xu, Ruineng; Xie, Chuanxiao; Huang, Changling; Liao, Hong; Xu, Yunbi; Wang, Jinxiang; Li, Wen-Xue

    2015-01-01

    Low-phosphorus (LP) stress is a global problem for maize production and has been exacerbated by breeding activities that have reduced the genetic diversity of maize. Although LP tolerance in maize has been previously evaluated, the evaluations were generally performed with only a small number of accessions or with samples collected from a limited area. In this research, 826 maize accessions (including 580 tropical/subtropical accessions and 246 temperate accessions) were evaluated for LP tolerance under field conditions in 2011 and 2012. Plant height (PH) and leaf number were measured at three growth stages. The normalized difference vegetation index (NDVI) and fresh ear weight (FEW) were also measured. Genetic correlation analysis revealed that FEW and NDVI were strongly correlated with PH, especially at later stages. LP-tolerant and -sensitive accessions were selected based on the relative trait values of all traits using principal component analysis, and all the 14 traits of the tolerant maize accessions showed less reduction than the sensitive accessions under LP conditions. LP tolerance was strongly correlated with agronomic performance under LP stress conditions, and both criteria could be used for genetic analysis and breeding of LP tolerance. Temperate accessions showed slightly better LP tolerance than tropical/subtropical ones, although more tolerant accessions were identified from tropical/subtropical accessions, which could be contributed by their larger sample size. This large-scale evaluation provides useful information, LP-tolerant germplasm resources and evaluation protocol for genetic analysis and developing maize varieties for LP tolerance. PMID:25938641

  17. Yield Potential of Soil Water and Its Sustainability for Dryland Spring Maize with Plastic Film Mulch on the Loess Plateau

    NASA Astrophysics Data System (ADS)

    Lin, Wen; Liu, Wenzhao

    2016-04-01

    Plastic film mulch(PM) is an agronomic measure widely used in the dryland spring maize production system on the Loess Plateau of China. The measure can greatly increase yield of dryland maize due to its significant effects on soil water conservation. Few researches have been done to investigate how the yield potential is impacted by PM. The yield-water use (ET) boundary equation raised by French and Schultz provides a simple approach to calculate crop water limited yield potential and gives a benchmark for farmers in managing their crops. However, method used in building the equation is somewhat arbitrary and has no strict principle, which leads to the uncertainty of equation when it is applied. Though using PM can increase crop yield, it increases soil temperature, promotes crop growth and increases the water transpired by crop, which further leads to high water consumption as compared with crops without PM. This means that PM may lead to the overuse of soil water and hence is unsustainable in a long run. This research is mainly focused on the yield potential and sustainability of PMing for spring maize on the Loess Plateau. A principle that may be utilized by any other researchers was proposed based on French & Schultz's boundary equation and on part of quantile regression theory. We used a data set built by collecting the experimental data from published papers and analyzed the water-limited yield potential of spring maize on the Loess Plateau. Moreover, maize yield and soil water dynamics under PM were investigated by a long-term site field experiment. Results show that on the Loess Plateau, the water limited yield potential can be calculated using the boundary equation y = 60.5×(x - 50), with a platform yield of 15954 kghm-2 after the water use exceeds 314 mm. Without PMing, the water limited yield potential can be estimated by the boundary equation y = 47.5×(x - 62.3) , with a platform yield of 12840 kghm-2 when the water use exceeds 325 mm, which

  18. The genetic architecture of maize height.

    PubMed

    Peiffer, Jason A; Romay, Maria C; Gore, Michael A; Flint-Garcia, Sherry A; Zhang, Zhiwu; Millard, Mark J; Gardner, Candice A C; McMullen, Michael D; Holland, James B; Bradbury, Peter J; Buckler, Edward S

    2014-04-01

    Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in >64,500 plots across 13 environments. These plots contained >7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be >90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of height variation. The effects of two tropical alleles at this QTL were independently validated by fine mapping in NIL families. Several significant associations found by GWAS colocalized with established height loci, including brassinosteroid-deficient dwarf1, dwarf plant1, and semi-dwarf2. GBLUP explained >80% of height variation in the panels and outperformed bootstrap aggregation of family-nested QTL models in evaluations of prediction accuracy. These results revealed maize height was under strong genetic control and had a highly polygenic genetic architecture. They also showed that multiple models of genetic architecture differing in polygenicity and effect sizes can plausibly explain a population's variation in maize height, but they may vary in predictive efficacy.

  19. Aflatoxin regulations in a network of global maize trade.

    PubMed

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1), B(2), G(1), and G(2)) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

  20. Aflatoxin regulations in a network of global maize trade.

    PubMed

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1), B(2), G(1), and G(2)) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. PMID:23049773

  1. Aflatoxin Regulations in a Network of Global Maize Trade

    PubMed Central

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000–2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B1, B2, G1, and G2) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. PMID:23049773

  2. Diversity characterization and association analysis of agronomic traits in a Chinese peanut (Arachis hypogaea L.) mini-core collection.

    PubMed

    Jiang, Huifang; Huang, Li; Ren, Xiaoping; Chen, Yuning; Zhou, Xiaojing; Xia, Youlin; Huang, Jiaquan; Lei, Yong; Yan, Liying; Wan, Liyun; Liao, Boshou

    2014-02-01

    Association mapping is a powerful approach for exploring the molecular basis of phenotypic variations in plants. A peanut (Arachis hypogaea L.) mini-core collection in China comprising 298 accessions was genotyped using 109 simple sequence repeat (SSR) markers, which identified 554 SSR alleles and phenotyped for 15 agronomic traits in three different environments, exhibiting abundant genetic and phenotypic diversity within the panel. A model-based structure analysis assigned all accessions to three groups. Most of the accessions had the relative kinship of less than 0.05, indicating that there were no or weak relationships between accessions of the mini-core collection. For 15 agronomic traits in the peanut panel, generally the Q + K model exhibited the best performance to eliminate the false associated positives compared to the Q model and the general linear model-simple model. In total, 89 SSR alleles were identified to be associated with 15 agronomic traits of three environments by the Q + K model-based association analysis. Of these, eight alleles were repeatedly detected in two or three environments, and 15 alleles were commonly detected to be associated with multiple agronomic traits. Simple sequence repeat allelic effects confirmed significant differences between different genotypes of these repeatedly detected markers. Our results demonstrate the great potential of integrating the association analysis and marker-assisted breeding by utilizing the peanut mini-core collection.

  3. Maize (Zea mays L.).

    PubMed

    Frame, Bronwyn; Warnberg, Katey; Main, Marcy; Wang, Kan

    2015-01-01

    Agrobacterium tumefaciens-mediated transformation is an effective method for introducing genes into maize. In this chapter, we describe a detailed protocol for genetic transformation of the maize genotype Hi II. Our starting plant material is immature embryos cocultivated with an Agrobacterium strain carrying a standard binary vector. In addition to step-by-step laboratory transformation procedures, we include extensive details in growing donor plants and caring for transgenic plants in the greenhouse.

  4. Biochar: A synthesis of its agronomic impact beyond carbon sequestration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar has been recently heralded as an amendment to revitalize degraded soils, improve soil carbon sequestration, increase agronomic productivity and enter into future carbon trading markets. However, scientific and economic technicalities may limit the ability of biochar to consistently deliver o...

  5. Agronomic performance of five banana cultivars under protected cultivation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Banana has been grown both in open-field and protected cultivation in Turkey. So far protected cultivation is very popular due to the high yield and quality. The objective of the study was to evaluate agronomic performance of five new banana cultivars under plastic greenhouse. ‘MA 13’, ‘Williams’, ‘...

  6. Data access and interchange in agronomic and natural resources management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Challenges related to agriculture and natural resource management have never been greater. Comprehensive agronomic and natural resources data relevant to climate change, food security, bioenergy, and sustainable water supply are rare and in demand. Data used for policy development must be rigorous...

  7. Genomic variation in maize: Annual and summary report, 1988

    SciTech Connect

    Rivin, C.J.

    1988-01-01

    We are interested in the molecular basis and biological significance of genomic diversity. Our laboratory has been studying genomic variation in maize and examples of rapidly occurring changes in maize DNA. To understand the mechanisms that generate and maintain variation, the author's lab has followed the reproducibility and stability of new repeated sequence multiplicities in succeeding generations, during plant development and in regenerated plants. We have also initiated studies of the Robertson's Mutator transposon system. These transposons have been shown to be quite variable in copy number in Mutator stocks of maize, but were reported to be absent in normal maize lines. We showed that sequences homologous to the transposon exist in a variety of forms in normal maize, including complete transposon structures. Results are discussed. 3 figs., 1 tab.

  8. Soil organic matter quality in intensive maize-based forage systems

    NASA Astrophysics Data System (ADS)

    Zavattaro, L.; Sacco, D.; Bertora, C.; Monaco, S.; Grignani, C.

    2009-04-01

    in the past years strongly dominated the soil response, whereas fresh applications of farmyard manure or slurry did not cause any significant difference on the timing and extent of net N mineralization in the weeks that followed fertilization. This evidence stresses one more the difference, in aim and results, that long-term agronomical studies exert with regards to those lasting few years.

  9. Agronomic Suitability of Bioenergy Crops in Mississippi

    SciTech Connect

    Lemus, Rocky; Baldwin, Brian; Lang, David

    2011-10-01

    ‚€Ã‚¢ How will these crops affect fertilizer use and water quality? • What kind of water management is needed to maintain a productive crop? The answers to these questions will help supporting institutions across the state to improve land assessment and agronomic management practices for biomass production. In the last decade, energy supply has become a worldwide problem. Bioenergy crops could supply energy in the future. Bioenergy crops are plants, usually perennial grasses and trees, that produce a lot of biomass that can be converted into energy. Bioenergy crops can be grown for two energy markets: power generation, such as heat and electricity, or liquid fuel, such as cellulosic ethanol. These resources could reduce petroleum dependency and greenhouse gas production. Woody plants and herbaceous warm-season grasses, such as switchgrass, giant miscanthus,energy cane, and high yielding sorghums, could be major sources of biomass in Mississippi.

  10. Diversity in global maize germplasm: characterization and utilization.

    PubMed

    Prasanna, B M

    2012-11-01

    Maize (Zea mays L.) is not only of worldwide importance as a food, feed and as a source of diverse industrially important products, but is also a model genetic organism with immense genetic diversity. Although it was first domesticated in Mexico, maize landraces are widely found across the continents. Several studies in Mexico and other countries highlighted the genetic variability in the maize germplasm. Applications of molecular markers, particularly in the last two decades, have led to new insights into the patterns of genetic diversity in maize globally, including landraces as well as wild relatives (especially teosintes) in Latin America, helping in tracking the migration routes of maize from the centers of origin, and understanding the fate of genetic diversity during maize domestication. The genome sequencing of B73 (a highly popular US Corn Belt inbred) and Palomero (a popcorn landrace in Mexico) in the recent years are important landmarks in maize research, with significant implications to our understanding of the maize genome organization and evolution. Next-generation sequencing and high-throughput genotyping platforms promise to further revolutionize our understanding of genetic diversity and for designing strategies to utilize the genomic information for maize improvement. However, the major limiting factor to exploit the genetic diversity in crops like maize is no longer genotyping, but high-throughput and precision phenotyping. There is an urgent need to establish a global phenotyping network for comprehensive and efficient characterization of maize germplasm for an array of target traits, particularly for biotic and abiotic stress tolerance and nutritional quality. 'Seeds of Discovery' (SeeD), a novel initiative by CIMMYT with financial support from the Mexican Government for generating international public goods, has initiated intensive exploration of phenotypic and molecular diversity of maize germplasm conserved in the CIMMYT Gene Bank; this is

  11. Evolution of US maize (Zea mays L.) root architectural and anatomical phenes over the past 100 years corresponds to increased tolerance of nitrogen stress.

    PubMed

    York, Larry M; Galindo-Castañeda, Tania; Schussler, Jeffrey R; Lynch, Jonathan P

    2015-04-01

    Increasing the nitrogen use efficiency of maize is an important goal for food security and agricultural sustainability. In the past 100 years, maize breeding has focused on yield and above-ground phenes. Over this period, maize cultivation has changed from low fertilizer inputs and low population densities to intensive fertilization and dense populations. The authors hypothesized that through indirect selection the maize root system has evolved phenotypes suited to more intense competition for nitrogen. Sixteen maize varieties representing commercially successful lines over the past century were planted at two nitrogen levels and three planting densities. Root systems of the most recent material were 7 º more shallow, had one less nodal root per whorl, had double the distance from nodal root emergence to lateral branching, and had 14% more metaxylem vessels, but total mextaxylem vessel area remained unchanged because individual metaxylem vessels had 12% less area. Plasticity was also observed in cortical phenes such as aerenchyma, which increased at greater population densities. Simulation modelling with SimRoot demonstrated that even these relatively small changes in root architecture and anatomy could increase maize shoot growth by 16% in a high density and high nitrogen environment. The authors concluded that evolution of maize root phenotypes over the past century is consistent with increasing nitrogen use efficiency. Introgression of more contrasting root phene states into the germplasm of elite maize and determination of the functional utility of these phene states in multiple agronomic conditions could contribute to future yield gains.

  12. Evolution of US maize (Zea mays L.) root architectural and anatomical phenes over the past 100 years corresponds to increased tolerance of nitrogen stress.

    PubMed

    York, Larry M; Galindo-Castañeda, Tania; Schussler, Jeffrey R; Lynch, Jonathan P

    2015-04-01

    Increasing the nitrogen use efficiency of maize is an important goal for food security and agricultural sustainability. In the past 100 years, maize breeding has focused on yield and above-ground phenes. Over this period, maize cultivation has changed from low fertilizer inputs and low population densities to intensive fertilization and dense populations. The authors hypothesized that through indirect selection the maize root system has evolved phenotypes suited to more intense competition for nitrogen. Sixteen maize varieties representing commercially successful lines over the past century were planted at two nitrogen levels and three planting densities. Root systems of the most recent material were 7 º more shallow, had one less nodal root per whorl, had double the distance from nodal root emergence to lateral branching, and had 14% more metaxylem vessels, but total mextaxylem vessel area remained unchanged because individual metaxylem vessels had 12% less area. Plasticity was also observed in cortical phenes such as aerenchyma, which increased at greater population densities. Simulation modelling with SimRoot demonstrated that even these relatively small changes in root architecture and anatomy could increase maize shoot growth by 16% in a high density and high nitrogen environment. The authors concluded that evolution of maize root phenotypes over the past century is consistent with increasing nitrogen use efficiency. Introgression of more contrasting root phene states into the germplasm of elite maize and determination of the functional utility of these phene states in multiple agronomic conditions could contribute to future yield gains. PMID:25795737

  13. Evolution of US maize (Zea mays L.) root architectural and anatomical phenes over the past 100 years corresponds to increased tolerance of nitrogen stress

    PubMed Central

    York, Larry M.; Galindo-Castañeda, Tania; Schussler, Jeffrey R.; Lynch, Jonathan P.

    2015-01-01

    Increasing the nitrogen use efficiency of maize is an important goal for food security and agricultural sustainability. In the past 100 years, maize breeding has focused on yield and above-ground phenes. Over this period, maize cultivation has changed from low fertilizer inputs and low population densities to intensive fertilization and dense populations. The authors hypothesized that through indirect selection the maize root system has evolved phenotypes suited to more intense competition for nitrogen. Sixteen maize varieties representing commercially successful lines over the past century were planted at two nitrogen levels and three planting densities. Root systems of the most recent material were 7 º more shallow, had one less nodal root per whorl, had double the distance from nodal root emergence to lateral branching, and had 14% more metaxylem vessels, but total mextaxylem vessel area remained unchanged because individual metaxylem vessels had 12% less area. Plasticity was also observed in cortical phenes such as aerenchyma, which increased at greater population densities. Simulation modelling with SimRoot demonstrated that even these relatively small changes in root architecture and anatomy could increase maize shoot growth by 16% in a high density and high nitrogen environment. The authors concluded that evolution of maize root phenotypes over the past century is consistent with increasing nitrogen use efficiency. Introgression of more contrasting root phene states into the germplasm of elite maize and determination of the functional utility of these phene states in multiple agronomic conditions could contribute to future yield gains. PMID:25795737

  14. Control of Aspergillus flavus in maize with plant essential oils and their components.

    PubMed

    Montes-Belmont, R; Carvajal, M

    1998-05-01

    The effects of 11 plant essential oils for maize kernel protection against Aspergillus flavus were studied. Tests were conducted to determine optimal levels of dosages for maize protection, effects of combinations of essential oils, and residual effects and toxicity of essential oils to maize plants. Principal constituents of eight essential oils were tested for ability to protect maize kernels. Essential oils of Cinnamomum zeylanicum (cinnamon), Mentha piperita (peppermint), Ocimum basilicum (basil), Origanum vulgare (origanum), Teloxys ambrosioides (the flavoring herb epazote), Syzygium aromaticum (clove), and Thymus vulgaris (thyme) caused a total inhibition of fungal development on maize kernels. Thymol and o-methoxycinnamaldehyde significantly reduced maize grain contamination. The optimal dosage for protection of maize varied from 3 to 8%. Combinations of C. zeylanicum with the remaining oils gave efficient control. A residual effect of C. zeylanicum was detected after 4 weeks of kernel treatment. No phytotoxic effect on germination and corn growth was detected with any of these oils.

  15. [Impacts of high temperature on maize production and adaptation measures in Northeast China].

    PubMed

    Yin, Xiao-gang; Wang, Meng; Kong, Qing-xin; Wang, Zhan-biao; Zhang, Hai-lin; Chu, Qing-quan; Wen, Xin-ya; Chen, Fu

    2015-01-01

    Heat stress is one of the major agro-meteorological hazards that affect maize production significantly in the farming region of Northeast China (NFR). This study analyzed the temporal and spatial changes of the accumulated temperature above 30 °C (AT) and the accumulated days with the maximum temperature above 30 °C (AD) in different maize growing phases under global warming. It further evaluated the impacts of extreme heat on maize yield in different regions, and put forward some adaptation measures to cope with heat stress for maize production in NFR. The results showed that during 1961 to 2010, the temperature in the maize growing season increased significantly. The maximum temperature in flowering phase was much larger than that in the other growing phases. Temperature increased at rates of 0. 16, 0. 14, 0.06 and 0.23 °C every ten years in the whole maize growing season, vegetative growth phase (from sowing to 11 days before flowering), flowering phase, and late growth phase (from 11 days after flowering to maturity), respectively. The AT in the whole maize growing season increased in NFR during the last 50 years with the highest in the southwest part of NFR, and that in the vegetative growth phase increased faster than in the other two phases. The AD in the whole maize growing season increased during the last 50 years with the highest in the southwest part of NFR, and that in the late growth phase increased faster than in the other two phases. Heat stress negatively affected maize yield during the maize growing season, particularly in the vegetative growth phase. The heat stress in Songliao Plain was much higher in comparison to the other regions. The adaptation measures of maize production to heat stress in NFR included optimizing crop structure, cultivating high temperature resistant maize varieties, improving maize production management and developing the maize production system that could cope with disasters.

  16. Silicon improves maize photosynthesis in saline-alkaline soils.

    PubMed

    Xie, Zhiming; Song, Ri; Shao, Hongbo; Song, Fengbin; Xu, Hongwen; Lu, Yan

    2015-01-01

    The research aimed to determine the effects of Si application on photosynthetic characteristics of maize on saline-alkaline soil, including photosynthetic rate (P n ), stomatal conductance (g s ), transpiration rate (E), and intercellular CO2 concentration (C i ) of maize in the field with five levels (0, 45, 90, 150, and 225 kg · ha(-1)) of Si supplying. Experimental results showed that the values of P n, g s, and C i of maize were significantly enhanced while the values of E of maize were dramatically decreased by certain doses of silicon fertilizers, which meant that Si application with proper doses significantly increased photosynthetic efficiency of maize in different growth stages under stressing environment of saline-alkaline soil. The optimal dose of Si application in this experiment was 150 kg · ha(-1) Si. It indicated that increase in maize photosynthesis under saline-alkaline stress took place by Si application with proper doses, which is helpful to improve growth and yield of maize. PMID:25629083

  17. A highly concentrated diet increases biogas production and the agronomic value of young bull's manure.

    PubMed

    Mendonça Costa, Mônica Sarolli Silva de; Lucas, Jorge de; Mendonça Costa, Luiz Antonio de; Orrico, Ana Carolina Amorim

    2016-02-01

    The increasing demand for animal protein has driven significant changes in cattle breeding systems, mainly in feedlots, with the use of young bulls fed on diets richer in concentrate (C) than in forage (F). These changes are likely to affect animal manure, demanding re-evaluation of the biogas production per kg of TS and VS added, as well as of its agronomic value as a biofertilizer, after anaerobic digestion. Here, we determined the biogas production and agronomic value (i.e., the macronutrient concentration in the final biofertilizer) of the manure of young bulls fed on diets with more (80% C+20% F; 'HighC' diet) or less (65% C+35% F; 'LowC' diet) concentrate, evaluating the effects of temperature (25, 35, and 40°C) and the use of an inoculum, during anaerobic digestion. A total of 24 benchtop reactors were used, operating in a semi-continuous system, with a 40-day hydraulic retention time (HRT). The manure from animals given the HighC diet had the greatest potential for biogas production, when digested with the use of an inoculum and at 35 or 40°C (0.6326 and 0.6207m(3)biogas/kg volatile solids, or VS, respectively). We observed the highest levels of the macronutrients N, P, and K in the biofertilizer from the manure of animals given HighC. Our results show that the manure of young bulls achieves its highest potential for biogas production and agronomic value when animals are fed diets richer in concentrate, and that biogas production increases if digestion is performed at higher temperatures, and with the use of an inoculum.

  18. Fine-tuning tomato agronomic properties by computational genome redesign.

    PubMed

    Carrera, Javier; Fernández Del Carmen, Asun; Fernández-Muñoz, Rafael; Rambla, Jose Luis; Pons, Clara; Jaramillo, Alfonso; Elena, Santiago F; Granell, Antonio

    2012-01-01

    Considering cells as biofactories, we aimed to optimize its internal processes by using the same engineering principles that large industries are implementing nowadays: lean manufacturing. We have applied reverse engineering computational methods to transcriptomic, metabolomic and phenomic data obtained from a collection of tomato recombinant inbreed lines to formulate a kinetic and constraint-based model that efficiently describes the cellular metabolism from expression of a minimal core of genes. Based on predicted metabolic profiles, a close association with agronomic and organoleptic properties of the ripe fruit was revealed with high statistical confidence. Inspired in a synthetic biology approach, the model was used for exploring the landscape of all possible local transcriptional changes with the aim of engineering tomato fruits with fine-tuned biotechnological properties. The method was validated by the ability of the proposed genomes, engineered for modified desired agronomic traits, to recapitulate experimental correlations between associated metabolites. PMID:22685389

  19. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    PubMed

    Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

    2016-08-01

    The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II. PMID:26919987

  20. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    PubMed

    Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

    2016-08-01

    The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II.

  1. Genetic dissection of agronomic traits in Capsicum baccatum var. pendulum.

    PubMed

    Moulin, M M; Rodrigues, R; Bento, C S; Gonçalves, L S A; Santos, J O; Sudré, C P; Viana, A P

    2015-03-20

    Genetic mapping is very useful for dissecting complex agronomic traits. Genetic mapping allows for identification of quantitative trait loci (QTL), provide knowledge on a gene position and its adjacent region, and enable prediction of evolutionary mechanisms, in addition to contributing to synteny studies. The aim of this study was to predict genetic values associated with different agronomic traits evaluated in an F2 population of Capsicum baccatum var. pendulum. Previously, a reference genetic map for C. baccatum was constructed, which included 183 markers (42 microsatellite, 85 inter-simple sequence repeat, and 56 random amplification of polymorphic DNA) arranged in 16 linkage groups. The map was used to identify QTL associated with 11 agronomic traits, including plant height, crown diameter, number of days to flowering, days to fruiting, number of fruits per plant, average fruit weight, fruit length, fruit diameter, fruit pulp thickness, soluble solids, and fruit dry weight. QTL mapping was performed by standard interval mapping. The number of small QTL effects ranged from 3-11, with a total of 61 QTL detected in 9 linkage groups. This is the first report involving QTL analysis for C. baccatum species.

  2. A Maize (E)-β-Caryophyllene Synthase Implicated in Indirect Defense Responses against Herbivores Is Not Expressed in Most American Maize Varieties[W][OA

    PubMed Central

    Köllner, Tobias G.; Held, Matthias; Lenk, Claudia; Hiltpold, Ivan; Turlings, Ted C.J.; Gershenzon, Jonathan; Degenhardt, Jörg

    2008-01-01

    The sesquiterpene (E)-β-caryophyllene is emitted by maize (Zea mays) leaves in response to attack by lepidopteran larvae like Spodoptera littoralis and released from roots after damage by larvae of the coleopteran Diabrotica virgifera virgifera. We identified a maize terpene synthase, Terpene Synthase 23 (TPS23), that produces (E)-β-caryophyllene from farnesyl diphosphate. The expression of TPS23 is controlled at the transcript level and induced independently by D. v. virgifera damage in roots and S. littoralis damage in leaves. We demonstrate that (E)-β-caryophyllene can attract natural enemies of both herbivores: entomopathogenic nematodes below ground and parasitic wasps, after an initial learning experience, above ground. The biochemical properties of TPS23 are similar to those of (E)-β-caryophyllene synthases from dicotyledons but are the result of repeated evolution. The sequence of TPS23 is maintained by positive selection in maize and its closest wild relatives, teosinte (Zea sp) species. The gene encoding TPS23 is active in teosinte species and European maize lines, but decreased transcription in most North American lines resulted in the loss of (E)-β-caryophyllene production. We argue that the (E)-β-caryophyllene defense signal was lost during breeding of the North American lines and that its restoration might help to increase the resistance of these lines against agronomically important pests. PMID:18296628

  3. MaizeGDB Community Curation Tools

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. The success of the MaizeGDB project largely can be attributed to the involvement of the community of maize geneticists. Members of the community have (1) made their data available by contributing to MaizeGD...

  4. Agronomical parameters, sugar profile and antioxidant compounds of "Catherine" peach cultivar influenced by different plum rootstocks.

    PubMed

    Font i Forcada, Carolina; Gogorcena, Yolanda; Moreno, María Ángeles

    2014-02-03

    The influence of seven plum rootstocks (Adesoto, Monpol, Montizo, Puebla de Soto 67 AD, PM 105 AD, St. Julien GF 655/2 and Constantí 1) on individual and total sugars, as well as on antioxidant content in fruit flesh of "Catherine" peaches, was evaluated for three years. Agronomical and basic fruit quality parameters were also determined. At twelve years after budding, significant differences were found between rootstocks for the different agronomic and fruit quality traits evaluated. The Pollizo plum rootstocks Adesoto and PM 105 AD seem to induce higher sweetness to peach fruits, based on soluble solids content, individual (sucrose, fructose and sorbitol) and total sugars. A clear tendency was also observed with the rootstock Adesoto, inducing the highest content of phenolics, flavonoids, vitamin C and relative antioxidant capacity (RAC). Thus, the results of this study demonstrate the significant effect of rootstock on the sugar profile and phytochemical characteristics of peach fruits. In addition, this work shows the importance of the sugar profile, because specific sugars play an important role in peach flavour quality, as well as the studied phytochemical compounds when looking for high quality peaches with enhanced health properties.

  5. Waterfowl foraging in winter-flooded ricefields: Any agronomic benefits for farmers?

    PubMed

    Brogi, Anne; Pernollet, Claire A; Gauthier-Clerc, Michel; Guillemain, Matthieu

    2015-12-01

    Winter-flooding of ricefields provides foraging habitat to waterfowl, which in return may bring agronomic benefits to farmers. Our study experimentally tested the effect of mallards (Anas platyrhynchos) on the standing stalks and weed seed bank in the Camargue (France), both of which present major challenges for farmers. Three duck densities were tested: (D1) 5 ducks ha(-1) (historical nocturnal density), (D2) 23 ducks ha(-1) (present nocturnal density), and (D3) 300 ducks ha(-1) (Asian rice-duck farming density). The ducks reduced the stalks significantly: -27 % (D1), -52 % (D2), and -91 % (D3). Conversely, they decreased the number of seeds by only 3 % (D3) and the seed mass by about 21 % (D1 and D3), which was not significant. Besides they had no effect on seed species richness. This study clearly demonstrates that the winter-flooding effect on straw decomposition can be enhanced by waterfowl foraging, hence showing an agronomic benefit from ducks to farmers. However, there was no clear effect in terms of seed bank reduction.

  6. Waterfowl foraging in winter-flooded ricefields: Any agronomic benefits for farmers?

    PubMed

    Brogi, Anne; Pernollet, Claire A; Gauthier-Clerc, Michel; Guillemain, Matthieu

    2015-12-01

    Winter-flooding of ricefields provides foraging habitat to waterfowl, which in return may bring agronomic benefits to farmers. Our study experimentally tested the effect of mallards (Anas platyrhynchos) on the standing stalks and weed seed bank in the Camargue (France), both of which present major challenges for farmers. Three duck densities were tested: (D1) 5 ducks ha(-1) (historical nocturnal density), (D2) 23 ducks ha(-1) (present nocturnal density), and (D3) 300 ducks ha(-1) (Asian rice-duck farming density). The ducks reduced the stalks significantly: -27 % (D1), -52 % (D2), and -91 % (D3). Conversely, they decreased the number of seeds by only 3 % (D3) and the seed mass by about 21 % (D1 and D3), which was not significant. Besides they had no effect on seed species richness. This study clearly demonstrates that the winter-flooding effect on straw decomposition can be enhanced by waterfowl foraging, hence showing an agronomic benefit from ducks to farmers. However, there was no clear effect in terms of seed bank reduction. PMID:26121948

  7. Biofuel, land and water: maize, switchgrass or Miscanthus?

    NASA Astrophysics Data System (ADS)

    Zhuang, Qianlai; Qin, Zhangcai; Chen, Min

    2013-03-01

    The productive cellulosic crops switchgrass and Miscanthus are considered as viable biofuel sources. To meet the 2022 national biofuel target mandate, actions must be taken, e.g., maize cultivation must be intensified and expanded, and other biofuel crops (switchgrass and Miscanthus) must be cultivated. This raises questions on the use efficiencies of land and water; to date, the demand on these resources to meet the national biofuel target has rarely been analyzed. Here, we present a data-model assimilation analysis, assuming that maize, switchgrass and Miscanthus will be grown on currently available croplands in the US. Model simulations suggest that maize can produce 3.0-5.4 kiloliters (kl) of ethanol for every hectare of land, depending on the feedstock to ethanol conversion efficiency; Miscanthus has more than twice the biofuel production capacity relative to maize, and switchgrass is the least productive of the three potential sources of ethanol. To meet the biofuel target, about 26.5 million hectares of land and over 90 km3 of water (of evapotranspiration) are needed if maize grain alone is used. If Miscanthus was substituted for maize, the process would save half of the land and one third of the water. With more advanced biofuel conversion technology for Miscanthus, only nine million hectares of land and 45 km3 of water would probably meet the national target. Miscanthus could be a good alternative biofuel crop to maize due to its significantly lower demand for land and water on a per unit of ethanol basis.

  8. Growing sensitivity of maize to water scarcity under climate change

    NASA Astrophysics Data System (ADS)

    Meng, Qingfeng; Chen, Xinping; Lobell, David B.; Cui, Zhenling; Zhang, Yi; Yang, Haishun; Zhang, Fusuo

    2016-01-01

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.

  9. Transcriptional responses of maize seedling root to phosphorus starvation.

    PubMed

    Lin, Hai-Jian; Gao, Jian; Zhang, Zhi-Ming; Shen, Ya-Ou; Lan, Hai; Liu, Li; Xiang, Kui; Zhao, Maojun; Zhou, Shufeng; Zhang, Yong-Zhong; Gao, Shi-Bin; Pan, Guang-Tang

    2013-09-01

    Maize (Zea mays) is the most widely cultivated crop around the world, however, it is commonly affected by phosphate (Pi) deficiency and the underlying molecular basis of responses mechanism is still unknown. In this study, the transcriptional response of maize roots to Pi starvation at 3 days after the onset of Pi deprivation was assessed. The investigation revealed a total of 283 Pi-responsive genes, of which 199 and 84 genes were found to be either up- or down-regulated respectively, by 2-fold or more. Pi-responsive genes were found to be involved in sugar and nitrogen metabolic pathways, ion transport, signal transduction, transcriptional regulation, and other processes related to growth and development. In addition, the expression patterns of maize inorganic phosphorus transporters, acid phosphatase, phytase, 2-deoxymugineic acid synthase1, POD and MYB transcription factor were validated in 178 roots response to low phosphorus stress. of which, two genes encoding phytase and acid phosphatase were significantly induced by Pi deficiency and may play a pivotal role in the process of absorption and re-utilization of Pi in Maize. These results not only enhance our knowledge about molecular processes associated with Pi deficiency, but also facilitate the identification of key molecular determinants for improving Pi use in maize. Moreover, this work sets a framework to produce Pi-specific maize microarrays to study the changes in global gene expression between Pi-efficient and Pi-inefficient maize genotypes. PMID:23670044

  10. Growing sensitivity of maize to water scarcity under climate change.

    PubMed

    Meng, Qingfeng; Chen, Xinping; Lobell, David B; Cui, Zhenling; Zhang, Yi; Yang, Haishun; Zhang, Fusuo

    2016-01-01

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem. PMID:26804136

  11. Viruses in maize and Johnsongrass in southern Ohio.

    PubMed

    Stewart, L R; Teplier, R; Todd, J C; Jones, M W; Cassone, B J; Wijeratne, S; Wijeratne, A; Redinbaugh, M G

    2014-12-01

    The two major U.S. maize viruses, Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV), emerged in southern Ohio and surrounding regions in the 1960s and caused significant losses. Planting resistant varieties and changing cultural practices has dramatically reduced virus impact in subsequent decades. Current information on the distribution, diversity, and impact of known and potential U.S. maize disease-causing viruses is lacking. To assess the current reservoir of viruses present at the sites of past disease emergence, we used a combination of serological testing and next-generation RNA sequencing approaches. Here, we report enzyme-linked immunosorbent assay and RNA-Seq data from samples collected over 2 years to assess the presence of viruses in cultivated maize and an important weedy reservoir, Johnsongrass (Sorghum halepense). Results revealed a persistent reservoir of MDMV and two strains of MCDV in Ohio Johnsongrass. We identified sequences of several other grass-infecting viruses and confirmed the presence of Wheat mosaic virus in Ohio maize. Together, these results provide important data for managing virus disease in field corn and sweet corn maize crops, and identifying potential future virus threats.

  12. Growing sensitivity of maize to water scarcity under climate change.

    PubMed

    Meng, Qingfeng; Chen, Xinping; Lobell, David B; Cui, Zhenling; Zhang, Yi; Yang, Haishun; Zhang, Fusuo

    2016-01-25

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.

  13. Field trials to evaluate the effects of transgenic cry1Ie maize on the community characteristics of arthropod natural enemies

    PubMed Central

    Guo, Jingfei; He, Kanglai; Hellmich, Richard L.; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Ahmed, Tofael; Wang, Zhenying

    2016-01-01

    Possible non-target effect of transgenic cry1Ie maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr comparison of transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community biodiversity were compared with whole plant inspections, pitfall traps and suction sampler. Natural enemy diversity indices (Shannon-Wiener’, Simpson’s and Pielou’s index) and abundance suggested there were no significant differences between the two types of maize. The only exceptions were the Pielou’s index for whole plant inspections in 2013 and abundance for pitfall traps in 2012, which were significantly higher in Bt maize than those of non-Bt maize. The main species of natural enemies were identical in Bt and non-Bt maize plots for each method and the three methods combined. For whole plant inspections, Bt maize had no time-dependent effect on the entire arthropod natural enemy community, and also no effect on community dissimilarities between Bt and non-Bt maize plots. These results suggested that despite the presence of a relatively minor difference in natural enemy communities between Bt and non-Bt maize, transgenic cry1Ie maize had little, if any, effect on natural enemy community biodiversity. PMID:26915985

  14. Field trials to evaluate the effects of transgenic cry1Ie maize on the community characteristics of arthropod natural enemies.

    PubMed

    Guo, Jingfei; He, Kanglai; Hellmich, Richard L; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Ahmed, Tofael; Wang, Zhenying

    2016-02-26

    Possible non-target effect of transgenic cry1Ie maize exerts on natural enemy community biodiversity in the field is unresolved. In the present study, a 2-yr comparison of transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) on natural enemy community biodiversity were compared with whole plant inspections, pitfall traps and suction sampler. Natural enemy diversity indices (Shannon-Wiener', Simpson's and Pielou's index) and abundance suggested there were no significant differences between the two types of maize. The only exceptions were the Pielou's index for whole plant inspections in 2013 and abundance for pitfall traps in 2012, which were significantly higher in Bt maize than those of non-Bt maize. The main species of natural enemies were identical in Bt and non-Bt maize plots for each method and the three methods combined. For whole plant inspections, Bt maize had no time-dependent effect on the entire arthropod natural enemy community, and also no effect on community dissimilarities between Bt and non-Bt maize plots. These results suggested that despite the presence of a relatively minor difference in natural enemy communities between Bt and non-Bt maize, transgenic cry1Ie maize had little, if any, effect on natural enemy community biodiversity.

  15. Effect of agronomical practices on carpology, fruit and oil composition, and oil sensory properties, in olive (Olea europaea L.).

    PubMed

    Rosati, Adolfo; Cafiero, Caterina; Paoletti, Andrea; Alfei, Barbara; Caporali, Silvia; Casciani, Lorena; Valentini, Massimiliano

    2014-09-15

    We examined whether some agronomical practices (i.e. organic vs. conventional) affect olive fruit and oil composition, and oil sensory properties. Fruit characteristics (i.e. fresh and dry weight of pulp and pit, oil content on a fresh and dry weight basis) did not differ. Oil chemical traits did not differ except for increased content of polyphenols in the organic treatments, and some changes in the acidic composition. Sensory analysis revealed increased bitterness (both cultivars) and pungency (Frantoio) and decreased sweetness (Frantoio) in the organic treatment. Fruit metabolomic analysis with HRMAS-NMR indicated significant changes in some compounds including glycocholate, fatty acids, NADPH, NADP+, some amino acids, thymidine, trigonelline, nicotinic acid, 5,6-dihydrouracil, hesanal, cis-olefin, β-D-glucose, propanal and some unassigned species. The results suggest that agronomical practices may have effects on fruit composition that may be difficult to detect unless a broad-spectrum analysis is used.

  16. Maize Lethal Necrosis (MLN), an Emerging Threat to Maize-Based Food Security in Sub-Saharan Africa.

    PubMed

    Mahuku, George; Lockhart, Benham E; Wanjala, Bramwel; Jones, Mark W; Kimunye, Janet Njeri; Stewart, Lucy R; Cassone, Bryan J; Sevgan, Subramanian; Nyasani, Johnson O; Kusia, Elizabeth; Kumar, P Lava; Niblett, C L; Kiggundu, Andrew; Asea, Godfrey; Pappu, Hanu R; Wangai, Anne; Prasanna, Boddupalli M; Redinbaugh, Margaret G

    2015-07-01

    In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on maize in Kenya. The disease has since been confirmed in Rwanda and the Democratic Republic of Congo, and similar symptoms have been reported in Tanzania, Uganda, South Sudan, and Ethiopia. In 2012, yield losses of up to 90% resulted in an estimated grain loss of 126,000 metric tons valued at $52 million in Kenya alone. In eastern Africa, MLN was found to result from coinfection of maize with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), although MCMV alone appears to cause significant crop losses. We summarize here the results of collaborative research undertaken to understand the biology and epidemiology of MLN in East Africa and to develop disease management strategies, including identification of MLN-tolerant maize germplasm. We discuss recent progress, identify major issues requiring further research, and discuss the possible next steps for effective management of MLN.

  17. Characterization of a novel glycine-rich protein from the cell wall of maize silk tissues.

    PubMed

    Tao, T Y; Ouellet, T; Dadej, K; Miller, S S; Johnson, D A; Singh, J

    2006-08-01

    The isolation, characterization and regulation of expression of a maize silk-specific gene is described. zmgrp5 (Zea mays glycine-rich protein 5) encodes a 187 amino acid glycine-rich protein that displays developmentally regulated silk-specific expression. Northern, Western, in situ mRNA hybridization and transient gene expression analyses indicate that zmgrp5 is expressed in silk hair and in cells of the vascular bundle and pollen tube transmitting tissue elements. The protein is secreted into the extracellular matrix and is localized in the cell wall fraction mainly through interactions mediated by covalent disulphide bridges. Taken together, these results suggest that the protein may play a role in maintaining silk structure during development. This is the first documented isolation of a stigma-specific gene from maize, an important agronomic member of the Poaceae family. PMID:16528565

  18. Efficiency of utilization of nitrogen coated with urease inhibitor in maize.

    PubMed

    Okumura, Ricardo S; Mariano, Daiane de C; Zaccheo, Paulo V C; de Albuquerque, Amanda N; Giebelmeier, Carmo G; da S Lobato, Allan K; Franco, Antônio A N; de Oliveira, Neto Cândido F; Saldanha, Eduardo C M; da Conceição, Heráclito E O; da Silva, Raimundo T L

    2013-09-01

    This study aimed to evaluate under field conditions the efficiency in the use ofN coated with urease inhibitor in maize. The experiment was conducted in the year of 2007/2008. The experimental design was a randomized block design in a factorial 2 x 6, with five repetitions, constituted the N sources (common and coated with urease inhibitor) and levels (0, 40, 80, 120, 160 and 200 kg ha-1 of N) sidedressing nitrogen application in the growth stage V4. Based on the data obtained were determined recovery efficiencies, utilization, agronomic and physiological N applied. In all cases, the efficiency levels for maize were influenced by levels of sidedressing nitrogen application, in which increasing levels of N resulted in a decrease of the efficiencies, regardless of the source being common urea or coated with urease inhibitor. PMID:24498841

  19. Efficiency of utilization of nitrogen coated with urease inhibitor in maize.

    PubMed

    Okumura, Ricardo S; Mariano, Daiane de C; Zaccheo, Paulo V C; de Albuquerque, Amanda N; Giebelmeier, Carmo G; da S Lobato, Allan K; Franco, Antônio A N; de Oliveira, Neto Cândido F; Saldanha, Eduardo C M; da Conceição, Heráclito E O; da Silva, Raimundo T L

    2013-09-01

    This study aimed to evaluate under field conditions the efficiency in the use ofN coated with urease inhibitor in maize. The experiment was conducted in the year of 2007/2008. The experimental design was a randomized block design in a factorial 2 x 6, with five repetitions, constituted the N sources (common and coated with urease inhibitor) and levels (0, 40, 80, 120, 160 and 200 kg ha-1 of N) sidedressing nitrogen application in the growth stage V4. Based on the data obtained were determined recovery efficiencies, utilization, agronomic and physiological N applied. In all cases, the efficiency levels for maize were influenced by levels of sidedressing nitrogen application, in which increasing levels of N resulted in a decrease of the efficiencies, regardless of the source being common urea or coated with urease inhibitor.

  20. [Effects of controlled-release fertilizers on summer maize grain yield, field ammonia volatilization, and fertilizer nitrogen use efficiency].

    PubMed

    Zhao, Bin; Dong, Shu-Ting; Wang, Kong-Jun; Zhang, Ji-Wang; Liu, Peng

    2009-11-01

    A field experiment with colophony-coated fertilizer (CRF) and sulfur-coated fertilizer (SCF) showed that under the same application rates of N, P and K, applying CRF and SCF increased the summer maize grain yield by 13.15% and 14.15%, respectively, compared to the application of common compound fertilizer CCF. When the applied amount of CRF and SCF was decreased by 25%, the yield increment was 9.69% and 10.04%, respectively; and when the applied amount of CRF and SCF was decreased by 50%, the yield had less difference with that under CCF application. The field ammonia volatilization rate in treatments CRF and SCF increased slowly, with a peak appeared 7 days later than that in treatment CCF, and the total amount of ammonia volatilization in treatments CRF and SCF was ranged from 0.78 kg N x hm(-2) to 4.43 kg N x hm(-2), with a decrement of 51.34%-91.34% compared to that in treatment CCF. The fertilizer nitrogen use efficiency and agronomic nitrogen use efficiency of CRF and SCF were also significantly higher than those of CCF. PMID:20136000

  1. [Effects of controlled-release fertilizers on summer maize grain yield, field ammonia volatilization, and fertilizer nitrogen use efficiency].

    PubMed

    Zhao, Bin; Dong, Shu-Ting; Wang, Kong-Jun; Zhang, Ji-Wang; Liu, Peng

    2009-11-01

    A field experiment with colophony-coated fertilizer (CRF) and sulfur-coated fertilizer (SCF) showed that under the same application rates of N, P and K, applying CRF and SCF increased the summer maize grain yield by 13.15% and 14.15%, respectively, compared to the application of common compound fertilizer CCF. When the applied amount of CRF and SCF was decreased by 25%, the yield increment was 9.69% and 10.04%, respectively; and when the applied amount of CRF and SCF was decreased by 50%, the yield had less difference with that under CCF application. The field ammonia volatilization rate in treatments CRF and SCF increased slowly, with a peak appeared 7 days later than that in treatment CCF, and the total amount of ammonia volatilization in treatments CRF and SCF was ranged from 0.78 kg N x hm(-2) to 4.43 kg N x hm(-2), with a decrement of 51.34%-91.34% compared to that in treatment CCF. The fertilizer nitrogen use efficiency and agronomic nitrogen use efficiency of CRF and SCF were also significantly higher than those of CCF.

  2. Isozyme marker loci associated with cold tolerance and maturity in maize.

    PubMed

    Guse, R A; Coors, J G; Drolsom, P N; Tracy, W F

    1988-09-01

    Two maize (Zea mays L.) populations, AS1(S) and ECR-A, were evaluated for allozyme frequency changes associated with selection for improved seedling emergence, early season vigor and early maturity. Eleven marker loci were examined and four loci were used for indirect selection in an attempt to modify cold tolerance and maturity. Allozyme-selected divergent subpopulations were produced by compositing selected S1 progeny from cycle one (C1) of AS1(S) and from C2 of ECR-A. These subpopulations and S1 generations from all cycles resulting from phenotypic selection, ECR-A C1 through C7 and AS1(S) CO through C6, were tested in cold tolerance and agronomic performance trials over five environments in 1986. Seedling emergence and seedling dry weight did not improve with phenotypic selection in ECR-A, while plant height, ear height, grain yield, grain moisture, days to mid-silk and days to mid-pollen were reduced significantly. Contrasts between divergent allozyme-selected subpopulations from ECR-A were significant for grain moisture and mid-pollen date. For AS1(S), seeding emergence increased, while plant and ear height decreased with phenotypic selection. Contrasts between allozyme-selected subpopulations were significant for plant and ear height. Changes associated with marker-based selection for AS1(S) were not in the same direction as with phenotypic selection. Selection for favorable allozyme genotypes may be effective in changing certain traits in populations that have been modified by direct selection, however results may not be predictable. PMID:24232204

  3. Multi-trait QTL analysis for agronomic and quality characters of Agaricus bisporus (button mushrooms).

    PubMed

    Gao, Wei; Baars, Johan J P; Maliepaard, Chris; Visser, Richard G F; Zhang, Jinxia; Sonnenberg, Anton S M

    2016-12-01

    The demand for button mushrooms of high quality is increasing. Superior button mushroom varieties require the combination of multiple traits to maximize productivity and quality. Very often these traits are correlated and should, therefore, be evaluated together rather than as single traits. In order to unravel the genetic architecture of multiple traits of Agaricus bisporus and the genetic correlations among traits, we have investigated a total of six agronomic and quality traits through multi-trait QTL analyses in a mixed-model. Traits were evaluated in three heterokaryon sets. Significant phenotypic correlations were observed among traits. For instance, earliness (ER) correlated to firmness (FM), cap color, and compost colonization, and FM correlated to scales (SC). QTLs of different traits located on the same chromosomes genetically explains the phenotypic correlations. QTL detected on chromosome 10 mainly affects three traits, i.e., ER, FM and SC. It explained 31.4 % phenotypic variation of SC on mushroom cap (heterokaryon Set 1), 14.9 % that of the FM (heterokaryon Set 3), and 14.2 % that of ER (heterokaryon Set 3). High value alleles from the wild parental line showed beneficial effects for several traits, suggesting that the wild germplasm is a valuable donor in terms of those traits. Due to the limitations of recombination pattern, we only made a start at understanding the genetic base for several agronomic and quality traits in button mushrooms. PMID:27620731

  4. Compositional and Agronomic Evaluation of Sorghum Biomass as a Potential Feedstock for Renewable Fuels

    SciTech Connect

    Dahlberg, J.; Wolfrum, E.; Bean, B.; Rooney, W. L.

    2011-12-01

    One goal of the Biomass Research and Development Technical Advisory Committee was to replace 30% of current U.S. petroleum consumption with biofuels by 2030. This will take mixtures of various feedstocks; an annual biomass feedstock such as sorghum will play an important role in meeting this goal. Commercial forage sorghum samples collected from field trials grown in Bushland, TX in 2007 were evaluated for both agronomic and compositional traits. Biomass compositional analysis of the samples was performed at the National Renewable Energy Lab in Golden, CO following NREL Laboratory Analytical Procedures. Depending on the specific cultivar, several additional years of yield data for this location were considered in establishing agronomic potential. Results confirm that sorghum forages can produce high biomass yields over multiple years and varied growing conditions. In addition, the composition of sorghum shows significant variation, as would be expected for most crops. Using theoretical estimates for ethanol production, the sorghum commercial forages examined in this study could produce an average of 6147 L ha{sup -1} of renewable fuels. Given its genetic variability, a known genomic sequence, a robust seed industry, and biomass composition, sorghum will be an important annual feedstock to meet the alternative fuel production goals legislated by the US Energy Security Act of 2007.

  5. Genes associated with agronomic traits in non-heading Chinese cabbage identified by expression profiling

    PubMed Central

    2014-01-01

    Background The genomes of non-heading Chinese cabbage (Brassica rapa ssp. chinensis), heading Chinese cabbage (Brassica rapa ssp. pekinensis) and their close relative Arabidopsis thaliana have provided important resources for studying the evolution and genetic improvement of cruciferous plants. Natural growing conditions present these plants with a variety of physiological challenges for which they have a repertoire of genes that ensure adaptability and normal growth. We investigated the differential expressions of genes that control adaptability and development in plants growing in the natural environment to study underlying mechanisms of their expression. Results Using digital gene expression tag profiling, we constructed an expression profile to identify genes related to important agronomic traits under natural growing conditions. Among three non-heading Chinese cabbage cultivars, we found thousands of genes that exhibited significant differences in expression levels at five developmental stages. Through comparative analysis and previous reports, we identified several candidate genes associated with late flowering, cold tolerance, self-incompatibility, and leaf color. Two genes related to cold tolerance were verified using quantitative real-time PCR. Conclusions We identified a large number of genes associated with important agronomic traits of non-heading Chinese cabbage. This analysis will provide a wealth of resources for molecular-assisted breeding of cabbage. The raw data and detailed results of this analysis are available at the website http://nhccdata.njau.edu.cn. PMID:24655567

  6. Remote sensing for quantification of agronomic properties

    NASA Astrophysics Data System (ADS)

    Sullivan, Dana Grace

    Remote sensing (RS) may be used to rapidly assess surface features and facilitate natural resource management, precision agriculture and soil survey. Information obtained in such a way would streamline data collection and improve diagnostic capabilities. Current RS technology has had limited testing, particularly within the Southeast. Our study was designed to evaluate RS as a rapid assessment tool in three different natural resource applications: nitrogen (N) management in a corn crop (Zea mays L.), assessment of in situ crop residue cover, and quantification of near-surface soil properties. In 2000, study sites were established in four physiographic provinces of Alabama: Tennessee Valley, Ridge and Valley, Appalachian Plateau, and Coastal Plain. Spectral measurements were acquired via spectroradiometer (350--1050 nm), airborne ATLAS multispectral scanner (400--12,500 nm), and IKONOS satellite (450--900 nm). Corn plots were established from fresh-tilled ground in a completely randomized design at the Appalachian Plateau and Coastal Plain study sites in 2000. Plots received four N rates (0, 56, 112, and 168 kg N ha-1 ), and were maintained for three consecutive growing seasons. Spectroradiometer data were acquired biweekly from V6-R2 and ATLAS and IKONOS were acquired per availability. Results showed vegetation indices derived from hand-held spectroradiometer measurements as early as V6-V8 were linearly related to yield and tissue N. ATLAS imagery showed promise at the AP site during the V6 stage (r2 = 0.66), but no significant relationships between plant N and IKONOS imagery were observed. Residue plots (15m x 15m) were established at the Appalachian Plateau and Coastal Plain in 2000 and 200. Residue treatments consisted of hand applied wheat straw cover (0, 10 20, 50, or 80%) arranged in a completely randomized design. Spectroradiometer data were acquired monthly and ATLAS and IKONOS were acquired per availability. Residue cover estimates were best with ATLAS

  7. Performance of broiler chickens fed event DAS-40278-9 maize containing the aryloxyalkanoate dioxygenase-1 protein.

    PubMed

    Herman, Rod A; Dunville, Christina M; Juberg, Daland R; Fletcher, Dale W; Cromwell, Gary L

    2011-08-01

    Event DAS-40278-9 maize grain (containing the aryloxyalkanoate dioxygenase-1 protein), a non-transgenic near-isogenic maize grain, or one of three commercial maize grains were included in the diets of broiler chickens for six weeks. Growth, feed conversion, and carcass measurements indicated no significant difference between the groups fed the diets containing the DAS-40278-9 maize grain and those fed diets containing the matched control grain. The absence of adverse effects in this study supports the dietary safety of the AAD-1 protein expressed in event DAS-40278-9 maize.

  8. Maize pan-transcriptome provides novel insights into genome complexity and quantitative trait variation

    PubMed Central

    Jin, Minliang; Liu, Haijun; He, Cheng; Fu, Junjie; Xiao, Yingjie; Wang, Yuebin; Xie, Weibo; Wang, Guoying; Yan, Jianbing

    2016-01-01

    Gene expression variation largely contributes to phenotypic diversity and constructing pan-transcriptome is considered necessary for species with complex genomes. However, the regulation mechanisms and functional consequences of pan-transcriptome is unexplored systematically. By analyzing RNA-seq data from 368 maize diverse inbred lines, we identified almost one-third nuclear genes under expression presence and absence variation, which tend to play regulatory roles and are likely regulated by distant eQTLs. The ePAV was directly used as “genotype” to perform GWAS for 15 agronomic phenotypes and 526 metabolic traits to efficiently explore the associations between transcriptomic and phenomic variations. Through a modified assembly strategy, 2,355 high-confidence novel sequences with total 1.9 Mb lengths were found absent within reference genome. Ten randomly selected novel sequences were fully validated with genomic PCR, including another two NBS_LRR candidates potentially affect flavonoids and disease-resistance. A simulation analysis suggested that the pan-transcriptome of the maize whole kernel is approaching a maximum value of 63,000 genes, and through developing two test-cross populations and surveying several most important yield traits, the dispensable genes were shown to contribute to heterosis. Novel perspectives and resources to discover maize quantitative trait variations were provided to better understand the kernel regulation networks and to enhance maize breeding. PMID:26729541

  9. Association Analysis of Simple Sequence Repeat (SSR) Markers with Agronomic Traits in Tall Fescue (Festuca arundinacea Schreb.)

    PubMed Central

    Chen, Liang; Sun, Xiaoyan; Yang, Yong; Liu, Hongmei; Xu, Qingguo

    2015-01-01

    Tall fescue is widely used in temperate regions throughout the world as a dominant forage grass as well as a turfgrass, in pastoral and turf industry. However, the utilization of tall fescue was limited because of its leaf roughness, poor regeneration ability and poor stress resistance. New cultivars were desirable in modern pastoral industries exceed the potential of existing cultivars. Therefore, well understanding the agronomic traits and describing germplasms would help to overcome these constraints, and morphological evaluation of tall fescue germplasm is the key component in selecting rational parents for hybridization breeding. However, describing the morphological traits of tall fescue germplasm is costly and time-consuming. Fortunately, biotechnology approaches can supplement conventional breeding efforts for tall fescue improvement. Association mapping, as a powerful approach to identify association between agronomic traits and molecular markers has been widely used for enhancing the utilization, conservation and management of the tall fescue germplasms. Therefore, in the present research, 115 tall fescue accessions from different origins (25 accessions are cultivars; 31 accessions from America; 32 accessions from European; 7 accessions from Africa; 20 accessions from Asia), were evaluated for agronomic traits and genetic diversity with 90 simple sequence repeat (SSR) markers. The panel displayed significant variation in spike count per plant (SCP) and spike weight (SW). However, BCS performed the lowest CV among all the observed agronomic traits. Three subpopulations were identified within the collections but no obvious relative kinship (K) was found. The GLM model was used to describe the association between SSR and agronomic traits. Fifty-one SSR markers associated with agronomic traits were observed. Twelve single-associated markers were associated with PH; six single-associated markers were associated with BCS; eight single-associated markers were

  10. Flowering Time-Regulated Genes in Maize Include the Transcription Factor ZmMADS11[OPEN

    PubMed Central

    Alter, Philipp; Bircheneder, Susanne; Schlüter, Urte; Gahrtz, Manfred

    2016-01-01

    Flowering time (FTi) control is well examined in the long-day plant Arabidopsis (Arabidopsis thaliana), and increasing knowledge is available for the short-day plant rice (Oryza sativa). In contrast, little is known in the day-neutral and agronomically important crop plant maize (Zea mays). To learn more about FTi and to identify novel regulators in this species, we first compared the time points of floral transition of almost 30 maize inbred lines and show that tropical lines exhibit a delay in flowering transition of more than 3 weeks under long-day conditions compared with European flint lines adapted to temperate climate zones. We further analyzed the leaf transcriptomes of four lines that exhibit strong differences in flowering transition to identify new key players of the flowering control network in maize. We found strong differences among regulated genes between these lines and thus assume that the regulation of FTi is very complex in maize. Especially genes encoding MADS box transcriptional regulators are up-regulated in leaves during the meristem transition. ZmMADS1 was selected for functional studies. We demonstrate that it represents a functional ortholog of the central FTi integrator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) of Arabidopsis. RNA interference-mediated down-regulation of ZmMADS1 resulted in a delay of FTi in maize, while strong overexpression caused an early-flowering phenotype, indicating its role as a flowering activator. Taken together, we report that ZmMADS1 represents a positive FTi regulator that shares an evolutionarily conserved function with SOC1 and may now serve as an ideal stating point to study the integration and variation of FTi pathways also in maize. PMID:27457125

  11. Flowering Time-Regulated Genes in Maize Include the Transcription Factor ZmMADS1.

    PubMed

    Alter, Philipp; Bircheneder, Susanne; Zhou, Liang-Zi; Schlüter, Urte; Gahrtz, Manfred; Sonnewald, Uwe; Dresselhaus, Thomas

    2016-09-01

    Flowering time (FTi) control is well examined in the long-day plant Arabidopsis (Arabidopsis thaliana), and increasing knowledge is available for the short-day plant rice (Oryza sativa). In contrast, little is known in the day-neutral and agronomically important crop plant maize (Zea mays). To learn more about FTi and to identify novel regulators in this species, we first compared the time points of floral transition of almost 30 maize inbred lines and show that tropical lines exhibit a delay in flowering transition of more than 3 weeks under long-day conditions compared with European flint lines adapted to temperate climate zones. We further analyzed the leaf transcriptomes of four lines that exhibit strong differences in flowering transition to identify new key players of the flowering control network in maize. We found strong differences among regulated genes between these lines and thus assume that the regulation of FTi is very complex in maize. Especially genes encoding MADS box transcriptional regulators are up-regulated in leaves during the meristem transition. ZmMADS1 was selected for functional studies. We demonstrate that it represents a functional ortholog of the central FTi integrator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) of Arabidopsis. RNA interference-mediated down-regulation of ZmMADS1 resulted in a delay of FTi in maize, while strong overexpression caused an early-flowering phenotype, indicating its role as a flowering activator. Taken together, we report that ZmMADS1 represents a positive FTi regulator that shares an evolutionarily conserved function with SOC1 and may now serve as an ideal stating point to study the integration and variation of FTi pathways also in maize. PMID:27457125

  12. Nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology: lysine maize as a case study.

    PubMed

    Glenn, Kevin C

    2007-01-01

    During the last decade, the area of biotech crops modified for agronomic input traits (e.g., herbicide tolerance and insect protection) has increased to 90 million halyear, grown by over 8 million farmers in a total of 17 countries. As adoption of these improved agronomic trait biotech crops has grown, so has interest in biotech crops that have improved nutritional characteristics for use as feed and food. A previous publication by the International Life Sciences Institute (ILSI) reported on the principles and concepts proposed for the nutritional and safety assessments of foods and feeds nutritionally improved through biotechnology. In this paper, the guidelines and principles recommended in the earlier publication are discussed relative to a specific case study, Lysine maize. Lysine maize is a feed ingredient with enhanced nutritional characteristics for poultry and swine and provides an alternative to the need for addition of supplemental lysine to some diets for these animals. The 2004 Task Force of the ILSI has also applied the concepts from that report to 4 other case studies: sweet potato enriched in provitamin A (2 examples, one using biotechnology and one using conventional breeding); Golden Rice 2; double-embryo maize; and ASP-1 enhanced protein sweet potato.

  13. MaizeGDB: The Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genetic, genomic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project's website...

  14. MaizeGDB: The Maize Genetics and Genomics Database.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the community database for biological information about the crop plant Zea mays. Genomic, genetic, sequence, gene product, functional characterization, literature reference, and person/organization contact information are among the datatypes stored at MaizeGDB. At the project’s website...

  15. Effects of Selected Diazotrophs on Maize Growth

    PubMed Central

    Kifle, Medhin H.; Laing, Mark D.

    2016-01-01

    Laboratory, greenhouse, and field experiments were conducted at the University of KwaZulu-Natal, Pietermaritzburg, South Africa in the 2010/2011 and 2011∖2012 seasons to study the effects of eight strains of diazotrophic bacteria on the growth and yield of maize. Maize seeds were treated with Bacillus megaterium (V16), Pseudomonas sp. (StB5, A3, A6, and A61), Burkholderia ambifaria (V9), Enterobacter cloacae (L1) and Pantoea ananatis (LB5), aiming to stimulate plant growth, and maintain or increase yields while reducing the need for N fertilization. All the diazotrophic bacteria increased germination of maize seed, and Pseudomonas sp. (StB5) and B. megaterium (V16) significantly increased shoot length. Pseudomonas sp. (StB5), B. megaterium (V16), E. cloacae (L1), B. ambifaria (V9), and Pseudomonas sp. (A3) very significantly increased root length and seed vigor index. Under greenhouse conditions, plants treated with diazotrophic bacteria developed more leaf chlorophyll and greater dry weight, albeit not significantly (n.s.). In a field trial in 2010/2011, application of the best five diazotrophic bacteria, with or without 33% N-fertilizer, had no significant effect on germination, grain yield, dry weight, plant height and leaf chlorophyll. In the 2011/2012 growing season, at 60 days after planting (DAP), all the diazotrophic bacteria increased plant dry weights to equal that of the fertilized control (33%N-fertilizer) (n.s.). After inoculation with the diazotrophs alone increased plant heights (n.s.), and chlorophyll contents (n.s.). With the addition of 33%N-fertilizer at planting, the diazotrophs still caused increases of chlorophyll content relative to the control with 33%N (n.s.). It may be concluded that the tested diazotrophs alone may be beneficial for use on maize growth. PMID:27713756

  16. Influence of Agronomic and Climatic Factors on Fusarium Infestation and Mycotoxin Contamination of Cereals in Norway

    PubMed Central

    Bernhoft, A.; Torp, M.; Clasen, P.-E.; Løes, A.-K.; Kristoffersen, A.B.

    2012-01-01

    A total of 602 samples of organically and conventionally grown barley, oats and wheat was collected at grain harvest during 2002–2004 in Norway. Organic and conventional samples were comparable pairs regarding cereal species, growing site and harvest time, and were analysed for Fusarium mould and mycotoxins. Agronomic and climatic factors explained 10–30% of the variation in Fusarium species and mycotoxins. Significantly lower Fusarium infestation and concentrations of important mycotoxins were found in the organic cereals. The mycotoxins deoxynivalenol (DON) and HT-2 toxin (HT-2) constitute the main risk for human and animal health in Norwegian cereals. The impacts of various agronomic and climatic factors on DON and HT-2 as well as on their main producers F. graminearum and F. langsethiae and on total Fusarium were tested by multivariate statistics. Crop rotation with non-cereals was found to reduce all investigated characteristics significantly – mycotoxin concentrations as well as various Fusarium infestations. No use of mineral fertilisers and herbicides was also found to decrease F. graminearum, whereas lodged fields increased the occurrence of this species. No use of herbicides was also found to decrease F. langsethiae, but for this species the occurrence was lower in lodged fields. Total Fusarium infestation was decreased with no use of fungicides or mineral fertilisers, and with crop rotation, as well as by using herbicides and increased by lodged fields. Clay and to some extent silty soils seemed to reduce F. graminearum in comparison with sandy soils. Concerning climate factors, low temperature before grain harvest was found to increase DON; and high air humidity before harvest to increase HT-2. F. graminearum was negatively correlated with precipitation in July but correlated with air humidity before harvest. F. langsethiae was correlated with temperature in July. Total Fusarium increased with increasing precipitation in July. Organic cereal

  17. Influence of agronomic and climatic factors on Fusarium infestation and mycotoxin contamination of cereals in Norway.

    PubMed

    Bernhoft, A; Torp, M; Clasen, P-E; Løes, A-K; Kristoffersen, A B

    2012-01-01

    A total of 602 samples of organically and conventionally grown barley, oats and wheat was collected at grain harvest during 2002-2004 in Norway. Organic and conventional samples were comparable pairs regarding cereal species, growing site and harvest time, and were analysed for Fusarium mould and mycotoxins. Agronomic and climatic factors explained 10-30% of the variation in Fusarium species and mycotoxins. Significantly lower Fusarium infestation and concentrations of important mycotoxins were found in the organic cereals. The mycotoxins deoxynivalenol (DON) and HT-2 toxin (HT-2) constitute the main risk for human and animal health in Norwegian cereals. The impacts of various agronomic and climatic factors on DON and HT-2 as well as on their main producers F. graminearum and F. langsethiae and on total Fusarium were tested by multivariate statistics. Crop rotation with non-cereals was found to reduce all investigated characteristics significantly--mycotoxin concentrations as well as various Fusarium infestations. No use of mineral fertilisers and herbicides was also found to decrease F. graminearum, whereas lodged fields increased the occurrence of this species. No use of herbicides was also found to decrease F. langsethiae, but for this species the occurrence was lower in lodged fields. Total Fusarium infestation was decreased with no use of fungicides or mineral fertilisers, and with crop rotation, as well as by using herbicides and increased by lodged fields. Clay and to some extent silty soils seemed to reduce F. graminearum in comparison with sandy soils. Concerning climate factors, low temperature before grain harvest was found to increase DON; and high air humidity before harvest to increase HT-2. F. graminearum was negatively correlated with precipitation in July but correlated with air humidity before harvest. F. langsethiae was correlated with temperature in July. Total Fusarium increased with increasing precipitation in July. Organic cereal farmers have

  18. Effect of particle size and microbial phytase on phytate degradation in incubated maize and soybean meal.

    PubMed

    Ton Nu, M A; Blaabjerg, K; Poulsen, H D

    2014-04-01

    The objective of the study was to evaluate the effect of screen size (1, 2 and 3 mm) and microbial phytase (0 and 1000 FTU/kg as-fed) on phytate degradation in maize (100% maize), soybean meal (100% SBM) and maize-SBM (75% maize and 25% SBM) incubated in water for 0, 2, 4, 8 and 24 h at 38°C. Samples were analysed for pH, dry matter and phytate phosphorus (P). Particle size distribution (PSD) and average particle size (APS) of samples were measured by the Laser Diffraction and Bygholm method. PSD differed between the two methods, whereas APS was similar. Decreasing screen size from 3 to 1 mm reduced APS by 48% in maize, 30% in SBM and 26% in maize-SBM. No interaction between screen size and microbial phytase on phytate degradation was observed, but the interaction between microbial phytase and incubation time was significant ( P<0.001). This was because microbial phytase reduced phytate P by 88% in maize, 84% in maize-SBM and 75% in SBM after 2 h of incubation ( P<0.05), whereas the reduction of phytate P was limited (<50%) in the feeds, even after 24 h when no microbial phytase was added. The exponential decay model was fitted to the feeds with microbial phytase to analyse the effect of screen size and feed on microbial phytase efficacy on phytate degradation. The interaction between screen size and feed affected the relative phytate degradation rate ( Rd) of microbial phytase as well as the time to decrease 50% of the phytate P ( t1 =2) ( P<0.001). Thus, changing from 3 to 1 mm screen size increased Rd by 22 and 10%/h and shortened t1 =2 by 0.4 and 0.2 h in maize and maize-SBM, respectively ( P<0.05), but not in SBM. Moreover, the screen size effect was more pronounced in maize and maize-SBM compared with SBM as a higher phytate degradation rate constant (Kd) and Rd, and a shorter t1 =2 was observed in maize compared with SBM in all screen sizes ( P<0.05). However, a higher amount of degraded phytate was achieved in SBM than in maize because of the higher

  19. Modelling of maize production in Croatia: present and future climate.

    PubMed

    Vučetić, V

    2011-04-01

    Maize is one of the most important agricultural crops in Croatia, and was selected for research of the effect of climate warming on yields. The Decision Support System for the Agrotechnology Transfer model (DSSAT) is one of the most utilized crop-weather models in the world, and was used in this paper for the investigation of maize growth and production in the present and future climate. The impact of present climate on maize yield was studied using DSSAT 4.0 with meteorological data from the Zagreb-Maksimir station covering the period 1949-2004. Pedological, physiological and genetic data from a 1999 field maize experiment at the same location were added. The location is representative of the continental climate in central Croatia. The linear trends of model outputs and the non-parametric Mann-Kendall test indicate that the beginning of silking has advanced significantly by 1·4 days/decade since the mid-1990s, and maturity by 4·5 days/decade. It also shows a decrease in biomass by 122 kg/ha and in maize yield by 216 kg/ha in 10 years.Estimates of the sensitivity of maize growth and yield in future climates were made by changing the initial weather and CO(2) conditions of the DSSAT 4.0 model according to the different climatic scenarios for Croatia at the end of the 21st century. Changed climate suggests increases in global solar radiation, minimal temperature and maximal temperature (×1·07, 2 and 4°C, respectively), but a decrease in the amount of precipitation (×0·92), compared with weather data from the period 1949-2004. The reduction of maize yield was caused by the increase in minimal and maximal temperature and the decrease in precipitation amount, related to the present climate, is 6, 12 and 3%, respectively. A doubling of CO(2) concentration stimulates leaf assimilation, but maize yield is only 1% higher, while global solar radiation growth by 7% increases evapotranspiration by 3%. Simultaneous application of all these climate changes suggested that

  20. Modelling of maize production in Croatia: present and future climate

    PubMed Central

    VUČETIĆ, V.

    2011-01-01

    SUMMARY Maize is one of the most important agricultural crops in Croatia, and was selected for research of the effect of climate warming on yields. The Decision Support System for the Agrotechnology Transfer model (DSSAT) is one of the most utilized crop–weather models in the world, and was used in this paper for the investigation of maize growth and production in the present and future climate. The impact of present climate on maize yield was studied using DSSAT 4.0 with meteorological data from the Zagreb–Maksimir station covering the period 1949–2004. Pedological, physiological and genetic data from a 1999 field maize experiment at the same location were added. The location is representative of the continental climate in central Croatia. The linear trends of model outputs and the non-parametric Mann–Kendall test indicate that the beginning of silking has advanced significantly by 1·4 days/decade since the mid-1990s, and maturity by 4·5 days/decade. It also shows a decrease in biomass by 122 kg/ha and in maize yield by 216 kg/ha in 10 years. Estimates of the sensitivity of maize growth and yield in future climates were made by changing the initial weather and CO2 conditions of the DSSAT 4.0 model according to the different climatic scenarios for Croatia at the end of the 21st century. Changed climate suggests increases in global solar radiation, minimal temperature and maximal temperature (×1·07, 2 and 4°C, respectively), but a decrease in the amount of precipitation (×0·92), compared with weather data from the period 1949–2004. The reduction of maize yield was caused by the increase in minimal and maximal temperature and the decrease in precipitation amount, related to the present climate, is 6, 12 and 3%, respectively. A doubling of CO2 concentration stimulates leaf assimilation, but maize yield is only 1% higher, while global solar radiation growth by 7% increases evapotranspiration by 3%. Simultaneous application of all these climate changes

  1. Maize rhabdovirus-vector transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    oth of the plant-infecting rhabdovirus genera, Nucleorhabdovirus and Cytorhabdovirus, contain viruses that infect maize (Zea mays L.). The maize infecting rhabdoviruses are transmitted by hemipteran insects in the families Cicadellidae and Delphacidae in a persistent propagative manner. This chapt...

  2. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is provided each year to our stakeholders in the maize genetic community. In this report, we describe the five-year plan for MaizeGDB reviewed in early 2008 by the USDA-ARS peer review process and which was developed with inputs from our Working Group and the Allerton 2007 Report (MNL 82...

  3. The agronomic science of spatial and temporal water management:How much, when and where

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agronomic sciences are those that are applied to soil and water management and crop production, including soil, water and plant sciences and related disciplines. The science of spatial and temporal water management includes many agronomic science factors, including soil physics, biophysics, plan...

  4. Retention of agronomically important variation in germplasm core collections: implications for allele mining

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary targets of allele mining efforts are loci of agronomic importance. Agronomic loci typically exhibit patterns of allelic diversity consistent with a history of natural or artificial selection. Natural or artificial selection causes the distribution of genetic diversity at such loci to d...

  5. The MaizeGDB Genome Browser

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of an effort to develop MaizeGDB as a more sequence-centric resource, we implemented a genome browser based on information we gathered by surveying the community of maize geneticists. Based on commu...

  6. Metabolic pathway resources at MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two maize metabolic networks are available at MaizeGDB: MaizeCyc (http://maizecyc.maizegdb.org, also at Gramene) and CornCyc (http://corncyc.maizegdb.org, also at the Plant Metabolic Network). MaizeCyc was developed by Gramene, and CornCyc by the Plant Metabolic Network, both in collaboration with M...

  7. Maize variety and method of production

    DOEpatents

    Pauly, Markus; Hake, Sarah; Kraemer, Florian J

    2014-05-27

    The disclosure relates to a maize plant, seed, variety, and hybrid. More specifically, the disclosure relates to a maize plant containing a Cal-1 allele, whose expression results in increased cell wall-derived glucan content in the maize plant. The disclosure also relates to crossing inbreds, varieties, and hybrids containing the Cal-1 allele to produce novel types and varieties of maize plants.

  8. Agronomic, metabolomic and lipidomic characterisation of Sicilian Origanum vulgare (L.) ecotypes.

    PubMed

    Tuttolomondo, Teresa; Martinelli, Federico; Mariotti, Lorenzo; Leto, Claudio; Maggio, Antonella; La Bella, Salvatore

    2016-01-01

    Although Origanum vulgare (L.) has been deeply analysed at phytochemical level, poor knowledge is available regarding non-volatile compounds such as lipids. The aim of this work was to characterise five wild Sicilian Origanum ecotypes from an agronomic, metabolomic and lipidomic perspective. Serradifalco presented higher dry weight and inflorescences/plant than the others while Favara had a significantly higher number of branches per plant and more extensive flowered stratum. Metabolomic analysis, performed with LC-MS-TOF, allowed a preliminary characterisation of the non-volatile metabolome of the five oregano ecotypes Origanum vulgare ssp. hirtum. Twenty-five metabolites were identified belonging to organic acids, amino acids, lysophosphatidylcholines, carnithines, nucleic bases and lysophosphatidylethanolamines. Lipidomic analysis identified 115 polar plant membrane glycerolipid species. Thirteen of them were differentially present in the two chosen ecotypes. The role of these metabolites in plant physiology from a qualitative and pharmacological point of view was discussed.

  9. Diversity of Fusarium species isolated from UK forage maize and the population structure of F. graminearum from maize and wheat

    PubMed Central

    2016-01-01

    Pre-harvest contamination of forage maize by mycotoxin producing Fusarium species was investigated in the UK in 2011 and 2012. A total of 15 Fusarium species were identified from a collection of 1,761 Fusarium isolates recovered from maize stalks and kernels. This study characterized the diversity of Fusarium species present in forage maize in the UK. The predominant species detected were F. graminearum (32.9%) and F. culmorum (34.1%). Along with those species; F. avenacem, F. cerealis, F. equiseti, F. langsethiae, F. napiforme, F. oxysporum, F. poae, F. proliferatum, F. scripi, F. solani, F. subglutinans, F. tricinctum and, F. verticillioides were occasionally isolated. The trichothecene genotypes for F. graminearum were determined to be 84.9% deoxynivalenol (DON) and 15.0% nivalenol (NIV) while F. culmorum isolates were determined to have 24.9% DON and 75.1% NIV genotypes. A Bayesian model-based clustering method with nine variable number of tandem repeat markers was used to evaluate the population genetic structure of 277 F. graminearum isolates from the maize and wheat in the UK. There were three genetic clusters detected which were DON in maize, NIV in maize and DON in wheat. There were high admixture probabilities for 14.1% of the isolates in the populations. In conclusion, increased maize production in the UK and the high admixture rates in a significant portion of F. graminearum populations in maize and wheat will contribute to a new pathogen population which will further complicate breeding strategies for tolerance or resistance to this pathogen in both crops. PMID:27366645

  10. Diversity of Fusarium species isolated from UK forage maize and the population structure of F. graminearum from maize and wheat.

    PubMed

    Basler, Ryan

    2016-01-01

    Pre-harvest contamination of forage maize by mycotoxin producing Fusarium species was investigated in the UK in 2011 and 2012. A total of 15 Fusarium species were identified from a collection of 1,761 Fusarium isolates recovered from maize stalks and kernels. This study characterized the diversity of Fusarium species present in forage maize in the UK. The predominant species detected were F. graminearum (32.9%) and F. culmorum (34.1%). Along with those species; F. avenacem, F. cerealis, F. equiseti, F. langsethiae, F. napiforme, F. oxysporum, F. poae, F. proliferatum, F. scripi, F. solani, F. subglutinans, F. tricinctum and, F. verticillioides were occasionally isolated. The trichothecene genotypes for F. graminearum were determined to be 84.9% deoxynivalenol (DON) and 15.0% nivalenol (NIV) while F. culmorum isolates were determined to have 24.9% DON and 75.1% NIV genotypes. A Bayesian model-based clustering method with nine variable number of tandem repeat markers was used to evaluate the population genetic structure of 277 F. graminearum isolates from the maize and wheat in the UK. There were three genetic clusters detected which were DON in maize, NIV in maize and DON in wheat. There were high admixture probabilities for 14.1% of the isolates in the populations. In conclusion, increased maize production in the UK and the high admixture rates in a significant portion of F. graminearum populations in maize and wheat will contribute to a new pathogen population which will further complicate breeding strategies for tolerance or resistance to this pathogen in both crops.

  11. Safety assessment of Bt 176 maize in broiler nutrition: degradation of maize-DNA and its metabolic fate.

    PubMed

    Tony, M A; Butschke, A; Broll, H; Grohmann, L; Zagon, J; Halle, I; Dänicke, S; Schauzu, M; Hafez, H M; Flachowsky, G

    2003-08-01

    Insect resistant Bt 176 maize has been developed by genetic modification to resist European borer infection. In the present investigation, the experiment was conducted to determine the effect of feeding a new hybrid of Bt 176 maize (NX 6262- Bt 176) on general health condition and performance of broiler chickens. Maize grains and diets were subjected to proximate analysis. Amino and fatty acids investigation were applied for both maize grains before used. To evaluate the degradation of NX 6262- Bt 176 maize DNA and its metabolic fate in broiler blood, muscles and organs. One-day-old male broilers were fed ad libitum on either an experimental diet containing NX 6262- Bt 176 or a control diet containing the non-modified maize grains for 35 days. Feed consumption and body weight were recorded weekly during the experimental period. All chickens were subjected to nutritional evaluation period at day 20 of age for 5 successive days, to calculate the percentage of apparent digestible nutrients in both diets. At day 35 samples were collected at several intervals after feed withdrawal. Prior to slaughter blood samples were collected from all birds by heart puncture to prevent DNA cross contamination. Samples from pectoral and thigh muscles, liver, spleen, kidney, heart muscle, bursa and thymus glands were collected. Digesta from different sections of the gastrointestinal tract (GIT) were collected as well. Packed cell volume (PCV) and some serum parameters were investigated. There were no significant differences between control and experimental group concerning chemical composition of feeds, apparent digestible nutrients, and all performance parameters measured (P > 0.05). Furthermore, there were no differences in the PCV and the analysed serum parameters between the control and experimental group. The results of maize DNA digestibility showed that the new variety takes the normal physiological passage along broiler GIT similar to the conventional line. In addition, Bt 176

  12. Use of morpho-agronomic traits and DNA profiling for classification of genetic diversity in papaya.

    PubMed

    de Jesus, O N; de Freitas, J P X; Dantas, J L L; de Oliveira, E J

    2013-03-11

    We examined the genetic diversity of papaya (Carica papaya) based on morpho-agronomic and molecular data. Twenty-seven genotypes grown in Brazil were analyzed with 11 AFLP primer combinations, 23 ISSR markers, 22 qualitative, and 30 quantitative descriptors. For the joint analyses, we used the Gower algorithm (Joint Gower) and the average value of the individual dissimilarity matrix for each type of data (Average-Joint Gower); 359 AFLP and 52 ISSR polymorphic bands were found. Approximately 29.2 and 7.7% of the AFLP and ISSR bands, respectively, were genotype-specific and may therefore be used for papaya variety protection. Although there was a significant correlation between the qualitative and quantitative descriptor dissimilarity matrices (r = 0.43), the morpho-agronomic data were not highly correlated with the molecular data. Moreover, correlation between AFLP and ISSR dissimilarity matrices was nearly null (r = -0.01). Joint Gower analysis of all data showed high correlations, especially for AFLP markers, most likely due to the larger number of bands, generating a strong bias in the diversity estimates. The Average-Joint Gower analysis allowed a better balance between the correlations for the continuous and the discrete variables. The results generated by clustering analysis distinguished 5 genetically distinct groups. While we found that papaya genotypes are significantly variable for many traits, we observed that Average-Joint Gower analysis allowed for genotype clustering based on the most widely used criterion for classifying papaya genotypes, which is fruit type ('Formosa' or 'Solo'). This information helps provide an accurate estimate of the genetic diversity and structure of papaya germplasm, which will be used for further breeding strategies.

  13. A long-term nitrogen fertilizer gradient has little effect on soil organic matter in a high-intensity maize production system.

    PubMed

    Brown, Kimberly H; Bach, Elizabeth M; Drijber, Rhae A; Hofmockel, Kirsten S; Jeske, Elizabeth S; Sawyer, John E; Castellano, Michael J

    2014-04-01

    Global maize production alters an enormous soil organic C (SOC) stock, ultimately affecting greenhouse gas concentrations and the capacity of agroecosystems to buffer climate variability. Inorganic N fertilizer is perhaps the most important factor affecting SOC within maize-based systems due to its effects on crop residue production and SOC mineralization. Using a continuous maize cropping system with a 13 year N fertilizer gradient (0-269 kg N ha(-1) yr(-1)) that created a large range in crop residue inputs (3.60-9.94 Mg dry matter ha(-1) yr(-1)), we provide the first agronomic assessment of long-term N fertilizer effects on SOC with direct reference to N rates that are empirically determined to be insufficient, optimum, and excessive. Across the N fertilizer gradient, SOC in physico-chemically protected pools was not affected by N fertilizer rate or residue inputs. However, unprotected particulate organic matter (POM) fractions increased with residue inputs. Although N fertilizer was negatively linearly correlated with POM C/N ratios, the slope of this relationship decreased from the least decomposed POM pools (coarse POM) to the most decomposed POM pools (fine intra-aggregate POM). Moreover, C/N ratios of protected pools did not vary across N rates, suggesting little effect of N fertilizer on soil organic matter (SOM) after decomposition of POM. Comparing a N rate within 4% of agronomic optimum (208 kg N ha(-1) yr(-1)) and an excessive N rate (269 kg N ha(-1) yr(-1)), there were no differences between SOC amount, SOM C/N ratios, or microbial biomass and composition. These data suggest that excessive N fertilizer had little effect on SOM and they complement agronomic assessments of environmental N losses, that demonstrate N2 O and NO3 emissions exponentially increase when agronomic optimum N is surpassed.

  14. Determination of carotenoids in yellow maize, the effects of saponification and food preparations.

    PubMed

    Muzhingi, Tawanda; Yeum, Kyung-Jin; Russell, Robert M; Johnson, Elizabeth J; Qin, Jian; Tang, Guangwen

    2008-05-01

    Maize is an important staple food consumed by millions of people in many countries. Yellow maize naturally contains carotenoids which not only provide provitamin A carotenoids but also xanthophylls, which are known to be important for eye health. This study was aimed at 1) evaluating the effect of saponification during extraction of yellow maize carotenoids, 2) determining the major carotenoids in 36 genotypes of yellow maize by high-performance liquid chromatography with a C30 column, and 3) determining the effect of cooking on the carotenoid content of yellow maize. The major carotenoids in yellow maize were identified as all-trans lutein, cis-isomers of lutein, all-trans zeaxanthin, alpha- and beta-cryptoxanthin, all-trans beta-carotene, 9-cis beta-carotene, and 13-cis beta-carotene. Our results indicated that carotenoid extraction without saponification showed a significantly higher yield than that obtained using saponification. Results of the current study indicate that yellow maize is a good source of provitamin A carotenoids and xanthophylls. Cooking by boiling yellow maize at 100 degrees C for 30 minutes increased the carotenoid concentration, while baking at 450 degrees F for 25 minutes decreased the carotenoid concentrations by almost 70% as compared to the uncooked yellow maize flour.

  15. Stability of key micronutrients added to fortified maize flours and corn meal.

    PubMed

    Dunn, Michael L; Jain, Vijaya; Klein, Barbara P

    2014-04-01

    Maize is a dietary staple in many countries. Although nutritious in many ways and a good source of energy, typical maize lacks several key micronutrients (MNs) that are often added to maize meals or flours to enhance nutritional value. Many factors affect MN stability in maize products, including uncontrolled conditions during distribution, long storage times, and MN premix composition. Consumer preparation also affects the final MN content of food. This review summarizes research relating to MN stability during processing, transport, storage, and meal preparation, focusing on those MNs most often added to maize and maize-based foods. Significant losses in B vitamins (B1, B2, B3, B6, B9, and B12) occur during manufacturing, distribution, and cooking. Added minerals (e.g., iron, zinc, calcium) are generally retained, although phytates in corn may affect bioavailability. Vitamins A and D3 are recent additions to fortification premixes for maize and are not well studied. Although there have been numerous studies of MN fortification in wheat flour, maize has not been as thoroughly examined, so recommendations are not as well supported. Future investigations should include well-designed and executed studies of the most labile MNs added to maize flours and meals, and their fate during all steps of processing, shipping, and preparation. PMID:24329721

  16. Genetic Analysis in Maize Foundation Parents with Mapping Population and Testcross Population: Ye478 Carried More Favorable Alleles and Using QTL Information Could Improve Foundation Parents

    PubMed Central

    Liu, Yinghong; Hou, Xianbin; Xiao, Qianlin; Yi, Qiang; Bian, Shaowei; Hu, Yufeng; Liu, Hanmei; Zhang, Junjie; Hao, Xiaoqin; Cheng, Weidong; Li, Yu; Huang, Yubi

    2016-01-01

    The development of maize foundation parents is an important part of genetics and breeding research, and applying new genetic information to produce foundation parents has been challenging. In this study, we focused on quantitative trait loci (QTLs) and general combining ability (GCA) of Ye478, a widely used foundation parent in China. We developed three sets of populations for QTL mapping and to analyze the GCA for some agronomic traits. The assessment of 15 traits resulted in the detection of 251 QTLs in six tested environments, with 119 QTLs identified through a joint analysis across all environments. Further, analyses revealed that most favorable alleles for plant type-related traits were from Ye478, and more than half of the favorable alleles for yield-related traits were from R08, another foundation parent used in southwestern China, suggesting that different types of foundation parents carried different favorable alleles. We observed that the GCA for most traits (e.g., plant height and 100-kernel weight) was maintained in the inbred lines descended from the foundation parents. Additionally, the continuous improvement in the GCA of the descendants of the foundation parents was consistent with the main trend in maize breeding programs. We identified three significant genomic regions that were highly conserved in three Ye478 descendants, including the stable QTL for plant height. The GCA for the traits in the F7 generation revealed that the QTLs for the given traits per se were affected by additive effects in the same way in different populations. PMID:27721817

  17. Aflatoxin Control in Maize by Trametes versicolor

    PubMed Central

    Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A.; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

    2014-01-01

    Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1. PMID:25525683

  18. Field screening of maize germplasm lines for whorl-feeding fall armyworm resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new set of 13 maize germplasm lines from the Germplasm Enhancement of Maize (GEM) Program was examined with 5 controls that have different degrees of insect resistance. Significant difference in fall armyworm damage ratings was detected among the GEM inbred lines. In addition, the total number of ...

  19. Comparison of nine PCR primer sets designed to detect Pantoea stewartii subsp. stewartii in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea stewartii subsp. stewartii, the causal agent of Stewart's bacterial wilt of maize, is a major quarantine pest in maize seed. Verifying freedom from P. stewartii remains a significant hurdle in exporting corn seed from the U.S. Several PCR primer sets have been developed and suggested as bein...

  20. The Phosphorus Transfer From Soil To Water As Affected By The Agronomic Management

    NASA Astrophysics Data System (ADS)

    Borda, Teresa; Celi, Luisella; Buenemann, Else; Oberson, Astrid; Frossard, Emmanuel; Barberis, Elisabetta

    2010-05-01

    Fertilizer management, in the long term, can affect the amount of P that can be in excess compared to the cultural needs and modify the soil P buffer capacity. These factors can led to P losses from soil to waters, especially via runoff and as particulate P (90% of TP). Soil texture and the amount of organic matter are the main key factors to estimate soil disperdibility but, in turn, the P amount and its forms can also have a dispersive effect and can influence P enrichment of particles potentially lost during runoff processes and its contribution to water eutrophication. The environmental impact due to the P transfer depends on P speciation, because only the inorganic and soluble P forms, or the most degradable organic P ones, are bioavailable. To evaluate the effect of agronomic practices on P losses and on its bioavailability in the long term, soil samples from a middle term experiment have been selected. The field experiment is based on maize cropping systems applying different fertilizers, mineral, as NPK and PK, and organic, as manure (M) and slurry (S) since 1992. To obtain the suspended sediment from soil, a simple water dispersion test was applied (Withers et al., 2007) and the different P forms were characterized. On soil and on suspended sediment the Hedley fractionation (Hedley et al., 1982) was used to determine the P forms, their potential lability and the effect on soil disperdibility. The adoption of isotopic techniques was considered to compare different methods and to estimate the risk of P losses in the long-term. Dispersion test, to simulate the rainy event and the irrigation practices effect on soil, showed that the amount of total suspended sediment lost (TSS) was lower in the organic fertilized plots, while the particulate P bounded to sediment (PP/TSS) was higher than in the mineral fertilized plots. Indeed the complexive effect of organic fertilization, increasing organic matter content and Olsen P, was reflected in a lower soil

  1. Intraspecific variation of recombination rate in maize

    PubMed Central

    2013-01-01

    Background In sexually reproducing organisms, meiotic crossovers ensure the proper segregation of chromosomes and contribute to genetic diversity by shuffling allelic combinations. Such genetic reassortment is exploited in breeding to combine favorable alleles, and in genetic research to identify genetic factors underlying traits of interest via linkage or association-based approaches. Crossover numbers and distributions along chromosomes vary between species, but little is known about their intraspecies variation. Results Here, we report on the variation of recombination rates between 22 European maize inbred lines that belong to the Dent and Flint gene pools. We genotype 23 doubled-haploid populations derived from crosses between these lines with a 50 k-SNP array and construct high-density genetic maps, showing good correspondence with the maize B73 genome sequence assembly. By aligning each genetic map to the B73 sequence, we obtain the recombination rates along chromosomes specific to each population. We identify significant differences in recombination rates at the genome-wide, chromosome, and intrachromosomal levels between populations, as well as significant variation for genome-wide recombination rates among maize lines. Crossover interference analysis using a two-pathway modeling framework reveals a negative association between recombination rate and interference strength. Conclusions To our knowledge, the present work provides the most comprehensive study on intraspecific variation of recombination rates and crossover interference strength in eukaryotes. Differences found in recombination rates will allow for selection of high or low recombining lines in crossing programs. Our methodology should pave the way for precise identification of genes controlling recombination rates in maize and other organisms. PMID:24050704

  2. Seed-Specific Expression of the Arabidopsis AtMAP18 Gene Increases both Lysine and Total Protein Content in Maize

    PubMed Central

    Chang, Yujie; Shen, Erli; Wen, Liuying; Yu, Jingjuan; Zhu, Dengyun; Zhao, Qian

    2015-01-01

    Lysine is the most limiting essential amino acid for animal nutrition in maize grains. Expression of naturally lysine-rich protein genes can increase the lysine and protein contents in maize seeds. AtMAP18 from Arabidopsis thaliana encoding a microtubule-associated protein with high-lysine content was introduced into the maize genome with the seed-specific promoter F128. The protein and lysine contents of different transgenic offspring were increased prominently in the six continuous generations investigated. Expression of AtMAP18 increased both zein and non-zein protein in the transgenic endosperm. Compared with the wild type, more protein bodies were observed in the endosperm of transgenic maize. These results implied that, as a cytoskeleton binding protein, AtMAP18 facilitated the formation of protein bodies, which led to accumulation of both zein and non-zein proteins in the transgenic maize grains. Furthermore, F1 hybrid lines with high lysine, high protein and excellent agronomic traits were obtained by hybridizing T6 transgenic offspring with other wild type inbred lines. This article provides evidence supporting the use of cytoskeleton-associated proteins to improve the nutritional value of maize. PMID:26580206

  3. Sewage sludge hydrochars: properties and agronomic impact as related to different production conditions

    NASA Astrophysics Data System (ADS)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Conte, Pellegrino; Knicker, Heike

    2015-04-01

    amount of hydrochar equivalent to 5 and 25 t ha-1 were prepared in quadruplicate for each hydrochar using Lolium perenne as test plant (25 seeds per pot). Hydrochars were not washed before this experiment. Control pots, without hydrochar amendment, were also settled for comparison purposes (n=6). After adjusting the soil humidity to 60% of the maximum WHC, the pots were placed into a greenhouse under similar conditions than those reported by [3]. In this experiment germination, survival rates and biomass production per pot were measured periodically. Elemental analysis and the determination of several chemical properties of hydrochars such as pH, electrical conductivity and ash content were performed. Additionally, 13C solid-state nuclear magnetic resonance (NMR) was applied to elucidate the main chemical groups whereas fast field cycling (FFC) NMR relaxometry was valuable for investigating the porous structure and water dynamic in the different hydrochars. This work confirmed that production conditions of hydrochars vary their chemical properties and hence their agronomic effect. Biomass production raised significantly in presence of all hydrochars, being the response in presence of hydrochars produced at 200˚C significantly higher than the response in presence of hydrochars produced at 260˚C, whereas the residence time of the hydrochars in the reactor did not affect biomass productivity. Concerning the characterization data, hydrochars which showed the highest biomass production were those which contain the highest mineralized nitrogen content (NH4, NO2 and NO3) and a greater presence of alkyl carbons and carboxyl groups. Hydrochars FFC NMR relaxometry results show a lower T1 (longitudinal relaxation time) compared to the pure sewage sludge, which suggests that HTC processes reduced the average pore size of the system. This has further implications in the water and nutrient retention capacity of the hydrochars compared to the pure sewage sludge. Acknowledgements: The

  4. Agronomic conditions and crop evolution in ancient Near East agriculture

    PubMed Central

    Aguilera, Mònica; Buxó, Ramón

    2014-01-01

    The appearance of agriculture in the Fertile Crescent has propelled the development of Western civilization. Here we investigate the evolution of agronomic conditions in this region by reconstructing cereal kernel weight and using stable carbon and nitrogen isotope signatures of kernels and charcoal from a set of 11 Upper Mesopotamia archaeological sites, with chronologies spanning from the onset of agriculture to the turn of the era. We show that water availability for crops, inferred from carbon isotope discrimination (Δ13C), was two- to fourfold higher in the past than at present, with a maximum between 10,000 and 8,000 cal BP. Nitrogen isotope composition (δ15N) decreased over time, which suggests cultivation occurring under gradually less fertile soil conditions. Domesticated cereals showed a progressive increase in kernel weight over several millennia following domestication. Our results provide a first comprehensive view of agricultural evolution in the Near East inferred directly from archaeobotanical remains. PMID:24853475

  5. Agronomic conditions and crop evolution in ancient Near East agriculture.

    PubMed

    Araus, José L; Ferrio, Juan P; Voltas, Jordi; Aguilera, Mònica; Buxó, Ramón

    2014-05-23

    The appearance of agriculture in the Fertile Crescent propelled the development of Western civilization. Here we investigate the evolution of agronomic conditions in this region by reconstructing cereal kernel weight and using stable carbon and nitrogen isotope signatures of kernels and charcoal from a set of 11 Upper Mesopotamia archaeological sites, with chronologies spanning from the onset of agriculture to the turn of the era. We show that water availability for crops, inferred from carbon isotope discrimination (Δ(13)C), was two- to fourfold higher in the past than at present, with a maximum between 10,000 and 8,000 cal BP. Nitrogen isotope composition (δ(15)N) decreased over time, which suggests cultivation occurring under gradually less-fertile soil conditions. Domesticated cereals showed a progressive increase in kernel weight over several millennia following domestication. Our results provide a first comprehensive view of agricultural evolution in the Near East inferred directly from archaeobotanical remains.

  6. Agronomic conditions and crop evolution in ancient Near East agriculture.

    PubMed

    Araus, José L; Ferrio, Juan P; Voltas, Jordi; Aguilera, Mònica; Buxó, Ramón

    2014-01-01

    The appearance of agriculture in the Fertile Crescent propelled the development of Western civilization. Here we investigate the evolution of agronomic conditions in this region by reconstructing cereal kernel weight and using stable carbon and nitrogen isotope signatures of kernels and charcoal from a set of 11 Upper Mesopotamia archaeological sites, with chronologies spanning from the onset of agriculture to the turn of the era. We show that water availability for crops, inferred from carbon isotope discrimination (Δ(13)C), was two- to fourfold higher in the past than at present, with a maximum between 10,000 and 8,000 cal BP. Nitrogen isotope composition (δ(15)N) decreased over time, which suggests cultivation occurring under gradually less-fertile soil conditions. Domesticated cereals showed a progressive increase in kernel weight over several millennia following domestication. Our results provide a first comprehensive view of agricultural evolution in the Near East inferred directly from archaeobotanical remains. PMID:24853475

  7. Spectral-agronomic relationships of corn, soybean and wheat canopies

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator); Daughtry, C. S. T.; Vanderbilt, V. C.

    1981-01-01

    During the past six years several thousand reflectance spectra of corn, soybean, and wheat canopies were acquired and analyzed. The relationships of biophysical variables, including leaf area index, percent soil cover, chlorophyll and water content, to the visible and infrared reflectance of canopies are described. The effects on reflectance of cultural, environmental, and stress factors such as planting data, seeding rate, row spacing, cultivar, soil type and nitrogen fertilization are also examined. The conclusions are that several key agronomic variables including leaf area index, development stage and degree of stress are strongly related to spectral reflectance and that it should be possible to estimate these descriptions of crop condition from satellite acquired multispectral data.

  8. Isolation and Characterization of Endophytic Colonizing Bacteria from Agronomic Crops and Prairie Plants†

    PubMed Central

    Zinniel, Denise K.; Lambrecht, Pat; Harris, N. Beth; Feng, Zhengyu; Kuczmarski, Daniel; Higley, Phyllis; Ishimaru, Carol A.; Arunakumari, Alahari; Barletta, Raúl G.; Vidaver, Anne K.

    2002-01-01

    Endophytic bacteria reside within plant hosts without causing disease symptoms. In this study, 853 endophytic strains were isolated from aerial tissues of four agronomic crop species and 27 prairie plant species. We determined several phenotypic properties and found approximately equal numbers of gram-negative and gram-positive isolates. In a greenhouse study, 28 of 86 prairie plant endophytes were found to colonize their original hosts at 42 days postinoculation at levels of 3.5 to 7.7 log10 CFU/g (fresh weight). More comprehensive colonization studies were conducted with 373 corn and sorghum endophytes. In growth room studies, none of the isolates displayed pathogenicity, and 69 of the strains were recovered from corn or sorghum seedlings at levels of 8.3 log10 CFU/plant or higher. Host range greenhouse studies demonstrated that 26 of 29 endophytes were recoverable from at least one host other than corn and sorghum at levels of up to 5.8 log10 CFU/g (fresh weight). Long-range dent corn greenhouse studies and field trials with 17 wild-type strains and 14 antibiotic-resistant mutants demonstrated bacterial persistence at significant average colonization levels ranging between 3.4 and 6.1 log10 CFU/g (fresh weight) up to 78 days postinoculation. Three prairie and three agronomic endophytes exhibiting the most promising levels of colonization and an ability to persist were identified as Cellulomonas, Clavibacter, Curtobacterium, and Microbacterium isolates by 16S rRNA gene sequence, fatty acid, and carbon source utilization analyses. This study defines for the first time the endophytic nature of Microbacterium testaceum. These microorganisms may be useful for biocontrol and other applications. PMID:11976089

  9. Functional properties of selected starter cultures for sour maize bread.

    PubMed

    Edema, Mojisola O; Sanni, Abiodun I

    2008-06-01

    This paper focuses on the functional properties of maize sour-dough microflora selected and tested for their use as starter cultures for sour maize bread. Lactic acid bacteria and yeasts isolated from spontaneously fermented maize dough were selected based on dominance during fermentation and presence at the end of fermentation. Functional properties examined included acidification, leavening and production of some antimicrobial compounds in the fermenting matrix. The organisms previously identified as Lactobacillus plantarum, Lb. brevis, Lb. fermentum, Lb. acidophilus, Pediococcus acidilactici, Leuconostoc mesenteroides and Leuconostoc dextranicum and Saccharomyces cerevisiae were used singly and as mixed cultures in the fermentation (fermentation time: 12h at 28+/-2 degrees C) of maize meal (particle size >0.2mm). The pH fell from an initial value of 5.62-3.05 in maize meals fermented with Lb. plantarum; 4.37 in L. dextranicum+S. cerevisiae compared with the value for the control (no starter) of 4.54. Significant differences (P significant correlations existed among pH and production of antimicrobial compounds in the fermenting meals, the highest correlation being between production of diacetyl and acid (0.694), a positive correlation indicating that production of both antimicrobial compounds increase together with time. Antimicrobial activities of the fermented maize dough were confirmed by their abilities to inhibit the growth of Salmonella typhi, Escherichia coli, Staphylococcus aureus and Aspergillus flavus from an initial inoculum concentration of 7 log cfu ml(-1)) for test bacteria and zone of inhibition of up to 1.33 cm for aflatoxigenic A. flavus. The findings of this study form a database for further studies on the

  10. Gene Expression Biomarkers Provide Sensitive Indicators of in Planta Nitrogen Status in Maize[W][OA

    PubMed Central

    Yang, Xiaofeng S.; Wu, Jingrui; Ziegler, Todd E.; Yang, Xiao; Zayed, Adel; Rajani, M.S.; Zhou, Dafeng; Basra, Amarjit S.; Schachtman, Daniel P.; Peng, Mingsheng; Armstrong, Charles L.; Caldo, Rico A.; Morrell, James A.; Lacy, Michelle; Staub, Jeffrey M.

    2011-01-01

    Over the last several decades, increased agricultural production has been driven by improved agronomic practices and a dramatic increase in the use of nitrogen-containing fertilizers to maximize the yield potential of crops. To reduce input costs and to minimize the potential environmental impacts of nitrogen fertilizer that has been used to optimize yield, an increased understanding of the molecular responses to nitrogen under field conditions is critical for our ability to further improve agricultural sustainability. Using maize (Zea mays) as a model, we have characterized the transcriptional response of plants grown under limiting and sufficient nitrogen conditions and during the recovery of nitrogen-starved plants. We show that a large percentage (approximately 7%) of the maize transcriptome is nitrogen responsive, similar to previous observations in other plant species. Furthermore, we have used statistical approaches to identify a small set of genes whose expression profiles can quantitatively assess the response of plants to varying nitrogen conditions. Using a composite gene expression scoring system, this single set of biomarker genes can accurately assess nitrogen responses independently of genotype, developmental stage, tissue type, or environment, including in plants grown under controlled environments or in the field. Importantly, the biomarker composite expression response is much more rapid and quantitative than phenotypic observations. Consequently, we have successfully used these biomarkers to monitor nitrogen status in real-time assays of field-grown maize plants under typical production conditions. Our results suggest that biomarkers have the potential to be used as agronomic tools to monitor and optimize nitrogen fertilizer usage to help achieve maximal crop yields. PMID:21980173

  11. A rapid and efficient method for assessing pathogenicity of ustilago maydis on maize and teosinte lines.

    PubMed

    Chavan, Suchitra; Smith, Shavannor M

    2014-01-03

    Maize is a major cereal crop worldwide. However, susceptibility to biotrophic pathogens is the primary constraint to increasing productivity. U. maydis is a biotrophic fungal pathogen and the causal agent of corn smut on maize. This disease is responsible for significant yield losses of approximately $1.0 billion annually in the U.S.(1) Several methods including crop rotation, fungicide application and seed treatments are currently used to control corn smut(2). However, host resistance is the only practical method for managing corn smut. Identification of crop plants including maize, wheat, and rice that are resistant to various biotrophic pathogens has significantly decreased yield losses annually(3-5). Therefore, the use of a pathogen inoculation method that efficiently and reproducibly delivers the pathogen in between the plant leaves, would facilitate the rapid identification of maize lines that are resistant to U. maydis. As, a first step toward indentifying maize lines that are resistant to U. maydis, a needle injection inoculation method and a resistance reaction screening method was utilized to inoculate maize, teosinte, and maize x teosinte introgression lines with a U. maydis strain and to select resistant plants. Maize, teosinte and maize x teosinte introgression lines, consisting of about 700 plants, were planted, inoculated with a strain of U. maydis, and screened for resistance. The inoculation and screening methods successfully identified three teosinte lines resistant to U. maydis. Here a detailed needle injection inoculation and resistance reaction screening protocol for maize, teosinte, and maize x teosinte introgression lines is presented. This study demonstrates that needle injection inoculation is an invaluable tool in agriculture that can efficiently deliver U. maydis in between the plant leaves and has provided plant lines that are resistant to U. maydis that can now be combined and tested in breeding programs for improved disease resistance.

  12. Responses of stream macroinvertebrates to Bt maize leaf detritus.

    PubMed

    Chambers, Catherine P; Whiles, Matt R; Rosi-Marshall, Emma J; Tank, Jennifer L; Royer, Todd V; Griffiths, Natalie A; Evans-White, Michelle A; Stojak, Amber R

    2010-10-01

    In the midwestern United States, maize detritus enters streams draining agricultural land. Genetically modified Bt maize is commonly planted along streams and can possibly affect benthic macroinvertebrates, specifically members of the order Trichoptera, which are closely related to target species of some Bt toxins and are important detritivores in streams. The significance of inputs of Bt maize to aquatic systems has only recently been recognized, and assessments of potential nontarget impacts on aquatic organisms are lacking. We conducted laboratory feeding trials and found that the leaf-shredding trichopteran, Lepidostoma liba, grew significantly slower when fed Bt maize compared to non-Bt maize, while other invertebrate taxa that we examined showed no negative effects. We also used field studies to assess the influence of Bt maize detritus on benthic macroinvertebrate abundance, diversity, biomass, and functional structure in situ in 12 streams adjacent to Bt maize or non-Bt maize fields. We found no significant differences in total abundance or biomass between Bt and non-Bt streams, and trichopterans comprised only a small percentage of invertebrate biomass at all sites (0-15%). Shannon diversity did not differ among Bt and non-Bt streams and was always low (H' range = 0.9-1.9). Highly tolerant taxa, such as oligochaetes and chironomids, were dominant in both Bt and non-Bt streams, and macroinvertebrate community composition was relatively constant across seasons. We used litterbags to examine macroinvertebrate colonization of Bt and non-Bt maize detritus and found no significant differences among litter or stream types. Our in situ findings did not support our laboratory results; this is likely because the streams we studied in this region are highly degraded and subject to multiple, persistent anthropogenic stressors (e.g., channelization, altered flow, nutrient and pesticide inputs). Invertebrate communities in these streams are a product of these degraded

  13. Intraguild Competition of Three Noctuid Maize Pests.

    PubMed

    Bentivenha, J P F; Baldin, E L L; Hunt, T E; Paula-Moraes, S V; Blankenship, E E

    2016-08-01

    The western bean cutworm Striacosta albicosta (Smith), the fall armyworm Spodoptera frugiperda (J. E. Smith), and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) are among the major lepidopteran pests of maize in the United States, belonging to the same guild and injuring the reproductive tissues of this crop. Here, intraguild competition of these lepidopterans on non-Bt maize was evaluated through survival analysis of each species under laboratory and field conditions. Competition scenarios were carried out in arenas containing maize silk or ear tissue, using larvae on different stadium of development. Fitness cost competition studies were conducted to examine the influence of intraguild competition and cannibalism and predation rates on larval development. The survival of S. albicosta competing with the other species was significantly lower than in intraspecific competition, even when the larvae were more developed than the competitor. For S. frugiperda, survival remained high in the different competition scenarios, except when competing in a smaller stadium with H. zea Larvae of H. zea had a high rate of cannibalism, higher survival when competing against S. albicosta than S. frugiperda, and reduced survival when the H. zea larvae were at the same development stadium or smaller than the competitors. Based on fitness cost results, the absence of a competitor for the feeding source may confer an advantage to the larval development of S. frugiperda and H. zea Our data suggest that S. frugiperda has a competitive advantage against the other species, while S. albicosta has the disadvantage in the intraguild competition on non-Bt maize. PMID:27330146

  14. Intraguild Competition of Three Noctuid Maize Pests.

    PubMed

    Bentivenha, J P F; Baldin, E L L; Hunt, T E; Paula-Moraes, S V; Blankenship, E E

    2016-08-01

    The western bean cutworm Striacosta albicosta (Smith), the fall armyworm Spodoptera frugiperda (J. E. Smith), and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) are among the major lepidopteran pests of maize in the United States, belonging to the same guild and injuring the reproductive tissues of this crop. Here, intraguild competition of these lepidopterans on non-Bt maize was evaluated through survival analysis of each species under laboratory and field conditions. Competition scenarios were carried out in arenas containing maize silk or ear tissue, using larvae on different stadium of development. Fitness cost competition studies were conducted to examine the influence of intraguild competition and cannibalism and predation rates on larval development. The survival of S. albicosta competing with the other species was significantly lower than in intraspecific competition, even when the larvae were more developed than the competitor. For S. frugiperda, survival remained high in the different competition scenarios, except when competing in a smaller stadium with H. zea Larvae of H. zea had a high rate of cannibalism, higher survival when competing against S. albicosta than S. frugiperda, and reduced survival when the H. zea larvae were at the same development stadium or smaller than the competitors. Based on fitness cost results, the absence of a competitor for the feeding source may confer an advantage to the larval development of S. frugiperda and H. zea Our data suggest that S. frugiperda has a competitive advantage against the other species, while S. albicosta has the disadvantage in the intraguild competition on non-Bt maize.

  15. Analyses of sequence polymorphism and haplotype diversity of LEAFY genes revealed post-domestication selection in the Chinese elite maize inbred lines.

    PubMed

    Yang, Zefeng; Zhang, Enying; Li, Jing; Jiang, Ying; Wang, Yifan; Hu, Yunyun; Xu, Chenwu

    2014-02-01

    Post-domestication selection refers to the artificial selection on the loci controlling important agronomic traits during the process of genetic improvement in a population. The maize genes Zfl1 and Zfl2, duplicate orthologs of Arabidopsis LEAFY, are key regulators in plant branching, inflorescence and flower development, and reproduction. In this study, the full gene sequences of Zfl1 and Zfl2 from 62 Chinese elite inbred lines were amplified to evaluate their nucleotide polymorphisms and haplotype diversities. A total of 254 and 192 variants that included SNPs and indels were identified from the full sequences of Zfl1 and Zfl2, respectively. Although most of the variants were found to be located in the non-coding regions, the polymorphisms of CDS sequences classified Zfl1 into 16 haplotypes encoding 16 different proteins and Zfl2 into 18 haplotypes encoding eight different proteins. The population of Huangzaosi and its derived lines showed statistically significant signals of post-domestication selection on the Zfl1 CDS sequences, as well as lower nucleotide polymorphism and haplotype diversity than the whole set. However, the Zfl2 locus was only selected for in the heterotic group Reid. Further evidence revealed that at least 17 recombination events contributed to the genetic and haplotype diversities at the Zfl1 locus and 16 recombination events at the Zfl2 locus.

  16. The Maize Genetics and Genomics Database. The Community Resource for Access to Diverse Maize Data1

    PubMed Central

    Lawrence, Carolyn J.; Seigfried, Trent E.; Brendel, Volker

    2005-01-01

    The Maize Genetics and Genomics Database (MaizeGDB) serves the maize (Zea mays) research community by making a wealth of genetics and genomics data available through an intuitive Web-based interface. The goals of the MaizeGDB project are 3-fold: to provide a central repository for public maize information; to present the data through the MaizeGDB Web site in a way that recapitulates biological relationships; and to provide an array of computational tools that address biological questions in an easy-to-use manner at the site. In addition to these primary tasks, MaizeGDB team members also serve the community of maize geneticists by lending technical support for community activities, including the annual Maize Genetics Conference and various workshops, teaching researchers to use both the MaizeGDB Web site and Community Curation Tools, and engaging in collaboration with individual research groups to make their unique data types available through MaizeGDB. PMID:15888678

  17. Whole-Genome Mapping Reveals Novel QTL Clusters Associated with Main Agronomic Traits of Cabbage (Brassica oleracea var. capitata L.)

    PubMed Central

    Lv, Honghao; Wang, Qingbiao; Liu, Xing; Han, Fengqing; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Liu, Yumei; Li, Zhansheng; Zhang, Yangyong

    2016-01-01

    We describe a comprehensive quantitative trait locus (QTL) analysis for 24 main agronomic traits of cabbage. Field experiments were performed using a 196-line double haploid population in three seasons in 2011 and 2012 to evaluate important agronomic traits related to plant type, leaf, and head traits. In total, 144 QTLs with LOD threshold >3.0 were detected for the 24 agronomic traits: 25 for four plant-type-related traits, 64 for 10 leaf-related traits, and 55 for 10 head-related traits; each QTL explained 6.0–55.7% of phenotype variation. Of the QTLs, 95 had contribution rates higher than 10%, and 51 could be detected in more than one season. Major QTLs included Ph 3.1 (max R2 = 55.7, max LOD = 28.2) for plant height, Ll 3.2 (max R2 = 31.7, max LOD = 13.95) for leaf length, and Htd 3.2 (max R2 = 28.5, max LOD = 9.49) for head transverse diameter; these could all be detected in more than one season. Twelve QTL clusters were detected on eight chromosomes, and the most significant four included Indel481–scaffold18376 (3.20 Mb), with five QTLs for five traits; Indel64–scaffold35418 (2.22 Mb), six QTLs for six traits; scaffold39782–Indel84 (1.78 Mb), 11 QTLs for 11 traits; and Indel353–Indel245 (9.89 Mb), seven QTLs for six traits. Besides, most traits clustered within the same region were significantly correlated with each other. The candidate genes at these regions were also discussed. Robust QTLs and their clusters obtained in this study should prove useful for marker-assisted selection (MAS) in cabbage breeding and in furthering our understanding of the genetic control of these traits. PMID:27458471

  18. Whole-Genome Mapping Reveals Novel QTL Clusters Associated with Main Agronomic Traits of Cabbage (Brassica oleracea var. capitata L.).

    PubMed

    Lv, Honghao; Wang, Qingbiao; Liu, Xing; Han, Fengqing; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Liu, Yumei; Li, Zhansheng; Zhang, Yangyong

    2016-01-01

    We describe a comprehensive quantitative trait locus (QTL) analysis for 24 main agronomic traits of cabbage. Field experiments were performed using a 196-line double haploid population in three seasons in 2011 and 2012 to evaluate important agronomic traits related to plant type, leaf, and head traits. In total, 144 QTLs with LOD threshold >3.0 were detected for the 24 agronomic traits: 25 for four plant-type-related traits, 64 for 10 leaf-related traits, and 55 for 10 head-related traits; each QTL explained 6.0-55.7% of phenotype variation. Of the QTLs, 95 had contribution rates higher than 10%, and 51 could be detected in more than one season. Major QTLs included Ph 3.1 (max R (2) = 55.7, max LOD = 28.2) for plant height, Ll 3.2 (max R (2) = 31.7, max LOD = 13.95) for leaf length, and Htd 3.2 (max R (2) = 28.5, max LOD = 9.49) for head transverse diameter; these could all be detected in more than one season. Twelve QTL clusters were detected on eight chromosomes, and the most significant four included Indel481-scaffold18376 (3.20 Mb), with five QTLs for five traits; Indel64-scaffold35418 (2.22 Mb), six QTLs for six traits; scaffold39782-Indel84 (1.78 Mb), 11 QTLs for 11 traits; and Indel353-Indel245 (9.89 Mb), seven QTLs for six traits. Besides, most traits clustered within the same region were significantly correlated with each other. The candidate genes at these regions were also discussed. Robust QTLs and their clusters obtained in this study should prove useful for marker-assisted selection (MAS) in cabbage breeding and in furthering our understanding of the genetic control of these traits.

  19. Whole-Genome Mapping Reveals Novel QTL Clusters Associated with Main Agronomic Traits of Cabbage (Brassica oleracea var. capitata L.).

    PubMed

    Lv, Honghao; Wang, Qingbiao; Liu, Xing; Han, Fengqing; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Liu, Yumei; Li, Zhansheng; Zhang, Yangyong

    2016-01-01

    We describe a comprehensive quantitative trait locus (QTL) analysis for 24 main agronomic traits of cabbage. Field experiments were performed using a 196-line double haploid population in three seasons in 2011 and 2012 to evaluate important agronomic traits related to plant type, leaf, and head traits. In total, 144 QTLs with LOD threshold >3.0 were detected for the 24 agronomic traits: 25 for four plant-type-related traits, 64 for 10 leaf-related traits, and 55 for 10 head-related traits; each QTL explained 6.0-55.7% of phenotype variation. Of the QTLs, 95 had contribution rates higher than 10%, and 51 could be detected in more than one season. Major QTLs included Ph 3.1 (max R (2) = 55.7, max LOD = 28.2) for plant height, Ll 3.2 (max R (2) = 31.7, max LOD = 13.95) for leaf length, and Htd 3.2 (max R (2) = 28.5, max LOD = 9.49) for head transverse diameter; these could all be detected in more than one season. Twelve QTL clusters were detected on eight chromosomes, and the most significant four included Indel481-scaffold18376 (3.20 Mb), with five QTLs for five traits; Indel64-scaffold35418 (2.22 Mb), six QTLs for six traits; scaffold39782-Indel84 (1.78 Mb), 11 QTLs for 11 traits; and Indel353-Indel245 (9.89 Mb), seven QTLs for six traits. Besides, most traits clustered within the same region were significantly correlated with each other. The candidate genes at these regions were also discussed. Robust QTLs and their clusters obtained in this study should prove useful for marker-assisted selection (MAS) in cabbage breeding and in furthering our understanding of the genetic control of these traits. PMID:27458471

  20. Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

    PubMed Central

    Mathur, Chandni; Kathuria, Pooran C.; Dahiya, Pushpa; Singh, Anand B.

    2015-01-01

    Background Genetically modified, (GM) crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release. Objective To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize. Methods An integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE) and Immunoblot using food sensitized patients sera (n = 39) to non GM and GM maize antigens was performed. Results In silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05) variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF) revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF. Conclusion Cry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize. PMID:25706412

  1. Bacterial Diversity and Mycotoxin Reduction During Maize Fermentation (Steeping) for Ogi Production

    PubMed Central

    Okeke, Chiamaka A.; Ezekiel, Chibundu N.; Nwangburuka, Cyril C.; Sulyok, Michael; Ezeamagu, Cajethan O.; Adeleke, Rasheed A.; Dike, Stanley K.; Krska, Rudolf

    2015-01-01

    Bacterial diversity and community structure of two maize varieties (white and yellow) during fermentation/steeping for ogi production, and the influence of spontaneous fermentation on mycotoxin reduction in the gruel were studied. A total of 142 bacterial isolates obtained at 24–96 h intervals were preliminarily identified by conventional microbiological methods while 60 selected isolates were clustered into 39 OTUs consisting of 15 species, 10 genera, and 3 phyla by 16S rRNA sequence analysis. Lactic acid bacteria constituted about 63% of all isolated bacteria and the genus Pediococcus dominated (white maize = 84.8%; yellow maize = 74.4%). Pediococcus acidilactici and Lactobacillus paraplantarum were found at all steeping intervals of white and yellow maize, respectively, while P. claussenii was present only at the climax stage of steeping white maize. In both maize varieties, P. pentosaceus was found at 24–72 h. Mycotoxin concentrations (μg/kg) in the unsteeped grains were: white maize (aflatoxin B1 = 0.60; citrinin = 85.8; cyclopiazonic acid = 23.5; fumonisins (B1/B2/B3) = 68.4–483; zearalenone = 3.3) and yellow maize (aflatoxins (B1/B2/M1) = 22.7–513; citrinin = 16,800; cyclopiazonic acid = 247; fumonisins (B1/B2/B3) = 252–1,586; zearalenone = 205). Mycotoxins in both maize varieties were significantly (p < 0.05) reduced across steeping periods. This study reports for the first time: (a) the association of L. paraplantarum, P. acidilactici, and P. claussenii with ogi production from maize, (b) citrinin occurrence in Nigerian maize and ogi, and (c) aflatoxin M1, citrinin and cyclopiazonic acid degradation/loss due to fermentation in traditional cereal-based fermented food. PMID:26697001

  2. Possible effects of climate change on wheat and maize crops in France

    SciTech Connect

    Delecolle, R.; Ruget, F.; Ripoche, D.; Gosse, G.

    1995-12-31

    This study evaluates the possible effects of climate modifications induced by increasing trace gas concentrations in the atmosphere, on wheat (Triticum aestivum L.) and maize (Zea mays L.) yield and water demand in France. CERES-wheat and CERES-maize models are used with two French weather series and soil conditions. Weather variables were varied from present conditions, as simulated by various global climate models (GCMs). This chapter emphasizes the process of model calibration and the consequent uncertainties in final simulated results. Under the simulation conditions: (i) season lengths are shortened under climate change scenarios; (ii) yield decreases under climate change alone, but the decrease can be somewhat counteracted by direct CO{sub 2} effects on the crop, up to a 5 C temperature increase; and (iii) water use decreases under climate changes. Even if the large diversity of French climates and soils prohibits generalization of these results to the entire country, the main conclusions are: (i) under both temperate and Mediterranean climates, winter cereal yields will not be decreased by future conditions, provided that irrigation supply is not limiting under dry conditions and (ii) under temperate climate, maize could take advantage of development phase shrinkage and improve its radiation use efficiency. Changing sowing date produces varying results according to weather scenario, plant, and location. A more precise knowledge of initial soil water or temperature under changing conditions is necessary before optimal agronomic adaptation to future climate can be suggested.

  3. Effects of maize cultivation on nitrogen and phosphorus loadings to drainage channels in Central Chile.

    PubMed

    Corradini, Fabio; Nájera, Francisco; Casanova, Manuel; Tapia, Yasna; Singh, Ranvir; do Salazar, Osval

    2015-11-01

    There are concerns about the impact of maize cultivation with high applications of nitrogen (N) and phosphorus (P) on water quality in surface waters in Mediterranean Central Chile. This study estimated the contribution of N and P from maize fields to nearby drainage channels and evaluated the effects in water quality. An N and P budget was drawn up for three fields managed with a maize-fallow system, El Maitén (20.7 ha), El Naranjal (14.9 ha) and El Caleuche (4.2 ha), and water quality variables (pH, EC, dissolved oxygen, total solids, turbidity, NO3-N, NH4-N, PO4(3-), COD, total N, total P and sulphate) were monitored in nearby drainage channels. The N and P balances for the three fields indicated a high risk of N and P non-point source pollution, with fertiliser management, soil texture and climate factors determining the temporal variations in water quality parameters. Elevated levels of NH4-N and PO4(3-) in the drainage channels were usually observed during the winter period, while NO3- concentrations did not show a clear tendency. The results suggest that excessive slurry application during winter represents a very high risk of N and P runoff to drainage channels. Overall, great emphasis must be placed on good agronomic management of fields neighbouring drainage channels, including accurately calculating N and P fertiliser rates and establishing mitigation measures.

  4. Effects of maize cultivation on nitrogen and phosphorus loadings to drainage channels in Central Chile.

    PubMed

    Corradini, Fabio; Nájera, Francisco; Casanova, Manuel; Tapia, Yasna; Singh, Ranvir; do Salazar, Osval

    2015-11-01

    There are concerns about the impact of maize cultivation with high applications of nitrogen (N) and phosphorus (P) on water quality in surface waters in Mediterranean Central Chile. This study estimated the contribution of N and P from maize fields to nearby drainage channels and evaluated the effects in water quality. An N and P budget was drawn up for three fields managed with a maize-fallow system, El Maitén (20.7 ha), El Naranjal (14.9 ha) and El Caleuche (4.2 ha), and water quality variables (pH, EC, dissolved oxygen, total solids, turbidity, NO3-N, NH4-N, PO4(3-), COD, total N, total P and sulphate) were monitored in nearby drainage channels. The N and P balances for the three fields indicated a high risk of N and P non-point source pollution, with fertiliser management, soil texture and climate factors determining the temporal variations in water quality parameters. Elevated levels of NH4-N and PO4(3-) in the drainage channels were usually observed during the winter period, while NO3- concentrations did not show a clear tendency. The results suggest that excessive slurry application during winter represents a very high risk of N and P runoff to drainage channels. Overall, great emphasis must be placed on good agronomic management of fields neighbouring drainage channels, including accurately calculating N and P fertiliser rates and establishing mitigation measures. PMID:26490735

  5. Fungi producing significant mycotoxins.

    PubMed

    2012-01-01

    Mycotoxins are secondary metabolites of microfungi that are known to cause sickness or death in humans or animals. Although many such toxic metabolites are known, it is generally agreed that only a few are significant in causing disease: aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone, and ergot alkaloids. These toxins are produced by just a few species from the common genera Aspergillus, Penicillium, Fusarium, and Claviceps. All Aspergillus and Penicillium species either are commensals, growing in crops without obvious signs of pathogenicity, or invade crops after harvest and produce toxins during drying and storage. In contrast, the important Fusarium and Claviceps species infect crops before harvest. The most important Aspergillus species, occurring in warmer climates, are A. flavus and A. parasiticus, which produce aflatoxins in maize, groundnuts, tree nuts, and, less frequently, other commodities. The main ochratoxin A producers, A. ochraceus and A. carbonarius, commonly occur in grapes, dried vine fruits, wine, and coffee. Penicillium verrucosum also produces ochratoxin A but occurs only in cool temperate climates, where it infects small grains. F. verticillioides is ubiquitous in maize, with an endophytic nature, and produces fumonisins, which are generally more prevalent when crops are under drought stress or suffer excessive insect damage. It has recently been shown that Aspergillus niger also produces fumonisins, and several commodities may be affected. F. graminearum, which is the major producer of deoxynivalenol and zearalenone, is pathogenic on maize, wheat, and barley and produces these toxins whenever it infects these grains before harvest. Also included is a short section on Claviceps purpurea, which produces sclerotia among the seeds in grasses, including wheat, barley, and triticale. The main thrust of the chapter contains information on the identification of these fungi and their morphological characteristics, as well as factors

  6. Accumulation potentials of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays).

    PubMed

    Krippner, Johanna; Falk, Sandy; Brunn, Hubertus; Georgii, Sebastian; Schubert, Sven; Stahl, Thorsten

    2015-04-15

    Uptake of perfluoroalkyl acids (PFAAs) by maize represents a potential source of exposure for humans, either directly or indirectly via feed for animals raised for human consumption. The aim of the following study was, therefore, to determine the accumulation potential of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in maize (Zea mays). Two different concentrations of PFAAs were applied as aqueous solution to the soil to attain target concentrations of 0.25 mg or 1.00 mg of PFAA per kg of soil. Maize was grown in pots, and after harvesting, PFAA concentrations were measured in the straw and kernels of maize. PFCA and PFSA concentrations of straw decreased significantly with increasing chain length. In maize kernels, only PFCAs with a chain length ≤ C8 as well as perfluorobutanesulfonic acid (PFBS) were detected. The highest soil-to-plant transfer for both straw and kernels was determined for short-chained PFCAs and PFSAs.

  7. Preceramic maize from Paredones and Huaca Prieta, Peru.

    PubMed

    Grobman, Alexander; Bonavia, Duccio; Dillehay, Tom D; Piperno, Dolores R; Iriarte, José; Holst, Irene

    2012-01-31

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, important problems remain. Among them is the paucity of information on maize's early morphological evolution and racial diversification brought about in part by the poor preservation of macrofossils dating to the pre-5000 calibrated years before the present period from obligate dispersal routes located in the tropical forest. We report newly discovered macrobotanical and microbotanical remains of maize that shed significant light on the chronology, land race evolution, and cultural contexts associated with the crop's early movements into South America and adaptation to new environments. The evidence comes from the coastal Peruvian sites of Paredones and Huaca Prieta, Peru; dates from the middle and late preceramic and early ceramic periods (between ca. 6700 and 3000 calibrated years before the present); and constitutes some of the earliest known cobs, husks, stalks, and tassels. The macrobotanical record indicates that a diversity of racial complexes characteristic of the Andean region emerged during the preceramic era. In addition, accelerator mass spectrometry radiocarbon determinations carried out directly on different structures of preserved maize plants strongly suggest that assays on burned cobs are more reliable than those on unburned cobs. Our findings contribute to knowledge of the early diffusion of maize and agriculture and have broader implications for understanding the development of early preindustrial human societies.

  8. Preceramic maize from Paredones and Huaca Prieta, Peru

    PubMed Central

    Grobman, Alexander; Bonavia, Duccio; Dillehay, Tom D.; Piperno, Dolores R.; Iriarte, José; Holst, Irene

    2012-01-01

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, important problems remain. Among them is the paucity of information on maize's early morphological evolution and racial diversification brought about in part by the poor preservation of macrofossils dating to the pre-5000 calibrated years before the present period from obligate dispersal routes located in the tropical forest. We report newly discovered macrobotanical and microbotanical remains of maize that shed significant light on the chronology, land race evolution, and cultural contexts associated with the crop's early movements into South America and adaptation to new environments. The evidence comes from the coastal Peruvian sites of Paredones and Huaca Prieta, Peru; dates from the middle and late preceramic and early ceramic periods (between ca. 6700 and 3000 calibrated years before the present); and constitutes some of the earliest known cobs, husks, stalks, and tassels. The macrobotanical record indicates that a diversity of racial complexes characteristic of the Andean region emerged during the preceramic era. In addition, accelerator mass spectrometry radiocarbon determinations carried out directly on different structures of preserved maize plants strongly suggest that assays on burned cobs are more reliable than those on unburned cobs. Our findings contribute to knowledge of the early diffusion of maize and agriculture and have broader implications for understanding the development of early preindustrial human societies. PMID:22307642

  9. Linkages Among Agronomic, Environmental and Weed Management Characteristics in North American Sweet Corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Performance of weed management systems varies greatly across the landscape in both growers’ fields and in experimental trials conducted by agricultural scientists. Using agronomic, environmental, and weed management information from growers’ fields and experimental trials, we identified dominant ch...

  10. Modern maize hybrids in Northeast China exhibit increased yield potential and resource use efficiency despite adverse climate change.

    PubMed

    Chen, Xiaochao; Chen, Fanjun; Chen, Yanling; Gao, Qiang; Yang, Xiaoli; Yuan, Lixing; Zhang, Fusuo; Mi, Guohua

    2013-03-01

    The impact of global changes on food security is of serious concern. Breeding novel crop cultivars adaptable to climate change is one potential solution, but this approach requires an understanding of complex adaptive traits for climate-change conditions. In this study, plant growth, nitrogen (N) uptake, and yield in relation to climatic resource use efficiency of nine representative maize cultivars released between 1973 and 2000 in China were investigated in a 2-year field experiment under three N applications. The Hybrid-Maize model was used to simulate maize yield potential in the period from 1973 to 2011. During the past four decades, the total thermal time (growing degree days) increased whereas the total precipitation and sunshine hours decreased. This climate change led to a reduction of maize potential yield by an average of 12.9% across different hybrids. However, the potential yield of individual hybrids increased by 118.5 kg ha(-1)  yr(-1) with increasing year of release. From 1973 to 2000, the use efficiency of sunshine hours, thermal time, and precipitation resources increased by 37%, 40%, and 41%, respectively. The late developed hybrids showed less reduction in yield potential in current climate conditions than old cultivars, indicating some adaptation to new conditions. Since the mid-1990s, however, the yield impact of climate change exhibited little change, and even a slight worsening for new cultivars. Modern breeding increased ear fertility and grain-filling rate, and delayed leaf senescence without modification in net photosynthetic rate. The trade-off associated with delayed leaf senescence was decreased grain N concentration rather than increased plant N uptake, therefore N agronomic efficiency increased simultaneously. It is concluded that modern maize hybrids tolerate the climatic changes mainly by constitutively optimizing plant productivity. Maize breeding programs in the future should pay more attention to cope with the limiting

  11. Agronomic and environmental implications of enhanced s-triazine degradation

    USGS Publications Warehouse

    Krutz, L. J.; Dale L. Shaner,; Mark A. Weaver,; Webb, Richard M.; Zablotowicz, Robert M.; Reddy, Krishna N.; Huang, Y.; Thompson, S. J.

    2010-01-01

    Novel catabolic pathways enabling rapid detoxification of s-triazine herbicides have been elucidated and detected at a growing number of locations. The genes responsible for s-triazine mineralization, i.e. atzABCDEF and trzNDF, occur in at least four bacterial phyla and are implicated in the development of enhanced degradation in agricultural soils from all continents except Antarctica. Enhanced degradation occurs in at least nine crops and six crop rotation systems that rely on s-triazine herbicides for weed control, and, with the exception of acidic soil conditions and s-triazine application frequency, adaptation of the microbial population is independent of soil physiochemical properties and cultural management practices. From an agronomic perspective, residual weed control could be reduced tenfold in s-triazine-adapted relative to non-adapted soils. From an environmental standpoint, the off-site loss of total s-triazine residues could be overestimated 13-fold in adapted soils if altered persistence estimates and metabolic pathways are not reflected in fate and transport models. Empirical models requiring soil pH and s-triazine use history as input parameters predict atrazine persistence more accurately than historical estimates, thereby allowing practitioners to adjust weed control strategies and model input values when warranted. 

  12. Organic complexed superphosphates (CSP): physicochemical characterization and agronomical properties.

    PubMed

    Erro, Javier; Urrutia, Oscar; Baigorri, Roberto; Aparicio-Tejo, Pedro; Irigoyen, Ignacio; Storino, Francesco; Torino, Francesco; Mandado, Marcos; Yvin, Jean Claude; Garcia-Mina, Jose M

    2012-02-29

    A new type of superphosphate (organic complexed superphosphate (CSP)) has been developed by the introduction of organic chelating agents, preferably a humic acid (HA), into the chemical reaction of single superphosphate (SSP) production. This modification yielded a product containing monocalcium phosphate complexed by the chelating organic agent through Ca bridges. Theoretically, the presence of these monocalcium-phosphate-humic complexes (MPHC) inhibits phosphate fixation in soil, thus increasing P fertilizer efficiency. This study investigateed the structural and functional features of CSP fertilizers produced employing diverse HA with different structural features. To this end were used complementary analytical techniques: solid-phase ³¹P NMR, ¹³C NMR, laser-confocal microscopy, X-ray diffraction, and molecular modeling. Finally, the agronomical efficiency of four CSP have been compared with that of SSP as P sources for wheat plants grown in both alkaline and acidic soils in greenhouse pot trials under controlled conditions. The results obtained from the diverse analytical studies showed the formation of MPHC in CSP. Plant-soil studies showed that CSP products were more efficient than SSP in providing available phosphate for wheat plants cultivated in various soils with different physicochemical features. This fact is probably associated with the ability of CSP complexes to inhibit phosphate fixation in soil. PMID:22300509

  13. Has selection for improved agronomic traits made reed canarygrass invasive?

    PubMed

    Jakubowski, Andrew R; Casler, Michael D; Jackson, Randall D

    2011-01-01

    Plant breeders have played an essential role in improving agricultural crops, and their efforts will be critical to meet the increasing demand for cellulosic bioenergy feedstocks. However, a major concern is the potential development of novel invasive species that result from breeders' efforts to improve agronomic traits in a crop. We use reed canarygrass as a case study to evaluate the potential of plant breeding to give rise to invasive species. Reed canarygrass has been improved by breeders for use as a forage crop, but it is unclear whether breeding efforts have given rise to more vigorous populations of the species. We evaluated cultivars, European wild, and North American invader populations in upland and wetland environments to identify differences in vigor between the groups of populations. While cultivars were among the most vigorous populations in an agricultural environment (upland soils with nitrogen addition), there were no differences in above- or below-ground production between any populations in wetland environments. These results suggest that breeding has only marginally increased vigor in upland environments and that these gains are not maintained in wetland environments. Breeding focuses on selection for improvements of a specific target population of environments, and stability across a wide range of environments has proved elusive for even the most intensively bred crops. We conclude that breeding efforts are not responsible for wetland invasion by reed canarygrass and offer guidelines that will help reduce the possibility of breeding programs releasing cultivars that will become invasive. PMID:21991347

  14. Agronomical Parameters, Sugar Profile and Antioxidant Compounds of “Catherine” Peach Cultivar Influenced by Different Plum Rootstocks

    PubMed Central

    Font i Forcada, Carolina; Gogorcena, Yolanda; Moreno, María Ángeles

    2014-01-01

    The influence of seven plum rootstocks (Adesoto, Monpol, Montizo, Puebla de Soto 67 AD, PM 105 AD, St. Julien GF 655/2 and Constantí 1) on individual and total sugars, as well as on antioxidant content in fruit flesh of “Catherine” peaches, was evaluated for three years. Agronomical and basic fruit quality parameters were also determined. At twelve years after budding, significant differences were found between rootstocks for the different agronomic and fruit quality traits evaluated. The Pollizo plum rootstocks Adesoto and PM 105 AD seem to induce higher sweetness to peach fruits, based on soluble solids content, individual (sucrose, fructose and sorbitol) and total sugars. A clear tendency was also observed with the rootstock Adesoto, inducing the highest content of phenolics, flavonoids, vitamin C and relative antioxidant capacity (RAC). Thus, the results of this study demonstrate the significant effect of rootstock on the sugar profile and phytochemical characteristics of peach fruits. In addition, this work shows the importance of the sugar profile, because specific sugars play an important role in peach flavour quality, as well as the studied phytochemical compounds when looking for high quality peaches with enhanced health properties. PMID:24496242

  15. Inbreeding drives maize centromere evolution

    PubMed Central

    Schneider, Kevin L.; Xie, Zidian; Wolfgruber, Thomas K.; Presting, Gernot G.

    2016-01-01

    Functional centromeres, the chromosomal sites of spindle attachment during cell division, are marked epigenetically by the centromere-specific histone H3 variant cenH3 and typically contain long stretches of centromere-specific tandem DNA repeats (∼1.8 Mb in maize). In 23 inbreds of domesticated maize chosen to represent the genetic diversity of maize germplasm, partial or nearly complete loss of the tandem DNA repeat CentC precedes 57 independent cenH3 relocation events that result in neocentromere formation. Chromosomal regions with newly acquired cenH3 are colonized by the centromere-specific retrotransposon CR2 at a rate that would result in centromere-sized CR2 clusters in 20,000–95,000 y. Three lines of evidence indicate that CentC loss is linked to inbreeding, including (i) CEN10 of temperate lineages, presumed to have experienced a genetic bottleneck, contain less CentC than their tropical relatives; (ii) strong selection for centromere-linked genes in domesticated maize reduced diversity at seven of the ten maize centromeres to only one or two postdomestication haplotypes; and (iii) the centromere with the largest number of haplotypes in domesticated maize (CEN7) has the highest CentC levels in nearly all domesticated lines. Rare recombinations introduced one (CEN2) or more (CEN5) alternate CEN haplotypes while retaining a single haplotype at domestication loci linked to these centromeres. Taken together, this evidence strongly suggests that inbreeding, favored by postdomestication selection for centromere-linked genes affecting key domestication or agricultural traits, drives replacement of the tandem centromere repeats in maize and other crop plants. Similar forces may act during speciation in natural systems. PMID:26858403

  16. Inbreeding drives maize centromere evolution.

    PubMed

    Schneider, Kevin L; Xie, Zidian; Wolfgruber, Thomas K; Presting, Gernot G

    2016-02-23

    Functional centromeres, the chromosomal sites of spindle attachment during cell division, are marked epigenetically by the centromere-specific histone H3 variant cenH3 and typically contain long stretches of centromere-specific tandem DNA repeats (∼1.8 Mb in maize). In 23 inbreds of domesticated maize chosen to represent the genetic diversity of maize germplasm, partial or nearly complete loss of the tandem DNA repeat CentC precedes 57 independent cenH3 relocation events that result in neocentromere formation. Chromosomal regions with newly acquired cenH3 are colonized by the centromere-specific retrotransposon CR2 at a rate that would result in centromere-sized CR2 clusters in 20,000-95,000 y. Three lines of evidence indicate that CentC loss is linked to inbreeding, including (i) CEN10 of temperate lineages, presumed to have experienced a genetic bottleneck, contain less CentC than their tropical relatives; (ii) strong selection for centromere-linked genes in domesticated maize reduced diversity at seven of the ten maize centromeres to only one or two postdomestication haplotypes; and (iii) the centromere with the largest number of haplotypes in domesticated maize (CEN7) has the highest CentC levels in nearly all domesticated lines. Rare recombinations introduced one (CEN2) or more (CEN5) alternate CEN haplotypes while retaining a single haplotype at domestication loci linked to these centromeres. Taken together, this evidence strongly suggests that inbreeding, favored by postdomestication selection for centromere-linked genes affecting key domestication or agricultural traits, drives replacement of the tandem centromere repeats in maize and other crop plants. Similar forces may act during speciation in natural systems. PMID:26858403

  17. pH-dependent mineral release and surface properties of cornstraw biochar: agronomic implications.

    PubMed

    Silber, A; Levkovitch, I; Graber, E R

    2010-12-15

    Surface charge and pH-dependent nutrient release properties of cornstraw biochar were examined to elucidate its potential agronomic benefits. Kinetics of element release was characterized by rapid H(+) consumption and rapid, pH-dependent P, Ca, and Mg release, followed by zero-order H(+) consumption and mineral dissolution reactions. Initial K release was not pH-dependent, nor was it followed by a zero-order reaction at any pH. Rapid and constant rate P releases were significant, having the potential to substitute substantial proportions of P fertilizer. K releases were also significant and may replace conventional K fertilizers, however, not long-term plant demand. The cation exchange capacity (CEC) of the biochar leached with a mild acidic solution increased linearly from 179 to 888 mmol(c) (kg C)(-1) over a pH range of 4-8, while the anion exchange capacity of 154 mmol(c) (kg C)(-1) was constant over the same pH range. Since native soil organic constituents have much higher CEC values (average 2800 mmol(c) (kg C)(-1) at pH 7), improved soil fertility as a result of enhanced cation retention by the biochar probably will be favorable only in sandy and low organic matter soils, unless surface oxidation during aging significantly increases its CEC. PMID:21090742

  18. MaizeGDB's New Genome Browser Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. Based upon the 2006 MaizeGDB Working Group Report (available at http://www.maizegdb.org/working_group.php) and the Allerton Report (http://www.maizegdb.org/AllertonReport.doc), it has become evident that th...

  19. The MaizeGDB Genome Browser

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB (http://www.maizegdb.org) is the community database for maize genetics and genomics. As part of a larger effort to develop MaizeGDB into a more sequence-centric resource, we recently implemented a genome browser. The GBrowse platform was chosen for this endeavor based on results of a survey...

  20. MaizeGDB: New tools and resource

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB, the USDA-ARS genetics and genomics database, is a highly curated, community-oriented informatics service to researchers focused on the crop plant and model organism Zea mays. MaizeGDB facilitates maize research by curating, integrating, and maintaining a database that serves as the central...

  1. The Genetic Architecture of Maize Flowering Time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flowering time is the key trait controlling adaptation of plants to their local environment, and, in an outcrossing species like maize, it is a complex trait. Variation for this complex trait was dissected in maize using a novel set of 5000 recombinant inbred lines (maize Nested Association Mapping...

  2. Field-Evolved Resistance to Bt Maize by Western Corn Rootworm

    PubMed Central

    Gassmann, Aaron J.; Petzold-Maxwell, Jennifer L.; Keweshan, Ryan S.; Dunbar, Mike W.

    2011-01-01

    Background Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are planted on millions of hectares annually, reducing the use of conventional insecticides and suppressing pests. However, the evolution of resistance could cut short these benefits. A primary pest targeted by Bt maize in the United States is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae). Methodology/Principal Findings We report that fields identified by farmers as having severe rootworm feeding injury to Bt maize contained populations of western corn rootworm that displayed significantly higher survival on Cry3Bb1 maize in laboratory bioassays than did western corn rootworm from fields not associated with such feeding injury. In all cases, fields experiencing severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers indicated that Cry3Bb1 maize had been grown in those fields for at least three consecutive years. There was a significant positive correlation between the number of years Cry3Bb1 maize had been grown in a field and the survival of rootworm populations on Cry3Bb1 maize in bioassays. However, there was no significant correlation among populations for survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of cross resistance between these Bt toxins. Conclusions/Significance This is the first report of field-evolved resistance to a Bt toxin by the western corn rootworm and by any species of Coleoptera. Insufficient planting of refuges and non-recessive inheritance of resistance may have contributed to resistance. These results suggest that improvements in resistance management and a more integrated approach to the use of Bt crops may be necessary. PMID:21829470

  3. Maize, tropical (Zea mays L.).

    PubMed

    Assem, Shireen K

    2015-01-01

    Maize (Zea mays L.) is the third most important food crop globally after wheat and rice. In sub-Saharan Africa, tropical maize has traditionally been the main staple of the diet; 95 % of the maize grown is consumed directly as human food and as an important source of income for the resource-poor rural population. The biotechnological approach to engineer biotic and abiotic traits implies the availability of an efficient plant transformation method. The production of genetically transformed plants depends both on the ability to integrate foreign genes into target cells and the efficiency with which plants are regenerated. Maize transformation and regeneration through immature embryo culture is the most efficient system to regenerate normal transgenic plants. However, this system is highly genotype dependent. Genotypes adapted to tropic areas are difficult to regenerate. Therefore, transformation methods used with model genotypes adapted to temperate areas are not necessarily efficient with tropical lines. Agrobacterium-mediated transformation is the method of choice since it has been first achieved in 1996. In this report, we describe a transformation method used successfully with several tropical maize lines. All the steps of transformation and regeneration are described in details. This protocol can be used with a wide variety of tropical lines. However, some modifications may be needed with recalcitrant lines.

  4. Induced resistance responses in maize.

    PubMed

    Morris, S W; Vernooij, B; Titatarn, S; Starrett, M; Thomas, S; Wiltse, C C; Frederiksen, R A; Bhandhufalck, A; Hulbert, S; Uknes, S

    1998-07-01

    Systemic acquired resistance (SAR) is a widely distributed plant defense system that confers broad-spectrum disease resistance and is accompanied by coordinate expression of the so-called SAR genes. This type of resistance and SAR gene expression can be mimicked with chemical inducers of resistance. Here, we report that chemical inducers of resistance are active in maize. Chemical induction increases resistance to downy mildew and activates expression of the maize PR-1 and PR-5 genes. These genes are also coordinately activated by pathogen infection and function as indicators of the defense reaction. Specifically, after pathogen infection, the PR-1 and PR-5 genes are induced more rapidly and more strongly in an incompatible than in a compatible interaction. In addition, we show that monocot lesion mimic plants also express these defense-related genes and that they have increased levels of salicylic acid after lesions develop, similar to pathogeninfected maize plants. The existence of chemically inducible disease resistance and PR-1 and PR-5 gene expression in maize indicates that maize is similar to dicots in many aspects of induced resistance. This reinforces the notion of an ancient plant-inducible defense pathway against pathogen attack that is shared between monocots and dicots.

  5. Applied Mathematics for agronomical engineers in Spain at UPM

    NASA Astrophysics Data System (ADS)

    Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Fabregat, J.; Sanchez, M. E.

    2009-04-01

    Mathematics, created or discovered, are a global human conceptual endowment, containing large systems of knowledge, and varied skills to use definite parts of them, in creation or discovery, or for applications, e.g. in Physics, or notably in engineering behaviour. When getting upper intellectual levels in the 19th century, the agronomical science and praxis was noticeably or mainly organised in Spain in agronomical engineering schools and also in institutes, together with technician schools, also with different lower lever centres, and they have evolved with progress and they are much changing at present to a EEES schema (Bolonia process). They work in different lines that need some basis or skills from mathematics. The vocation to start such careers, that have varied curriculums, contains only some mathematics, and the number of credits for mathematics is restrained because time is necessary for other initial sciences such as applied chemistry, biology, ecology and soil sciences, but some basis and skill of maths are needed, also with Physics, at least for electricity, machines, construction, economics at initial ground levels, and also for Statistics that are here considered part of Applied Mathematics. The ways of teaching mathematical basis and skills are especial, and are different from the practical ways needed e. g. for Soil Sciences, and they involve especial efforts from students, and especial controls or exams that guide much learning. The mathematics have a very large accepted content that uses mostly a standard logic, and that is remarkably stable and international, rather similar notation and expressions being used with different main languages. For engineering the logical basis is really often not taught, but the use of it is transferred, especially for calculus that requires both adapted somehow simplified schemas and the learning of a specific skill to use it, and also for linear algebra. The basic forms of differential calculus in several

  6. Characterization of agronomic and quality traits and HSW-G5 compositions from the progenies of common wheat (Triticum aestivum L.) with different protein content.

    PubMed

    Bian, M; Sun, D K; Sun, D F; Sun, G L

    2015-01-01

    High molecular weight glutenin subunits (HMW-GS) play an essential role in wheat processing quality. In this study, we evaluated the genetic pattern with HMW-GS composition between generations and examined whether agronomic and quality traits were correlated with each other. A wheat (Triticum aestivum L.) cultivar with high protein content and 2 cultivars with low protein content were subjected to a reciprocal cross. Sixteen agronomic and 4 quality characteristics were investigated. A total of 216 seeds from each F2 generation were chosen randomly and analyzed for HMW-GS composition using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Agronomic and quality characteristics were not significantly different between reciprocal crosses, indicating no cytoplasmic effect on the characteristics studied. The separation ratio of 2 HMW-GS loci was 9:3:3:1, indicating no linkage between any 2 loci. The novel HMW-GS N was detected in cultivar R145, which did not follow the Mendelian segregation ratio. A Glu-A1a(1) band was not detected in 1 individual from Tian8901xR145. Average grain weight per spike was significantly correlated with quality characteristics and may be a suitable criterion for selecting high protein content in wheat breeding programs. PMID:25867343

  7. Zmspds2 maize gene

    PubMed Central

    Rodríguez-Kessler, Margarita

    2008-01-01

    During the last decade, growing evidence has arisen referring the importance of the proper regulation of plant polyamine metabolism in the response to stress conditions. Being the activation of signaling pathways, the stabilization of anionic molecules and prevention of their degradation, as well as the free radical scavenger properties of polyamines some possible mechanisms exerted by these amines. Accumulation of polyamines (putrescine, spermidine and spermine) has been associated to plant tolerance to a wide array of environmental stresses. The synthesis of spermidine and spermine is mediated by aminopropyltransferases (spermidine and spermine synthases) which constitute a class of widely distributed enzymes that use decarboxylated S-adenosylmethionine as an aminopropyl donor, and putrescine or spermidine as an amino acceptor. We recently reported the effect of salt stress on the expression of aminopropyltransferase genes in maize seedlings. Our data revealed a time and NaCl dependent regulation of the Zmspds2 and Zmspds1 genes, possibly mediated by abscisic acid, since these genes were regulated at the transcriptional level by this plant hormone. In this addendum, we show that the Zmspds2 gene initially classified as spermidine synthase might encode a spermine synthase based on an in silico analysis. This is discussed in terms of protein homologies and specific amino acid substitutions between aminopropyltransferase enzymes. PMID:19704464

  8. Modeling kinetics of aflatoxin production by Aspergillus flavus in maize-based medium and maize grain.

    PubMed

    Garcia, Daiana; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2013-03-15

    Predictive mycology has dealt mainly with germination, growth and inactivation of fungi while the issue of mycotoxin production remains relatively unexplored. Very few studies provide biomass dry weight/colony size data along with mycotoxin data for the same sample times, thus the ratio mycotoxin accumulation per fungal biomass dry weight/colony size has rarely been reported. For this reason, the objective of the present study was to model the kinetics of mycotoxin production under the assumption of existing both no-growth-associated and growth-associated production. Aspergillus flavus was chosen as a model mycotoxigenic microorganism, and it was grown in maize agar medium and maize grain at 0.90 and 0.99 aw at 25°C. A significant positive correlation (p<0.05) was observed among the biomass responses (colony radius and biomass dry weight) in agar medium and colony radius in maize at both aw levels assayed. The Luedeking-Piret model was used to model AFB1 production and reasonable percentages of variability were explained. Moreover, AFB1 production was in general slightly better predicted through colony area. As conclusion, aflatoxin production may follow a mixed-growth associated trend, confirming that toxin formation does not present a clear delay in relation to growth under certain conditions. PMID:23422844

  9. Classification of Maize and Weeds by Bayesian Networks

    NASA Astrophysics Data System (ADS)

    Chapron, Michel; Oprea, Alina; Sultana, Bogdan; Assemat, Louis

    2007-11-01

    Precision Agriculture is concerned with all sorts of within-field variability, spatially and temporally, that reduces the efficacy of agronomic practices applied in a uniform way all over the field. Because of these sources of heterogeneity, uniform management actions strongly reduce the efficiency of the resource input to the crop (i.e. fertilization, water) or for the agrochemicals use for pest control (i.e. herbicide). Moreover, this low efficacy means high environmental cost (pollution) and reduced economic return for the farmer. Weed plants are one of these sources of variability for the crop, as they occur in patches in the field. Detecting the location, size and internal density of these patches, along with identification of main weed species involved, open the way to a site-specific weed control strategy, where only patches of weeds would receive the appropriate herbicide (type and dose). Herein, an automatic recognition method of vegetal species is described. First, the pixels of soil and vegetation are classified in two classes, then the vegetation part of the input image is segmented from the distance image by using the watershed method and finally the leaves of the vegetation are partitioned in two parts maize and weeds thanks to the two Bayesian networks.

  10. Dynamics of maize carbon contribution to soil organic carbon in association with soil type and fertility level.

    PubMed

    Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

    2015-01-01

    Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition.

  11. Dynamics of Maize Carbon Contribution to Soil Organic Carbon in Association with Soil Type and Fertility Level

    PubMed Central

    Pei, Jiubo; Li, Hui; Li, Shuangyi; An, Tingting; Farmer, John; Fu, Shifeng; Wang, Jingkuan

    2015-01-01

    Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition. PMID:25774529

  12. Climatic models to predict occurrence of Fusarium toxins in wheat and maize.

    PubMed

    Schaafsma, A W; Hooker, D C

    2007-10-20

    Although forecasting Fusarium infections have useful implications, it may be argued that forecasting Fusarium toxins is more useful to help reduce their entry into the food chain. Several disease incidence models have been commercialized for wheat, but only one toxin prediction model from Ontario, Canada, "DONcast", has been validated extensively and commercialized to date for wheat, and another has been proposed for maize. In the development of these predictive tools, the variation in toxin levels associated with year and agronomic effects was estimated from simple linear models using wheat and maize samples taken from farm fields. In wheat, environment effects accounted for 48% of the variation in deoxynivalenol (DON) across all fields, followed by variety (27%), and previous crop (14 to 28%). In maize, hybrid accounted for 25% of the variation of either DON or fumonisin, followed by environment (12%), and when combined 42% of the variability was accounted for. The robust site-specific, DON forecast model accounted for up to 80% of the variation in DON, and has been used commercially for 5 years in Canada. Forecasting DON and fumonisins in maize is more difficult, because of its greater exposure to infection, the role of wounding in infection, the more important role of hybrid susceptibility, and the vast array of uncharacterized hybrids available in the marketplace. Nevertheless, using data collected from controlled experiments conducted in Argentina and the Philippines, a model was developed to predict fumonisin concentration using insect damage and weather variables, accounting for 82% of the variability of fumonisins. Using mycotoxins as a measure of disease outcome, as opposed to disease symptoms, offers a more robust prediction of mycotoxin risk, and it accounts for mycotoxin accumulation that occurs frequently in the absence of any change in Fusarium symptoms.

  13. High Susceptibility of Bt Maize to Aphids Enhances the Performance of Parasitoids of Lepidopteran Pests

    PubMed Central

    Faria, Cristina A.; Wäckers, Felix L.; Pritchard, Jeremy; Barrett, David A.; Turlings, Ted C.J.

    2007-01-01

    Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect. PMID:17622345

  14. Agronomic Characteristics Related to Grain Yield and Nutrient Use Efficiency for Wheat Production in China.

    PubMed

    Chuan, Limin; He, Ping; Zhao, Tongke; Zheng, Huaiguo; Xu, Xinpeng

    2016-01-01

    In order to make clear the recent status and trend of wheat (Triticum aestivum L.) production in China, datasets from multiple field experiments and published literature were collected to study the agronomic characteristics related to grain yield, fertilizer application and nutrient use efficiency from the year 2000 to 2011. The results showed that the mean grain yield of wheat in 2000-2011 was 5950 kg/ha, while the N, P2O5 and K2O application rates were 172, 102 and 91 kg/ha on average, respectively. The decrease in N and P2O5 and increase in K2O balanced the nutrient supply and was the main reason for yield increase. The partial factor productivity (PFP, kg grain yield produced per unit of N, P2O5 or K2O applied) values of N (PFP-N), P (PFP-P) and K (PFP-K) were in the ranges of 29.5~39.6, 43.4~74.9 and 44.1~76.5 kg/kg, respectively. While PFP-N showed no significant changes from 2000 to 2010, both PFP-P and PFP-K showed an increased trend over this period. The mean agronomic efficiency (AE, kg grain yield increased per unit of N, P2O5 or K2O applied) values of N (AEN), P (AEP) and K (AEK) were 9.4, 10.2 and 6.5 kg/kg, respectively. The AE values demonstrated marked inter-annual fluctuations, with the amplitude of fluctuation for AEN greater than those for AEP and AEK. The mean fertilizer recovery efficiency (RE, the fraction of nutrient uptake in aboveground plant dry matter to the nutrient of fertilizer application) values of N, P and K in the aboveground biomass were 33.1%, 24.3% and 28.4%, respectively. It was also revealed that different wheat ecological regions differ greatly in wheat productivity, fertilizer application and nutrient use efficiency. In summary, it was suggested that best nutrient management practices, i.e. fertilizer recommendation applied based on soil testing or yield response, with strategies to match the nutrient input with realistic yield and demand, or provided with the 4R's nutrient management (right time, right rate, right site and

  15. Agronomic Characteristics Related to Grain Yield and Nutrient Use Efficiency for Wheat Production in China

    PubMed Central

    Zheng, Huaiguo; Xu, Xinpeng

    2016-01-01

    In order to make clear the recent status and trend of wheat (Triticum aestivum L.) production in China, datasets from multiple field experiments and published literature were collected to study the agronomic characteristics related to grain yield, fertilizer application and nutrient use efficiency from the year 2000 to 2011. The results showed that the mean grain yield of wheat in 2000–2011 was 5950 kg/ha, while the N, P2O5 and K2O application rates were 172, 102 and 91 kg/ha on average, respectively. The decrease in N and P2O5 and increase in K2O balanced the nutrient supply and was the main reason for yield increase. The partial factor productivity (PFP, kg grain yield produced per unit of N, P2O5 or K2O applied) values of N (PFP-N), P (PFP-P) and K (PFP-K) were in the ranges of 29.5~39.6, 43.4~74.9 and 44.1~76.5 kg/kg, respectively. While PFP-N showed no significant changes from 2000 to 2010, both PFP-P and PFP-K showed an increased trend over this period. The mean agronomic efficiency (AE, kg grain yield increased per unit of N, P2O5 or K2O applied) values of N (AEN), P (AEP) and K (AEK) were 9.4, 10.2 and 6.5 kg/kg, respectively. The AE values demonstrated marked inter-annual fluctuations, with the amplitude of fluctuation for AEN greater than those for AEP and AEK. The mean fertilizer recovery efficiency (RE, the fraction of nutrient uptake in aboveground plant dry matter to the nutrient of fertilizer application) values of N, P and K in the aboveground biomass were 33.1%, 24.3% and 28.4%, respectively. It was also revealed that different wheat ecological regions differ greatly in wheat productivity, fertilizer application and nutrient use efficiency. In summary, it was suggested that best nutrient management practices, i.e. fertilizer recommendation applied based on soil testing or yield response, with strategies to match the nutrient input with realistic yield and demand, or provided with the 4R’s nutrient management (right time, right rate, right site

  16. MaizeGDB update: new tools, data and interface for the maize model organism database.

    PubMed

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org.

  17. MaizeGDB update: new tools, data and interface for the maize model organism database.

    PubMed

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  18. MaizeGDB update: new tools, data and interface for the maize model organism database

    PubMed Central

    Andorf, Carson M.; Cannon, Ethalinda K.; Portwood, John L.; Gardiner, Jack M.; Harper, Lisa C.; Schaeffer, Mary L.; Braun, Bremen L.; Campbell, Darwin A.; Vinnakota, Abhinav G.; Sribalusu, Venktanaga V.; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D.; Mauch, Emily D.; Rao, Bhavani S.; Birkett, Scott M.; Sen, Taner Z.; Lawrence-Dill, Carolyn J.

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  19. Use of benzimidazole agar plates to assess fall armyworm (Lepidoptera: Noctuidae) feeding on excised maize and sorghum leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an economically significant pest of sorghum and maize. To screen sorghum and maize germplasm for resistance to fall armyworm feeding, field, greenhouse, or lab bioassays are often utilized individually or in combinatio...

  20. The transcriptome landscape of early maize meiosis

    PubMed Central

    2014-01-01

    Background A major step in the higher plant life cycle is the decision to leave the mitotic cell cycle and begin the progression through the meiotic cell cycle that leads to the formation of gametes. The molecular mechanisms that regulate this transition and early meiosis remain largely unknown. To gain insight into gene expression features during the initiation of meiotic recombination, we profiled early prophase I meiocytes from maize (Zea mays) using capillary collection to isolate meiocytes, followed by RNA-seq. Results We detected ~2,000 genes as preferentially expressed during early meiotic prophase, most of them uncharacterized. Functional analysis uncovered the importance of several cellular processes in early meiosis. Processes significantly enriched in isolated meiocytes included proteolysis, protein targeting, chromatin modification and the regulation of redox homeostasis. The most significantly up-regulated processes in meiocytes were processes involved in carbohydrate metabolism. Consistent with this, many mitochondrial genes were up-regulated in meiocytes, including nuclear- and mitochondrial-encoded genes. The data were validated with real-time PCR and in situ hybridization and also used to generate a candidate maize homologue list of known meiotic genes from Arabidopsis. Conclusions Taken together, we present a high-resolution analysis of the transcriptome landscape in early meiosis of an important crop plant, providing support for choosing genes for detailed characterization of recombination initiation and regulation of early meiosis. Our data also reveal an important connection between meiotic processes and altered/increased energy production. PMID:24885405

  1. Tropical Legume Crop Rotation and Nitrogen Fertilizer Effects on Agronomic and Nitrogen Efficiency of Rice

    PubMed Central

    Rahman, Motior M.; Islam, Aminul M.; Azirun, Sofian M.; Boyce, Amru N.

    2014-01-01

    Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m−2 preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m−2. No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m−2 achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13–23% higher grain yield than rice after fallow rotation with 8 g N m−2. The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m−2 can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m−2. The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility. PMID:24971378

  2. Association of Agronomic Traits with SNP Markers in Durum Wheat (Triticum turgidum L. durum (Desf.))

    PubMed Central

    Hu, Xin; Ren, Jing; Ren, Xifeng; Huang, Sisi; Sabiel, Salih A. I.; Luo, Mingcheng; Nevo, Eviatar; Fu, Chunjie; Peng, Junhua; Sun, Dongfa

    2015-01-01

    Association mapping is a powerful approach to detect associations between traits of interest and genetic markers based on linkage disequilibrium (LD) in molecular plant breeding. In this study, 150 accessions of worldwide originated durum wheat germplasm (Triticum turgidum spp. durum) were genotyped using 1,366 SNP markers. The extent of LD on each chromosome was evaluated. Association of single nucleotide polymorphisms (SNP) markers with ten agronomic traits measured in four consecutive years was analyzed under a mix linear model (MLM). Two hundred and one significant association pairs were detected in the four years. Several markers were associated with one trait, and also some markers were associated with multiple traits. Some of the associated markers were in agreement with previous quantitative trait loci (QTL) analyses. The function and homology analyses of the corresponding ESTs of some SNP markers could explain many of the associations for plant height, length of main spike, number of spikelets on main spike, grain number per plant, and 1000-grain weight, etc. The SNP associations for the observed traits are generally clustered in specific chromosome regions of the wheat genome, mainly in 2A, 5A, 6A, 7A, 1B, and 6B chromosomes. This study demonstrates that association mapping can complement and enhance previous QTL analyses and provide additional information for marker-assisted selection. PMID:26110423

  3. Chemical stabilization of cadmium in acidic soil using alkaline agronomic and industrial by-products.

    PubMed

    Chang, Yao-Tsung; Hsi, Hsing-Cheng; Hseu, Zeng-Yei; Jheng, Shao-Liang

    2013-01-01

    In situ immobilization of heavy metals using reactive or stabilizing materials is a promising solution for soil remediation. Therefore, four agronomic and industrial by-products [wood biochar (WB), crushed oyster shell (OS), blast furnace slag (BFS), and fluidized-bed crystallized calcium (FBCC)] and CaCO3 were added to acidic soil (Cd = 8.71 mg kg(-1)) at the rates of 1%, 2%, and 4% and incubated for 90 d. Chinese cabbage (Brassica chinensis L.) was then planted in the soil to test the Cd uptake. The elevation in soil pH caused by adding the by-products produced a negative charge on the soil surface, which enhanced Cd adsorption. Consequently, the diethylenetriamine pentaacetic acid (DTPA)-extractable Cd content decreased significantly (P < 0.05) in the incubated soil. These results from the sequential extraction procedure indicated that Cd converted from the exchangeable fraction to the carbonate or Fe-Mn oxide fraction. The long-term effectiveness of Cd immobilization caused by applying the 4 by-products was much greater than that caused by applying CaCO3. Plant shoot biomass clearly increased because of the by-product soil amendment. Cd concentration in the shoots was < 10.0 mg kg(-1) following by-product application, as compared to 24 mg kg(-1) for plants growing in unamended soil. PMID:23947715

  4. Ferti-irrigational effect of paper mill effluent on agronomical characteristics of Abelmoschus esculentus L. (Okra).

    PubMed

    Kumar, Vinod; Chopra, A K

    2013-11-15

    The ferti-irrigational effect of an agro-based paper mill effluent on Abelmoschus esculentus (var. IHR-31) was investigated. Different doses of paper mill effluent viz. 5, 10, 25, 50, 75 and 100% were used for fertigation ofA. esculentus along with bore well water (control). The study revealed that paper mill effluent had significant (p < 0.05) effect on EC, pH, OC, Na+, K+, Ca2+, Mg2+, Fe2+, TKN, PO4(3-), SO4(2-), Cd, Cr, Cu, Mn and Zn of the soil in both seasons. Insignificant (p > 0.05) changes in WHC and bulk density of the soil were observed after irrigation with paper mill effluent. The agronomical performance of A. esculentus was increased from 5 to 25% and decreased from 50 to 100% concentration of paper mill effluent as compared to control in both seasons. The heavy metals concentration was increased in A. esculentus from 5 to 100% concentrations of paper mill effluent in both seasons. Biochemical components like crude proteins, crude fiber and crude carbohydrates were found maximum with 25% paper mill effluent in both seasons. The order of Contamination Factor (Cf) of various heavy metals was Cr > Cd > Mn > Zn > Cu for soil and Zn > Mn > Cu > Cr > Cd for A. esculentus plants after fertigation with paper mill effluent. Therefore, paper mill effluent can be used as a biofertigant after appropriate dilution to improve yield of A. esculentus.

  5. Ferti-irrigational effect of paper mill effluent on agronomical characteristics of Abelmoschus esculentus L. (Okra).

    PubMed

    Kumar, Vinod; Chopra, A K

    2013-11-15

    The ferti-irrigational effect of an agro-based paper mill effluent on Abelmoschus esculentus (var. IHR-31) was investigated. Different doses of paper mill effluent viz. 5, 10, 25, 50, 75 and 100% were used for fertigation ofA. esculentus along with bore well water (control). The study revealed that paper mill effluent had significant (p < 0.05) effect on EC, pH, OC, Na+, K+, Ca2+, Mg2+, Fe2+, TKN, PO4(3-), SO4(2-), Cd, Cr, Cu, Mn and Zn of the soil in both seasons. Insignificant (p > 0.05) changes in WHC and bulk density of the soil were observed after irrigation with paper mill effluent. The agronomical performance of A. esculentus was increased from 5 to 25% and decreased from 50 to 100% concentration of paper mill effluent as compared to control in both seasons. The heavy metals concentration was increased in A. esculentus from 5 to 100% concentrations of paper mill effluent in both seasons. Biochemical components like crude proteins, crude fiber and crude carbohydrates were found maximum with 25% paper mill effluent in both seasons. The order of Contamination Factor (Cf) of various heavy metals was Cr > Cd > Mn > Zn > Cu for soil and Zn > Mn > Cu > Cr > Cd for A. esculentus plants after fertigation with paper mill effluent. Therefore, paper mill effluent can be used as a biofertigant after appropriate dilution to improve yield of A. esculentus. PMID:24511684

  6. Agronomic effects of multi-year surface-banding of dairy slurry on grass.

    PubMed

    Bittman, S; Kowalenko, C G; Forge, T; Hunt, D E; Bounaix, F; Patni, N

    2007-12-01

    Sleigh-foot application of slurry manure is the best method for applying slurry manure on many forage fields. This study was designed to assess agronomic effectiveness of multi-year surface banding of dairy slurry on a sward of tall fescue (Festuca arundinacea Schreb.). Our study showed that with this application technology, crop recovery of total-N from applied manure in the long-term is only about 77% that of mineral fertilizer. Despite relative inefficiency of N uptake from manure, yield response to manure equaled that to fertilizer at equivalent total-N rates although N-recovery was significantly lower. About 26-32% of applied manure-N was stored in soil organic matter and the buildup of soil-N was related to application rate of organic N. At moderate applications rates (approx. 400 kg Nha(-1)a(-1)), soil N accumulated at about 120 kg ha(-1) annually compared to 98 kg ha(-1)a(-1) of unaccounted N, much of that probably volatilized and denitrified. Alternating between manure and fertilizer improved productivity per unit land area without increasing the rate of N non-recovery per unit of feed produced.

  7. Tropical legume crop rotation and nitrogen fertilizer effects on agronomic and nitrogen efficiency of rice.

    PubMed

    Rahman, Motior M; Islam, Aminul M; Azirun, Sofian M; Boyce, Amru N

    2014-01-01

    Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m(-2) preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m(-2). No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m(-2) achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13-23% higher grain yield than rice after fallow rotation with 8 g N m(-2). The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m(-2) can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m(-2). The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

  8. Sebacina vermifera: a unique root symbiont with vast agronomic potential.

    PubMed

    Ray, Prasun; Craven, Kelly D

    2016-01-01

    The Sebacinales belong to a taxonomically, ecologically, and physiologically diverse group of fungi in the Basidiomycota. While historically recognized as orchid mycorrhizae, recent DNA studies have brought to light both their pandemic distribution and the broad spectrum of mycorrhizal types they form. Indeed, ecological studies using molecular-based methods of detection have found Sebacinales fungi in field specimens of bryophytes (moss), pteridophytes (fern) and all families of herbaceous angiosperms (flowering plants) from temperate, subtropical and tropical regions. These natural host plants include, among others, liverworts, wheat, maize and Arabidopsis thaliana, the model plant traditionally viewed as non-mycorrhizal. The orchid mycorrhizal fungus Sebacina vermifera (MAFF 305830) was first isolated from the Australian orchid Cyrtostylis reniformis. Research performed with this strain clearly indicates its plant growth promoting abilities in a variety of plants, while demonstrating a lack of specificity that rivals or even surpasses that of arbuscular mycorrhizae. Indeed, these traits thus far appear to characterize a majority of strains belonging to the so-called "clade B" within the Sebacinales (recently re-classified as the Serendipitaceae), raising numerous basic research questions regarding plant-microbe signaling and the evolution of mycorrhizal symbioses. Further, given their proven beneficial impact on plant growth and their apparent but cryptic ubiquity, sebacinoid fungi should be considered as a previously hidden, but amenable and effective microbial tool for enhancing plant productivity and stress tolerance. PMID:26715121

  9. Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production

    PubMed Central

    Odhiambo, Judith A.; Norton, Urszula; Ashilenje, Dennis; Omondi, Emmanuel C.; Norton, Jay B.

    2015-01-01

    Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha-1 in MT and $149.60 ha-1 in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations. PMID:26237404

  10. Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production.

    PubMed

    Odhiambo, Judith A; Norton, Urszula; Ashilenje, Dennis; Omondi, Emmanuel C; Norton, Jay B

    2015-01-01

    Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha(-1) in MT and $149.60 ha(-1) in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations.

  11. Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production.

    PubMed

    Odhiambo, Judith A; Norton, Urszula; Ashilenje, Dennis; Omondi, Emmanuel C; Norton, Jay B

    2015-01-01

    Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize intercropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha(-1) in MT and $149.60 ha(-1) in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations. PMID:26237404

  12. Sugar uptake into kernels of tunicate tassel-seed maize

    SciTech Connect

    Thomas, P.A.; Felker, F.C.; Crawford, C.G. )

    1990-05-01

    A maize (Zea mays L.) strain expressing both the tassel-seed (Ts-5) and tunicate (Tu) characters was developed which produces glume-covered kernels on the tassel, often born on 7-10 mm pedicels. Vigorous plants produce up to 100 such kernels interspersed with additional sessile kernels. This floral unit provides a potentially valuable experimental system for studying sugar uptake into developing maize seeds. When detached kernels (with glumes and pedicel intact) are placed in incubation solution, fluid flows up the pedicel and into the glumes, entering the pedicel apoplast near the kernel base. The unusual anatomical features of this maize strain permit experimental access to the pedicel apoplast with much less possibility of kernel base tissue damage than with kernels excised from the cob. ({sup 14}C)Fructose incorporation into soluble and insoluble fractions of endosperm increased for 8 days. Endosperm uptake of sucrose, fructose, and D-glucose was significantly greater than that of L-glucose. Fructose uptake was significantly inhibited by CCCP, DNP, and PCMBS. These results suggest the presence of an active, non-diffusion component of sugar transport in maize kernels.

  13. The paradox of plows and productivity: an agronomic comparison of cereal grain production under Iroquois hoe culture and European plow culture in the seventeenth and eighteenth centuries.

    PubMed

    Mt Pleasant, Jane

    2011-01-01

    Iroquois maize farmers in the seventeenth and eighteenth centuries produced three to five times more grain per acre than wheat farmers in Europe. The higher productivity of Iroquois agriculture can be attributed to two factors. First, the absence of plows in the western hemisphere allowed Iroquois farmers to maintain high levels of soil organic matter, critical for grain yields. Second, maize has a higher yield potential than wheat because of its C4 photosynthetic pathway and lower protein content. However, tillage alone accounted for a significant portion of the yield advantage of the Iroquois farmers. When the Iroquois were removed from their territories at the end of the eighteenth century, US farmers occupied and plowed these lands. Within fifty years, maize yields in five counties of western New York dropped to less than thirty bushels per acre. They rebounded when US farmers adopted practices that countered the harmful effects of plowing.

  14. Computational identification of genetic subnetwork modules associated with maize defense response to Fusarium verticillioides

    PubMed Central

    2015-01-01

    Background Maize, a crop of global significance, is vulnerable to a variety of biotic stresses resulting in economic losses. Fusarium verticillioides (teleomorph Gibberella moniliformis) is one of the key fungal pathogens of maize, causing ear rots and stalk rots. To better understand the genetic mechanisms involved in maize defense as well as F. verticillioides virulence, a systematic investigation of the host-pathogen interaction is needed. The aim of this study was to computationally identify potential maize subnetwork modules associated with its defense response against F. verticillioides. Results We obtained time-course RNA-seq data from B73 maize inoculated with wild type F. verticillioides and a loss-of-virulence mutant, and subsequently established a computational pipeline for network-based comparative analysis. Specifically, we first analyzed the RNA-seq data by a cointegration-correlation-expression approach, where maize genes were jointly analyzed with known F. verticillioides virulence genes to find candidate maize genes likely associated with the defense mechanism. We predicted maize co-expression networks around the selected maize candidate genes based on partial correlation, and subsequently searched for subnetwork modules that were differentially activated when inoculated with two different fungal strains. Based on our analysis pipeline, we identified four potential maize defense subnetwork modules. Two were directly associated with maize defense response and were associated with significant GO terms such as GO:0009817 (defense response to fungus) and GO:0009620 (response to fungus). The other two predicted modules were indirectly involved in the defense response, where the most significant GO terms associated with these modules were GO:0046914 (transition metal ion binding) and GO:0046686 (response to cadmium ion). Conclusion Through our RNA-seq data analysis, we have shown that a network-based approach can enhance our understanding of the

  15. Genetically engineered crops and pesticide use in U.S. maize and soybeans

    PubMed Central

    Perry, Edward D.; Ciliberto, Federico; Hennessy, David A.; Moschini, GianCarlo

    2016-01-01

    The widespread adoption of genetically engineered (GE) crops has clearly led to changes in pesticide use, but the nature and extent of these impacts remain open questions. We study this issue with a unique, large, and representative sample of plot-level choices made by U.S. maize and soybean farmers from 1998 to 2011. On average, adopters of GE glyphosate-tolerant (GT) soybeans used 28% (0.30 kg/ha) more herbicide than nonadopters, adopters of GT maize used 1.2% (0.03 kg/ha) less herbicide than nonadopters, and adopters of GE insect-resistant (IR) maize used 11.2% (0.013 kg/ha) less insecticide than nonadopters. When pesticides are weighted by the environmental impact quotient, however, we find that (relative to nonadopters) GE adopters used about the same amount of soybean herbicides, 9.8% less of maize herbicides, and 10.4% less of maize insecticides. In addition, the results indicate that the difference in pesticide use between GE and non-GE adopters has changed significantly over time. For both soybean and maize, GT adopters used increasingly more herbicides relative to nonadopters, whereas adopters of IR maize used increasingly less insecticides. The estimated pattern of change in herbicide use over time is consistent with the emergence of glyphosate weed resistance. PMID:27652335

  16. Genetically engineered crops and pesticide use in U.S. maize and soybeans

    PubMed Central

    Perry, Edward D.; Ciliberto, Federico; Hennessy, David A.; Moschini, GianCarlo

    2016-01-01

    The widespread adoption of genetically engineered (GE) crops has clearly led to changes in pesticide use, but the nature and extent of these impacts remain open questions. We study this issue with a unique, large, and representative sample of plot-level choices made by U.S. maize and soybean farmers from 1998 to 2011. On average, adopters of GE glyphosate-tolerant (GT) soybeans used 28% (0.30 kg/ha) more herbicide than nonadopters, adopters of GT maize used 1.2% (0.03 kg/ha) less herbicide than nonadopters, and adopters of GE insect-resistant (IR) maize used 11.2% (0.013 kg/ha) less insecticide than nonadopters. When pesticides are weighted by the environmental impact quotient, however, we find that (relative to nonadopters) GE adopters used about the same amount of soybean herbicides, 9.8% less of maize herbicides, and 10.4% less of maize insecticides. In addition, the results indicate that the difference in pesticide use between GE and non-GE adopters has changed significantly over time. For both soybean and maize, GT adopters used increasingly more herbicides relative to nonadopters, whereas adopters of IR maize used increasingly less insecticides. The estimated pattern of change in herbicide use over time is consistent with the emergence of glyphosate weed resistance.

  17. Accumulation of Hydrocarbons by Maize (Zea mays L.) in Remediation of Soils Contaminated with Crude Oil.

    PubMed

    Liao, Changjun; Xu, Wending; Lu, Guining; Liang, Xujun; Guo, Chuling; Yang, Chen; Dang, Zhi

    2015-01-01

    This study has investigated the use of screened maize for remediation of soil contaminated with crude oil. Pots experiment was carried out for 60 days by transplanting maize seedlings into spiked soils. The results showed that certain amount of crude oil in soil (≤2 147 mg·kg(-1)) could enhance the production of shoot biomass of maize. Higher concentration (6 373 mg·kg(-1)) did not significantly inhibit the growth of plant maize (including shoot and root). Analysis of plant shoot by GC-MS showed that low molecular weight polycyclic aromatic hydrocarbons (PAHs) were detected in maize tissues, but PAHs concentration in the plant did not increase with higher concentration of crude oil in soil. The reduction of total petroleum hydrocarbon in planted soil was up to 52.21-72.84%, while that of the corresponding controls was only 25.85-34.22% in two months. In addition, data from physiological and biochemical indexes demonstrated a favorable adaptability of maize to crude oil pollution stress. This study suggested that the use of maize (Zea mays L.) was a good choice for remediation of soil contaminated with petroleum within a certain range of concentrations.

  18. Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003–2004)

    PubMed Central

    Ortiz-García, S.; Ezcurra, E.; Schoel, B.; Acevedo, F.; Soberón, J.; Snow, A. A.

    2005-01-01

    In 2000, transgenes were detected in local maize varieties (landraces) in the mountains of Oaxaca, Mexico [Quist, D. & Chapela, I. H. (2001) Nature 414, 541–543]. This region is part of the Mesoamerican center of origin for maize (Zea mays L.), and the genetic diversity that is maintained in open-pollinated landraces is recognized as an important genetic resource of great cultural value. The presence of transgenes in landraces was significant because transgenic maize has never been approved for cultivation in Mexico. Here we provide a systematic survey of the frequency of transgenes in currently grown landraces. We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004. We then screened 153,746 sampled seeds for the presence of two transgene elements from the 35S promoter of the cauliflower mosaic virus and the nopaline synthase gene (nopaline synthase terminator) from Agrobacterium tumefaciens. One or both of these transgene elements are present in all transgenic commercial varieties of maize. No transgenic sequences were detected with highly sensitive PCR-based markers, appropriate positive and negative controls, and duplicate samples for DNA extraction. We conclude that transgenic maize seeds were absent or extremely rare in the sampled fields. This study provides a much-needed preliminary baseline for understanding the biological, socioeconomic, and ethical implications of the inadvertent dispersal of transgenes from the United States and elsewhere to local landraces of maize in Mexico. PMID:16093316

  19. Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004).

    PubMed

    Ortiz-García, S; Ezcurra, E; Schoel, B; Acevedo, F; Soberón, J; Snow, A A

    2005-08-30

    In 2000, transgenes were detected in local maize varieties (landraces) in the mountains of Oaxaca, Mexico [Quist, D. & Chapela, I. H. (2001) Nature 414, 541-543]. This region is part of the Mesoamerican center of origin for maize (Zea mays L.), and the genetic diversity that is maintained in open-pollinated landraces is recognized as an important genetic resource of great cultural value. The presence of transgenes in landraces was significant because transgenic maize has never been approved for cultivation in Mexico. Here we provide a systematic survey of the frequency of transgenes in currently grown landraces. We sampled maize seeds from 870 plants in 125 fields and 18 localities in the state of Oaxaca during 2003 and 2004. We then screened 153,746 sampled seeds for the presence of two transgene elements from the 35S promoter of the cauliflower mosaic virus and the nopaline synthase gene (nopaline synthase terminator) from Agrobacterium tumefaciens. One or both of these transgene elements are present in all transgenic commercial varieties of maize. No transgenic sequences were detected with highly sensitive PCR-based markers, appropriate positive and negative controls, and duplicate samples for DNA extraction. We conclude that transgenic maize seeds were absent or extremely rare in the sampled fields. This study provides a much-needed preliminary baseline for understanding the biological, socioeconomic, and ethical implications of the inadvertent dispersal of transgenes from the United States and elsewhere to local landraces of maize in Mexico.

  20. The Effect of Pollination on Cd Phytoextraction From Soil by Maize (Zea mays L.).

    PubMed

    Xu, Wending; Lu, Guining; Wang, Rui; Guo, Chuling; Liao, Changjun; Yi, Xiaoyun; Dang, Zhi

    2015-01-01

    A pot experiment was conducted to investigate the effects of pollination on cadmium (Cd) phytoextraction from soil by mature maize plants. The results showed that the unpollinated maize plants accumulated 50% more Cd than that of the pollinated plants, even though the dry weight of the former plants was 15% less than that of the latter plants. The Cd accumulation in root and leaf of the unpollinated maize plant was 0.47 and 0.89 times higher than that of the pollinated plant, respectively. The Cd concentration in the cob was significantly decreased because of pollination. Preventing pollination is a promising approach for enhancing the effectiveness of phytoextraction in Cd-contaminated soils by maize. This study suggested that in low Cd-contaminated soil pollination should be encouraged because accumulation of Cd in maize grains is very little and maize seeds can bring farmers economic benefits, while in high Cd-contaminated soil, inhibition of pollination can be applied to enhance phytoextraction of Cd from soil by maize plant.

  1. Genetically engineered crops and pesticide use in U.S. maize and soybeans.

    PubMed

    Perry, Edward D; Ciliberto, Federico; Hennessy, David A; Moschini, GianCarlo

    2016-08-01

    The widespread adoption of genetically engineered (GE) crops has clearly led to changes in pesticide use, but the nature and extent of these impacts remain open questions. We study this issue with a unique, large, and representative sample of plot-level choices made by U.S. maize and soybean farmers from 1998 to 2011. On average, adopters of GE glyphosate-tolerant (GT) soybeans used 28% (0.30 kg/ha) more herbicide than nonadopters, adopters of GT maize used 1.2% (0.03 kg/ha) less herbicide than nonadopters, and adopters of GE insect-resistant (IR) maize used 11.2% (0.013 kg/ha) less insecticide than nonadopters. When pesticides are weighted by the environmental impact quotient, however, we find that (relative to nonadopters) GE adopters used about the same amount of soybean herbicides, 9.8% less of maize herbicides, and 10.4% less of maize insecticides. In addition, the results indicate that the difference in pesticide use between GE and non-GE adopters has changed significantly over time. For both soybean and maize, GT adopters used increasingly more herbicides relative to nonadopters, whereas adopters of IR maize used increasingly less insecticides. The estimated pattern of change in herbicide use over time is consistent with the emergence of glyphosate weed resistance. PMID:27652335

  2. Fast-Flowering Mini-Maize: Seed to Seed in 60 Days.

    PubMed

    McCaw, Morgan E; Wallace, Jason G; Albert, Patrice S; Buckler, Edward S; Birchler, James A

    2016-09-01

    Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generations a year are typical. FFMM is the result of a modified double-cross hybrid between four fast-flowering lines: Neuffer's Early ACR (full color), Alexander's Early Early Synthetic, Tom Thumb Popcorn, and Gaspe Flint, followed by selection for early flowering and desirable morphology throughout an 11-generation selfing regime. Lines A and B were derived from different progeny of the initial hybrid, and crosses between Mini-Maize A and B exhibit heterosis. The ancestry of each genomic region of Mini-Maize A and B was inferred from the four founder populations using genotyping by sequencing. Other genetic and genomic tools for these lines include karyotypes for both lines A and B, kernel genetic markers y1 (white endosperm) and R1-scm2 (purple endosperm and embryo) introgressed into Mini-Maize A, and ∼24× whole-genome resequencing data for Mini-Maize A. PMID:27440866

  3. Patterns of Chromosomal Duplication in Maize and Their Implications for Comparative Maps of the Grasses

    PubMed Central

    Gaut, Brandon S.

    2001-01-01

    The maize genome contains extensive chromosomal duplications that probably were produced by an ancient tetraploid event. Comparative cereal maps have identified at least 10 duplicated, or homologous, chromosomal regions within maize. However, the methods used to document chromosomal homologies from comparative maps are not statistical, and their criteria are often unclear. This paper describes the development of a simulation method to test for the statistical significance of marker colinearity between chromosomes, and the application of the method to a molecular map of maize. The method documents colinearity among 24 pairs of maize chromosomes, suggesting homology in maize is more complex than represented by comparative cereal maps. The results also reveal that 60%–82% of the genome has been retained in colinear regions and that as much as a third of the genome could be present in multiple copies. Altogether, the complex pattern of colinearity among maize chromosomes suggests that current comparative cereal maps do not adequately represent the evolution and organization of the maize genome. PMID:11156615

  4. Nearly Identical Paralogs: Implications for Maize (Zea mays L.) Genome Evolution

    PubMed Central

    Emrich, Scott J.; Li, Li; Wen, Tsui-Jung; Yandeau-Nelson, Marna D.; Fu, Yan; Guo, Ling; Chou, Hui-Hsien; Aluru, Srinivas; Ashlock, Daniel A.; Schnable, Patrick S.

    2007-01-01

    As an ancient segmental tetraploid, the maize (Zea mays L.) genome contains large numbers of paralogs that are expected to have diverged by a minimum of 10% over time. Nearly identical paralogs (NIPs) are defined as paralogous genes that exhibit ≥98% identity. Sequence analyses of the “gene space” of the maize inbred line B73 genome, coupled with wet lab validation, have revealed that, conservatively, at least ∼1% of maize genes have a NIP, a rate substantially higher than that in Arabidopsis. In most instances, both members of maize NIP pairs are expressed and are therefore at least potentially functional. Of evolutionary significance, members of many NIP families also exhibit differential expression. The finding that some families of maize NIPs are closely linked genetically while others are genetically unlinked is consistent with multiple modes of origin. NIPs provide a mechanism for the maize genome to circumvent the inherent limitation that diploid genomes can carry at most two “alleles” per “locus.” As such, NIPs may have played important roles during the evolution and domestication of maize and may contribute to the success of long-term selection experiments in this important crop species. PMID:17110490

  5. Efficiency and Inheritance of Targeted Mutagenesis in Maize Using CRISPR-Cas9.

    PubMed

    Zhu, Jinjie; Song, Ning; Sun, Silong; Yang, Weilong; Zhao, Haiming; Song, Weibin; Lai, Jinsheng

    2016-01-20

    CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins) is an adaptive immune system in bacteria and archaea to defend against invasion from foreign DNA fragments. Recently, it has been developed as a powerful targeted genome editing tool for a wide variety of species. However, its application in maize has only been tested with transiently expressed somatic cells or with a limited number of stable transgenic T0 plants. The exact efficiency and specificity of the CRISPR/Cas system in the highly complex maize genome has not been documented yet. Here we report an extensive study of the well-studied type II CRISPR-Cas9 system for targeted genome editing in maize, with the codon-optimized Cas9 protein and the short non-coding guide RNA generated through a functional maize U6 snRNA promoter. Targeted gene mutagenesis was detected for 90 loci by maize protoplast assay, with an average cleavage efficiency of 10.67%. Stable knockout transformants for maize phytoene synthase gene (PSY1) were obtained. Mutations occurred in germ cells can be stably inherited to the next generation. Moreover, no off-target effect was detected at the computationally predicted putative off-target loci. No significant difference between the transcriptomes of the Cas9 expressed and non-expressed lines was detected. Our results confirmed that the CRISPR-Cas9 could be successfully applied as a robust targeted genome editing system in maize.

  6. The Effect of Pollination on Cd Phytoextraction From Soil by Maize (Zea mays L.).

    PubMed

    Xu, Wending; Lu, Guining; Wang, Rui; Guo, Chuling; Liao, Changjun; Yi, Xiaoyun; Dang, Zhi

    2015-01-01

    A pot experiment was conducted to investigate the effects of pollination on cadmium (Cd) phytoextraction from soil by mature maize plants. The results showed that the unpollinated maize plants accumulated 50% more Cd than that of the pollinated plants, even though the dry weight of the former plants was 15% less than that of the latter plants. The Cd accumulation in root and leaf of the unpollinated maize plant was 0.47 and 0.89 times higher than that of the pollinated plant, respectively. The Cd concentration in the cob was significantly decreased because of pollination. Preventing pollination is a promising approach for enhancing the effectiveness of phytoextraction in Cd-contaminated soils by maize. This study suggested that in low Cd-contaminated soil pollination should be encouraged because accumulation of Cd in maize grains is very little and maize seeds can bring farmers economic benefits, while in high Cd-contaminated soil, inhibition of pollination can be applied to enhance phytoextraction of Cd from soil by maize plant. PMID:25581531

  7. Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

    NASA Astrophysics Data System (ADS)

    De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

    2015-04-01

    The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. In addition, biochars offer a simple, sustainable tool for managing organic wastes and to produce added value products. Numerous research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients and by providing other services such as improving soil physical and biological properties [1]. However, the effectiveness of biochar in enhancing plant fertility is a function of soil type, climate, and type of crop [2] but also of the biochar properties. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will not negatively affect soil health and productivity. The major goals of this research were: i) understanding how the properties of 5 different biochars produced by using different feedstock and pyrolysis conditions are related to their agronomic response, and ii) assessing the agronomic effect of biochar amendment under field conditions of a typical Mediterranean non-irrigated plantation. Four of the used biochars were produced by pyrolysis from wood (2), paper sludge (1) and sewage sludge (1), at temperatures up to 620 °C. The fifth biochar was produced from old grapevine wood by applying the traditional kiln method. Biochars were analysed for elemental composition (C, H, N), pH, WHC and ash contents. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by 13C solid-state NMR spectroscopy. The FT-IR spectra indicated the presence of lignin residues in

  8. Relationship between Agronomic Parameters, Phenolic Composition of Grape Skin, and Texture Properties of Vitis vinifera L. cv. Tempranillo.

    PubMed

    García-Estévez, Ignacio; Andrés-García, Paula; Alcalde-Eon, Cristina; Giacosa, Simone; Rolle, Luca; Rivas-Gonzalo, Julián C; Quijada-Morín, Natalia; Escribano-Bailón, M Teresa

    2015-09-01

    The relationship between the agronomic parameters of grapevine and the phenolic composition of skin of Vitis vinifera L. cv. Tempranillo grapes was assessed. The physical and mechanical properties of berries and their skins were also determined and correlated to the chemical composition. Results showed a significant negative correlation between grapevine vigor-related parameters (such as leaf area and bunch weight) and anthocyanin composition, whereas the percentage (w/w) of seeds was negatively correlated with the amount of flavanols of grape skins. Texture properties of grape skins also showed an important relationship with chemical composition. Berry hardness showed a negative correlation with the coumaroyl-anthocyanin derivatives, but it was positively correlated to skin flavanic composition. Moreover, significant regressions with high coefficients of determination were found between phenolic composition and grapevine vigor-related and texture variables, thus pointing out that these parameters might be useful for estimating the phenolic composition of grape skins.

  9. Genetic and agronomic assessment of cob traits in corn under low and normal nitrogen management conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With rising energy demands and costs for fossil fuels, alternative energy from renewable sources such as maize cobs will become competitive. Maize cobs have beneficial characteristics for utilization as feedstock including compact tissue, high cellulose content, and low ash and nitrogen content. Nit...

  10. Betaine Deficiency in Maize 1

    PubMed Central

    Lerma, Claudia; Rich, Patrick J.; Ju, Grace C.; Yang, Wen-Ju; Hanson, Andrew D.; Rhodes, David

    1991-01-01

    Maize (Zea mays L.) is a betaine-accumulating species, but certain maize genotypes lack betaine almost completely; a single recessive gene has been implicated as the cause of this deficiency (D Rhodes, PJ Rich [1988] Plant Physiol 88: 102-108). This study was undertaken to determine whether betaine deficiency in diverse maize germplasm is conditioned by the same genetic locus, and to define the biochemical lesion(s) involved. Complementation tests indicated that all 13 deficient genotypes tested shared a common locus. One maize population (P77) was found to be segregating for betaine deficiency, and true breeding individuals were used to produce related lines with and without betaine. Leaf tissue of both betaine-positive and betaine-deficient lines readily converted supplied betaine aldehyde to betaine, but only the betaine-containing line was able to oxidize supplied choline to betaine. This locates the lesion in betaine-deficient plants at the choline → betaine aldehyde step of betaine synthesis. Consistent with this location, betaine-deficient plants were shown to have no detectable endogenous pool of betaine aldehyde. PMID:16668098

  11. Enhanced Virus Resistance in Transgenic Maize Expressing a dsRNA-Specific Endoribonuclease Gene from E. coli

    PubMed Central

    Liu, He; Tian, Lanzhi; Zhang, Aihong; Zhang, Yanjing; Shi, Lindan; Guo, Bihong; Xu, Jin; Duan, Xifei; Wang, Xianbing; Han, Chenggui; Miao, Hongqin; Yu, Jialin; Li, Dawei

    2013-01-01

    Maize rough dwarf disease (MRDD), caused by several Fijiviruses in the family Reoviridae, is a global disease that is responsible for substantial yield losses in maize. Although some maize germplasm have low levels of polygenic resistance to MRDD, highly resistant cultivated varieties are not available for agronomic field production in China. In this work, we have generated transgenic maize lines that constitutively express rnc70, a mutant E. coli dsRNA-specific endoribonuclease gene. Transgenic lines were propagated and screened under field conditions for 12 generations. During three years of evaluations, two transgenic lines and their progeny were challenged with Rice black-streaked dwarf virus (RBSDV), the causal agent of MRDD in China, and these plants exhibited reduced levels of disease severity. In two normal years of MRDD abundance, both lines were more resistant than non-transgenic plants. Even in the most serious MRDD year, six out of seven progeny from one line were resistant, whereas non-transgenic plants were highly susceptible. Molecular approaches in the T12 generation revealed that the rnc70 transgene was integrated and expressed stably in transgenic lines. Under artificial conditions permitting heavy virus inoculation, the T12 progeny of two highly resistant lines had a reduced incidence of MRDD and accumulation of RBSDV in infected plants. In addition, we confirmed that the RNC70 protein could bind directly to RBSDV dsRNA in vitro. Overall, our data show that RNC70-mediated resistance in transgenic maize can provide efficient protection against dsRNA virus infection. PMID:23593318

  12. Sewage sludge hydrochars: properties and agronomic impact as related to different production conditions

    NASA Astrophysics Data System (ADS)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Conte, Pellegrino; Knicker, Heike

    2015-04-01

    amount of hydrochar equivalent to 5 and 25 t ha-1 were prepared in quadruplicate for each hydrochar using Lolium perenne as test plant (25 seeds per pot). Hydrochars were not washed before this experiment. Control pots, without hydrochar amendment, were also settled for comparison purposes (n=6). After adjusting the soil humidity to 60% of the maximum WHC, the pots were placed into a greenhouse under similar conditions than those reported by [3]. In this experiment germination, survival rates and biomass production per pot were measured periodically. Elemental analysis and the determination of several chemical properties of hydrochars such as pH, electrical conductivity and ash content were performed. Additionally, 13C solid-state nuclear magnetic resonance (NMR) was applied to elucidate the main chemical groups whereas fast field cycling (FFC) NMR relaxometry was valuable for investigating the porous structure and water dynamic in the different hydrochars. This work confirmed that production conditions of hydrochars vary their chemical properties and hence their agronomic effect. Biomass production raised significantly in presence of all hydrochars, being the response in presence of hydrochars produced at 200˚C significantly higher than the response in presence of hydrochars produced at 260˚C, whereas the residence time of the hydrochars in the reactor did not affect biomass productivity. Concerning the characterization data, hydrochars which showed the highest biomass production were those which contain the highest mineralized nitrogen content (NH4, NO2 and NO3) and a greater presence of alkyl carbons and carboxyl groups. Hydrochars FFC NMR relaxometry results show a lower T1 (longitudinal relaxation time) compared to the pure sewage sludge, which suggests that HTC processes reduced the average pore size of the system. This has further implications in the water and nutrient retention capacity of the hydrochars compared to the pure sewage sludge. Acknowledgements: The

  13. Enantioselective Phytotoxicity of Imazamox Against Maize Seedlings.

    PubMed

    Wei, Jing; Zhang, Xiaoxiao; Li, Xuesheng; Zeng, Dongqiang; Tan, Huihua

    2016-02-01

    There is increasing concern about the enantioselective effects of chiral herbicides. To study the enantioselective toxicity of the chiral herbicide imazamox on maize, maize seedlings (Zhengda 619, Zea mays L.) were exposed to imazamox racemate and enantiomers in hydroponic experiments. The results showed that imazamox enantiomers selectively affected maize. The effective concentration of Rac-, S- and R-imazamox that caused 50 % inhibition after 5 days treatments (EC50,5d) were 0.4212, 1.2142 and 0.2460 mg L(-1), respectively, for maize root length; 0.0002, 0.1005, 0.0032 mg L(-1), respectively, for maize root fresh weight; 0.7114, 1.4056 and 0.4530 mg L(-1), respectively, for maize shoot height; 0.6220, 1.5418, 0.2286 mg L(-1), respectively, for maize shoot fresh weight; and 0.1100, 0.3306, 0.0307 mg L(-1), respectively, for the total chlorophyll content of leaves. The root morphological parameters and root activity reflected the toxicity effects in the order R-imazamox > Rac-imazamox > S-imazamox. Maize roots were more sensitive to imazamox than maize shoots. The chiral herbicide imazamox poses enantioselective phytotoxicity on maize seedlings: the order of toxicity is R-imazamox > Rac-imazamox > S-imazamox. PMID:26508428

  14. [Effect of plant density on population yield and economic output value in maize-soybean intercropping].

    PubMed

    Zhu, Yuan-gang; Gao, Feng-ju; Cao, Peng-peng; Wang, Le-zheng

    2015-06-01

    The effects of plant density on population yield and economic output value in maize and soybean intercropping were studied with the design of the double saturated D-optimal regression. A mathematical model was developed, in which the densities of maize and soybean were independent variables, and population grain yield, dry matter accumulation and economic output value were dependent variables, respectively. The result showed that the plant density significantly affected the population grain yield, dry matter accumulation and economic output value, and the effects of density of maize on population indices were greater than those of density of soybean. Under the low level conditions of density, the population grain yield, dry matter accumulation and economic output value increased with the density of maize and soybean. The maximum population grain yield was 8101.31 kg · hm(-2) the optimized combination of 72023 plant maize · hm(-2) and 99924 plant soybean · hm(-2), while the maximum population dry matter accumulation was 15282.45 kg · hm(-2) with the optimized combination of 75000 plant maize · hm(-2) and 93372 plant soybean · hm(-2), and the maximum population economic output value was 23494.50 Yuan · hm(-2) with the optimized combination of 73758 plant maize · hm(-2) and 87597 plant soybean · hm(-2). The optimum combination of densities of maize and soybean calculated by computer were 58554-71547 plant · hm(-2) for maize and 82217-100303 plant · hm(-2) for soybean in order to obtain grain yield greater than 7500 kg · hm(-2), dry matter accumulation greater than 14250 kg · hm(-2) and economic output value greater 22500 yuan · hm(-2) under the condition of this experiment.

  15. Local post-harvest practices associated with aflatoxin and fumonisin contamination of maize in three agro ecological zones of Tanzania.

    PubMed

    Kamala, Analice; Kimanya, Martin; Haesaert, Geert; Tiisekwa, Bendantuguka; Madege, Richard; Degraeve, Szanne; Cyprian, Cypriana; De Meulenaer, Bruno

    2016-01-01

    A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg(-1) for AF and from 49 to 18 273 μg kg(-1) for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania.

  16. Population structure of the African Clawed Frog (Xenopus laevis) in maize-growing areas with atrazine application versus non-maize-growing areas in South Africa

    USGS Publications Warehouse

    Du Preez, L.H.; Solomon, K.R.; Carr, J.A.; Giesy, J.P.; Gross, T.S.; Kendall, R.J.; Smith, E.E.; Van Der Kraak, G. L.; Weldon, C.

    2005-01-01

    The herbicide atrazine has been suggested to cause gonadal deformities in frogs and could possibly impact on reproduction. Since the early 1960s, atrazine has been used in large amounts in maize production areas of South Africa. These areas overlap with populations of the African Clawed Frog (Xenopus laevis) that has a wide distribution in southern Africa and is found in most water-bodies including those where atrazine residues are detected. The aim of this study was to compare various attributes of individual- and population-level responses of X. laevis from maize-growing and non-maize-growing areas. Xenopus laevis were studied in three reference and five maize-growing sites. Sex ratio, snout-vent length, body-mass and age profiles were found to be similar for populations in maize-growing and non-maize-growing areas. Our mark-recapture data indicated that all sites had robust populations. There were no significant relationships between exposure to atrazine and any of the parameters investigated in populations of X. laevis.

  17. A farm-level analysis of economic and agronomic impacts of gradual climate warming

    SciTech Connect

    Kaiser, H.M.; Sampath, R.; Riha, S.J.; Wilks, D.S.; Rossiter, D.G.

    1993-05-01

    The potential economic and agronomic impacts of gradual climate warming are examined at the farm level. Three models of the relevant climatic, agronomic, and economic processes are developed and linked to address climate change impacts and agricultural adaptability. Several climate warming severity. The results indicate that grain farmers in southern Minnesota can effectively adapt to a gradually changing climate (warmer and either wetter or drier) by adopting later maturing cultivars, changing crop mix, and altering the timing of field operations to take advantage of a longer growing season resulting from climate warming.

  18. Soil Type and Maize Cultivar Affect the Genetic Diversity of Maize Root-Associated Burkholderia cepacia Populations.

    PubMed

    Dalmastri; Chiarini; Cantale; Bevivino; Tabacchioni

    1999-10-01

    Abstract Burkholderia cepacia populations associated with the Zea mays root system were investigated to assess the influence of soil type, maize cultivar, and root localization on the degree of their genetic diversity. A total of 180 B. cepacia isolates were identified by restriction analysis of the amplified 16S rDNA (ARDRA technique). The genetic diversity among B. cepacia isolates was analyzed by the random amplified polymorphic DNA (RAPD) technique, using the 10-mer primer AP5. The analysis of molecular variance (AMOVA) method was applied to estimate the variance components for the RAPD patterns. The results indicated that, among the factors studied, the soil was clearly the dominant one in affecting the genetic diversity of maize root-associated B. cepacia populations. In fact, the percentage of variation among populations was significantly higher between B. cepacia populations recovered from maize planted in different soils than between B. cepacia populations isolated from different maize cultivars and from distinct root compartments such as rhizoplane and rhizosphere. The analysis of the genetic relationships among B. cepacia isolates resulted in dendrograms showing bacterial populations with frequent recombinations and a nonclonal genetic structure. The dendrograms were also in agreement with the AMOVA results. We were able to group strains obtained from distinct soils on the basis of their origin, confirming that soil type had the major effect on the degree of genetic diversity of the maize root-associated B. cepacia populations analyzed. On the other hand, strains isolated from distinct root compartments exhibited a random distribution which confirmed that the rhizosphere and rhizoplane populations analyzed did not significantly differ in their genetic structure.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p273.html

  19. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing

    PubMed Central

    Correa-Galeote, David; Bedmar, Eulogio J.; Fernández-González, Antonio J.; Fernández-López, Manuel; Arone, Gregorio J.

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  20. Bacterial Communities in the Rhizosphere of Amilaceous Maize (Zea mays L.) as Assessed by Pyrosequencing.

    PubMed

    Correa-Galeote, David; Bedmar, Eulogio J; Fernández-González, Antonio J; Fernández-López, Manuel; Arone, Gregorio J

    2016-01-01

    Maize (Zea mays L.) is the staple diet of the native peasants in the Quechua region of the Peruvian Andes who continue growing it in small plots called chacras following ancestral traditions. The abundance and structure of bacterial communities associated with the roots of amilaceous maize has not been studied in Andean chacras. Accordingly, the main objective of this study was to describe the rhizospheric bacterial diversity of amilaceous maize grown either in the presence or the absence of bur clover cultivated in soils from the Quechua maize belt. Three 16S rRNA gene libraries, one corresponding to sequences of bacteria from bulk soil of a chacra maintained under fallow conditions, the second from the rhizosphere of maize-cultivated soils, and the third prepared from rhizospheric soil of maize cultivated in intercropping with bur clover were examined using pyrosequencing tags spanning the V4 and V5 hypervariable regions of the gene. A total of 26031 sequences were found that grouped into 5955 distinct operational taxonomic units which distributed in 309 genera. The numbers of OTUs in the libraries from the maize-cultivated soils were significantly higher than those found in the libraries from bulk soil. One hundred ninety seven genera were found in the bulk soil library and 234 and 203 were in those from the maize and maize/bur clover-cultivated soils. Sixteen out of the 309 genera had a relative abundance higher than 0.5% and the were (in decreasing order of abundance) Gp4, Gp6, Flavobacterium, Subdivision3 genera incertae sedis of the Verrucomicrobia phylum, Gemmatimonas, Dechloromonas, Ohtaekwangia, Rhodoferax, Gaiella, Opitutus, Gp7, Spartobacteria genera incertae sedis, Terrimonas, Gp5, Steroidobacter and Parcubacteria genera incertae sedis. Genera Gp4 and Gp6 of the Acidobacteria, Gemmatimonas and Rhodoferax were the most abundant in bulk soil, whereas Flavobacterium, Dechloromonas and Ohtaekwangia were the main genera in the rhizosphere of maize

  1. MaizeGDB: Global support for maize research through open access information [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the open-access global repository for maize genetic and genomic information – from single genes that determine nutritional quality to whole genome-scale data for complex traits including yield and drought tolerance. The data and tools at MaizeGDB enable researchers from Ethiopia to Ghan...

  2. Kernel Composition, Starch Structure, and Enzyme Digestibility of Opaque-2 Maize and Quality Protein Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives of this study were to understand how opaque-2 (o2) mutation and quality protein maize (QPM) affect maize kernel composition and starch structure, property, and enzyme digestibility. Kernels of o2 maize contained less protein (9.6−12.5%) than those of the wild-type (WT) counterparts (12...

  3. Combined Linkage and Association Mapping Reveals QTL and Candidate Genes for Plant and Ear Height in Maize.

    PubMed

    Li, Xiaopeng; Zhou, Zijian; Ding, Junqiang; Wu, Yabin; Zhou, Bo; Wang, Ruixia; Ma, Jinliang; Wang, Shiwei; Zhang, Xuecai; Xia, Zongliang; Chen, Jiafa; Wu, Jianyu

    2016-01-01

    Plant height (PH) and ear height (EH) are two very important agronomic traits related to the population density and lodging in maize. In order to better understand of the genetic basis of nature variation in PH and EH, two bi-parental populations and one genome-wide association study (GWAS) population were used to map quantitative trait loci (QTL) for both traits. Phenotypic data analysis revealed a wide normal distribution and high heritability for PH and EH in the three populations, which indicated that maize height is a highly polygenic trait. A total of 21 QTL for PH and EH in three common genomic regions (bin 1.05, 5.04/05, and 6.04/05) were identified by QTL mapping in the two bi-parental populations under multiple environments. Additionally, 41 single nucleotide polymorphisms (SNPs) were identified for PH and EH by GWAS, of which 29 SNPs were located in 19 unique candidate gene regions. Most of the candidate genes were related to plant growth and development. One QTL on Chromosome 1 was further verified in a near-isogenic line (NIL) population, and GWAS identified a C2H2 zinc finger family protein that maybe the candidate gene for this QTL. These results revealed that nature variation of PH and EH are strongly controlled by multiple genes with low effect and facilitated a better understanding of the underlying mechanism of height in maize.

  4. Combined Linkage and Association Mapping Reveals QTL and Candidate Genes for Plant and Ear Height in Maize.

    PubMed

    Li, Xiaopeng; Zhou, Zijian; Ding, Junqiang; Wu, Yabin; Zhou, Bo; Wang, Ruixia; Ma, Jinliang; Wang, Shiwei; Zhang, Xuecai; Xia, Zongliang; Chen, Jiafa; Wu, Jianyu

    2016-01-01

    Plant height (PH) and ear height (EH) are two very important agronomic traits related to the population density and lodging in maize. In order to better understand of the genetic basis of nature variation in PH and EH, two bi-parental populations and one genome-wide association study (GWAS) population were used to map quantitative trait loci (QTL) for both traits. Phenotypic data analysis revealed a wide normal distribution and high heritability for PH and EH in the three populations, which indicated that maize height is a highly polygenic trait. A total of 21 QTL for PH and EH in three common genomic regions (bin 1.05, 5.04/05, and 6.04/05) were identified by QTL mapping in the two bi-parental populations under multiple environments. Additionally, 41 single nucleotide polymorphisms (SNPs) were identified for PH and EH by GWAS, of which 29 SNPs were located in 19 unique candidate gene regions. Most of the candidate genes were related to plant growth and development. One QTL on Chromosome 1 was further verified in a near-isogenic line (NIL) population, and GWAS identified a C2H2 zinc finger family protein that maybe the candidate gene for this QTL. These results revealed that nature variation of PH and EH are strongly controlled by multiple genes with low effect and facilitated a better understanding of the underlying mechanism of height in maize. PMID:27379126

  5. Expression of ZmLEC1 and ZmWRI1 increases seed oil production in maize.

    PubMed

    Shen, Bo; Allen, William B; Zheng, Peizhong; Li, Changjiang; Glassman, Kimberly; Ranch, Jerry; Nubel, Douglas; Tarczynski, Mitchell C

    2010-07-01

    Increasing seed oil production is a major goal for global agriculture to meet the strong demand for oil consumption by humans and for biodiesel production. Previous studies to increase oil synthesis in plants have focused mainly on manipulation of oil pathway genes. As an alternative to single-enzyme approaches, transcription factors provide an attractive solution for altering complex traits, with the caveat that transcription factors may face the challenge of undesirable pleiotropic effects. Here, we report that overexpression of maize (Zea mays) LEAFY COTYLEDON1 (ZmLEC1) increases seed oil by as much as 48% but reduces seed germination and leaf growth in maize. To uncouple oil increase from the undesirable agronomic traits, we identified a LEC1 downstream transcription factor, maize WRINKLED1 (ZmWRI1). Overexpression of ZmWRI1 results in an oil increase similar to overexpression of ZmLEC1 without affecting germination, seedling growth, or grain yield. These results emphasize the importance of field testing for developing a commercial high-oil product and highlight ZmWRI1 as a promising target for increasing oil production in crops.

  6. Combined Linkage and Association Mapping Reveals QTL and Candidate Genes for Plant and Ear Height in Maize

    PubMed Central

    Li, Xiaopeng; Zhou, Zijian; Ding, Junqiang; Wu, Yabin; Zhou, Bo; Wang, Ruixia; Ma, Jinliang; Wang, Shiwei; Zhang, Xuecai; Xia, Zongliang; Chen, Jiafa; Wu, Jianyu

    2016-01-01

    Plant height (PH) and ear height (EH) are two very important agronomic traits related to the population density and lodging in maize. In order to better understand of the genetic basis of nature variation in PH and EH, two bi-parental populations and one genome-wide association study (GWAS) population were used to map quantitative trait loci (QTL) for both traits. Phenotypic data analysis revealed a wide normal distribution and high heritability for PH and EH in the three populations, which indicated that maize height is a highly polygenic trait. A total of 21 QTL for PH and EH in three common genomic regions (bin 1.05, 5.04/05, and 6.04/05) were identified by QTL mapping in the two bi-parental populations under multiple environments. Additionally, 41 single nucleotide polymorphisms (SNPs) were identified for PH and EH by GWAS, of which 29 SNPs were located in 19 unique candidate gene regions. Most of the candidate genes were related to plant growth and development. One QTL on Chromosome 1 was further verified in a near-isogenic line (NIL) population, and GWAS identified a C2H2 zinc finger family protein that maybe the candidate gene for this QTL. These results revealed that nature variation of PH and EH are strongly controlled by multiple genes with low effect and facilitated a better understanding of the underlying mechanism of height in maize. PMID:27379126

  7. Agro-potentiality of distillery effluent on soil and agronomical characteristics of Abelmoschus esculentus L. (okra).

    PubMed

    Chopra, A K; Srivastava, Sachin; Kumar, Vinod; Pathak, Chakresh

    2013-08-01

    The present study showed that irrigation of soil with different effluent concentrations (10, 25, 50, 75, and 100 %) of distillery effluent (DE) for 60 days resulted in significant (P < 0.001) changes in moisture content; electrical conductivity (EC), pH, chlorides (Cl(-)), total organic carbon (TOC), exchangeable sodium (Na(+)), available potassium (K(+)), calcium (Ca(2+)), magnesium (Mg(2+)), iron (Fe(2+)), total Kjeldahl nitrogen (TKN), available phosphorus (P), and sulfate (SO4 (2-)) of soil. The non-significant (P > 0.05) changes were observed for water-holding capacity and bulk density of the soil. Among various concentrations of DE irrigation, irrigation with 100 % effluent concentration increased moisture content, (24.85 %), EC (77.88 %), Cl(-) (285.95 %), TOC (3,171.42 %), exchangeable Na(+) (241.04 %), available K(+) (52.49 %), Ca(2+) (990.37 %), Mg(2+) (1,751.72 %), TKN (1,417.00 %), available P (305.00 %), and SO4 (2-) (75.32 %) in the soil and decreased pH (-20.22 %). The more stimulation in agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, fresh weight, chlorophyll content, leaf area index, and crop yield of A. esculentus were observed to be inversely proportional to the concentration of effluent water, with the best results being obtained at a dilution of 25 % of DE concentration.

  8. Effects of airborne black carbon pollution on maize

    NASA Astrophysics Data System (ADS)

    Illes, Bernadett; Anda, Angela; Soos, Gabor

    2013-04-01

    The black carbon (BC) changes the radiation balance of the Earth and contributes to global warming. The airborne BC deposited on the surface of plant, changing the radiation balance, water balance and the total dry matter (TDM) content of plant. The objective of our study was to investigate the impact of soot originated from motor vehicle exhaust on maize. The field experiment was carried out in Keszthely Agrometeorological Research Station (Hungary) in three consecutive years (2010, 2011, 2012) of growing season. The test plant was the maize hybrid Sperlona (FAO 340) with short growing season. The BC was chemically "pure", which means that it is free any contaminants (e.g. heavy metals). The BC was coming from the Hankook Tyre Company (Dunaújváros, Hungary), where used that for improve the wear resistance of tires. We used a motorised sprayer of SP 415 type to spray the BC onto the leaf surface. The leaf area index (LAI) was measured each week on the same 12 sample maize in each treatment using an LI 3000A automatic planimeter (LI-COR, Lincoln, NE). Albedo was measured by pyranometers of the CMA-11 type (Kipp & Zonen, Vaisala), what we placed the middle of the plot of 0.3 ha. The effects of BC were studied under two different water supplies: evapotranspirometers of Thornthwaite type were used for "ad libitum" treatment and rainfed treatment in field plots. In 2010 and 2012, a big difference was not observed in the case of LAI in the effects of BC. However, in 2011 there was a significant difference. The LAI of the BC polluted maize was higher (10-15%, P<0.05), than the LAI of the control maize in the rainfed plot and in the ET chambers, respectively. The albedo of the BC contaminated maize decreased (15-30%, P<0.05) in all three years. We also detected that the green plant surface of maize increased on BC contaminated treatment. These results may suggest that the plant is able to absorb the additional carbon source through the leaves. The albedo decreased

  9. Phosphorus quantity-intensity relationships and agronomic measures of P in surface layers of soil from a long-term slurry experiment.

    PubMed

    Anderson, R; Wu, Y

    2001-01-01

    Soils from a long-term slurry experiment established in 1970 at Hillsborough, Northern Ireland, were used in the experiment. The site has a clay loam soil overlying Silurian shale. Seven treatments were used with three replicate plots per treatment. Control plots were treated with mineral fertiliser supplying 200 kg N, 32 kg P and 160 kg K ha(-1) yr(-1). Slurry treatment plots were in two blocks and treated with either pig or cow slurry supplied at 50, 100 or 200 m3 ha(-1) yr(-1). Agronomic measures of P determined on 10-cm soil cores were compared with measured P quantity/intensity (Q/I) parameters from fitted sorption and desorption isotherms. Phosphorus affinity constant was found to be significantly and negatively correlated with P loading of soils. Desorption rate coefficient also increased significantly with increase in P loading from slurry, although there was no significant difference between slurry types (cow vs. pig). In contrast, while agronomic measures of P (water-soluble P, Olsen P, calcium chloride-extractable P, degree of P saturation (DPS)) also correlated significantly with P loading and total P (TP) in the soils, there was a separation and significant differences between the cow and pig slurry treatment blocks, with the former being much lower. Phosphorus inputs to pig slurry treated plots were much higher than to equivalent cow slurry plots over the first 15 years of the study but declined sharply over the most recent 10 years to more or less par. Conventional measures of agronomic P such as Olsen P and DPS, measure only P accumulation over the longer term and indicated only the higher content of P accumulating in soil of pig slurry treatments. Risk of P loss estimated by Q/I parameters appeared to show very similar behaviour between the two slurry types in line with more recent manurial additions but in contradiction of P accumulation statistics.

  10. The Use of Targeted Marker Subsets to Account for Population Structure and Relatedness in Genome-Wide Association Studies of Maize (Zea mays L.).

    PubMed

    Chen, Angela H; Lipka, Alexander E

    2016-01-01

    A typical plant genome-wide association study (GWAS) uses a mixed linear model (MLM) that includes a trait as the response variable, a marker as an explanatory variable, and fixed and random effect covariates accounting for population structure and relatedness. Although effective in controlling for false positive signals, this model typically fails to detect signals that are correlated with population structure or are located in high linkage disequilibrium (LD) genomic regions. This result likely arises from each tested marker being used to estimate population structure and relatedness. Previous work has demonstrated that it is possible to increase the power of the MLM by estimating relatedness (i.e., kinship) with markers that are not located on the chromosome where the tested marker resides. To quantify the amount of additional significant signals one can expect using this so-called K_chr model, we reanalyzed Mendelian, polygenic, and complex traits in two maize (Zea mays L.) diversity panels that have been previously assessed using the traditional MLM. We demonstrated that the K_chr model could find more significant associations, especially in high LD regions. This finding is underscored by our identification of novel genomic signals proximal to the tocochromanol biosynthetic pathway gene ZmVTE1 that are associated with a ratio of tocotrienols. We conclude that the K_chr model can detect more intricate sources of allelic variation underlying agronomically important traits, and should therefore become more widely used for GWAS. To facilitate the implementation of the K_chr model, we provide code written in the R programming language. PMID:27233668

  11. The Use of Targeted Marker Subsets to Account for Population Structure and Relatedness in Genome-Wide Association Studies of Maize (Zea mays L.)

    PubMed Central

    Chen, Angela H.; Lipka, Alexander E.

    2016-01-01

    A typical plant genome-wide association study (GWAS) uses a mixed linear model (MLM) that includes a trait as the response variable, a marker as an explanatory variable, and fixed and random effect covariates accounting for population structure and relatedness. Although effective in controlling for false positive signals, this model typically fails to detect signals that are correlated with population structure or are located in high linkage disequilibrium (LD) genomic regions. This result likely arises from each tested marker being used to estimate population structure and relatedness. Previous work has demonstrated that it is possible to increase the power of the MLM by estimating relatedness (i.e., kinship) with markers that are not located on the chromosome where the tested marker resides. To quantify the amount of additional significant signals one can expect using this so-called K_chr model, we reanalyzed Mendelian, polygenic, and complex traits in two maize (Zea mays L.) diversity panels that have been previously assessed using the traditional MLM. We demonstrated that the K_chr model could find more significant associations, especially in high LD regions. This finding is underscored by our identification of novel genomic signals proximal to the tocochromanol biosynthetic pathway gene ZmVTE1 that are associated with a ratio of tocotrienols. We conclude that the K_chr model can detect more intricate sources of allelic variation underlying agronomically important traits, and should therefore become more widely used for GWAS. To facilitate the implementation of the K_chr model, we provide code written in the R programming language. PMID:27233668

  12. Genetic control of morphometric diversity in the maize shoot apical meristem

    PubMed Central

    Leiboff, Samuel; Li, Xianran; Hu, Heng-Cheng; Todt, Natalie; Yang, Jinliang; Li, Xiao; Yu, Xiaoqing; Muehlbauer, Gary J.; Timmermans, Marja C. P.; Yu, Jianming; Schnable, Patrick S.; Scanlon, Michael J.

    2015-01-01

    The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate genes. Analyses of candidate genes implicated in hormone transport, cell division and cell size confirm correlations between SAM morphology and trait-associated SNP alleles. Our data illustrate that the microscopic seedling SAM is predictive of adult phenotypes and that SAM morphometric variation is associated with genes not previously predicted to regulate SAM size. PMID:26584889

  13. Discovering functional modules across diverse maize transcriptomes using COB, the Co-expression Browser.

    PubMed

    Schaefer, Robert J; Briskine, Roman; Springer, Nathan M; Myers, Chad L

    2014-01-01

    Tools that provide improved ability to relate genotype to phenotype have the potential to accelerate breeding for desired traits and to improve our understanding of the molecular variants that underlie phenotypes. The availability of large-scale gene expression profiles in maize provides an opportunity to advance our understanding of complex traits in this agronomically important species. We built co-expression networks based on genome-wide expression data from a variety of maize accessions as well as an atlas of different tissues and developmental stages. We demonstrate that these networks reveal clusters of genes that are enriched for known biological function and contain extensive structure which has yet to be characterized. Furthermore, we found that co-expression networks derived from developmental or tissue atlases as compared to expression variation across diverse accessions capture unique functions. To provide convenient access to these networks, we developed a public, web-based Co-expression Browser (COB), which enables interactive queries of the genome-wide networks. We illustrate the utility of this system through two specific use cases: one in which gene-centric queries are used to provide functional context for previously characterized metabolic pathways, and a second where lists of genes produced by mapping studies are further resolved and validated using co-expression networks.

  14. Discovering functional modules across diverse maize transcriptomes using COB, the Co-expression Browser.

    PubMed

    Schaefer, Robert J; Briskine, Roman; Springer, Nathan M; Myers, Chad L

    2014-01-01

    Tools that provide improved ability to relate genotype to phenotype have the potential to accelerate breeding for desired traits and to improve our understanding of the molecular variants that underlie phenotypes. The availability of large-scale gene expression profiles in maize provides an opportunity to advance our understanding of complex traits in this agronomically important species. We built co-expression networks based on genome-wide expression data from a variety of maize accessions as well as an atlas of different tissues and developmental stages. We demonstrate that these networks reveal clusters of genes that are enriched for known biological function and contain extensive structure which has yet to be characterized. Furthermore, we found that co-expression networks derived from developmental or tissue atlases as compared to expression variation across diverse accessions capture unique functions. To provide convenient access to these networks, we developed a public, web-based Co-expression Browser (COB), which enables interactive queries of the genome-wide networks. We illustrate the utility of this system through two specific use cases: one in which gene-centric queries are used to provide functional context for previously characterized metabolic pathways, and a second where lists of genes produced by mapping studies are further resolved and validated using co-expression networks. PMID:24922320

  15. Haploid formation in maize, barley, flax, and potato.

    PubMed

    Pret'ová, A; Obert, B; Bartosová, Z

    2006-08-01

    The article is reviewing some significant features and issues in the process of haploid formation in two important monocotyledonous crop plants - maize and barley - and in two dicotyledonous plants - flax and potato. Exotic maize lines with higher androgenic response turned up as a good source for this heritable trait and this valuable trait can be incorporated into elite maize lines via crossing. Lots of attempts were devoted to identifying some cytological and/or morphological markers for androgenic response in maize microspore cultures. The "starlike" organization of the cytoplasm inside the induced maize microspores together with the enlarged size of induced microspores can be considered as morphological markers for androgenic response. In barley, microspores with rich cytoplasm that was of granular appearance with the nucleus located near the cell wall and with no visible vacuole had the largest survival rate and many of these cells continued in development and produced embryos. In flax, a dramatic increase of induction rate in anther cultures (up to 25%) was achieved when flax anthers were pretreated for 3 days at 4 degrees C and afterwards kept for 1 day at 35 degrees C. Also gynogenesis in flax has been reported already and complete plants were obtained. In potato microspore cultures, formation of two dissimilar cells indicated a strong polarization in the system and as a result of this polarization a prominent suspensor developed that persisted until the torpedo stage of the androgenic embryo. This was the first time the formation of a well developed suspensor was described in connection with androgenesis.

  16. Analysis of Maize versus Ethanol Production in Nebraska, United States and International Agricultural Droughts: Lessons for Global Food Security

    NASA Astrophysics Data System (ADS)

    Boken, V.; Tenkorang, F.

    2012-04-01

    Nebraska is one of the eight main corn (maize) belt states of the United States. Maize is the major crop of Nebraska with an average annual production of about 38 million tons (about 12% of U.S. production), which contributes billions of dollars to the state's economy. The yield of maize has increased significantly over the past century - from 1.6 t/ha in 1900 to 10.4 t/ha in 2010. While the majority of maize (about 40%) is currently used for animal feed and ethanol production, only about six percent is exported. It is estimated that about one billion people accounting for about 15% population of the world live in chronic hunger because of low agricultural productivity and drought. Most of these people depend on the U.S. for grains including maize. If a greater quantity of maize is diverted to ethanol production, considerably less quantity of maize would be available for export to developing countries where it could be used for human consumption and to mitigate hunger and improve food security. This paper presents analysis of maize production in Nebraska for the past three decades and examines how its commercialization for ethanol production has affected its exports in the face of drought at an international level.

  17. MaizeGDB becomes 'sequence-centric'.

    PubMed

    Sen, Taner Z; Andorf, Carson M; Schaeffer, Mary L; Harper, Lisa C; Sparks, Michael E; Duvick, Jon; Brendel, Volker P; Cannon, Ethalinda; Campbell, Darwin A; Lawrence, Carolyn J

    2009-01-01

    MaizeGDB is the maize research community's central repository for genetic and genomic information about the crop plant and research model Zea mays ssp. mays. The MaizeGDB team endeavors to meet research needs as they evolve based on researcher feedback and guidance. Recent work has focused on better integrating existing data with sequence information as it becomes available for the B73, Mo17 and Palomero Toluqueño genomes. Major endeavors along these lines include the implementation of a genome browser to graphically represent genome sequences; implementation of POPcorn, a portal ancillary to MaizeGDB that offers access to independent maize projects and will allow BLAST similarity searches of participating projects' data sets from a single point; and a joint MaizeGDB/PlantGDB project to involve the maize community in genome annotation. In addition to summarizing recent achievements and future plans, this article also discusses specific examples of community involvement in setting priorities and design aspects of MaizeGDB, which should be of interest to other database and resource providers seeking to better engage their users. MaizeGDB is accessible online at http://www.maizegdb.org.Database URL:http://www.maizegdb.org.

  18. Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant Inbred Line Population.

    PubMed

    Wen, Weiwei; Li, Kun; Alseekh, Saleh; Omranian, Nooshin; Zhao, Lijun; Zhou, Yang; Xiao, Yingjie; Jin, Min; Yang, Ning; Liu, Haijun; Florian, Alexandra; Li, Wenqiang; Pan, Qingchun; Nikoloski, Zoran; Yan, Jianbing; Fernie, Alisdair R

    2015-07-01

    Deciphering the influence of genetics on primary metabolism in plants will provide insights useful for genetic improvement and enhance our fundamental understanding of plant growth and development. Although maize (Zea mays) is a major crop for food and feed worldwide, the genetic architecture of its primary metabolism is largely unknown. Here, we use high-density linkage mapping to dissect large-scale metabolic traits measured in three different tissues (leaf at seedling stage, leaf at reproductive stage, and kernel at 15 d after pollination [DAP]) of a maize recombinant inbred line population. We identify 297 quantitative trait loci (QTLs) with moderate (86.2% of the mapped QTL, R(2) = 2.4 to 15%) to major effects (13.8% of the mapped QTL, R(2) >15%) for 79 primary metabolites across three tissues. Pairwise epistatic interactions between these identified loci are detected for more than 25.9% metabolites explaining 6.6% of the phenotypic variance on average (ranging between 1.7 and 16.6%), which implies that epistasis may play an important role for some metabolites. Key candidate genes are highlighted and mapped to carbohydrate metabolism, the tricarboxylic acid cycle, and several important amino acid biosynthetic and catabolic pathways, with two of them being further validated using candidate gene association and expression profiling analysis. Our results reveal a metabolite-metabolite-agronomic trait network that, together with the genetic determinants of maize primary metabolism identified herein, promotes efficient utilization of metabolites in maize improvement. PMID:26187921

  19. Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant Inbred Line Population[OPEN

    PubMed Central

    Wen, Weiwei; Li, Kun; Alseekh, Saleh; Omranian, Nooshin; Zhao, Lijun; Zhou, Yang; Xiao, Yingjie; Jin, Min; Yang, Ning; Liu, Haijun; Florian, Alexandra; Li, Wenqiang; Pan, Qingchun; Nikoloski, Zoran; Yan, Jianbing; Fernie, Alisdair R.

    2015-01-01

    Deciphering the influence of genetics on primary metabolism in plants will provide insights useful for genetic improvement and enhance our fundamental understanding of plant growth and development. Although maize (Zea mays) is a major crop for food and feed worldwide, the genetic architecture of its primary metabolism is largely unknown. Here, we use high-density linkage mapping to dissect large-scale metabolic traits measured in three different tissues (leaf at seedling stage, leaf at reproductive stage, and kernel at 15 d after pollination [DAP]) of a maize recombinant inbred line population. We identify 297 quantitative trait loci (QTLs) with moderate (86.2% of the mapped QTL, R2 = 2.4 to 15%) to major effects (13.8% of the mapped QTL, R2 >15%) for 79 primary metabolites across three tissues. Pairwise epistatic interactions between these identified loci are detected for more than 25.9% metabolites explaining 6.6% of the phenotypic variance on average (ranging between 1.7 and 16.6%), which implies that epistasis may play an important role for some metabolites. Key candidate genes are highlighted and mapped to carbohydrate metabolism, the tricarboxylic acid cycle, and several important amino acid biosynthetic and catabolic pathways, with two of them being further validated using candidate gene association and expression profiling analysis. Our results reveal a metabolite-metabolite-agronomic trait network that, together with the genetic determinants of maize primary metabolism identified herein, promotes efficient utilization of metabolites in maize improvement. PMID:26187921

  20. Maize Genotype and Food Matrix Affect the Provitamin A Carotenoid Bioefficacy from Staple and Carrot-fortified Feeds in Mongolian Gerbils (Meriones unguiculatus)

    PubMed Central

    Schmaelzle, Samantha; Gannon, Bryan; Crawford, Serra; Arscott, Sara A.; Goltz, Shellen; Palacios-Rojas, Natalia; Pixley, Kevin V.; Simon, Philipp W.; Tanumihardjo, Sherry A.

    2014-01-01

    Biofortification to increase provitamin A carotenoids is an agronomic approach to alleviate vitamin A deficiency. Two studies compared biofortified foods using in vitro and in vivo methods. Study 1 screened maize genotypes (n = 44) using in vitro analysis, which demonstrated decreasing micellarization with increasing provitamin A. Thereafter, seven 50% biofortified maize feeds that hypothesized a one-to-one equivalency between β-cryptoxanthin and β-carotene were fed to Mongolian gerbils. Total liver retinol differed among the maize groups (P = 0.0043). Study 2 assessed provitamin A bioefficacy from 0.5% high-carotene carrots added to 60% staple-food feeds, followed by in vitro screening. Liver retinol was highest in the potato and banana groups, maize group retinol did not differ from baseline, and all treatments differed from control (P < 0.0001). In conclusion, β-cryptoxanthin and β-carotene have similar bioefficacy; meal matrix effects influence provitamin A absorption from carrot; and in vitro micellarization does not predict bioefficacy. PMID:24341827

  1. Maize genotype and food matrix affect the provitamin A carotenoid bioefficacy from staple and carrot-fortified feeds in Mongolian gerbils (Meriones unguiculatus).

    PubMed

    Schmaelzle, Samantha; Gannon, Bryan; Crawford, Serra; Arscott, Sara A; Goltz, Shellen; Palacios-Rojas, Natalia; Pixley, Kevin V; Simon, Philipp W; Tanumihardjo, Sherry A

    2014-01-01

    Biofortification to increase provitamin A carotenoids is an agronomic approach to alleviate vitamin A deficiency. Two studies compared biofortified foods using in vitro and in vivo methods. Study 1 screened maize genotypes (n = 44) using in vitro analysis, which demonstrated decreasing micellarization with increasing provitamin A. Thereafter, seven 50% biofortified maize feeds that hypothesized a one-to-one equivalency between β-cryptoxanthin and β-carotene were fed to Mongolian gerbils. Total liver retinol differed among the maize groups (P = 0.0043). Study 2 assessed provitamin A bioefficacy from 0.5% high-carotene carrots added to 60% staple-food feeds, followed by in vitro screening. Liver retinol was highest in the potato and banana groups, maize group retinol did not differ from baseline, and all treatments differed from control (P < 0.0001). In conclusion, β-cryptoxanthin and β-carotene have similar bioefficacy; meal matrix effects influence provitamin A absorption from carrot; and in vitro micellarization does not predict bioefficacy.

  2. Transcriptome Analysis of Cadmium-Treated Roots in Maize (Zea mays L.)

    PubMed Central

    Yue, Runqing; Lu, Caixia; Qi, Jianshuang; Han, Xiaohua; Yan, Shufeng; Guo, Shulei; Liu, Lu; Fu, Xiaolei; Chen, Nana; Yin, Haiyan; Chi, Haifeng; Tie, Shuanggui

    2016-01-01

    Cadmium (Cd) is a heavy metal and is highly toxic to all plant species. However, the underlying molecular mechanism controlling the effects of auxin on the Cd stress response in maize is largely unknown. In this study, the transcriptome produced by maize ‘Zheng 58’ root responses to Cd stress was sequenced using Illumina sequencing technology. In our study, six RNA-seq libraries yielded a total of 244 million clean short reads and 30.37 Gb of sequence data. A total of 6342 differentially expressed genes (DEGs) were grouped into 908 Gene Ontology (GO) categories and 198 Kyoto Encyclopedia of Genes and Genomes terms. GO term enrichment analysis indicated that various auxin signaling pathway-related GO terms were significantly enriched in DEGs. Comparison of the transcript abundances for auxin biosynthesis, transport, and downstream response genes revealed a universal expression response under Cd treatment. Furthermore, our data showed that free indole-3-acetic acid (IAA) levels were significantly reduced; but IAA oxidase activity was up-regulated after Cd treatment in maize roots. The analysis of Cd activity in maize roots under different Cd and auxin conditions confirmed that auxin affected Cd accumulation in maize seedlings. These results will improve our understanding of the complex molecular mechanisms underlying the response to Cd stress in maize roots.

  3. Transcriptome Analysis of Cadmium-Treated Roots in Maize (Zea mays L.)

    PubMed Central

    Yue, Runqing; Lu, Caixia; Qi, Jianshuang; Han, Xiaohua; Yan, Shufeng; Guo, Shulei; Liu, Lu; Fu, Xiaolei; Chen, Nana; Yin, Haiyan; Chi, Haifeng; Tie, Shuanggui

    2016-01-01

    Cadmium (Cd) is a heavy metal and is highly toxic to all plant species. However, the underlying molecular mechanism controlling the effects of auxin on the Cd stress response in maize is largely unknown. In this study, the transcriptome produced by maize ‘Zheng 58’ root responses to Cd stress was sequenced using Illumina sequencing technology. In our study, six RNA-seq libraries yielded a total of 244 million clean short reads and 30.37 Gb of sequence data. A total of 6342 differentially expressed genes (DEGs) were grouped into 908 Gene Ontology (GO) categories and 198 Kyoto Encyclopedia of Genes and Genomes terms. GO term enrichment analysis indicated that various auxin signaling pathway-related GO terms were significantly enriched in DEGs. Comparison of the transcript abundances for auxin biosynthesis, transport, and downstream response genes revealed a universal expression response under Cd treatment. Furthermore, our data showed that free indole-3-acetic acid (IAA) levels were significantly reduced; but IAA oxidase activity was up-regulated after Cd treatment in maize roots. The analysis of Cd activity in maize roots under different Cd and auxin conditions confirmed that auxin affected Cd accumulation in maize seedlings. These results will improve our understanding of the complex molecular mechanisms underlying the response to Cd stress in maize roots. PMID:27630647

  4. Transcriptome Analysis of Cadmium-Treated Roots in Maize (Zea mays L.).

    PubMed

    Yue, Runqing; Lu, Caixia; Qi, Jianshuang; Han, Xiaohua; Yan, Shufeng; Guo, Shulei; Liu, Lu; Fu, Xiaolei; Chen, Nana; Yin, Haiyan; Chi, Haifeng; Tie, Shuanggui

    2016-01-01

    Cadmium (Cd) is a heavy metal and is highly toxic to all plant species. However, the underlying molecular mechanism controlling the effects of auxin on the Cd stress response in maize is largely unknown. In this study, the transcriptome produced by maize 'Zheng 58' root responses to Cd stress was sequenced using Illumina sequencing technology. In our study, six RNA-seq libraries yielded a total of 244 million clean short reads and 30.37 Gb of sequence data. A total of 6342 differentially expressed genes (DEGs) were grouped into 908 Gene Ontology (GO) categories and 198 Kyoto Encyclopedia of Genes and Genomes terms. GO term enrichment analysis indicated that various auxin signaling pathway-related GO terms were significantly enriched in DEGs. Comparison of the transcript abundances for auxin biosynthesis, transport, and downstream response genes revealed a universal expression response under Cd treatment. Furthermore, our data showed that free indole-3-acetic acid (IAA) levels were significantly reduced; but IAA oxidase activity was up-regulated after Cd treatment in maize roots. The analysis of Cd activity in maize roots under different Cd and auxin conditions confirmed that auxin affected Cd accumulation in maize seedlings. These results will improve our understanding of the complex molecular mechanisms underlying the response to Cd stress in maize roots. PMID:27630647

  5. Fate of genetically modified maize DNA in the oral cavity and rumen of sheep.

    PubMed

    Duggan, Paula S; Chambers, Philip A; Heritage, John; Michael Forbes, J

    2003-02-01

    The polymerase chain reaction (PCR) technique was used to investigate the fate of a transgene in the rumen of sheep fed silage and maize grains from an insect-resistant maize line. A 1914-bp DNA fragment containing the entire coding region of the synthetic cryIA(b) gene was still amplifiable from rumen fluid sampled 5 h after feeding maize grains. The same target sequence, however, could not be amplified from rumen fluid sampled from sheep fed silage prepared from the genetically modified maize line. PCR amplification of a shorter (211-bp), yet still highly specific, target sequence was possible with rumen fluid sampled up to 3 and 24 h after feeding silage and maize grains, respectively. These findings indicate that intact transgenes from silage are unlikely to survive significantly in the rumen since a DNA sequence 211-bp long is very unlikely to transmit genetic information. By contrast, DNA in maize grains persists for a significant time and may, therefore, provide a source of transforming DNA in the rumen. In addition, we have examined the biological activity of plasmid DNA that had previously been exposed to the ovine oral cavity. Plasmid extracted from saliva sampled after incubation for 8 min was still capable of transforming competent Escherichia coli to kanamycin resistance, implying that DNA released from the diet within the mouth may retain sufficient biological activity for the transformation of competent oral bacteria.

  6. Refuge or Reservoir? The Potential Impacts of the Biofuel Crop Miscanthus x giganteus on a Major Pest of Maize

    PubMed Central

    Spencer, Joseph L.; Raghu, S.

    2009-01-01

    Background Interest in the cultivation of biomass crops like the C4 grass Miscanthus x giganteus (Miscanthus) is increasing as global demand for biofuel grows. In the US, Miscanthus is promoted as a crop well-suited to the Corn Belt where it could be cultivated on marginal land interposed with maize and soybean. Interactions (direct and indirect) of Miscanthus, maize, and the major Corn Belt pest of maize, the western corn rootworm, (Diabrotica virgifera virgifera LeConte, WCR) are unknown. Adding a perennial grass/biomass crop to this system is concerning since WCR is adapted to the continuous availability of its grass host, maize (Zea mays). Methodology/Principal Findings In a greenhouse and field study, we investigated WCR development and oviposition on Miscanthus. The suitability of Miscanthus for WCR development varied across different WCR populations. Data trends indicate that WCR populations that express behavioural resistance to crop rotation performed as well on Miscanthus as on maize. Over the entire study, total adult WCR emergence from Miscanthus (212 WCR) was 29.6% of that from maize (717 WCR). Adult dry weight was 75–80% that of WCR from maize; female emergence patterns on Miscanthus were similar to females developing on maize. There was no difference in the mean no. of WCR eggs laid at the base of Miscanthus and maize in the field. Conclusions/Significance Field oviposition and significant WCR emergence from Miscanthus raises many questions about the nature of likely interactions between Miscanthus, maize and WCR and the potential for Miscanthus to act as a refuge or reservoir for Corn Belt WCR. Responsible consideration of the benefits and risks associated with Corn Belt Miscanthus are critical to protecting an agroecosystem that we depend on for food, feed, and increasingly, fuel. Implications for European agroecosystems in which Miscanthus is being proposed are also discussed in light of the WCR's recent invasion into Europe. PMID:20016814

  7. [Effects of nitrogen fertilization and root separation on the plant growth and grain yield of maize and its rhizosphere microorganisms].

    PubMed

    Zhang, Xiang-Qian; Huang, Guo-Qin; Bian, Xin-Min; Zhao, Qi-Guo

    2012-12-01

    A field experiment with root separation was conducted to study the effects of root interaction in maize-soybean intercropping system on the plant growth and grain yield of maize and its rhizosphere microorganisms under different nitrogen fertilization levels (0.1, 0.3, 0.5, and 0.7 g x kg(-1)). Root interaction and nitrogen fertilization had positive effects on the plant height, leaf length and width, and leaf chlorophyll content of maize. Less difference was observed in the root dry mass of maize at maturing stage between the treatments root separation and no root separation. However, as compared with root separation, no root separation under the nitrogen fertilization levels 0.1, 0.3, 0.5, and 0.7 g x kg(-1) increased the biomass per maize plant by 8.8%, 6.3%, 3.6%, and 0.7%, and the economic yield per maize plant by 17.7%, 10.0%, 8.2%, and 0.9%, respectively. No root separation increased the quantity of rhizosphere fungi and azotobacteria significantly, as compared with root separation. With increasing nitrogen fertilization level, the quantity of rhizosphere bacteria, fungi, and actinomycetes presented an increasing trend, while that of rhizosphere azotobacteria decreased after an initial increase. The root-shoot ratio of maize at maturing stage was significantly negatively correlated with the quantity of rhizosphere bacteria, fungi, and actinomycetes, but less correlated with the quantity of rhizosphere azotobacteria. It was suggested that the root interaction in maize-soybean intercropping system could improve the plant growth of maize and increase the maize yield and rhizosphere microbial quantity, but the effect would be decreased with increasing nitrogen fertilization level.

  8. Identification of Maize Genes Associated with Host Plant Resistance or Susceptibility to Aspergillus flavus Infection and Aflatoxin Accumulation

    PubMed Central

    Kelley, Rowena Y.; Williams, W. Paul; Mylroie, J. Erik; Boykin, Deborah L.; Harper, Jonathan W.; Windham, Gary L.; Ankala, Arunkanth; Shan, Xueyan

    2012-01-01

    Background Aspergillus flavus infection and aflatoxin contamination of maize pose negative impacts in agriculture and health. Commercial maize hybrids are generally susceptible to this fungus. Significant levels of host plant resistance have been observed in certain maize inbred lines. This study was conducted to identify maize genes associated with host plant resistance or susceptibility to A. flavus infection and aflatoxin accumulation. Results Genome wide gene expression levels with or without A. flavus inoculation were compared in two resistant maize inbred lines (Mp313E and Mp04∶86) in contrast to two susceptible maize inbred lines (Va35 and B73) by microarray analysis. Principal component analysis (PCA) was used to find genes contributing to the larger variances associated with the resistant or susceptible maize inbred lines. The significance levels of gene expression were determined by using SAS and LIMMA programs. Fifty candidate genes were selected and further investigated by quantitative RT-PCR (qRT-PCR) in a time-course study on Mp313E and Va35. Sixteen of the candidate genes were found to be highly expressed in Mp313E and fifteen in Va35. Out of the 31 highly expressed genes, eight were mapped to seven previously identified quantitative trait locus (QTL) regions. A gene encoding glycine-rich RNA binding protein 2 was found to be associated with the host hypersensitivity and susceptibility in Va35. A nuclear pore complex protein YUP85-like gene was found to be involved in the host resistance in Mp313E. Conclusion Maize genes associated with host plant resistance or susceptibility were identified by a combination of microarray analysis, qRT-PCR analysis, and QTL mapping methods. Our findings suggest that multiple mechanisms are involved in maize host plant defense systems in response to Aspergillus flavus infection and aflatoxin accumulation. These findings will be important in identification of DNA markers for breeding maize lines resistant to

  9. Cultivar x binary mixture interaction effect on agronomic traits in orchardgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate and characterize the agronomic value, including dry matter yield and forage quality of 25 orchardgrass cultivars grown in monoculture and binary mixtures with alfalfa under supplemental irrigation from 2009 to 2012 at a Millville, UT, field site. Orchardgrass monoc...

  10. Genome-wide association study of agronomic traits in common bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genome-wide association study (GWAS) using a global Andean diversity panel (ADP) of 237 genotypes of common bean, Phaseolus vulgaris was conducted to gain insight into the genetic architecture of several agronomic traits controlling phenology, biomass, yield components and seed yield. The panel wa...

  11. Sewage sludge fertiliser use: implications for soil and plant copper evolution in forest and agronomic soils.

    PubMed

    Ferreiro-Domínguez, Nuria; Rigueiro-Rodríguez, Antonio; Mosquera-Losada, M Rosa

    2012-05-01

    Fertilisation with sewage sludge may lead to crop toxicity and environmental degradation. This study aims to evaluate the effects of two types of soils (forest and agronomic), two types of vegetation (unsown (coming from soil seed bank) and sown), and two types of fertilisation (sludge fertilisation and mineral fertilisation, with a no fertiliser control) in afforested and treeless swards and in sown and unsown forestlands on the total and available Cu concentration in soil, the leaching of this element and the Cu levels in plant. The experimental design was completely randomised with nine treatments and three replicates. Fertilisation with sewage sludge increased the concentration of Cu in soil and plant, but the soil values never exceeded the maximum set by Spanish regulations. Sewage sludge inputs increased both the total and Mehlich 3 Cu concentrations in agronomic soils and the Cu levels in plant developed in agronomic and forest soils, with this effect pronounced in the unsown swards of forest soils. Therefore, the use of high quality sewage sludge as fertiliser may improve the global productivity of forest, agronomic and silvopastoral systems without creating environmental hazards. PMID:22425275

  12. A survey of the agronomic and end-use characteristics of low phytic acid soybeans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With unique high protein and oil contents, soybean (Glycine max L. merr.) is one of the most widely grown agronomic crops in the United States. Around 98% of those soybeans are used in animal feeds ranging from swine and cattle to domestic animals and aquaculture. This chapter will introduce phytic ...

  13. Agronomic effects of mutations in two soybean Stearoyl-ACP-Desaturases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] oil normally contains 2-4% stearic acid. Oil with higher levels of stearic acid is desired for use in the baking industry, for both its chemical properties and human health benefits. Several lines with increased stearic acid have been identified; however, the agronom...

  14. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 20 commercially available peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2015 for agronomic traits (crop value, yield, seed grade, and characteristics). Environmental conditions in 2015 were not favorable for Sclerotinia blight, southern bl...

  15. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 23 commercially available peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2014 for agronomic traits (crop value, yield, seed grade, and characteristics) and resistance to soilborne diseases. Among the 16 runner entries evaluated, Tamrun OL11...

  16. Association mapping of agronomic and quality traits in USDA pea single-plant collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Association mapping is an efficient approach for the identification of the molecular basis of agronomic traits in crop plants. For this purpose in pea (Pisum sativum L.), we genotyped and phenotyped individual lines of the single-plant derived core collection of the USDA pea single-plant (PSP) colle...

  17. The iojap gene in maize

    SciTech Connect

    Martienssen, Robert

    2001-12-01

    The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

  18. The role of maize root size in phosphorus uptake and productivity of maize/faba bean and maize/wheat intercropping systems.

    PubMed

    Zhang, Yikai; Chen, Fanjun; Li, Long; Chen, Yanhua; Liu, Bingran; Zhou, Yuling; Yuan, Lixing; Zhang, Fusuo; Mi, Guohua

    2012-11-01

    Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulation of maize root growth could improve the productivity of the two intercropping systems. Two near isogenic maize hybrids (the larger-rooted T149 and smaller-rooted T222) were intercropped with faba bean and wheat, under conditions of high- and low-P availability. The larger-rooted T149 showed greater competitive ability than the smaller-rooted T222 in both maize/faba bean and maize/wheat intercropping systems. The higher competitive ability of T149 improved the productivity of the maize/faba bean intercropping system in P-sufficient conditions. In maize/wheat intercropping systems, root growth, shoot biomass, and P uptake of maize were inhibited by wheat, regardless of the P-supply. Compared with T222, the larger-rooted T149 suffered less in the intercropping systems. The total biomass of the maize/wheat intercropping system was higher for wheat/T149 than for wheat/T222 under low-P conditions. These data suggested that genetic improvement of maize root size could enhance maize growth and its ability to compete for P resources in maize/faba bean and maize/wheat intercropping systems. In addition, depending on the P availability, larger maize roots could increase the productivity of intercropping systems.

  19. Functional Potential of Soil Microbial Communities in the Maize Rhizosphere

    PubMed Central

    Xiong, Jingbo; Li, Jiabao; He, Zhili; Zhou, Jizhong; Yannarell, Anthony C.; Mackie, Roderick I.

    2014-01-01

    Microbial communities in the rhizosphere make significant contributions to crop health and nutrient cycling. However, their ability to perform important biogeochemical processes remains uncharacterized. Here, we identified important functional genes that characterize the rhizosphere microbial community to understand metabolic capabilities in the maize rhizosphere using the GeoChip-based functional gene array method. Significant differences in functional gene structure were apparent between rhizosphere and bulk soil microbial communities. Approximately half of the detected gene families were significantly (p<0.05) increased in the rhizosphere. Based on the detected gyrB genes, Gammaproteobacteria, Betaproteobacteria, Firmicutes, Bacteroidetes and Cyanobacteria were most enriched in the rhizosphere compared to those in the bulk soil. The rhizosphere niche also supported greater functional diversity in catabolic pathways. The maize rhizosphere had significantly enriched genes involved in carbon fixation and degradation (especially for hemicelluloses, aromatics and lignin), nitrogen fixation, ammonification, denitrification, polyphosphate biosynthesis and degradation, sulfur reduction and oxidation. This research demonstrates that the maize rhizosphere is a hotspot of genes, mostly originating from dominant soil microbial groups such as Proteobacteria, providing functional capacity for the transformation of labile and recalcitrant organic C, N, P and S compounds. PMID:25383887

  20. Somatically segregating clone of apomictic maize-tripsacum hybrid

    SciTech Connect

    Yudin, B.F.; Lukina, L.A.

    1988-11-01

    The results of further study on clone AM-5, isolated in the progeny of /gamma/-irradiated plants of the apomictic hybrid of maize with tripsacum (2n = 38) are reported. The variegated-leaf seedlings of the clone segregate somatically and produce variegated, mottled, green (phenotypically normal) plants in different ratios in the apomictic progenies. The variegated, and to a lesser degree, green segregants segregate further. The mottled apomictics as well as mottled branches of variegated seedlings maintain their phenotype on transplantation, however, these is a progressive enhancement of the characters of vegetative lethality. Lethals of two extra maize genomes to the AM-5 nucleus does not affect significantly the scope and nature of segregation. At the same time, the loss of tripsacum genome restores normal phenotype. Clone AM-5 is an example of hybrid apomictic form causing significant morphological variability, which is, nevertheless, not related with apomictic and reversion to the sexual process.

  1. RNA Polymerases of Maize: Nuclear RNA Polymerases*

    PubMed Central

    Strain, Gustave C.; Mullinix, Kathleen P.; Bogorad, Lawrence

    1971-01-01

    Two DNA-dependent RNA polymerases of nuclear origin have been purified from leaves of Zea mays. The two enzymes can be separated on DEAE-cellulose columns. Enzymes I and II are eluted with 0.08 and 0.20 M (NH4)2SO4, respectively. Both enzymes prefer maize nuclear DNA as a template; they are also more active in the presence of Mg++ than Mn++ and are inhibited by (NH4)2-SO4 or KCl. Neither enzyme is inhibited by rifamycin SV. Enzyme II is strongly inhibited by α-amanitin, whereas enzyme I is not significantly affected. Their ability to use native and denatured DNA as templates varies according to the extent and method of purification of the polymerase. Furthermore, enzyme II can be resolved by DEAE-chromatography or glycerol-gradient centrifugation into two components, one of which prefers native DNA, while the other prefers denatured DNA. PMID:5288239

  2. Molecular and Morpho-Agronomical Characterization of Root Architecture at Seedling and Reproductive Stages for Drought Tolerance in Wheat.

    PubMed

    Tomar, Ram Sewak Singh; Tiwari, Sushma; Vinod; Naik, Bhojaraja K; Chand, Suresh; Deshmukh, Rupesh; Mallick, Niharika; Singh, Sanjay; Singh, Nagendra Kumar; Tomar, S M S

    2016-01-01

    Water availability is a major limiting factor for wheat (Triticum aestivum L.) production in rain-fed agricultural systems worldwide. Root architecture is important for water and nutrition acquisition for all crops, including wheat. A set of 158 diverse wheat genotypes of Australian (72) and Indian (86) origin were studied for morpho-agronomical traits in field under irrigated and drought stress conditions during 2010-11 and 2011-12.Out of these 31 Indian wheat genotypes comprising 28 hexaploid (Triticum aestivum L.) and 3 tetraploid (T. durum) were characterized for root traits at reproductive stage in polyvinyl chloride (PVC) pipes. Roots of drought tolerant genotypes grew upto137cm (C306) as compared to sensitive one of 63cm with a mean value of 94.8cm. Root architecture traits of four drought tolerant (C306, HW2004, HD2888 and NI5439) and drought sensitive (HD2877, HD2012, HD2851 and MACS2496) genotypes were also observed at 6 and 9 days old seedling stage. The genotypes did not show any significant variation for root traits except for longer coleoptiles and shoot and higher absorptive surface area in drought tolerant genotypes. The visible evaluation of root images using WinRhizo Tron root scanner of drought tolerant genotype HW2004 indicated compact root system with longer depth while drought sensitive genotype HD2877 exhibited higher horizontal root spread and less depth at reproductive stage. Thirty SSR markers were used to study genetic variation which ranged from 0.12 to 0.77 with an average value of 0.57. The genotypes were categorized into three subgroups as highly tolerant, sensitive, moderately sensitive and tolerant as intermediate group based on UPGMA cluster, STRUCTURE and principal coordinate analyses. The genotypic clustering was positively correlated to grouping based on root and morpho-agronomical traits. The genetic variability identified in current study demonstrated these traits can be used to improve drought tolerance and association

  3. Molecular and Morpho-Agronomical Characterization of Root Architecture at Seedling and Reproductive Stages for Drought Tolerance in Wheat

    PubMed Central

    Vinod; Naik, Bhojaraja K.; Chand, Suresh; Deshmukh, Rupesh; Mallick, Niharika; Singh, Sanjay; Singh, Nagendra Kumar; Tomar, S. M. S.

    2016-01-01

    Water availability is a major limiting factor for wheat (Triticum aestivum L.) production in rain-fed agricultural systems worldwide. Root architecture is important for water and nutrition acquisition for all crops, including wheat. A set of 158 diverse wheat genotypes of Australian (72) and Indian (86) origin were studied for morpho-agronomical traits in field under irrigated and drought stress conditions during 2010–11 and 2011-12.Out of these 31 Indian wheat genotypes comprising 28 hexaploid (Triticum aestivum L.) and 3 tetraploid (T. durum) were characterized for root traits at reproductive stage in polyvinyl chloride (PVC) pipes. Roots of drought tolerant genotypes grew upto137cm (C306) as compared to sensitive one of 63cm with a mean value of 94.8cm. Root architecture traits of four drought tolerant (C306, HW2004, HD2888 and NI5439) and drought sensitive (HD2877, HD2012, HD2851 and MACS2496) genotypes were also observed at 6 and 9 days old seedling stage. The genotypes did not show any significant variation for root traits except for longer coleoptiles and shoot and higher absorptive surface area in drought tolerant genotypes. The visible evaluation of root images using WinRhizo Tron root scanner of drought tolerant genotype HW2004 indicated compact root system with longer depth while drought sensitive genotype HD2877 exhibited higher horizontal root spread and less depth at reproductive stage. Thirty SSR markers were used to study genetic variation which ranged from 0.12 to 0.77 with an average value of 0.57. The genotypes were categorized into three subgroups as highly tolerant, sensitive, moderately sensitive and tolerant as intermediate group based on UPGMA cluster, STRUCTURE and principal coordinate analyses. The genotypic clustering was positively correlated to grouping based on root and morpho-agronomical traits. The genetic variability identified in current study demonstrated these traits can be used to improve drought tolerance and association

  4. Agronomic assessment of the wheat semi-dwarfing gene Rht8 in contrasting nitrogen treatments and water regimes

    PubMed Central

    Kowalski, Ania M.; Gooding, Mike; Ferrante, Ariel; Slafer, Gustavo A.; Orford, Simon; Gasperini, Debora; Griffiths, Simon

    2016-01-01

    Reduced height 8 (Rht8) is the main alternative to the GA-insensitive Rht alleles in hot and dry environments where it reduces plant height without yield penalty. The potential of Rht8 in northern-European wheat breeding remains unclear, since the close linkage with the photoperiod-insensitive allele Ppd-D1a is unfavourable in the relatively cool summers. In the present study, two near-isogenic lines (NILs) contrasting for the Rht8/tall allele from Mara in a UK-adapted and photoperiod-sensitive wheat variety were evaluated in trials with varying nitrogen fertiliser (N) treatments and water regimes across sites in the UK and Spain. The Rht8 introgression was associated with a robust height reduction of 11% regardless of N treatment and water regime and the Rht8 NIL was more resistant to root-lodging at agronomically-relevant N levels than the tall NIL. In the UK with reduced solar radiation over the growing season than the site in Spain, the Rht8 NIL showed a 10% yield penalty at standard agronomic N levels due to concomitant reduction in grain number and spike number whereas grain weight and harvest index were not significantly different to the tall NIL. The yield penalty associated with the Rht8 introgression was overcome at low N and in irrigated conditions in the UK, and in the high-temperature site in Spain. Decreased spike length and constant spikelet number in the Rht8 NIL resulted in spike compaction of 15%, independent of N and water regime. The genetic interval of Rht8 overlaps with the compactum gene on 2DS, raising the possibility of the same causative gene. Further genetic dissection of these loci is required. PMID:27212788

  5. Forages and Pastures Symposium: development of and field experience with drought-tolerant maize.

    PubMed

    Soderlund, S; Owens, F N; Fagan, C

    2014-07-01

    Drought-tolerant maize hybrids currently are being marketed by several seed suppliers. Such hybrids were developed by phenotypic and marker-assisted selection or through genetic modification and tested by exposing these hybrids to various degrees of water restriction. As drought intensifies, crop yields and survival progressively decline. Water need differs among plants due to differences in root structure, evaporative loss, capacity to store water or enter temporary dormancy, and plant genetics. Availability of water differs widely not only with rainfall and irrigation but also with numerous soil and agronomic factors (e.g., soil type, slope, seeding rates, tillage practices). Reduced weed competition, enhanced pollen shed and silk production, and deep, robust root growth help to reduce the negative impacts of drought. Selected drought-tolerant maize hybrids have consistently yielded more grain even when drought conditions are not apparent either due to reduced use of soil water reserves before water restriction or due to greater tolerance of intermittent water shortages. In DuPont Pioneer trials, whole plant NDF digestibility of maize increased with water restriction, perhaps due to an increased leaf to stem ratio. Efficiency of water use, measured as dry matter or potential milk yield from silage per unit of available water, responded quadratically to water restriction, first increasing slightly but then decreasing as water restriction increased. For grain production, water restriction has its greatest negative impact during or after silking through reducing the number of kernels and reducing kernel filling. For silage production, water restriction during the vegetative growth stage negatively impacts plant height and biomass yield. Earlier planting and shorter season maize hybrids help to avoid midsummer heat stress during pollination and can reduce the number of irrigation events needed. Although drought tolerance of maize hybrids has been improved due to

  6. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus

    PubMed Central

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A. P.; Wittkop, Benjamin; Snowdon, Rod J.; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations. PMID:27066036

  7. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus.

    PubMed

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A P; Wittkop, Benjamin; Snowdon, Rod J; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations.

  8. Agronomic and Seed Quality Traits Dissected by Genome-Wide Association Mapping in Brassica napus.

    PubMed

    Körber, Niklas; Bus, Anja; Li, Jinquan; Parkin, Isobel A P; Wittkop, Benjamin; Snowdon, Rod J; Stich, Benjamin

    2016-01-01

    In Brassica napus breeding, traits related to commercial success are of highest importance for plant breeders. However, such traits can only be assessed in an advanced developmental stage. Molecular markers genetically linked to such traits have the potential to accelerate the breeding process of B. napus by marker-assisted selection. Therefore, the objectives of this study were to identify (i) genome regions associated with the examined agronomic and seed quality traits, (ii) the interrelationship of population structure and the detected associations, and (iii) candidate genes for the revealed associations. The diversity set used in this study consisted of 405 B. napus inbred lines which were genotyped using a 6K single nucleotide polymorphism (SNP) array and phenotyped for agronomic and seed quality traits in field trials. In a genome-wide association study, we detected a total of 112 associations between SNPs and the seed quality traits as well as 46 SNP-trait associations for the agronomic traits with a P < 1.28e-05 (Bonferroni correction of α = 0.05) for the inbreds of the spring and winter trial. For the seed quality traits, a single SNP-sulfur concentration in seeds (SUL) association explained up to 67.3% of the phenotypic variance, whereas for the agronomic traits, a single SNP-blossom color (BLC) association explained up to 30.2% of the phenotypic variance. In a basic local alignment search tool (BLAST) search within a distance of 2.5 Mbp around these SNP-trait associations, 62 hits of potential candidate genes with a BLAST-score of ≥100 and a sequence identity of ≥70% to A. thaliana or B. rapa could be found for the agronomic SNP-trait associations and 187 hits of potential candidate genes for the seed quality SNP-trait associations. PMID:27066036

  9. High-Throughput Sequence-Based Analysis of the Intestinal Microbiota of Weanling Pigs Fed Genetically Modified MON810 Maize Expressing Bacillus thuringiensis Cry1Ab (Bt Maize) for 31 Days

    PubMed Central

    Buzoianu, Stefan G.; Walsh, Maria C.; Rea, Mary C.; O'Sullivan, Orla; Cotter, Paul D.; Ross, R. Paul; Lawlor, Peadar G.

    2012-01-01

    The objective of this study was to investigate if feeding genetically modified (GM) MON810 maize expressing the Bacillus thuringiensis insecticidal protein (Bt maize) had any effects on the porcine intestinal microbiota. Eighteen pigs were weaned at ∼28 days and, following a 6-day acclimatization period, were assigned to diets containing either GM (Bt MON810) maize or non-GM isogenic parent line maize for 31 days (n = 9/treatment). Effects on the porcine intestinal microbiota were assessed through culture-dependent and -independent approaches. Fecal, cecal, and ileal counts of total anaerobes, Enterobacteriaceae, and Lactobacillus were not significantly different between pigs fed the isogenic or Bt maize-based diets. Furthermore, high-throughput 16S rRNA gene sequencing revealed few differences in the compositions of the cecal microbiotas. The only differences were that pigs fed the Bt maize diet had higher cecal abundance of Enterococcaceae (0.06 versus 0%; P < 0.05), Erysipelotrichaceae (1.28 versus 1.17%; P < 0.05), and Bifidobacterium (0.04 versus 0%; P < 0.05) and lower abundance of Blautia (0.23 versus 0.40%; P < 0.05) than pigs fed the isogenic maize diet. A lower enzyme-resistant starch content in the Bt maize, which is most likely a result of normal variation and not due to the genetic modification, may account for some of the differences observed within the cecal microbiotas. These results indicate that Bt maize is well tolerated by the porcine intestinal microbiota and provide additional data for safety assessment of Bt maize. Furthermore, these data can potentially be extrapolated to humans, considering the suitability of pigs as a human model. PMID:22467509

  10. [Predicting the impact of climate change in the next 40 years on the yield of maize in China].

    PubMed

    Ma, Yu-ping; Sun, Lin-li; E, You-hao; Wu, Wei

    2015-01-01

    Climate change will significantly affect agricultural production in China. The combination of the integral regression model and the latest climate projection may well assess the impact of future climate change on crop yield. In this paper, the correlation model of maize yield and meteorological factors was firstly established for different provinces in China by using the integral regression method, then the impact of climate change in the next 40 years on China's maize production was evaluated combined the latest climate prediction with the reason be ing analyzed. The results showed that if the current speeds of maize variety improvement and science and technology development were constant, maize yield in China would be mainly in an increasing trend of reduction with time in the next 40 years in a range generally within 5%. Under A2 climate change scenario, the region with the most reduction of maize yield would be the Northeast except during 2021-2030, and the reduction would be generally in the range of 2.3%-4.2%. Maize yield reduction would be also high in the Northwest, Southwest and middle and lower reaches of Yangtze River after 2031. Under B2 scenario, the reduction of 5.3% in the Northeast in 2031-2040 would be the greatest across all regions. Other regions with considerable maize yield reduction would be mainly in the Northwest and the Southwest. Reduction in maize yield in North China would be small, generally within 2%, under any scenarios, and that in South China would be almost unchanged. The reduction of maize yield in most regions would be greater under A2 scenario than under B2 scenario except for the period of 2021-2030. The effect of the ten day precipitation on maize yield in northern China would be almost positive. However, the effect of ten day average temperature on yield of maize in all regions would be generally negative. The main reason of maize yield reduction was temperature increase in most provinces but precipitation decrease in a few

  11. [Predicting the impact of climate change in the next 40 years on the yield of maize in China].

    PubMed

    Ma, Yu-ping; Sun, Lin-li; E, You-hao; Wu, Wei

    2015-01-01

    Climate change will significantly affect agricultural production in China. The combination of the integral regression model and the latest climate projection may well assess the impact of future climate change on crop yield. In this paper, the correlation model of maize yield and meteorological factors was firstly established for different provinces in China by using the integral regression method, then the impact of climate change in the next 40 years on China's maize production was evaluated combined the latest climate prediction with the reason be ing analyzed. The results showed that if the current speeds of maize variety improvement and science and technology development were constant, maize yield in China would be mainly in an increasing trend of reduction with time in the next 40 years in a range generally within 5%. Under A2 climate change scenario, the region with the most reduction of maize yield would be the Northeast except during 2021-2030, and the reduction would be generally in the range of 2.3%-4.2%. Maize yield reduction would be also high in the Northwest, Southwest and middle and lower reaches of Yangtze River after 2031. Under B2 scenario, the reduction of 5.3% in the Northeast in 2031-2040 would be the greatest across all regions. Other regions with considerable maize yield reduction would be mainly in the Northwest and the Southwest. Reduction in maize yield in North China would be small, generally within 2%, under any scenarios, and that in South China would be almost unchanged. The reduction of maize yield in most regions would be greater under A2 scenario than under B2 scenario except for the period of 2021-2030. The effect of the ten day precipitation on maize yield in northern China would be almost positive. However, the effect of ten day average temperature on yield of maize in all regions would be generally negative. The main reason of maize yield reduction was temperature increase in most provinces but precipitation decrease in a few

  12. Magnitude differences in agronomic, chemical, nutritional, and structural features among different varieties of forage corn grown on dry land and irrigated land.

    PubMed

    Xin, Hangshu; Abeysekara, Samen; Zhang, Xuewei; Yu, Peiqiang

    2015-03-11

    In this study, eight varieties of corn forage grown in semiarid western Canada (including Pioneer P2501, Pioneer P39m26, Pioneer P7443, Hyland HL3085, Hyland HLBaxxos, Hyland HLR219, Hyland HLSR22, and Pickseed Silex BT) were selected to explore the effect of irrigation implementation in comparison with nonirrigation on (1) agronomic characteristics, (2) basic chemical profiles explored by using a near-infrared reflectance (NIR) system, and (3) protein and carbohydrate internal structural parameters revealed by using an attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) system. Also, principal component analysis (PCA) was performed on spectroscopic data for clarification of differences in molecular structural makeup among the varieties. The results showed that irrigation treatment significantly increased (P < 0.05) contents of dry matter (DM) and organic matter (OM) but decreased crude protein (CP) of corn forages. Significant interactions of irrigation treatment and corn variety were observed on most agronomic characteristics (DM yield, T/ha, days to tasseling, days to silking) and crude fiber (CF) and ether extract (EE) contents as well as some spectral data such as cellulosic compounds (CELC) peak intensity, peak ratios of CHO third peak to CELC, α-helix to β-sheet, and CHO third peak to amide I. Additionally, the spectral ratios of chemical functional groups that related to structural and nonstructural carbohydrates and protein polymers in forages did not remain constant over corn varieties cultivated with and without water treatment. Moreover, different cultivars had different growth, structure, and nutrition performances in this study. Although significant differences could be found in peak intensities, PCA results indicated some structural similarities existed between two treated corn forages with the exception of HL3085 and HLBaxxos. In conclusion, irrigation and corn variety had interaction effects on agronomic, chemical

  13. The electrical network of maize root apex is gravity dependent.

    PubMed

    Masi, Elisa; Ciszak, Marzena; Comparini, Diego; Monetti, Emanuela; Pandolfi, Camilla; Azzarello, Elisa; Mugnai, Sergio; Baluška, Frantisek; Mancuso, Stefano

    2015-01-15

    Investigations carried out on maize roots under microgravity and hypergravity revealed that gravity conditions have strong effects on the network of plant electrical activity. Both the duration of action potentials (APs) and their propagation velocities were significantly affected by gravity. Similarly to what was reported for animals, increased gravity forces speed-up APs and enhance synchronized electrical events also in plants. The root apex transition zone emerges as the most active, as well as the most sensitive, root region in this respect.

  14. Predicting maize yield in Zimbabwe using dry dekads derived from remotely sensed Vegetation Condition Index

    NASA Astrophysics Data System (ADS)

    Kuri, Farai; Murwira, Amon; Murwira, Karin S.; Masocha, Mhosisi

    2014-12-01

    Maize is a key crop contributing to food security in Southern Africa yet accurate estimates of maize yield prior to harvesting are scarce. Timely and accurate estimates of maize production are essential for ensuring food security by enabling actionable mitigation strategies and policies for prevention of food shortages. In this study, we regressed the number of dry dekads derived from VCI against official ground-based maize yield estimates to generate simple linear regression models for predicting maize yield throughout Zimbabwe over four seasons (2009-10, 2010-11, 2011-12, and 2012-13). The VCI was computed using Normalized Difference Vegetation Index (NDVI) time series dataset from the SPOT VEGETATION sensor for the period 1998-2013. A significant negative linear relationship between number of dry dekads and maize yield was observed in each season. The variation in yield explained by the models ranged from 75% to 90%. The models were evaluated with official ground-based yield data that was not used to generate the models. There is a close match between the predicted yield and the official yield statistics with an error of 33%. The observed consistency in the negative relationship between number of dry dekads and ground-based estimates of maize yield as well as the high explanatory power of the regression models suggest that VCI-derived dry dekads could be used to predict maize yield before the end of the season thereby making it possible to plan strategies for dealing with food deficits or surpluses on time.

  15. [Plant transpiration in a maize/soybean intercropping system measured with heat balance method].

    PubMed

    Gao, Yang; Duan, Ai-wang; Qiu, Xin-qiang; Zhang, Jun-peng; Sun, Jing-sheng; Wang, He-zhou

    2010-05-01

    In an experimental field with maize/soybean strip intercropping, the transpiration of maize and soybean plants was measured with sap flow gauge based on heat balance method. In the intercropping system, the diurnal change of the sap flow rates of the plants fitted single-peak curve in sunny day and multi-peak curve in cloudy day. The plant sap flow rates were affected by many environmental factors, among which, solar radiation was the most important meteorological factor. The daily sap flow per maize or soybean plant showed significant correlations with solar radiation, air temperature, relative humidity, wind speed, and soil heat flux. During the observation period (June 1-30, 2008), the mean daily transpiration of maize plant (1.44 mm x d(-1)) was about 1.8 times of that of soybean plant (0.79 mm x d(-1)). Maize transpiration and soybean transpiration contributed 64% and 36% to the total transpiration of the intercropping system, respectively. Due to the spatial variation of stem diameter and leaf area, it would be necessary to install more sap flow gauges to accurately measure the sap flow of maize and soybean plants.

  16. Consumer acceptability of stiff porridge based on various composite flour proportions of sorghum, maize and cassava.

    PubMed

    Bangu, N T; Mtebe, K; Nzallawahe, T S

    1994-12-01

    A study was conducted to determine consumer acceptable proportions of flours in sorghum (var. serena) and maize or sorghum, maize and cassava composite flours. Breeder's serena flour extracted at 75 percent was mixed at various proportions with maize or with maize and cassava to constitute composite flours. The various composite flours were made into stiff porridge and presented to a group of panellists for sensory evaluation. The evaluation was conducted by scoring on a hedonic scale of 0-5 for poor to excellent, respectively, for the parameters colour, texture, flavour, taste and overall acceptability. The responses were analysed statistically. Alternatively the panellists were allowed to eat ad-lib any of the presented samples which appealed to them. The results demonstrated that slight incorporation (< 10%) of sorghum (var. serena) to maize flour leads to reduction in consumer acceptability. However, increased incorporation of sorghum in excess of 10 percent leads to no significant decrease in consumer acceptability until a level of 30 percent incorporation is exceeded. In sorghum, maize, cassava composite flours the formulation of 30:40:30, respectively, was found to be most acceptable. It is suggested that at this combination of flours desirable textural characteristics of the porridge overrides other factors in contributing to its acceptability.

  17. Divergence between sympatric rice- and maize-infecting populations of Rhizoctonia solani AG-1 IA from Latin America.

    PubMed

    González-Vera, A D; Bernardes-de-Assis, J; Zala, M; McDonald, B A; Correa-Victoria, F; Graterol-Matute, E J; Ceresini, P C

    2010-02-01

    ABSTRACT The basidiomycetous fungus Rhizoctonia solani anastomosis group (AG)-1 IA is a major pathogen in Latin America causing sheath blight (SB) of rice. Particularly in Venezuela, the fungus also causes banded leaf and sheath blight (BLSB) on maize, which is considered an emerging disease problem where maize replaced traditional rice-cropping areas or is now planted in adjacent fields. Our goals in this study were to elucidate (i) the effects of host specialization on gene flow between sympatric and allopatric rice and maize-infecting fungal populations and (ii) the reproductive mode of the fungus, looking for evidence of recombination. In total, 375 isolates of R. solani AG1 IA sampled from three sympatric rice and maize fields in Venezuela (Portuguesa State) and two allopatric rice fields from Colombia (Meta State) and Panama (Chiriquí State) were genotyped using 10 microsatellite loci. Allopatric populations from Venezuela, Colombia, and Panama were significantly differentiated (Phi(ST) of 0.16 to 0.34). Partitioning of the genetic diversity indicated differentiation between sympatric populations from different host species, with 17% of the total genetic variation distributed between hosts while only 3 to 6% was distributed geographically among the sympatric Venezuelan fields. We detected symmetrical historical migration between the rice- and the maize-infecting populations from Venezuela. Rice- and maize-derived isolates were able to infect both rice and maize but were more aggressive on their original hosts, consistent with host specialization. Because the maize- and rice-infecting populations are still cross-pathogenic, we postulate that the genetic differentiation was relatively recent and mediated via a host shift. An isolation with migration analysis indicated that the maize-infecting population diverged from the rice-infecting population between 40 and 240 years ago. Our findings also suggest that maize-infecting populations have a mainly recombining

  18. Registration of maize inbred line 'GT888'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) inbred line GT888 (PI 670116) was developed and released by the USDA-ARS in cooperation with the University of Georgia, and in participation with the USDA Germplasm Enhancement of Maize (GEM) project. GT888 was derived from GEM population DK888:N11 (GEMN-0177), which has 50% tro...

  19. A meteorologically driven maize stress indicator model

    NASA Technical Reports Server (NTRS)

    Taylor, T. W.; Ravet, F. W. (Principal Investigator)

    1981-01-01

    A maize soil moisture and temperature stress model is described which was developed to serve as a meteorological data filter to alert commodity analysts to potential stress conditions in the major maize-producing areas of the world. The model also identifies optimum climatic conditions and planting/harvest problems associated with poor tractability.

  20. Use of tropical maize for bioethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical maize is an alternative energy crop being considered as a feedstock for bioethanol production in the North Central and Midwest United States. Tropical maize is advantageous because it produces large amounts of soluble sugars in its stalks, creates a large amount of biomass, and requires lo...

  1. The genetic architecture of maize height

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state (IBS) among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formida...

  2. Maize metabolic network construction and transcriptome analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A framework for understanding the synthesis and catalysis of metabolites and other biochemicals by proteins is crucial for unraveling the physiology of cells. To create such a framework for Zea mays ssp. mays (maize), we developed MaizeCyc a metabolic network of enzyme catalysts, proteins, carbohydr...

  3. Comparative genomics of Arabidopsis and maize: prospects and limitations

    PubMed Central

    Brendel, Volker; Kurtz, Stefan; Walbot, Virginia

    2002-01-01

    The completed Arabidopsis genome seems to be of limited value as a model for maize genomics. In addition to the expansion of repetitive sequences in maize and the lack of genomic micro-colinearity, maize-specific or highly-diverged proteins contribute to a predicted maize proteome of about 50,000 proteins, twice the size of that of Arabidopsis. PMID:11897028

  4. Aggressiveness of Cephalosporium maydis causing late wilt of maize in Spain.

    PubMed

    García-Carneros, A B; Girón, I; Molinero-Ruiz, L

    2012-01-01

    Late wilt of maize, caused by the vascular and soilborne pathogen Cephalosporium maydis, was identified in the Iberian Peninsula in 2008. During the last years the incidence and economical impact of the disease has importantly increased both in Portugal and Spain. Varieties of maize displaying tolerance to the pathogen are available, but the effectiveness can be dependent on the virulence of the fungus (i.e. ability to cause disease on a specific genotype). On the other hand, strains of crop pathogens from different geographic origins can differ with regard to the degree of disease caused on a specific genotype (i.e. aggressiveness). Our working hypothesis was that isolates of C. maydis from different maize growing areas may differ in aggressiveness towards maize plants. Seven fungal strains were isolated in 2009 from diseased plants collected in the most important maize growing regions of Spain and used to inoculate two susceptible maize varieties grown in shadehouse from March to July 2010. The experimental unit consisted of two 4-day-old seedlings planted in an 8-liter pot filled with sand/silt previously infested with 200 g of wheat grains colonized by the fungi. Non colonized wheat grains were used for the control treatments. Six replications (pots) were established for each variety/isolate combination according to a complete randomized 2 x 8 factorial design. The percentage of necrotic and dry aboveground tissues was recorded 14 weeks after inoculation and thereafter weekly until physiological senescence of the control plants. At the end of the experiment, weights of roots and aboveground parts of the plants were recorded. Initial occurrence of symptoms in the plants was significantly dependent on the isolate of C. maydis and on the maize variety. However, final severity of aboveground symptoms (leaf necroses and drying up) was only dependent on the fungal isolate. All the isolates significantly reduced the root weight of both varieties of maize. The highest

  5. Targeted Sequencing Reveals Large-Scale Sequence Polymorphism in Maize Candidate Genes for Biomass Production and Composition

    PubMed Central

    Ulpinnis, Chris; Scholz, Uwe; Altmann, Thomas

    2015-01-01

    A major goal of maize genomic research is to identify sequence polymorphisms responsible for phenotypic variation in traits of economic importance. Large-scale detection of sequence variation is critical for linking genes, or genomic regions, to phenotypes. However, due to its size and complexity, it remains expensive to generate whole genome sequences of sufficient coverage for divergent maize lines, even with access to next generation sequencing (NGS) technology. Because methods involving reduction of genome complexity, such as genotyping-by-sequencing (GBS), assess only a limited fraction of sequence variation, targeted sequencing of selected genomic loci offers an attractive alternative. We therefore designed a sequence capture assay to target 29 Mb genomic regions and surveyed a total of 4,648 genes possibly affecting biomass production in 21 diverse inbred maize lines (7 flints, 14 dents). Captured and enriched genomic DNA was sequenced using the 454 NGS platform to 19.6-fold average depth coverage, and a broad evaluation of read alignment and variant calling methods was performed to select optimal procedures for variant discovery. Sequence alignment with the B73 reference and de novo assembly identified 383,145 putative single nucleotide polymorphisms (SNPs), of which 42,685 were non-synonymous alterations and 7,139 caused frameshifts. Presence/absence variation (PAV) of genes was also detected. We found that substantial sequence variation exists among genomic regions targeted in this study, which was particularly evident within coding regions. This diversification has the potential to broaden functional diversity and generate phenotypic variation that may lead to new adaptations and the modification of important agronomic traits. Further, annotated SNPs identified here will serve as useful genetic tools and as candidates in searches for phenotype-altering DNA variation. In summary, we demonstrated that sequencing of captured DNA is a powerful approach for

  6. Antioxidant, α-glucosidase and xanthine oxidase inhibitory activity of bioactive compounds from maize (Zea mays L.).

    PubMed

    Nile, Shivraj H; Park, Se W

    2014-01-01

    Chemical investigations into maize (Zea mays L.) kernels yielded phenolic compounds, which were structurally established using chromatographic and spectroscopic methods. The isolated phenolic compounds from maize kernel were examined in vitro for their antioxidant abilities by DPPH (2,2-diphenyl-1-picryl hydrazine) radical, OH radical scavenging activity, and reducing ability, along with α-glucosidase and xanthine oxidase (XO) inhibition. The isolated maize phenolics revealed significant xanthine oxidase and α-glucosidase inhibitory activity to that of allopurinol and acarbose in vitro and in vivo, respectively. The kinetics study with xanthine oxidase revealed competitive type of inhibition by isolated maize vanillic acid (M2), ferulic acid (M5), 3'-methoxyhirsutrin (M7), and peonidin-3-glucoside (M10) as compared to control allopurinol. Overall, with few exceptions, all the phenolic compounds from maize kernel revealed significant biological activities with all parameters examined. Also, the phenolic compounds from maize were found to be more reactive toward DPPH radical and had considerable reducing ability and OH radical scavenging activity. These findings suggest that maize kernel phenolic compounds can be considered as potential antioxidant, α-glucosidase, and XO inhibitory agents those might be further explored for the design of lead antioxidant, antidiabetic and antigout drug candidates using in vivo trials. PMID:23957301

  7. Mycorrhiza and PGPB modulate maize biomass, nutrient uptake and metabolic pathways in maize grown in mining-impacted soil.

    PubMed

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2015-12-01

    Abiotic stress factors including poor nutrient content and heavy metal contamination in soil, can limit plant growth and productivity. The main goal of our study was to evaluate element uptake, biomass and metabolic responses in maize roots growing in mining-impacted soil with the combination of arbuscular mycorrhiza (My) and plant growth promoting bacteria (PGPB/B). Maize plants subjected to PGPB, My and combined treatments showed a significant increase in biomass and uptake of some elements in shoot and root. Metabolite analysis identified 110 compounds that were affected ≥2-fold compared to control, with 69 metabolites upregulated in the My group, 53 metabolites in the My+B group and 47 metabolites in B group. Pathway analysis showed that impact on glyoxylate and dicarboxylate metabolism was common between My and My+B groups, whereas PGPB group showed a unique effect on fatty acid biosynthesis with significant increase in palmitic acid and stearic acid. Differential regulation of some metabolites by mycorrhizal treatment correlated with root biomass while PGPB regulated metabolites correlated with biomass increase in shoot. Overall, the combination of rhizospheric microorganisms used in our study significantly increased maize nutrient uptake and growth relative to control. The changes in metabolic pathways identified during the symbiotic interaction will improve our understanding of mechanisms involved in rhizospheric interactions that are responsible for increased growth and nutrient uptake in crop plants.

  8. Aflatoxins and ochratoxin A in maize of Punjab, Pakistan.

    PubMed

    Iram, Wajiha; Anjum, Tehmina; Abbas, Mateen; Khan, Abdul Muqeet

    2014-01-01

    Aflatoxin and ochratoxin levels were determined in maize samples collected from store houses of 15 districts belonging to three agro-ecological zones of Punjab, Pakistan. Toxins were extracted by Aflaochra immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC). Mean moisture content of maize kernels was recorded above the safe storage level of 15%. Results indicated that aflatoxin B1 and B2 contamination was found in 97.3% and 78.9% of the collected samples, respectively. Aflatoxin G1, aflatoxin G2 and ochratoxin A were not detected in any sample. Among positive samples, 77.3% contained aflatoxin B1 and 28% aflatoxin B2, exceeding the legal limits as set by the European Union (EU) and the United States Food and Drug Administration (USFDA). It was concluded that a significant number of samples contained aflatoxin B1 and B2 above the legal limits.

  9. Using observed warming to identify hazards to Mozambique maize production

    USGS Publications Warehouse

    Funk, Christopher C.; Harrison, Laura; Eilerts, Gary

    2011-01-01

    New Perspectives on Crop Yield Constraints because of Climate Change. Climate change impact assessments usually focus on changes to precipitation because most global food production is from rainfed cropping systems; however, other aspects of climate change may affect crop growth and potential yields.A recent (2011) study by the University of California, Santa Barbara (UCSB) Climate Hazards Group, determined that climate change may be affecting Mozambique's primary food crop in a usually overlooked, but potentially significant way (Harrison and others, 2011). The study focused on the direct relation between maize crop development and growing season temperature. It determined that warming during the past three decades in Mozambique may be causing more frequent crop stress and yield reductions in that country's maize crop, independent of any changes occurring in rainfall. This report summarizes the findings and conclusions of that study.

  10. Stability of the MON 810 transgene in maize.

    PubMed

    La Paz, Jose Luis; Pla, Maria; Papazova, Nina; Puigdomènech, Pere; Vicient, Carlos M

    2010-12-01

    We analysed the DNA variability of the transgene insert and its flanking regions in maize MON 810 commercial varieties. Southern analysis demonstrates that breeding, since the initial transformation event more than 10 years ago, has not resulted in any rearrangements. A detailed analysis on the DNA variability at the nucleotide level, using DNA mismatch endonuclease assays, showed the lack of polymorphisms in the transgene insert. We conclude that the mutation rate of the transgene is not significantly different from that observed in the maize endogenous genes. Six SNPs were observed in the 5'flanking region, corresponding to a Zeon1 retrotransposon long terminal repeat. All six SNPs are more than 500 bp upstream of the point of insertion of the transgene and do not affect the reliability of the established PCR-based transgene detection and quantification methods. The mutation rate of the flanking region is similar to that expected for a maize repetitive sequence. We detected low levels of cytosine methylation in leaves of different transgenic varieties, with no significant differences on comparing different transgenic varieties, and minor differences in cytosine methylation when comparing leaves at different developmental stages. There was also a reduction in cryIAb mRNA accumulation during leaf development. PMID:20936423

  11. Association Mapping for Important Agronomic Traits in Core Collection of Rice (Oryza sativa L.) with SSR Markers

    PubMed Central

    Zhang, Peng; Liu, Xiangdong; Tong, Hanhua; Lu, Yonggen; Li, Jinquan

    2014-01-01

    Mining elite genes within rice landraces is of importance for the improvement of cultivated rice. An association mapping for 12 agronomic traits was carried out using a core collection of rice consisting of 150 landraces (Panel 1) with 274 simple sequence repeat (SSR) markers, and the mapping results were further verified using a Chinese national rice micro-core collection (Panel 2) and a collection from a global molecular breeding program (Panel 3). Our results showed that (1) 76 significant (P<0.05) trait-marker associations were detected using mixed linear model (MLM) within Panel 1 in two years, among which 32% were identical with previously mapped QTLs, and 11 significant associations had >10% explained ratio of genetic variation; (2) A total of seven aforementioned trait-marker associations were verified within Panel 2 and 3 when using a general linear model (GLM) and 55 SSR markers of the 76 significant trait-marker associations. However, no significant trait-marker association was found to be identical within three panels when using the MLM model; (3) several desirable alleles of the loci which showed significant trait-marker associations were identified. The research provided important information for further mining these elite genes within rice landraces and using them for rice breeding. PMID:25360796

  12. Uptake, translocation, and toxicity of gold nanorods in maize

    NASA Astrophysics Data System (ADS)

    Moradi Shahmansouri, Nastaran

    root and leaf cells. However, the translocation factor of gold nanorods from root to leaf was very low in this experiment. In the second experiment, maize seedlings were exposed to different (lower) concentrations of gold nanorods measured at 4.5x10-3 mg/l, 0.45 mg/l, and 2.25 mg/l for 10 days. Transpiration and biomass measurements demonstrated that the higher concentration of gold nanorods caused lower water uptake and growth, but lower concentrations did not show a significant toxic effect. According to ICP-MS results, root systems of the exposed plants were surrounded by high concentrations of sorbed nanorods, which physically interfered with uptake pathways and, thus, inhibited plant growth and nutritional uptake.

  13. [Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils].

    PubMed

    Wang, Fang; Guo, Weil; Ma, Peng-kun; Pan, Liang; Zhang, Jun

    2016-01-15

    A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Glomus aggregatum (GA) and Funneliformis mosseae (FM) on AM colonization rate, biomass, nutrient uptake, C: N: P stoichiometric and Ce uptake and transport by maize (Zea mays L.) grown in soils with different levels of Ce-contaminated (100, 500 and 1000 mg x kg(-1)). The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7. 12% to 74.47%. The increasing concentration of Ce in soils significantly decreased the mycorrhizal colonization rate, biomass, nutrition contents and transport rate of Ce from root to shoot of maize, and significantly increased C: P and N: P ratios and Ce contents in shoot and root of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C: N: P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soils, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoot and root in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and severe Ce-contaminated soils, and promoted the transport of Ce from root to shoot. The experiment demonstrates that AM fungi can alleviate toxic effects of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements. PMID

  14. [Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils].

    PubMed

    Wang, Fang; Guo, Weil; Ma, Peng-kun; Pan, Liang; Zhang, Jun

    2016-01-15

    A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Glomus aggregatum (GA) and Funneliformis mosseae (FM) on AM colonization rate, biomass, nutrient uptake, C: N: P stoichiometric and Ce uptake and transport by maize (Zea mays L.) grown in soils with different levels of Ce-contaminated (100, 500 and 1000 mg x kg(-1)). The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7. 12% to 74.47%. The increasing concentration of Ce in soils significantly decreased the mycorrhizal colonization rate, biomass, nutrition contents and transport rate of Ce from root to shoot of maize, and significantly increased C: P and N: P ratios and Ce contents in shoot and root of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C: N: P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soils, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoot and root in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and severe Ce-contaminated soils, and promoted the transport of Ce from root to shoot. The experiment demonstrates that AM fungi can alleviate toxic effects of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements.

  15. Gene flow in maize fields with different local pollen densities

    NASA Astrophysics Data System (ADS)

    Goggi, A. Susana; Lopez-Sanchez, Higinio; Caragea, Petrutza; Westgate, Mark; Arritt, Raymond; Clark, Craig A.

    2007-08-01

    The development of maize ( Zea mays L.) varieties as factories of pharmaceutical and industrial compounds has renewed interest in controlling pollen dispersal. The objective of this study was to compare gene flow into maize fields of different local pollen densities under the same environmental conditions. Two fields of approximately 36 ha were planted with a nontransgenic, white hybrid, in Ankeny, Iowa, USA. In the center of both fields, a 1-ha plot of a yellow-seeded stacked RR/Bt transgenic hybrid was planted as a pollen source. Before flowering, the white receiver maize of one field was detasseled in a 4:1 ratio to reduce the local pollen density (RPD). The percentage of outcross in the field with RPD was 42.2%, 6.3%, and 1.3% at 1, 10, and 35 m from the central plot, respectively. The percentage of outcross in the white maize with normal pollen density (NPD) was 30.1%, 2.7%, and 0.4%, respectively, at these distances. At distances greater than 100 m, the outcross frequency decreased below 0.1 and 0.03% in the field with RPD and NPD, respectively. A statistical model was used to compare pollen dispersal based on observed outcross percentages. The likelihood ratio test confirmed that the models of outcrossing in the two fields were significantly different ( P is practically 0). Results indicated that when local pollen is low, the incoming pollen has a competitive advantage and the level of outcross is significantly greater than when the local pollen is abundant.

  16. INTEGRATED WEED CONTROL IN MAIZE.

    PubMed

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

  17. INTEGRATED WEED CONTROL IN MAIZE.

    PubMed

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach. PMID:27145588

  18. Trehalose accumulation in Azospirillum brasilense improves drought tolerance and biomass in maize plants.

    PubMed

    Rodríguez-Salazar, Julieta; Suárez, Ramón; Caballero-Mellado, Jesús; Iturriaga, Gabriel

    2009-07-01

    Bacteria of the genus Azospirillum increase the grain yield of several grass crops. In this work the effect of inoculating maize plants with genetically engineered Azospirillum brasilense for trehalose biosynthesis was determined. Transformed bacteria with a plasmid harboring a trehalose biosynthesis gene-fusion from Saccharomyces cerevisiae were able to grow up to 0.5 M NaCl and to accumulate trehalose, whereas wild-type A. brasilense did not tolerate osmotic stress or accumulate significant levels of the disaccharide. Moreover, 85% of maize plants inoculated with transformed A. brasilense survived drought stress, in contrast with only 55% of plants inoculated with the wild-type strain. A 73% increase in biomass of maize plants inoculated with transformed A. brasilense compared with inoculation with the wild-type strain was found. In addition, there was a significant increase of leaf and root length in maize plants inoculated with transformed A. brasilense. Therefore, inoculation of maize plants with A. brasilense containing higher levels of trehalose confers drought tolerance and a significant increase in leaf and root biomass. This work opens the possibility that A. brasilense modified with a chimeric trehalose biosynthetic gene from yeast could increase the biomass, grain yield and stress tolerance in other relevant crops.

  19. Nutrient absorbtion of weeds in maize.

    PubMed

    Lehoczky, E; Kismányoky, A; Nagy, P; Németh, T

    2008-01-01

    Our study was carried out in Hungary at Keszthely, in 2007. The effect of different cultivation methods: no-till drill, disk tillage, conventional tillage (ploughing) and five increasing N doses were studied on the weediness. The bi-factorial trial was arranged in split plot design with four replications. Crop rotation: winter wheat-winter wheat-maize-maize. The seeding of maize was 23rd of April in 2007. The weed survey was made with Balázs-Ujvárosi coenological method on the 17th of May. In the experiment were found 21 weed species. We collected all plants of every weed species by plots. The sample area was 1 m2. Furthermore five maize plants per plot were sampled on the 22nd of May. Maize was at 3-4 leaves stage. For reason of competition studies no herbicides were applied on sampling sites. The aerial parts of weeds and maize plants were collected, and the fresh and dry matter weight was measured. We analyzed in detail, the occurrence of weed species, and the biomass production of weeds in comparison with maize. The effect of different cultivation methods markedly demonstrated the weed cover, the number of perennial and annual weeds and the number of occurring weed species.

  20. Importance of rare taxa for bacterial diversity in the rhizosphere of Bt- and conventional maize varieties

    PubMed Central

    Dohrmann, Anja B; Küting, Meike; Jünemann, Sebastian; Jaenicke, Sebastian; Schlüter, Andreas; Tebbe, Christoph C

    2013-01-01

    Ribosomal 16S rRNA gene pyrosequencing was used to explore whether the genetically modified (GM) Bt-maize hybrid MON 89034 × MON 88017, expressing three insecticidal recombinant Cry proteins of Bacillus thuringiensis, would alter the rhizosphere bacterial community. Fine roots of field cultivated Bt-maize and three conventional maize varieties were analyzed together with coarse roots of the Bt-maize. A total of 547 000 sequences were obtained. Library coverage was 100% at the phylum and 99.8% at the genus rank. Although cluster analyses based on relative abundances indicated no differences at higher taxonomic ranks, genera abundances pointed to variety specific differences. Genera-based clustering depended solely on the 49 most dominant genera while the remaining 461 rare genera followed a different selection. A total of 91 genera responded significantly to the different root environments. As a benefit of pyrosequencing, 79 responsive genera were identified that might have been overlooked with conventional cloning sequencing approaches owing to their rareness. There was no indication of bacterial alterations in the rhizosphere of the Bt-maize beyond differences found between conventional varieties. B. thuringiensis-like phylotypes were present at low abundance (0.1% of Bacteria) suggesting possible occurrence of natural Cry proteins in the rhizospheres. Although some genera indicated potential phytopathogenic bacteria in the rhizosphere, their abundances were not significantly different between conventional varieties and Bt-maize. With an unprecedented sensitivity this study indicates that the rhizosphere bacterial community of a GM maize did not respond abnormally to the presence of three insecticidal proteins in the root tissue. PMID:22791236

  1. [Effects of herb residue vermicompost on maize growth and soil fertility].

    PubMed

    Li, Jing-Juan; Zhou, Bo; Zhang, Chi; Zhang, Jing; Xu, Huan; Yang, Xiao-Xue; Chen, Xu-Fei; Dai, Jun

    2013-09-01

    A pot experiment was conducted to evaluate the effects of herb residue vermicompost on maize growth and soil fertility. With the increasing application rate of vermicompost, the plant height, stem diameter, leaf area, and chlorophyll content of maize all increased significantly. After 60 days growth of maize, the soil bulk density in most vermicompost treatments decreased significantly. The soil pH in vermicompost treatments was significantly higher than that in CK and in chemical fertilization treatments. In addition, the soil total nitrogen and organic matter contents in vermicompost treatments were obviously higher than those in chemical fertilization treatments. It was suggested that herb residue vermicompost could be used as an efficient and high-quality organic fertilizer, and its appropriate application could improve soil physical structure, alleviate soil acidification, increase soil organic matter and nitrogen contents, and promote crop growth. PMID:24417126

  2. [Effects of herb residue vermicompost on maize growth and soil fertility].

    PubMed

    Li, Jing-Juan; Zhou, Bo; Zhang, Chi; Zhang, Jing; Xu, Huan; Yang, Xiao-Xue; Chen, Xu-Fei; Dai, Jun

    2013-09-01

    A pot experiment was conducted to evaluate the effects of herb residue vermicompost on maize growth and soil fertility. With the increasing application rate of vermicompost, the plant height, stem diameter, leaf area, and chlorophyll content of maize all increased significantly. After 60 days growth of maize, the soil bulk density in most vermicompost treatments decreased significantly. The soil pH in vermicompost treatments was significantly higher than that in CK and in chemical fertilization treatments. In addition, the soil total nitrogen and organic matter contents in vermicompost treatments were obviously higher than those in chemical fertilization treatments. It was suggested that herb residue vermicompost could be used as an efficient and high-quality organic fertilizer, and its appropriate application could improve soil physical structure, alleviate soil acidification, increase soil organic matter and nitrogen contents, and promote crop growth.

  3. Effect of MIR604 transgenic maize at different stages of development on western corn rootworm (Coleoptera: Chrysomelidae) in a central Missouri field environment.

    PubMed

    Frank, Daniel L; Bukowsky, Rebecca; French, B Wade; Hibbard, Bruce E

    2011-12-01

    The establishment and survival of western corn rootworm, Diabrotica virgifera virgifera LeConte, was evaluated on transgenic Bacillus thuringiensis Berliner maize, Zea mays L., expressing the mCry3A protein (MIR604) and non-Bt maize with the same genetic background (isoline maize) at different stages of development in 2007 and 2008. Overall, western corn rootworm larval recovery, root damage, and adult emergence were significantly higher on isoline maize compared with MIR604. The number of larvae and adults collected from MIR604 did not significantly differ among egg hatch dates from each maize developmental stage evaluated in either year. In 2007, damage to isoline maize roots was lower than expected and never exceeded 0.24 nodes of damage. In 2008, over 0.60 nodes of damage occurred on isoline maize roots. The mean weight and head capsule width of larvae and adults recovered from MIR604 and isoline maize were generally not significantly different. Results are discussed in relation to insect resistance management of western corn rootworm.

  4. Constitutive expression of the maize genes B1 and C1 in transgenic Hi II maize results in differential tissue pigmentation and generates resistance to Helicoverpa zea.

    PubMed

    Johnson, Eric T; Berhow, Mark A; Dowd, Patrick F

    2010-02-24

    Anthocyanin biosynthesis in maize protects tissues from biotic and abiotic stresses. Constitutive expression of the maize B1 and C1 genes, which induces anthocyanin biosynthesis, resulted in transgenic plants with varied phenotypes. Some colored leaves were substantially resistant to thrips damage, while only leaves with the highest levels of cyanidin, the predominant anthocyanidin detected in all colored transgenic tissues, were resistant to corn earworm (CEW) larvae. Colored anthers were resistant to CEW feeding, and reductions in CEW growth were significantly correlated to levels of cyanidin in the anthers. Cyanidin chloride and cyanidin-3-glucoside chloride added to insect diet slowed the growth of CEW larvae. Attempts to produce 3'5'-hydroxylated anthocyanins in colored maize with the expression of a petunia F3'5'H hydroxylase gene were unsuccessful. PMID:20108901

  5. Association analysis of single nucleotide polymorphisms in candidate genes with root traits in maize (Zea mays L.) seedlings.

    PubMed

    Kumar, Bharath; Abdel-Ghani, Adel H; Pace, Jordon; Reyes-Matamoros, Jenaro; Hochholdinger, Frank; Lübberstedt, Thomas

    2014-07-01

    Several genes involved in maize root development have been isolated. Identification of SNPs associated with root traits would enable the selection of maize lines with better root architecture that might help to improve N uptake, and consequently plant growth particularly under N deficient conditions. In the present study, an association study (AS) panel consisting of 74 maize inbred lines was screened for seedling root traits in 6, 10, and 14-day-old seedlings. Allele re-sequencing of candidate root genes Rtcl, Rth3, Rum1, and Rul1 was also carried out in the same AS panel lines. All four candidate genes displayed different levels of nucleotide diversity, haplotype diversity and linkage disequilibrium. Gene based association analyses were carried out between individual polymorphisms in candidate genes, and root traits measured in 6, 10, and 14-day-old maize seedlings. Association analyses revealed several polymorphisms within the Rtcl, Rth3, Rum1, and Rul1 genes associated with seedling root traits. Several nucleotide polymorphisms in Rtcl, Rth3, Rum1, and Rul1 were significantly (P<0.05) associated with seedling root traits in maize suggesting that all four tested genes are involved in the maize root development. Thus considerable allelic variation present in these root genes can be exploited for improving maize root characteristics.

  6. Unmanned Aerial Vehicles for High-Throughput Phenotyping and Agronomic Research.

    PubMed

    Shi, Yeyin; Thomasson, J Alex; Murray, Seth C; Pugh, N Ace; Rooney, William L; Shafian, Sanaz; Rajan, Nithya; Rouze, Gregory; Morgan, Cristine L S; Neely, Haly L; Rana, Aman; Bagavathiannan, Muthu V; Henrickson, James; Bowden, Ezekiel; Valasek, John; Olsenholler, Jeff; Bishop, Michael P; Sheridan, Ryan; Putman, Eric B; Popescu, Sorin; Burks, Travis; Cope, Dale; Ibrahim, Amir; McCutchen, Billy F; Baltensperger, David D; Avant, Robert V; Vidrine, Misty; Yang, Chenghai

    2016-01-01

    Advances in automation and data science have led agriculturists to seek real-time, high-quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs) have recently gained traction as agricultural data collection systems. Using UAVs for agricultural remote sensing is an innovative technology that differs from traditional remote sensing in more ways than strictly higher-resolution images; it provides many new and unique possibilities, as well as new and unique challenges. Herein we report on processes and lessons learned from year 1-the summer 2015 and winter 2016 growing seasons-of a large multidisciplinary project evaluating UAV images across a range of breeding and agronomic research trials on a large research farm. Included are team and project planning, UAV and sensor selection and integration, and data collection and analysis workflow. The study involved many crops and both breeding plots and agronomic fields. The project's goal was to develop methods for UAVs to collect high-quality, high-volume crop data with fast turnaround time to field scientists. The project included five teams: Administration, Flight Operations, Sensors, Data Management, and Field Research. Four case studies involving multiple crops in breeding and agronomic applications add practical descriptive detail. Lessons learned include critical information on sensors, air vehicles, and configuration parameters for both. As the first and

  7. Unmanned Aerial Vehicles for High-Throughput Phenotyping and Agronomic Research.

    PubMed

    Shi, Yeyin; Thomasson, J Alex; Murray, Seth C; Pugh, N Ace; Rooney, William L; Shafian, Sanaz; Rajan, Nithya; Rouze, Gregory; Morgan, Cristine L S; Neely, Haly L; Rana, Aman; Bagavathiannan, Muthu V; Henrickson, James; Bowden, Ezekiel; Valasek, John; Olsenholler, Jeff; Bishop, Michael P; Sheridan, Ryan; Putman, Eric B; Popescu, Sorin; Burks, Travis; Cope, Dale; Ibrahim, Amir; McCutchen, Billy F; Baltensperger, David D; Avant, Robert V; Vidrine, Misty; Yang, Chenghai

    2016-01-01

    Advances in automation and data science have led agriculturists to seek real-time, high-quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs) have recently gained traction as agricultural data collection systems. Using UAVs for agricultural remote sensing is an innovative technology that differs from traditional remote sensing in more ways than strictly higher-resolution images; it provides many new and unique possibilities, as well as new and unique challenges. Herein we report on processes and lessons learned from year 1-the summer 2015 and winter 2016 growing seasons-of a large multidisciplinary project evaluating UAV images across a range of breeding and agronomic research trials on a large research farm. Included are team and project planning, UAV and sensor selection and integration, and data collection and analysis workflow. The study involved many crops and both breeding plots and agronomic fields. The project's goal was to develop methods for UAVs to collect high-quality, high-volume crop data with fast turnaround time to field scientists. The project included five teams: Administration, Flight Operations, Sensors, Data Management, and Field Research. Four case studies involving multiple crops in breeding and agronomic applications add practical descriptive detail. Lessons learned include critical information on sensors, air vehicles, and configuration parameters for both. As the first and

  8. Unmanned Aerial Vehicles for High-Throughput Phenotyping and Agronomic Research

    PubMed Central

    Shi, Yeyin; Thomasson, J. Alex; Murray, Seth C.; Pugh, N. Ace; Rooney, William L.; Shafian, Sanaz; Rajan, Nithya; Rouze, Gregory; Morgan, Cristine L. S.; Neely, Haly L.; Rana, Aman; Bagavathiannan, Muthu V.; Henrickson, James; Bowden, Ezekiel; Valasek, John; Olsenholler, Jeff; Bishop, Michael P.; Sheridan, Ryan; Putman, Eric B.; Popescu, Sorin; Burks, Travis; Cope, Dale; Ibrahim, Amir; McCutchen, Billy F.; Baltensperger, David D.; Avant, Robert V.; Vidrine, Misty; Yang, Chenghai

    2016-01-01

    Advances in automation and data science have led agriculturists to seek real-time, high-quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs) have recently gained traction as agricultural data collection systems. Using UAVs for agricultural remote sensing is an innovative technology that differs from traditional remote sensing in more ways than strictly higher-resolution images; it provides many new and unique possibilities, as well as new and unique challenges. Herein we report on processes and lessons learned from year 1—the summer 2015 and winter 2016 growing seasons–of a large multidisciplinary project evaluating UAV images across a range of breeding and agronomic research trials on a large research farm. Included are team and project planning, UAV and sensor selection and integration, and data collection and analysis workflow. The study involved many crops and both breeding plots and agronomic fields. The project’s goal was to develop methods for UAVs to collect high-quality, high-volume crop data with fast turnaround time to field scientists. The project included five teams: Administration, Flight Operations, Sensors, Data Management, and Field Research. Four case studies involving multiple crops in breeding and agronomic applications add practical descriptive detail. Lessons learned include critical information on sensors, air vehicles, and configuration parameters for both. As the first

  9. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

    NASA Astrophysics Data System (ADS)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

    2016-04-01

    Maize is the most important C4 crop worldwide. It is also the second most important crop worldwide (C3 and C4 mixed), and is a dominant crop in some world regions. Therefore, it can potentially influence local climate and air quality through its exchanges of gases with the atmosphere. Among others, biogenic volatile organic compounds (BVOC) are known to influence the atmospheric composition and thereby modify greenhouse gases lifetime and pollutant formation in the atmosphere. However, so far, only two studies have dealt with BVOC exchanges from maize. Moreover, these studies were conducted on a limited range of meteorological and phenological conditions, so that the knowledge of BVOC exchanges by this crop remains poor. Here, we present the first BVOC measurement campaign performed at ecosystem-scale on a maize field during a whole growing season. It was carried out in the Lonzée Terrestrial Observatory (LTO), an ICOS site. BVOC fluxes were measured by the disjunct by mass-scanning eddy covariance technique with a proton transfer reaction mass spectrometer for BVOC mixing ratios measurements. Outstanding results are (i) BVOC exchanges from soil were as important as BVOC exchanges from maize itself; (ii) BVOC exchanges observed on our site were much lower than exchanges observed by other maize studies, even under normalized temperature and light conditions, (iii) they were also lower than those observed on other crops grown in Europe. Lastly (iv), BVOC exchanges observed on our site under standard environmental conditions, i.e., standard emission factors SEF, were much lower than those currently considered by BVOC exchange up-scaling models. From those observations, we deduced that (i) soil BVOC exchanges should be better understood and should be incorporated in terrestrial BVOC exchanges models, and that (ii) SEF for the C4 crop plant functional type cannot be evaluated at global scale but should be determined for each important agronomic and pedo-climatic region

  10. Quantitative trait locus analysis of multiple agronomic traits in the model legume Lotus japonicus.

    PubMed

    Gondo, Takahiro; Sato, Shusei; Okumura, Kenji; Tabata, Satoshi; Akashi, Ryo; Isobe, Sachiko

    2007-07-01

    The first quantitative trait locus (QTL) analysis of multiple agronomic traits in the model legume Lotus japonicus was performed with a population of recombinant inbred lines derived from Miyakojima MG-20 x Gifu B-129. Thirteen agronomic traits were evaluated in 2004 and 2005: traits of vegetative parts (plant height, stem thickness, leaf length, leaf width, plant regrowth, plant shape, and stem color), flowering traits (flowering time and degree), and pod and seed traits (pod length, pod width, seeds per pod, and seed mass). A total of 40 QTLs were detected that explained 5%-69% of total variation. The QTL that explained the most variation was that for stem color, which was detected in the same region of chromosome 2 in both years. Some QTLs were colocated, especially those for pod and seed traits. Seed mass QTLs were located at 5 locations that mapped to the corresponding genomic positions of equivalent QTLs in soybean, pea, chickpea, and mung bean. This study provides fundamental information for breeding of agronomically important legume crops.

  11. Photophobic behavior of maize roots.

    PubMed

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-07-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed "crawling" behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize.

  12. Photophobic behavior of maize roots

    PubMed Central

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-01-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed “crawling” behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize. PMID:22751294

  13. Photophobic behavior of maize roots.

    PubMed

    Burbach, Christian; Markus, Katharina; Zhang, Yin; Schlicht, Markus; Baluška, František

    2012-07-01

    Primary roots of young maize seedlings showed peculiar growth behavior when challenged by placing them on a slope, or if whole seedlings were turned upside down. Importantly, this behavior was dependent on the light conditions. If roots were placed on slopes in the dark, they performed "crawling" behavior and advanced rapidly up the slope. However, as soon as these roots were illuminated, their crawling movements along their horizontal paths slowed down, and instead tried to grow downwards along the gravity vector. A similar light-induced switch in the root behavior was observed when roots were inverted, by placing them in thin glass capillaries. As long as they were kept in the darkness, they showed rapid growth against the gravity vector. If illuminated, these inverted roots rapidly accomplished U-turns and grew down along the gravity vector, eventually escaping from the capillaries upon reaching their open ends. De-capped roots, although growing vigorously, did not display these light-induced photophobic growth responses. We can conclude that intact root cap is essential for the photophobic root behavior in maize. PMID:22751294

  14. The radiative and hydrologic effects of a local switch from maize to miscanthus

    NASA Astrophysics Data System (ADS)

    Roy, Gavin R.

    Miscanthus (Miscanthus giganteus), a lush, dense grass that grows to be 3-4 meters tall, has been proven to be a substantially more productive biofuel crop than maize (Zea mays) due to its higher biomass output per unit area for conversion into ethanol. Moreover, Miscanthus is a perennial, biogeochemically sustainable crop, returning most of its nutrients to the soil each fall and needing less year-to-year maintenance than maize after its initial planting. Due to these potential benefits, a switch to Miscanthus as a viable biofuel alternative to maize has been suggested as a way to meet the current US energy goal of 30% displacement of domestic petroleum use by ethanol in the transportation sector by 2030, a goal that the existing US maize crop alone cannot achieve. Because maize and Miscanthus have significantly different vegetation characteristics, however, it is hypothesized that such a switch will lead to changes in the local surface radiation budget and hydrology. This study seeks to evaluate these changes. Perennial agriculture such as Miscanthus contributes to a greener surface earlier in the spring and later in the fall than maize (annual agriculture), subsequently leading to higher year-round albedo and water usage. Due to the denser growth of Miscanthus, evapotranspiration and thus absolute water usage are also higher than maize, especially during the summer. However, Miscanthus exhibits a deeper rooting depth than maize and therefore has access to deeper soil water. In this study, representative shifts in year-round albedo, green vegetation fraction, rooting depth, and leaf area index are parameterized and their combined radiative and hydrologic effects evaluated through uncoupled retrospective runs of a well-tested land surface model over an existing area of maize in the US Corn Belt. Sensitivity experiments are undertaken that likewise evaluate the individual contributions of each shifted parameterization scheme. It is found that the combination of

  15. [Effects of long-term different fertilizations on biomass and nutrient content of maize root].

    PubMed

    Cai, Miao; Meng, Yan; Mohammad Amin, Ahmadzai; Zhou, Jian-bin

    2015-08-01

    Taking two long-term local field trials at the south edge of the Loess Plateau, which were found in 1990 and 2003, respectively, as test subjects, the effects of different fertilization practices on the maize root biomass and nutrient content were investigated in this paper. Maize roots in the 0-20 cm top soil post-maize harvest from the different fertilization practices were collected by hand in October 2011. The results showed that compared with control without fertilization and N, NK, or PK treatments, the NP, NPK, fertilizers plus manure (M1NPK and M2NPK) or plus straw return (SNPK) treatments significantly increased the dry mass of maize root. The C, N, P and K contents in maize roots in the NP, NPK, M1 NPK, M2NPK and SNPK treatments were also significantly higher than those of control, especially in the NPK plus organic manure treatments (M1 NPK and M2NPK) in the trial. Compared with the N fertilizer free treatment (N0), root biomass in the 120 kg N · hm(-2) (N120) and 240 kg N · hm(-2) ( N240) fertilization treatments increased by 38% and 45%, respectively, but there was no significant difference between N120 and N240 treatments. Nitrogen fertilizer application (N120 and N240) also improved the C, N, P and K contents in maize root. The water soluble organic C and total soluble N contents of maize root in the NP, NPK, M1NPK, M2NPK, SNPK and the N120 and N240 treatments were greater than those of control and other treatments. Otherwise, the cellulose and lignin contents in maize roots declined in the NPK, M1NPK, M2NPK, and SNPK treatments compared with other treatments. So the root C/N and lignin/N ratios in the control, PK and N0 treatments were significantly higher than those in the NP, NPK, M1NPK, M2NPK and SNPK treatments. We concluded that the optimum fertilization (e. g., NP, NPK, MNPK and SNPK treatments) could increase maize root growth and nutrient content and improve soil fertility and carbon sequestration through root residue into soil. PMID

  16. [Effects of long-term different fertilizations on biomass and nutrient content of maize root].

    PubMed

    Cai, Miao; Meng, Yan; Mohammad Amin, Ahmadzai; Zhou, Jian-bin

    2015-08-01

    Taking two long-term local field trials at the south edge of the Loess Plateau, which were found in 1990 and 2003, respectively, as test subjects, the effects of different fertilization practices on the maize root biomass and nutrient content were investigated in this paper. Maize roots in the 0-20 cm top soil post-maize harvest from the different fertilization practices were collected by hand in October 2011. The results showed that compared with control without fertilization and N, NK, or PK treatments, the NP, NPK, fertilizers plus manure (M1NPK and M2NPK) or plus straw return (SNPK) treatments significantly increased the dry mass of maize root. The C, N, P and K contents in maize roots in the NP, NPK, M1 NPK, M2NPK and SNPK treatments were also significantly higher than those of control, especially in the NPK plus organic manure treatments (M1 NPK and M2NPK) in the trial. Compared with the N fertilizer free treatment (N0), root biomass in the 120 kg N · hm(-2) (N120) and 240 kg N · hm(-2) ( N240) fertilization treatments increased by 38% and 45%, respectively, but there was no significant difference between N120 and N240 treatments. Nitrogen fertilizer application (N120 and N240) also improved the C, N, P and K contents in maize root. The water soluble organic C and total soluble N contents of maize root in the NP, NPK, M1NPK, M2NPK, SNPK and the N120 and N240 treatments were greater than those of control and other treatments. Otherwise, the cellulose and lignin contents in maize roots declined in the NPK, M1NPK, M2NPK, and SNPK treatments compared with other treatments. So the root C/N and lignin/N ratios in the control, PK and N0 treatments were significantly higher than those in the NP, NPK, M1NPK, M2NPK and SNPK treatments. We concluded that the optimum fertilization (e. g., NP, NPK, MNPK and SNPK treatments) could increase maize root growth and nutrient content and improve soil fertility and carbon sequestration through root residue into soil.

  17. Lactobacillus rhamnosus as additive for maize and sorghum ensiling.

    PubMed

    Salimei, Elisabetta; Capilongo, Valeria; Simoni, Andrea; Peiretti, Pier Giorgio; Maglieri, Cristina; Romano, Cristina A; Mannina, Luisa; Coppola, Raffaele; Sorrentino, Elena

    2007-11-14

    The effects of Lactobacillus rhamnosus AT195, a potential probiotic microorganism cultured in buffalo "scotta" whey, on chemical and microbiological composition in maize and sorghum ensiling were evaluated. Both crops were harvested, chopped, and treated or not with the selected strain prior to ensiling in fiberglass vertical silos; 90 days after ensiling, silages were sensorially evaluated and sampled. Different chemical components were evaluated both on fresh crops and silages: in particular, the water-soluble carbohydrates content was investigated by high-field NMR spectroscopy and the carbohydrate fermentation profile was performed by GC. Besides phenotypic identification and typing, microbiological studies included Lb. rhamnosus genotype typing by RAPD-PCR. All silages, inoculated or not, were well preserved, as their chemical and microbiological data along with the fermentation profiles showed. The selected strain used as inoculum influenced the lactic acid population of silages and evidenced a good survival performance during the ensiling process of both maize and sorghum. Moreover, the use of Lb. rhamnosus strain efficiently improved the quality of the multifactorial ensiling process by significantly reducing the ammonia nitrogen content of both maize and sorghum silages.

  18. MaizeGDB: The Maize Model Organism Database for Basic, Translational, and Applied Research

    PubMed Central

    Lawrence, Carolyn J.; Harper, Lisa C.; Schaeffer, Mary L.; Sen, Taner Z.; Seigfried, Trent E.; Campbell, Darwin A.

    2008-01-01

    In 2001 maize became the number one production crop in the world with the Food and Agriculture Organization of the United Nations reporting over 614 million tonnes produced. Its success is due to the high productivity per acre in tandem with a wide variety of commercial uses. Not only is maize an excellent source of food, feed, and fuel, but also its by-products are used in the production of various commercial products. Maize's unparalleled success in agriculture stems from basic research, the outcomes of which drive breeding and product development. In order for basic, translational, and applied researchers to benefit from others' investigations, newly generated data must be made freely and easily accessible. MaizeGDB is the maize research community's central repository for genetics and genomics information. The overall goals of MaizeGDB are to facilitate access to the outcomes of maize research by integrating new maize data into the database and to support the maize research community by coordinating group activities. PMID:18769488

  19. Effect of Stacked Insecticidal Cry Proteins from Maize Pollen on Nurse Bees (Apis mellifera carnica) and Their Gut Bacteria

    PubMed Central

    Härtel, Stephan; Näther, Astrid; Dohrmann, Anja B.; Steffan-Dewenter, Ingolf; Tebbe, Christoph C.

    2013-01-01

    Honey bee pollination is a key ecosystem service to nature and agriculture. However, biosafety research on genetically modified crops rarely considers effects on nurse bees from intact colonies, even though they receive and primarily process the largest amount of pollen. The objective of this study was to analyze the response of nurse bees and their gut bacteria to pollen from Bt maize expressing three different insecticidal Cry proteins (Cry1A.105, Cry2Ab2, and Cry3Bb1). Naturally Cry proteins are produced by bacteria (Bacillus thuringiensis). Colonies of Apis mellifera carnica were kept during anthesis in flight cages on field plots with the Bt maize, two different conventionally bred maize varieties, and without cages, 1-km outside of the experimental maize field to allow ad libitum foraging to mixed pollen sources. During their 10-days life span, the consumption of Bt maize pollen had no effect on their survival rate, body weight and rates of pollen digestion compared to the conventional maize varieties. As indicated by ELISA-quantification of Cry1A.105 and Cry3Bb1, more than 98% of the recombinant proteins were degraded. Bacterial population sizes in the gut were not affected by the genetic modification. Bt-maize, conventional varieties and mixed pollen sources selected for significantly different bacterial communities which were, however, composed of the same dominant members, including Proteobacteria in the midgut and Lactobacillus sp. and Bifidobacterium sp. in the hindgut. Surprisingly, Cry proteins from natural sources, most likely B. thuringiensis, were detected in bees with no exposure to Bt maize. The natural occurrence of Cry proteins and the lack of detectable effects on nurse bees and their gut bacteria give no indication for harmful effects of this Bt maize on nurse honey bees. PMID:23533634

  20. Quality assessment of maize assembled genomic islands (MAGIs) and large-scale experimental verification of predicted genes.

    PubMed

    Fu, Yan; Emrich, Scott J; Guo, Ling; Wen, Tsui-Jung; Ashlock, Daniel A; Aluru, Srinivas; Schnable, Patrick S

    2005-08-23

    Recent sequencing efforts have targeted the gene-rich regions of the maize (Zea mays L.) genome. We report the release of an improved assembly of maize assembled genomic islands (MAGIs). The 114,173 resulting contigs have been subjected to computational and physical quality assessments. Comparisons to the sequences of maize bacterial artificial chromosomes suggest that at least 97% (160 of 165) of MAGIs are correctly assembled. Because the rates at which junction-testing PCR primers for genomic survey sequences (90-92%) amplify genomic DNA are not significantly different from those of control primers ( approximately 91%), we conclude that a very high percentage of genic MAGIs accurately reflect the structure of the maize genome. EST alignments, ab initio gene prediction, and sequence similarity searches of the MAGIs are available at the Iowa State University MAGI web site. This assembly contains 46,688 ab initio predicted genes. The expression of almost half (628 of 1,369) of a sample of the predicted genes that lack expression evidence was validated by RT-PCR. Our analyses suggest that the maize genome contains between approximately 33,000 and approximately 54,000 expressed genes. Approximately 5% (32 of 628) of the maize transcripts discovered do not have detectable paralogs among maize ESTs or detectable homologs from other species in the GenBank NR nucleotide/protein database. Analyses therefore suggest that this assembly of the maize genome contains approximately 350 previously uncharacterized expressed genes. We hypothesize that these "orphans" evolved quickly during maize evolution and/or domestication.

  1. Effect of stacked insecticidal Cry proteins from maize pollen on nurse bees (Apis mellifera carnica) and their gut bacteria.

    PubMed

    Hendriksma, Harmen P; Küting, Meike; Härtel, Stephan; Näther, Astrid; Dohrmann, Anja B; Steffan-Dewenter, Ingolf; Tebbe, Christoph C

    2013-01-01

    Honey bee pollination is a key ecosystem service to nature and agriculture. However, biosafety research on genetically modified crops rarely considers effects on nurse bees from intact colonies, even though they receive and primarily process the largest amount of pollen. The objective of this study was to analyze the response of nurse bees and their gut bacteria to pollen from Bt maize expressing three different insecticidal Cry proteins (Cry1A.105, Cry2Ab2, and Cry3Bb1). Naturally Cry proteins are produced by bacteria (Bacillus thuringiensis). Colonies of Apis mellifera carnica were kept during anthesis in flight cages on field plots with the Bt maize, two different conventionally bred maize varieties, and without cages, 1-km outside of the experimental maize field to allow ad libitum foraging to mixed pollen sources. During their 10-days life span, the consumption of Bt maize pollen had no effect on their survival rate, body weight and rates of pollen digestion compared to the conventional maize varieties. As indicated by ELISA-quantification of Cry1A.105 and Cry3Bb1, more than 98% of the recombinant proteins were degraded. Bacterial population sizes in the gut were not affected by the genetic modification. Bt-maize, conventional varieties and mixed pollen sources selected for significantly different bacterial communities which were, however, composed of the same dominant members, including Proteobacteria in the midgut and Lactobacillus sp. and Bifidobacterium sp. in the hindgut. Surprisingly, Cry proteins from natural sources, most likely B. thuringiensis, were detected in bees with no exposure to Bt maize. The natural occurrence of Cry proteins and the lack of detectable effects on nurse bees and their gut bacteria give no indication for harmful effects of this Bt maize on nurse honey bees. PMID:23533634

  2. Measuring and modeling maize evapotranspiration under plastic film-mulching condition

    NASA Astrophysics Data System (ADS)

    Li, Sien; Kang, Shaozhong; Zhang, Lu; Ortega-Farias, Samuel; Li, Fusheng; Du, Taisheng; Tong, Ling; Wang, Sufen; Ingman, Mark; Guo, Weihua

    2013-10-01

    Plastic film-mulching techniques have been widely used over a variety of agricultural crops for saving water and improving yield. Accurate estimation of crop evapotranspiration (ET) under the film-mulching condition is critical for optimizing crop water management. After taking the mulching effect on soil evaporation (Es) into account, our study adjusted the original Shuttleworth-Wallace model (MSW) in estimating maize ET and Es under the film-mulching condition. Maize ET and Es respectively measured by eddy covariance and micro-lysimeter methods during 2007 and 2008 were used to validate the performance of the Penman-Monteith (PM), the original Shuttleworth-Wallace (SW) and the MSW models in arid northwest China. Results indicate that all three models significantly overestimated ET during the initial crop stage in the both years, which may be due to the underestimation of canopy resistance induced by the Jarvis model for the drought stress in the stage. For the entire experimental period, the SW model overestimated half-hourly maize ET by 17% compared with the eddy covariance method (ETEC) and overestimated daily Es by 241% compared with the micro-lysimeter measurements (EL), while the PM model only underestimated daily maize ET by 6%, and the MSW model only underestimated half-hourly maize ET by 2% and Es by 7% during the whole period. Thus the PM and MSW models significantly improved the accuracy against the original SW model and can be used to estimate ET and Es under the film-mulching condition.

  3. Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils

    PubMed Central

    Odebode, A. C.; Hsu, S. F.

    2015-01-01

    Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with in situ microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in in vitro assays of antagonistic activity against a local strain of Fusarium verticillioides, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a Bacillus strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments. PMID:25956774

  4. Impact of mechanical shelling and dehulling on Fusarium infection and fumonisin contamination in maize.

    PubMed

    Fandohan, P; Ahouansou, R; Houssou, P; Hell, K; Marasas, W F O; Wingfield, M J

    2006-04-01

    Mechanical shelling and dehulling methods were tested to evaluate their impact on Fusarium infection and fumonisin contamination in maize. All shelling methods which were tested were found to damage the grains. The IITA sheller caused the highest level (up to 3.5%) of damage. Fusarium populations were higher on damaged grains, the highest being recorded from grains damaged by the IITA sheller (2,533.3 cfu g(-1)). Fumonisin levels were higher in damaged grains, the highest being in maize shelled with the IITA sheller (2.2 mg kg(-1)). Fumonisin levels were positively and significantly correlated with the percentage of damage caused by the shelling methods, and with the number of Fusarium colonies in maize. Mechanical dehulling methods significantly reduced fumonisin levels in maize, resulting in a mean reduction of 62% for Mini-PRL, 65% for Engelberg, and 57% for the attrition disc mill. It is important for farmers to choose appropriate shelling methods to reduce mycotoxin contamination. Dehulling should be widely promoted for the reduction of mycotoxins in maize. PMID:16546888

  5. [Effects of organic fertilizer application rate on leaf photosynthetic characteristics and grain yield of dryland maize].

    PubMed

    Wang, Xiao-Juan; Jia, Zhi-Kuan; Liang, Lian-You; Ding, Rui-Xia; Wang, Min; Li, Han

    2012-02-01

    A 4-year field experiment was conducted at the Heyang Research Station in Weibei dryland to study the effects of organic fertilizer application rate on the leaf photosynthetic characteristics and grain yield of dryland maize. Comparing with applying chemical fertilizer, applying organic fertilizer increased the leaf photosynthetic rate and stomatal conductance, but decreased the leaf intercellular CO2 concentration at each growth stage of maize significantly. With the increasing application rate of organic fertilizer, the leaf photosynthetic rate and stomatal conductance at each growth stage of maize had a gradual increase, while the leaf intercellular CO2 concentration had a gradual decrease. The leaf photosynthesis of maize at each growth stage was controlled by non-stomatal factors, and the application of organic fertilizer reduced the non-stomatal limitation on the photosynthesis performance significantly. The 4-year application of organic fertilizer improved soil nutrient status, and soil nutrients were no longer the main factors limiting the leaf photosynthetic rate and grain yield of maize. PMID:22586967

  6. Inhibition of polyamine oxidase activity affects tumor development during the maize-Ustilago maydis interaction.

    PubMed

    Jasso-Robles, Francisco Ignacio; Jiménez-Bremont, Juan Francisco; Becerra-Flora, Alicia; Juárez-Montiel, Margarita; Gonzalez, María Elisa; Pieckenstain, Fernando Luis; García de la Cruz, Ramón Fernando; Rodríguez-Kessler, Margarita

    2016-05-01

    Ustilago maydis is a biotrophic plant pathogenic fungus that leads to tumor development in the aerial tissues of its host, Zea mays. These tumors are the result of cell hypertrophy and hyperplasia, and are accompanied by the reprograming of primary and secondary metabolism of infected plants. Up to now, little is known regarding key plant actors and their role in tumor development during the interaction with U. maydis. Polyamines are small aliphatic amines that regulate plant growth, development and stress responses. In a previous study, we found substantial increases of polyamine levels in tumors. In the present work, we describe the maize polyamine oxidase (PAO) gene family, its contribution to hydrogen peroxide (H2O2) production and its possible role in tumor development induced by U. maydis. Histochemical analysis revealed that chlorotic lesions and maize tumors induced by U. maydis accumulate H2O2 to significant levels. Maize plants inoculated with U. maydis and treated with the PAO inhibitor 1,8-diaminooctane exhibit a notable reduction of H2O2 accumulation in infected tissues and a significant drop in PAO activity. This treatment also reduced disease symptoms in infected plants. Finally, among six maize PAO genes only the ZmPAO1, which encodes an extracellular enzyme, is up-regulated in tumors. Our data suggest that H2O2 produced through PA catabolism by ZmPAO1 plays an important role in tumor development during the maize-U. maydis interaction.

  7. Phytobeneficial Properties of Bacteria Isolated from the Rhizosphere of Maize in Southwestern Nigerian Soils.

    PubMed

    Abiala, M A; Odebode, A C; Hsu, S F; Blackwood, C B

    2015-07-01

    Biocontrol agents isolated outside Africa have performed inconsistently under field conditions in Africa. The development of indigenous phytobeneficial microbial strains that suit local environments may help enhance competitiveness with in situ microorganisms and effectiveness at suppressing local pathogen strains. We isolated bacteria from the rhizosphere of maize growing in southwestern Nigeria and assessed them for growth-promoting characteristics. The best isolates were characterized using 16S rRNA genes and were further evaluated in the greenhouse on maize seedlings. Four isolates (EBS8, IGBR11, EPR2, and ADS14) were outstanding in in vitro assays of antagonistic activity against a local strain of Fusarium verticillioides, phosphate solubilization efficiency, chitinase enzyme activity, and indole-3-acetic acid production. Inoculation of maize seeds with these isolates resulted in ≥95% maize seed germination and significantly enhanced radicle and plumule length. In the greenhouse, maize seedling height, stem girth, number of leaves, leaf area, shoot mass (dry matter), and nutrient contents were significantly enhanced. The bioprotectant and phytobeneficial effects were strongest and most consistent for isolate EBS8, which was identified as a Bacillus strain by 16S rRNA gene analysis. As a bacterial strain that exhibits multiple growth-promoting characteristics and is adapted to local conditions, EBS8 should be considered for the development of indigenous biological fertilizer treatments. PMID:25956774

  8. [Effects of organic fertilizer application rate on leaf photosynthetic characteristics and grain yield of dryland maize].

    PubMed

    Wang, Xiao-Juan; Jia, Zhi-Kuan; Liang, Lian-You; Ding, Rui-Xia; Wang, Min; Li, Han

    2012-02-01

    A 4-year field experiment was conducted at the Heyang Research Station in Weibei dryland to study the effects of organic fertilizer application rate on the leaf photosynthetic characteristics and grain yield of dryland maize. Comparing with applying chemical fertilizer, applying organic fertilizer increased the leaf photosynthetic rate and stomatal conductance, but decreased the leaf intercellular CO2 concentration at each growth stage of maize significantly. With the increasing application rate of organic fertilizer, the leaf photosynthetic rate and stomatal conductance at each growth stage of maize had a gradual increase, while the leaf intercellular CO2 concentration had a gradual decrease. The leaf photosynthesis of maize at each growth stage was controlled by non-stomatal factors, and the application of organic fertilizer reduced the non-stomatal limitation on the photosynthesis performance significantly. The 4-year application of organic fertilizer improved soil nutrient status, and soil nutrients were no longer the main factors limiting the leaf photosynthetic rate and grain yield of maize.

  9. Interactive effects on CO2, drought, and ultraviolet-B radiation on maize growth and development.

    PubMed

    Wijewardana, Chathurika; Henry, W Brien; Gao, Wei; Reddy, K Raja

    2016-07-01

    Crop growth and development are highly responsive to global climate change components such as elevated carbon dioxide (CO2), drought, and ultraviolet-B (UV-B) radiation. Plant tolerance to these environmental stresses comprises its genetic potential, physiological changes, metabolism, and signaling pathways. An inclusive understanding of morphological, physiological, and biochemical responses to these abiotic stresses is imperative for the development of stress tolerant varieties for future environments. The objectives of this study were to characterize the changes in vegetative and physiological traits in maize hybrids in their response to multiple environmental factors of (CO2) [400 and 750μmolmol(-1) (+(CO2)], irrigation treatments based evapotranspiration (ET) [100 and 50% (-ET)], and UV-B radiation [0 and 10kJm(-2)d(-1) (+UV-B)] and to identify the multiple stress tolerant hybrids aid in mitigating projected climate change for shaping future agriculture. Six maize hybrids (P1498, DKC 65-81, N75H-GTA, P1319, DKC 66-97, and N77P-3111) with known drought tolerance variability were grown in eight sunlit, controlled environment chambers in which control treatment consisted of 400μmolmol(-1) [CO2], 100% ET-based irrigation, and 0kJ UV-B. Plants grown at +UV-B alone or combination with 50% ET produced shorter plants and smaller leaf area while elevated CO2 treatments ameliorated the damaging effects of drought and higher UV-B levels on maize hybrids. Plant height, leaf area, total dry matter chlorophyll, carotenoids, and net photosynthesis measured were increased in response to CO2 enrichment. Total stress response index (TSRI) for each hybrid, developed from the cumulative sum of response indices of vegetative and physiological parameters, varied among the maize hybrids. The hybrids were classified as tolerant (P1498), intermediate (DKC 65-81, N75H-GTA, N77P-3111) and sensitive (P1319 and DKC 66-97) to multiple environmental stresses. The positive correlation

  10. Interactive effects on CO2, drought, and ultraviolet-B radiation on maize growth and development.

    PubMed

    Wijewardana, Chathurika; Henry, W Brien; Gao, Wei; Reddy, K Raja

    2016-07-01

    Crop growth and development are highly responsive to global climate change components such as elevated carbon dioxide (CO2), drought, and ultraviolet-B (UV-B) radiation. Plant tolerance to these environmental stresses comprises its genetic potential, physiological changes, metabolism, and signaling pathways. An inclusive understanding of morphological, physiological, and biochemical responses to these abiotic stresses is imperative for the development of stress tolerant varieties for future environments. The objectives of this study were to characterize the changes in vegetative and physiological traits in maize hybrids in their response to multiple environmental factors of (CO2) [400 and 750μmolmol(-1) (+(CO2)], irrigation treatments based evapotranspiration (ET) [100 and 50% (-ET)], and UV-B radiation [0 and 10kJm(-2)d(-1) (+UV-B)] and to identify the multiple stress tolerant hybrids aid in mitigating projected climate change for shaping future agriculture. Six maize hybrids (P1498, DKC 65-81, N75H-GTA, P1319, DKC 66-97, and N77P-3111) with known drought tolerance variability were grown in eight sunlit, controlled environment chambers in which control treatment consisted of 400μmolmol(-1) [CO2], 100% ET-based irrigation, and 0kJ UV-B. Plants grown at +UV-B alone or combination with 50% ET produced shorter plants and smaller leaf area while elevated CO2 treatments ameliorated the damaging effects of drought and higher UV-B levels on maize hybrids. Plant height, leaf area, total dry matter chlorophyll, carotenoids, and net photosynthesis measured were increased in response to CO2 enrichment. Total stress response index (TSRI) for each hybrid, developed from the cumulative sum of response indices of vegetative and physiological parameters, varied among the maize hybrids. The hybrids were classified as tolerant (P1498), intermediate (DKC 65-81, N75H-GTA, N77P-3111) and sensitive (P1319 and DKC 66-97) to multiple environmental stresses. The positive correlation

  11. Different effects of transgenic maize and nontransgenic maize on nitrogen-transforming archaea and bacteria in tropical soils.

    PubMed

    Cotta, Simone Raposo; Dias, Armando Cavalcante Franco; Marriel, Ivanildo Evódio; Andreote, Fernando Dini; Seldin, Lucy; van Elsas, Jan Dirk

    2014-10-01

    The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCR-denaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants. PMID:25107970

  12. A large and deep root system underlies high nitrogen-use efficiency in maize production.

    PubMed

    Yu, Peng; Li, Xuexian; White, Philip J; Li, Chunjian

    2015-01-01

    Excessive N fertilization results in low N-use efficiency (NUE) without any yield benefits and can have profound, long-term environmental consequences including soil acidification, N leaching and increased production of greenhouse gases. Improving NUE in crop production has been a longstanding, worldwide challenge. A crucial strategy to improve NUE is to enhance N uptake by roots. Taking maize as a model crop, we have compared root dry weight (RDW), root/shoot biomass ratio (R/S), and NUE of maize grown in the field in China and in western countries using data from 106 studies published since 1959. Detailed analysis revealed that the differences in the RDW and R/S of maize at silking in China and the western countries were not derived from variations in climate, geography, and stress factors. Instead, NUE was positively correlated with R/S and RDW; R/S and NUE of maize varieties grown in western countries were significantly greater than those grown in China. We then testified this conclusion by conducting field trials with representative maize hybrids in China (ZD958 and XY335) and the US (P32D79). We found that US P32D79 had a better root architecture for increased N uptake and removed more mineral N than Chinese cultivars from the 0-60 cm soil profile. Reported data and our field results demonstrate that a large and deep root, with an appropriate architecture and higher stress tolerance (higher plant density, drought and N deficiency), underlies high NUE in maize production. We recommend breeding for these traits to reduce the N-fertilizer use and thus N-leaching in maize production and paying more attention to increase tolerance to stresses in China. PMID:25978356

  13. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas

    PubMed Central

    Ortiz, Carlos S.; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-01-01

    Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field. PMID:26361468

  14. A Large and Deep Root System Underlies High Nitrogen-Use Efficiency in Maize Production

    PubMed Central

    Yu, Peng; Li, Xuexian; White, Philip J.; Li, Chunjian

    2015-01-01

    Excessive N fertilization results in low N-use efficiency (NUE) without any yield benefits and can have profound, long-term environmental consequences including soil acidification, N leaching and increased production of greenhouse gases. Improving NUE in crop production has been a longstanding, worldwide challenge. A crucial strategy to improve NUE is to enhance N uptake by roots. Taking maize as a model crop, we have compared root dry weight (RDW), root/shoot biomass ratio (R/S), and NUE of maize grown in the field in China and in western countries using data from 106 studies published since 1959. Detailed analysis revealed that the differences in the RDW and R/S of maize at silking in China and the western countries were not derived from variations in climate, geography, and stress factors. Instead, NUE was positively correlated with R/S and RDW; R/S and NUE of maize varieties grown in western countries were significantly greater than those grown in China. We then testified this conclusion by conducting field trials with representative maize hybrids in China (ZD958 and XY335) and the US (P32D79). We found that US P32D79 had a better root architecture for increased N uptake and removed more mineral N than Chinese cultivars from the 0-60 cm soil profile. Reported data and our field results demonstrate that a large and deep root, with an appropriate architecture and higher stress tolerance (higher plant density, drought and N deficiency), underlies high NUE in maize production. We recommend breeding for these traits to reduce the N-fertilizer use and thus N-leaching in maize production and paying more attention to increase tolerance to stresses in China. PMID:25978356

  15. Choosing a Genome Browser for a Model Organism Database (MOD): Surveying the Maize Community

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the maize genome sequencing is nearing its completion, the Maize Genetics and Genomics Database (MaizeGDB), the Model Organism Database for maize, integrated a genome browser to its already existing Web interface and database. The addition of the MaizeGDB Genome Browser to MaizeGDB will allow it ...

  16. The effect of moisture content on grinding process of wheat and maize single kernel

    NASA Astrophysics Data System (ADS)

    Lupu, M. I.; Pădureanu, V.; Canja, C. M.; Măzărel, A.

    2016-08-01

    The mechanical properties and the resistance of grains are key characteristics that enhance grinding behaviour of wheat and maize and are dependent on the moisture content of the grains. These properties were defined in the single-kernel compression test, and it seems that the qualities expressing the relations resulting during mechanical loads like mechanical and rheological properties are significant. The aim of the study reported here is to show the influence of moisture content on grinding process of wheat and maize single kernel. To show this influence it is necessary to study the physical and mechanical properties of wheat and maize single kernel at different moisture content 10%, 12%, 14%, 16%, 18% and 20%. The measurement results showed significant relationship between the cereal type, its resistance characteristics and the moisture content in the grinding process.

  17. Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley.

    PubMed

    Ruiz, E; Alonso-Azcárate, J; Rodríguez, L

    2011-03-01

    The effect of the earthworm Lumbricus terrestris L. on metal availability in two mining soils was assessed by means of chemical extraction methods and a pot experiment using crop plants. Results from single and sequential extractions showed that L. terrestris had a slight effect on metal fractionation in the studied soils: only metals bound to the soil organic matter were significantly increased in some cases. However, we found that L. terrestris significantly increased root, shoot and total Pb and Zn concentrations in maize and barley for the soil with the highest concentrations of total and available metals. Specifically, shoot Pb concentration was increased by a factor of 7.5 and 3.9 for maize and barley, respectively, while shoot Zn concentration was increased by a factor of 3.7 and 1.7 for maize and barley, respectively. Our results demonstrated that earthworm activity increases the bioavailability of metals in soils. PMID:21190761

  18. Effects of chitin nano-whiskers on the gelatinization and retrogradation of maize and potato starches.

    PubMed

    Ji, Na; Liu, Chengzhen; Zhang, Shuangling; Yu, Jing; Xiong, Liu; Sun, Qingjie

    2017-01-01

    Starch is very prone to retrogradation after gelatinization. Inhibition of starch retrogradation has been an important factor in improving the quality of food. For the first time, we investigated the effect of nano-materials, represented by chitin nano-whiskers (CNWs), on the short- and long-term retrogradation of maize and potato starches. Rapid Visco-Analyser results showed that the addition of CNWs significantly decreased the setback values of maize and potato starches, which suggested that CNWs could retard the short-term retrogradation of starch. Differential scanning calorimetry and X-ray diffraction results showed that the percentage of retrogradation of maize and potato starches significantly decreased (P<0.05), suggesting the inhibition of long-term retrogradation. The CNWs could be used as a new inhibitor of starch retrogradation to develop starch-based food with longer shelf life. PMID:27507508

  19. Relationship of crop radiance to alfalfa agronomic values

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Elgin, J. H., Jr.; Mcmurtrey, J. E., III

    1980-01-01

    Red and photographic infrared spectral data of alfalfa were collected at the time of the third and fourth cuttings using a hand-held radiometer for the earlier alfalfa cutting. Significant linear and non-linear correlation coefficients were found between the spectral variables and plant height, biomass, forage water content, and estimated canopy cover. For the alfalfa of the later cutting, which had experienced a period of severe drought stress which limited growth, the spectral variables were found to be highly correlated with the estimated drought scores.

  20. QTL of three agronomically important traits and their interactions with environment in a European x Chinese rapeseed population.

    PubMed

    Zhao, Jian-Yi; Becker, Heiko C; Ding, Hou-Dong; Zhang, Yao-Feng; Zhang, Dong-Qing; Ecke, Wolfgang

    2005-09-01

    A rapeseed population consisted of 282 doubled haploid (DH) lines derived from a cross between a European vality "Sallux" and a Chinese inbred line "Gaoyou" was planted in 4 locations, 2 in Xi'an and Hangzhou, China, and 2 in Goettingen, Germany. Field experiments were carried out to obtain agronomically phenotypic data from above four environments. A linkage map including 125 SSR-markers was constructed and QTL analyses was performed using mixed model approach to detect QTLs showing additive (a), epistasis (aa) as well as their interactions with environments (QE) for three important agronomic traits: plant height, flowering time and maturity. The results demonstrated that each trait was controlled by several QTLs with additive effect and a number of QTLs with epistatic and QE interaction effects. Plant height was controlled by many QTLs (12 loci with a or combined ae, 5 loci with ae). Additive effects were predominant,totally explained 75% of the phenotypic variation and often combined with digenic epistasis. Of 12 main QTLs, 9 showed Gaoyou alleles decreasing plant height. Most of QTLs with QE effects showed ecologically favourable alleles in diverse regions. Five of 7 ae loci showed Gaoyou alleles in Hangzhou and all the ae loci but one had Sollux alleles in two locations of Germany increasing plant height. The digenic epistatic main effect accounted for one third of total additive main effects. In this study,we discovered 7 and 8 loci having significant additive main effects upon flowering time and maturity, respectively. Of them, early flowering and maturity alleles were respectively 6 and 5 derived from Chinese parent Gaoyou. All these QTLs together accounted for around 60% of the phenotypic variation for each trait. Significant ae interactions were detected for flowering time and maturity and parental alleles showed almost evenly dispersal at all environments. Three of 8 main QTLs for maturity were located at similar or identical positions as QTLs for

  1. QTL of three agronomically important traits and their interactions with environment in a European x Chinese rapeseed population.

    PubMed

    Zhao, Jian-Yi; Becker, Heiko C; Ding, Hou-Dong; Zhang, Yao-Feng; Zhang, Dong-Qing; Ecke, Wolfgang

    2005-09-01

    A rapeseed population consisted of 282 doubled haploid (DH) lines derived from a cross between a European vality "Sallux" and a Chinese inbred line "Gaoyou" was planted in 4 locations, 2 in Xi'an and Hangzhou, China, and 2 in Goettingen, Germany. Field experiments were carried out to obtain agronomically phenotypic data from above four environments. A linkage map including 125 SSR-markers was constructed and QTL analyses was performed using mixed model approach to detect QTLs showing additive (a), epistasis (aa) as well as their interactions with environments (QE) for three important agronomic traits: plant height, flowering time and maturity. The results demonstrated that each trait was controlled by several QTLs with additive effect and a number of QTLs with epistatic and QE interaction effects. Plant height was controlled by many QTLs (12 loci with a or combined ae, 5 loci with ae). Additive effects were predominant,totally explained 75% of the phenotypic variation and often combined with digenic epistasis. Of 12 main QTLs, 9 showed Gaoyou alleles decreasing plant height. Most of QTLs with QE effects showed ecologically favourable alleles in diverse regions. Five of 7 ae loci showed Gaoyou alleles in Hangzhou and all the ae loci but one had Sollux alleles in two locations of Germany increasing plant height. The digenic epistatic main effect accounted for one third of total additive main effects. In this study,we discovered 7 and 8 loci having significant additive main effects upon flowering time and maturity, respectively. Of them, early flowering and maturity alleles were respectively 6 and 5 derived from Chinese parent Gaoyou. All these QTLs together accounted for around 60% of the phenotypic variation for each trait. Significant ae interactions were detected for flowering time and maturity and parental alleles showed almost evenly dispersal at all environments. Three of 8 main QTLs for maturity were located at similar or identical positions as QTLs for

  2. Open chromatin reveals the functional maize genome

    PubMed Central

    Rodgers-Melnick, Eli; Vera, Daniel L.; Bass, Hank W.

    2016-01-01

    Cellular processes mediated through nuclear DNA must contend with chromatin. Chromatin structural assays can efficiently integrate information across diverse regulatory elements, revealing the functional noncoding genome. In this study, we use a differential nuclease sensitivity assay based on micrococcal nuclease (MNase) digestion to discover open chromatin regions in the maize genome. We find that maize MNase-hypersensitive (MNase HS) regions localize around active genes and within recombination hotspots, focusing biased gene conversion at their flanks. Although MNase HS regions map to less than 1% of the genome, they consistently explain a remarkably large amount (∼40%) of heritable phenotypic variance in diverse complex traits. MNase HS regions are therefore on par with coding sequences as annotations that demarcate the functional parts of the maize genome. These results imply that less than 3% of the maize genome (coding and MNase HS regions) may give rise to the overwhelming majority of phenotypic variation, greatly narrowing the scope of the functional genome. PMID:27185945

  3. Relative contribution of shoot and ear photosynthesis to grain filling in wheat under good agronomical conditions assessed by differential organ δ13C

    PubMed Central

    Sanchez-Bragado, Rut; Molero, Gemma; Reynolds, Matthew P.; Araus, Jose Luis

    2014-01-01

    During grain filling in C3 cereals, the shoot (particularly the flag leaf) and the ear are believed to play major roles as sources of assimilates. However, both the cost and the intrusive nature of most of the methodologies available to investigate this have prevented conclusive results being obtained. This study compared the carbon isotope composition (δ13C) in its natural abundance in mature kernels with the δ13C of the water-soluble fraction of the peduncle, glumes, and awns to assess the relative contribution of the shoot (understood as the whole set of photosynthetic organs below the peduncle) and ear to grain filling in a set of highly productive wheat lines from the International Maize and Wheat Improvement Center, Mexico, under good agronomic conditions. In overall terms, the contribution of the ear was greater in comparison with that of the shoot. The specific contribution of the flag leaf blade to grain filling was also assessed by comparing the δ13C of grains with the δ13C of the water-soluble fraction of the flag leaf and the awns. The contribution of the flag leaf was minor, ranging between 3 and 18%. Complementary analyses performed such as gas-exchange rates and the accumulated water-soluble carbohydrates in both organs and light intercepted by the canopy at different strata suggested that the ear has a photosynthetic capacity at least comparable to that of the flag leaf. In this sense, selection for a higher contribution of ear photosynthesis to grain yield in breeding programmes could be addressed with the use of stable isotopes. PMID:25053645

  4. Sublethal effect of agronomical surfactants on the spider Pardosa agrestis.

    PubMed

    Niedobová, Jana; Hula, Vladimír; Michalko, Radek

    2016-06-01

    In addition to their active ingredients, pesticides contain also additives - surfactants. Use of surfactants has been increasing over the past decade, but their effects on non-target organisms, especially natural enemies of pests, have been studied only very rarely. The effect of three common agrochemical surfactants on the foraging behavior of the wolf spider Pardosa agrestis was studied in the laboratory. Differences in short-term, long-term, and overall cumulative predatory activities were investigated. We found that surfactant treatment significantly affected short-term predatory activity but had no effect on long-term predatory activity. The surfactants also significantly influenced the cumulative number of killed prey. We also found the sex-specific increase in cumulative kills after surfactants treatment. This is the first study showing that pesticide additives have a sublethal effect that can weaken the predatory activity of a potential biological control agent. More studies on the effects of surfactants are needed to understand how they affect beneficial organisms in agroecosystems. PMID:26878602

  5. Fusarium infection of maize and maize-based products and exposure of a rural population to fumonisin B₁ in Limpopo Province, South Africa.

    PubMed

    Phoku, J Z; Dutton, M F; Njobeh, P B; Mwanza, M; Egbuta, M A; Chilaka, C A

    2012-01-01

    Fusarium species (spp.) and fumonisin B₁ (FB₁) contaminations were monitored in maize and porridge consumed by a rural population of Limpopo Province, South Africa. Faecal samples were also analysed for FB₁ as a means of estimating the degree of dietary exposure to this mycotoxin. In total, 142 samples of maize (n = 54), porridge (47) and faeces (41) were screened for Fusarium spp. using a serial dilution technique followed by DNA sequencing, while FB₁ was further screened and quantified by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively. At least four species of Fusarium were identified, of which F. verticillioides was the most prevalent in all three sample types analysed. The contamination levels of FB₁ were significantly higher in 87% of maize sampled (range = 101-53,863 µg kg⁻¹) as compared with porridge (74% incidence rate; range = 0.2-20 µg kg⁻¹) and faecal samples (100% incidence rate; range = 0.3-464 µg kg⁻¹). Thus, it can be deduced that the level of human exposure to FB₁ via the consumption of maize was high as several samples contained levels exceeding 1000 µg kg⁻¹, which was strongly supported by the levels found in faecal samples. Further data revealed that a high proportion of FB₁ is destroyed or removed by processing maize into porridge. As maize porridge is consumed as a staple, the low levels found provide a means to limit exposure to FB₁. Levels of FB₁ found in the faeces which were higher indicate that other foods contaminated with the toxin are also consumed.

  6. Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid1[OPEN

    PubMed Central

    Louis, Joe; Basu, Saumik; Varsani, Suresh; Castano-Duque, Lina; Jiang, Victoria; Williams, W. Paul; Felton, Gary W.; Luthe, Dawn S.

    2015-01-01

    Signaling networks among multiple phytohormones fine-tune plant defense responses to insect herbivore attack. Previously, it was reported that the synergistic combination of ethylene (ET) and jasmonic acid (JA) was required for accumulation of the maize insect resistance1 (mir1) gene product, a cysteine (Cys) proteinase that is a key defensive protein against chewing insect pests in maize (Zea mays). However, this study suggests that mir1-mediated resistance to corn leaf aphid (CLA; Rhopalosiphum maidis), a phloem sap-sucking insect pest, is independent of JA but regulated by the ET-signaling pathway. Feeding by CLA triggers the rapid accumulation of mir1 transcripts in the resistant maize genotype, Mp708. Furthermore, Mp708 provided elevated levels of antibiosis (limits aphid population)- and antixenosis (deters aphid settling)-mediated resistance to CLA compared with B73 and Tx601 maize susceptible inbred lines. Synthetic diet aphid feeding trial bioassays with recombinant Mir1-Cys Protease demonstrates that Mir1-Cys Protease provides direct toxicity to CLA. Furthermore, foliar feeding by CLA rapidly sends defensive signal(s) to the roots that trigger belowground accumulation of the mir1, signifying a potential role of long-distance signaling in maize defense against the phloem-feeding insects. Collectively, our data indicate that ET-regulated mir1 transcript accumulation, uncoupled from JA, contributed to heightened resistance to CLA in maize. In addition, our results underscore the significance of ET acting as a central node in regulating mir1 expression to different feeding guilds of insect herbivores. PMID:26253737

  7. Can transgenic maize affect soil microbial communities?

    PubMed

    Mulder, Christian; Wouterse, Marja; Raubuch, Markus; Roelofs, Willem; Rutgers, Michiel

    2006-09-29

    The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their cells. Litter placement is known for its strong influence on the soil decomposer communities. The effects of the addition of crop residues on respiration and catabolic activities of the bacterial community were examined in microcosm experiments. Four cultivars of Zea mays L. of two different isolines (each one including the conventional crop and its Bacillus thuringiensis cultivar) and one control of bulk soil were included in the experimental design. The growth models suggest a dichotomy between soils amended with either conventional or transgenic maize residues. The Cry1Ab protein appeared to influence the composition of the microbial community. The highly enhanced soil respiration observed during the first 72 h after the addition of Bt-maize residues can be interpreted as being related to the presence of the transgenic crop residues. This result was confirmed by agar plate counting, as the averages of the colony-forming units of soils in conventional treatments were about one-third of those treated with transgenic straw. Furthermore, the addition of Bt-maize appeared to induce increased microbial consumption of carbohydrates in BIOLOG EcoPlates. Three weeks after the addition of maize residues to the soils, no differences between the consumption rate of specific chemical guilds by bacteria in soils amended with transgenic maize and bacteria in soils amended with conventional maize were detectable. Reaped crop residues, comparable to post-harvest maize straw (a common practice in current agriculture), rapidly influence the soil bacterial cells at a functional level. Overall, these data support the existence of short

  8. Maize transpiration in response to meteorological conditions

    NASA Astrophysics Data System (ADS)

    Klimešová, Jana; Stŕedová, Hana; Stŕeda, Tomáš

    2013-09-01

    Differences in transpiration of maize (Zea mays L.) plants in four soil moisture regimes were quantified in a pot experiment. The transpiration was measured by the "Stem Heat Balance" method. The dependence of transpiration on air temperature, air humidity, global solar radiation, soil moisture, wind speed and leaf surface temperature were quantified. Significant relationships among transpiration, global radiation and air temperature (in the first vegetation period in the drought non-stressed variant, r = 0.881**, r = 0.934**) were found. Conclusive dependence of transpiration on leaf temperature (r = 0.820**) and wind speed (r = 0.710**) was found. Transpiration was significantly influenced by soil moisture (r = 0.395**, r = 0.528**) under moderate and severe drought stress. The dependence of transpiration on meteorological factors decreased with increasing deficiency of water. Correlation between transpiration and plant dry matter weight (r = 0.997**), plant height (r = 0.973**) and weight of corn cob (r = 0.987**) was found. The results of instrumental measuring of field crops transpiration under diverse moisture conditions at a concurrent monitoring of the meteorological elements spectra are rather unique. These results will be utilized in the effort to make calculations of the evapotranspiration in computing models more accurate.

  9. Genome-Wide Association Mapping for Yield and Other Agronomic Traits in an Elite Breeding Population of Tropical Rice (Oryza sativa)

    PubMed Central

    Lalusin, Antonio; Borromeo, Teresita; Gregorio, Glenn; Hernandez, Jose; Virk, Parminder; Collard, Bertrand; McCouch, Susan R.

    2015-01-01

    Genome-wide association mapping studies (GWAS) are frequently used to detect QTL in diverse collections of crop germplasm, based on historic recombination events and linkage disequilibrium across the genome. Generally, diversity panels genotyped with high density SNP panels are utilized in order to assay a wide range of alleles and haplotypes and to monitor recombination breakpoints across the genome. By contrast, GWAS have not generally been performed in breeding populations. In this study we performed association mapping for 19 agronomic traits including yield and yield components in a breeding population of elite irrigated tropical rice breeding lines so that the results would be more directly applicable to breeding than those from a diversity panel. The population was genotyped with 71,710 SNPs using genotyping-by-sequencing (GBS), and GWAS performed with the explicit goal of expediting selection in the breeding program. Using this breeding panel we identified 52 QTL for 11 agronomic traits, including large effect QTLs for flowering time and grain length/grain width/grain-length-breadth ratio. We also identified haplotypes that can be used to select plants in our population for short stature (plant height), early flowering time, and high yield, and thus demonstrate the utility of association mapping in breeding populations for informing breeding decisions. We conclude by exploring how the newly identified significant SNPs and insights into the genetic architecture of these quantitative traits can be leveraged to build genomic-assisted selection models. PMID:25785447

  10. Genome-wide association mapping for yield and other agronomic traits in an elite breeding population of tropical rice (Oryza sativa).

    PubMed

    Begum, Hasina; Spindel, Jennifer E; Lalusin, Antonio; Borromeo, Teresita; Gregorio, Glenn; Hernandez, Jose; Virk, Parminder; Collard, Bertrand; McCouch, Susan R

    2015-01-01

    Genome-wide association mapping studies (GWAS) are frequently used to detect QTL in diverse collections of crop germplasm, based on historic recombination events and linkage disequilibrium across the genome. Generally, diversity panels genotyped with high density SNP panels are utilized in order to assay a wide range of alleles and haplotypes and to monitor recombination breakpoints across the genome. By contrast, GWAS have not generally been performed in breeding populations. In this study we performed association mapping for 19 agronomic traits including yield and yield components in a breeding population of elite irrigated tropical rice breeding lines so that the results would be more directly applicable to breeding than those from a diversity panel. The population was genotyped with 71,710 SNPs using genotyping-by-sequencing (GBS), and GWAS performed with the explicit goal of expediting selection in the breeding program. Using this breeding panel we identified 52 QTL for 11 agronomic traits, including large effect QTLs for flowering time and grain length/grain width/grain-length-breadth ratio. We also identified haplotypes that can be used to select plants in our population for short stature (plant height), early flowering time, and high yield, and thus demonstrate the utility of association mapping in breeding populations for informing breeding decisions. We conclude by exploring how the newly identified significant SNPs and insights into the genetic architecture of these quantitative traits can be leveraged to build genomic-assisted selection models.

  11. Climate Change and Maize Yield in Iowa

    PubMed Central

    Xu, Hong; Twine, Tracy E.; Girvetz, Evan

    2016-01-01

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10–20% by the end of the 21st century. PMID:27219116

  12. Climate change and maize yield in Iowa

    DOE PAGES

    Xu, Hong; Twine, Tracy E.; Girvetz, Evan

    2016-05-24

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output frommore » six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Lastly, our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century.« less

  13. Climate Change and Maize Yield in Iowa.

    PubMed

    Xu, Hong; Twine, Tracy E; Girvetz, Evan

    2016-01-01

    Climate is changing across the world, including the major maize-growing state of Iowa in the USA. To maintain crop yields, farmers will need a suite of adaptation strategies, and choice of strategy will depend on how the local to regional climate is expected to change. Here we predict how maize yield might change through the 21st century as compared with late 20th century yields across Iowa, USA, a region representing ideal climate and soils for maize production that contributes substantially to the global maize economy. To account for climate model uncertainty, we drive a dynamic ecosystem model with output from six climate models and two future climate forcing scenarios. Despite a wide range in the predicted amount of warming and change to summer precipitation, all simulations predict a decrease in maize yields from late 20th century to middle and late 21st century ranging from 15% to 50%. Linear regression of all models predicts a 6% state-averaged yield decrease for every 1°C increase in warm season average air temperature. When the influence of moisture stress on crop growth is removed from the model, yield decreases either remain the same or are reduced, depending on predicted changes in warm season precipitation. Our results suggest that even if maize were to receive all the water it needed, under the strongest climate forcing scenario yields will decline by 10-20% by the end of the 21st century.

  14. [Numerical taxonomy of agronomic trait in cultivated Lonicera japonica].

    PubMed

    Zhang, Shan-Shan; Huang, Lu-Qi; Yuan, Yuan; Chen, Ping

    2014-04-01

    Sixty-three morphological traits from 743 specimens of the 41 taxa within the cultivated Lonicera japonica were observed and measured, such as the height of plants, the length of leaf, the width of leaf, the length of anther, the alabastrum's number of one branch, the color of alabastrum and so on. A numerical taxonomy is presented by using the cluster analysis, principal components analysis (PCA) and factor analysis. Sixteen of 63 characters were screened by means of PCA and used for cluster analysis of 41 taxa with the method of Ward linkage and average euclidean distance. The cluster analysis showed that the 41 taxa could be divided into 5 groups when the Euclidean distance coefficient was 11.84. The factor analysis indicated that the shape of leaf, color of alabastrum, the pilosity and color of twiggery were of significance for the cultivated L. japonica classification. The results of this study will be a base for the core collection and breeding of L. japonica.

  15. Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

    NASA Astrophysics Data System (ADS)

    De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

    2015-04-01

    The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. In addition, biochars offer a simple, sustainable tool for managing organic wastes and to produce added value products. Numerous research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients and by providing other services such as improving soil physical and biological properties [1]. However, the effectiveness of biochar in enhancing plant fertility is a function of soil type, climate, and type of crop [2] but also of the biochar properties. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will not negatively affect soil health and productivity. The major goals of this research were: i) understanding how the properties of 5 different biochars produced by using different feedstock and pyrolysis conditions are related to their agronomic response, and ii) assessing the agronomic effect of biochar amendment under field conditions of a typical Mediterranean non-irrigated plantation. Four of the used biochars were produced by pyrolysis from wood (2), paper sludge (1) and sewage sludge (1), at temperatures up to 620 °C. The fifth biochar was produced from old grapevine wood by applying the traditional kiln method. Biochars were analysed for elemental composition (C, H, N), pH, WHC and ash contents. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by 13C solid-state NMR spectroscopy. The FT-IR spectra indicated the presence of lignin residues in

  16. MaizeGDB update: New tools, data, and interface for the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, ...

  17. Expression of an anthranilate synthase from maize mutant bf-1 in maize line HiII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize mutant bf-1 was one of a series of maize mutants generated by radiation from the Bikini Atoll atomic bomb test in 1946. It is characterized by blue fluorescence in seedlings and anthers under ultraviolet illumination and by mutant plants giving off a characteristic grape-like odor due to the ...

  18. Expanding maize genetic resources with predomestication alleles: maize-teosinte introgression populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Teosinte (Zea mays ssp. parviglumis) has greater genetic diversity than maize inbreds and landraces (Z. mays ssp. mays). There are, however, limited genetic resources to efficiently evaluate and tap this diversity. To broaden resources for genetic diversity studies in maize, we developed and evaluat...

  19. Soil Water Holding Capacity Mitigates Downside Risk and Volatility in US Rainfed Maize: Time to Invest in Soil Organic Matter?

    PubMed

    Williams, Alwyn; Hunter, Mitchell C; Kammerer, Melanie; Kane, Daniel A; Jordan, Nicholas R; Mortensen, David A; Smith, Richard G; Snapp, Sieglinde; Davis, Adam S

    2016-01-01

    Yield stability is fundamental to global food security in the face of climate change, and better strategies are needed for buffering crop yields against increased weather variability. Regional- scale analyses of yield stability can support robust inferences about buffering strategies for widely-grown staple crops, but have not been accomplished. We present a novel analytical approach, synthesizing 2000-2014 data on weather and soil factors to quantify their impact on county-level maize yield stability in four US states that vary widely in these factors (Illinois, Michigan, Minnesota and Pennsylvania). Yield stability is quantified as both 'downside risk' (minimum yield potential, MYP) and 'volatility' (temporal yield variability). We show that excessive heat and drought decreased mean yields and yield stability, while higher precipitation increased stability. Soil water holding capacity strongly affected yield volatility in all four states, either directly (Minnesota and Pennsylvania) or indirectly, via its effects on MYP (Illinois and Michigan). We infer that factors contributing to soil water holding capacity can help buffer maize yields against variable weather. Given that soil water holding capacity responds (within limits) to agronomic management, our analysis highlights broadly relevant management strategies for buffering crop yields against climate variability, and informs region-specific strategies.

  20. Relationship between genetic parameters in maize (Zea mays) with seedling growth parameters under 40-100% soil moisture conditions.

    PubMed

    Muhammad, R W; Qayyum, A

    2013-10-18

    We estimated the association of genetic parameters with production characters in 64 maize (Zea mays) genotypes in a green house in soil with 40-100% moisture levels (percent of soil moisture capacity). To identify the major parameters that account for variation among the genotypes, we used single linkage cluster analysis and principle component analysis. Ten plant characters were measured. The first two, four, three, and again three components, with eigen values > 1 contributed 75.05, 80.11, 68.67, and 75.87% of the variability among the genotypes under the different moisture levels, i.e., 40, 60, 80, and 100%, respectively. Other principal components (3-10, 5-10, and 4-10) had eigen values less than 1. The highest estimates of heritability were found for root fresh weight, root volume (0.99), and shoot fresh weight (0.995) in 40% soil moisture. Values of genetic advance ranged from 23.4024 for SR at 40% soil moisture to 0.2538 for shoot dry weight in 60% soil moisture. The high magnitude of broad sense heritability provides evidence that these plant characters are under the control of additive genetic effects. This indicates that selection should lead to fast genetic improvement of the material. The superior agronomic types that we identified may be exploited for genetic potential to improve yield potential of the maize crop.

  1. Soil Water Holding Capacity Mitigates Downside Risk and Volatility in US Rainfed Maize: Time to Invest in Soil Organic Matter?

    PubMed

    Williams, Alwyn; Hunter, Mitchell C; Kammerer, Melanie; Kane, Daniel A; Jordan, Nicholas R; Mortensen, David A; Smith, Richard G; Snapp, Sieglinde; Davis, Adam S

    2016-01-01

    Yield stability is fundamental to global food security in the face of climate change, and better strategies are needed for buffering crop yields against increased weather variability. Regional- scale analyses of yield stability can support robust inferences about buffering strategies for widely-grown staple crops, but have not been accomplished. We present a novel analytical approach, synthesizing 2000-2014 data on weather and soil factors to quantify their impact on county-level maize yield stability in four US states that vary widely in these factors (Illinois, Michigan, Minnesota and Pennsylvania). Yield stability is quantified as both 'downside risk' (minimum yield potential, MYP) and 'volatility' (temporal yield variability). We show that excessive heat and drought decreased mean yields and yield stability, while higher precipitation increased stability. Soil water holding capacity strongly affected yield volatility in all four states, either directly (Minnesota and Pennsylvania) or indirectly, via its effects on MYP (Illinois and Michigan). We infer that factors contributing to soil water holding capacity can help buffer maize yields against variable weather. Given that soil water holding capacity responds (within limits) to agronomic management, our analysis highlights broadly relevant management strategies for buffering crop yields against climate variability, and informs region-specific strategies. PMID:27560666

  2. Soil Water Holding Capacity Mitigates Downside Risk and Volatility in US Rainfed Maize: Time to Invest in Soil Organic Matter?

    PubMed Central

    Williams, Alwyn; Hunter, Mitchell C.; Kammerer, Melanie; Kane, Daniel A.; Jordan, Nicholas R.; Mortensen, David A.; Smith, Richard G.; Snapp, Sieglinde

    2016-01-01

    Yield stability is fundamental to global food security in the face of climate change, and better strategies are needed for buffering crop yields against increased weather variability. Regional- scale analyses of yield stability can support robust inferences about buffering strategies for widely-grown staple crops, but have not been accomplished. We present a novel analytical approach, synthesizing 2000–2014 data on weather and soil factors to quantify their impact on county-level maize yield stability in four US states that vary widely in these factors (Illinois, Michigan, Minnesota and Pennsylvania). Yield stability is quantified as both ‘downside risk’ (minimum yield potential, MYP) and ‘volatility’ (temporal yield variability). We show that excessive heat and drought decreased mean yields and yield stability, while higher precipitation increased stability. Soil water holding capacity strongly affected yield volatility in all four states, either directly (Minnesota and Pennsylvania) or indirectly, via its effects on MYP (Illinois and Michigan). We infer that factors contributing to soil water holding capacity can help buffer maize yields against variable weather. Given that soil water holding capacity responds (within limits) to agronomic management, our analysis highlights broadly relevant management strategies for buffering crop yields against climate variability, and informs region-specific strategies. PMID:27560666

  3. Chlortetracycline detoxification in maize via induction of glutathione S-transferases after antibiotic exposure.

    PubMed

    Farkas, Michael H; Berry, James O; Aga, Diana S

    2007-02-15

    Soil contamination with nonmetabolized antibiotics is an emerging environmental concern, especially on agricultural croplands that receive animal manure as fertilizer. In this study, phytotoxicity of chlortetracycline (CTC) antibiotics on pinto beans (Phaseolus vulgaris) and maize (Zea mays) was investigated under controlled conditions. When grown in CTC-treated soil, a significant increase in the activities of the plant stress proteins glutathione S-transferases (GST) and peroxidases (POX) were observed in maize plants, but not in pinto beans. In vitro conjugation reactions demonstrated that the induced GST in maize catalyzed the conjugation of glutathione (GSH) with CTC, producing stable conjugates that were structurally characterized using liquid chromatography/mass spectrometry. The antibiotic-induced GST produced CTC-glutathione conjugate at relative concentrations 2-fold higher than that produced by constitutively expressed GST extracted from untreated maize. On the other hand, GST extracted from pinto beans (both treated and untreated) did not efficiently catalyze glutathione conjugation with CTC. These results suggest that maize is able to detoxify chlortetracycline via the glutathione pathway, whereas pinto beans cannot. This may explain the observed stunted growth of pinto beans after antibiotic treatment. This study demonstrates the importance of plant uptake in determining the fate of antibiotics in soil and their potential phytotoxicity to susceptible plants. PMID:17593756

  4. Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots.

    PubMed

    Pereira, G S; Camargos, R B; Balestre, M; Von Pinho, R G; C Melo, W M

    2015-09-21

    Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation.

  5. Impact of Bt maize pollen (MON810) on lepidopteran larvae living on accompanying weeds.

    PubMed

    Gathmann, Achim; Wirooks, Ludger; Hothorn, Ludwig A; Bartsch, Detlef; Schuphan, Ingolf

    2006-08-01

    Environmental risks of Bt maize, particularly pollen drift from Bt maize, were assessed for nontarget lepidopteran larvae in maize field margins. In our experimental approach, we carried out 3-year field trials on 6 ha total. Three treatments were used in a randomized block design with eight replications resulting in 24 plots: (i) near-isogenic control variety without insecticide (control), (ii) near-isogenic control variety with chemical insecticide (Baytroid) and (iii) Bt maize expressing the recombinant toxin. We established a weed strip (20 x 1 m) in every plot consisting of a Chenopodium album (goosefoot)/Sinapis alba (mustard) mixture. In these strips we measured diversity and abundance of lepidopteran larvae during maize bloom and pollen shed. C. album hosted five species but all in very low densities; therefore data were not suitable for statistical analysis. S. alba hosted nine species in total. Most abundant were Plutella xylostella and Pieris rapae. For these species no differences were detected between the Bt treatment and the control, but the chemical insecticide treatment reduced larval abundance significantly. Conclusions regarding experimental methodology and results are discussed in regard to environmental risk assessment and monitoring of genetically modified organisms. PMID:16842436

  6. Monoclonal antibody-based serological methods for maize chlorotic mottle virus detection in China*

    PubMed Central

    Wu, Jian-xiang; Wang, Qiang; Liu, Huan; Qian, Ya-juan; Xie, Yan; Zhou, Xue-ping

    2013-01-01

    Maize chlorotic mottle virus (MCMV) infects maize plants and causes significant losses in corn production worldwide. In this study, purified MCMV particles were used as the immunogen to produce monoclonal antibodies (MAbs) and polyclonal antibodies (PAbs). Four murine MAbs (4B8, 8C11, 6F4, and 9G1) against MCMV were obtained through the hybridoma technology. The triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA), dot-immunobinding assay (DIBA), and immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) using the MAb 4B8 were then developed for sensitive, specific, and rapid detection of MCMV in fields. MCMV could be detected in infected leaf crude extracts at dilutions of 1:327 680, 1:64 000, and 1:3 276 800 (w/v, g/ml) by TAS-ELISA, DIBA, and IC-RT-PCR, respectively. One hundred and sixty-one maize field samples showing virus-like symptoms and sixty-nine symptomless maize field samples from ten different provinces of China were collected and screened for the presence of MCMV using the established serological methods. A phylogenetic tree was constructed based on the full length CP genes and Chinese MCMV isolates formed one branch with Thailand isolates. The detection results demonstrated that MCMV is one of most prevalent viruses infecting maize in the Yunnan and Sichuan provinces of China. PMID:23825140

  7. Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize.

    PubMed

    Meissle, Michael; Zünd, Jan; Waldburger, Mario; Romeis, Jörg

    2014-01-01

    Maize (Zea mays) pollen is highly nutritious and can be used by predatory arthropods to supplement or replace a carnivorous diet. We demonstrate that maize pollen can be utilized by larvae of the green lacewing, Chrysoperla carnea (Neuroptera: Chrysopidae) under laboratory conditions. Complete development on maize pollen was not possible, but 25% of neonates reached the third instar. When only one instar was fed with pollen and the other two instars with eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), 58-87% of the larvae reached the pupal stage. The experiments included pollen produced by nine cultivars: three genetically modified (GM) cultivars expressing the Bacillus thuringiensis proteins Cry1Ab or Cry3Bb1, their corresponding non-transformed near-isolines, and three conventional cultivars. Maize cultivars were grown in two batches in a glasshouse. Their pollen differed by up to 59% in total protein content, 25% in C:N ratio, and 14% in grain diameter, but the differences were inconsistent and depended on the batch. Lacewing performance was not affected by maize cultivar. For environmental risk assessment of GM plants, in planta studies must consider the variability among conventional cultivars, individual plants, batches, and environmental conditions when evaluating the ecological significance of differences observed between GM and near-isolines. PMID:25082074

  8. Comparative Proteomic Analyses Provide New Insights into Low Phosphorus Stress Responses in Maize Leaves

    PubMed Central

    Zhang, Kewei; Liu, Hanhan; Tao, Peilin; Chen, Huan

    2014-01-01

    Phosphorus deficiency limits plant growth and development. To better understand the mechanisms behind how maize responds to phosphate stress, we compared the proteome analysis results of two groups of maize leaves that were treated separately with 1,000 µM (control, +P) and 5 µM of KH2PO4 (intervention group, −P) for 25 days. In total, 1,342 protein spots were detected on 2-DE maps and 15.43% had changed (P<0.05; ≥1.5-fold) significantly in quantity between the +P and −P groups. These proteins are involved in several major metabolic pathways, including photosynthesis, carbohydrate metabolism, energy metabolism, secondary metabolism, signal transduction, protein synthesis, cell rescue and cell defense and virulence. The results showed that the reduction in photosynthesis under low phosphorus treatment was due to the down-regulation of the proteins involved in CO2 enrichment, the Calvin cycle and the electron transport system. Electron transport and photosynthesis restrictions resulted in a large accumulation of peroxides. Maize has developed many different reactive oxygen species (ROS) scavenging mechanisms to cope with low phosphorus stress, including up-regulating its antioxidant content and antioxidase activity. After being subjected to phosphorus stress over a long period, maize may increase its internal phosphorus utilization efficiency by altering photorespiration, starch synthesis and lipid composition. These results provide important information about how maize responds to low phosphorus stress. PMID:24858307

  9. Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots.

    PubMed

    Pereira, G S; Camargos, R B; Balestre, M; Von Pinho, R G; C Melo, W M

    2015-01-01

    Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation. PMID:26400335

  10. Priming maize resistance by its neighbors: activating 1,4-benzoxazine-3-ones synthesis and defense gene expression to alleviate leaf disease

    PubMed Central

    Ding, Xupo; Yang, Min; Huang, Huichuan; Chuan, Youcong; He, Xiahong; Li, Chengyun; Zhu, Youyong; Zhu, Shusheng

    2015-01-01

    Plant disease can be effectively suppressed in intercropping systems. Our previous study demonstrated that neighboring maize plants can restrict the spread of soil-borne pathogens of pepper plants by secreting defense compounds into the soil. However, whether maize plant can receive benefits from its neighboring pepper plants in an intercropping system is little attention. We examined the effects of maize roots treated with elicitors from the pepper pathogen Phytophthora capsici and pepper root exudates on the synthesis of 1,4-benzoxazine-3-ones (BXs), the expression of defense-related genes in maize, and their ability to alleviate the severity of southern corn leaf blight (SCLB) caused by Bipolaris maydis. We found that SCLB was significantly reduced after the above treatments. The contents of 1,4-benzoxazine-3-ones (BXs: DIBOA, DIMBOA, and MBOA) and the expression levels of BX synthesis and defense genes in maize roots and shoots were up-regulated. DIMBOA and MBOA effectively inhibited the mycelium growth of Bipolaris maydis at physiological concentrations in maize shoots. Further studies suggested that the defense related pathways or genes in maize roots and shoots were activated by elicitors from the P. capsici or pepper root exudates. In conclusion, maize increased the levels of BXs and defense gene expression both in roots and shoots after being triggered by root exudates and pathogen from neighboring pepper plants, eventually enhancing its resistance. PMID:26528303

  11. Concentration and dissipation of chlorantraniliprole and thiamethoxam residues in maize straw, maize, and soil.

    PubMed

    He, Min; Song, Dan; Jia, Hong C; Zheng, Yongquan

    2016-09-01

    To study the dissipation rates and final residual levels of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil, two independent field trials were conducted during the 2014 cropping season in Beijing and Anhui Provinces of China. A 40% wettable powder (20% chlorantraniliprole + 20% thiamethoxam) was sprayed onto maize straw and soil at an application rate of 118 g of active ingredient per hectare (g a.i.ha(-1)). The residual concentrations were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. The chlorantraniliprole half-lives in maize straw and soil were 9.0-10.8 and 9.5-21.7 days, respectively. The thiamethoxam half-lives in maize straw and soil were 8.4-9.8 and 4.3-11.7 days, respectively. The final residues of chlorantraniliprole and thiamethoxam in maize straw, maize, and soil were measured after the pesticides had been sprayed two and three times with an interval of 7 days using 1 and 1.5 times the recommended rate (72 g a.i. ha(-1) and 108 g a.i. ha(-1), respectively). Representative maize straw, maize, and soil samples were collected after the last treatment at pre-harvest intervals of 7, 14, and 28 days. The chlorantraniliprole residue was below 0.01 mg kg(-1) in maize, between 0.01 and 0.31 mg kg(-1) in maize straw, and between 0.03 and 1.91 mg kg(-1) in soil. The thiamethoxam residue concentrations in maize, maize straw, and soil were <0.01, <0.01, and 0.01-0.03 mg kg(-1), respectively. The final pesticide residues on maize were lower than the maximum residue limit (MRL) of 0.02 mg kg(-1) after a 14-day pre-harvest interval. Therefore, a dosage of 72 g a.i. ha(-1) was recommended, as it can be considered safe to human beings and animals. PMID:27192406

  12. Effect of tempe-yellow maize porridge and milk-yellow maize porridge on growth rate, diarrhoea and duration of rehabilitation of malnourished children.

    PubMed

    Kalavi, F N; Muroki, N M; Omwega, A M; Mwadime, R K

    1996-07-01

    The diet for 117 protein-energy-malnourished children admitted into the Mbooni Family Life Training Centre between November 1992 and March 1993, was supplemented with either tempe-yellow maize porridge (TYMP) or milk-yellow maize porridge (MYMP). Fifty-six malnourished children had their diet supplemented with TYMP. Another group of 61 children had theirs supplemented with MYMP. The growth rate (weight gain), duration of diarrhoeal episodes and rehabilitation period for each child was recorded and a comparison made between the two dietary groups. The TYMP group achieved a significantly (p < 0.05) higher growth rate (5.2 gm/kg body weight/day) compared to the MYMP whose growth rate was 2.2 gm/kg body weight/day. The mean daily protein and caloric consumption (per kg body weight) by the children in both groups (at 3.4 gm of proteins and 83 calories for the MYMP group and 3.9 gm of protein and 101 calories for the TYMP group) were not significantly different. The duration of diarrhoeal episodes for the MYMP group was significantly (P < 0.05) longer (4.6 diarrhoea days) than that of the TYMP group whose diarrhoeal episodes lasted 0.7 diarrhoea days. The rehabilitation period for the TYMP group (15 days) was significantly (p > 0.05) lower than that for the MYMP group which was 20 days. Furthermore, the cost of supplementing the diet for each child with the tempe-yellow maize porridge (KSh. 1625) was approximately 25% lower than that of supplementing it with milk-yellow maize porridge which was KSh. 2060. These results suggest that it may be more beneficial in terms of duration of both diarrhoeal episodes and rehabilitation period and overall institutional cost if malnourished children's diets are supplemented with tempe-yellow maize porridge.

  13. [Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].

    PubMed

    Yong, Tai-Wen; Liu, Xiao-Ming; Wen-Yu, Liu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

    2014-02-01

    A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean

  14. Transcriptome dynamics of developing maize leaves and genomewide prediction of cis elements and their cognate transcription factors

    PubMed Central

    Yu, Chun-Ping; Chen, Sean Chun-Chang; Chang, Yao-Ming; Liu, Wen-Yu; Lin, Hsin-Hung; Lin, Jinn-Jy; Chen, Hsiang June; Lu, Yu-Ju; Wu, Yi-Hsuan; Lu, Mei-Yeh Jade; Lu, Chen-Hua; Shih, Arthur Chun-Chieh; Ku, Maurice Sun-Ben; Shiu, Shin-Han; Wu, Shu-Hsing; Li, Wen-Hsiung

    2015-01-01

    Maize is a major crop and a model plant for studying C4 photosynthesis and leaf development. However, a genomewide regulatory network of leaf development is not yet available. This knowledge is useful for developing C3 crops to perform C4 photosynthesis for enhanced yields. Here, using 22 transcriptomes of developing maize leaves from dry seeds to 192 h post imbibition, we studied gene up- and down-regulation and functional transition during leaf development and inferred sets of strongly coexpressed genes. More significantly, we developed a method to predict transcription factor binding sites (TFBSs) and their cognate transcription factors (TFs) using genomic sequence and transcriptomic data. The method requires not only evolutionary conservation of candidate TFBSs and sets of strongly coexpressed genes but also that the genes in a gene set share the same Gene Ontology term so that they are involved in the same biological function. In addition, we developed another method to predict maize TF–TFBS pairs using known TF–TFBS pairs in Arabidopsis or rice. From these efforts, we predicted 1,340 novel TFBSs and 253 new TF–TFBS pairs in the maize genome, far exceeding the 30 TF–TFBS pairs currently known in maize. In most cases studied by both methods, the two methods gave similar predictions. In vitro tests of 12 predicted TF–TFBS interactions showed that our methods perform well. Our study has significantly expanded our knowledge on the regulatory network involved in maize leaf development. PMID:25918418

  15. Modeling bulk canopy resistance from climatic variables for predicting hourly evapotranspiration of maize and buckwheat

    NASA Astrophysics Data System (ADS)

    Yan, Haofang; Shi, Haibin; Hiroki, Oue; Zhang, Chuan; Xue, Zhu; Cai, Bin; Wang, Guoqing

    2015-06-01

    This study presents models for predicting hourly canopy resistance ( r c) and evapotranspiration (ETc) based on Penman-Monteith approach. The micrometeorological data and ET c were observed during maize and buckwheat growing seasons in 2006 and 2009 in China and Japan, respectively. The proposed models of r c were developed by a climatic resistance ( r *) that depends on climatic variables. Non-linear relationships between r c and r * were applied. The measured ETc using Bowen ratio energy balance method was applied for model validation. The statistical analysis showed that there were no significant differences between predicted ETc by proposed models and measured ETc for both maize and buckwheat crops. The model for predicting ETc at maize field showed better performance than predicting ETc at buckwheat field, the coefficients of determination were 0.92 and 0.84, respectively. The study provided an easy way for the application of Penman-Monteith equation with only general available meteorological database.

  16. CONTROL OF DIABROTICA VIRGIFERA VIRGIFERA LE CONTE IN MAIZE SEED TREATMENT.

    PubMed

    Inđić, D; Vuković, S; Kljajić, P; Gvozdenac, S; Tanasković, S; Andrić, G

    2014-01-01

    During the last decade of XX century, Diabrotica virgifera virgifera Le Conte became an important introduced harmful species in maize production in the northern Serbia region. The aim of this work was to assess the efficacy of imidacloprid based insecticides formulated for seed treatment in the control of D. v. virgifera. Experiments were set at two localities (Čurug--two-year maize culturing; Bečej--four-year maize culturing) in 2013, according to OEPP (PP 1/212(1) 2004) method. Imidacloprid based insecticide (600 g a.i./L) was applied at rates 0.36; 0.55; 0,7 and 0.8 L/100 kg of maize seeds (hybrids NS 5041 and NS 640 Ultra). The degree of maize root damage was determined according to scale 1-6 (http://www.ent.iastate.edu/-pest/rootworm/nodeinjury/nodeinjury.htm). A number of damaged plants was also registered and expressed in percents, as well as the development of adventitious roots. Significance of differences between root damages and number of damaged plants between treatments was tested using ANOVA. Regardless on localities and applied rates, maize roots in treatments with imidacloprid were significantly less damaged by larvae D. v. virgifera (1.1-1.4) compared to the control (3.7-4.1). Also, a significant reduction in percent of damaged plants (5.0-20%) was registered compared to the control (90-97.5%). At both localities in treatments with imidacloprid adventitious roots were well developed in 60.5 to 91% of plants compared to the control were it was the case in 10-27.5% plants. It is important to emphasize that roots were significantly more developed in treated variants compared to the control. Based on the obtained results it can be concluded that imidacloprid, regardless on its future status and restraints/limitations in maize seed treatment, provided efficient protection of maize roots from D. v. virgifera larvae, even at rate twice lower (0.36) than recommended (0.8 L/100 kg seeds), which justifies the application of lower quantities of imidacloprid

  17. Unlocking the Genetic Diversity of Maize Landraces with Doubled Haploids Opens New Avenues for Breeding

    PubMed Central

    Strigens, Alexander; Schipprack, Wolfgang; Reif, Jochen C.; Melchinger, Albrecht E.

    2013-01-01

    Landraces are valuable genetic resources for broadening the genetic base of elite germplasm in maize. Extensive exploitation of landraces has been hampered by their genetic heterogeneity and heavy genetic load. These limitations may be overcome by the in-vivo doubled haploid (DH) technique. A set of 132 DH lines derived from three European landraces and 106 elite flint (EF) lines were genotyped for 56,110 single nucleotide polymorphism (SNP) markers and evaluated in field trials at five locations in Germany in 2010 for several agronomic traits. In addition, the landraces were compared with synthetic populations produced by intermating DH lines derived from the respective landrace. Our objectives were to (1) evaluate the phenotypic and molecular diversity captured within DH lines derived from European landraces, (2) assess the breeding potential (usefulness) of DH lines derived from landraces to broaden the genetic base of the EF germplasm, and (3) compare the performance of each landrace with the synthetic population produced from the respective DH lines. Large genotypic variances among DH lines derived from landraces allowed the identification of DH lines with grain yields comparable to those of EF lines. Selected DH lines may thus be introgressed into elite germplasm without impairing its yield level. Large genetic distances of the DH lines to the EF lines demonstrated the potential of DH lines derived from landraces to broaden the genetic base of the EF germplasm. The comparison of landraces with their respective synthetic population showed no yield improvement and no reduction of phenotypic diversity. Owing to the low population structure and rapid decrease of linkage disequilibrium within populations of DH lines derived from landraces, these would be an ideal tool for association mapping. Altogether, the DH technology opens new opportunities for characterizing and utilizing the genetic diversity present in gene bank accessions of maize. PMID:23451190

  18. Multiscale visualization of the structural and characteristic changes of sewage sludge biochar oriented towards potential agronomic and environmental implication

    PubMed Central

    Zhang, Jining; Lü, Fan; Zhang, Hua; Shao, Liming; Chen, Dezhen; He, Pinjing

    2015-01-01

    Sewage sludge biochars were obtained at different pyrolysis temperatures from 300°C to 900°C and their macro- and microscale properties were analyzed. The biochar's plant-available nutrients and humus-like substances in the water-extractable phase and fixed nutrients in the solid fraction were evaluated for their potential agronomic implications. FT-IR, Raman, XRD, XPS, and SEM techniques were used to investigate the chemical structure, functional groups, and microcrystal structure on the surface of the biochar. The results revealed minor chemical changes and dramatic mass loss in the biochar obtained at 300–500°C, whereas significant chemical changes in the biochar were obtained at 600–900°C. The concentrations of plant-available nutrients as well as fulvic- and humic-acid-like materials decreased in the biochar samples obtained at higher temperatures. These results implied that the biochar samples pyrolyzed at 300–500°C could be a direct nutrient source and used to neutralize alkaline soil. The surface area and porosity of the biochar samples increased with temperature, which increased their adsorption capacity. Rearrangement occurred at higher temperature 600–900°C, resulting in the biochar becoming increasingly polyaromatic and its graphite-like carbon becoming organized. PMID:25802185

  19. Agronomic properties of wastewater sludge biochar and bioavailability of metals in production of cherry tomato (Lycopersicon esculentum).

    PubMed

    Hossain, Mustafa K; Strezov, Vladimir; Chan, K Yin; Nelson, Peter F

    2010-02-01

    This work presents agronomic values of a biochar produced from wastewater sludge through pyrolysis at a temperature of 550 degrees C. In order to investigate and quantify effects of wastewater sludge biochar on soil quality, growth, yield and bioavailability of metals in cherry tomatoes, pot experiments were carried out in a temperature controlled environment and under four different treatments consisting of control soil, soil with biochar; soil with biochar and fertiliser, and soil with fertiliser only. The soil used was chromosol and the applied wastewater sludge biochar was 10tha(-1). The results showed that the application of biochar improves the production of cherry tomatoes by 64% above the control soil conditions. The ability of biochar to increase the yield was attributed to the combined effect of increased nutrient availability (P and N) and improved soil chemical conditions upon amendment. The yield of cherry tomato production was found to be at its maximum when biochar was applied in combination with the fertiliser. Application of biochar was also found to significantly increase the soil electrical conductivity as well as phosphorus and nitrogen contents. Bioavailability of metals present in the biochar was found to be below the Australian maximum permitted concentrations for food. PMID:20110103

  20. Multiscale visualization of the structural and characteristic changes of sewage sludge biochar oriented towards potential agronomic and environmental implication.

    PubMed

    Zhang, Jining; Lü, Fan; Zhang, Hua; Shao, Liming; Chen, Dezhen; He, Pinjing

    2015-01-01

    Sewage sludge biochars were obtained at different pyrolysis temperatures from 300°C to 900°C and their macro- and microscale properties were analyzed. The biochar's plant-available nutrients and humus-like substances in the water-extractable phase and fixed nutrients in the solid fraction were evaluated for their potential agronomic implications. FT-IR, Raman, XRD, XPS, and SEM techniques were used to investigate the chemical structure, functional groups, and microcrystal structure on the surface of the biochar. The results revealed minor chemical changes and dramatic mass loss in the biochar obtained at 300-500°C, whereas significant chemical changes in the biochar were obtained at 600-900°C. The concentrations of plant-available nutrients as well as fulvic- and humic-acid-like materials decreased in the biochar samples obtained at higher temperatures. These results implied that the biochar samples pyrolyzed at 300-500°C could be a direct nutrient source and used to neutralize alkaline soil. The surface area and porosity of the biochar samples increased with temperature, which increased their adsorption capacity. Rearrangement occurred at higher temperature 600-900°C, resulting in the biochar becoming increasingly polyaromatic and its graphite-like carbon becoming organized.

  1. Statistical analysis of agronomical factors and weather conditions influencing deoxynivalenol levels in oats in Scandinavia.

    PubMed

    Lindblad, M; Börjesson, T; Hietaniemi, V; Elen, O

    2012-01-01

    The relationship between weather data and agronomical factors and deoxynivalenol (DON) levels in oats was examined with the aim of developing a predictive model. Data were collected from a total of 674 fields during periods of up to 10 years in Finland, Norway and Sweden, and included DON levels in the harvested oats crop, agronomical factors and weather data. The results show that there was a large regional variation in DON levels, with higher levels in one region in Norway compared with other regions in Norway, Finland and Sweden. In this region the median DON level was 1000 ng g⁻¹ and the regulatory limit for human consumption (1750 ng g⁻¹) was exceeded in 28% of the samples. In other regions the median DON levels ranged from 75 to 270 ng g⁻¹, and DON levels exceeded 1750 ng g⁻¹ in 3-8% of the samples. Including more variables than region in a multiple regression model only increased the adjusted coefficient of determination from 0.17 to 0.24, indicating that very little of the variation in DON levels could be explained by weather data or agronomical factors. Thus, it was not possible to predict DON levels based on the variables included in this study. Further studies are needed to solve this problem. Apparently the infection and/or growth of DON producing Fusarium species are promoted in certain regions. One possibility may be to study the species distribution of fungal communities and their changes during the oats cultivation period in more detail.

  2. An agronomic field-scale sensor network for monitoring soil water and temperature variation

    NASA Astrophysics Data System (ADS)

    Brown, D. J.; Gasch, C.; Brooks, E. S.; Huggins, D. R.; Campbell, C. S.; Cobos, D. R.

    2014-12-01

    Environmental sensor networks have been deployed in a variety of contexts to monitor plant, air, water and soil properties. To date, there have been relatively few such networks deployed to monitor dynamic soil properties in cropped fields. Here we report on experience with a distributed soil sensor network that has been deployed for seven years in a research farm with ongoing agronomic field operations. The Washington State University R. J. Cook Agronomy Farm (CAF), Pullman, WA, USA has recently been designated a United States Department of Agriculture (USDA) Long-Term Agro-Ecosystem Research (LTAR) site. In 2007, 12 geo-referenced locations at CAF were instrumented, then in 2009 this network was expended to 42 locations distributed across the 37-ha farm. At each of this locations, Decagon 5TE probes (Decagon Devices Inc., Pullman, WA, USA) were installed at five depths (30, 60, 90, 120, and 150 cm), with temperature and volumetric soil moisture content recorded hourly. Initially, data loggers were wirelessly connected to a data station that could be accessed through a cell connection, but due to the logistics of agronomic field operations, we later buried the dataloggers at each site and now periodically download data via local radio transmission. In this presentation, we share our experience with the installation, maintenance, calibration and data processing associated with an agronomic soil monitoring network. We also present highlights of data derived from this network, including seasonal fluctuations of soil temperature and volumetric water content at each depth, and how these measurements are influenced by crop type, soil properties, landscape position, and precipitation events.

  3. Transcriptional activity of transposable elements in maize

    PubMed Central

    2010-01-01

    Background Mobile genetic elements represent a high proportion of the Eukaryote genomes. In maize, 85% of genome is composed by transposable elements of several families. First step in transposable element life cycle is the synthesis of an RNA, but few is known about the regulation of transcription for most of the maize transposable element families. Maize is the plant from which more ESTs have been sequenced (more than two million) and the third species in total only after human and mice. This allowed us to analyze the transcriptional activity of the maize transposable elements based on EST databases. Results We have investigated the transcriptional activity of 56 families of transposable elements in different maize organs based on the systematic search of more than two million expressed sequence tags. At least 1.5% maize ESTs show sequence similarity with transposable elements. According to these data, the patterns of expression of each transposable element family is variable, even within the same class of elements. In general, transcriptional activity of the gypsy-like retrotransposons is higher compared to other classes. Transcriptional activity of several transposable elements is specially high in shoot apical meristem and sperm cells. Sequence comparisons between genomic and transcribed sequences suggest that only a few copies are transcriptionally active. Conclusions The use of powerful high-throughput sequencing methodologies allowed us to elucidate the extent and character of repetitive element transcription in maize cells. The finding that some families of transposable elements have a considerable transcriptional activity in some tissues suggests that, either transposition is more frequent than previously expected, or cells can control transposition at a post-transcriptional level. PMID:20973992

  4. Study Progress on Tissue Culture of Maize Mature Embryo

    NASA Astrophysics Data System (ADS)

    Wang, Hongzhen; Cheng, Jun; Cheng, Yanping; Zhou, Xioafu

    It has been paid more and more attention on maize tissue culture as it is a basic work in maize genetic transformation, especially huge breakthrough has been made in maize tissue culture utilizing mature embryos as explants in the recent years. This paper reviewed the study progress on maize tissue culture and plant regeneration utilizing mature embryos as explants from callus induction, subculture, plant regeneration and browning reduction and so on.

  5. Quantitative Field Testing Heterodera glycines from Metagenomic DNA Samples Isolated Directly from Soil under Agronomic Production

    PubMed Central

    Li, Yan; Lawrence, Gary W.; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P.

    2014-01-01

    A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production. The estimation of H. glycines quantity was determined in soil samples having other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil. PMID:24587100

  6. Agronomic characterization of the Argentina Indicator Region. [U.S. corn belt and Argentine pampas

    NASA Technical Reports Server (NTRS)

    Hicks, D. R. (Principal Investigator)

    1982-01-01

    An overview of the Argentina indicator region including information on topography, climate, soils and vegetation is presented followed by a regionalization of crop livestock land use. Corn/soybean production and exports as well as agricultural practices are discussed. Similarities and differences in the physical agronomic scene, crop livestock land use and agricultural practices between the U.S. corn belt and the Argentine pampa are considered. The Argentine agricultural economy is described. Crop calendars for the Argentina indicator region, an accompanying description, notes on crop-livestock zones, wheat production, field size, and agricultural problems and practices are included.

  7. Quantitative field testing Heterodera glycines from metagenomic DNA samples isolated directly from soil under agronomic production.

    PubMed

    Li, Yan; Lawrence, Gary W; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P

    2014-01-01

    A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene was developed. The procedure estimated the quantity of H. glycines from metagenomic DNA samples isolated directly from field soil under agronomic production. The estimation of H. glycines quantity was determined in soil samples having other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil.

  8. Conservation Agriculture Practices in Rainfed Uplands of India Improve Maize-Based System Productivity and Profitability.

    PubMed

    Pradhan, Aliza; Idol, Travis; Roul, Pravat K

    2016-01-01

    Traditional agriculture in rainfed uplands of India has been experiencing low agricultural productivity as the lands suffer from poor soil fertility, susceptibility to water erosion and other external pressures of development and climate change. A shift toward more sustainable cropping systems such as conservation agriculture production systems (CAPSs) may help in maintaining soil quality as well as improving crop production and farmer's net economic benefit. This research assessed the effects over 3 years (2011-2014) of reduced tillage, intercropping, and cover cropping practices customized for maize-based production systems in upland areas of Odisha, India. The study focused on crop yield, system productivity and profitability through maize equivalent yield and dominance analysis. Results showed that maize grain yield did not differ significantly over time or among CAPS treatments while cowpea yield was considered as an additional yield in intercropping systems. Mustard and horsegram grown in plots after maize cowpea intercropping recorded higher grain yields of 25 and 37%, respectively, as compared to those without intercropping. Overall, the full CAPS implementation, i.e., minimum tillage, maize-cowpea intercropping and mustard residue retention had significantly higher system productivity and net benefits than traditional farmer practices, i.e., conventional tillage, sole maize cropping, and no mustard residue retention. The dominance analysis demonstrated increasing benefits of combining conservation practices that exceeded thresholds for farmer adoption. Given the use of familiar crops and technologies and the magnitude of yield and income improvements, these types of CAPS should be acceptable and attractive for smallholder farmers in the area. This in turn should support a move toward sustainable intensification of crop production to meet future household income and nutritional needs. PMID:27471508

  9. Conservation Agriculture Practices in Rainfed Uplands of India Improve Maize-Based System Productivity and Profitability.

    PubMed

    Pradhan, Aliza; Idol, Travis; Roul, Pravat K

    2016-01-01

    Traditional agriculture in rainfed uplands of India has been experiencing low agricultural productivity as the lands suffer from poor soil fertility, susceptibility to water erosion and other external pressures of development and climate change. A shift toward more sustainable cropping systems such as conservation agriculture production systems (CAPSs) may help in maintaining soil quality as well as improving crop production and farmer's net economic benefit. This research assessed the effects over 3 years (2011-2014) of reduced tillage, intercropping, and cover cropping practices customized for maize-based production systems in upland areas of Odisha, India. The study focused on crop yield, system productivity and profitability through maize equivalent yield and dominance analysis. Results showed that maize grain yield did not differ significantly over time or among CAPS treatments while cowpea yield was considered as an additional yield in intercropping systems. Mustard and horsegram grown in plots after maize cowpea intercropping recorded higher grain yields of 25 and 37%, respectively, as compared to those without intercropping. Overall, the ful