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Sample records for agronomic significance maize

  1. Identifying genes of agronomic importance in maize by screening microsatellites for evidence of selection during domestication

    PubMed Central

    Vigouroux, Y.; McMullen, M.; Hittinger, C. T.; Houchins, K.; Schulz, L.; Kresovich, S.; Matsuoka, Y.; Doebley, J.

    2002-01-01

    Crop species experienced strong selective pressure directed at genes controlling traits of agronomic importance during their domestication and subsequent episodes of selective breeding. Consequently, these genes are expected to exhibit the signature of selection. We screened 501 maize genes for the signature of selection using microsatellites or simple sequence repeats (SSRs). We applied the Ewens–Watterson test, which can reveal deviations from a neutral-equilibrium model, as well as two nonequilibrium tests that incorporate the domestication bottleneck. We investigated two classes of SSRs: those known to be polymorphic in maize (Class I) and those previously classified as monomorphic in maize (Class II). Fifteen SSRs exhibited some evidence for selection in maize and 10 showed evidence under stringent criteria. The genes containing nonneutral SSRs are candidates for agronomically important genes. Because demographic factors can bias our tests, further independent tests of these candidates are necessary. We applied such an additional test to one candidate, which encodes a MADS box transcriptional regulator, and confirmed that this gene experienced a selective sweep during maize domestication. Genomic scans for the signature of selection offer a means of identifying new genes of agronomic importance even when gene function and the phenotype of interest are unknown. PMID:12105270

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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. PMID:26214429

  7. Determining the Most Important Physiological and Agronomic Traits Contributing to Maize Grain Yield through Machine Learning Algorithms: A New Avenue in Intelligent Agriculture

    PubMed Central

    Shekoofa, Avat; Emam, Yahya; Shekoufa, Navid; Ebrahimi, Mansour; Ebrahimie, Esmaeil

    2014-01-01

    Prediction is an attempt to accurately forecast the outcome of a specific situation while using input information obtained from a set of variables that potentially describe the situation. They can be used to project physiological and agronomic processes; regarding this fact, agronomic traits such as yield can be affected by a large number of variables. In this study, we analyzed a large number of physiological and agronomic traits by screening, clustering, and decision tree models to select the most relevant factors for the prospect of accurately increasing maize grain yield. Decision tree models (with nearly the same performance evaluation) were the most useful tools in understanding the underlying relationships in physiological and agronomic features for selecting the most important and relevant traits (sowing date-location, kernel number per ear, maximum water content, kernel weight, and season duration) corresponding to the maize grain yield. In particular, decision tree generated by C&RT algorithm was the best model for yield prediction based on physiological and agronomical traits which can be extensively employed in future breeding programs. No significant differences in the decision tree models were found when feature selection filtering on data were used, but positive feature selection effect observed in clustering models. Finally, the results showed that the proposed model techniques are useful tools for crop physiologists to search through large datasets seeking patterns for the physiological and agronomic factors, and may assist the selection of the most important traits for the individual site and field. In particular, decision tree models are method of choice with the capability of illustrating different pathways of yield increase in breeding programs, governed by their hierarchy structure of feature ranking as well as pattern discovery via various combinations of features. PMID:24830330

  8. Maize yield gaps caused by non-controllable, agronomic, and socioeconomic factors in a changing climate of Northeast China.

    PubMed

    Liu, Zhijuan; Yang, Xiaoguang; Lin, Xiaomao; Hubbard, Kenneth G; Lv, Shuo; Wang, Jing

    2016-01-15

    Closing the gap between current and potential yields is one means of increasing agricultural production to feed the globally increasing population. Therefore, investigation of the geographic patterns, trends and causes of crop yield gaps is essential to identifying where yields might be increased and quantifying the contributions of yield-limiting factors that may provide us potentials to enhance crop productivity. In this study, the changes in potential yields, attainable yields, potential farmers' yields, and actual farmers' yields during the past five decades in Northeast China (NEC) were investigated. Additionally the yield gaps caused by non-controllable, agronomic, and socioeconomic factors were determined. Over the period 1961 to 2010 the estimated regional area-weighted mean maize potential yield, attainable yield, and potential farmers' yield were approximately 12.3 t ha(-1), 11.5 t ha(-1), and 6.4 t ha(-1) which showed a decreasing tendency. The actual farmers' yield over NEC was 4.5 t ha(-1), and showed a tendency to increase (p<0.01) by 1.27 t ha(-1) per decade. The regional mean total yield gap (YGt), weighted by the area in each county dedicated to maize crop, was 64% of potential yield. Moreover, 8, 40, and 16% reductions in potential yields were due to non-controllable factors (YGI), agronomic factors (YGII), and socioeconomic factors (YGIII), respectively. Therefore, the exploitable yield gap, considered here as the difference between the potential yield and what one can expect considering non-controllable factors (i.e. YGt-YGI), of maize in NEC was about 56%. The regional area-weighted averages of YGt, and YGIII were found to have significant decreases of 11.0, and 10.7% per decade. At the time horizon 2010, the exploitable yield gaps were estimated to equal 36% of potential yield. This led to the conclusion that the yield gap could be deeply reduced by improving local agronomic management and controlling socioeconomic factors. PMID:26437349

  9. Genome-wide association analysis for non agronomic traits in maize under well-watered and water-stressed conditions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought is the most serious environmental stress facing maize production, and strongly threatens crop yields. Changes in agronomic traits in response to this stress have been extensively studied using biparental mapping populations and inbred lines, but little is known about the related genes and un...

  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. QuickBird Satellite and Ground-based Multispectral Data Correlations with Agronomic Parameters of Irrigated Maize Grown in Small Plots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Satellite remote sensing has not been practical for agronomic research conducted in small plots due to spatial resolution issues. Objectives were to determine (1) the potential use of QuickBird high resolution digital images for estimating agronomic parameters of irrigated maize (Zea mays L.) grown...

  12. Relationship of sphinganine analog mycotoxin contamination in maize silage to seasonal weather conditions and to agronomic and ensiling practices.

    PubMed

    Mansfield, Michele A; Archibald, Douglas D; Jones, A Daniel; Kuldau, Gretchen A

    2007-04-01

    ABSTRACT Sphinganine analog mycotoxins (SAMs) are reported in maize and maize based feeds. Our objectives were to detect and quantify fumonisins B(1) and B(2) and Alternaria toxins (AAL toxins) AAL-TA and AAL-TB and determine how agronomic practices, weather conditions, and ensiling affected the occurrence and levels in maize silage. Silage was collected at harvest and after ensiling in 2001 and 2002 from 30 to 40 dairies, representing four regions in Pennsylvania. SAMs were quantified using high pressure liquid chromatography (HPLC) with fluorescence detection and high pressure liquid chromatography-mass spectrometry HPLC-MS. The average concentrations and ranges were as follows: fumonisin B(1) 2.02 mug/g (0.20 to 10.10), fumonisin B(2) 0.98 mug/g (0.20 to 20.30), AAL-TA 0.17 mug/g (0.20 to 2.01), and AAL-TB 0.05 mug/g (0.03 to 0.90). Fumonisin B(1) was the most frequently detected toxin (92%) in all samples, followed by fumonisin B(2) (55%), AAL-TA (23%), and -TB (13%). Temperature during maize development was positively correlated with fumonisin occurrence and levels and negatively with AAL-TA, while moisture events were negatively correlated with fumonisins and positively with AAL-TA. Fumonisin levels were higher in silage harvested at later developmental stages (dough through physiological maturity). Ensiling did not affect toxin concentration nor did agronomic practices (tillage system, inoculant use, or silo type) or silage characteristics (dry matter, pH, or organic acid concentration). This is the first report of AAL-TB in silage and on factors that affect SAM frequency and levels in maize silage. PMID:18943291

  13. A Large-Scale Screen for Artificial Selection in Maize Identifies Candidate Agronomic Loci for Domestication and Crop ImprovementW⃞

    PubMed Central

    Yamasaki, Masanori; Tenaillon, Maud I.; Vroh Bi, Irie; Schroeder, Steve G.; Sanchez-Villeda, Hector; Doebley, John F.; Gaut, Brandon S.; McMullen, Michael D.

    2005-01-01

    Maize (Zea mays subsp mays) was domesticated from teosinte (Z. mays subsp parviglumis) through a single domestication event in southern Mexico between 6000 and 9000 years ago. This domestication event resulted in the original maize landrace varieties, which were spread throughout the Americas by Native Americans and adapted to a wide range of environmental conditions. Starting with landraces, 20th century plant breeders selected inbred lines of maize for use in hybrid maize production. Both domestication and crop improvement involved selection of specific alleles at genes controlling key morphological and agronomic traits, resulting in reduced genetic diversity relative to unselected genes. Here, we sequenced 1095 maize genes from a sample of 14 inbred lines and chose 35 genes with zero sequence diversity as potential targets of selection. These 35 genes were then sequenced in a sample of diverse maize landraces and teosintes and tested for selection. Using two statistical tests, we identified eight candidate genes. Extended gene sequencing of these eight candidate loci confirmed that six were selected throughout the gene, and the remaining two exhibited evidence of selection in the 3′ portion of each gene. The selected genes have functions consistent with agronomic selection for nutritional quality, maturity, and productivity. Our large-scale screen for artificial selection allows identification of genes of potential agronomic importance even when gene function and the phenotype of interest are unknown. PMID:16227451

  14. 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

  15. 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

  16. 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

  17. 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...

  18. Relationships of resistance to Furarium ear rot and fumonisin contamination with agronomic performance of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to Fusarium ear rot and fumonisin contamination is heritable and controlled by at least 11 gene regions in a maize population created by backcrossing the highly resistant donor line, GE440, to the susceptible but commercially successful recurrent parent line, FR1064. To investigate the r...

  19. 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

  20. QTL mapping of agronomic waterlogging tolerance using recombinant inbred lines derived from tropical maize (Zea mays L) germplasm.

    PubMed

    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

  1. 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...

  2. 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

  3. 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

  4. Genome Wide Association Studies Using a New Nonparametric Model Reveal the Genetic Architecture of 17 Agronomic Traits in an Enlarged Maize Association Panel

    PubMed Central

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

    2014-01-01

    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. PMID:25211220

  5. Association Mapping in Turkish Olive Cultivars Revealed Significant Markers Related to Some Important Agronomic Traits.

    PubMed

    Kaya, Hilal Betul; Cetin, Oznur; Kaya, Hulya Sozer; Sahin, Mustafa; Sefer, Filiz; Tanyolac, Bahattin

    2016-08-01

    Olive (Olea europaea L.) is one of the most important fruit trees especially in the Mediterranean countries due to high consumption of table olive and olive oil. In olive breeding, the phenotypic traits associated to fruit are the key factors that determine productivity. Association mapping has been used in some tree species and a lot of crop plant species, and here, we perform an initial effort to detect marker-trait associations in olive tree. In the current study, a total of 96 olive genotypes, including both oil and table olive genotypes from Turkish Olive GenBank Resources, were used to examine marker-trait associations. For olive genotyping, SNP, AFLP, and SSR marker data were selected from previously published study and association analysis was performed between these markers and 5 yield-related traits. Three different approaches were used to check for false-positive results in association tests, and association results obtained from these models were compared. Using the model utilizing both population structure and relative kinship, eleven associations were significant with FDR ≤ 0.05. The largest number of significant associations was detected for fruit weight and stone weight. Our results suggested that association mapping could be an effective approach for identifying marker-trait associations in olive genotypes, without the development of mapping populations. This study shows for the first time the use of association mapping for identifying molecular markers linked to important traits in olive tree. PMID:27209034

  6. Polymorphisms in monolignol biosynthetic genes are associated with biomass yield and agronomic traits in European maize (Zea mays L.)

    PubMed Central

    2010-01-01

    Background Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes involved in cell wall lignification have been shown to influence both cell wall digestibility and yield traits. Results In this study, associations between monolignol biosynthetic genes and plant height (PHT), days to silking (DTS), dry matter content (DMC), and dry matter yield (DMY) were identified by using a panel of 39 European elite maize lines. In total, 10 associations were detected between polymorphisms or tight linkage disequilibrium (LD) groups within the COMT, CCoAOMT2, 4CL1, 4CL2, F5H, and PAL genomic fragments, respectively, and the above mentioned traits. The phenotypic variation explained by these polymorphisms or tight LD groups ranged from 6% to 25.8% in our line collection. Only 4CL1 and F5H were found to have polymorphisms associated with both yield and forage quality related characters. However, no pleiotropic polymorphisms affecting both digestibility of neutral detergent fiber (DNDF), and PHT or DMY were discovered, even under less stringent statistical conditions. Conclusion Due to absence of pleiotropic polymorphisms affecting both forage yield and quality traits, identification of optimal monolignol biosynthetic gene haplotype(s) combining beneficial quantitative trait polymorphism (QTP) alleles for both quality and yield traits appears possible within monolignol biosynthetic genes. This is beneficial to maximize forage and bioethanol yield per unit land area. PMID:20078869

  7. 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…

  8. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoalexins constitute a broad category of pathogen and insect-inducible biochemicals that locally protect plant tissues. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquite...

  9. Seed-specific expression of a lysine-rich protein gene, GhLRP, from cotton significantly increases the lysine content in maize seeds.

    PubMed

    Yue, Jing; Li, Cong; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2014-01-01

    Maize seed storage proteins are a major source of human and livestock consumption. However, these proteins have poor nutritional value, because they are deficient in lysine and tryptophan. Much research has been done to elevate the lysine content by reducing zein content or regulating the activities of key enzymes in lysine metabolism. Using the naturally lysine-rich protein genes, sb401 and SBgLR, from potato, we previously increased the lysine and protein contents of maize seeds. Here, we examined another natural lysine-rich protein gene, GhLRP, from cotton, which increased the lysine content of transgenic maize seeds at levels varying from 16.2% to 65.0% relative to the wild-type. The total protein content was not distinctly different, except in the six transgenic lines. The lipid and starch levels did not differ substantially in Gossypium hirsutum L. lysine-rich protein (GhLRP) transgenic kernels when compared to wild-type. The agronomic characteristics of all the transgenic maize were also normal. GhLRP is a high-lysine protein candidate gene for increasing the lysine content of maize. This study provided a valuable model system for improving maize lysine content. PMID:24681583

  10. 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

  11. 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

  12. Kauralexins: newly discovered ent-kaurane-related diterpenoid phytoalexins in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoalexins are pathogen and insect-inducible biochemicals that are deployed to locally inhibit further biotic attack. Due its agronomic significance, maize has been extensively investigated for terpenoid-based defenses including insect-inducible terpene volatiles which function as indirect defense...

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed p...

  18. 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. PMID:25659111

  19. 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

  20. 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.

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

    PubMed

    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. PMID:26589829

  2. 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

    2015-11-01

    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.

  3. A Genome-Wide Association Study Reveals Genes Associated with Fusarium Ear Rot Resistance in a Maize Core Diversity Panel

    PubMed Central

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

    2013-01-01

    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

  4. 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

  5. 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

  6. 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. PMID:26720856

  7. 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

  8. 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...

  9. Panzea: A Database and Resource for Molecular and Functional Diversity in the Maize Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize, a classical model for genetic studies, is an important agronomic crop, and the genome is known to contain many natural differences in the DNA between different strains. On average, two randomly chosen maize lines have an average of one single nucleotide polymorphism (SNP) every ~100 bp; this...

  10. 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), ...

  11. Use of a crop climate modeling system to evaluate climate change adaptation practices: maize yield in East Africa

    NASA Astrophysics Data System (ADS)

    Moore, N. J.; Alagarswamy, G.; Andresen, J.; Olson, J.; Thornton, P.

    2013-12-01

    Sub Saharan African agriculture is dominated by small-scale farmers and is heavily depend on growing season precipitation. Recent studies indicate that anthropogenic- induced warming including the Indian Ocean sea surface significantly influences precipitation in East Africa. East Africa is a useful region to assess impacts of future climate because of its large rainfall gradient, large percentage of its area being sub-humid or semi-arid, complex climatology and topography, varied soils, and because the population is particularly vulnerable to shifts in climate. Agronomic adaptation practices most commonly being considered include include a shift to short season, drought resistant maize varieties, better management practices especially fertilizer use, and irrigation. The effectiveness of these practices with climate change had not previously been tested. We used the WorldClim data set to represent current climate and compared the current and future climate scenarios of 4 Global Climate Models (GCMs) including a wetter (CCSM) and drier (HadCM3) GCM downscaled to 6 km resolution. The climate data was then used in the process-based CERES maize crop model to simulate the current period (representing 1960- 1990) and change in future maize production (from 2000 to 2050s). The effectiveness of agronomic practices, including short duration maize variety, fertilizer use and irrigation, to reduce projected future yield losses due to climate change were simulated. The GCMs project an increase in maximum temperature during growing season ranging from 1.5 to 3°C. Changes in precipitation were dependent on the GCM, with high variability across different topographies land cover types and elevations. Projected warmer temperatures in the future scenarios accelerated plant development and led to a reduction in growing season length and yields even where moisture was sufficient Maize yield changes in 2050 relative to the historical period were highly varied, in excess of +/- 500 kg

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

    2014-01-01

    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

  18. 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. PMID:25922491

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

    PubMed

    Mejía-Guerra, María Katherine; Li, Wei; Galeano, Narmer F; Vidal, Mabel; Gray, John; Doseff, Andrea I; Grotewold, Erich

    2015-12-01

    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

  20. 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

  1. 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

  2. Maize Disease Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Worldwide losses in maize due to disease (not including animals or viruses) were estimated to be about 9% in 2001-3 . This varied significantly by region with estimates of 4% in northern Europe and 14% in West Africa and South Asia (http://www.cabicompendium.org/cpc/economic.asp). Losses have tende...

  3. Positional cloning in maize (Zea mays subsp. mays, Poaceae)1

    PubMed Central

    Gallavotti, Andrea; Whipple, Clinton J.

    2015-01-01

    • Premise of the study: Positional (or map-based) cloning is a common approach to identify the molecular lesions causing mutant phenotypes. Despite its large and complex genome, positional cloning has been recently shown to be feasible in maize, opening up a diverse collection of mutants to molecular characterization. • Methods and Results: Here we outline a general protocol for positional cloning in maize. While the general strategy is similar to that used in other plant species, we focus on the unique resources and approaches that should be considered when applied to maize mutants. • Conclusions: Positional cloning approaches are appropriate for maize mutants and quantitative traits, opening up to molecular characterization the large array of genetic diversity in this agronomically important species. The cloning approach described should be broadly applicable to other species as more plant genomes become available. PMID:25606355

  4. 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

  5. Laser spectrofluorometry of agronomic plants in vivo

    NASA Astrophysics Data System (ADS)

    Posudin, Yuri I.

    1997-05-01

    Laser spectrofluorometry of agronomic plants in vivo at the single leaf level permits to investigate the effects of the growth phase, part, nodal position and age of the leaf, agrochemical treatment, external physical factors and plant diseases on the chlorophyll fluorescence. Such a spectroscopic approach can give the possibility to monitoring the development and health status of agronomic plants during ontogenesis and under different stresses. The relevant spectral wavelengths and criteria which correlate with status of the plant were determined.

  6. 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

  7. 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

  8. 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

  9. 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...

  10. 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

  11. 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....

  12. Empirical analysis of selection screens for domestication and improvement loci in maize by extended DNA sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both domestication and crop improvement in maize (Zea mays ssp. mays) have involved selection of specific alleles at genes controlling key morphological and agronomic traits, resulting in reduced genetic diversity relative to unselected genes. This difference in genetic diversity has led to the dev...

  13. Length of Selection Around Candidate Genes for Artificial Selection During Domestication and Crop Improvement in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic screens for artificial selection have been successful in identifying candidate genes for agronomic traits in maize (Zea mays L). However, the validity of the candidates identified requires that selection sweeps are very short, only containing the candidate gene with the nearest neighboring g...

  14. 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

  15. Improvement of hybrid yield by advanced backcross QTL analysis in elite maize.

    PubMed

    Ho, C.; McCouch, R.; Smith, E.

    2002-08-01

    We applied an advanced backcross breeding strategy to identify quantitative trait loci (QTLs) of agronomic importance in a cross between two elite inbreds of maize, RD6502 (Mo17-type recurrent parent) and RD3013 (Iodent donor parent). Two hundred and four BC(2) families were scored at 106 SSR, 15 AFLP, and 38 Heartbreaker (MITE) loci. BC(2) testcrosses (TC) with B73 were phenotyped at six locations in the Midwest and N.Y. We detected four grain yield, six grain moisture, and three plant height QTLs at which the RD3013 allele had a favorable effect ( p < 0.05). All four yield QTLs were selected as target introgressions in the development of BC(3)TC families. As predicted by BC(2)TC analysis, BC(3)TC entries containing introgressions at yld3.1 and yld10.1 significantly outperformed non-carrier entries by 11.1% (15.6 bu/A at one location) and 6.7% (7.1 bu/A averaged across two locations), respectively, in replicated Midwestern trials ( p < 0.05). Detection of yld10.1 effects in the BC(2)TC by spatial analysis (i.e., incomplete block, response surface, autoregressive, moving average or autoregressive moving average), but not by conventional single point analysis or interval mapping, indicated the utility of local environmental control for QTL mapping in unreplicated maize progeny. This work demonstrated that the advanced backcross QTL method can be applied to identify and manipulate useful QTLs in heterotic inbreds of elite maize. Genetic gains by this approach can be coupled with the maintenance and selection of favorable epistatic gene complexes by traditional hybrid breeding for maize improvement. PMID:12582549

  16. Coordination of the maize transcriptome by a conserved circadian clock

    PubMed Central

    2010-01-01

    Background The plant circadian clock orchestrates 24-hour rhythms in internal physiological processes to coordinate these activities with daily and seasonal changes in the environment. The circadian clock has a profound impact on many aspects of plant growth and development, including biomass accumulation and flowering time. Despite recent advances in understanding the circadian system of the model plant Arabidopsis thaliana, the contribution of the circadian oscillator to important agronomic traits in Zea mays and other cereals remains poorly defined. To address this deficit, this study investigated the transcriptional landscape of the maize circadian system. Results Since transcriptional regulation is a fundamental aspect of circadian systems, genes exhibiting circadian expression were identified in the sequenced maize inbred B73. Of the over 13,000 transcripts examined, approximately 10 percent displayed circadian expression patterns. The majority of cycling genes had peak expression at subjective dawn and dusk, similar to other plant circadian systems. The maize circadian clock organized co-regulation of genes participating in fundamental physiological processes, including photosynthesis, carbohydrate metabolism, cell wall biogenesis, and phytohormone biosynthesis pathways. Conclusions Circadian regulation of the maize genome was widespread and key genes in several major metabolic pathways had circadian expression waveforms. The maize circadian clock coordinated transcription to be coincident with oncoming day or night, which was consistent with the circadian oscillator acting to prepare the plant for these major recurring environmental changes. These findings highlighted the multiple processes in maize plants under circadian regulation and, as a result, provided insight into the important contribution this regulatory system makes to agronomic traits in maize and potentially other C4 plant species. PMID:20576144

  17. [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

  18. 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

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

    PubMed

    Dyer, George A; Taylor, J Edward

    2008-01-15

    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

  20. Diversity of maize kernels from a breeding program for protein quality: I. Physical, biochemical, nutrient, and color traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is a challenge to breed maize (Zea mayz L.) varieties with enhanced levels of protein, oil, starch and essential amino acid contents while maintaining competitive agronomic capability. We employed multivariate statistical procedures to quantify diversity and its components for 31 physical, bioche...

  1. [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

  2. Historical genomics of North American maize.

    PubMed

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

    2012-07-31

    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

  3. 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...

  4. Maize aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the most economically important food crops grown on acid soils, where aluminum (Al) toxicity greatly limits crop yields. Considerable variation for Al tolerance exists in maize, and this variation has been exploited for many years by plant breeders to enhance maize Al tolerance. Curr...

  5. Agriculture: Weather dilemma for African maize

    NASA Astrophysics Data System (ADS)

    Auffhammer, Maximilian

    2011-04-01

    The impact of climate change on food production remains uncertain, particularly in the tropics. Research that exploits the results of historical crop trials indicates that Africa's maize crop could be at risk of significant yield losses.

  6. 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...

  7. [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

  8. 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

  9. 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. PMID:24786079

  10. 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 ...

  11. 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

  12. 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

  13. 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

  14. Comparative study on concentrations of deoxynivalenol and zearalenone in kernels of transgenic Bt maize hybrids and nontransgenic maize hybrids.

    PubMed

    Valenta, H; Dänicke, S; Flachowsky, G; Böhme, T

    2001-03-01

    Ears from seven pairs of Bt maize hybrids / isogenic maize hybrids from field experiments in the year 1999 were collected arbitrarily and divided into corn borer (ECB) infested and not infested ears, respectively. The kernels were analysed for the mycotoxins deoxynivalenol (DON) and zearalenone (ZON).The percentage of infested ears was significantly lower in case of Bt maize (5%) as compared with non transgenic maize (31%). The study demonstrated further that the DON concentration in kernels of ECB infested ears of the non Bt maize hybrids was significantly higher than the DON concentration of the other groups. In the case of zearalenone, the same trend was observed. When the mean concentrations of the Bt and non-Bt hybrids, respectively, are considered, the lower contamination of Bt maize hybrids with DON and ZON, compared with their isogenic counterparts, is even more evident. PMID:23605751

  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. PMID:24665774

  16. Production of transgenic rice with agronomically useful genes: an assessment.

    PubMed

    Giri, C C; Vijaya Laxmi, G

    2000-12-01

    Rice is the most important food crop in tropical and subtropical regions of the world. Yield enhancement to increase rice production is one of the essential strategies to meet the demand for food of the growing population. Both abiotic and biotic features limit adversely the productivity of rice growing areas. Conventional breeding has been an effective means for developing high yielding varieties, however; it is associated with its own limitations. It is envisaged that recent trends in biotechnology can contribute to the agronomic improvement of rice in terms of yield and nutritional quality as a supplement to traditional breeding methods. Genetic transformation of rice has demonstrated numerous important opportunities resulting in the genetic improvement of existing elite rice varieties and production of new plant types. Significant advances have been made in the genetic engineering of rice since the first transgenic rice plant production in the late 1980s. Several gene transfer protocols have been employed successfully for the introduction of foreign genes to rice. In more than 60 rice cultivars belonging to indica, japonica, javanica, and elite African cultivars, the protocol has been standardized for transgenic rice production. Selection and use of appropriate promoters, selectable markers, and reporter genes has been helpful for development of efficient protocols for transgenic rice in a number of rice cultivars. The present review is an attempt to assess the current state of development in transgenic rice for the transfer of agronomically useful genes, emphasizing the application and future prospects of transgenic rice production for the genetic improvement of this food crop. PMID:14538093

  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. 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...

  19. 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...

  20. Sorghum and Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum and maize are closely related cereal grains grown throughout the world. Sorghum, a drought tolerant crop grown in semi-arid regions, is a basic food staple in many parts of the developing world, while primarily an animal feed in western countries. Maize, a major worldwide crop, is used for...

  1. 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 ...

  2. The kinetics of urinary fumonisin excretion in humans consuming maize-based foods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonisins (FB) are mycotoxins found in maize worldwide. In Central America, South America and Mexico, maize-based foods are often a major part of the diet and FB intake can also be high. A study in Mexico found a significant correlation between urinary FB1 and maize tortilla consumption. The purpos...

  3. A maize (Zea mays) line resistant to herbivory constitutively releases (E)-B-caryophyllene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) is an important agricultural crop. Various insect pests such as those in the order of Lepidoptera frequently feed on young maize plants and pose a significant threat to plant development and survival. To deal with this problem, maize generates a wide variety of responses to att...

  4. 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)

  5. 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)

  6. 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)

  7. 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. PMID:24472209

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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. PMID:25300834

  16. 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

  17. Maize flour fortification in Africa: markets, feasibility, coverage, and costs.

    PubMed

    Fiedler, John L; Afidra, Ronald; Mugambi, Gladys; Tehinse, John; Kabaghe, Gladys; Zulu, Rodah; Lividini, Keith; Smitz, Marc-Francois; Jallier, Vincent; Guyondet, Christophe; Bermudez, Odilia

    2014-04-01

    The economic feasibility of maize flour and maize meal fortification in Kenya, Uganda, and Zambia is assessed using information about the maize milling industry, households' purchases and consumption levels of maize flour, and the incremental cost and estimated price impacts of fortification. Premix costs comprise the overwhelming share of incremental fortification costs and vary by 50% in Kenya and by more than 100% across the three countries. The estimated incremental cost of maize flour fortification per metric ton varies from $3.19 in Zambia to $4.41 in Uganda. Assuming all incremental costs are passed onto the consumer, fortification in Zambia would result in at most a 0.9% increase in the price of maize flour, and would increase annual outlays of the average maize flour-consuming household by 0.2%. The increases for Kenyans and Ugandans would be even less. Although the coverage of maize flour fortification is not likely to be as high as some advocates have predicted, fortification is economically feasible, and would reduce deficiencies of multiple micronutrients, which are significant public health problems in each of these countries. PMID:24102661

  18. Lady Beetle (Coleoptera: Coccinellidae) Communities in Soybean and Maize.

    PubMed

    Prescott, K K; Andow, D A

    2016-02-01

    Coccinellids provide the most effective natural control of soybean aphid, but outbreaks remain common. Previous work suggests that native coccinellids are rare in soybean, potentially limiting soybean aphid control. We compared the coccinellid community in soybean with that of maize to identify differences in how coccinellid species use these habitats. As maize has long been used by coccinellids in the Americas, we hypothesized that coccinellids native to the Americas would use maize habitats, while exotic coccinellids would be more common in soybean. We identified and quantified aphids and all species and stages of coccinellids in a randomized complete block experiment with four blocks of 10 by 10 -m plots of soybean and maize in central Minnesota during 2008 and 2009. Coccinellid egg masses were identified by hatching in the laboratory. We used repeated-measures ANOVA to identify the dominant species in each habitat and compared species richness and Shannon's diversity with a paired t-test. Aphids and coccinellids had a similar phenology across habitats, but the coccinellid species composition differed significantly between soybean and maize. In soybean, the exotic, Harmonia axyridis Pallas, was the dominant species, while in maize, H. axyridis and the native, Coleomegilla maculata De Geer, were co-dominant. Eggs of H. axyridis were abundant in both habitats. In contrast, C. maculata eggs were very rare in soybean, despite being abundant in adjacent plots of maize. Species diversity was higher in maize. These findings were consistent with other published studies of coccinellid communities in these habitats. PMID:26396229

  19. 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

  20. Maize Photoperiod Control: Part II

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the 2007 and 2008 seasons, the staff of the Germplasm Enhancement of Maize Project and the Maize Curatorial Project staff of the North Central Regional Plant Introduction Station experimented with various types of structures to ensure that field plantings of tropical maize germplasm were expo...

  1. 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. PMID:9709236

  2. Mapping the distribution of maize streak virus genotypes across the forest and transition zones of Ghana.

    PubMed

    Oppong, Allen; Offei, Samuel K; Ofori, Kwadwo; Adu-Dapaah, Hans; Lamptey, Joseph N L; Kurenbach, Brigitta; Walters, Matthew; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind

    2015-02-01

    Throughout sub-Saharan Africa, maize streak virus strain A (MSV-A), the causal agent of maize streak disease (MSD), is an important biological constraint on maize production. In November/December 2010, an MSD survey was carried out in the forest and transition zones of Ghana in order to obtain MSV-A virulence sources for the development of MSD-resistant maize genotypes with agronomic properties suitable for these regions. In 79 well-distributed maize fields, the mean MSD incidence was 18.544 % and the symptom severity score was 2.956 (1 = no symptoms and 5 = extremely severe). We detected no correlation between these two variables. Phylogenetic analysis of cloned MSV-A isolates that were fully sequenced from samples collected in 51 of these fields, together with those sampled from various other parts of Africa, indicated that all of the Ghanaian isolates occurred within a broader cluster of West African isolates, all belonging to the highly virulent MSV-A1 subtype. Besides being the first report of a systematic MSV survey in Ghana, this study is the first to characterize the full-genome sequences of Ghanaian MSV isolates. The 51 genome sequences determined here will additionally be a valuable resource for the rational selection of representative MSV-A variant panels for MSD resistance screening. PMID:25344899

  3. 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

  4. 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

  5. QTL Mapping of Combining Ability and Heterosis of Agronomic Traits in Rice Backcross Recombinant Inbred Lines and Hybrid Crosses

    PubMed Central

    Luo, Junyuan; Wang, Peng; Yu, Sibin; Mou, Tongmin; Zheng, Xingfei; Hu, Zhongli

    2012-01-01

    Background Combining ability effects are very effective genetic parameters in deciding the next phase of breeding programs. Although some breeding strategies on the basis of evaluating combining ability have been utilized extensively in hybrid breeding, little is known about the genetic basis of combining ability. Combining ability is a complex trait that is controlled by polygenes. With the advent and development of molecular markers, it is feasible to evaluate the genetic bases of combining ability and heterosis of elite rice hybrids through QTL analysis. Methodology/Principal Findings In the present study, we first developed a QTL-mapping method for dissecting combining ability and heterosis of agronomic traits. With three testcross populations and a BCRIL population in rice, biometric and QTL analyses were conducted for ten agronomic traits. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and non-additive effects on expression levels. A large number of additive effect QTLs associated with performance per se of BCRIL and general combining ability, and dominant effect QTLs associated with special combining ability and heterosis were identified for the ten traits. Conclusions/Significance The combining ability of agronomic traits could be analyzed by the QTL mapping method. The characteristics revealed by the QTLs for combining ability of agronomic traits were similar with those by multitudinous QTLs for agronomic traits with performance per se of BCRIL. Several QTLs (1–6 in this study) were identified for each trait for combining ability. It demonstrated that some of the QTLs were pleiotropic or linked tightly with each other. The identification of QTLs responsible for combining ability and heterosis in the present study provides valuable information for dissecting genetic basis of combining ability. PMID:22291881

  6. Identification of maize genes associated with host plant resistance and susceptibility to Aspergillus flavus infection and aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. 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

  8. Silicon Improves Maize Photosynthesis in Saline-Alkaline Soils

    PubMed Central

    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 (Pn), stomatal conductance (gs), transpiration rate (E), and intercellular CO2 concentration (Ci) 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 Pn, gs, and Ci 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

  9. 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...

  10. 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’, ‘...

  11. Agronomic and Environmental Implications of Enhanced s-Triazine Degradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel catabolic pathways enabling rapid detoxification of s-triazine herbicides have been elucidated and detected at a growing number of locations. Herein we describe the potential agronomic and environmental ramifications of these bacterial adaptations. The genes responsible for s-triazine minera...

  12. Repeatability of agronomic traits in Panicum maximum (Jacq.) hybrids.

    PubMed

    Braz, T G S; Fonseca, D M; Jank, L; Cruz, C D; Martuscello, J A

    2015-01-01

    When evaluating plants, in particular perennial species, it is common to obtain repeated measures of a given trait from the same individual to evaluate the traits' repeatability in successive harvests. The degree of correlation among these measures defines the coefficient of repeatability, which has been widely utilized in the study of forage traits of interest for breeding. The objective of the present study was to evaluate the repeatability of agronomic traits in Panicum maximum hybrids. Hybrids from three progenies totaling 320 hybrids were evaluated in an incomplete-block design, with consideration of production and morpho-agronomic traits. Of the production traits, total dry matter and leaf dry matter showed the highest repeatability and varied from 0.540 to 0.769, whereas stem dry matter had lower coefficients (0.265-0.632). Among the morpho-agronomic traits, plant height and incidence of Bipolaris maydis had higher coefficients (0.118-0.460). The repeatability values of the agronomic traits were low-to-moderate, and six evaluations were sufficient to provide accuracy in the selection of hybrids regarding total dry matter, leaf dry matter, plant height, and incidence of B. maydis, whereas the other traits require more repeated measures to increase reliability in the prediction of their response. PMID:26782581

  13. Agronomic effectiveness of calcium phosphate recovered from liquid swine manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new manure treatment technology developed as an alternative to anaerobic lagoons on swine (Sus scrofa domesticus) farms includes solid-liquid separation and subsequent recovery of soluble phosphorus (P) as calcium phosphate from the wastewater. The objective was to determine the agronomic effectiv...

  14. AGRONOMIC EVALUATION OF SMOOTH ROOT RELEASES AND PROSPECTIVE RELEASES - 2001

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Performance evaluations for standard agronomic parameters as well as root suture prominence score were conducted on 10 experimental and two standard commercial hybrids. Recoverable White Sugar per Acre (RWSA) was the most useful yield measurement. It was apparent that gains have been made in increas...

  15. 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...

  16. 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

  17. 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...

  18. MaizeGDB - Past, present, and future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year. This editorial outlines MaizeGDB's history and connection to the Maize Genetics Cooperation, describes key components of how the MaizeGDB interface will be completely redesigned over the course of the next two years to meet cur...

  19. Western corn rootworm and Bt maize: challenges of pest resistance in the field.

    PubMed

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

    2012-01-01

    Crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) manage many key insect pests while reducing the use of conventional insecticides. One of the primary pests targeted by Bt maize in the United States is the western corn rootworm, Diabrotica virgifera virgifera LeConte. Beginning in 2009, populations of western corn rootworm were identified in Iowa, USA that imposed severe root injury to Cry3Bb1 maize. Subsequent laboratory bioassays revealed that these populations were resistant to Cry3Bb1 maize, with survival on Cry3Bb1 maize that was three times higher than populations not associated with such injury. Here we report the results of research that began in 2010 when western corn rootworm were sampled from 14 fields in Iowa, half of which had root injury to Cry3Bb1 maize of greater than 1 node. Of these samples, sufficient eggs were collected to conduct bioassays on seven populations. Laboratory bioassays revealed that these 2010 populations had survival on Cry3Bb1 maize that was 11 times higher and significantly greater than that of control populations, which were brought into the laboratory prior to the commercialization of Bt maize for control of corn rootworm. Additionally, the developmental delays observed for control populations on Cry3Bb1 maize were greatly diminished for 2010 populations. All 2010 populations evaluated in bioassays came from fields with a history of continuous maize production and between 3 and 7 y of Cry3Bb1 maize cultivation. Resistance to Cry34/35Ab1 maize was not detected and there was no correlation between survival on Cry3Bb1 maize and Cry34/35Ab1 maize, suggesting a lack of cross resistance between these Bt toxins. Effectively dealing with the challenge of field-evolved resistance to Bt maize by western corn rootworm will require better adherence to the principles of integrated pest management. PMID:22688688

  20. 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

  1. 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.

  2. 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

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

    PubMed Central

    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

  4. 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

    ABSTRACT 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. PMID:24918609

  5. 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

  6. 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

    2016-01-01

    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

  7. Betaine deficiency in maize

    SciTech Connect

    Lerma, C. ); Rich, P.J.; Ju, G.C.; Yang, Wenju; Rhodes, D. ); Hanson, A.D. )

    1991-04-01

    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. 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 {r arrow} betaine aldehyde step of betaine synthesis. Consistent with this location, betaine-deficient plants were shown to have no detectable endogenous pool of betaine aldehyde.

  8. (Genomic variation in maize)

    SciTech Connect

    Rivin, C.J.

    1991-01-01

    These studies have sought to learn how different DNA sequences and sequence arrangements contribute to genome plasticity in maize. We describe quantitative variation among maize inbred lines for tandemly arrayed and dispersed repeated DNA sequences and gene families, and qualitative variation for sequences homologous to the Mutator family of transposons. The potential of these sequences to undergo unequal crossing over, non-allelic (ectopic) recombination and transposition makes them a source of genome instability. We have found examples of rapid genomic change involving these sequences in Fl hybrids, tissue culture cells and regenerated plants. We describe the repetitive portion of the maize genome as composed primarily of sequences that vary markedly in copy number among different genetic stocks. The most highly variable is the 185 bp repeat associated with the heterochromatic chromosome knobs. Even in lines without visible knobs, there is a considerable quantity of tandemly arrayed repeats. We also found a high degree of variability for the tandemly arrayed 5S and ribosomal DNA repeats. While such variation might be expected as the result of unequal cross-over, we were surprised to find considerable variation among lower copy number, dispersed repeats as well. One highly repeated sequence that showed a complex tandem and dispersed arrangement stood out as showing no detectable variability among the maize lines. In striking contrast to the variability seen between the inbred stocks, individuals within a stock were indistinguishable with regard to their repeated sequence multiplicities.

  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. 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. PMID:25822185

  11. 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

  12. [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

  13. 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. PMID:26452426

  14. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths

    PubMed Central

    Holst, Irene; Moreno, J. Enrique; Piperno, Dolores R.

    2007-01-01

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals. PMID:17978176

  15. 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

  16. 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

  17. 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

    2015-01-01

    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. PMID:25867359

  18. 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

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

    PubMed

    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

  20. 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. PMID:24767050

  1. 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

  2. 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...

  3. Genetic mechanisms of Maize dwarf mosaic virus resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize resistance to viruses has been well-characterized at the genetic level, and loci responsible for resistance to potyviruses including Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), have been mapped in several ge...

  4. 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...

  5. 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.

  6. 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

  7. 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

  8. Genetic variability in agronomic traits of a germplasm collection of hulless barley.

    PubMed

    Zeng, X Q

    2015-01-01

    Germplasm collections represent an important genetic source for crop improvements. In this study, 220 accessions of hulless barley were collected worldwide and their genetic diversity was investigated. Sixteen agronomic traits, including yield and yield components, grain morphology, leaf size, plant height, and lodging resistance, were assessed under field conditions. All studied traits exhibited large variation. Thousand seed weight determined yield, and was strongly affected by spike length and spike number. Four varieties, Gaoyuan Zao 1, Fu 8-4, Zang 0331, and Harry (WDM00618), showed high resistance to lodging. Significant correlations among the traits were observed, indicating trait interactions. Life cycle had the smallest coefficient of variation (CV) among native, foreign, and improved varieties, whereas the CV of cellulose content was more or less balanced. Among the accessions from domestic and foreign germplasm, the CV for life cycle remained the lowest, whereas those for carbon/nitrogen and spike number per plant were the highest. Interestingly, higher genetic diversity was observed in domestic than in foreign accessions. Together, our findings demonstrate that there is abundant diversity in worldwide hulless barley germplasm collections, which would be useful when introducing their desirable traits into cultivars of hulless barley to improve yield and other agronomic traits. PMID:26782483

  9. Genomic regions underlying agronomic traits in linseed (Linum usitatissimum L.) as revealed by association mapping.

    PubMed

    Soto-Cerda, Braulio J; Duguid, Scott; Booker, Helen; Rowland, Gordon; Diederichsen, Axel; Cloutier, Sylvie

    2014-01-01

    The extreme climate of the Canadian Prairies poses a major challenge to improve yield. Although it is possible to breed for yield per se, focusing on yield-related traits could be advantageous because of their simpler genetic architecture. The Canadian flax core collection of 390 accessions was genotyped with 464 simple sequence repeat markers, and phenotypic data for nine agronomic traits including yield, bolls per area, 1,000 seed weight, seeds per boll, start of flowering, end of flowering, plant height, plant branching, and lodging collected from up to eight environments was used for association mapping. Based on a mixed model (principal component analysis (PCA) + kinship matrix (K)), 12 significant marker-trait associations for six agronomic traits were identified. Most of the associations were stable across environments as revealed by multivariate analyses. Statistical simulation for five markers associated with 1000 seed weight indicated that the favorable alleles have additive effects. None of the modern cultivars carried the five favorable alleles and the maximum number of four observed in any accessions was mostly in breeding lines. Our results confirmed the complex genetic architecture of yield-related traits and the inherent difficulties associated with their identification while illustrating the potential for improvement through marker-assisted selection. PMID:24138336

  10. 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. PMID:17955996

  11. Unraveling the genetic architecture of subtropical maize (Zea mays L.) lines to assess their utility in breeding programs

    PubMed Central

    2013-01-01

    Background Maize is an increasingly important food crop in southeast Asia. The elucidation of its genetic architecture, accomplished by exploring quantitative trait loci and useful alleles in various lines across numerous breeding programs, is therefore of great interest. The present study aimed to characterize subtropical maize lines using high-quality SNPs distributed throughout the genome. Results We genotyped a panel of 240 subtropical elite maize inbred lines and carried out linkage disequilibrium, genetic diversity, population structure, and principal component analyses on the generated SNP data. The mean SNP distance across the genome was 70 Kb. The genome had both high and low linkage disequilibrium (LD) regions; the latter were dominant in areas near the gene-rich telomeric portions where recombination is frequent. A total of 252 haplotype blocks, ranging in size from 1 to 15.8 Mb, were identified. Slow LD decay (200–300 Kb) at r 2  ≤ 0.1 across all chromosomes explained the selection of favorable traits around low LD regions in different breeding programs. The association mapping panel was characterized by strong population substructure. Genotypes were grouped into three distinct clusters with a mean genetic dissimilarity coefficient of 0.36. Conclusions The genotyped panel of subtropical maize lines characterized in this study should be useful for association mapping of agronomically important genes. The dissimilarity uncovered among genotypes provides an opportunity to exploit the heterotic potential of subtropical elite maize breeding lines. PMID:24330649

  12. 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

  13. 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

  14. 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...

  15. 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...

  16. AN INTEGRATED MAP FOR MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Mapping Project (MMP) is focused on developing genetic, physical, and database resources for the maize genome. A key resource being developed by the MMP is a well-integrated genetic and physical map that will expedite the identification of DNA sequences underlying key traits that have been...

  17. 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...

  18. 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...

  19. 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.

  20. 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

  1. Reduced fitness of Daphnia magna fed a Bt-transgenic maize variety.

    PubMed

    Bøhn, Thomas; Primicerio, Raul; Hessen, Dag O; Traavik, Terje

    2008-11-01

    Genetically modified (GM) maize expressing the Bt-toxin Cry1Ab (Bt-maize) was tested for effects on survival, growth, and reproduction of the water flea Daphnia magna, a crustacean arthropod commonly used as a model organism in ecotoxicological studies. In three repeated experiments, D. magna were fed 100% ground maize in suspension, using either GM or isogenic unmodified (UM) maize. D. magna fed GM-maize showed a significantly reduced fitness performance: The mortality was higher, a lower proportion of females reached sexual maturation, and the overall egg production was lower compared to D. magna fed UM isogenic maize. We conclude that the tested variety of Bt-maize and its UM counterpart do not have the same quality as food sources for this widely used model organism. The combination of a reduced fitness performance combined with earlier onset of reproduction of D. magna fed Bt-maize indicates a toxic effect rather than a lower nutritional value of the GM-maize. PMID:18347840

  2. 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

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

    PubMed

    Lou, Yanhong; Hu, Longxing; 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

  4. 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...

  5. 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 ...

  6. Inverse correlation of ability to produce aflatoxin and aspergillus colonization of maize seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeds of aflatoxin-resistant and aflatoxin susceptible maize lines were inoculated with conidia of aflatoxin-producing Aspergillus flavus or A. parasiticus isolates or isogenic non-producing mutants. Conidial yields recovered from resistant maize seed after seven days were significantly lower for af...

  7. 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

  8. Aflatoxin control in maize by Trametes versicolor.

    PubMed

    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

  9. 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

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

    PubMed

    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

  11. 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

  12. Germplasm Enhancement of Maize - Strategies & Synergy with Maize Curation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The importance of access to and utilization of genetic plant resources for improvement of modern cultivars is widely recognized. Industry recognized the challenges of incorporating diversity into their elite breeding pools because of lack of adaptation and undesirable agronomic traits associat...

  13. Effects of Delaying Transplanting on Agronomic Traits and Grain Yield of Rice under Mechanical Transplantation Pattern

    PubMed Central

    Liu, Qihua; Wu, Xiu; Ma, Jiaqing; Chen, Bocong; Xin, Caiyun

    2015-01-01

    A delay in the mechanical transplantation (MT) of rice seedlings frequently occurs in Huanghuai wheat-rice rotation cropping districts of China, due to the late harvest of wheat, the poor weather conditions and the insufficiency of transplanters, missing the optimum transplanting time and causing seedlings to age. To identify how delaying transplanting rice affects the agronomic characteristics including the growth duration, photosynthetic productivity and dry matter remobilization efficiency and the grain yield under mechanical transplanting pattern, an experiment with a split-plot design was conducted over two consecutive years. The main plot includes two types of cultivation: mechanical transplanting and artificial transplanting (AT). The subplot comprises four japonica rice cultivars. The results indicate that the rice jointing, booting, heading and maturity stages were postponed under MT when using AT as a control. The tiller occurrence number, dry matter weight per tiller, accumulative dry matter for the population, leaf area index, crop growth rate, photosynthetic potential, and dry matter remobilization efficiency of the leaf under MT significantly decreased compared to those under AT. In contrast, the reduction rate of the leaf area during the heading-maturity stage was markedly enhanced under MT. The numbers of effective panicles and filled grains per panicle and the grain yield significantly decreased under MT. A significant correlation was observed between the dry matter production, remobilization and distribution characteristics and the grain yield. We infer that, as with rice from old seedlings, the decrease in the tiller occurrence, the photosynthetic productivity and the assimilate remobilization efficiency may be important agronomic traits that are responsible for the reduced grain yield under MT. PMID:25875607

  14. Effect of Bt maize and soil insecticides on yield, injury, and rootworm survival: implications for resistance management.

    PubMed

    Petzold-Maxwell, Jennifer L; Meinke, Lance J; Gray, Michael E; Estes, Ronald E; Gassmann, Aaron J

    2013-10-01

    A 2-yr field experiment was conducted to determine the effects on Diabrotica spp. (Coleoptera: Chrysomelidae) of an insecticidal seed treatment (Poncho 1250, (AI)/clothianidin) and a granular insecticide (Aztec 2.1G, (AI)/tebupirimphos and cyfluthrin) alone and in combination with maize producing the insectidical toxin Cry3Bb1 derived from the bacterium Bacillus thuringiensis (Bt). Yields for Bt maize plots were significantly greater than for non-Bt maize; however, insecticides did not significantly affect yield. Insecticides significantly decreased root injury in non-Bt maize plots, but there were no significant differences in root injury between Bt maize with or without either insecticide. Maize producing the Bt toxin Cry3Bb1 and the soil-applied insecticide Aztec significantly decreased survival of western corn rootworm (Diabrotica virgifera virgifera LeConte), while only Bt maize significantly decreased survival of the northern corn rootworm (Diabrotica barberi Smith & Lawrence). For both species, Bt maize and each of the insecticides delayed emergence. In the absence of density-dependent mortality, Bt maize imposed 71 and 80% reduction in survival on the western corn rootworm and the northern corn rootworm, respectively. The data from this study do not support combining insecticide with Bt maize because the addition of insecticide did not increase yield or reduce root injury for Bt maize, and the level of rootworm mortality achieved with conventional insecticide was likely too low to delay the evolution of Bt resistance. In addition, delays in emergence from Bt maize combined with insecticides could promote assortative mating among Bt-selected individuals, which may hasten resistance evolution. PMID:24224233

  15. Agronomic recycling of pig slurry and pig sewage

    NASA Astrophysics Data System (ADS)

    Gómez Garrido, Melisa; Sánchez García, Pablo; Faz Cano, Ángel; Büyükkılıç Yanardag, Asuman; Yanardag, Ibrahim; Kabas, Sebla; Ángeles Múñoz García, María; María Rosales Aranda, Rosa; Segura Ruíz, Juan Carlos

    2013-04-01

    Recycling pig slurry as organic fertilizer is a convenient and suitable way of waste elimination due to its low cost and high agronomic benefits. The objectives of this two year study are focused on improving and recycling pig slurry appropriately, and monitoring the soil-plant system at the same time. The evaluation of the agronomic effectiveness of different types of pig slurry (raw, solid, treated and depurated) in different doses (170 kg N ha-1 (legislated dose), 340 and 510 kg N ha-1) is innovative because the fertilizer value of each amendment can be balanced. Furthermore environmental issues such us volatilisation, leaching and salinisation have been considered for each treatment in order to set the viability of the study and to justify the treatments applied. Electrical conductivity, Kjeldhal nitrogen, sodium and potassium are the physico-chemical parameters most influenced in soils treated with doses 340 and 510 kg N ha-1. Additionally plant samples, especially halophyte, have shown the highest major and minor nutrients contents. Finally, pig slurry application in legislated doses could be considered a useful environmental practice; however, the development of the crop will be very influenced by the type of dose and amendment selected.

  16. 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

  17. 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...

  18. 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...

  19. POST-HARVEST STORAGE EFFECTS ON GUAYULE LATEX QUALITY FROM AGRONOMIC TRIALS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current guayule commercialization efforts are based upon the production of hypoallergenic latex. However, little is known about the optimal agronomic conditions for maximum latex production. A series of agronomic trials were carried out over four years to investigate latex yield and quality in diffe...

  20. 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. PMID:26540480

  1. 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

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

    PubMed

    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 PMID:26697001

  3. 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

  4. 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

  5. Maize Domestication and Anti-Herbivore Defences: Leaf-Specific Dynamics during Early Ontogeny of Maize and Its Wild Ancestors

    PubMed Central

    Maag, Daniel; Erb, Matthias; Bernal, Julio S.; Wolfender, Jean-Luc; Turlings, Ted C. J.; Glauser, Gaétan

    2015-01-01

    As a consequence of artificial selection for specific traits, crop plants underwent considerable genotypic and phenotypic changes during the process of domestication. These changes may have led to reduced resistance in the cultivated plant due to shifts in resource allocation from defensive traits to increased growth rates and yield. Modern maize (Zea mays ssp. mays) was domesticated from its ancestor Balsas teosinte (Z. mays ssp. parviglumis) approximately 9000 years ago. Although maize displays a high genetic overlap with its direct ancestor and other annual teosintes, several studies show that maize and its ancestors differ in their resistance phenotypes with teosintes being less susceptible to herbivore damage. However, the underlying mechanisms are poorly understood. Here we addressed the question to what extent maize domestication has affected two crucial chemical and one physical defence traits and whether differences in their expression may explain the differences in herbivore resistance levels. The ontogenetic trajectories of 1,4-benzoxazin-3-ones, maysin and leaf toughness were monitored for different leaf types across several maize cultivars and teosinte accessions during early vegetative growth stages. We found significant quantitative and qualitative differences in 1,4-benzoxazin-3-one accumulation in an initial pairwise comparison, but we did not find consistent differences between wild and cultivated genotypes during a more thorough examination employing several cultivars/accessions. Yet, 1,4-benzoxazin-3-one levels tended to decline more rapidly with plant age in the modern maize cultivars. Foliar maysin levels and leaf toughness increased with plant age in a leaf-specific manner, but were also unaffected by domestication. Based on our findings we suggest that defence traits other than the ones that were investigated are responsible for the observed differences in herbivore resistance between teosinte and maize. Furthermore, our results indicate

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Comparative analysis of maize (Zea mays) crop performance: natural variation, incremental improvements and economic impacts.

    PubMed

    Leibman, Mark; Shryock, Jereme J; Clements, Michael J; Hall, Michael A; Loida, Paul J; McClerren, Amanda L; McKiness, Zoe P; Phillips, Jonathan R; Rice, Elena A; Stark, Steven B

    2014-09-01

    Grain yield from maize hybrids continues to improve through advances in breeding and biotechnology. Despite genetic improvements to hybrid maize, grain yield from distinct maize hybrids is expected to vary across growing locations due to numerous environmental factors. In this study, we examine across-location variation in grain yield among maize hybrids in three case studies. The three case studies examine hybrid improvement through breeding, introduction of an insect protection trait or introduction of a transcription factor trait associated with increased yield. In all cases, grain yield from each hybrid population had a Gaussian distribution. Across-location distributions of grain yield from each hybrid partially overlapped. The hybrid with a higher mean grain yield typically outperformed its comparator at most, but not all, of the growing locations (a 'win rate'). These results suggest that a broad set of environmental factors similarly impacts grain yields from both conventional- and biotechnology-derived maize hybrids and that grain yields among two or more hybrids should be compared with consideration given to both mean yield performance and the frequency of locations at which each hybrid 'wins' against its comparators. From an economic standpoint, growers recognize the value of genetically improved maize hybrids that outperform comparators in the majority of locations. Grower adoption of improved maize hybrids drives increases in average U.S. maize grain yields and contributes significant value to the economy. PMID:24851925

  11. Evidence of selection at the ramosa1 locus during maize domestication.

    PubMed

    Sigmon, Brandi; Vollbrecht, Erik

    2010-04-01

    Modern maize was domesticated from Zea mays parviglumis, a teosinte, about 9000 years ago in Mexico. Genes thought to have been selected upon during the domestication of crops are commonly known as domestication loci. The ramosa1 (ra1) gene encodes a putative transcription factor that controls branching architecture in the maize tassel and ear. Previous work demonstrated reduced nucleotide diversity in a segment of the ra1 gene in a survey of modern maize inbreds, indicating that positive selection occurred at some point in time since maize diverged from its common ancestor with the sister species Tripsacum dactyloides and prompting the hypothesis that ra1 may be a domestication gene. To investigate this hypothesis, we examined ear phenotypes resulting from minor changes in ra1 activity and sampled nucleotide diversity of ra1 across the phylogenetic spectrum between tripsacum and maize, including a broad panel of teosintes and unimproved maize landraces. Weak mutant alleles of ra1 showed subtle effects in the ear, including crooked rows of kernels due to the occasional formation of extra spikelets, correlating a plausible, selected trait with subtle variations in gene activity. Nucleotide diversity was significantly reduced for maize landraces but not for teosintes, and statistical tests implied directional selection on ra1 consistent with the hypothesis that ra1 is a domestication locus. In maize landraces, a noncoding 3'-segment contained almost no genetic diversity and 5'-flanking diversity was greatly reduced, suggesting that a regulatory element may have been a target of selection. PMID:20196812

  12. Isolation and characterization of endophytic colonizing bacteria from agronomic crops and prairie plants.

    PubMed

    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

    2002-05-01

    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 log(10) 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 log(10) 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 log(10) 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 log(10) 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

  13. Many maize genes are expressed in an oat background carrying a specific maize chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat-maize addition (OMA) lines are derived from oat x maize sexual hybrids in which individual maize chromosomes have been retained in plants containing a full complement of oat chromosomes. Many of the OMA lines display specific phenotypes, which indicate that maize genes are likely expressed and c...

  14. Interactions among Bt maize, entomopathogens, and rootworm species (Coleoptera: Chrysomelidae) in the field: effects on survival, yield, and root injury.

    PubMed

    Petzold-Maxwell, Jennifer L; Jaronski, Stefan T; Clifton, Eric H; Dunbar, Mike W; Jackson, Mark A; Gassmann, Aaron J

    2013-04-01

    A 2 yr field study was conducted to determine how a blend of entomopathogens interacted with Bt maize to affect mortality of Diabrotica spp. (Coleoptera: Chrysomelidae), root injury to maize (Zea maize L.) and yield. The blend of entomopathogens included two entomopathogenic nematodes, Steinernema carpocapsae Weiser and Heterorhabditis bacteriophora Poinar, and one entomopathogenic fungus, Metarhizium brunneum (Metschnikoff) Sorokin. Bt maize (event DAS59122-7, which produces Bt toxin Cry34/35Ab1) decreased root injury and survival of western corn rootworm (Diabrotica virgifera virgifera LeConte) and northern corn rootworm (Diabrotica barberi Smith & Lawrence) but did not affect yield. During year 1 of the study, when rootworm abundance was high, entomopathogens in combination with Bt maize led to a significant reduction in root injury. In year 2 of the study, when rootworm abundance was lower, entomopathogens significantly decreased injury to non-Bt maize roots, but had no effect on Bt maize roots. Yield was significantly increased by the addition of entomopathogens to the soil. Entomopathogens did not decrease survival of corn rootworm species. The results suggest that soil-borne entomopathogens can complement Bt maize by protecting roots from feeding injury from corn rootworm when pest abundance is high, and can decrease root injury to non-Bt maize when rootworm abundance is low. In addition, this study also showed that the addition of entomopathogens to soil contributed to an overall increase in yield. PMID:23786047

  15. 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.

  16. 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

  17. 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

  18. Estimation of Wheat Agronomic Parameters using New Spectral Indices

    PubMed Central

    Jin, Xiu-liang; Diao, Wan-ying; Xiao, Chun-hua; Wang, Fang-yong; Chen, Bing; Wang, Ke-ru; Li, Shao-kun

    2013-01-01

    Crop agronomic parameters (leaf area index (LAI), nitrogen (N) uptake, total chlorophyll (Chl) content ) are very important for the prediction of crop growth. The objective of this experiment was to investigate whether the wheat LAI, N uptake, and total Chl content could be accurately predicted using spectral indices collected at different stages of wheat growth. Firstly, the product of the optimized soil-adjusted vegetation index and wheat biomass dry weight (OSAVI×BDW) were used to estimate LAI, N uptake, and total Chl content; secondly, BDW was replaced by spectral indices to establish new spectral indices (OSAVI×OSAVI, OSAVI×SIPI, OSAVI×CIred edge, OSAVI×CIgreen mode and OSAVI×EVI2); finally, we used the new spectral indices for estimating LAI, N uptake, and total Chl content. The results showed that the new spectral indices could be used to accurately estimate LAI, N uptake, and total Chl content. The highest R2 and the lowest RMSEs were 0.711 and 0.78 (OSAVI×EVI2), 0.785 and 3.98 g/m2 (OSAVI×CIred edge) and 0.846 and 0.65 g/m2 (OSAVI×CIred edge) for LAI, nitrogen uptake and total Chl content, respectively. The new spectral indices performed better than the OSAVI alone, and the problems of a lack of sensitivity at earlier growth stages and saturation at later growth stages, which are typically associated with the OSAVI, were improved. The overall results indicated that this new spectral indices provided the best approximation for the estimation of agronomic indices for all growth stages of wheat. PMID:24023639

  19. Estimated fumonisin exposure in Guatemala is greatest in consumers of lowland maize.

    PubMed

    Torres, Olga A; Palencia, Edwin; Lopez de Pratdesaba, Ligia; Grajeda, Ruben; Fuentes, Mario; Speer, Marcy C; Merrill, Alfred H; O'Donnell, Kerry; Bacon, Charles W; Glenn, Anthony E; Riley, Ronald T

    2007-12-01

    Fumonisin mycotoxins contaminate maize worldwide. Analysis of maize samples (n = 396) collected from fields in Guatemala from 2000 to 2003 found that lowland maize (<360 m) had significantly more fumonisin B1 than highland maize (>1200 m). For example, 78% of the lowland samples collected at harvest in 2002 contained >0.3 microg/g of fumonisin B1, whereas only 2% of the highland samples contained >0.3 microg/g. Maize from the 2002 crop collected from storage in the highlands just before the 2003 harvest contained significantly more fumonisin B1 compared with levels at harvest in 2002. All Fusarium-infected kernels analyzed from 9 random lowland locations in 2001 were infected with fumonisin-producing Fusarium verticillioides and no other Fusarium species, whereas in samples from the highlands, only 5% of the Fusarium-positive kernels were F. verticillioides. In 2005, maize samples (n = 236) from the 2004 crop were collected from local markets in 20 Departments across Guatemala. The analysis showed that maize from lowland locations was often highly contaminated with fumonisin and was frequently transported to and sold in highland markets. Thus, fumonisin exposure in the highlands will be greatest in groups that obtain their maize in the market place from commercial vendors. Based on a recall study and published consumption data, a preliminary assessment of daily intake of total fumonisins was estimated. Consumption of nixtamalized maize products made from >50% of the maize from commercial vendors in 2005 could result in exposure exceeding the recommended WHO provisional maximal tolerable daily intake. PMID:18029490

  20. Consequences for Protaphorura armata (Collembola: Onychiuridae) following exposure to genetically modified Bacillus thuringiensis (Bt) maize and non-Bt maize.

    PubMed

    Heckmann, Lars-Henrik; Griffiths, Bryan S; Caul, Sandra; Thompson, Jacqueline; Pusztai-Carey, Marianne; Moar, William J; Andersen, Mathias N; Krogh, Paul Henning

    2006-07-01

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. PMID:16310913

  1. Analysis of genetic traits for drought tolerance in maize.

    PubMed

    Muhammad, R W; Qayyum, A; Hamza, A; Ahmad, M Q; Naseer, N S; Liaqat, S; Ahmad, B; Malik, W; Noor, E

    2015-01-01

    Fifty-four genotypes of maize were crossed and evaluated in the field during the crop season in February 2012 under both normal and water stress conditions. To identify the major parameters responsible for variation among genotypes, single linkage cluster analysis and principle component analysis (PCA) were carried out. Thirteen characters were studied. The PCA showed that the first six components, with eigen values >1, contributed 82.30% of the variability among the genotypes under normal field irrigation conditions while other PCs (7-13) had eigen values less than 1. Under drought conditions, the first four PCs, with eigen values >1, contributed 64.79% of the variability among genotypes while the other PCs (5-13) had eigen values less than 1. In the absence of water stress, heritability ranged from 68% (sucrose content) to 99% (plant height) and genetic advance ranged between 158.43% for stomatal frequency and 0.87 for biological yield. Under drought conditions, the coefficient of variability (CV) was 1.43-7.79, whereas estimates of heritability ranged between 68% and 99% for sucrose content and leaf area, respectively. The values of genetic advance ranged between 153.41 for stomatal frequency and 0.47 for nitrogen content. CV was 1.52-7.38 under drought conditions. The results indicated that the plant characters studied were under the control of additive genetic effects and suggested that selection should lead to fast genetic improvements. Clusters with superior agronomic types were identified and could be exploited for the transfer of desirable genes to improve the yield potential of the maize crop. PMID:26535668

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. MaizeGDB Becomes Sequence-centric

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 bett...

  11. Proteome Profile of the Developing Maize (Zea mays L.) Rachis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection of the developing maize (Zea mays L.) ear with the pathogenic fungus Aspergillus flavus, which produces the carcinogen aflatoxin, is a serious agricultural problem causing significant economic losses worldwide. The rachis (or cob) is an important structure that fungus uses to spread within...

  12. Methane emissions, feed intake, and performance of finishing beef cattle offered maize silages harvested at 4 different stages of maturity.

    PubMed

    Mc Geough, E J; O'Kiely, P; Foley, P A; Hart, K J; Boland, T M; Kenny, D A

    2010-04-01

    when methane was expressed per kilogram of carcass gain. Advancing maize maturity did not result in significant linear or quadratic responses in methane output proportional to GE intake. The ALC diet resulted in less methane output than the maize silage treatments irrespective of the unit of expression. In conclusion, advancing maize harvest maturity did not affect beef cattle performance but reduced methane output relative to DMI and carcass gain. Cattle offered ALC exhibited greater rates of BW gain and less emission of methane compared with cattle offered any of the maize silage treatments. PMID:20023131

  13. 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

  14. Prediction of maize seed attributes using a rapid single kernel near infrared instrument

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-destructive measurements of seed attributes would significantly enhance breeder selection of seeds with specific traits and potentially improve hybrid development. A single kernel near infrared reflectance (NIR) instrument was developed for rapidly predicting maize grain attributes, which would ...

  15. 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. PMID:25300835

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. Genome-wide association study dissects the genetic architecture of oil biosynthesis and accumulation in maize kernel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Genome Wide Association Study (GWAS) on a population of 368 maize inbreds with 1.06 million SNPs was performed and identified 74 highly significantly associated genes influencing maize kernel oil content and fatty acid composition. To validate these findings, three biparental linkage mapping popul...

  1. Proteomic analysis of the maize rachis: Potential roles of constitutive and induced proteins in resistance to Aspergillus flavus and aflatoxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection of the maize (Zea mays L.) with aflatoxigenic fungus Aspergillus flavus and consequent contamination with carcinogenic aflatoxin is a persistent and serious agricultural problem causing disease and significant crop losses worldwide. The rachis (cob) is an important structure of maize ear ...

  2. Discovery of a novel aquaporin ZmPIP2-8 from southern corn rootworm infested maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A common paradigm of infestation by chewing insects is a jasmonic acid (JA) cascade that results in the induction of JA responsive genes. However examination of several maize genes induced by Southern corn rootworm (SCR) infestation, an insect that chews into and significantly damages maize roots, ...

  3. 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...

  4. 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

  5. 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

  6. Genetic dissection of maize phenology using an intraspecific introgression library

    PubMed Central

    2011-01-01

    Background Collections of nearly isogenic lines where each line carries a delimited portion of a donor source genome into a common recipient genetic background are known as introgression libraries and have already shown to be instrumental for the dissection of quantitative traits. By means of marker-assisted backcrossing, we have produced an introgression library using the extremely early-flowering maize (Zea mays L.) variety Gaspé Flint and the elite line B73 as donor and recipient genotypes, respectively, and utilized this collection to investigate the genetic basis of flowering time and related traits of adaptive and agronomic importance in maize. Results The collection includes 75 lines with an average Gaspé Flint introgression length of 43.1 cM. The collection was evaluated for flowering time, internode length, number of ears, number of nodes (phytomeres), number of nodes above the ear, number and proportion of nodes below the ear and plant height. Five QTLs for flowering time were mapped, all corresponding to major QTLs for number of nodes. Three additional QTLs for number of nodes were mapped. Besides flowering time, the QTLs for number of nodes drove phenotypic variation for plant height and number of nodes below and above the top ear, but not for internode length. A number of apparently Mendelian-inherited phenotypes were also observed. Conclusions While the inheritance of flowering time was dominated by the well-known QTL Vgt1, a number of other important flowering time QTLs were identified and, thanks to the type of plant material here utilized, immediately isogenized and made available for fine mapping. At each flowering time QTL, early flowering correlated with fewer vegetative phytomeres, indicating the latter as a key developmental strategy to adapt the maize crop from the original tropical environment to the northern border of the temperate zone (southern Canada), where Gaspé Flint was originally cultivated. Because of the trait differences

  7. 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

  8. 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

  9. Maize and resistant starch enriched breads reduce postprandial glycemic responses in rats.

    PubMed

    Brites, Carla M; Trigo, Maria J; Carrapiço, Belmira; Alviña, Marcela; Bessa, Rui J

    2011-04-01

    White wheat bread is a poor source of dietary fiber, typically containing less than 2%. A demand exists for the development of breads with starch that is slowly digestible or partially resistant to the digestive process. The utilization of maize flour and resistant starch is expected to reduce the release and absorption of glucose and, hence, lower the glycemic index of bread. This study was undertaken to investigate the hypothesis that a diet of maize bread, as produced and consumed in Portugal, would have beneficial metabolic effects on rats compared to white wheat bread. We also hypothesized that the effect of resistant starch on glycemic response could be altered by the use of different formulations and breadmaking processes for wheat and maize breads. Resistant starch (RS) was incorporated into formulations of breads at 20% of the inclusion rate of wheat and maize flours. Assays were conducted with male Wistar rats (n = 36), divided into four groups and fed either wheat bread, RS-wheat bread, maize bread, and RS-maize bread to evaluate feed intake, body weight gain, fecal pH, and postprandial blood glucose response (glycemic response). Blood triglycerides, total cholesterol concentrations, and liver weights were also determined. The maize bread group presented higher body weight gain and cholesterol level, lower fecal pH, and postprandial blood glucose response than the wheat bread group. The RS-wheat bread group showed significant reductions in feed intake, fecal pH, postprandial blood glucose response, and total cholesterol. The RS-maize group displayed significant reductions of body weight gain, fecal pH, and total cholesterol levels; however, for the glycemic response, only a reduction in fasting level was observed. These results suggest that maize bread has a lower glycemic index than wheat bread, and the magnitude of the effect of RS on glycemic response depends of type of bread. PMID:21530804

  10. 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.

  11. [Effects of phosphorus fertilization on leaf area index, biomass accumulation and allocation, and phosphorus use efficiency of intercropped maize].

    PubMed

    Chen, Yuan-Xue; Li, Han-Han; Zhou, Tao; Chen, Xin-Ping; Huang, Wei; Liu, Jing; Zhang, Chao-Chun; Xu, Kai-Wei

    2013-10-01

    A 2-year field experiment was conducted in 2011 and 2012 to investigate the effects of phosphorus (P) fertilization on the leaf area index (LAI), dry matter accumulation (DMA), and P use efficiency (PUE) of maize in wheat/maize/soybean intercropping system. Five P fertilization rates were installed, i.e., 0, 45, 90, 135, and 180 kg P2O5 x hm(-2) for wheat, marked as WP0, WP1, WP2, WP3, and WP4, respectively, and 0, 37.5, 75, 112.5, and 150 kg P2O5 x hm(-2) for maize, marked as MP0, MP1, MP2, MP3, and MP4, respectively. During the coexisted growth periods of wheat and maize, P fertilization increased the LAI, leaf area duration (LAD), and stem and leaf DMA of maize significantly. After the jointing stage of maize, the maize LAI, LAD, DMA, and crop growth rate (CGR) all decreased after an initial increase with the increasing P rate, with the maximum growth in treatment MP2 or MP3. During the reproductive stage of maize, the maize dry mass translocation from vegetative to reproductive organ increased with increasing P fertilization rate, and the grain yield of both maize and whole cropping system increased firstly and decreased then, with the maximum grain yield of maize and whole cropping system being 6588 and 11955 kg x hm(-2) in treatment P3, respectively. The P apparent recovery efficiency of maize was the highest (26.3%) in treatment MP2, being 82.6%, 38.4%, and 152.9% higher than that in MP1 (14.4%), MP3 (19.0%), and MP4 (10.4%), respectively. In sum, for the wheat/maize/soybean intercropping system, applying appropriate amount of P fertilizer could promote maize growth, alleviate the impact of wheat on maize, and consequently, increase the P apparent recovery efficiency of maize. In this study, the appropriate P fertilization rate was 75-112.5 kg P2O5 x hm(-2). PMID:24483073

  12. 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

  13. Combining Ability of Different Agronomic Traits and Yield Components in Hybrid Barley

    PubMed Central

    Lv, Chao; Guo, Baojian; Xu, Rugen

    2015-01-01

    Selection of parents based on their combining ability is an effective approach in hybrid breeding. In this study, eight maintainer lines and nine restorer lines were used to obtain 72 crosses for analyzing the general combining ability (GCA) and special combining ability (SCA) for seven agronomic and yield characters including plant height (PH), spike length excluding awns (SL), inter-node length (IL), spikes per plant (SP), thousand kernel weight (TKW), kernel weight per plant (KWP) and dry matter weight per plant (DWP). The results showed that GCA was significantly different among parents and SCA was also significantly different among crosses. The performance of hybrid was significantly correlated with the sum of female and male GCA (TGCA), SCA and heterosis. Hu1154 A, Mian684 A, 86F098 A, 8036 R and 8041 R were excellent parents with greater general combining ability. Five crosses, Hu1154 A×8032 R, Humai10 A×8040 R, Mian684 A×8037 R, Mian684 A×8041 R and 86F098 A×8037 R, showed superior heterosis for most characters. PMID:26061000

  14. Genetic analysis of carbon isotope discrimination and agronomic characters in a bread wheat cross.

    PubMed

    Ehdaie, B; Waines, J G

    1994-09-01

    Carbon isotope discrimination (Δ) has been suggested as a selection criterion to improve transpiration efficiency (W) in bread wheat (Triticum aestivum L.). Cultivars 'Chinese Spring' with low A (high W) and 'Yecora Rojo' with high Δ (low W) were crossed to develop F1, F2, BC1, and BC2 populations for genetic analysis of Δ and other agronomic characters under well-watered (wet) and water-stressed (dry) field conditions. Significant variation was observed among the generations for Δ only under the wet environment. Generation x irrigation interactions were not significant for Δ. Generation means analysis indicated that additive gene action is of primary importance in the expression of Δ under nonstress conditions. Dominance gene action was also detected for Δ, and the direction of dominance was toward higher values of Δ. The broad-sense and the narrow-sense heritabilities for Δ were 61 % and 57% under the wet conditions, but were 48% and 12% under the draughted conditions, respectively. The narrow-sense heritabilities for grain yield, above-ground dry matter, and harvest index were 36%, 39%, and 60% under the wet conditions and 21%, 44%, and 20% under dry conditions, respectively. The significant additive genetic variation and moderate estimate of the narrow-sense heritability observed for Δ indicated that selection under wet environments should be effective in changing Δ in spring bread wheat. PMID:24186257

  15. Statistical methods for texture analysis applied to agronomical images

    NASA Astrophysics Data System (ADS)

    Cointault, F.; Journaux, L.; Gouton, P.

    2008-02-01

    For activities of agronomical research institute, the land experimentations are essential and provide relevant information on crops such as disease rate, yield components, weed rate... Generally accurate, they are manually done and present numerous drawbacks, such as penibility, notably for wheat ear counting. In this case, the use of color and/or texture image processing to estimate the number of ears per square metre can be an improvement. Then, different image segmentation techniques based on feature extraction have been tested using textural information with first and higher order statistical methods. The Run Length method gives the best results closed to manual countings with an average error of 3%. Nevertheless, a fine justification of hypothesis made on the values of the classification and description parameters is necessary, especially for the number of classes and the size of analysis windows, through the estimation of a cluster validity index. The first results show that the mean number of classes in wheat image is of 11, which proves that our choice of 3 is not well adapted. To complete these results, we are currently analysing each of the class previously extracted to gather together all the classes characterizing the ears.

  16. 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. 

  17. 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

  18. The acrylamide problem: a plant and agronomic science issue.

    PubMed

    Halford, Nigel G; Curtis, Tanya Y; Muttucumaru, Nira; Postles, Jennifer; Elmore, J Stephen; Mottram, Donald S

    2012-05-01

    Acrylamide, a chemical that is probably carcinogenic in humans and has neurological and reproductive effects, forms from free asparagine and reducing sugars during high-temperature cooking and processing of common foods. Potato and cereal products are major contributors to dietary exposure to acrylamide and while the food industry reacted rapidly to the discovery of acrylamide in some of the most popular foods, the issue remains a difficult one for many sectors. Efforts to reduce acrylamide formation would be greatly facilitated by the development of crop varieties with lower concentrations of free asparagine and/or reducing sugars, and of best agronomic practice to ensure that concentrations are kept as low as possible. This review describes how acrylamide is formed, the factors affecting free asparagine and sugar concentrations in crop plants, and the sometimes complex relationship between precursor concentration and acrylamide-forming potential. It covers some of the strategies being used to reduce free asparagine and sugar concentrations through genetic modification and other genetic techniques, such as the identification of quantitative trait loci. The link between acrylamide formation, flavour, and colour is discussed, as well as the difficulty of balancing the unknown risk of exposure to acrylamide in the levels that are present in foods with the well-established health benefits of some of the foods concerned. PMID:22345642

  19. 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

  20. 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

  1. 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

  2. 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. PMID:26842991

  3. Development of maize starch granules

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize kernels of self-pollinated inbred line B73 harvested on various days after pollination (DAP) were subjected for starch granule development studies. Starch in endosperms was first observed on 6 DAP. A small amount of starch granules (<2% of dry weight) was found in the endosperm on 12 DAP. S...

  4. Maize Genetics and Genomics Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2007 report for MaizeGDB lists the new hires who will focus on curation/outreach and the genome sequence, respectively. Currently all sequence in the database comes from a PlantGDB pipeline and is presented with deep links to external resources such as PlantGDB, Dana Farber, GenBank, the Arizona...

  5. Flowering and Determinacy in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All plant organs are produced by meristems, groups of stem cells located in the tips of roots and shoots. Indeterminate meristems make an indefinite number of organs, whereas determinate meristems are consumed after making a specific number of organs. Maize is an ideal system to study the genetic co...

  6. 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

  7. 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

  8. 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

  9. Relationships of Helicoverpa armigera, Ostrinia nubilalis and Fusarium verticillioides on MON 810 Maize

    PubMed Central

    Darvas, Béla; Bánáti, Hajnalka; Takács, Eszter; Lauber, Éva; Szécsi, Árpád; Székács, András

    2011-01-01

    MON 810 maize was developed against Ostrinia nubilalis and is suggested to indirectly decrease Fusarium spp. infestation in maize ears. To evaluate this effect, co-occurrence of insect and fungal pests on MON 810 maize was studied. During 2009, exceptionally high maize ear infestation occurred in Julianna-major (Hungary). From investigation of some thousands of maize ears, the majority of the larval damage originated from Helicoverpa armigera larvae, while O. nubilalis larvae contributed significant damage only at a single plot. Fusarium verticillioides infection appeared only in a small portion (∼20–30%) of the insect damaged cobs. H. armigera and O. nubilalis larvae feeding on F. verticillioides mycelia can distribute its conidia with their fecal pellets. MON 810 maize showed 100% efficacy against O. nubilalis in the stem, but lower efficacy against O. nubilalis and H. armigera in maize ears. The ∼Cry1Ab toxin content of maize silk, the entry site of H. armigera, was lower than that in the leaves/stem/husk leaves of MON 810. Fusarium-infected MON 810 cobs are rarely found and only after larval damage by O. nubilalis. H. armigera larvae could not tolerate well F. verticillioides infected food and attempted to move out from the infected cobs. For further feeding they re-entered the maize ears through the 8–12 husk leaves, but in the case of the MON 810 variety, they usually could not reach the kernels. Apical damage on cobs resulted in only a minor (about one-tenth of the cob) decrease in yield. PMID:26467495

  10. Study on the weed-crop competition for nutrients in maize.

    PubMed

    Lehoczky, E; Reisinger, P

    2003-01-01

    Considering the effect of crop-weed competition the rate of weed growing, the competitiveness of the occurring weed species and the duration of competition are determining factors. Experiments were carried out on fields in order to collect data on the effect of early weed competition on maize, including the competition for nutrients and the possible rate of nutrient removal by weeds. From 7 sampling areas of the 9.2 ha field weeds and maize samples were collected 1 month after the sowing of maize. We determined the total numbers and the species numbers of weeds by plots. The removed plant species and maize were weighed then dried until the weight balance was reached. The samples were tested for N, P, K and Ca. Comparison was done with the weight and nutrient element content of maize plants taken from the treated, weed-free area. At the same time comparative analyses were made with the mass and nutrient contents of maize plants. There were 12 occurring weed species in this experiment. Based on the rate of weed cover the following species were dominant: Datum stramonium L., Cannabis sativa L., Amaranthus chlorostachis Willd., Chenopodium album L., Chenopodium hybridum L. Our experiments revealed that in the areas being likely to produce high weed populations and showing a considerable high nutrient removal by weeds, the competition between weed plants and maize occurs at an earlier stage of the vegetation period of maize than on fields with moderate weed populations. Weeds have utilised significant amount of nutrients which has been many fold of maize in case of unit area. PMID:15149132

  11. 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. PMID:26795400

  12. 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.

  13. Four descriptions: 'Mollicutes'; 'Corn stunt Spiroplasma'; 'Maize bushy stunt phytoplasma'; and, 'Maize redness'

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work includes four chapters, one describing mollicute pathogens of plants in general, and three describing specific mollicute pathogens of maize. Chapters describe the distribution, diseases, symptoms, vector epidemiology and detection of corn stunt spiroplasma, maize bushy stunt phytoplasma a...

  14. Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

    PubMed

    Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

    2016-04-01

    This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea maysL.) on growth and germination of succeeding crop wheat (Triticum aestivumL.) and associated weed (Avena fatuaL.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatuaL.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. PMID:24215059

  15. 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

  16. 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. PMID:22180940

  17. 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

  18. 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

  19. Reducing photoperiod response of tropical maize germplasm for use in Midwestern maize introgression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize Project (GEM) is a cooperative effort of USDA-ARS, public and private sector scientists to broaden the genetic diversity of maize germplasm. Tropical maize germplasm is an important source of alleles for biotic and abiotic stress resistance and numerous value-adde...

  20. 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...

  1. 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...

  2. 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

  3. 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

  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. PMID:24511684

  5. 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

  6. Metabolome-based genome-wide association study of maize kernel leads to novel biochemical insights

    PubMed Central

    Wen, Weiwei; Li, Dong; Li, Xiang; Gao, Yanqiang; Li, Wenqiang; Li, Huihui; Liu, Jie; Liu, Haijun; Chen, Wei; Luo, Jie; Yan, Jianbing

    2014-01-01

    Plants produce a variety of metabolites that have a critical role in growth and development. Here we present a comprehensive study of maize metabolism, combining genetic, metabolite and expression profiling methodologies to dissect the genetic basis of metabolic diversity in maize kernels. We quantify 983 metabolite features in 702 maize genotypes planted at multiple locations. We identify 1,459 significant locus–trait associations (P≤1.8 × 10−6) across three environments through metabolite-based genome-wide association mapping. Most (58.5%) of the identified loci are supported by expression QTLs, and some (14.7%) are validated through linkage mapping. Re-sequencing and candidate gene association analysis identifies potential causal variants for five candidate genes involved in metabolic traits. Two of these genes were further validated by mutant and transgenic analysis. Metabolite features associated with kernel weight could be used as biomarkers to facilitate genetic improvement of maize. PMID:24633423

  7. 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

  8. 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

  9. 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

  10. Association and Linkage Analysis of Aluminum Tolerance Genes in Maize

    PubMed Central

    Krill, Allison M.; Kirst, Matias; Kochian, Leon V.; Buckler, Edward S.; Hoekenga, Owen A.

    2010-01-01

    Background Aluminum (Al) toxicity is a major worldwide constraint to crop productivity on acidic soils. Al becomes soluble at low pH, inhibiting root growth and severely reducing yields. Maize is an important staple food and commodity crop in acidic soil regions, especially in South America and Africa where these soils are very common. Al exclusion and intracellular tolerance have been suggested as two important mechanisms for Al tolerance in maize, but little is known about the underlying genetics. Methodology An association panel of 282 diverse maize inbred lines and three F2 linkage populations with approximately 200 individuals each were used to study genetic variation in this complex trait. Al tolerance was measured as net root growth in nutrient solution under Al stress, which exhibited a wide range of variation between lines. Comparative and physiological genomics-based approaches were used to select 21 candidate genes for evaluation by association analysis. Conclusions Six candidate genes had significant results from association analysis, but only four were confirmed by linkage analysis as putatively contributing to Al tolerance: Zea mays AltSB like (ZmASL), Zea mays aluminum-activated malate transporter2 (ALMT2), S-adenosyl-L-homocysteinase (SAHH), and Malic Enzyme (ME). These four candidate genes are high priority subjects for follow-up biochemical and physiological studies on the mechanisms of Al tolerance in maize. Immediately, elite haplotype-specific molecular markers can be developed for these four genes and used for efficient marker-assisted selection of superior alleles in Al tolerance maize breeding programs. PMID:20376361

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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

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

    PubMed

    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

  17. 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

  18. 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.

  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. 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

  1. 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

  2. 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.

  3. 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.

  4. Transcriptomic analyses of maize ys1 and ys3 mutants reveal maize iron homeostasis.

    PubMed

    Nozoye, Tomoko; Nakanishi, Hiromi; Nishizawa, Naoko K

    2015-09-01

    To acquire iron (Fe), graminaceous plants secrete mugineic acid family phytosiderophores (MAs) (Takagi, 1976 [1]) through the MAs efflux transporter TOM1 (Nozoye et al., 2011 [2]) and take up Fe in the form of Fe(III)-MAs complexes through the Fe(III)-MAs transporter YS1 (Curie et al., 2001 [3]). Yellow stripe 1 (ys1) and ys3 are recessive mutants of maize (Zea mays L.) that result in symptoms typical of Fe deficiency, i.e., interveinal chlorosis of the leaves. The ys1 mutant is defective in the YS1 transporter and is therefore unable to take up Fe(III)-MAs complexes. While the ys3 mutant has been shown to be defective in MA release, the causative gene has not been identified. The objective of the present work was to identify the genes responsible for the ys1 and ys3 phenotypes, so as to extend our understanding of Fe homeostasis in maize by qRT-PCR. In agreement with previous reports, the expression level of YS1 was decreased in the ys1 mutant. Moreover, we identified that the expression level of a homolog of TOM1 in maize (ZmTOM1) was significantly decreased in the ys3 mutant. Here described the quality control and analysis that were performed on the dataset. The data is publicly available through the GEO database with accession number GSE44557. The interpretation and description of these data are included in a manuscript (Nozoye et al., 2013 [4]). PMID:26484234

  5. Comparative Genome Mapping of Sorghum and Maize

    PubMed Central

    Whitkus, R.; Doebley, J.; Lee, M.

    1992-01-01

    Linkage relationships were determined among 85 maize low copy number nuclear DNA probes and seven isozyme loci in an F(2) population derived from a cross of Sorghum bicolor ssp. bicolor X S. bicolor ssp. arundinaceum. Thirteen linkage groups were defined, three more than the 10 chromosomes of sorghum. Use of maize DNA probes to produce the sorghum linkage map allowed us to make several inferences concerning processes involved in the evolutionary divergence of the maize and sorghum genomes. The results show that many linkage groups are conserved between these two genomes and that the amount of recombination in these conserved linkage groups is roughly equivalent in maize and sorghum. Estimates of the proportions of duplicated loci suggest that a larger proportion of the loci are duplicated in the maize genome than in the sorghum genome. This result concurs with a prior estimate that the nuclear DNA content of maize is three to four times greater than that of sorghum. The pattern of conserved linkages between maize and sorghum is such that most sorghum linkage groups are composed of loci that map to two maize chromosomes. This pattern is consistent with the hypothesized ancient polyploid origin of maize and sorghum. There are nine cases in which locus order within shared linkage groups is inverted in sorghum relative to maize. These may have arisen from either inversions or intrachromosomal translocations. We found no evidence for large interchromosomal translocations. Overall, the data suggest that the primary processes involved in divergence of the maize and sorghum genomes were duplications (either by polyploidy or segmental duplication) and inversions or intrachromosomal translocations. PMID:1360933

  6. AGRONOMICS1: A New Resource for Arabidopsis Transcriptome Profiling1[W][OA

    PubMed Central

    Rehrauer, Hubert; Aquino, Catharine; Gruissem, Wilhelm; Henz, Stefan R.; Hilson, Pierre; Laubinger, Sascha; Naouar, Naira; Patrignani, Andrea; Rombauts, Stephane; Shu, Huan; Van de Peer, Yves; Vuylsteke, Marnik; Weigel, Detlef; Zeller, Georg; Hennig, Lars

    2010-01-01

    Transcriptome profiling has become a routine tool in biology. For Arabidopsis (Arabidopsis thaliana), the Affymetrix ATH1 expression array is most commonly used, but it lacks about one-third of all annotated genes present in the reference strain. An alternative are tiling arrays, but previous designs have not allowed the simultaneous analysis of both strands on a single array. We introduce AGRONOMICS1, a new Affymetrix Arabidopsis microarray that contains the complete paths of both genome strands, with on average one 25mer probe per 35-bp genome sequence window. In addition, the new AGRONOMICS1 array contains all perfect match probes from the original ATH1 array, allowing for seamless integration of the very large existing ATH1 knowledge base. The AGRONOMICS1 array can be used for diverse functional genomics applications such as reliable expression profiling of more than 30,000 genes, detection of alternative splicing, and chromatin immunoprecipitation coupled to microarrays (ChIP-chip). Here, we describe the design of the array and compare its performance with that of the ATH1 array. We find results from both microarrays to be of similar quality, but AGRONOMICS1 arrays yield robust expression information for many more genes, as expected. Analysis of the ATH1 probes on AGRONOMICS1 arrays produces results that closely mirror those of ATH1 arrays. Finally, the AGRONOMICS1 array is shown to be useful for ChIP-chip experiments. We show that heterochromatic H3K9me2 is strongly confined to the gene body of target genes in euchromatic chromosome regions, suggesting that spreading of heterochromatin is limited outside of pericentromeric regions. PMID:20032078

  7. [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

  8. 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

  9. Usefulness of Multiparental Populations of Maize (Zea mays L.) for Genome-Based Prediction

    PubMed Central

    Lehermeier, Christina; Krämer, Nicole; Bauer, Eva; Bauland, Cyril; Camisan, Christian; Campo, Laura; Flament, Pascal; Melchinger, Albrecht E.; Menz, Monica; Meyer, Nina; Moreau, Laurence; Moreno-González, Jesús; Ouzunova, Milena; Pausch, Hubert; Ranc, Nicolas; Schipprack, Wolfgang; Schönleben, Manfred; Walter, Hildrun; Charcosset, Alain; Schön, Chris-Carolin

    2014-01-01

    The efficiency of marker-assisted prediction of phenotypes has been studied intensively for different types of plant breeding populations. However, one remaining question is how to incorporate and counterbalance information from biparental and multiparental populations into model training for genome-wide prediction. To address this question, we evaluated testcross performance of 1652 doubled-haploid maize (Zea mays L.) lines that were genotyped with 56,110 single nucleotide polymorphism markers and phenotyped for five agronomic traits in four to six European environments. The lines are arranged in two diverse half-sib panels representing two major European heterotic germplasm pools. The data set contains 10 related biparental dent families and 11 related biparental flint families generated from crosses of maize lines important for European maize breeding. With this new data set we analyzed genome-based best linear unbiased prediction in different validation schemes and compositions of estimation and test sets. Further, we theoretically and empirically investigated marker linkage phases across multiparental populations. In general, predictive abilities similar to or higher than those within biparental families could be achieved by combining several half-sib families in the estimation set. For the majority of families, 375 half-sib lines in the estimation set were sufficient to reach the same predictive performance of biomass yield as an estimation set of 50 full-sib lines. In contrast, prediction across heterotic pools was not possible for most cases. Our findings are important for experimental design in genome-based prediction as they provide guidelines for the genetic structure and required sample size of data sets used for model training. PMID:25236445

  10. 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.

  11. 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.

  12. Evaluation of five ab initio gene prediction programs for the discovery of maize genes.

    PubMed

    Yao, Hong; Guo, Ling; Fu, Yan; Borsuk, Lisa A; Wen, Tsui-Jung; Skibbe, David S; Cui, Xiangqin; Scheffler, Brian E; Cao, Jun; Emrich, Scott J; Ashlock, Daniel A; Schnable, Patrick S

    2005-02-01

    Five ab initio programs (FGENESH, GeneMark.hmm, GENSCAN, GlimmerR and Grail) were evaluated for their accuracy in predicting maize genes. Two of these programs, GeneMark.hmm and GENSCAN had been trained for maize; FGENESH had been trained for monocots (including maize), and the others had been trained for rice or Arabidopsis. Initial evaluations were conducted using eight maize genes (gl8a, pdc2, pdc3, rf2c, rf2d, rf2e1, rth1, and rth3) of which the sequences were not released to the public prior to conducting this evaluation. The significant advantage of this data set for this evaluation is that these genes could not have been included in the training sets of the prediction programs. FGENESH yielded the most accurate and GeneMark.hmm the second most accurate predictions. The five programs were used in conjunction with RT-PCR to identify and establish the structures of two new genes in the a1-sh2 interval of the maize genome. FGENESH, GeneMark.hmm and GENSCAN were tested on a larger data set consisting of maize assembled genomic islands (MAGIs) that had been aligned to ESTs. FGENESH, GeneMark.hmm and GENSCAN correctly predicted gene models in 773, 625, and 371 MAGIs, respectively, out of the 1353 MAGIs that comprise data set 2. PMID:15830133

  13. A transposable element in a NAC gene is associated with drought tolerance in maize seedlings.

    PubMed

    Mao, Hude; Wang, Hongwei; Liu, Shengxue; Li, Zhigang; Yang, Xiaohong; Yan, Jianbing; Li, Jiansheng; Tran, Lam-Son Phan; Qin, Feng

    2015-01-01

    Drought represents a major constraint on maize production worldwide. Understanding the genetic basis for natural variation in drought tolerance of maize may facilitate efforts to improve this trait in cultivated germplasm. Here, using a genome-wide association study, we show that a miniature inverted-repeat transposable element (MITE) inserted in the promoter of a NAC gene (ZmNAC111) is significantly associated with natural variation in maize drought tolerance. The 82-bp MITE represses ZmNAC111 expression via RNA-directed DNA methylation and H3K9 dimethylation when heterologously expressed in Arabidopsis. Increasing ZmNAC111 expression in transgenic maize enhances drought tolerance at the seedling stage, improves water-use efficiency and induces upregulation of drought-responsive genes under water stress. The MITE insertion in the ZmNAC111 promoter appears to have occurred after maize domestication and spread among temperate germplasm. The identification of this MITE insertion provides insight into the genetic basis for natural variation in maize drought tolerance. PMID:26387805

  14. [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. PMID:20707114

  15. A transposable element in a NAC gene is associated with drought tolerance in maize seedlings

    PubMed Central

    Mao, Hude; Wang, Hongwei; Liu, Shengxue; Li, Zhigang; Yang, Xiaohong; Yan, Jianbing; Li, Jiansheng; Tran, Lam-Son Phan; Qin, Feng

    2015-01-01

    Drought represents a major constraint on maize production worldwide. Understanding the genetic basis for natural variation in drought tolerance of maize may facilitate efforts to improve this trait in cultivated germplasm. Here, using a genome-wide association study, we show that a miniature inverted-repeat transposable element (MITE) inserted in the promoter of a NAC gene (ZmNAC111) is significantly associated with natural variation in maize drought tolerance. The 82-bp MITE represses ZmNAC111 expression via RNA-directed DNA methylation and H3K9 dimethylation when heterologously expressed in Arabidopsis. Increasing ZmNAC111 expression in transgenic maize enhances drought tolerance at the seedling stage, improves water-use efficiency and induces upregulation of drought-responsive genes under water stress. The MITE insertion in the ZmNAC111 promoter appears to have occurred after maize domestication and spread among temperate germplasm. The identification of this MITE insertion provides insight into the genetic basis for natural variation in maize drought tolerance. PMID:26387805

  16. Future carbon dioxide concentration decreases canopy evapotranspiration and soil water depletion by field-grown maize.

    PubMed

    Hussain, Mir Zaman; Vanloocke, Andy; Siebers, Matthew H; Ruiz-Vera, Ursula M; Cody Markelz, R J; Leakey, Andrew D B; Ort, Donald R; Bernacchi, Carl J

    2013-05-01

    Maize, in rotation with soybean, forms the largest continuous ecosystem in temperate North America, therefore changes to the biosphere-atmosphere exchange of water vapor and energy of these crops are likely to have an impact on the Midwestern US climate and hydrological cycle. As a C4 crop, maize photosynthesis is already CO2 -saturated at current CO2 concentrations ([CO2 ]) and the primary response of maize to elevated [CO2 ] is decreased stomatal conductance (gs ). If maize photosynthesis is not stimulated in elevated [CO2 ], then reduced gs is not offset by greater canopy leaf area, which could potentially result in a greater ET reduction relative to that previously reported in soybean, a C3 species. The objective of this study is to quantify the impact of elevated [CO2 ] on canopy energy and water fluxes of maize (Zea mays). Maize was grown under ambient and elevated [CO2 ] (550 μmol mol(-1) during 2004 and 2006 and 585 μmol mol(-1) during 2010) using Free Air Concentration Enrichment (FACE) technology at the SoyFACE facility in Urbana, Illinois. Maize ET was determined using a residual energy balance approach based on measurements of sensible (H) and soil heat fluxes, and net radiation. Relative to control, elevated [CO2 ] decreased maize ET (7-11%; P < 0.01) along with lesser soil moisture depletion, while H increased (25-30 W m(-2) ; P < 0.01) along with higher canopy temperature (0.5-0.6 °C). This reduction in maize ET in elevated [CO2 ] is approximately half that previously reported for soybean. A partitioning analysis showed that transpiration contributed less to total ET for maize compared to soybean, indicating a smaller role of stomata in dictating the ET response to elevated [CO2 ]. Nonetheless, both maize and soybean had significantly decreased ET and increased H, highlighting the critical role of elevated [CO2 ] in altering future hydrology and climate of the region that is extensively cropped with these species. PMID:23505040

  17. 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.

  18. 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...

  19. 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...

  20. 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...

  1. Aflatoxin accumulation in a maize diallel cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins, produced by the fungus Aspergillus flavus, occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimin...

  2. Germplasm Enhancement of Maize (GEM) Project Overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Germplasm Enhancement of Maize Project (GEM) is a collaborative effort of public and private sector researchers to broaden and enhance the maize germplasm base. The GEM Project has cooperators from 26 private companies, 17 Universities, 7 USDA-ARS Research Units, 1 NGO, and 12 international pub...

  3. MaizeGDB's New Data Types, Resources, and Activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecul...

  4. Functional Allelic Variation at Key Photoperiod Response QTL in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical maize represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. We tested ...

  5. MaizeGDB's new data types, resources, and activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the Maize Genetics and Genomics Database. Available at MaizeGDB are diverse data that support maize research including maps, gene product information, loci and their various alleles, phenotypes (both naturally occurring and as a result of directed mutagenesis), stocks, sequences, molecul...

  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. Occupational Rhinoconjunctivitis due to Maize in a Snack Processor: A Cross-Reactivity Study Between Lipid Transfer Proteins From Different Cereals and Peach.

    PubMed

    Guillen, Daiana; Barranco, Pilar; Palacín, Arantxa; Quirce, Santiago

    2014-09-01

    We report the case of a snack processor who developed occupational rhinoconjunctivitis due to maize brand exposure during the extrusion process, and who experienced abdominal pain upon drinking beer. The allergens implicated and the cross-reactivity between non-specific lipid transfer proteins (LTPs) from different cereals and peach were investigated. Skin prick tests and specific IgE to cereal flours, pulmonary functions tests and specific conjunctival and inhalation challenges to maize extract were performed. In vitro studies included IgE immunoblotting and ELISA inhibition assays. Skin prick tests with maize flour, maize brand and wheat flour extracts were positive, whereas serum specific IgE was positive only to maize flour. Specific inhalation challenge (SIC) to maize flour did not elicit an asthmatic reaction; however, conjunctival challenge test with the same extract was positive. Patient's serum recognized IgE-binding bands in the maize and beer extracts corresponding to LTPs. In the ELISA inhibition assays, a significant degree of allergenic cross-reactivity was found between maize and beer LTPs, whereas no cross-reactivity was observed between maize LTP and wheat and peach LTPs. PMID:25229007

  8. 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.

  9. Co-infection and disease severity of Ohio Maize dwarf mosaic virus and Maize chlorotic dwarf virus strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two major maize viruses have been reported in the United States: Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV). These viruses co-occur in regions where maize is grown such that co-infections are likely. Co-infection of different strains of MCDV is also observed frequently...

  10. 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

  11. Genetic and morphometric analysis of cob architecture and biomass related traits in the intermated B73xMo17 recombinant inbred lines of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Expected future cellulosic ethanol production increases the demand for biomass in the U.S. Corn Belt. With low nutritious value, low nitrogen content, and compact biomass, maize cobs can provide a significant amount of cellulosic materials. The value of maize cobs depends on cob architecture, chemic...

  12. 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

  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. 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.

  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. PMID:27145588

  17. 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...

  18. 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...

  19. 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...

  20. Disease evaluations and agronomic traits of advanced peanut breeding lines in 2013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 21 peanut cultivars and high-oleic advanced breeding lines were evaluated in small field plots in 2013 for agronomic traits (crop value, yield, seed grade, and characteristics) and resistance to diseases (Sclerotinia blight, southern blight, and Pythium and Rhizoctonia pod rot). Among th...

  1. 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 ...

  2. Effects of Agronomic and Conservation Management Practices On Organic Matter and Associated Properties in Claypan Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic matter plays several important roles in the biogeochemistry of soil and impacts the sustainability and profitability of agroecosystems. Retention and transformation of soil organic matter (SOM) are affected by agronomic and conservation management practices. The primary objective of this stu...

  3. Agronomic options for improving rainfall-use efficiency of crops in dryland farming systems.

    PubMed

    Turner, Neil C

    2004-11-01

    Yields of dryland (rainfed) wheat in Australia have increased steadily over the past century despite rainfall being unchanged, indicating that the rainfall-use efficiency has increased. Analyses suggest that at least half of the increase in rainfall-use efficiency can be attributed to improved agronomic management. Various methods of analysing the factors influencing dryland yields and rainfall-use efficiency, such as simple rules and more complex models, are presented and the agronomic factors influencing water use, water-use efficiency, and harvest index of crops are discussed. The adoption of agronomic procedures such as minimum tillage, appropriate fertilizer use, improved weed/disease/insect control, timely planting, and a range of rotation options, in conjunction with new cultivars, has the potential to increase the yields and rainfall-use efficiency of dryland crops. It is concluded that most of the agronomic options for improving rainfall-use efficiency in rainfed agricultural systems decrease water losses by soil evaporation, runoff, throughflow, deep drainage, and competing weeds, thereby making more water available for increased water use by the crop. PMID:15361527

  4. ANIMAL WASTE UTILIZATION ON CROPLAND AND PASTURELAND. A MANUAL FOR EVALUATING AGRONOMIC AND ENVIRONMENTAL EFFECTS

    EPA Science Inventory

    Engineering and agronomic techniques to predict and control the volume of nutrients and chemical oxygen demand leaving the application sites, caused by the application of animal wastes, are described. Methodology was developed to enable the user to identify the pollutant loads fo...

  5. Agronomic performance and genetic characterization of sugarcane transformed for resistance to sugarcane yellow leaf virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Sugar Cane Yellow Leaf Virus (SCYLV) is widespread in Florida, and SCYLV resistance in the Canal Point (CP) sugarcane population is limited. The objectives of this study were to 1) evaluate the agronomic performance of two transgenic lines transformed for SCYLV resistance (6-1, 6-2) compared to ...

  6. 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...

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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

  12. [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

  13. Evolution of DUF1313 family members across plant species and their association with maize photoperiod sensitivity.

    PubMed

    Li, Jia; Hu, Erliang; Chen, Xueying; Xu, Jie; Lan, Hai; Li, Chuan; Hu, Yaodong; Lu, Yanli

    2016-05-01

    Proteins of the DUF1313 family contain a highly conserved domain and are only found in plants; they play important roles in most plant functions. In this study, 269 DUF1313 genes from 81 photoautotrophic species were identified; they were classified into three major types based on the amino acid substitutions in the conserved region: IARV, I(S/T/F)(K/R)V, and IRRV. Phylogenic tree constructed from 51 DUF1313 genes from graminoids revealed three clades: A, B1, and B2. Clade B1 was found to have undergone episodic positive selection after a gene duplication event and included four amino acid sites under positive selection. The association between DUF1313 family members and traits investigated in maize indicated that three of four genes (GRMZM2G025646, GRMZM5G877647, GRMZM2G359322, and GRMZM2G382774) were associated with the target traits such as days to silking, days to tasselling, and plant height. The nucleotide diversity of the most primitive and highly conserved DUF1313 gene, ELF4-like4, was the highest in Tripsacum and the lowest in maize. Tajima's D and Fu and Li's D tests revealed that significant purifying selection had occurred in the coding sequence region of this DUF1313 gene in teosinte and maize. No significant signal was detected in the 5'-untranslated region of this gene in each of the three species (maize, teosinte, and Tripsacum) or in any gene regions of Tripsacum. Phylogenetic analyses revealed that the 103 accessions of maize, teosinte, and Tripsacum can be grouped into four clades based on the ELF4-like4 gene sequence similarity. Thus, this gene can be used to determine the relationships between maize and its relatives, and the DUF1313 family members and alleles identified in this study might be valuable genetic resources for molecular marker-assisted breeding in maize. PMID:26772990

  14. 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

  15. 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

  16. 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

  17. 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. PMID:19226848

  18. [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

  19. 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

  20. 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

  1. 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. PMID:17929890

  2. Potential for Nitrogen Fixation in Maize Genotypes in Brazil

    PubMed Central

    Von Bülow, Joachim F. W.; Döbereiner, Johanna

    1975-01-01

    N2 fixation in field-grown maize (Zea mays L.) plants was estimated by a nondestructive acetylene reduction method which permitted the plants to continue growing and produce seeds. Samples from six areas revealed mean nitrogenase activities of 74-2167 nmol of C2H4/(g of dry roots × hr) for 10 plants. Among 276 S1 lines planted in two field experiments, 17 lines were selected for further nitrogenase activity assays after prescreening. Variability within lines was high but significant differences among lines were obtained in one experiment. The best lines showed mean nitrogenase activities of 2026, 2315, and 7124 nmol of C2H4/(g of dry roots × hr), whereas the original cultivar reduced only 313 nmol. The highest value approaches the nitrogenase activity of soybean. If the theoretical 3:1 (C2H4/N2 reduced) conversion factor is used, a potential daily N2 fixation of 2 kg of N2/hectare can be calculated. Periodic sampling within a brachytic maize cultivar revealed that maximum nitrogenase activity occurred at about the 75% silking stage. Soil effects also were pronounced. N2-fixing Spirillum sp. could be isolated from all active root pieces when they were surface sterilized. These organisms appear to be primarily responsible for root nitrogenase activity in maize. PMID:16592251

  3. Early maize agriculture and interzonal interaction in southern Peru.

    PubMed

    Perry, Linda; Sandweiss, Daniel H; Piperno, Dolores R; Rademaker, Kurt; Malpass, Michael A; Umire, Adán; de la Vera, Pablo

    2006-03-01

    Over the past decade, increasing attention to the recovery and identification of plant microfossil remains from archaeological sites located in lowland South America has significantly increased knowledge of pre-Columbian plant domestication and crop plant dispersals in tropical forests and other regions. Along the Andean mountain chain, however, the chronology and trajectory of plant domestication are still poorly understood for both important indigenous staple crops such as the potato (Solanum sp.) and others exogenous to the region, for example, maize (Zea mays). Here we report the analyses of plant microremains from a late preceramic house (3,431 +/- 45 to 3,745 +/- 65 14C bp or approximately 3,600 to 4,000 calibrated years bp) in the highland southern Peruvian site of Waynuna. Our results extend the record of maize by at least a millennium in the southern Andes, show on-site processing of maize into flour, provide direct evidence for the deliberate movement of plant foods by humans from the tropical forest to the highlands, and confirm the potential of plant microfossil analysis in understanding ancient plant use and migration in this region. PMID:16511492

  4. Hardness methods for testing maize kernels.

    PubMed

    Fox, Glen; Manley, Marena

    2009-07-01

    Maize is a highly important crop to many countries around the world, through the sale of the maize crop to domestic processors and subsequent production of maize products and also provides a staple food to subsistance farms in undeveloped countries. In many countries, there have been long-term research efforts to develop a suitable hardness method that could assist the maize industry in improving efficiency in processing as well as possibly providing a quality specification for maize growers, which could attract a premium. This paper focuses specifically on hardness and reviews a number of methodologies as well as important biochemical aspects of maize that contribute to maize hardness used internationally. Numerous foods are produced from maize, and hardness has been described as having an impact on food quality. However, the basis of hardness and measurement of hardness are very general and would apply to any use of maize from any country. From the published literature, it would appear that one of the simpler methods used to measure hardness is a grinding step followed by a sieving step, using multiple sieve sizes. This would allow the range in hardness within a sample as well as average particle size and/or coarse/fine ratio to be calculated. Any of these parameters could easily be used as reference values for the development of near-infrared (NIR) spectroscopy calibrations. The development of precise NIR calibrations will provide an excellent tool for breeders, handlers, and processors to deliver specific cultivars in the case of growers and bulk loads in the case of handlers, thereby ensuring the most efficient use of maize by domestic and international processors. This paper also considers previous research describing the biochemical aspects of maize that have been related to maize hardness. Both starch and protein affect hardness, with most research focusing on the storage proteins (zeins). Both the content and composition of the zein fractions affect

  5. 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

  6. Significant Treasures.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    1999-01-01

    Provides a crossword puzzle with an answer key corresponding to the book entitled "Significant Treasures/Tresors Parlants" that is filled with color and black-and-white prints of paintings and artifacts from 131 museums and art galleries as a sampling of the 2,200 such Canadian institutions. (CMK)

  7. 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

  8. Rhizobium etli maize populations and their competitiveness for root colonization.

    PubMed

    Rosenblueth, Mónica; Martínez-Romero, Esperanza

    2004-05-01

    Rhizobium etli, which normally forms nitrogen-fixing nodules on Phaseolus vulgaris (common bean), is a natural maize endophyte. The genetic diversity of R. etli strains from bulk soil, bean nodules, the maize rhizosphere, the maize root, and inside stem tissue in traditional fields where maize is intercropped with P. vulgaris-beans was analyzed. Based on plasmid profiles and alloenzymes, it was determined that several R. etli types were preferentially encountered as putative maize endophytes. Some of these strains from maize were more competitive maize-root colonizers than other R. etli strains from the rhizosphere or from bean nodules. The dominant and highly competitive strain Ch24-10 was the most tolerant to 6-methoxy-2-benzoxazolinone (MBOA), a maize antimicrobial compound that is inhibitory to some bacteria and fungi. The R. tropici strain CIAT899, successfully used as inoculant of P. vulgaris, was also found to be a competitive maize endophyte in inoculation experiments. PMID:15024554

  9. Antimicrobial activity of pyrrocidines from Acremonium zeae against endophytes and pathogens of maize.

    PubMed

    Wicklow, Donald T; Poling, Stephen M

    2009-01-01

    Acremonium zeae produces pyrrocidines A and B, which are polyketide-amino acid-derived antibiotics, and is recognized as a seedborne protective endophyte of maize which augments host defenses against microbial pathogens causing seedling blights and stalk rots. Pyrrocidine A displayed significant in vitro activity against Aspergillus flavus and Fusarium verticillioides in assays performed using conidia as inoculum, with pyrrocidine A being more active than B. In equivalent assays performed with conidia or hyphal cells as inoculum, pyrrocidine A revealed potent activity against major stalk and ear rot pathogens of maize, including F. graminearum, Nigrospora oryzae, Stenocarpella (Diplodia) maydis, and Rhizoctonia zeae. Pyrrocidine A displayed significant activity against seed-rotting saprophytes A. flavus and Eupenicillium ochrosalmoneum, as well as seed-infecting colonists of the phylloplane Alternaria alternata, Cladosporium cladosporioides, and Curvularia lunata, which produces a damaging leaf spot disease. Protective endophytes, including mycoparasites which grow asymptomatically within healthy maize tissues, show little sensitivity to pyrrocidines. Pyrrocidine A also exhibited potent activity against Clavibacter michiganense subsp. nebraskense, causal agent of Goss's bacterial wilt of maize, and Bacillus mojaviense and Pseudomonas fluorescens, maize endophytes applied as biocontrol agents, but were ineffective against the wilt-producing bacterium Pantoea stewartii. PMID:19055442

  10. The nutritive value of stackburned yellow maize for livestock: tests in vitro and in broiler chicks.

    PubMed

    Panigrahi, S; Bestwick, L A; Davis, R H; Wood, C D

    1996-07-01

    Difference in the nutritive value of four grades of stackburned yellow maize, obtained from a single storage unit in Mozambique, were examined. Samples were analysed for chemical composition, and subjected to the following in vitro assays for estimating digestibility: total dietary fibre and pancreatin for non-ruminants, and gas production using sheep rumen fluid for ruminant livestock. Samples were also fed to broiler chicks at 600 g/kg diet in a growth trial. There were no significant differences in crude protein contents of the maize samples, but there was evidence for the development of Maillard reaction products. Detectable amino acids were lower in discoloured maize, with decreases of 52% in lysine, 35% in arginine, and 15% in glycine concentration in the most severely discoloured sample compared with control. Total starch, reducing sugar, acid-detergent fibre and amylase-neutral-detergent fibre values increased, while total non-reducing sugar content decreased with increased discolouration. Total dietary fibre and pancreatin assays indicated a lowering in digestibility of maize with increasing discolouration. Weight gain of chicks (P = 0.0228), efficiency of feed utilization (P = 0.0009) and the metabolizable energy value of diets decreased (P < 0.0001) with increasing stackburn discolouration. There were no significant effects on N retention of diets. In vitro fermentation using sheep rumen fluid showed a linear decrease in gas production with increasing maize discolouration, indicating a reduction in rumen degradability with stackburn. PMID:8774220

  11. [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

  12. 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. PMID:26926794

  13. 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

  14. 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

  15. 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.

  16. [Soil nitrogen mineralization and its prediction in winter wheat-summer maize rotation system].

    PubMed

    Ju, Xiaotang; Liu, Xuejun; Zhang, Fusuo

    2003-12-01

    The mineralization of soil nitrogen in winter wheat-summer maize growth season was studied with field experiment, and its prediction was made by interval leached aerial incubation combined with first-order dynamic model. The results showed that the amount of soil mineralized nitrogen had a large variation among years and crops. The soil nitrogen mineralization was lower in winter wheat growth season than in summer maize growth season, resulted in the yield increment of summer maize being not significant with increasing nitrogen fertilization rate. The amount of soil mineralized nitrogen occupied 31%-60% of the total nitrogen uptake by winter wheat and 62%-108% by summer maize. It was understandable why crop yield (especially summer maize) was not significantly response to applied nitrogen fertilizer. The amount of soil mineralized nitrogen decreased with increasing soil nitrogen supply. The mineralization was positive in normal nitrogen supply range(0-300 kg N.hm-2). The first order dynamic model could only predict the whole trend of mineralization in growth season, but could not reflect its variation in some growth stages. The role of the model was still important in view of the prediction of nitrogen mineralization before sowing. PMID:15031925

  17. Different Effects of Transgenic Maize and Nontransgenic Maize on Nitrogen-Transforming Archaea and Bacteria in Tropical Soils

    PubMed Central

    Cotta, Simone Raposo; Dias, Armando Cavalcante Franco; Marriel, Ivanildo Evódio; Andreote, Fernando Dini; van Elsas, Jan Dirk

    2014-01-01

    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

  18. 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

  19. Association Mapping for Enhancing Maize Genetic Improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Association mapping through linkage disequilibrium (LD) analysis is a powerful tool for the dissection of complex agronomic traits and for the identification of alleles that can contribute to the enhancement of a target trait. With the developments of high throughput genotyping techniques and advanc...

  20. 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

  1. 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

  2. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas.

    PubMed

    Ortiz, Carlos S; Richards, Casey; Terry, Ashlee; Parra, Joselyn; Shim, Won-Bo

    2015-09-01

    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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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 ...

  9. Molecular Genetics of Mitochondrial Biogenesis in Maize.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mitochondrial genome encodes proteins essential for mitochondrial respiration and ATP synthesis. Nuclear gene products, however, are required for the expression of mitochondrial genes and the elaboration of functional mitochondrial protein complexes. We are exploiting a unique collection of maiz...

  10. 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

  11. Open chromatin reveals the functional maize genome.

    PubMed

    Rodgers-Melnick, Eli; Vera, Daniel L; Bass, Hank W; Buckler, Edward S

    2016-05-31

    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

  12. A European perspective on maize history.

    PubMed

    Tenaillon, Maud Irène; Charcosset, Alain

    2011-03-01

    Maize was domesticated at least 8700 years ago in the highlands of Mexico. Genome-wide studies have greatly contributed to shed light into the diffusion of maize through the Americas from its center of origin. Also the presence of two European introductions in southern and northern Europe is now established. Such a spread was accompanied by an extreme diversification, and adaptation to the long days and low temperatures of temperate climates has been a key step in maize evolution. Linkage mapping and association mapping have successfully led to the identification of a handful set of the genetic factors that have contributed to maize adaptation, opening the way to new discoveries. Ultimately, these alleles will contribute to sustain breeding efforts to meet the new challenges raised by the evolution of mankind. PMID:21377617

  13. 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

  14. 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

  15. Can Transgenic Maize Affect Soil Microbial Communities?

    PubMed Central

    Mulder, Christian; Wouterse, Marja; Raubuch, Markus; Roelofs, Willem; Rutgers, Michiel

    2006-01-01

    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

  16. The Effect of Feeding Bt MON810 Maize to Pigs for 110 Days on Intestinal Microbiota

    PubMed Central

    Buzoianu, Stefan G.; Walsh, Maria C.; Rea, Mary C.; O’Sullivan, Orla; Crispie, Fiona; Cotter, Paul D.; Ross, R. Paul; Gardiner, Gillian E.; Lawlor, Peadar G.

    2012-01-01

    Objective To assess the effects of feeding Bt MON810 maize to pigs for 110 days on the intestinal microbiota. Methodology/Principal Findings Forty male pigs (∼40 days old) were blocked by weight and litter ancestry and assigned to one of four treatments; 1) Isogenic maize-based diet for 110 days (Isogenic); 2) Bt maize-based diet (MON810) for 110 days (Bt); 3) Isogenic maize-based diet for 30 days followed by a Bt maize-based diet for 80 days (Isogenic/Bt); 4) Bt maize-based diet for 30 days followed by an isogenic maize-based diet for 80 days (Bt/Isogenic). Enterobacteriaceae, Lactobacillus and total anaerobes were enumerated in the feces using culture-based methods on days 0, 30, 60 and 100 of the study and in ileal and cecal digesta on day 110. No differences were found between treatments for any of these counts at any time point. The relative abundance of cecal bacteria was also determined using high-throughput 16 S rRNA gene sequencing. No differences were observed in any bacterial taxa between treatments, with the exception of the genus Holdemania which was more abundant in the cecum of pigs fed the isogenic/Bt treatment compared to pigs fed the Bt treatment (0.012 vs 0.003%; P≤0.05). Conclusions/Significance Feeding pigs a Bt maize-based diet for 110 days did not affect counts of any of the culturable bacteria enumerated in the feces, ileum or cecum. Neither did it influence the composition of the cecal microbiota, with the exception of a minor increase in the genus Holdemania. As the role of Holdemania in the intestine is still under investigation and no health abnormalities were observed, this change is not likely to be of clinical significance. These results indicate that feeding Bt maize to pigs in the context of its influence on the porcine intestinal microbiota is safe. PMID:22574106

  17. 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.

  18. Climate change and maize yield in Iowa

    DOE PAGESBeta

    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

  19. 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. PMID:27219116

  20. 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

  1. Effect of dietary fiber and starch on fecal composition in preschool children consuming maize, amaranth, or cassava flours.

    PubMed

    Hamaker, B R; Rivera, K; Morales, E; Graham, G G

    1991-07-01

    Metabolic balance studies were carried out in young children fed diets based on maize, amaranth, or cassava flours and in corresponding casein controls. Dietary fiber intakes were 22.2, 20.5, and 9.0 g/day for the maize, amaranth, and cassava groups, respectively. Fecal energy losses at least doubled in all test diets when compared with the corresponding controls and could generally be accounted for by recovered fiber in the feces. Fecal starch was also a significant contributor to fecal energy in the cassava group. All cassava fiber was recovered in the feces, whereas only 48.4 and 16.3% were recovered from ingested maize and amaranth. 2,6-Diaminopimelic acid (DAPA), an indicator of bacterial mass, was highest in the cassava group. Expired breath hydrogen was highest for those consuming maize or cassava. Resistant starch may have been responsible for the high DAPA and breath hydrogen values in the cassava group. PMID:1656007

  2. Genome-wide association study using whole-genome sequencing rapidly identifies new genes influencing agronomic traits in rice.

    PubMed

    Yano, Kenji; Yamamoto, Eiji; Aya, Koichiro; Takeuchi, Hideyuki; Lo, Pei-Ching; Hu, Li; Yamasaki, Masanori; Yoshida, Shinya; Kitano, Hidemi; Hirano, Ko; Matsuoka, Makoto

    2016-08-01

    A genome-wide association study (GWAS) can be a powerful tool for the identification of genes associated with agronomic traits in crop species, but it is often hindered by population structure and the large extent of linkage disequilibrium. In this study, we identified agronomically important genes in rice using GWAS based on whole-genome sequencing, followed by the screening of candidate genes based on the estimated effect of nucleotide polymorphisms. Using this approach, we identified four new genes associated with agronomic traits. Some genes were undetectable by standard SNP analysis, but we detected them using gene-based association analysis. This study provides fundamental insights relevant to the rapid identification of genes associated with agronomic traits using GWAS and will accelerate future efforts aimed at crop improvement. PMID:27322545

  3. AEPAT: SOFTWARE FOR ASSESSING AGRONOMIC AND ENVIRONMENTAL PERFORMANCE OF MANAGEMENT PRACTICES IN LONG-TERM AGROECOSYSTEM EXPERIMENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approaches to assess the effects of management practices on agroecosystem functions are needed to determine the relative sustainability of agricultural management systems. This paper describes a computer program designed to assess the relative sustainability of management practices using agronomic ...

  4. Comparison of Gene Expressions of Maize Kernel Pathogenesis-Related Proteins in Different Maize Genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are carcinogenic mycotoxins produced by the fungus Aspergillus flavus during infection of various grain crops including maize (Zea mays). Contamination of maize with aflatoxins has been shown to be exasperated by late season drought stress. Previous studies have identified numerous resist...

  5. The Other NPGS Maize Collection – A Rich Source of Maize Genetic Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize collection at the North Central Regional Plant Introduction Station, Ames, IA is comprised of over 18,300 accessions from all over the world. Of these, 16,000 are maize accessions with population level genetic diversity and over 2,000 are inbred lines with little segregation. The collectio...

  6. 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, ...

  7. MaizeGDB: The Maize Model Organism Database for Basic, Translational, and Applied Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2001, maize became the number one production crop in the world (with over 614 million tons produced; http://faostat.fao.org). 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, its...

  8. 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 ...

  9. 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...

  10. Effects of Silicon on Photosynthetic Characteristics of Maize (Zea mays L.) on Alluvial Soil

    PubMed Central

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

    2014-01-01

    The objectives of the study were to determine the effects of silicon on photosynthetic characteristics of maize on alluvial soil, including total chlorophyll contents, photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (E), and intercellular CO2 concentration (Ci) using the method of field experiment, in which there were five levels (0, 45, 90, 150, and 225 kg·ha−1) of silicon supplying. The results showed that certain doses of silicon fertilizers can be used successfully in increasing the values of total chlorophyll contents, Pn, and gs and decreasing the values of E and Ci of maize leaves, which meant that photosynthetic efficiency of maize was significantly increased in different growth stages by proper doses of Si application on alluvial soil, and the optimal dose of Si application was 150 kg·ha−1. Our results indicated that silicon in proper amounts can be beneficial in increasing the photosynthetic ability of maize, which would be helpful for the grain yield and growth of maize. PMID:24982984

  11. Effect of Compost and Maize Cultivars on Plant-parasitic Nematodes.

    PubMed

    McSorley, R; Gallaher, R N

    1997-12-01

    Effects of yard waste compost and maize (Zea mays) cultivar on population densities of plant-parasitic nematodes were examined in four experiments in north Florida. In one experiment, eight maize cultivars were evaluated; the other three experiments involved split-plot designs with compost treatments as main plots and maize cultivars as subplots. The three compost treatments used in these experiments were: 269 mt/ha of a yard-waste compost applied to the soil surface as a mulch, 269 mt/ha of compost incolporated into the soil, and an unamended control. No interactions between compost treatment and cultivar occurred in any experiment. Effects of compost treatment on Mesocriconema spp., Meloidogyne incognita, and Pratylenchus spp. were inconsistent, whereas significant effects of compost on population densities of Paratrichodorus minor were found on four of six sampling occasions. Cultivar affected final population densities (Pf) of M. incognita. In two tests, Pf of M. incognita on a Florida subtropical experimental hybrid (Howard III) were only 36% and 23% of Pf on the standard tropical hybrid (Pioneer Brand X304C). In an integrated approach to management of nematodes in maize, the effects of compost amendment and culfivar choice acted independently. Apparently, cultivar choice is more important than amendment with yard waste compost for management of M. incognita population levels in a maize rotation crop. PMID:19274277

  12. 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

  13. 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

  14. Efficacy of Microwave-Heating during Alkaline Processing of Fumonisin-Contaminated Maize

    PubMed Central

    MENDEZ-ALBORES, Abraham; CARDENAS-RODRIGUEZ, Denisse Anelem; VAZQUEZ-DURAN, Alma

    2014-01-01

    Abstract Background Fumonisins (a family of foodborne carcinogenic mycotoxins) cause health hazards to humans and animals in developing countries, and has also economic implications. Therefore, the efficacy of a novel environmental friendly nixtamalization procedure to make tortillas (the main staple food for the Mexican population) was investigated. Methods Maize contaminated with 2136.67 ng/g total fumonisins was processed into tortillas, starting with maize grits mixed with water and calcium hydroxide that was cooked in a microwave field at 2.45 GHz during 3.75 min, and steeped 3.5 h at room temperature. The steeped maize grits (nixtamal) was stone-ground into masa (maize dough), which was then used to make tortillas. Total fumonisin content was determined using monoclonal antibody columns. Results Masa contained 1998.33 ng/g total fumonisins, which represents 6.5% toxin reduction. Nevertheless, fumonisin concentration was reduced significantly in tortillas (up to 985.33 ng/g) due to the cooking process, corresponding to a cumulative toxin degradation of 54%. Tortillas were below the maximum tolerated level, considering the European Union regulatory limit for fumonisins in maize (1000 ng/g). The physicochemical and technological properties of tortillas were also considered within the acceptable margins of quality. Conclusion Microwave nixtamalization was not a feasible method to reduce fumonisin content in masa to acceptable levels; however, an effective extra-reduction occurred when masa was baking into tortillas. PMID:26060737

  15. 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

  16. 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

  17. 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

  18. Fertigation effect of distillery effluent on agronomical practices of Trigonella foenum-graecum L. (Fenugreek).

    PubMed

    Vinod Kumar; Chopra, A K

    2012-03-01

    The fertigation effect of distillery effluents concentrations such as 5%, 10%, 25%, 50%, 75% and 100% were studied on Trigonella foenu-graecu (Pusa early bunching) along with control (bore well water). On irrigation of soil with different effluents up to 90 days of harvesting, it was observed that there was a significant effect on moisture content (P < 0.001), EC, pH, Cl(-), total organic carbon (TOC), HCO₃⁻, CO₃⁻², Na(+), K(+), Ca(2+), Mg(2+), Fe(2+), TKN, NO₃²⁻, PO₄³⁻, and SO₄²⁻ (P < 0.0001) and insignificant effect on WHC and bulk density (P > 0.05).There was no significant change in the soil texture of the soil. Among various concentrations of effluent irrigation, the irrigation with 100% effluent concentration decreased pH (16.66%) and increased moisture content (30.82%), EC(84.13%), Cl(-) (292.37%), TOC (4311.61%), HCO₃⁻ (27.76%), CO₃⁻² (32.63%), Na +) (273%), K(+) (31.59%), Ca(2+) (729.76%), Mg(2+) (740.47%), TKN (1723.32%), NO₃²⁻ (98.02%), PO₄³⁻ (337.79%), and SO₄²⁻ (77.78%), Fe(2+) (359.91%), Zn (980.48%), Cu (451.51%), Cd (3033.33%), Pb (2350.00%), and Cr (2375.00%) in the soil. The agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, chlorophyll content, LAI, crop yield, and HI of T. foenum-graecum were recorded to be in increasing order at low concentration of the effluent, i.e., from 5% to 50% and in decreasing order at higher effluent concentration, i.e., from 75% to 100% as compared to control. The enrichment factor of various heavy metals was ordered for soil Cd>Cr> Pb>Zn>Cu>Fe and for T. foenum-graecum plants Pb>Cr>Cd>Cu>Zn>Fe after irrigation with distillery effluent. PMID:21499700

  19. 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

  20. 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

  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. Genome-wide characterization of cis-acting DNA targets reveals the transcriptional regulatory framework of opaque2 in maize.

    PubMed

    Li, Chaobin; Qiao, Zhenyi; Qi, Weiwei; Wang, Qian; Yuan, Yue; Yang, Xi; Tang, Yuanping; Mei, Bing; Lv, Yuanda; Zhao, Han; Xiao, Han; Song, Rentao

    2015-03-01

    Opaque2 (O2) is a transcription factor that plays important roles during maize endosperm development. Mutation of the O2 gene improves the nutritional value of maize seeds but also confers pleiotropic effects that result in reduced agronomic quality. To reveal the transcriptional regulatory framework of O2, we studied the transcriptome of o2 mutants using RNA sequencing (RNA-Seq) and determined O2 DNA binding targets using chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq). The RNA-Seq analysis revealed 1605 differentially expressed genes (DEGs) and 383 differentially expressed long, noncoding RNAs. The DEGs cover a wide range of functions related to nutrient reservoir activity, nitrogen metabolism, stress resistance, etc. ChIP-Seq analysis detected 1686 O2 DNA binding sites distributed over 1143 genes. Overlay of the RNA-Seq and ChIP-Seq results revealed 35 O2-modulated target genes. We identified four O2 binding motifs; among them, TGACGTGG appears to be the most conserved and strongest. We confirmed that, except for the 16- and 18-kD zeins, O2 directly regulates expression of all other zeins. O2 directly regulates two transcription factors, genes linked to carbon and amino acid metabolism and abiotic stress resistance. We built a hierarchical regulatory model for O2 that provides an understanding of its pleiotropic biological effects. PMID:25691733

  4. 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

  5. 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

  6. Multi-trait BLUP model indicates sorghum hybrids with genetic potential for agronomic and nutritional traits.

    PubMed

    Almeida Filho, J E; Tardin, F D; Guimarães, J F R; Resende, M D V; Silva, F F; Simeone, M L; Menezes, C B; Queiroz, V A V

    2016-01-01

    The breeding of sorghum, Sorghum bicolor (L.) Moench, aimed at improving its nutritional quality, is of great interest, since it can be used as a highly nutritive alternative food source and can possibly be cultivated in regions with low rainfall. The objective of the present study was to evaluate the potential and genetic diversity of grain-sorghum hybrids for traits of agronomic and nutritional interest. To this end, the traits grain yield and flowering, and concentrations of protein, potassium, calcium, magnesium, sulfur, iron, manganese, and zinc in the grain were evaluated in 25 grain-sorghum hybrids, comprising 18 experimental hybrids of Embrapa Milho e Sorgo and seven commercial hybrids. The genetic potential was analyzed by a multi-trait best linear unbiased prediction (BLUP) model, and cluster analysis was accomplished by squared Mahalanobis distance using the predicted genotypic values. Hybrids 0306037 and 0306034 stood out in the agronomic evaluation. The hybrids with agronomic prominence, however, did not stand out for the traits related to the nutritional quality of the grain. Three clusters were formed from the dendrogram obtained with the unweighted pair group method with arithmetic mean method. From the results of the genotypic BLUP and the analysis of the dendrogram, hybrids 0577337, 0441347, 0307651, and 0306037 were identified as having the potential to establish a population that can aggregate alleles for all the evaluated traits of interest. PMID:26985915

  7. 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.

  8. Identification of a bioactive Bowman-Birk inhibitor from an insect-resistant early maize inbred.

    PubMed

    Johnson, Eric T; Skory, Christopher; Dowd, Patrick F

    2014-06-18

    Breeding of maize, Zea mays, has improved insect resistance, but the genetic and biochemical basis of many of these improvements is unknown. Maize oligonucleotide microarrays were utilized to identify differentially expressed genes in leaves of three maize inbreds, parents Oh40B and W8 and progeny Oh43, developed in the 1940s. Oh43 had enhanced leaf resistance to corn earworm larvae, Helicoverpa zea, and fall armyworm larvae, Spodoptera frugiperda, compared to one or both parents. Among ca. 100 significantly differentially expressed genes, expression of a Bowman-Birk trypsin inhibitor (BBI) gene was at least ca. 8-fold higher in Oh43 than in either parent. The Oh43 BBI gene was expressed as a recombinant protein. Purified BBI inhibited trypsin and the growth of fall armyworm larvae when added to insect diet. These experiments indicate that comparative gene expression analysis combined with insect resistance measurements of early inbreds can identify previously unrecognized resistance genes. PMID:24869634

  9. Influence of western corn rootworm (Coleoptera: Chrysomelidae) larval injury on yield of different types of maize.

    PubMed

    Urías-López, M A; Meinke, L J

    2001-02-01

    Two field experiments were conducted in 1995-1996 to determine if there are common yield responses among maize hybrids to larval western corn rootworm, Diabrotica virgifera virgifera LeConte injury. Three yellow dent hybrids, five white food grade dent hybrids, and a popcorn hybrid were included in the study. The minimum level of rootworm injury as measured by root damage ratings (3.2-4.2) that significantly reduced yield was similar across the hybrids included in the study. However, the pattern of yield response to different rootworm injury levels varied among hybrids. This suggests that maize hybrids may inherently differ in their ability to tolerate rootworm injury and partition biomass in response to injury and other stresses. The complex interaction among hybrid, level of injury, and other stresses suggests that a common western corn rootworm injury-yield relationship may not exist within maize. PMID:11233098

  10. Leaf transpiration efficiency of some drought-resistant maize lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field measurements of leaf gas exchange in maize often indicate stomatal conductances higher than required to provide substomatal carbon dioxide concentrations saturating to photosynthesis. Thus maize leaves often operate at lower transpiration efficiency (TE) than potentially achievable for specie...

  11. Cadmium induces acidosis in maize root cells.

    PubMed

    Nocito, Fabio Francesco; Espen, Luca; Crema, Barbara; Cocucci, Maurizio; Sacchi, Gian Attilio

    2008-01-01

    * Cadmium (Cd) stress increases cell metabolic demand for sulfur, reducing equivalents, and carbon skeletons, to sustain phytochelatin biosynthesis for Cd detoxification. In this condition the induction of potentially acidifying anaplerotic metabolism in root tissues may be expected. For these reasons the effects of Cd accumulation on anaplerotic metabolism, glycolysis, and cell pH control mechanisms were investigated in maize (Zea mays) roots. * The study compared root apical segments, excised from plants grown for 24 h in a nutrient solution supplemented, or not, with 10 microM CdCl(2), using physiological, biochemical and (31)P-nuclear magnetic resonance (NMR) approaches. * Cadmium exposure resulted in a significant decrease in both cytosolic and vacuolar pH of root cells and in a concomitant increase in the carbon fluxes through anaplerotic metabolism leading to malate biosynthesis, as suggested by changes in dark CO2 fixation, metabolite levels and enzyme activities along glycolysis, and mitochondrial alternative respiration capacity. This scenario was accompanied by a decrease in the net H(+) efflux from the roots, probably related to changes in plasma membrane permeability. * It is concluded that anaplerotic metabolism triggered by Cd detoxification processes might lead to an imbalance in H(+) production and consumption, and then to cell acidosis. PMID:18537888

  12. Invasive species and climate change: an agronomic perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increase in the introduction of new, invasive pests (pathogens, fungi, weeds and insects) represents a significant challenge to USDA in maintaining a secure, safe and adequate food supply. Although invasive biology has become the focus of a number of research efforts, no systematic evaluation o...

  13. 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

  14. 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

  15. 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

  16. 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.

  17. Scenario analysis on the adaptation of different maize varieties to future climate change in Northeast China

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    Based on gridded meteorological data for the period 1981-2100 from the RegCM3 regional model, the changing trends of climatic resources in Northeast China are analyzed, and the distributions of maize varieties are accordingly adjusted. In order to explore the effects of different adaptation countermeasures on climatic productivity and meteorological suitability in the future, maize cultivars with resistance to high temperatures and/or drought are selected. The results show that, in the future, there is likely to be a significant increase in thermal resources, and potential atmospheric evaporation will increase correspondingly. Meanwhile, radiation is predicted to increase significantly during 2041-2070 in the growing season. However, changes in precipitation are unlikely to be sufficient enough to offset the intensification in atmospheric evaporation caused by the temperature increase. Water resources and high temperatures are found to be the two major factors constraining grain yield. The results also show that the warming climate will be favorable for maize production where thermal resources are already limited, such as in central and northern Heilongjiang Province and eastern Jilin Province; while in areas that are already relatively warm, such as Liaoning Province, climatic productivity will be reduced. The climatic productivity and the meteorological suitability of maize are found to improve when the planting of resistant varieties is modeled. The utilization of agricultural climatic resources through the adaptation countermeasures of maize varieties is to increase obviously with time. Specifically, maize with drought-resistant properties will have a marked influence on meteorological suitability during 2011-2070, with suitable areas expanding. During 2071-2100, those maize varieties with their upper limit of optimum temperature and maximum temperature increased by 2°, or water requirement reduced to 94%, or upper limit of optimum temperature and maximum

  18. Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

    PubMed

    Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

    2002-01-01

    Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system. PMID:12083257

  19. Canopy warming caused photosynthetic acclimation and reduced seed yield in maize grown at ambient and elevated [CO2 ].

    PubMed

    Ruiz-Vera, Ursula M; Siebers, Matthew H; Drag, David W; Ort, Donald R; Bernacchi, Carl J

    2015-11-01

    Rising atmospheric CO2 concentration ([CO2 ]) and attendant increases in growing season temperature are expected to be the most important global change factors impacting production agriculture. Although maize is the most highly produced crop worldwide, few studies have evaluated the interactive effects of elevated [CO2 ] and temperature on its photosynthetic physiology, agronomic traits or biomass, and seed yield under open field conditions. This study investigates the effects of rising [CO2 ] and warmer temperature, independently and in combination, on maize grown in the field throughout a full growing season. Free-air CO2 enrichment (FACE) technology was used to target atmospheric [CO2 ] to 200 μmol mol(-1) above ambient [CO2 ] and infrared heaters to target a plant canopy increase of 3.5 °C, with actual season mean heating of ~2.7 °C, mimicking conditions predicted by the second half of this century. Photosynthetic gas-exchange parameters, leaf nitrogen and carbon content, leaf water potential components, and developmental measurements were collected throughout the season, and biomass and yield were measured at the end of the growing season. As predicted for a C4 plant, elevated [CO2 ] did not stimulate photosynthesis, biomass, or yield. Canopy warming caused a large shift in aboveground allocation by stimulating season-long vegetative biomass and decreasing reproductive biomass accumulation at both CO2 concentrations, resulting in decreased harvest index. Warming caused a reduction in photosynthesis due to down-regulation of photosynthetic biochemical parameters and the decrease in the electron transport rate. The reduction in seed yield with warming was driven by reduced photosynthetic capacity and by a shift in aboveground carbon allocation away from reproduction. This field study portends that future warming will reduce yield in maize, and this will not be mitigated by higher atmospheric [CO2 ] unless appropriate adaptation traits can be introduced

  20. Effect of Selected Volatiles on Two Stored Pests: The Fungus Fusarium verticillioides and the Maize Weevil Sithophilus zeamais.

    PubMed

    Zunino, María P; Herrera, Jimena M; Pizzolitto, Romina P; Rubinstein, Héctor R; Zygadlo, Julio A; Dambolena, José S

    2015-09-01

    New agronomic practices and technology enabled Argentina a larger production of cereal grains, reaching a harvest yield of 26.5 million metric tons of maize, of which, about 40% was exported. However, much of the maize production is lost annually by the attack of fungi and insects (2.6 million tons). In this study, the antifungal effect of selected volatiles on Fusarium verticillioides, its mycotoxin production, and the repellent and insecticidal activities against the weevill Sithophilus zeamais, an insect vector of F. verticillioides, were evaluated. The compounds tested were (2E)-2-hexenal, (2E)-2-nonenal, (2E,6Z)-2,6-nonadienal, 1-pentanol, 1-hexanol, 1-butanol, 3-methyl-1-butanol, pentanal, 2-decanone, and 3-decanone, which occur in the blend of volatile compounds emitted by various cereal grains. The most active antifungals were the aldehydes (2E)-2-nonenal, (2E)-2-hexenal, and (2E,6Z)-2,6-nonadienal (minimum inhibitory concentration values of <0.03, 0.06, and 0.06 mM, respectively). The occurrence of fumonisin B1 also was prevented because these compounds completely inhibited fungal growth. The best insecticidal fumigant activities against the maize weevil were shown by 2-decanone and 3-decanone (lethal concentration ≤ 54.6 μL/L (<0.28 mM)). Although, all tested compounds showed repellent activity against S. zeamais at a concentration of 4 μL/L, (2E,6Z)-2,6-nonadienal was the most active repellent compound. These results demonstrate the potential of (2E,6Z)-2,6-nonadienal to be used as a natural alternative to synthetic pesticides on F. verticillioides and S. zeamais. PMID:26257042

  1. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are often 1 to 2 Mg/ha lower than those achieved when maize is grown in rotation with soybean in the U.S. Midwest. One factor contributing to this difference is the release of phytotoxic compounds as the previous year’s maize residue decomposes. Based on laboratory results sh...

  2. Biochar mitigation of allelopathy induced yield loss in continuous maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous maize yields are limited by the release of phytotoxic compounds as the previous year’s maize residue decomposes. We tested the hypothesis that soil biochar applications could help mitigate maize autotoxicity and the associated yield depression. Eighteen small field plots (23.7 m2) were es...

  3. Formation of Elongated Starch Granules in High-amylose Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEMS-0067 maize starch contains up to 32% elongated starch granules much higher than amylose-extender (ae) single-mutant maize starch (~7%) and normal (non-mutant) maize starch (0%). These elongated granules are highly resistant to enzymatic hydrolysis at 95-100 C, which function as resistant starc...

  4. Mapping QTL Contributing to SCMV Resistance in Tropical Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane mosaic virus (SCMV) has been increasing in importance as a maize disease in Brazil. In this study, were mapped and characterized quantitative trait loci (QTL) associated to resistance to SCMV in a maize population consisting of 150 F2:3 families from the cross between two tropical maize i...

  5. Quantitative trait loci for resistance to Maize rayado fino virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize rayado fino virus (MRFV) causes one of the most important virus diseases of maize in regions of Mexico, Central and South America, where it causes moderate to severe yield losses. The virus is found from the southern United States. to northern Argentina where its vector, the maize leafhopper D...

  6. MaizeGDB: everything old is new again! [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The focus of genetic, genomic, and breeding research evolves over time, making it necessary to continually redefine the paradigm for data access and data analysis tools. Here we report the reinvention of MaizeGDB, the maize genetics and genomics database, to meet maize researchers’ ever changing nee...

  7. Resistance of Tripsacorn-introgressed maize lines to Sitophilus zeamais

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is one of the major pests of maize worldwide. We tested one Tripsacorn-introgressed inbred maize line and 42 hybrid combinations between eleven public inbred lines and 16 different Tripsacorn-introgressed inbreds for resis...

  8. Comprehensive genotyping of the USA national maize inbred seed bank

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The germplasm bank at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa, preserves maize inbred lines from breeding programs from all over the world, including some of the key lines from the breeding history of maize. We genotyped 2,815 maize inbred accessions, mo...

  9. Characterization of high temperature tolerance mechanisms in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High temperature, combined with drought, is a major environmental stress that greatly depresses yield and reduces the quality of maize plants in the Southern Plains area. Maize inbred lines vary greatly in thermotolerance based on field observations. Two contrasting maize inbred lines, B76, heat-to...

  10. Gluten-free spaghetti with unripe plantain, chickpea and maize: physicochemical, texture and sensory properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this investigation was to determine the physicochemical, textural and sensorial characteristics of gluten-free spaghetti elaborated with unripe plantain, chickpea and maize flours. Luminosity (L*) of the uncooked gluten-free spaghetti was not significantly different from control sampl...

  11. MICROARRAY ANALYSIS OF MAIZE OPAQUE2 IN DEVELOPING ENDOSPERMS OF EIGHT INBRED LINES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Opaque2 (o2) mutation can significantly improve the protein nutritional quality of corn kernels by increasing the lysine content of maize endosperm. Since this discovery, it has been the subject of intense research. Studies conducted over the past 40 years have revealed that the o2 mutation redu...

  12. Fitness costs of resistance to Cry3Bb1 maize by Western Corn Rootworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crops producing toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely planted to manage insect pests, including western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), a significant pest of maize. The evolution of resistance would diminish the ef...

  13. Effects of elevated CO2 on maize defense against mycotoxigenic Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elevated atmospheric carbon dioxide concentration ([CO2]) increased maize susceptibility to Fusarium verticillioides stalk rot. Even though the pathogen biomass accumulated to significantly higher levels at double ambient [CO2] (2x[CO2]), the projected [CO2] concentration to occur at the end of this...

  14. Antimicrobial Activity of Pyrrocidines from Acremonium zeae against Endophytes and Pathogens of Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acremonium zeae produces pyrrocidines A and B, polyketide-amino acid-derived antibiotics, and is recognized as a seed-borne protective endophyte of maize which augments host defenses against microbial pathogens causing seedling blights and stalk rots. Pyrrocidine A displayed significant in vitro ac...

  15. Induced defenses in maize following attack by the European corn borer (Ostrinia nubilalis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the course of the past two decades, insect pests such as the European corn borer (Ostrinia nubilalis) annually resulted in losses to US maize production exceeding one billion dollars. Despite the global significance of O. nubilalis and other stem borers, relatively little is known about the nat...

  16. Identification and mapping of new sources of resistance to aflatoxin accumulation in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize susceptibility to ear rot and aflatoxin accumulation by Aspergillus flavus has caused significant economic losses for farmers in the United States over the past 30 years. Aflatoxin outbreaks are generally associated with high temperatures and low moisture levels common to the southern US. To...

  17. Dynamic Maize Responses to Aphid Feeding Are Revealed by a Time Series of Transcriptomic and Metabolomic Assays1[OPEN

    PubMed Central

    Tzin, Vered; Fernandez-Pozo, Noe; Richter, Annett; Schmelz, Eric A.; Schoettner, Matthias; Schäfer, Martin; Ahern, Kevin R.; Meihls, Lisa N.; Kaur, Harleen; Huffaker, Alisa; Mori, Naoki; Degenhardt, Joerg; Mueller, Lukas A.; Jander, Georg

    2015-01-01

    As a response to insect attack, maize (Zea mays) has inducible defenses that involve large changes in gene expression and metabolism. Piercing/sucking insects such as corn leaf aphid (Rhopalosiphum maidis) cause direct damage by acquiring phloem nutrients as well as indirect damage through the transmission of plant viruses. To elucidate the metabolic processes and gene expression changes involved in maize responses to aphid attack, leaves of inbred line B73 were infested with corn leaf aphids for 2 to 96 h. Analysis of infested maize leaves showed two distinct response phases, with the most significant transcriptional and metabolic changes occurring in the first few hours after the initiation of aphid feeding. After 4 d, both gene expression and metabolite profiles of aphid-infested maize reverted to being more similar to those of control plants. Although there was a predominant effect of salicylic acid regulation, gene expression changes also indicated prolonged induction of oxylipins, although not necessarily jasmonic acid, in aphid-infested maize. The role of specific metabolic pathways was confirmed using Dissociator transposon insertions in maize inbred line W22. Mutations in three benzoxazinoid biosynthesis genes, Bx1, Bx2, and Bx6, increased aphid reproduction. In contrast, progeny production was greatly decreased by a transposon insertion in the single W22 homolog of the previously uncharacterized B73 terpene synthases TPS2 and TPS3. Together, these results show that maize leaves shift to implementation of physical and chemical defenses within hours after the initiation of aphid feeding and that the production of specific metabolites can have major effects in maize-aphid interactions. PMID:26378100

  18. Production and in vitro fermentation of soluble, non-digestible, feruloylated oligo- and polysaccharides from maize and wheat brans.

    PubMed

    Yang, Junyi; Maldonado-Gómez, María X; Hutkins, Robert W; Rose, Devin J

    2014-01-01

    High-pressure hydrothermal treatment of cereal bran results in fragmentation of the cell wall, releasing soluble, non-digestible, feruloylated oligo- and polysaccharides (FOPS), which may be beneficial to gut health. The objectives of this study were to (1) determine treatment temperatures for production of FOPS from maize bran and wheat bran and (2) determine the fermentation properties of partially purified FOPS from maize bran and wheat bran. FOPS were produced by heating bran and water (10%, w/v) in a high-pressure stirred reactor until the slurry reached 160-200 °C (in 10 °C increments). Final temperatures of 190 °C for maize bran and 200 °C for wheat bran resulted in the highest release of FOPS (49 and 50% of starting non-starch polysaccharide, respectively). Partial purification with ion exchange and dialysis resulted in a final product containing 63 and 57% total carbohydrate and 49 and 30% FOPS, respectively (other carbohydrate was starch). Following in vitro digestion (to remove starch), in vitro fermentation revealed that wheat FOPS were more bifidogenic than maize FOPS. However, maize FOPS led to continual production of short-chain fatty acid (SCFA), resulting in the highest SCFA and butyrate production at the end of the fermentation. In addition, maize FOPS showed significantly higher antioxidant activity than wheat FOPS. This study identified a process to produce FOPS from maize bran and wheat bran and showed that, considering the overall beneficial effects, FOPS from maize bran may exhibit enhanced benefits on gut health compared to those of wheat bran. PMID:24359228

  19. Dynamic Maize Responses to Aphid Feeding Are Revealed by a Time Series of Transcriptomic and Metabolomic Assays.

    PubMed

    Tzin, Vered; Fernandez-Pozo, Noe; Richter, Annett; Schmelz, Eric A; Schoettner, Matthias; Schäfer, Martin; Ahern, Kevin R; Meihls, Lisa N; Kaur, Harleen; Huffaker, Alisa; Mori, Naoki; Degenhardt, Joerg; Mueller, Lukas A; Jander, Georg

    2015-11-01

    As a response to insect attack, maize (Zea mays) has inducible defenses that involve large changes in gene expression and metabolism. Piercing/sucking insects such as corn leaf aphid (Rhopalosiphum maidis) cause direct damage by acquiring phloem nutrients as well as indirect damage through the transmission of plant viruses. To elucidate the metabolic processes and gene expression changes involved in maize responses to aphid attack, leaves of inbred line B73 were infested with corn leaf aphids for 2 to 96 h. Analysis of infested maize leaves showed two distinct response phases, with the most significant transcriptional and metabolic changes occurring in the first few hours after the initiation of aphid feeding. After 4 d, both gene expression and metabolite profiles of aphid-infested maize reverted to being more similar to those of control plants. Although there was a predominant effect of salicylic acid regulation, gene expression changes also indicated prolonged induction of oxylipins, although not necessarily jasmonic acid, in aphid-infested maize. The role of specific metabolic pathways was confirmed using Dissociator transposon insertions in maize inbred line W22. Mutations in three benzoxazinoid biosynthesis genes, Bx1, Bx2, and Bx6, increased aphid reproduction. In contrast, progeny production was greatly decreased by a transposon insertion in the single W22 homolog of the previously uncharacterized B73 terpene synthases TPS2 and TPS3. Together, these results show that maize leaves shift to implementation of physical and chemical defenses within hours after the initiation of aphid feeding and that the production of specific metabolites can have major effects in maize-aphid interactions. PMID:26378100

  20. Investigation of the effect of genotype and agronomic conditions on metabolomic profiles of selected strawberry cultivars with different sensitivity to environmental stress.

    PubMed

    Akhatou, Ikram; González-Domínguez, Raúl; Fernández-Recamales, Ángeles

    2016-04-01

    Strawberry is one of the most economically important and widely cultivated fruit crops across the world, so that there is a growing need to develop new analytical methodologies for the authentication of variety and origin, as well as the assessment of agricultural and processing practices. In this work, an untargeted metabolomic strategy based on gas chromatography mass spectrometry (GC-MS) combined with multivariate statistical techniques was used for the first time to characterize the primary metabolome of different strawberry cultivars and to study metabolite alterations in response to multiple agronomic conditions. For this purpose, we investigated three varieties of strawberries with different sensitivity to environmental stress (Camarosa, Festival and Palomar), cultivated in soilless systems using various electrical conductivities, types of coverage and substrates. Metabolomic analysis revealed significant alterations in primary metabolites between the three strawberry cultivars grown under different crop conditions, including sugars (fructose, glucose), organic acids (malic acid, citric acid) and amino acids (alanine, threonine, aspartic acid), among others. Therefore, it could be concluded that GC-MS based metabolomics is a suitable tool to differentiate strawberry cultivars and characterize metabolomic changes associated with environmental and agronomic conditions. PMID:26841267

  1. 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

  2. The maize (Zea mays ssp. mays var. B73) genome encodes 33 members of the purple acid phosphatase family.

    PubMed

    González-Muñoz, Eliécer; Avendaño-Vázquez, Aida-Odette; Montes, Ricardo A Chávez; de Folter, Stefan; Andrés-Hernández, Liliana; Abreu-Goodger, Cei; Sawers, Ruairidh J H

    2015-01-01

    Purple acid phosphatases (PAPs) play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73) reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members. PMID:26042133

  3. The maize (Zea mays ssp. mays var. B73) genome encodes 33 members of the purple acid phosphatase family

    PubMed Central

    González-Muñoz, Eliécer; Avendaño-Vázquez, Aida-Odette; Montes, Ricardo A. Chávez; de Folter, Stefan; Andrés-Hernández, Liliana; Abreu-Goodger, Cei; Sawers, Ruairidh J. H.

    2015-01-01

    Purple acid phosphatases (PAPs) play an important role in plant phosphorus nutrition, both by liberating phosphorus from organic sources in the soil and by modulating distribution within the plant throughout growth and development. Furthermore, members of the PAP protein family have been implicated in a broader role in plant mineral homeostasis, stress responses and development. We have identified 33 candidate PAP encoding gene models in the maize (Zea mays ssp. mays var. B73) reference genome. The maize Pap family includes a clear single-copy ortholog of the Arabidopsis gene AtPAP26, shown previously to encode both major intracellular and secreted acid phosphatase activities. Certain groups of PAPs present in Arabidopsis, however, are absent in maize, while the maize family contains a number of expansions, including a distinct radiation not present in Arabidopsis. Analysis of RNA-sequencing based transcriptome data revealed accumulation of maize Pap transcripts in multiple plant tissues at multiple stages of development, and increased accumulation of specific transcripts under low phosphorus availability. These data suggest the maize PAP family as a whole to have broad significance throughout the plant life cycle, while highlighting potential functional specialization of individual family members. PMID:26042133

  4. Improved tolerance of maize (Zea mays L.) to heavy metals by colonization of a dark septate endophyte (DSE) Exophiala pisciphila.

    PubMed

    Li, T; Liu, M J; Zhang, X T; Zhang, H B; Sha, T; Zhao, Z W

    2011-02-15

    Dark septate endophytes (DSE) are ubiquitous and abundant in stressful environments including heavy metal (HM) stress. However, our knowledge about the roles of DSE in improving HM tolerance of their host plants is poor. In this study, maize (Zea mays L.) was inoculated with a HM tolerant DSE strain Exophiala pisciphila H93 in lead (Pb), zinc (Zn), and cadmium (Cd) contaminated soils. E. pisciphila H93 successfully colonized and formed typical DSE structures in the inoculated maize roots. Colonization of E. pisciphila H93 alleviated the deleterious effects of excessive HM supplements and promoted the growth of maize (roots and shoots) under HM stress conditions, though it significantly decreased the biomass of inoculated maize under no HM stress. Further analysis showed that the colonization of E. pisciphila H93 improved the tolerance of maize to HM by restricting the translocation of HM ions from roots to shoots. This study demonstrated that under higher HM stress, such a mutual symbiosis between E. pisciphila and its host (maize) may be an efficient strategy to survive in the stressful environments. PMID:21195456

  5. Characterization and Comparison of Clavibacter michiganensis subsp. nebraskensis Strains Recovered from Epiphytic and Symptomatic Infections of Maize in Iowa

    PubMed Central

    Robertson, Alison E.

    2015-01-01

    Clavibacter michiganensis subsp. nebraskensis (Cmn), the causal organism of Goss’s wilt and leaf blight of maize, can be detected in the phyllosphere of its host prior to disease development. We compared the morphology and pathogenicity of 37 putative isolates of Cmn recovered from asymptomatic and symptomatic maize leaves. Thirty-three of the isolates produced mucoid orange colonies, irrespective of the source of isolation and all but four of these isolates were pathogenic on maize. The remaining 4 isolates recovered from asymptomatic leaves had large fluidal yellow colonies, and were non-pathogenic on maize. Isolates varied in their aggressiveness on a susceptible hybrid of maize but no significant differences in aggressiveness were detected between epiphytic isolates and those recovered from diseased maize tissues. The genomics of Cmn is poorly understood; therefore as a first step to determining what genes may play a role in virulence, we compared 33 putative virulence gene sequences from 6 pathogenic and a non-pathogenic isolate recovered from the phyllosphere. Sequence polymorphisms were detected in 5 genes, cellulase A, two endoglucanases, xylanase B and a pectate lyase but there was no relationship with pathogenicity. Further research is needed to determine what genes play a role in virulence of Cmn. Our data show however, that the virulence factors in Cmn likely differ from those reported for the closely related subspecies michiganensis and sepedonicus. PMID:26599211

  6. Generation of transgenic maize with enhanced provitamin A content.

    PubMed

    Aluru, Maneesha; Xu, Yang; Guo, Rong; Wang, Zhenguo; Li, Shanshan; White, Wendy; Wang, Kan; Rodermel, Steve

    2008-01-01

    Vitamin A deficiency (VAD) affects over 250 million people worldwide and is one of the most prevalent nutritional deficiencies in developing countries, resulting in significant socio-economic losses. Provitamin A carotenoids such as beta-carotene, are derived from plant foods and are a major source of vitamin A for the majority of the world's population. Several years of intense research has resulted in the production of 'Golden Rice 2' which contains sufficiently high levels of provitamin A carotenoids to combat VAD. In this report, the focus is on the generation of transgenic maize with enhanced provitamin A content in their kernels. Overexpression of the bacterial genes crtB (for phytoene synthase) and crtI (for the four desaturation steps of the carotenoid pathway catalysed by phytoene desaturase and zeta-carotene desaturase in plants), under the control of a 'super gamma-zein promoter' for endosperm-specific expression, resulted in an increase of total carotenoids of up to 34-fold with a preferential accumulation of beta-carotene in the maize endosperm. The levels attained approach those estimated to have a significant impact on the nutritional status of target populations in developing countries. The high beta-carotene trait was found to be reproducible over at least four generations. Gene expression analyses suggest that increased accumulation of beta-carotene is due to an up-regulation of the endogenous lycopene beta-cylase. These experiments set the stage for the design of transgenic approaches to generate provitamin A-rich maize that will help alleviate VAD. PMID:18723758

  7. 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.

  8. Response of larvae of invasive maize pest Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) to carbon/nitrogen ratio and phytosterol content of European maize varieties.

    PubMed

    Moeser, J; Vidal, S

    2004-08-01

    We studied the performance of larvae of Diabrotica virgifera virgifera LeConte (Chrysomelidae, Galerucinae) on 17 different maize, Zea mays L., varieties from six European countries. Food conversion efficiency studies were performed using a newly established method. The growth of D. v. virgifera (western corn rootworm) larvae and the amount of ingested food was measured and the food conversion efficiency was calculated. In addition, we analyzed the carbon/nitrogen ratio and the phytosterol content of the different varieties. Significant differences between the maize varieties with regard to larval weight gain, amount of ingested food, and food conversion efficiency were encountered. The efficiency of D. v. virgifera in converting root biomass into insect biomass was positively related to the amount of nitrogen in the plant tissue. Furthermore the root phytosterol content influenced the larval weight gain and the amount of ingested food. It was possible to group the varieties into suitable and unsuitable cultivars with regard to D. v. virgifera larval performance on the basis of the phytosterol content. Our results provide the first evidence of the high variability among European maize varieties with respect to D. v. virgifera nutrition. The use of less suitable maize varieties is discussed with respect to integrated pest management strategies. PMID:15384346

  9. Effects of Increasing Concentrations of Sodium Sulfite on Deoxynivalenol and Deoxynivalenol Sulfonate Concentrations of Maize Kernels and Maize Meal Preserved at Various Moisture Content

    PubMed Central

    Paulick, Marleen; Rempe, Inga; Kersten, Susanne; Schatzmayr, Dian; Schwartz-Zimmermann, Heidi Elisabeth; Dänicke, Sven

    2015-01-01

    Under moderate climatic conditions, deoxynivalenol (DON) contamination occurs frequently on cereals. Detoxification measures are required to avoid adverse effects on farm animals. In the present study, a wet preservation method with sodium sulfite (Na2SO3) and propionic acid was tested to titrate the optimum Na2SO3-dose for maximum DON reduction of contaminated maize kernels and meal and to examine the interaction between dose and moisture content in dependence on the preservation duration. The DON concentration decreased with increasing amounts of supplemented Na2SO3 and with increasing duration of the preservation period in a bi-exponential fashion. Additionally, the feed structure and moisture content had a significant influence on the decontaminating effect. Variants with 30% moisture content favored higher DON reduction rates compared to 14% moisture, but especially at low moisture contents, DON reduction was more pronounced in maize kernels than in maize meal. In addition to the decrease of DON, a concomitant formation of three different DON sulfonates was observed which differed in their formation pattern over the time course of preservation. The overall results and statistical analysis clarified that Na2SO3 addition of 10 g/kg maize at 30% moisture for eight days was necessary to obtain a complete DON reduction. PMID:25760079

  10. Behavioral responses of the leafhopper, Cicadulina storeyi China, a major vector of maize streak virus, to volatile cues from intact and leafhopper-damaged maize.

    PubMed

    Oluwafemi, Sunday; Bruce, Toby J A; Pickett, John A; Ton, Jurriaan; Birkett, Michael A

    2011-01-01

    The chemical ecology of the leafhopper, Cicadulina storeyi China (Homoptera: Cicadellidae), an important vector of Maize Streak Virus (MSV), was studied with a view to developing novel leafhopper control strategies in sub-Saharan Africa. Choice tests using a Y-tube olfactometer revealed that odors from uninfested maize seedlings (Zea mays cv. Delprim) were significantly more attractive to C. storeyi than odors from C. storeyi-infested seedlings. Headspace samples of volatile organic compounds (VOCs) collected from 10 to 12 day-old uninfested seedlings were more attractive than those collected from infested seedlings. While VOCs collected from uninfested maize seedlings were attractive, VOCs collected from C. storeyi-infested seedlings were significantly repellent. Analysis of the collected VOCs by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) led to the identification of myrcene, linalool, (E)-2-decen-1-ol, and decanal from uninfested seedlings, and (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, benzyl acetate, indole, geranyl acetate, (E)-caryophyllene, α-bergamotene, (E)-β-farnesene, β-sesquiphellandrene, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) from infested seedlings. Of these, methyl salicylate, (E)-caryophyllene, (E)-β-farnesene, and TMTT were identified previously as volatile semiochemicals involved in plant defense against other sucking insect pests. When tested individually for behavioral activity, all compounds were repellent for C. storeyi. Moreover, when these induced VOCs were added to the blend of VOCs from uninfested maize seedlings, a shift from attraction to repellency was observed. Addition of methyl salicylate, (E)-β-farnesene, or TMTT resulted in a choice for the solvent control (i.e., repulsion), whereas addition of (E)-caryophyllene resulted in no reduction in host VOC attractiveness. These results show that VOCs induced in maize have the potential to be exploited

  11. 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

  12. Maize lethal necrosis (MLN), an emerging threat to maize-based food security in sub-Saharan Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Spectra of normal and nutrient-deficient maize leaves

    NASA Technical Reports Server (NTRS)

    Al-Abbas, A. H.; Barr, R.; Hall, J. D.; Crane, F. L.; Baumgardner, M. F.

    1973-01-01

    Reflectance, transmittance and absorptance spectra of normal and six types of nutrient-deficient (N, P, K, S, Mg, and Ca) maize (Zea mays L.) leaves were analyzed at 30 selected wavelengths from 500 to 2600 nm. The analysis of variance showed significant differences in reflectance, transmittance and absorptance in the visible wavelengths among leaf numbers 3, 4, and 5, among the seven treatments, and among the interactions of leaf number and treatments. In the infrared wavelengths only treatments produced significant differences. The chlorophyll content of leaves was reduced in all nutrient-deficient treatments. Percent moisture was increased in S-, Mg-, and N-deficiencies. Polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related. Leaves from the P- and Ca-deficient plants absorbed less energy in the near infrared than the normal plants; S-, Mg-, K-, and N-deficient leaves absorbed more than the normal. Both S- and N-deficient leaves had higher temperatues than normal maize leaves.

  14. Genome-Wide Association Study Identifies Candidate Genes for Starch Content Regulation in Maize Kernels.

    PubMed

    Liu, Na; Xue, Yadong; Guo, Zhanyong; Li, Weihua; Tang, Jihua

    2016-01-01

    Kernel starch content is an important trait in maize (Zea mays L.) as it accounts for 65-75% of the dry kernel weight and positively correlates with seed yield. A number of starch synthesis-related genes have been identified in maize in recent years. However, many loci underlying variation in starch content among maize inbred lines still remain to be identified. The current study is a genome-wide association study that used a set of 263 maize inbred lines. In this panel, the average kernel starch content was 66.99%, ranging from 60.60 to 71.58% over the three study years. These inbred lines were genotyped with the SNP50 BeadChip maize array, which is comprised of 56,110 evenly spaced, random SNPs. Population structure was controlled by a mixed linear model (MLM) as implemented in the software package TASSEL. After the statistical analyses, four SNPs were identified as significantly associated with starch content (P ≤ 0.0001), among which one each are located on chromosomes 1 and 5 and two are on chromosome 2. Furthermore, 77 candidate genes associated with starch synthesis were found within the 100-kb intervals containing these four QTLs, and four highly associated genes were within 20-kb intervals of the associated SNPs. Among the four genes, Glucose-1-phosphate adenylyltransferase (APS1; Gene ID GRMZM2G163437) is known as an important regulator of kernel starch content. The identified SNPs, QTLs, and candidate genes may not only be readily used for germplasm improvement by marker-assisted selection in breeding, but can also elucidate the genetic basis of starch content. Further studies on these identified candidate genes may help determine the molecular mechanisms regulating kernel starch content in maize and other important cereal crops. PMID:27512395

  15. "On-off" thermoresponsive coating agent containing salicylic acid applied to maize seeds for chilling tolerance.

    PubMed

    Guan, Yajing; Li, Zhan; He, Fei; Huang, Yutao; Song, Wenjian; Hu, Jin

    2015-01-01

    Chilling stress is an important constraint for maize seed establishment in the field. In this study, a type of "on-off" thermoresponsive coating agent containing poly (N-isopropylacrylamide-co-butylmethacrylate) (Abbr. P(NIPAm-co-BMA)) hydrogel was developed to improve the chilling tolerance of coated maize seed. The P(NIPAm-co-BMA) hydrogel was synthesized by free-radical polymerization of N-isopropylacrylamide (NIPAm) and butylmethacrylate (BMA). Salicylic acid (SA) was loaded in the hydrogel as the chilling resistance agent. SA-loaded P(NIPAm-co-BMA) was used for seed film-coating of two maize varieties, Huang C (HC, chilling-tolerant) and Mo17 (chilling-sensitive), to investigate the coated seed germination and seedling growth status under chilling stress. The results showed that the hydrogel obtained a phase transition temperature near 12°C with a NIPAM to MBA weight ratio of 1: 0.1988 (w/w). The temperature of 12°C was considered the "on-off" temperature for chilling-resistant agent release; the SA was released from the hydrogel more rapidly at external temperatures below 12°C than above 12°C. In addition, when seedlings of both maize varieties suffered a short chilling stress (5°C), higher concentrations of SA-loaded hydrogel resulted in increased germination energy, germination percentage, germination index, root length, shoot height, dry weight of roots and shoots and protective enzyme activities and a decreased malondialdehyde content in coated maize seeds compared to single SA treatments. The majority of these physiological and biochemical parameters achieved significant levels compared with the control. Therefore, SA-loaded P(NIPAm-co-BMA), a nontoxic thermoresponsive hydrogel, can be used as an effective material for chilling tolerance in film-coated maize seeds. PMID:25807522

  16. O-linked glycosylation in maize-expressed human IgA1.

    PubMed

    Karnoup, Anton S; Turkelson, Virgil; Anderson, W H Kerr

    2005-10-01

    O-Linked glycans vary between eukaryotic cell types and play an important role in determining a glycoprotein's properties, including stability, target recognition, and potentially immunogenicity. We describe O-linked glycan structures of a recombinant human IgA1 (hIgA1) expressed in transgenic maize. Up to six proline/hydroxyproline conversions and variable amounts of arabinosylation (Pro/Hyp + Ara) were found in the hinge region of maize-expressed hIgA1 heavy chain (HC) by using a combination of matrix-assisted laser-desorption ionization mass spectrometry (MALDI MS), chromatography, and amino acid analysis. Approximately 90% of hIgA1 was modified in this way. An average molar ratio of six Ara units per molecule of hIgA1 was revealed. Substantial sequence similarity was identified between the HC hinge region of hIgA1 and regions of maize extensin-family of hydroxyproline-rich glycoproteins (HRGP). We propose that because of this sequence similarity, the HC hinge region of maize-expressed hIgA1 can become a substrate for posttranslational conversion of Pro to Hyp by maize prolyl-hydroxylase(s) with the subsequent arabinosylation of the Hyp residues by Hyp-glycosyltransferase(s) in the Golgi apparatus in maize endosperm tissue. The observation of up to six Pro/Hyp hydroxylations combined with extensive arabinosylation in the hIgA1 HC hinge region is well in agreement with the Pro/Hyp hydroxylation model and the Hyp contiguity hypothesis suggested earlier in literature for plant HRGP. For the first time, the extensin-like Hyp/Pro conversion and O-linked arabinosylation are described for a recombinant therapeutic protein expressed in transgenic plants. Our findings are of significance to the field of plant biotechnology and biopharmaceutical industry-developing transgenic plants as a platform for the production of recombinant therapeutic proteins. PMID:15901675

  17. Genetic mapping shows intraspecific variation and transgressive segregation for caterpillar-induced aphid resistance in maize.

    PubMed

    Tzin, Vered; Lindsay, Penelope L; Christensen, Shawn A; Meihls, Lisa N; Blue, Levi B; Jander, Georg

    2015-11-01

    Plants in nature have inducible defences that sometimes lead to targeted resistance against particular herbivores, but susceptibility to others. The metabolic diversity and genetic resources available for maize (Zea mays) make this a suitable system for a mechanistic study of within-species variation in such plant-mediated interactions between herbivores. Beet armyworms (Spodoptera exigua) and corn leaf aphids (Rhopalosiphum maidis) are two naturally occurring maize herbivores with different feeding habits. Whereas chewing herbivore-induced methylation of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc) to form 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) promotes caterpillar resistance, lower DIMBOA-Glc levels favour aphid reproduction. Thus, caterpillar-induced DIMBOA-Glc methyltransferase activity in maize is predicted to promote aphid growth. To test this hypothesis, the impact of S. exigua feeding on R. maidis progeny production was assessed using seventeen genetically diverse maize inbred lines. Whereas aphid progeny production was increased by prior caterpillar feeding on lines B73, Ki11, Ki3 and Tx303, it decreased on lines Ky21, CML103, Mo18W and W22. Genetic mapping of this trait in a population of B73 × Ky21 recombinant inbred lines identified significant quantitative trait loci on maize chromosomes 1, 7 and 10. There is a transgressive segregation for aphid resistance, with the Ky21 alleles on chromosomes 1 and 7 and the B73 allele on chromosome 10 increasing aphid progeny production. The chromosome 1 QTL coincides with a cluster of three maize genes encoding benzoxazinoid O-methyltransferases that convert DIMBOA-Glc to HDMBOA-Glc. Gene expression studies and benzoxazinoid measurements indicate that S. exigua -induced responses in this pathway differentially affect R. maidis resistance in B73 and Ky21. PMID:26462033

  18. Genome-Wide Association Study Identifies Candidate Genes for Starch Content Regulation in Maize Kernels

    PubMed Central

    Liu, Na; Xue, Yadong; Guo, Zhanyong; Li, Weihua; Tang, Jihua

    2016-01-01

    Kernel starch content is an important trait in maize (Zea mays L.) as it accounts for 65–75% of the dry kernel weight and positively correlates with seed yield. A number of starch synthesis-related genes have been identified in maize in recent years. However, many loci underlying variation in starch content among maize inbred lines still remain to be identified. The current study is a genome-wide association study that used a set of 263 maize inbred lines. In this panel, the average kernel starch content was 66.99%, ranging from 60.60 to 71.58% over the three study years. These inbred lines were genotyped with the SNP50 BeadChip maize array, which is comprised of 56,110 evenly spaced, random SNPs. Population structure was controlled by a mixed linear model (MLM) as implemented in the software package TASSEL. After the statistical analyses, four SNPs were identified as significantly associated with starch content (P ≤ 0.0001), among which one each are located on chromosomes 1 and 5 and two are on chromosome 2. Furthermore, 77 candidate genes associated with starch synthesis were found within the 100-kb intervals containing these four QTLs, and four highly associated genes were within 20-kb intervals of the associated SNPs. Among the four genes, Glucose-1-phosphate adenylyltransferase (APS1; Gene ID GRMZM2G163437) is known as an important regulator of kernel starch content. The identified SNPs, QTLs, and candidate genes may not only be readily used for germplasm improvement by marker-assisted selection in breeding, but can also elucidate the genetic basis of starch content. Further studies on these identified candidate genes may help determine the molecular mechanisms regulating kernel starch content in maize and other important cereal crops. PMID:27512395

  19. Field performance of maize grown from Fusarium verticillioides-inoculated seed.

    PubMed

    Yates, I E; Widstrom, N W; Bacon, C W; Glenn, A; Hinton, D M; Sparks, D; Jaworski, A J

    2005-01-01

    Fusarium verticillioides is an important fungus occupying dual roles in the maize plant. The fungus functions as an endophyte, a fungal/host interaction beneficial to the growth of some plants. At other times, the fungus may function as a mycotoxin producing pathogen. The advantages and/or disadvantages of the endophytic relationship must be established in order to target appropriate sites for controlling diseases and mycotoxins in maize. One possibility could be to ensure seed maize is fungal free prior to planting. Reciprocal inoculations were made with two fungal isolates on seed of two maize genotypes. Yield was measured at harvest by ear and seed characters and vegetative growth at one-month intervals for plant survival, height, weight and stem diameter. Yield and vegetative growth differed among mature plants only once based on seed inoculation status. In 1998, plant weight was reduced and seed weight per ear was increased for the dent maize, GT-MAS: gk, grown from F. verticillioides RRC 374-inoculated seed compared to other seed treatments. Most vegetative characters were reduced at the first collection for Silver Queen plants grown from F. verticillioides-inoculated seed in 1997 and 1999, but not in 1998. However, no significant differences occurred among mature Silver Queen plants during any of the three growing seasons. In conclusion, yield and vegetative growth of mature maize plants grown from F. verticillioides-inoculated seed were equal to or greater than plants grown from non-inoculated seed under south Georgia field conditions during 1997, 1998, and 1999. PMID:15750733

  20. 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

  1. Electrotropism of Maize Roots 1

    PubMed Central

    Ishikawa, Hideo; Evans, Michael L.

    1990-01-01

    We examined the kinetics of electrotropic curvature in solutions of low electrolyte concentration using primary roots of maize (Zea mays L., variety Merit). When submerged in oxygenated solution across which an electric field was applied, the roots curved rapidly and strongly toward the positive electrode (anode). The strength of the electrotropic response increased and the latent period decreased with increasing field strength. At a field strength of 7.5 volts per centimeter the latent period was 6.6 minutes and curvature reached 60 degrees in about 1 hour. For electric fields greater than 10 volts per centimeter the latent period was less than 1 minute. There was no response to electric fields less than 2.8 volts per centimeter. Both electrotropism and growth were inhibited when indoleacetic acid (10 micromolar) was included in the medium. The auxin transport inhibitor pyrenoylbenzoic acid strongly inhibited electrotropism without inhibiting growth. Electrotropism was enhanced by treatments that interfere with gravitropism, e.g. decapping the roots or pretreating them with ethyleneglycol-bis-[β-ethylether]-N,N,N′,N′-tetraacetic acid. Similarly, roots of agravitropic pea (Pisum sativum, variety Ageotropum) seedlings were more responsive to electrotropic stimulation than roots of normal (variety Alaska) seedlings. The data indicate that the early steps of gravitropism and electrotropism occur by independent mechanisms. However, the motor mechanisms of the two responses may have features in common since auxin and auxin transport inhibitors reduced both gravitropism and electrotropism. PMID:11537481

  2. The influence of feeding crimped kernel maize silage on broiler production, nutrient digestibility and meat quality.

    PubMed

    Ranjitkar, S; Karlsson, A H; Petersen, M A; Bredie, W L P; Petersen, J S; Engberg, R M

    2016-02-01

    Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21 to 25 d to investigate the inclusion of CKMS on nutrient digestibility. In both trials, 4 dietary treatments were used: wheat-based feed (WBF), maize-based feed (MBF), maize-based feed supplemented with 15% CKMS (CKMS-15) and maize-based feed supplemented with 30% CKMS (CKMS-30). Compared with MBF, the dry matter (DM) intakes of broilers receiving CKMS-15 and CKMS-30, respectively, were numerically 7.5 and 6.2% higher and feed conversion ratio 6 and 12% poorer (significant for 30% CKMS), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other three diets. Broiler mortality decreased significantly when CKMS was added to the diet. The consumption of drinking water was significantly lower in all maize-based diets as compared to WBF and was lowest in broilers fed with CKMS-30. An improved litter quality in terms of DM content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS. The addition of CKMS to maize-based diets increased juiciness, tenderness and crumbliness of the meat. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize-based diets is considered an advantageous feeding

  3. Competitive Expression of Endogenous Wheat CENH3 May Lead to Suppression of Alien ZmCENH3 in Transgenic Wheat × Maize Hybrids.

    PubMed

    Chen, Wei; Zhu, Qilin; Wang, Haiyan; Xiao, Jin; Xing, Liping; Chen, Peidu; Jin, Weiwei; Wang, Xiu-E

    2015-11-20

    Uniparental chromosome elimination in wheat × maize hybrid embryos is widely used in double haploid production of wheat. Several explanations have been proposed for this phenomenon, one of which is that the lack of cross-species CENH3 incorporation may act as a barrier to interspecies hybridization. However, it is unknown if this mechanism applies universally. To study the role of CENH3 in maize chromosome elimination of wheat × maize hybrid embryos, maize ZmCENH3 and wheat αTaCENH3-B driven by the constitutive CaMV35S promoter were transformed into wheat variety Yangmai 158. Five transgenic lines for ZmCENH3 and six transgenic lines for αTaCENH3-B were identified. RT-PCR analysis showed that the transgene could be transcribed at a low level in all ZmCENH3 transgenic lines, whereas transcription of endogenous wheat CENH3 was significantly up-regulated. Interestingly, the expression levels of both wheat CENH3 and ZmCENH3 in the ZmCENH3 transgenic wheat × maize hybrid embryos were higher than those in the non-transformed Yangmai 158 × maize hybrid embryos. This indicates that the alien ZmCENH3 in wheat may induce competitive expression of endogenous wheat CENH3, leading to suppression of ZmCENH3 over-expression. Eliminations of maize chromosomes in hybrid embryos of ZmCENH3 transgenic wheat × maize and Yangmai 158 × maize were compared by observations on micronuclei presence, by marker analysis using maize SSRs (simple sequence repeats), and by FISH (fluorescence in situ hybridization) using 45S rDNA as a probe. The results indicate that maize chromosome elimination events in the two crosses are not significantly different. Fusion protein ZmCENH3-YFP could not be detected in ZmCENH3 transgenic wheat by either Western blotting or immnunostaining, whereas accumulation and loading of the αTaCENH3-B-GFP fusion protein was normal in αTaCENH3-B transgenic lines. As ZmCENH3-YFP did not accumulate after AM114 treatment, we speculate that low levels of Zm

  4. Of genes and genomes and the origin of maize.

    PubMed

    White, S; Doebley, J

    1998-08-01

    The crop plant maize (corn) is remarkably dissimilar to its recent wild ancestor, teosinte, making it an extremely interesting model for the study of evolution. Investigations into the evolution of maize are currently being performed at the molecular and morphological levels. Three independent lines of research are poised to shed light on the molecular basis of this spectacular transformation: (1) determining the structure and origin of the maize genome; (2) understanding the role of transposable elements in maize evolution; and (3) elucidating the genetic basis for morphological differences between maize and its wild ancestor teosinte. PMID:9724966

  5. Whole season compared to growth-stage resolved temperature trends: implications for US maize yield

    NASA Astrophysics Data System (ADS)

    Butler, E. E.; Mueller, N. D.; Huybers, P. J.

    2014-12-01

    The effect of temperature on maize yield has generally been considered using a single value for the entire growing season. We compare the effect of temperature trends on yield between two distinct models: a single temperature sensitivity for the whole season and a variable sensitivity across four distinct agronomic development stages. The more resolved variable-sensitivity model indicates roughly a factor of two greater influence of temperature on yield than that implied by the single-sensitivity model. The largest discrepancies occur in silking, which is demonstrated to be the most sensitive stage in the variable-sensitivity model. For instance, whereas median yields are observed to be only 53% of typical values during the hottest 1% of silking-stage temperatures, the single-sensitivity model over predicts median yields of 68% whereas the variable-sensitivity model more correctly predicts median yields of 61%. That the variable sensitivity model is also not capable of capturing the full extent of yield losses suggests that further refinement to represent the non-linear response would be useful. Results from the variable sensitivity model also indicate that management decisions regarding planting times, which have generally shifted toward earlier dates, have led to greater yield benefit than that implied by the single-sensitivity model. Together, the variation of both temperature trends and yield variability within growing stages calls for closer attention to how changes in management interact with changes in climate to ultimately affect yields.

  6. Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.

    PubMed

    Clay, Sharon A; Krack, Kaitlynn K; Bruggeman, Stephanie A; Papiernik, Sharon; Schumacher, Thomas E

    2016-08-01

    Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices. PMID:27153402

  7. Inducible Resistance to Maize Streak Virus

    PubMed Central

    Shepherd, Dionne N.; Dugdale, Benjamin; Martin, Darren P.; Varsani, Arvind; Lakay, Francisco M.; Bezuidenhout, Marion E.; Monjane, Adérito L.; Thomson, Jennifer A.; Dale, James; Rybicki, Edward P.

    2014-01-01

    Maize streak virus (MSV), which causes maize streak disease (MSD), is the major viral pathogenic constraint on maize production in Africa. Type member of the Mastrevirus genus in the family Geminiviridae, MSV has a 2.7 kb, single-stranded circular DNA genome encoding a coat protein, movement protein, and the two replication-associated proteins Rep and RepA. While we have previously developed MSV-resistant transgenic maize lines constitutively expressing “dominant negative mutant” versions of the MSV Rep, the only transgenes we could use were those that caused no developmental defects during the regeneration of plants in tissue culture. A better transgene expression system would be an inducible one, where resistance-conferring transgenes are expressed only in MSV-infected cells. However, most known inducible transgene expression systems are hampered by background or “leaky” expression in the absence of the inducer. Here we describe an adaptation of the recently developed INPACT system to express MSV-derived resistance genes in cell culture. Split gene cassette constructs (SGCs) were developed containing three different transgenes in combination with three different promoter sequences. In each SGC, the transgene was split such that it would be translatable only in the presence of an infecting MSV’s replication associated protein. We used a quantitative real-time PCR assay to show that one of these SGCs (pSPLITrepIII-Rb-Ubi) inducibly inhibits MSV replication as efficiently as does a constitutively expressed transgene that has previously proven effective in protecting transgenic maize from MSV. In addition, in our cell-culture based assay pSPLITrepIII-Rb-Ubi inhibited replication of diverse MSV strains, and even, albeit to a lesser extent, of a different mastrevirus species. The application of this new technology to MSV resistance in maize could allow a better, more acceptable product. PMID:25166274

  8. Ecophysiology of Fusarium temperatum isolated from maize in Argentina.

    PubMed

    Fumero, María Verónica; Sulyok, Michael; Chulze, Sofía

    2016-01-01

    The effect of water activity (aw = 0.95, 0.98 and 0.995), temperature (15, 25 and 30°C), incubation time (7, 14, 21 and 28 days), and their interactions on growth and moniliformin (MON), beauvericin (BEA), fusaproliferin (FUS) and fumonisin B1 (FB1) production by two strains of Fusarium temperatum isolated from Argentinean maize were determined in vitro on sterile layers of maize grains. The results showed that there was a wide range of conditions for growth and mycotoxins production by F. temperatum. Both strains were found to grow faster with increasing aw and at 30°C. In relation to mycotoxin production, the two strains produced more FUS than the other mycotoxins regardless of aw or temperature evaluated (maximum = 50,000 μg g(-1)). For FUS, MON and BEA, the maximum levels were observed at 0.98 aw and 30°C (50,000, 5000 and 2000 μg g(-1) respectively). The lowest levels for these three mycotoxins were detected at 15°C and 0.95 aw (1700 and 100 μg g(-1) for FUS and MON respectively), and at 0.98 aw (400 μg g(-1) for BEA). The maximum levels of FB1 were produced at 15°C and 0.98 aw (1000 μg g(-1)). At all aw and temperatures combinations evaluated there was an increase in toxin concentrations with time incubation. The maximum levels were detected at 21 days. Statistical analyses of aw, temperature, incubation time, and the two- and three-way interactions between them showed significant effects on mycotoxins production by F. temperatum. For its versatility on growth and mycotoxin production, F. temperatum represents a toxicological risk for maize in the field and also during grain storage. PMID:26535974

  9. 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. PMID:25802185

  10. 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

  11. 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

  12. Chemical and agronomic development of Kalanchoe brasiliensis Camb. and Kalanchoe pinnata Pers under light and temperature levels.

    PubMed

    Cruz, Bruna P; Chedier, Luciana M; Fabri, Rodrigo L; Pimenta, Daniel S

    2011-12-01

    This study compares the development of Kalanchoe brasiliensis and Kalanchoe pinnata, which are medicinal species known as "saião" and "folha da fortuna" that are used interchangeably by the population for medicinal purposes. The experiment consisted of 20 plots/species planted in plastic bags with homogeneous substrate in a randomized design, which grown under light levels (25%, 50%, 70%, full sunlight) at environment temperature, and a treatment under a plastic with greater temperature range than the external environment. It was obtained for K. pinnata a greater plant height, total length of sprouts, stems, production and dry matter content of leaves than that obtained for K. brasiliensis, which achieved higher averages only for the length of lateral branches. The species showed increases in height, which varied in inverse proportion to the light, and it was observed the influence of temperature in K. pinnata. The production and dry matter content of leaves were proportional to the luminosity; the same occurred in the thickness of leaves for K. brasiliensis. In the swelling index and Brix degree, K. brasiliensis showed higher averages than K. pinnata. In relation to the total content of flavonoids it was not observed significant differences for both species. The analyzed parameters showed the main differences in the agronomic development of the two species. PMID:22146966

  13. Variability, heritability and genetic advance in some agronomic and forage quality characters of spring triticale in western Canada.

    PubMed

    Aljarrah, Mazen; Oatway, Lori; Albers, Susan; Bergen, Colin

    2014-01-01

    The aim of this study was to estimate variability, broad sense heritability, and genetic advance for dry matter yield (DMY), days to anthesis (ANTH), plant height (HT), in-vitro fiber digestibility-30h (IVFD), lignin (LIGN), starch (STAR %), crude protein content (CP %), acid detergent fiber (ADF) and neutral detergent fiber (NDF) in spring triticale genotypes. Eighteen genotypes were tested at the Field Crop Development Centre (FCDC) in Lacombe, Alberta in 2010-2011 and 2011-2012 growing season. The experimental design was randomized complete block design with 3 replicates. Combined analysis of variance was carried out using SAS Enterprise 4.2 statistical package. Heritability was estimated following the variance component method. Simple correlation coefficients were determined among all traits using two years average data. The genotype mean squares were significant (P ≤ 0.05) for DMY, ANTH, HT, IFVD, ADF, NDF, STAR %, LIGN, and CP %. The effect of year was also highly significant on all studied traits. The phenotypic coefficient of variation was higher than the genetic coefficient of variation for all traits, indicating high influence of the environment on these traits. The significant genetic variability and the high heritability combined with high genetic advance of HT, STAR% and ADF in triticale genotypes suggested that selection could be successfully practiced for those traits. Correlation analysis showed significant and positive correlation of DMY with ANTH and HT, indicating that late and tall genotypes are more suitable as a forage type and they tend to produce more biomass yield. However, DMY did not show any significant correlation with the digestibility. IVFD and STAR % were negatively correlated with LIGN. In general, these results indicated that breeding for low lignin and high starch content will improve the digestibility in triticale genotypes. The preliminary results of this study were promising. Further research must include more diverse

  14. Global warming presents new challenges for maize pest management

    NASA Astrophysics Data System (ADS)

    Diffenbaugh, Noah S.; Krupke, Christian H.; White, Michael A.; Alexander, Corinne E.

    2008-10-01

    It has been conjectured that global warming will increase the prevalence of insect pests in many agro-ecosystems. In this paper, we quantitatively assess four of the key pests of maize, one of the most important systems in North American grain production. Using empirically generated estimates of pest overwintering thresholds and degree-day requirements, along with climate change projections from a high-resolution climate model, we project potential future ranges for each of these pests in the United States. Our analysis suggests the possibility of increased winter survival and greater degree-day accumulations for each of the pests surveyed. We find that relaxed cold limitation could expand the range of all four pest taxa, including a substantial range expansion in the case of corn earworm (H. zea), a migratory, cold-intolerant pest. Because the corn earworm is a cosmopolitan pest that has shown resistance to insecticides, our results suggest that this expansion could also threaten other crops, including those in high-value areas of the western United States. Because managing significant additional pressure from this suite of established pests would require additional pest management inputs, the projected decreases in cold limitation and increases in heat accumulation have the potential to significantly alter the pest management landscape for North American maize production. Further, these range expansions could have substantial economic impacts through increased seed and insecticide costs, decreased yields, and the downstream effects of changes in crop yield variability.

  15. Quantitative trait loci for biofortification traits in maize grain.

    PubMed

    Simić, Domagoj; Mladenović Drinić, Snezana; Zdunić, Zvonimir; Jambrović, Antun; Ledencan, Tatjana; Brkić, Josip; Brkić, Andrija; Brkić, Ivan

    2012-01-01

    Detecting genes that influence biofortification traits in cereal grain could help increase the concentrations of bioavailable mineral elements in crops to solve the global mineral malnutrition problem. The aims of this study were to detect the quantitative trait loci (QTLs) for phosphorus (P), iron (Fe), zinc (Zn), and magnesium (Mg) concentrations in maize grain in a mapping population, as well as QTLs for bioavailable Fe, Zn, and Mg, by precalculating their respective ratios with P. Elemental analysis of grain samples was done by coupled plasma-optical emission spectrometry in 294 F(4) lines of a biparental population taken from field trials of over 3 years. The population was mapped using sets of 121 polymorphic markers. QTL analysis revealed 32 significant QTLs detected for 7 traits, of which some were colocalized. The Additive-dominant model revealed highly significant additive effects, suggesting that biofortification traits in maize are generally controlled by numerous small-effect QTLs. Three QTLs for Fe/P, Zn/P, and Mg/P were colocalized on chromosome 3, coinciding with simple sequence repeats marker bnlg1456, which resides in close proximity to previously identified phytase genes (ZM phys1 and phys2). Thus, we recommend the ratios as bioavailability traits in biofortification research. PMID:22071312

  16. [Detection of genetic modification in maize and maize products by ELISA-test].

    PubMed

    Urbanek-Karłowska, Bogumiła; Sawilska-Rautenstrauch, Dorota; Jedra, Małgorzata; Badowski, Paweł

    2003-01-01

    Enzyme immunoassay methods--TRAIT Test--was applied for detection of genetic modification in maize seeds and foodstuffs, which have been produced from this crop. TRAIT Test is based on the identification GMO protein Cry 1Ab produced by a gene derived from Bacillus thuringiensis (Bt) incorporated into insect resistant corn grain. The experiment was carried out on maize standards and foodstuffs from Warsaw market. The positive result was obtained for one maize product, which was not labelled as GMO. The presence of GMO material was approximately equal to 1%. In conclusion, this test is proper for fast routine qualitative (yes/no) determination GMO material in maize seeds and unprocessed food products. PMID:15052732

  17. Sequencing, assembly, and annotation of Maize B104 : A maize transformation resource

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize transformation is complicated. Most lines are not readily cultured and transformed, making the germplasm available for genome engineering extremely limited. Developing a better understanding of the genomic regions responsible for differences in culturability and transformability would be a goo...

  18. 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.

  19. Maize pollen is an important allergen in occupationally exposed workers

    PubMed Central

    2011-01-01

    Background The work- or environmental-related type I sensitization to maize pollen is hardly investigated. We sought to determine the prevalence of sensitization to maize pollen among exposed workers and to identify the eliciting allergens. Methods In July 2010, 8 out of 11 subjects were examined who were repeatedly exposed to maize pollen by pollinating maize during their work in a biological research department. All 8 filled in a questionnaire and underwent skin prick testing (SPT) and immune-specific analyses. Results 5 out of the 8 exposed subjects had repeatedly suffered for at least several weeks from rhinitis, 4 from conjunctivitis, 4 from urticaria, and 2 from shortness of breath upon occupational exposure to maize pollen. All symptomatic workers had specific IgE antibodies against maize pollen (CAP class ≥ 1). Interestingly, 4 of the 5 maize pollen-allergic subjects, but none of the 3 asymptomatic exposed workers had IgE antibodies specific for grass pollen. All but one of the maize pollen-allergic subjects had suffered from allergic grass pollen-related symptoms for 6 to 11 years before job-related exposure to maize pollen. Lung function testing was normal in all cases. In immunoblot analyses, the allergenic components could be identified as Zea m 1 and Zea m 13. The reactivity is mostly caused by cross-reactivity to the homologous allergens in temperate grass pollen. Two sera responded to Zea m 3, but interestingly not to the corresponding timothy allergen indicating maize-specific IgE reactivity. Conclusion The present data suggest that subjects pollinating maize are at high risk of developing an allergy to maize pollen as a so far underestimated source of occupational allergens. For the screening of patients with suspected maize pollen sensitization, the determination of IgE antibodies specific for maize pollen is suitable. PMID:22165847

  20. Genetic Diversity and Molecular Evolution of a Violaxanthin De-epoxidase Gene in Maize

    PubMed Central

    Xu, Jing; Li, Zhigang; Yang, Haorui; Yang, Xiaohong; Chen, Cuixia; Li, Hui

    2016-01-01

    Violaxanthin de-epoxidase (VDE) has a critical role in the carotenoid biosynthesis pathway, which is involved in protecting the photosynthesis apparatus from damage caused by excessive light. Here, a VDE gene in maize, ZmVDE1, was cloned and shown to have functional domains in common with the gramineous VDE protein. Candidate gene association analysis indicated that no polymorphic sites in ZmVDE1 were significant association with any of the examined carotenoid-related traits at P = 0.05 in an association panel containing 155 maize inbred lines. Nucleotide diversity analysis of VDE1 in maize and teosinte indicated that its exon had less genetic variation, consistent with the conserved function of VDE1 in plants. In addition, dramatically reduced nucleotide diversity, fewer haplotypes and a significantly negative parameter deviation for Tajima’s D test of ZmVDE1 in maize and teosinte suggested that a potential selective force had acted across the ZmVDE1 locus. We further identified a 4.2 Mb selective sweep with low recombination surrounding the ZmVDE1 locus that resulted in severely reduced nucleotide diversity on chromosome 2. Collectively, natural selection and the conserved domains of ZmVDE1 might show an important role in the xanthophyll cycle of the carotenoid biosynthesis pathway. PMID:27507987