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Sample records for african cultivated rice

  1. Patterns of sequence divergence and evolution of the S orthologous regions between Asian and African cultivated rice species.

    PubMed

    Guyot, Romain; Garavito, Andrea; Gavory, Frédérick; Samain, Sylvie; Tohme, Joe; Ghesquière, Alain; Lorieux, Mathias

    2011-01-01

    A strong postzygotic reproductive barrier separates the recently diverged Asian and African cultivated rice species, Oryza sativa and O. glaberrima. Recently a model of genetic incompatibilities between three adjacent loci: S(1)A, S(1) and S(1)B (called together the S(1) regions) interacting epistatically, was postulated to cause the allelic elimination of female gametes in interspecific hybrids. Two candidate factors for the S(1) locus (including a putative F-box gene) were proposed, but candidates for S(1)A and S(1)B remained undetermined. Here, to better understand the basis of the evolution of regions involved in reproductive isolation, we studied the genic and structural changes accumulated in the S(1) regions between orthologous sequences. First, we established an 813 kb genomic sequence in O. glaberrima, covering completely the S(1)A, S(1) and the majority of the S(1)B regions, and compared it with the orthologous regions of O. sativa. An overall strong structural conservation was observed, with the exception of three isolated regions of disturbed collinearity: (1) a local invasion of transposable elements around a putative F-box gene within S(1), (2) the multiple duplication and subsequent divergence of the same F-box gene within S(1)A, (3) an interspecific chromosomal inversion in S(1)B, which restricts recombination in our O. sativa×O. glaberrima crosses. Beside these few structural variations, a uniform conservative pattern of coding sequence divergence was found all along the S(1) regions. Hence, the S(1) regions have undergone no drastic variation in their recent divergence and evolution between O. sativa and O. glaberrima, suggesting that a small accumulation of genic changes, following a Bateson-Dobzhansky-Muller (BDM) model, might be involved in the establishment of the sterility barrier. In this context, genetic incompatibilities involving the duplicated F-box genes as putative candidates, and a possible strengthening step involving the

  2. Patterns of Sequence Divergence and Evolution of the S1 Orthologous Regions between Asian and African Cultivated Rice Species

    PubMed Central

    Gavory, Frédérick; Samain, Sylvie; Tohme, Joe; Ghesquière, Alain; Lorieux, Mathias

    2011-01-01

    A strong postzygotic reproductive barrier separates the recently diverged Asian and African cultivated rice species, Oryza sativa and O. glaberrima. Recently a model of genetic incompatibilities between three adjacent loci: S1A, S1 and S1B (called together the S1 regions) interacting epistatically, was postulated to cause the allelic elimination of female gametes in interspecific hybrids. Two candidate factors for the S1 locus (including a putative F-box gene) were proposed, but candidates for S1A and S1B remained undetermined. Here, to better understand the basis of the evolution of regions involved in reproductive isolation, we studied the genic and structural changes accumulated in the S1 regions between orthologous sequences. First, we established an 813 kb genomic sequence in O. glaberrima, covering completely the S1A, S1 and the majority of the S1B regions, and compared it with the orthologous regions of O. sativa. An overall strong structural conservation was observed, with the exception of three isolated regions of disturbed collinearity: (1) a local invasion of transposable elements around a putative F-box gene within S1, (2) the multiple duplication and subsequent divergence of the same F-box gene within S1A, (3) an interspecific chromosomal inversion in S1B, which restricts recombination in our O. sativa×O. glaberrima crosses. Beside these few structural variations, a uniform conservative pattern of coding sequence divergence was found all along the S1 regions. Hence, the S1 regions have undergone no drastic variation in their recent divergence and evolution between O. sativa and O. glaberrima, suggesting that a small accumulation of genic changes, following a Bateson-Dobzhansky-Muller (BDM) model, might be involved in the establishment of the sterility barrier. In this context, genetic incompatibilities involving the duplicated F-box genes as putative candidates, and a possible strengthening step involving the chromosomal inversion might participate to

  3. Exploring African Rice Genetic Diversity for Genetic Stock Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    West African cultivated rice (Oryza glaberrima) and its progenitor species, O. barthii, are a source of genes for crop improvement especially pest resistance (blast, sheath blight, brown spot, bacterial blight, bacterial leaf streak, green leafhopper) and tolerance to abiotic stress (drought, acid s...

  4. Investigations of methane emissions from rice cultivation in Indian context.

    PubMed

    Anand, Shalini; Dahiya, R P; Talyan, Vikash; Vrat, Prem

    2005-05-01

    The increasing demand of the growing population requires enhancement in the production of rice. This has a direct bearing on the global environment since the rice cultivation is one of the major contributors to the methane emissions. As the rice cultivation is intensified with the current practices and technologies, the methane fluxes from paddy fields will substantially rise. Improved high yielding rice varieties together with efficient cultivation techniques will certainly contribute to the curtailment of the methane emission fluxes. In this paper, the system dynamic approach is used for estimating the methane emissions from rice fields in India till the year 2020. Mitigation options studied for curtailing the methane emissions include rice production management, use of low methane emitting varieties of rice, water management and fertilizer amendment. The model is validated quantitatively and sensitivity tests are carried out to examine the robustness of the model. PMID:15788188

  5. Loss of function at RAE2, a previously unidentified EPFL, is required for awnlessness in cultivated Asian rice

    PubMed Central

    Bessho-Uehara, Kanako; Wang, Diane R.; Furuta, Tomoyuki; Minami, Anzu; Nagai, Keisuke; Gamuyao, Rico; Asano, Kenji; Angeles-Shim, Rosalyn B.; Shimizu, Yoshihiro; Ayano, Madoka; Komeda, Norio; Doi, Kazuyuki; Miura, Kotaro; Toda, Yosuke; Kinoshita, Toshinori; Okuda, Satohiro; Higashiyama, Tetsuya; Nomoto, Mika; Tada, Yasuomi; Shinohara, Hidefumi; Matsubayashi, Yoshikatsu; Greenberg, Anthony; Wu, Jianzhong; Yasui, Hideshi; Yoshimura, Atsushi; Mori, Hitoshi; McCouch, Susan R.; Ashikari, Motoyuki

    2016-01-01

    Domestication of crops based on artificial selection has contributed numerous beneficial traits for agriculture. Wild characteristics such as red pericarp and seed shattering were lost in both Asian (Oryza sativa) and African (Oryza glaberrima) cultivated rice species as a result of human selection on common genes. Awnedness, in contrast, is a trait that has been lost in both cultivated species due to selection on different sets of genes. In a previous report, we revealed that at least three loci regulate awn development in rice; however, the molecular mechanism underlying awnlessness remains unknown. Here we isolate and characterize a previously unidentified EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family member named REGULATOR OF AWN ELONGATION 2 (RAE2) and identify one of its requisite processing enzymes, SUBTILISIN-LIKE PROTEASE 1 (SLP1). The RAE2 precursor is specifically cleaved by SLP1 in the rice spikelet, where the mature RAE2 peptide subsequently induces awn elongation. Analysis of RAE2 sequence diversity identified a highly variable GC-rich region harboring multiple independent mutations underlying protein-length variation that disrupt the function of the RAE2 protein and condition the awnless phenotype in Asian rice. Cultivated African rice, on the other hand, retained the functional RAE2 allele despite its awnless phenotype. Our findings illuminate the molecular function of RAE2 in awn development and shed light on the independent domestication histories of Asian and African cultivated rice. PMID:27466405

  6. Loss of function at RAE2, a previously unidentified EPFL, is required for awnlessness in cultivated Asian rice.

    PubMed

    Bessho-Uehara, Kanako; Wang, Diane R; Furuta, Tomoyuki; Minami, Anzu; Nagai, Keisuke; Gamuyao, Rico; Asano, Kenji; Angeles-Shim, Rosalyn B; Shimizu, Yoshihiro; Ayano, Madoka; Komeda, Norio; Doi, Kazuyuki; Miura, Kotaro; Toda, Yosuke; Kinoshita, Toshinori; Okuda, Satohiro; Higashiyama, Tetsuya; Nomoto, Mika; Tada, Yasuomi; Shinohara, Hidefumi; Matsubayashi, Yoshikatsu; Greenberg, Anthony; Wu, Jianzhong; Yasui, Hideshi; Yoshimura, Atsushi; Mori, Hitoshi; McCouch, Susan R; Ashikari, Motoyuki

    2016-08-01

    Domestication of crops based on artificial selection has contributed numerous beneficial traits for agriculture. Wild characteristics such as red pericarp and seed shattering were lost in both Asian (Oryza sativa) and African (Oryza glaberrima) cultivated rice species as a result of human selection on common genes. Awnedness, in contrast, is a trait that has been lost in both cultivated species due to selection on different sets of genes. In a previous report, we revealed that at least three loci regulate awn development in rice; however, the molecular mechanism underlying awnlessness remains unknown. Here we isolate and characterize a previously unidentified EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family member named REGULATOR OF AWN ELONGATION 2 (RAE2) and identify one of its requisite processing enzymes, SUBTILISIN-LIKE PROTEASE 1 (SLP1). The RAE2 precursor is specifically cleaved by SLP1 in the rice spikelet, where the mature RAE2 peptide subsequently induces awn elongation. Analysis of RAE2 sequence diversity identified a highly variable GC-rich region harboring multiple independent mutations underlying protein-length variation that disrupt the function of the RAE2 protein and condition the awnless phenotype in Asian rice. Cultivated African rice, on the other hand, retained the functional RAE2 allele despite its awnless phenotype. Our findings illuminate the molecular function of RAE2 in awn development and shed light on the independent domestication histories of Asian and African cultivated rice. PMID:27466405

  7. Can the co-cultivation of rice and fish help sustain rice production?

    PubMed

    Hu, Liangliang; Zhang, Jian; Ren, Weizheng; Guo, Liang; Cheng, Yongxu; Li, Jiayao; Li, Kexin; Zhu, Zewen; Zhang, Jiaen; Luo, Shiming; Cheng, Lei; Tang, Jianjun; Chen, Xin

    2016-01-01

    Because rice feeds half of the world's population, a secure global food supply depends on sustainable rice production. Here we test whether the co-cultivation of rice and fish into one "rice-fish system" (RFS; fish refers to aquatic animals in this article) could help sustain rice production. We examined intensive and traditional RFSs that have been widely practiced in China. We found that rice yields did not decrease when fish yield was below a threshold value in each intensive RFS. Below the thresholds, moreover, fish yields in intensive RFSs can be substantially higher than those in traditional RFS without reducing rice yield. Relative to rice monoculture, the use of fertilizer-nitrogen and pesticides decreased, and the farmers' net income increased in RFSs. The results suggest that RFSs can help sustain rice production, and suggest that development of co-culture technologies (i.e. proper field configuration for fish and rice) is necessary to achieve the sustainability. PMID:27349875

  8. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Cultivated wild rice crop insurance provisions. 457... rice crop insurance provisions. The Cultivated Wild Rice Crop Insurance Provisions for the 2009 and... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A...

  9. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Cultivated wild rice crop insurance provisions. 457... rice crop insurance provisions. The Cultivated Wild Rice Crop Insurance Provisions for the 2009 and... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A...

  10. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Cultivated wild rice crop insurance provisions. 457... rice crop insurance provisions. The Cultivated Wild Rice Crop Insurance Provisions for the 2009 and... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A...

  11. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Cultivated wild rice crop insurance provisions. 457... rice crop insurance provisions. The Cultivated Wild Rice Crop Insurance Provisions for the 2009 and... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A...

  12. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Cultivated wild rice crop insurance provisions. 457... rice crop insurance provisions. The Cultivated Wild Rice Crop Insurance Provisions for the 2009 and... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A...

  13. Environmental profile of paddy rice cultivation with different straw management.

    PubMed

    Fusi, Alessandra; Bacenetti, Jacopo; González-García, Sara; Vercesi, Annamaria; Bocchi, Stefano; Fiala, Marco

    2014-10-01

    Italy is the most important European country in terms of paddy rice production. North Italian districts such as Vercelli, Pavia, Novara, and Milano are known as some of the world's most advanced rice cultivation sites. In 2013 Italian rice cultivation represented about 50% of all European rice production by area, and paddy fields extended for over 216,000 ha. Cultivation of rice involves different agricultural activities which have environmental impacts mainly due to fossil fuels and agrochemical requirements as well as the methane emission associated with the fermentation of organic material in the flooded rice fields. In order to assess the environmental consequences of rice production in the District of Vercelli, the cultivation practices most frequently carried out were inventoried and evaluated. The general approach of this study was not only to gather the inventory data for rice production and quantify their environmental impacts, but also to identify the key environmental factors where special attention must be paid. Life Cycle Assessment methodology was applied in this study from a cradle-to-farm gate perspective. The environmental profile was analyzed in terms of seven different impact categories: climate change, ozone depletion, human toxicity, terrestrial acidification, freshwater eutrophication, marine eutrophication, and fossil depletion. Regarding straw management, two different scenarios (burial into the soil of the straw versus harvesting) were compared. The analysis showed that the environmental impact was mainly due to field emissions, the fuel consumption needed for the mechanization of field operations, and the drying of the paddy rice. The comparison between the two scenarios highlighted that the collection of the straw improves the environmental performance of rice production except that for freshwater eutrophication. To improve the environmental performance of rice production, solutions to save fossil fuel and reduce the emissions from

  14. Gene flow from weedy rice populations to cultivated rice varies by plant type

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gene transfer from crops to its weedy and/or wild relatives has been the research focal point during the last decade. Little is known about the rate and consequences of gene transfer from wild or weedy relatives to the cultivated crops. Red rice, a weed which infests ~ 40% of rice acreage in the sou...

  15. A map of rice genome variation reveals the origin of cultivated rice.

    PubMed

    Huang, Xuehui; Kurata, Nori; Wei, Xinghua; Wang, Zi-Xuan; Wang, Ahong; Zhao, Qiang; Zhao, Yan; Liu, Kunyan; Lu, Hengyun; Li, Wenjun; Guo, Yunli; Lu, Yiqi; Zhou, Congcong; Fan, Danlin; Weng, Qijun; Zhu, Chuanrang; Huang, Tao; Zhang, Lei; Wang, Yongchun; Feng, Lei; Furuumi, Hiroyasu; Kubo, Takahiko; Miyabayashi, Toshie; Yuan, Xiaoping; Xu, Qun; Dong, Guojun; Zhan, Qilin; Li, Canyang; Fujiyama, Asao; Toyoda, Atsushi; Lu, Tingting; Feng, Qi; Qian, Qian; Li, Jiayang; Han, Bin

    2012-10-25

    Crop domestications are long-term selection experiments that have greatly advanced human civilization. The domestication of cultivated rice (Oryza sativa L.) ranks as one of the most important developments in history. However, its origins and domestication processes are controversial and have long been debated. Here we generate genome sequences from 446 geographically diverse accessions of the wild rice species Oryza rufipogon, the immediate ancestral progenitor of cultivated rice, and from 1,083 cultivated indica and japonica varieties to construct a comprehensive map of rice genome variation. In the search for signatures of selection, we identify 55 selective sweeps that have occurred during domestication. In-depth analyses of the domestication sweeps and genome-wide patterns reveal that Oryza sativa japonica rice was first domesticated from a specific population of O. rufipogon around the middle area of the Pearl River in southern China, and that Oryza sativa indica rice was subsequently developed from crosses between japonica rice and local wild rice as the initial cultivars spread into South East and South Asia. The domestication-associated traits are analysed through high-resolution genetic mapping. This study provides an important resource for rice breeding and an effective genomics approach for crop domestication research. PMID:23034647

  16. Can the co-cultivation of rice and fish help sustain rice production?

    PubMed Central

    Hu, Liangliang; Zhang, Jian; Ren, Weizheng; Guo, Liang; Cheng, Yongxu; Li, Jiayao; Li, Kexin; Zhu, Zewen; Zhang, Jiaen; Luo, Shiming; Cheng, Lei; Tang, Jianjun; Chen, Xin

    2016-01-01

    Because rice feeds half of the world’s population, a secure global food supply depends on sustainable rice production. Here we test whether the co-cultivation of rice and fish into one “rice-fish system” (RFS; fish refers to aquatic animals in this article) could help sustain rice production. We examined intensive and traditional RFSs that have been widely practiced in China. We found that rice yields did not decrease when fish yield was below a threshold value in each intensive RFS. Below the thresholds, moreover, fish yields in intensive RFSs can be substantially higher than those in traditional RFS without reducing rice yield. Relative to rice monoculture, the use of fertilizer-nitrogen and pesticides decreased, and the farmers’ net income increased in RFSs. The results suggest that RFSs can help sustain rice production, and suggest that development of co-culture technologies (i.e. proper field configuration for fish and rice) is necessary to achieve the sustainability. PMID:27349875

  17. Deciphering Community Structure of Methanotrophs Dwelling in Rice Rhizospheres of an Indian Rice Field Using Cultivation and Cultivation-Independent Approaches.

    PubMed

    Pandit, Pranitha S; Rahalkar, Monali C; Dhakephalkar, Prashant K; Ranade, Dilip R; Pore, Soham; Arora, Preeti; Kapse, Neelam

    2016-04-01

    Methanotrophs play a crucial role in filtering out methane from habitats, such as flooded rice fields. India has the largest area under rice cultivation in the world; however, to the best of our knowledge, methanotrophs have not been isolated and characterized from Indian rice fields. A cultivation strategy composing of a modified medium, longer incubation time, and serial dilutions in microtiter plates was used to cultivate methanotrophs from a rice rhizosphere sample from a flooded rice field in Western India. We compared the cultured members with the uncultured community as revealed by three culture-independent methods. A novel type Ia methanotroph (Sn10-6), at the rank of a genus, and a putative novel species of a type II methanotroph (Sn-Cys) were cultivated from the terminal positive dilution (10(-6)). From lower dilution (10(-4)), a strain of Methylomonas spp. was cultivated. All the three culture-independent analyses, i.e., pmoA clone library, terminal restriction fragment length polymorphism (T-RFLP), and metagenomics approach, revealed the dominance of type I methanotrophs. Only metagenomic analysis showed significant presence of type II methanotrophs, albeit in lower proportion (37 %). All the three isolates showed relevance to the methanotrophic community as depicted by uncultured methods; however, the cultivated members might not be the most dominant ones. In conclusion, a combined cultivation and cultivation-independent strategy yielded us a broader picture of the methanotrophic community from rice rhizospheres of a flooded rice field in India. PMID:26547567

  18. Domestication history and geographical adaptation inferred from a SNP map of African rice.

    PubMed

    Meyer, Rachel S; Choi, Jae Young; Sanches, Michelle; Plessis, Anne; Flowers, Jonathan M; Amas, Junrey; Dorph, Katherine; Barretto, Annie; Gross, Briana; Fuller, Dorian Q; Bimpong, Isaac Kofi; Ndjiondjop, Marie-Noelle; Hazzouri, Khaled M; Gregorio, Glenn B; Purugganan, Michael D

    2016-09-01

    African rice (Oryza glaberrima Steud.) is a cereal crop species closely related to Asian rice (Oryza sativa L.) but was independently domesticated in West Africa ∼3,000 years ago. African rice is rarely grown outside sub-Saharan Africa but is of global interest because of its tolerance to abiotic stresses. Here we describe a map of 2.32 million SNPs of African rice from whole-genome resequencing of 93 landraces. Population genomic analysis shows a population bottleneck in this species that began ∼13,000-15,000 years ago with effective population size reaching its minimum value ∼3,500 years ago, suggesting a protracted period of population size reduction likely commencing with predomestication management and/or cultivation. Genome-wide association studies (GWAS) for six salt tolerance traits identify 11 significant loci, 4 of which are within ∼300 kb of genomic regions that possess signatures of positive selection, suggesting adaptive geographical divergence for salt tolerance in this species. PMID:27500524

  19. The genome sequence of African rice (Oryza glaberrima) and evidence for independent domestication.

    PubMed

    Wang, Muhua; Yu, Yeisoo; Haberer, Georg; Marri, Pradeep Reddy; Fan, Chuanzhu; Goicoechea, Jose Luis; Zuccolo, Andrea; Song, Xiang; Kudrna, Dave; Ammiraju, Jetty S S; Cossu, Rosa Maria; Maldonado, Carlos; Chen, Jinfeng; Lee, Seunghee; Sisneros, Nick; de Baynast, Kristi; Golser, Wolfgang; Wissotski, Marina; Kim, Woojin; Sanchez, Paul; Ndjiondjop, Marie-Noelle; Sanni, Kayode; Long, Manyuan; Carney, Judith; Panaud, Olivier; Wicker, Thomas; Machado, Carlos A; Chen, Mingsheng; Mayer, Klaus F X; Rounsley, Steve; Wing, Rod A

    2014-09-01

    The cultivation of rice in Africa dates back more than 3,000 years. Interestingly, African rice is not of the same origin as Asian rice (Oryza sativa L.) but rather is an entirely different species (i.e., Oryza glaberrima Steud.). Here we present a high-quality assembly and annotation of the O. glaberrima genome and detailed analyses of its evolutionary history of domestication and selection. Population genomics analyses of 20 O. glaberrima and 94 Oryza barthii accessions support the hypothesis that O. glaberrima was domesticated in a single region along the Niger river as opposed to noncentric domestication events across Africa. We detected evidence for artificial selection at a genome-wide scale, as well as with a set of O. glaberrima genes orthologous to O. sativa genes that are known to be associated with domestication, thus indicating convergent yet independent selection of a common set of genes during two geographically and culturally distinct domestication processes. PMID:25064006

  20. Effective Suppression of Methane Emission by 2-Bromoethanesulfonate during Rice Cultivation

    PubMed Central

    Waghmode, Tatoba R.; Haque, Md. Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2015-01-01

    2-bromoethanesulfonate (BES) is a structural analogue of coenzyme M (Co-M) and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied. In this pot experiment, different levels of BES (0, 20, 40 and 80 mg kg-1) were applied to study its effect on CH4 emission and plant growth during rice cultivation. Application of BES effectively suppressed CH4 emission when compared with control soil during rice cultivation. The CH4 emission rates were significantly (P<0.001) decreased by BES application possibly due to significant (P<0.001) reduction of methnaogenic biomarkers like Co-M concentration and mcrA gene copy number (i.e. methanogenic abunadance). BES significantly (P<0.001) reduced methanogen activity, while it did not affect soil dehydrogenase activity during rice cultivation. A rice plant growth and yield parameters were not affected by BES application. The maximum CH4 reduction (49% reduction over control) was found at 80 mg kg-1 BES application during rice cultivation. It is, therefore, concluded that BES could be a suitable soil amendment for reducing CH4 emission without affecting rice plant growth and productivity during rice cultivation. PMID:26562416

  1. Effective Suppression of Methane Emission by 2-Bromoethanesulfonate during Rice Cultivation.

    PubMed

    Waghmode, Tatoba R; Haque, Md Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2015-01-01

    2-bromoethanesulfonate (BES) is a structural analogue of coenzyme M (Co-M) and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied. In this pot experiment, different levels of BES (0, 20, 40 and 80 mg kg-1) were applied to study its effect on CH4 emission and plant growth during rice cultivation. Application of BES effectively suppressed CH4 emission when compared with control soil during rice cultivation. The CH4 emission rates were significantly (P<0.001) decreased by BES application possibly due to significant (P<0.001) reduction of methnaogenic biomarkers like Co-M concentration and mcrA gene copy number (i.e. methanogenic abunadance). BES significantly (P<0.001) reduced methanogen activity, while it did not affect soil dehydrogenase activity during rice cultivation. A rice plant growth and yield parameters were not affected by BES application. The maximum CH4 reduction (49% reduction over control) was found at 80 mg kg-1 BES application during rice cultivation. It is, therefore, concluded that BES could be a suitable soil amendment for reducing CH4 emission without affecting rice plant growth and productivity during rice cultivation. PMID:26562416

  2. The archaeobotany of Asian rice expansion and the development of wet-field cultivation

    NASA Astrophysics Data System (ADS)

    Fuller, D.

    2008-12-01

    Archaeobotanical evidence provides direct data on past human diet and agriculture, including a geographical and chronological framework for studying the expansion of rice agriculture. The growth of systematic archaeobotanical sampling in recent years has allowed for the past presence of rice to be seen in relation to cultivation of other crops and associated weeds. The weed flora provides a basis for inferring the nature of cultivation systems, whether rain-fed dry rice or wetland "paddy" rice, a key distinction for considerations of past methane production. Nevertheless, current data is very unevenly distributed. This poster will summarize available evidence for the origins and spread of rice in South Asia (India and Pakistan), and mainland and Island Southeast Asia deriving from an earlier Chinese domestication. Where possible, such as in India or China, the potential of the weed flora remains for distinguishing wetland rice crops will be summarized. In broad terms, although the origins of rice use and cultivation begins by or during the Middle Holocene (6000- 3000 BC), rice cultivation spread outside the regions of the wild progenitor after this time. Two phases of rice expansion can be distinguished. Phase 1, between 3000 and 1500 BC, introduced rice to Southeast Asia, probably under wetland cultivation, and the spread of dry rice over northern India and Pakistan. Phase 2, taking place between 1000 and 0 BC, sees the spread of rice throughout the Southern Indian Peninsula, with weed evidence suggesting irrigated wetland rice. Similarly, this period sees the spread of intensive paddy agriculture through Korea and Japan, but in Southeast Asia is probably related to a spread of rice in upland, dry field systems.

  3. Rice cultivation and methane emission: Documentation of distributed geographic data sets

    NASA Technical Reports Server (NTRS)

    Matthews, Elaine; John, Jasmin; Fung, Inez

    1994-01-01

    High-resolution global data bases on the geographic and seasonal distribution of rice cultivation and associated methane emission, compiled by Matthews et al., were archived for public use. In addition to the primary data sets identifying location, seasonality, and methane emission from rice cultivation, a series of supporting data sets is included, allowing users not only to replicate the work of Matthews et al. but to investigate alternative cultivation and emission scenarios. The suite of databases provided, at 1 latitude by 1 longitude resolution for the globe, includes (1) locations of rice cultivation, (2) monthly arrays of actively growing rice areas, (3) countries and political subdivisions, and (4) monthly arrays of methane emission from rice cultivation. Ancillary data include (1) a listing, by country, of harvested rice areas and seasonal distribution of crop cycles and (2) country names and codes. Summary tables of zonal/monthly distributions of actively growing rice areas and of methane emissions are presented. Users should consult original publications for complete discussion of the data bases. This short paper is designed only to document formats of the distributed information and briefly describe the contents of the data sets and their initial application to evaluating the role of rice cultivation in the methane budget.

  4. Modelling the Geographical Origin of Rice Cultivation in Asia Using the Rice Archaeological Database

    PubMed Central

    Silva, Fabio; Stevens, Chris J.; Weisskopf, Alison; Castillo, Cristina; Qin, Ling; Bevan, Andrew; Fuller, Dorian Q.

    2015-01-01

    We have compiled an extensive database of archaeological evidence for rice across Asia, including 400 sites from mainland East Asia, Southeast Asia and South Asia. This dataset is used to compare several models for the geographical origins of rice cultivation and infer the most likely region(s) for its origins and subsequent outward diffusion. The approach is based on regression modelling wherein goodness of fit is obtained from power law quantile regressions of the archaeologically inferred age versus a least-cost distance from the putative origin(s). The Fast Marching method is used to estimate the least-cost distances based on simple geographical features. The origin region that best fits the archaeobotanical data is also compared to other hypothetical geographical origins derived from the literature, including from genetics, archaeology and historical linguistics. The model that best fits all available archaeological evidence is a dual origin model with two centres for the cultivation and dispersal of rice focused on the Middle Yangtze and the Lower Yangtze valleys. PMID:26327225

  5. Modelling the Geographical Origin of Rice Cultivation in Asia Using the Rice Archaeological Database.

    PubMed

    Silva, Fabio; Stevens, Chris J; Weisskopf, Alison; Castillo, Cristina; Qin, Ling; Bevan, Andrew; Fuller, Dorian Q

    2015-01-01

    We have compiled an extensive database of archaeological evidence for rice across Asia, including 400 sites from mainland East Asia, Southeast Asia and South Asia. This dataset is used to compare several models for the geographical origins of rice cultivation and infer the most likely region(s) for its origins and subsequent outward diffusion. The approach is based on regression modelling wherein goodness of fit is obtained from power law quantile regressions of the archaeologically inferred age versus a least-cost distance from the putative origin(s). The Fast Marching method is used to estimate the least-cost distances based on simple geographical features. The origin region that best fits the archaeobotanical data is also compared to other hypothetical geographical origins derived from the literature, including from genetics, archaeology and historical linguistics. The model that best fits all available archaeological evidence is a dual origin model with two centres for the cultivation and dispersal of rice focused on the Middle Yangtze and the Lower Yangtze valleys. PMID:26327225

  6. Effect of Rice Cultivation Systems on Indigenous Arbuscular Mycorrhizal Fungal Community Structure

    PubMed Central

    Watanarojanaporn, Nantida; Boonkerd, Nantakorn; Tittabutr, Panlada; Longtonglang, Aphakorn; Young, J. Peter W.; Teaumroong, Neung

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) in an agricultural ecosystem are necessary for proper management of beneficial symbiosis. Here we explored how the patterns of the AMF community in rice roots were affected by rice cultivation systems (the system of rice intensification [SRI] and the conventional rice cultivation system [CS]), and by compost application during growth stages. Rice plants harvested from SRI-managed plots exhibited considerably higher total biomass, root dry weight, and seed fill than those obtained from conventionally managed plots. Our findings revealed that all AMF sequences observed from CS plots belonged (only) to the genus Glomus, colonizing in rice roots grown under this type of cultivation, while rice roots sown in SRI showed sequences belonging to both Glomus and Acaulospora. The AMF community was compared between the different cultivation types (CS and SRI) and compost applications by principle component analysis. In all rice growth stages, AMF assemblages of CS management were not separated from those of SRI management. The distribution of AMF community composition based on T-RFLP data showed that the AMF community structure was different among four cultivation systems, and there was a gradual increase of Shannon-Weaver indices of diversity (H′) of the AMF community under SRI during growth stages. The results of this research indicated that rice grown in SRI-managed plots had more diverse AMF communities than those grown in CS plots. PMID:23719585

  7. Effect of rice cultivation systems on indigenous arbuscular mycorrhizal fungal community structure.

    PubMed

    Watanarojanaporn, Nantida; Boonkerd, Nantakorn; Tittabutr, Panlada; Longtonglang, Aphakorn; Young, J Peter W; Teaumroong, Neung

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) in an agricultural ecosystem are necessary for proper management of beneficial symbiosis. Here we explored how the patterns of the AMF community in rice roots were affected by rice cultivation systems (the system of rice intensification [SRI] and the conventional rice cultivation system [CS]), and by compost application during growth stages. Rice plants harvested from SRI-managed plots exhibited considerably higher total biomass, root dry weight, and seed fill than those obtained from conventionally managed plots. Our findings revealed that all AMF sequences observed from CS plots belonged (only) to the genus Glomus, colonizing in rice roots grown under this type of cultivation, while rice roots sown in SRI showed sequences belonging to both Glomus and Acaulospora. The AMF community was compared between the different cultivation types (CS and SRI) and compost applications by principle component analysis. In all rice growth stages, AMF assemblages of CS management were not separated from those of SRI management. The distribution of AMF community composition based on T-RFLP data showed that the AMF community structure was different among four cultivation systems, and there was a gradual increase of Shannon-Weaver indices of diversity (H') of the AMF community under SRI during growth stages. The results of this research indicated that rice grown in SRI-managed plots had more diverse AMF communities than those grown in CS plots. PMID:23719585

  8. Human energy expenditure in lowland rice cultivation in Malaysia.

    PubMed

    Nawi, N M; Yahya, A; Chen, G; Bockari-Gevao, S M; Maraseni, T N

    2012-01-01

    A study was undertaken to evaluate the human energy consumption of various field operations involved in lowland rice cultivation in Malaysia. Based on recorded average heart rates, fertilizing was found to be the most strenuous operation, with an average heart rate of 138 beats min(-1). There were no significant differences in the average heart rates of the subjects among the individual tasks within the first plowing, second plowing, and harvesting operations, with the average heart rates for these three tasks being 116, 106, and 106 beats min(-1), respectively. The corresponding energy expenditures were 3.90, 3.43, and 3.35 kcal min(-1). Loading the seed into the blower tank and broadcasting the seed were the most critical tasks for the seed broadcasting operation, with average heart rates of 124 and 136 beats min(-1), respectively. The highest energy expenditure of 418.38 kcal ha(-1) was observed for seed broadcasting, and the lowest energy expenditure of 127.96 kcal ha(-1) was for second plowing. The total seasonal human energy expenditure for rice cultivation was estimated to be 5810.71 kcal ha(-1), 55.7% of which was spent on pesticide spraying. Although the sample size in this study was relatively small, the results indicated that human energy expenditure per unit area (kcal ha(-1)) was positively linked to the average heart rate of the subjects and negatively linked to the field capacity. Thus, mechanization of certain tasks could decrease worker physical effort and fatigue and increase production. PMID:22458015

  9. The carbon count of 2000 years of rice cultivation.

    PubMed

    Kalbitz, Karsten; Kaiser, Klaus; Fiedler, Sabine; Kölbl, Angelika; Amelung, Wulf; Bräuer, Tino; Cao, Zhihong; Don, Axel; Grootes, Piet; Jahn, Reinhold; Schwark, Lorenz; Vogelsang, Vanessa; Wissing, Livia; Kögel-Knabner, Ingrid

    2013-04-01

    More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in surface and subsurface soil horizons relative to those of soils under nonpaddy management. We assessed changes in total soil organic as well as of inorganic carbon stocks along a 2000-year chronosequence of soils under paddy and adjacent nonpaddy management in the Yangtze delta, China. The initial organic carbon accumulation phase lasts much longer and is more intensive than previously assumed, e.g., by the Intergovernmental Panel on Climate Change (IPCC). Paddy topsoils accumulated 170-178 kg organic carbon ha(-1) a(-1) in the first 300 years; subsoils lost 29-84 kg organic carbon ha(-1) a(-1) during this period of time. Subsoil carbon losses were largest during the first 50 years after land embankment and again large beyond 700 years of cultivation, due to inorganic carbonate weathering and the lack of organic carbon replenishment. Carbon losses in subsoils may therefore offset soil carbon gains or losses in the surface soils. We strongly recommend including subsoils into global carbon accounting schemes, particularly for paddy fields. PMID:23504888

  10. Significance, progress and prospects for research in simplified cultivation technologies for rice in China

    PubMed Central

    HUANG, M.; IBRAHIM, MD.; XIA, B.; ZOU, Y.

    2011-01-01

    SUMMARY Simplified cultivation technologies for rice have become increasingly attractive in recent years in China because of their social, economical and environmental benefits. To date, several simplified cultivation technologies, such as conventional tillage and seedling throwing (CTST), conventional tillage and direct seeding (CTDS), no-tillage and seedling throwing (NTST), no-tillage and direct seeding (NTDS) and no-tillage and transplanting (NTTP), have been developed in China. Most studies have shown that rice grown under each of these simplified cultivation technologies can produce a grain yield equal to or higher than traditional cultivation (conventional tillage and transplanting). Studies that have described the influences of agronomic practices on yield formation of rice under simplified cultivation have demonstrated that optimizing agronomy practices would increase the efficiencies of simplified cultivation systems. Further research is needed to optimize the management strategies for CTST, CTDS and NTST rice which have developed quickly in recent years, to strengthen basic research for those simplified cultivation technologies that are rarely used at present (such as NTTP and NTDS), to select and breed cultivars suitable for simplified cultivation and to compare the practicability and effectiveness of different simplified cultivation technologies in different rice production regions. PMID:22505773

  11. Utilizing wild species to improve cultivated rice for yield, pest resistance, and response to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 158 million hectares of rice are grown in the world providing a staple food for more than half the world’s population. Although there are several species of Oryza, essentially all cultivated rice is derived from O. sativa which can be genomically differentiated into five sub-populations. There ...

  12. Effects of Bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches.

    PubMed

    Liu, Yongbo; Liu, Fang; Wang, Chao; Quan, Zhanjun; Li, Junsheng

    2016-09-15

    The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking. PMID:27219503

  13. Polyphyletic origin of cultivated rice: based on the interspersion pattern of SINEs.

    PubMed

    Cheng, Chaoyang; Motohashi, Reiko; Tsuchimoto, Suguru; Fukuta, Yoshimichi; Ohtsubo, Hisako; Ohtsubo, Eiichi

    2003-01-01

    The wild rice species Oryza rufipogon with wide intraspecific variation is thought to be the progenitor of the cultivated rice species Oryza sativa with two ecotypes, japonica and indica. To determine the origin of cultivated rice, subfamily members of the rice retroposon p-SINE1, which show insertion polymorphism in the O. sativa -O. rufipogon population, were identified and used to "bar code" each of 101 cultivated and wild rice strains based on the presence or absence of the p-SINE1 members at the respective loci. A phylogenetic tree constructed based on the bar codes given to the rice strains showed that O. sativa strains were classified into two groups corresponding to japonica and indica, whereas O. rufipogon strains were in four groups, in which annual O. rufipogon strains formed a single group, differing from the perennial O. rufipogon strains of the other three groups. Japonica strains were closely related to the O. rufipogon perennial strains of one group, and the indica strains were closely related to the O. rufipogon annual strains, indicating that O. sativa has been derived polyphyletically from O. rufipogon. The subfamily members of p-SINE1 constitute a powerful tool for studying the classification and relationship of rice strains, even when one has limited knowledge of morphology, taxonomy, physiology, and biochemistry of rice strains. PMID:12519908

  14. Development of a rule-based algorithm for rice cultivation mapping using Landsat 8 time series

    NASA Astrophysics Data System (ADS)

    Karydas, Christos G.; Toukiloglou, Pericles; Minakou, Chara; Gitas, Ioannis Z.

    2015-06-01

    In the framework of ERMES project (FP7 66983), an algorithm for mapping rice cultivation extents using mediumhigh resolution satellite data was developed. ERMES (An Earth obseRvation Model based RicE information Service) aims to develop a prototype of downstream service for rice yield modelling based on a combination of Earth Observation and in situ data. The algorithm was designed as a set of rules applied on a time series of Landsat 8 images, acquired throughout the rice cultivation season of 2014 from the plain of Thessaloniki, Greece. The rules rely on the use of spectral indices, such as the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Water Index (NDWI), and the Normalized Seasonal Wetness Index (NSWI), extracted from the Landsat 8 dataset. The algorithm is subdivided into two phases: a) a hard classification phase, resulting in a binary map (rice/no-rice), where pixels are judged according to their performance in all the images of the time series, while index thresholds were defined after a trial and error approach; b) a soft classification phase, resulting in a fuzzy map, by assigning scores to the pixels which passed (as `rice') the first phase. Finally, a user-defined threshold of the fuzzy score will discriminate rice from no-rice pixels in the output map. The algorithm was tested in a subset of Thessaloniki plain against a set of selected field data. The results indicated an overall accuracy of the algorithm higher than 97%. The algorithm was also applied in a study are in Spain (Valencia) and a preliminary test indicated a similar performance, i.e. about 98%. Currently, the algorithm is being modified, so as to map rice extents early in the cultivation season (by the end of June), with a view to contribute more substantially to the rice yield prediction service of ERMES. Both algorithm modes (late and early) are planned to be tested in extra Mediterranean study areas, in Greece, Italy, and Spain.

  15. Characterization of functional trait diversity among Indian cultivated and weedy rice populations.

    PubMed

    Rathore, M; Singh, Raghwendra; Kumar, B; Chauhan, B S

    2016-01-01

    Weedy rice, a menace in rice growing areas globally, is biosimilar having attributes similar to cultivated and wild rice, and therefore is difficult to manage. A study was initiated to characterize the functional traits of 76 weedy rice populations and commonly grown rice cultivars from different agro-climatic zones for nine morphological, five physiological, and three phenological parameters in a field experiment under an augmented block design. Comparison between weedy and cultivated rice revealed a difference in duration (days) from panicle emergence to heading as the most variable trait and awn length as the least variable one, as evidenced from their coefficients of variation. The results of principal component analysis revealed the first three principal components to represent 47.3% of the total variation, which indicates an important role of transpiration, conductance, leaf-air temperature difference, days to panicle emergence, days to heading, flag leaf length, SPAD (soil-plant analysis development), grain weight, plant height, and panicle length to the diversity in weedy rice populations. The variations existing in weedy rice population are a major reason for its wider adaptability to varied environmental conditions and also a problem while trying to manage it. PMID:27072282

  16. Characterization of functional trait diversity among Indian cultivated and weedy rice populations

    PubMed Central

    Rathore, M.; Singh, Raghwendra; Kumar, B.; Chauhan, B. S.

    2016-01-01

    Weedy rice, a menace in rice growing areas globally, is biosimilar having attributes similar to cultivated and wild rice, and therefore is difficult to manage. A study was initiated to characterize the functional traits of 76 weedy rice populations and commonly grown rice cultivars from different agro-climatic zones for nine morphological, five physiological, and three phenological parameters in a field experiment under an augmented block design. Comparison between weedy and cultivated rice revealed a difference in duration (days) from panicle emergence to heading as the most variable trait and awn length as the least variable one, as evidenced from their coefficients of variation. The results of principal component analysis revealed the first three principal components to represent 47.3% of the total variation, which indicates an important role of transpiration, conductance, leaf-air temperature difference, days to panicle emergence, days to heading, flag leaf length, SPAD (soil-plant analysis development), grain weight, plant height, and panicle length to the diversity in weedy rice populations. The variations existing in weedy rice population are a major reason for its wider adaptability to varied environmental conditions and also a problem while trying to manage it. PMID:27072282

  17. Differential response of cultivated and weedy (red) rice to recent and projected increases in atmospheric carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbon dioxide (CO2) is a principle resource for plant growth; as such, the ongoing increase in its concentration may differentially affect the growth of cultivated and wild types of the same species. Red rice in the U.S. is a weedy relative of cultivated rice that represents a major production con...

  18. Oryza nivara, a wild relative of cultivated rice, is a source of genes for improving seedling vigor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) wild relatives are a potential source of genetic diversity for cultivated rice improvement. An advanced backcross population was derived from the U.S. temperate japonica rice variety, M-202, a medium grain commercial cultivar grown in California, crossed with O. nivara Sharma...

  19. Oryza rufipogon as a source of yield improvement in cultivated rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oryza rufipogon is a wild relative of the cultivated species, Oryza sativa, and has been found to possess genes associated with yield improvement and resistance to biotic and abiotic stresses. We have been exploring the use of O. rufipogon as a genetic resource for yield improvement in the USA rice ...

  20. Linking Research, Extension and Farmers: The Case of Mangrove Swamp Rice Cultivation in Sierra Leone.

    ERIC Educational Resources Information Center

    Zinnah, Moses Moroe

    1994-01-01

    Interviews with 124 rice farmers in Sierra Leone revealed that farmers and extension staff have minimal participation and input in testing of new cultivation technologies. The top-down research approach has limited contact among researchers, extension staff, and farmers and affected the utility and application of research. (SK)

  1. OsSPL13 controls grain size in cultivated rice.

    PubMed

    Si, Lizhen; Chen, Jiaying; Huang, Xuehui; Gong, Hao; Luo, Jianghong; Hou, Qingqing; Zhou, Taoying; Lu, Tingting; Zhu, Jingjie; Shangguan, Yingying; Chen, Erwang; Gong, Chengxiang; Zhao, Qiang; Jing, Yufeng; Zhao, Yan; Li, Yan; Cui, Lingling; Fan, Danlin; Lu, Yiqi; Weng, Qijun; Wang, Yongchun; Zhan, Qilin; Liu, Kunyan; Wei, Xinghua; An, Kyungsook; An, Gynheung; Han, Bin

    2016-04-01

    Although genetic diversity has a cardinal role in domestication, abundant natural allelic variations across the rice genome that cause agronomically important differences between diverse varieties have not been fully explored. Here we implement an approach integrating genome-wide association testing with functional analysis on grain size in a diverse rice population. We report that a major quantitative trait locus, GLW7, encoding the plant-specific transcription factor OsSPL13, positively regulates cell size in the grain hull, resulting in enhanced rice grain length and yield. We determine that a tandem-repeat sequence in the 5' UTR of OsSPL13 alters its expression by affecting transcription and translation and that high expression of OsSPL13 is associated with large grains in tropical japonica rice. Further analysis indicates that the large-grain allele of GLW7 in tropical japonica rice was introgressed from indica varieties under artificial selection. Our study demonstrates that new genes can be effectively identified on the basis of genome-wide association data. PMID:26950093

  2. Airborne observations of methane emissions from rice cultivation in the Sacramento Valley of California

    NASA Astrophysics Data System (ADS)

    Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Trainer, M.; Andrews, A. E.; Atlas, E. L.; Blake, D. R.; Daube, B. C.; Dlugokencky, E. J.; Fischer, M. L.; Goldstein, A. H.; Guha, A.; Karl, T.; Kofler, J.; Kosciuch, E.; Misztal, P. K.; Perring, A. E.; Pollack, I. B.; Santoni, G. W.; Schwarz, J. P.; Spackman, J. R.; Wofsy, S. C.; Parrish, D. D.

    2012-12-01

    Airborne measurements of methane (CH4) and carbon dioxide (CO2) were taken over the rice growing region of California's Sacramento Valley in the late spring of 2010 and 2011. From these and ancillary measurements, we show that CH4 mixing ratios were higher in the planetary boundary layer above the Sacramento Valley during the rice growing season than they were before it, which we attribute to emissions from rice paddies. We derive daytime emission fluxes of CH4 between 0.6 and 2.0% of the CO2 taken up by photosynthesis on a per carbon, or mole to mole, basis. We also use a mixing model to determine an average CH4/CO2 flux ratio of -0.6% for one day early in the growing season of 2010. We conclude the CH4/CO2 flux ratio estimates from a single rice field in a previous study are representative of rice fields in the Sacramento Valley. If generally true, the California Air Resources Board (CARB) greenhouse gas inventory emission rate of 2.7 × 1010 g CH4/yr is approximately three times lower than the range of probable CH4 emissions (7.8-9.3 × 1010 g CH4/yr) from rice cultivation derived in this study. We attribute this difference to decreased burning of the residual rice crop since 1991, which leads to an increase in CH4 emissions from rice paddies in succeeding years, but which is not accounted for in the CARB inventory.

  3. A systems-wide comparison of red rice (Oryza longistaminata) tissues identifies rhizome specific genes and proteins that are targets for cultivated rice improvement

    PubMed Central

    2014-01-01

    Background The rhizome, the original stem of land plants, enables species to invade new territory and is a critical component of perenniality, especially in grasses. Red rice (Oryza longistaminata) is a perennial wild rice species with many valuable traits that could be used to improve cultivated rice cultivars, including rhizomatousness, disease resistance and drought tolerance. Despite these features, little is known about the molecular mechanisms that contribute to rhizome growth, development and function in this plant. Results We used an integrated approach to compare the transcriptome, proteome and metabolome of the rhizome to other tissues of red rice. 116 Gb of transcriptome sequence was obtained from various tissues and used to identify rhizome-specific and preferentially expressed genes, including transcription factors and hormone metabolism and stress response-related genes. Proteomics and metabolomics approaches identified 41 proteins and more than 100 primary metabolites and plant hormones with rhizome preferential accumulation. Of particular interest was the identification of a large number of gene transcripts from Magnaportha oryzae, the fungus that causes rice blast disease in cultivated rice, even though the red rice plants showed no sign of disease. Conclusions A significant set of genes, proteins and metabolites appear to be specifically or preferentially expressed in the rhizome of O. longistaminata. The presence of M. oryzae gene transcripts at a high level in apparently healthy plants suggests that red rice is resistant to this pathogen, and may be able to provide genes to cultivated rice that will enable resistance to rice blast disease. PMID:24521476

  4. Methane and nitrous oxide emissions from three paddy rice based cultivation systems in Southwest China

    NASA Astrophysics Data System (ADS)

    Jiang, Changsheng; Wang, Yuesi; Zheng, Xunhua; Zhu, Bo; Huang, Yao; Hao, Qingju

    2006-05-01

    To understand methane (CH4) and nitrous oxide (N2O) emissions from permanently flooded rice paddy fields and to develop mitigation options, a field experiment was conducted in situ for two years (from late 2002 to early 2005) in three rice-based cultivation systems, which are a permanently flooded rice field cultivated with a single time and followed by a non-rice season (PF), a rice-wheat rotation system (RW) and a rice-rapeseed rotation system (RR) in a hilly area in Southwest China. The results showed that the total CH4 emissions from PF were 646.3±52.1 and 215.0±45.4 kg CH4 hm-2 during the rice-growing period and non-rice period, respectively. Both values were much lower than many previous reports from similar regions in Southwest China. The CH4 emissions in the rice-growing season were more intensive in PF, as compared to RW and RR. Only 33% of the total annual CH4 emission in PF occurred in the non-rice season, though the duration of this season is two times longer than the rice season. The annual mean N2O flux in PF was 4.5±0.6 kg N2O hm-2 yr-1. The N2O emission in the rice-growing season was also more intensive than in the non-rice season, with only 16% of the total annual emission occurring in the non-rice season. The amounts of N2O emission in PF were ignorable compared to the CH4 emission in terms of the global warming potential (GWP). Changing PF to RW or RR not only eliminated CH4 emissions in the non-rice season, but also substantially reduced the CH4 emission during the following rice-growing period (ca. 58%, P<0.05). However, this change in cultivation system substantially increased N2O emissions, especially in the non-rice season, by a factor of 3.7 to 4.5. On the 100-year horizon, the integrated GWP of total annual CH4 and N2O emissions satisfies PF≫RR≈RW. The GWP of PF is higher than that of RW and RR by a factor of 2.6 and 2.7, respectively. Of the total GWP of CH4 and N2O emissions, CH4 emission contributed to 93%, 65% and 59% in PF, RW

  5. Comparison on cellular mechanisms of iron and cadmium accumulation in rice: prospects for cultivating Fe-rich but Cd-free rice.

    PubMed

    Gao, Lei; Chang, Jiadong; Chen, Ruijie; Li, Hubo; Lu, Hongfei; Tao, Longxing; Xiong, Jie

    2016-12-01

    Iron (Fe) is essential for rice growth and humans consuming as their staple food but is often deficient because of insoluble Fe(III) in soil for rice growth and limited assimilation for human bodies, while cadmium (Cd) is non-essential and toxic for rice growth and humans if accumulating at high levels. Over-accumulated Cd can cause damage to human bodies. Selecting and breeding Fe-rich but Cd-free rice cultivars are ambitious, challenging and meaningful tasks for researchers. Although evidences show that the mechanisms of Fe/Cd uptake and accumulation in rice are common to some extent as a result of similar entry routes within rice, an increasing number of researchers have discovered distinct mechanisms between Fe/Cd uptake and accumulation in rice. This comprehensive review systematically elaborates and compares cellular mechanisms of Fe/Cd uptake and accumulation in rice, respectively. Mechanisms for maintaining Fe homeostasis and Cd detoxicification are also elucidated. Then, effects of different fertilizer management on Fe/Cd accumulation in rice are discussed. Finally, this review enumerates various approaches for reducing grain Cd accumulation and enhancing Fe content in rice. In summary, understanding of discrepant cellular mechanisms of Fe/Cd accumulation in rice provides guidance for cultivating Fe-fortified rice and has paved the way to develop rice that are tolerant to Cd stress, aiming at breeding Fe-rich but Cd-free rice. PMID:27502932

  6. Sequence polymorphisms in wild, weedy, and cultivated rice suggest seed-shattering locus sh4 played a minor role in Asian rice domestication.

    PubMed

    Zhu, Yongqing; Ellstrand, Norman C; Lu, Bao-Rong

    2012-09-01

    The predominant view regarding Asian rice domestication is that the initial origin of nonshattering involved a single gene of large effect, specifically, the sh4 locus via the evolutionary replacement of a dominant allele for shattering with a recessive allele for reduced shattering. Data have accumulated to challenge this hypothesis. Specifically, a few studies have reported occasional seed-shattering plants from populations of the wild progenitor of cultivated rice (Oryza rufipogon complex) being homozygous for the putative "nonshattering" sh4 alleles. We tested the sh4 hypothesis for the domestication of cultivated rice by obtaining genotypes and phenotypes for a diverse set of samples of wild, weedy, and cultivated rice accessions. The cultivars were fixed for the putative "nonshattering" allele and nonshattering phenotype, but wild rice accessions are highly polymorphic for the putative "nonshattering" allele (frequency ∼26%) with shattering phenotype. All weedy rice accessions are the "nonshattering" genotype at the sh4 locus but with shattering phenotype. These data challenge the widely accepted hypothesis that a single nucleotide mutation ("G"/"T") of the sh4 locus is the major driving force for rice domestication. Instead, we hypothesize that unidentified shattering loci are responsible for the initial domestication of cultivated rice through reduced seed shattering. PMID:23139871

  7. Greenhouse Gas Reductions From Rice Cultivation And The California Cap-and-Trade Market

    NASA Astrophysics Data System (ADS)

    Parkhurst, R.; Salas, W.; Nichols, L.

    2014-12-01

    The California Air Resources Board is developing a compliance offset protocol for rice cultivation practices. This protocol contains three different activities that growers can take to reduce the generation of methane associated with rice cultivation - dry seeding, early drainage, and alternate wetting and drying of fields. All of these practices have been developed using the latest science and have been shown to reduce methane generation without impacting yield. Methane is the second largest anthropogenic source of greenhouse gas (GHG) emissions, accounting for 9% of all U.S. GHG emissions from human activities. Methane is also important because it is more than 20 times more potent a GHG than carbon dioxide. The rice cultivation protocol is important because it will be the first crop-based protocol considered as a part of California's cap-and-trade program. This session will discuss the latest developments with the protocol from stakeholders involved in the creation of the protocol. We invite you to hear lessons learnt from this experience in order to apply similar approaches to other regions/countries and crops.

  8. An economic evaluation comparison of solar water pumping system with engine pumping system for rice cultivation

    NASA Astrophysics Data System (ADS)

    Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn

    2015-08-01

    In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.

  9. Community Dynamics of Arbuscular Mycorrhizal Fungi in High-Input and Intensively Irrigated Rice Cultivation Systems

    PubMed Central

    Wang, Yutao; Li, Ting; Li, Yingwei; Björn, Lars Olof; Rosendahl, Søren; Olsson, Pål Axel; Fu, Xuelin

    2015-01-01

    Application of a mycorrhizal inoculum could be one way to increase the yield of rice plants and reduce the application of fertilizer. We therefore studied arbuscular mycorrhizal fungi (AMF) in the roots of wetland rice (Oryza sativa L.) collected at the seedling, tillering, heading, and ripening stages in four paddy wetlands that had been under a high-input and intensively irrigated rice cultivation system for more than 20 years. It was found that AMF colonization was mainly established in the heading and ripening stages. The AMF community structure was characterized in rhizosphere soils and roots from two of the studied paddy wetlands. A fragment covering the partial small subunit (SSU), the whole internal transcribed spacer (ITS), and the partial large subunit (LSU) rRNA operon regions of AMF was amplified, cloned, and sequenced from roots and soils. A total of 639 AMF sequences were obtained, and these were finally assigned to 16 phylotypes based on a phylogenetic analysis, including 12 phylotypes from Glomeraceae, one phylotype from Claroideoglomeraceae, two phylotypes from Paraglomeraceae, and one unidentified phylotype. The AMF phylotype compositions in the soils were similar between the two surveyed sites, but there was a clear discrepancy between the communities obtained from root and soil. The relatively high number of AMF phylotypes at the surveyed sites suggests that the conditions are suitable for some species of AMF and that they may have an important function in conventional rice cultivation systems. The species richness of root-colonizing AMF increased with the growth of rice, and future studies should consider the developmental stages of this crop in the exploration of AMF function in paddy wetlands. PMID:25681190

  10. Agriculture and the promotion of insect pests: rice cultivation in river floodplains and malaria vectors in The Gambia

    PubMed Central

    Jarju, Lamin BS; Fillinger, Ulrike; Green, Clare; Louca, Vasilis; Majambere, Silas; Lindsay, Steven W

    2009-01-01

    Background Anthropogenic modification of natural habitats can create conditions in which pest species associated with humans can thrive. In order to mitigate for these changes, it is necessary to determine which aspects of human management are associated with the promotion of those pests. Anopheles gambiae, the main Africa malaria vector, often breeds in rice fields. Here the impact of the ancient practice of 'swamp rice' cultivation, on the floodplains of the Gambia River, on the production of anopheline mosquitoes was investigated. Methods Routine surveys were carried out along 500 m transects crossing rice fields from the landward edge of the floodplains to the river during the 2006 rainy season. Aquatic invertebrates were sampled using area samplers and emergence traps and fish sampled using nets. Semi-field experiments were used to investigate whether nutrients used for swamp rice cultivation affected mosquito larval abundance. Results At the beginning of the rainy season rice is grown on the landward edge of the floodplain; the first area to flood with fresh water and one rich in cattle dung. Later, rice plants are transplanted close to the river, the last area to dry out on the floodplain. Nearly all larval and adult stages of malaria vectors were collected 0–100 m from the landward edge of the floodplains, where immature rice plants were grown. These paddies contained stagnant freshwater with high quantities of cattle faeces. Semi-field studies demonstrated that cattle faeces nearly doubled the number of anopheline larvae compared with untreated water. Conclusion Swamp rice cultivation creates ideal breeding sites for malaria vectors. However, only those close to the landward edge harboured vectors. These sites were productive since they were large areas of standing freshwater, rich in nutrients, protected from fish, and situated close to human habitation, where egg-laying mosquitoes from the villages had short distances to fly. The traditional practice

  11. Effects of CaMSRB2-Expressing Transgenic Rice Cultivation on Soil Microbial Communities.

    PubMed

    Sohn, Soo-In; Oh, Young-Ju; Kim, Byung-Yong; Cho, Hyun-Suk

    2016-07-28

    Although many studies on the effects of genetically modified (GM) crops on soil microorganisms have been carried out over the past decades, they have provided contradictory information, even for the same GM crop, owing to the diversity of the soil environments in which they were conducted. This inconsistency in results suggests that the effects of GM crops on soil microorganisms should be considered from many aspects. In this study, we investigated the effects of the GM drought-tolerant rice MSRB2-Bar-8, which expresses the CaMSRB2 gene, on soil microorganisms based on the culture-dependent and culture-independent methods. To this end, rhizosphere soils of GM and non-GM (IM) rice were analyzed for soil chemistry, population densities of soil microorganisms, and microbial community structure (using pyrosequencing technology) at three growth stages (seedling, tillering, and maturity). There was no significant difference in the soil chemistry between GM and non-GM rice. The microbial densities of the GM soils were found to be within the range of those of the non-GM rice. In the pyrosequencing analyses, Proteobacteria and Chloroflexi were dominant at the seedling stage, while Chloroflexi showed dominance over Proteobacteria at the maturity stage in both the GM and non-GM soils. An UPGMA dendrogram showed that the soil microbial communities were clustered by growth stage. Taken together, the results from this study suggest that the effects of MSRB2-Bar-8 cultivation on soil microorganisms are not significant. PMID:27090184

  12. How resilient are African woodlands to disturbance from shifting cultivation?

    PubMed

    McNicol, Iain M; Ryan, Casey M; Williams, Mathew

    2015-12-01

    Large parts of sub-Saharan Africa are experiencing rapid changes in land use and land cover, driven largely by the expansion of small-scale shifting cultivation. This practice creates complex mosaic landscapes with active agricultural fields and patches of mature woodland, interspersed with remnant patches in various stages of regrowth. Our objective here was to examine the rate and extent to which carbon stocks in trees and soils recover after cultivation, and detail how this disturbance and regrowth affect patterns in tree species composition and diversity over 40 years of succession in a miombo woodland landscape in southeast Tanzania. We sampled 67 areas, including plots previously cleared for cultivation, active fields, and mature woodlands for reference purposes. Sites were further stratified by soil texture to test for associated effects. Tree carbon stocks accumulated at an average rate of 0.83 ± 0.10 Mg C x ha(-1) x yr(-1), with soil texture having no clear impact on accumulation rates. Bulk soil carbon stocks on both soil types appeared unaffected by both the initial land clearance and the subsequent regrowth, which resulted in no significant changes over time. Tree species diversity in regrowing plots developed rapidly and within -10 years was equivalent to that of mature woodland. Many of the species found in mature woodlands reappeared relatively quickly after abandonment, although species composition is expected to take considerably longer to recover, with at least 60-80 years required for the compositional similarity between regrowing and mature woodlands to reach levels similar to that among nearby mature woodlands. Through impacts on β-diversity, disturbance was also found to increase the total number of tree species present in the landscape, with many of the recorded species only found in regrowing woodlands. Our results are of relevance to carbon sequestration projects by helping to inform the potential future carbon and biodiversity benefits

  13. Diversity of floral regulatory genes of japonica rice cultivated at northern latitudes

    PubMed Central

    2014-01-01

    Background Rice is considered a short day plant. Originally from tropical regions rice has been progressively adapted to temperate climates and long day conditions in part by modulating its sensitivity to day length. Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1) that code for florigens, are known as major regulatory genes of floral transition in rice. Both Hd3a and RFT1 are regulated by Early heading date 1 (Ehd1) and Days to heading on chromosome 2 (DTH2) while Heading date 1 (Hd1) also governs Hd3a expression. To investigate the mechanism of rice adaptation to temperate climates we have analyzed the natural variation of these five genes in a collection of japonica rice representing the genetic diversity of long day cultivated rice. Results We have investigated polymorphisms of Hd3a, RFT1, Ehd1, Hd1 and DTH2 in a collection of 57 japonica varieties. Hd3a and RFT1 were highly conserved, displaying one major allele. Expression analysis suggested that RFT1 rather than Hd3a could be the pivotal gene controlling flowering under long day conditions. While few alleles were found in the Ehd1 promoter and DTH2 coding region, a high degree of variation in Hd1, including non-functional alleles, was observed. Correlation analysis between gene expression levels and flowering periods suggested the occurrence of other factors, additionally to Ehd1, affecting RFT1 regulation in long day adapted cultivars. Conclusions During domestication, rice expansion was accompanied by changes in the regulatory mechanism of flowering. The existence of non-functional Hd1 alleles and the lack of correlation of their presence with flowering times in plants grown under long day conditions, indicate a minor role of this branch in this process and the existence of an alternative regulatory pathway in northern latitudes. Expression analysis data and a high degree of conservation of RFT1 suggested that this gene could be the main factor regulating flowering among japonica cultivars

  14. Effect of industrial by-products containing electron acceptors on mitigating methane emission during rice cultivation.

    PubMed

    Ali, Muhammad Aslam; Lee, Chang Hoon; Kim, Sang Yoon; Kim, Pil Joo

    2009-10-01

    Three industrial by-products (fly ash, phosphogypsum and blast furnace slag), were evaluated for their potential re-use as soil amendments to reduce methane (CH(4)) emission resulting from rice cultivation. In laboratory incubations, CH(4) production rates from anoxic soil slurries were significantly reduced at amendment levels of 0.5%, 1%, 2% and 5% (wt wt(-1)), while observed CO(2) production rates were enhanced. The level of suppression in methane production was the highest for phosphogypsum, followed by blast slag and then fly ash. In the greenhouse experiment, CH(4) emission rates from the rice planted potted soils significantly decreased with the increasing levels (2-20 Mg ha(-1)) of the selected amendments applied, while rice yield simultaneously increased compared to the control treatment. At 10 Mg ha(-1) application level of the amendments, total seasonal CH(4) emissions were reduced by 20%, 27% and 25%, while rice grain yields were increased by 17%, 15% and 23% over the control with fly ash, phosphogypsum, and blast slag amendments, respectively. The suppression of CH(4) production rates as well as total seasonal CH(4) flux could be due to the increased concentrations of active iron, free iron, manganese oxides, and sulfate in the amended soil, which acted as electron acceptors and controlled methanogens' activity by limiting substrates availability. Among the amendments, blast furnace slag and fly ash contributed mainly to improve the soil nutrients balance and increased the soil pH level towards neutral point, but soil acidity was developed with phosphogypsum application. Conclusively, blast slag among the selected amendments would be a suitable soil amendment for reducing CH(4) emissions as well as sustaining rice productivity. PMID:19560334

  15. Effect of industrial by-products containing electron acceptors on mitigating methane emission during rice cultivation

    SciTech Connect

    Ali, Muhammad Aslam; Lee, Chang Hoon; Kim, Sang Yoon; Kim, Pil Joo

    2009-10-15

    Three industrial by-products (fly ash, phosphogypsum and blast furnace slag), were evaluated for their potential re-use as soil amendments to reduce methane (CH{sub 4}) emission resulting from rice cultivation. In laboratory incubations, CH{sub 4} production rates from anoxic soil slurries were significantly reduced at amendment levels of 0.5%, 1%, 2% and 5% (wt wt{sup -1}), while observed CO{sub 2} production rates were enhanced. The level of suppression in methane production was the highest for phosphogypsum, followed by blast slag and then fly ash. In the greenhouse experiment, CH{sub 4} emission rates from the rice planted potted soils significantly decreased with the increasing levels (2-20 Mg ha{sup -1}) of the selected amendments applied, while rice yield simultaneously increased compared to the control treatment. At 10 Mg ha{sup -1} application level of the amendments, total seasonal CH{sub 4} emissions were reduced by 20%, 27% and 25%, while rice grain yields were increased by 17%, 15% and 23% over the control with fly ash, phosphogypsum, and blast slag amendments, respectively. The suppression of CH{sub 4} production rates as well as total seasonal CH{sub 4} flux could be due to the increased concentrations of active iron, free iron, manganese oxides, and sulfate in the amended soil, which acted as electron acceptors and controlled methanogens' activity by limiting substrates availability. Among the amendments, blast furnace slag and fly ash contributed mainly to improve the soil nutrients balance and increased the soil pH level towards neutral point, but soil acidity was developed with phosphogypsum application. Conclusively, blast slag among the selected amendments would be a suitable soil amendment for reducing CH{sub 4} emissions as well as sustaining rice productivity.

  16. Low risk for helminth infection in wastewater-fed rice cultivation in Vietnam.

    PubMed

    Trang, Do Thuy; van der Hoek, Wim; Cam, Phung Dac; Vinh, Khuong Thanh; Hoa, Nguyen Van; Dalsgaard, Anders

    2006-09-01

    This study was done to assess the risk of helminth infection in association with wastewater-fed rice cultivation in an agricultural setting of Nam Dinh city, Vietnam. In a cross sectional survey data were collected for 202 households in a commune where wastewater was used for irrigation and for 201 households in a commune that used river water. Parasitological examination was conducted on single stool samples obtained from 1,088 individuals aged -15 years from the households. The irrigation water used in both communes was enumerated for helminth eggs and thermotolerant coliforms. The prevalence of infection with Ascaris spp., Trichuris spp., and hookworm was 42.2%, 19.9% and 10.5% respectively, with an overall prevalence of infection with any helminth of 53.4%. Surprisingly, the prevalence of infection with Ascaris and Trichuris was lower among people exposed to wastewater (containing 40-200 helminth eggs/l and 10(4) thermotolerant coliforms/100 ml) compared to people exposed to river water that contained lower worm egg and bacterial numbers. Poor sanitation and hygiene practices and not using protective measures were important independent risk factors for helminth infection. For hookworm infection, no significant difference was observed between the wastewater exposed and unexposed groups. Children living in the wastewater use area had a significantly better nutritional status than those in the area using river water. This suggests a generally higher welfare level of the wastewater use area. In conclusion, this study showed no evidence that rice cultivation with wastewater poses a risk for helminth infection. More detailed studies are needed on the reduction of fecal indicators and helminth eggs in peri-urban wastewater-irrigated rice culture systems and on the relative importance of wastewater irrigation compared to other risk factors for human helminth infection such as poor sanitation and poverty. PMID:17036840

  17. Evolutionary dynamics and structure of the rice blast resistance locus Pi-ta in wild, cultivated, and US weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pi-ta gene in rice has been used to control rice blast pathogen, Magnaporthe oryza, in rice growing areas worldwide for decades. To understand the evolutionary process and natural selection of Pi-ta during rice domestication, we first examined sequences of the genomic region of Pi-ta in geograph...

  18. Changes in carbon stability and microbial activity in size fractions of micro-aggregates in a rice soil chronosequence under long term rice cultivation

    NASA Astrophysics Data System (ADS)

    Pan, Genxing; Liu, Yalong; Wang, Ping; Li, Lianqinfg; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Bian, Rongjun; Ding, Yuanjun; Ma, Chong

    2016-04-01

    Recent studies have shown soil carbon sequestration through physical protection of relative labile carbon intra micro-aggregates with formation of large sized macro-aggregates under good management of soil and agricultural systems. While carbon stabilization had been increasingly concerned as ecosystem properties, the mechanisms underspin bioactivity of soil carbon with increased carbon stability has been still poorly understood. In this study, topsoil samples were collected from rice soils derived from salt marsh under different length of rice cultivation up to 700 years from eastern China. Particle size fractions (PSF) of soil aggregates were separated using a low energy dispersion protocol. Carbon fractions in the PSFs were analyzed either with FTIR spectroscopy. Soil microbial community of bacterial, fungal and archaeal were analyzed with molecular fingerprinting using specific gene primers. Soil respiration and carbon gain from amended maize as well as enzyme activities were measured using lab incubation protocols. While the PSFs were dominated by the fine sand (200-20μm) and silt fraction (20-2μm), the mass proportion both of sand (2000-200μm) and clay (<2μm) fraction increased with prolonged rice cultivation, giving rise to an increasing trend of mean weight diameter of soil aggregates (also referred to aggregate stability). Soil organic carbon was found most enriched in coarse sand fraction (40-60g/kg), followed by the clay fraction (20-24.5g/kg), but depleted in the silt fraction (~10g/kg). Phenolic and aromatic carbon as recalcitrant pool were high (33-40% of total SOC) in both coarse sand and clay fractions than in both fine sand and silt fractions (20-29% of total SOC). However, the ratio of LOC/total SOC showed a weak decreasing trend with decreasing size of the aggregate fractions. Total gene content in the size fractions followed a similar trend to that of SOC. Bacterial and archaeal gene abundance was concentrated in both sand and clay fractions

  19. The influence of continuous rice cultivation and different waterlogging periods on morphology, clay mineralogy, Eh, pH and K in paddy soils.

    PubMed

    Bahmanyar, M A

    2007-09-01

    The effect of different rice cultivation periods on the properties of selected soils in alluvial plain were studied in Mazandaran province (north of Iran) in 2004. Soils were sampled form 0, 6, 16, 26 and over 40 years rice cultivation fields. In each treatment three soil profiles and six nearby auger holes were studied. The present study results indicated that continuous rice cultivation have changed soil moisture regime from xeric to aquic, soil color from brown to grayish, surface horizons from mollic to ochric epipedon and soil structure changed from granular or blocky to massive. Therefore, the soil order has changed from Mollisols to Inceptisols. No illuviation and eluviation of clay minerals occurred as a consequence of rice cultivation. X-ray diffraction analysis showed that clay minerals in non-rice cultivated field were illite, vermiculite, montmorillonite, kaolinite and chlorite, but in rice field were illite, montmorillonite, kaolinite and chlorite, respectively. In contrast of montmorillonite, the amount of illite and vermiculite have been decreased by increasing periods of rice cultivation. The pH values of the saturated soil surface in six weeks past plantation have shifted toward neutrality. While Eh value of non-paddy soils were about +90 mv, surface horizons of paddy soils at field conditions had Eh value about +40, -12, -84, -122 mv, respectively. The amounts of organic matter and available Fe, Mn, Zn and Cu were increased whereas available K was decreased in paddy soils. PMID:19090186

  20. Comparison of the abundance and community structure of ammonia oxidizing prokaryotes in rice rhizosphere under three different irrigation cultivation modes.

    PubMed

    Zhang, Jinping; Zhou, Xiaohong; Chen, Lei; Chen, Zhigang; Chu, Jinyu; Li, Yimin

    2016-05-01

    The abundance, diversity and community structure of ammonia oxidizing archaea (AOA) and bacteria (AOB) in rice rhizosphere soils under three different irrigation cultivated modes, named continuous irrigation mode (C), intermittent irrigation mode (I) and semi-arid mode (M), respectively, were investigated using amoA gene as a molecular biomarker. Clone libraries and quantitative polymerase chain reaction results indicated the highest number of archaeal amoA gene copy was detected in M cultivation mode, then in I and C, whereas, their order of amoA gene copy numbers were I > M > C for AOB, and those were obvious higher than in the bulk soil. The ratios of AOA/AOB were greater than 1 for all samples, suggested the predominance of AOA throughout the period of rice growth in the three different irrigation cultivation modes. Diversity index (SChao1 and Shannon H) have an obvious variation in three different irrigation cultivation modes. For AOA, SChao1 was highest in M and lowest in I mode, whereas, Shannon H was highest in M cultivation mode and lowest in C mode. For AOB, mode M exhibited the highest diversity index (SChao1 and Shannon H), while C showed the lowest highest diversity, suggested long-term water input (continuous mode) may decrease diversity of ammonia oxidizers, whereas mode M may be more appropriate for them. In addition, AOA sequences fall within Nitrososphaera, Nitrosopumilus and Nitrosotalea cluster with proportion of 89.38, 8.85 and 1.77 %, respectively. AOB gene sequences belonged to the Nitrosomonas and Nitrosospira genera with proportion of 90.97 and 9.03 %, respectively. In addition, the abundances, diversity and community structure had an obvious temporal variation in three developmental stages of rice, further suggested rice growth obviously affected the ammonia oxidizing prokaryotes in their rhizosphere soil. PMID:27038955

  1. Identification of β-phenylalanine as a non-protein amino acid in cultivated rice, Oryza sativa

    PubMed Central

    Yokoo, Takayuki; Takata, Ryo; Yan, Jian; Matsumoto, Fuka; Teraishi, Masayoshi; Okumoto, Yutaka; Jander, Georg; Mori, Naoki

    2015-01-01

    Non-protein amino acids, often analogs of the standard 20 protein amino acids, have been discovered in many plant species. Recent research with cultivated rice (Oryza sativa) identified (3R)-β-tyrosine, as well as a tyrosine amino mutase that synthesizes (3R)-β-tyrosine from the protein amino acid (2S)-α-tyrosine. Gas chromatography-mass spectrometry (GC-MS) assays and comparison to an authentic standard showed that β-phenylalanine is also a relatively abundant non-protein amino acid in rice leaves and that its biosynthesis occurs independently from that of β-tyrosine. PMID:27066169

  2. Satellite-based investigation of flood-affected rice cultivation areas in Chao Phraya River Delta, Thailand

    NASA Astrophysics Data System (ADS)

    Son, N. T.; Chen, C. F.; Chen, C. R.; Chang, L. Y.

    2013-12-01

    The occurrence of catastrophic floods in Thailand in 2011 caused significant damage to rice agriculture. This study investigated flood-affected rice cultivation areas in the Chao Phraya River Delta (CRD) rice bowl, Thailand using time-series moderate resolution imaging spectroradiometer (MODIS) data. The data were processed for 2008 (normal flood year) and 2011, comprising four main steps: (1) data pre-processing to construct time-series MODIS vegetation indices (VIs), to filter noise from the time-series VIs by the empirical mode decomposition (EMD), and to mask out non-agricultural areas in respect to water-related cropping areas; (2) flood-affected area classification using the unsupervised linear mixture model (ULMM); (3) rice crop classification using the support vector machines (SVM); and (4) accuracy assessment of flood and rice crop mapping results. The comparisons between the flood mapping results and the ground reference data indicated an overall accuracy of 97.9% and Kappa coefficient of 0.62 achieved for 2008, and 95.7% and 0.77 for 2011, respectively. These results were reaffirmed by close agreement (R2 > 0.8) between comparisons of the two datasets at the provincial level. The crop mapping results compared with the ground reference data revealed that the overall accuracies and Kappa coefficients obtained for 2008 were 88.5% and 0.82, and for 2011 were 84.1% and 0.76, respectively. A strong correlation was also found between MODIS-derived rice area and rice area statistics at the provincial level (R2 > 0.7). Rice crop maps overlaid on the flood-affected area maps showed that approximately 16.8% of the rice cultivation area was affected by floods in 2011 compared to 4.9% in 2008. A majority of the flood-expanded area was observed for the double-cropped rice (10.5%), probably due to flood-induced effects to the autumn-summer and rainy season crops. Information achieved from this study could be useful for agricultural planners to mitigate possible impacts

  3. Chromosome Segment Substitution Lines: A Powerful Tool for the Introgression of Valuable Genes from Oryza Wild Species into Cultivated Rice (O. sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild species of rice (genus Oryza) contain many useful genes but a vast majority of these genes remain untapped to date because it is often difficult to transfer these genes into cultivated rice (O. sativa L.). Chromosome segment substitution lines (CSSLs) and backcross inbred lines (BILs) are power...

  4. Structure of clusters and building blocks in amylopectin from African rice accessions.

    PubMed

    Gayin, Joseph; Abdel-Aal, El-Sayed M; Marcone, Massimo; Manful, John; Bertoft, Eric

    2016-09-01

    Enzymatic hydrolysis in combination with gel-permeation and anion-exchange chromatography techniques were employed to characterise the composition of clusters and building blocks of amylopectin from two African rice (Oryza glaberrima) accessions-IRGC 103759 and TOG 12440. The samples were compared with one Asian rice (Oryza sativa) sample (cv WITA 4) and one O. sativa×O. glaberrima cross (NERICA 4). The average DP of clusters from the African rice accessions (ARAs) was marginally larger (DP=83) than in WITA 4 (DP=81). However, regarding average number of chains, clusters from the ARAs represented both the smallest and largest clusters. Overall, the result suggested that the structure of clusters in TOG 12440 was dense with short chains and high degree of branching, whereas the situation was the opposite in NERICA 4. IRGC 103759 and WITA 4 possessed clusters with intermediate characteristics. The commonest type of building blocks in all samples was group 2 (single branched dextrins) representing 40.3-49.4% of the blocks, while groups 3-6 were found in successively lower numbers. The average number of building blocks in the clusters was significantly larger in NERICA 4 (5.8) and WITA 4 (5.7) than in IRGC 103759 and TOG 12440 (5.1 and 5.3, respectively). PMID:27185123

  5. Enhancement of recombinant human serum albumin in transgenic rice cell culture system by cultivation strategy.

    PubMed

    Liu, Yu-Kuo; Li, Yu-Teng; Lu, Ching-Fan; Huang, Li-Fen

    2015-05-25

    Fusion of the sugar-starvation-induced αAmy3 promoter with its signal peptide has enabled secretion of recombinant human serum albumin (rHSA) into the culture medium. To simplify the production process and increase the rHSA yield in rice suspension cells, a one-step strategem without medium change was adopted. The yield of rHSA was increased sixfold by this one-step approach compared with the two-step recombinant protein process, in which a change of the culture medium to sugar-free medium is required. The one-step strategem was applied to check repeated cycle of rHSA production, and the production of rHSA was also higher in each cycle in the one-step, as opposed to the two-step, production process. The use of the one-step process resulted in fewer damaged cells during the cell sugar starvation phase for recombinant protein production. Furthermore, we scaled up the rHSA production in a 2-L airlift and a 2-L stirred tank bioreactor by the one-step approach, and concluded that rHSA can be enriched to 45 mg L(-1) in plant culture commonly used MS medium by the airlift-type bioreactor. Our results suggest that rHSA production can be enriched by this optimized cultivation strategem. PMID:25765580

  6. Aerobic rice genotypes displayed greater adaptation to water-limited cultivation and tolerance to polyethyleneglycol-6000 induced stress.

    PubMed

    Sandhu, Nitika; Jain, Sunita; Battan, K R; Jain, R K

    2012-01-01

    Water scarcity and drought have seriously threatened traditional rice cultivation practices in several parts of the world including India. In the present investigation, experiments were conducted to see if the water-efficient aerobic rice genotypes developed at UAS, Bangalore (MAS25, MAS26 and MAS109) and IRRI, Philippines (MASARB25 and MASARB868), are endowed with drought tolerance or not. A set of these aerobic and five lowland high-yielding (HKR47 and PAU201, Taraori Basmati, Pusa1121 and Pusa1460) indica rice genotypes were evaluated for: (i) yield and yield components under submerged and aerobic conditions in field, (ii) root morphology and biomass under aerobic conditions in pots in the nethouse, (iii) PEG-6000 (0, -1, -2 and -3 bar) induced drought stress at vegetative stage using a hydroponic culture system and (iv) polymorphism for three SSR markers associated with drought resistance traits. Under submerged conditions, the yield of aerobic rice genotypes declined by 13.4-20.1 % whereas under aerobic conditions the yield of lowland indica/Basmati rice varieties declined by 23-27 %. Under water-limited conditions in pots, aerobic rice genotypes had 54-73.8 % greater root length and 18-60 % higher fresh root biomass compared to lowland indica rice varieties. Notably, root length of MASARB25 was 35 % shorter than MAS25 whereas fresh and dry root biomass of MASARB25 was 10 % and 64 % greater than MAS25. The lowland indica were more sensitive to PEG-stress with a score of 5.9-7.6 for Basmati and 6.1-6.7 for non-aromatic indica rice varieties, than the aerobic rice genotypes (score 2.7-3.3). A set of three microsatellite DNA markers (RM212, RM302 and RM3825) located on chromosome 1 which has been shown to be associated with drought resistance was investigated in the present study. Two of these markers (RM212 and RM302) amplified a specific allele in all the aerobic rice genotypes which were absent in lowland indica rice genotypes. PMID:23573038

  7. QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance

    PubMed Central

    Semagn, Kassa; Sow, Mounirou; Nwilene, Francis; Kolade, Olufisayo; Bocco, Roland; Oyetunji, Olumoye; Mitchell-Olds, Thomas; Ndjiondjop, Marie-Noëlle

    2016-01-01

    African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-parental rice populations (ITA306xBW348-1, ITA306xTOG7106 and ITA306xTOS14519), and to conduct meta QTL (mQTL) analysis to explore whether any genomic regions are conserved across different genetic backgrounds. Composite interval mapping (CIM) conducted on the three populations independently uncovered a total of 28 QTLs associated with pest incidence (12) and pest severity (16). The number of QTLs per population associated with AfRGM resistance varied from three in the ITA306xBW348-1 population to eight in the ITA306xTOG7106 population. Each QTL individually explained 1.3 to 34.1% of the phenotypic variance. The major genomic region for AfRGM resistance had a LOD score and R2 of 60.0 and 34.1% respectively, and mapped at 111 cM on chromosome 4 (qAfrGM4) in the ITA306xTOS14519 population. The meta-analysis reduced the number of QTLs from 28 to 17 mQTLs, each explaining 1.3 to 24.5% of phenotypic variance, and narrowed the confidence intervals by 2.2 cM. There was only one minor effect mQTL on chromosome 1 that was common in the TOS14519 and TOG7106 genetic backgrounds; all other mQTLs were background specific. We are currently fine-mapping and validating the major effect genomic region on chromosome 4 (qAfRGM4). This is the first report in mapping the genomic regions associated with the AfRGM resistance, and will be highly useful for rice breeders. PMID:27508500

  8. QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance.

    PubMed

    Yao, Nasser; Lee, Cheng-Ruei; Semagn, Kassa; Sow, Mounirou; Nwilene, Francis; Kolade, Olufisayo; Bocco, Roland; Oyetunji, Olumoye; Mitchell-Olds, Thomas; Ndjiondjop, Marie-Noëlle

    2016-01-01

    African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-parental rice populations (ITA306xBW348-1, ITA306xTOG7106 and ITA306xTOS14519), and to conduct meta QTL (mQTL) analysis to explore whether any genomic regions are conserved across different genetic backgrounds. Composite interval mapping (CIM) conducted on the three populations independently uncovered a total of 28 QTLs associated with pest incidence (12) and pest severity (16). The number of QTLs per population associated with AfRGM resistance varied from three in the ITA306xBW348-1 population to eight in the ITA306xTOG7106 population. Each QTL individually explained 1.3 to 34.1% of the phenotypic variance. The major genomic region for AfRGM resistance had a LOD score and R2 of 60.0 and 34.1% respectively, and mapped at 111 cM on chromosome 4 (qAfrGM4) in the ITA306xTOS14519 population. The meta-analysis reduced the number of QTLs from 28 to 17 mQTLs, each explaining 1.3 to 24.5% of phenotypic variance, and narrowed the confidence intervals by 2.2 cM. There was only one minor effect mQTL on chromosome 1 that was common in the TOS14519 and TOG7106 genetic backgrounds; all other mQTLs were background specific. We are currently fine-mapping and validating the major effect genomic region on chromosome 4 (qAfRGM4). This is the first report in mapping the genomic regions associated with the AfRGM resistance, and will be highly useful for rice breeders. PMID:27508500

  9. QTL mapping and introgression of yield-related traits from Oryza glumaepatula to cultivated rice ( Oryza sativa) using microsatellite markers.

    PubMed

    Brondani, C.; Rangel, N.; Brondani, V.; Ferreira, E.

    2002-05-01

    Rice ( Oryza sativa) cultivar development currently faces the task of overcoming yield plateaus, which is difficult due to the narrow genetic base of breeding programs. Oryza glumaepatula is a diploid wild relative of cultivated rice, native to Central and South America, and is therefore a potential source of alleles of agronomic importance to rice breeding programs. We studied 11 agronomic traits in BC(2)F(2) families of the interspecific cross Oryza sativa x O. glumaepatula. Transgressive lines which are almost isogenic to the elite recurrent O. sativa parent were identified for most of these traits. Quantitative trait locus (QTL) analysis was performed by single-point and interval mapping using a molecular map based on 157 microsatellite and STS markers. Marker regions accounting for 14.5 to 72.9% of a phenotypic variation trait were identified in 9 of the 12 rice chromosomes. Positive QTL effects from O. glumaepatula were observed in chromosomal regions associated with tillering and panicle-number traits. PMID:12582630

  10. Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance

    PubMed Central

    Pereira, Andy; Tseng, Te-Ming; Zimmer, Paulo Dejalma; Burgos, Nilda Roma

    2015-01-01

    Rice (Oryza sativa L.) cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1) classify the subspecies (ssp.) grouping (japonica or indica) of 21 accessions; 2) evaluate their sensitivity to cold stress; and 3) analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and cultivated

  11. Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance.

    PubMed

    Bevilacqua, Caroline Borges; Basu, Supratim; Pereira, Andy; Tseng, Te-Ming; Zimmer, Paulo Dejalma; Burgos, Nilda Roma

    2015-01-01

    Rice (Oryza sativa L.) cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1) classify the subspecies (ssp.) grouping (japonica or indica) of 21 accessions; 2) evaluate their sensitivity to cold stress; and 3) analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and cultivated

  12. Suitability assessment and mapping of Oyo State, Nigeria, for rice cultivation using GIS

    NASA Astrophysics Data System (ADS)

    Ayoade, Modupe Alake

    2016-07-01

    Rice is one of the most preferred food crops in Nigeria. However, local rice production has declined with the oil boom of the 1970s causing demand to outstrip supply. Rice production can be increased through the integration of Geographic Information Systems (GIS) and crop-land suitability analysis and mapping. Based on the key predictor variables that determine rice yield mentioned in relevant literature, data on rainfall, temperature, relative humidity, slope, and soil of Oyo state were obtained. To develop rice suitability maps for the state, two MCE-GIS techniques, namely the Overlay approach and weighted linear combination (WLC), using fuzzy AHP were used and compared. A Boolean land use map derived from a landsat imagery was used in masking out areas currently unavailable for rice production. Both suitability maps were classified into four categories of very suitable, suitable, moderate, and fairly moderate. Although the maps differ slightly, the overlay and WLC (AHP) approach found most parts of Oyo state (51.79 and 82.9 % respectively) to be moderately suitable for rice production. However, in areas like Eruwa, Oyo, and Shaki, rainfall amount received needs to be supplemented by irrigation for increased rice yield.

  13. Experimentation on cultivation of rice irrigated with a center pivot system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is the staple food for one half of the world’s population, consumed mainly by humans rather than fed to livestock. Rice is an efficient food for supplying carbohydrates, vitamins, and nutrients in diets. Demographers predict the Earth’s population will increase to nine billion people by 2045 an...

  14. Formation of Guaiacol by Spoilage Bacteria from Vanillic Acid, a Product of Rice Koji Cultivation, in Japanese Sake Brewing.

    PubMed

    Ito, Toshihiko; Konno, Mahito; Shimura, Yoichiro; Watanabe, Seiei; Takahashi, Hitoshi; Hashizume, Katsumi

    2016-06-01

    The formation of guaiacol, a potent phenolic off-odor compound in the Japanese sake brewing process, was investigated. Eight rice koji samples were analyzed, and one contained guaiacol and 4-vinylguaiacol (4-VG) at extraordinarily high levels: 374 and 2433 μg/kg dry mass koji, respectively. All samples contained ferulic and vanillic acids at concentrations of mg/kg dry mass koji. Guaiacol forming microorganisms were isolated from four rice koji samples. They were identified as Bacillus subtilis, B. amyloliquefaciens/subtilis, and Staphylococcus gallinarum using 16S rRNA gene sequence. These spoilage bacteria convert vanillic acid to guaiacol and ferulic acid to 4-VG. However, they convert very little ferulic acid or 4-VG to guaiacol. Nine strains of koji fungi tested produced vanillic acid at the mg/kg dry mass koji level after cultivation. These results indicated that spoilage bacteria form guaiacol from vanillic acid, which is a product of koji cultivation in the sake brewing process. PMID:27181257

  15. Eliminating aluminum toxicity in an acid sulfate soil for rice cultivation using plant growth promoting bacteria.

    PubMed

    Panhwar, Qurban Ali; Naher, Umme Aminun; Radziah, Othman; Shamshuddin, Jusop; Razi, Ismail Mohd

    2015-01-01

    Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB), ground magnesium limestone (GML) and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0) at various Al concentrations (0, 50 and 100 μM). Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB), GML and basalt were applied (4 t·ha-1 each). Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase. PMID:25710843

  16. Population Genetic Structure of Cochliobolus miyabeanus on Cultivated Wild Rice (Zizania palustris L.) in Minnesota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cochliobolus miyabeanus (Bipolaris oryzae) is the causal agent of fungal brown spot (FBS) in wild rice (Zizania palustris L.), an aquatic grass, endemic in Minnesota, Wisconsin, and parts of Canada. Grain yield losses can reach up to 74% when the disease starts at the boot stage and continues until ...

  17. Haplotype diversity at the Pi-ta locus in cultivated rice and its wild relataives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pi-ta gene in rice confers resistance to the fungus Magnaporthe oryzae containing AVR-Pita. Pi-ta is predicted to encode a cytoplasmic receptor protein with nucleotide binding sites and leucine rich domain. A panel of 51 oryza accessions consisting of the AA genome species, O. sativa, O. glabe...

  18. Exploring the use of Oryza species to enhance the lipid fraction of cultivated rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past few several years, efforts to collect rice germplasm were broadened to collect more widely from the Oryza genepool. The Oryza genus includes only 23 species, but it is remarkably diverse in-terms of its ecological adaptation. This diversity may not only be restricted to ecological charac...

  19. Pollen and Phytolith Evidence for Rice Cultivation and Vegetation Change during the Mid-Late Holocene at the Jiangli Site, Suzhou, East China

    PubMed Central

    Qiu, Zhenwei; Jiang, Hongen; Ding, Jinlong; Hu, Yaowu; Shang, Xue

    2014-01-01

    Pollen and phytolith analyses were undertaken at the Jiangli site in Suzhou, Jiangsu Province, combined with studies on macrofossils by flotation. The concentration of pollen decreased while the percentage of Poaceae pollen in the profile increased from the late phase of the Majiabang Culture to the Songze Culture suggesting that human impact on the local environment intensified gradually. The discovery of rice paddy implies a relatively advanced rice cultivation in this area during the middle-late Holocene. Other than phytoliths, the high percentage of Oryza-type Poaceae pollen (larger than 40 µm) supplied robust evidence for the existence of rice paddy. Moreover, the fact that the farther from the rice paddy, the lower the concentration and percentage of Poaceae pollen also proves that the dispersal and deposition of pollen is inversely proportional to the distance. PMID:24466254

  20. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-10-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

  1. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    PubMed Central

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-01-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

  2. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence.

    PubMed

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-01-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

  3. New cultive medium for bioconversion of C5 fraction from sugarcane bagasse using rice bran extract

    PubMed Central

    da Silva, Debora Danielle Virginio; Cândido, Elisangela de Jesus; de Arruda, Priscila Vaz; da Silva, Silvio Silvério; Felipe, Maria das Graças de Almeida

    2014-01-01

    The use of hemicellulosic hydrolysates in bioprocesses requires supplementation as to ensure the best fermentative performance of microorganisms. However, in light of conflicting data in the literature, it is necessary to establish an inexpensive and applicable medium for the development of bioprocesses. This paper evaluates the fermentative performance of Scheffersomyces (Pichia) stipitis and Candida guilliermondii growth in sugarcane bagasse hemicellulosic hydrolysate supplemented with different nitrogen sources including rice bran extract, an important by-product of agroindustry and source of vitamins and amino acids. Experiments were carried out with hydrolysate supplemented with rice bran extract and (NH4)2SO4; peptone and yeast extract; (NH4)2SO4, peptone and yeast extract and non-supplemented hydrolysate as a control. S. stipitis produced only ethanol, while C. guilliermondii produced xylitol as the main product and ethanol as by-product. Maximum ethanol production by S. stipitis was observed when sugarcane bagasse hemicellulosic hydrolysate was supplemented with (NH4)2SO4, peptone and yeast extract. Differently, the maximum xylitol formation by C. guilliermondii was obtained by employing hydrolysate supplemented with (NH4)2SO4 and rice bran extract. Together, these findings indicate that: a) for both yeasts (NH4)2SO4 was required as an inorganic nitrogen source to supplement sugarcane bagasse hydrolysate; b) for S. stipitis, sugarcane hemicellulosic hydrolysate must be supplemented with peptone and yeast extract as organic nitrogen source; and: c) for C. guilliermondii, it must be supplemented with rice bran extract. The present study designed a fermentation medium employing hemicellulosic hydrolysate and provides a basis for studies about value-added products as ethanol and xylitol from lignocellulosic materials. PMID:25763056

  4. Genome-Wide Analysis of Polycistronic MicroRNAs in Cultivated and Wild Rice.

    PubMed

    Baldrich, Patricia; Hsing, Yue-Ie Caroline; San Segundo, Blanca

    2016-01-01

    MicroRNAs (miRNAs) are small noncoding RNAs that direct posttranscriptional gene silencing in eukaryotes. They are frequently clustered in the genomes of animals and can be independently transcribed or simultaneously transcribed into single polycistronic transcripts. Only a few miRNA clusters have been described in plants, and most of them are generated from independent transcriptional units. Here, we used a combination of bioinformatic tools and experimental analyses to discover new polycistronic miRNAs in rice. A genome-wide analysis of clustering patterns of MIRNA loci in the rice genome was carried out using a criterion of 3 kb as the maximal distance between two miRNAs. This analysis revealed 28 loci with the ability to form the typical hairpin structure of miRNA precursors in which 2 or more mature miRNAs mapped along the same structure. RT-PCR provided evidence for the polycistronic nature of seven miRNA precursors containing homologous or nonhomologous miRNA species. Polycistronic miRNAs and candidate polycistronic miRNAs are located across different rice chromosomes, except chromosome 12, and resided in both duplicated and nonduplicated chromosomal regions. Finally, most polycistronic and candidate polycistronic miRNAs showed a pattern of conservation in the genome of rice species with an AA genome. The diversity in the organization of MIR genes that are transcribed as polycistrons suggests a versatile mechanism for the control of gene expression in different biological processes and supports additional levels of complexity in miRNA functioning in plants. PMID:27190137

  5. Genome-Wide Analysis of Polycistronic MicroRNAs in Cultivated and Wild Rice

    PubMed Central

    Baldrich, Patricia; Hsing, Yue-Ie Caroline; San Segundo, Blanca

    2016-01-01

    MicroRNAs (miRNAs) are small noncoding RNAs that direct posttranscriptional gene silencing in eukaryotes. They are frequently clustered in the genomes of animals and can be independently transcribed or simultaneously transcribed into single polycistronic transcripts. Only a few miRNA clusters have been described in plants, and most of them are generated from independent transcriptional units. Here, we used a combination of bioinformatic tools and experimental analyses to discover new polycistronic miRNAs in rice. A genome-wide analysis of clustering patterns of MIRNA loci in the rice genome was carried out using a criterion of 3 kb as the maximal distance between two miRNAs. This analysis revealed 28 loci with the ability to form the typical hairpin structure of miRNA precursors in which 2 or more mature miRNAs mapped along the same structure. RT-PCR provided evidence for the polycistronic nature of seven miRNA precursors containing homologous or nonhomologous miRNA species. Polycistronic miRNAs and candidate polycistronic miRNAs are located across different rice chromosomes, except chromosome 12, and resided in both duplicated and nonduplicated chromosomal regions. Finally, most polycistronic and candidate polycistronic miRNAs showed a pattern of conservation in the genome of rice species with an AA genome. The diversity in the organization of MIR genes that are transcribed as polycistrons suggests a versatile mechanism for the control of gene expression in different biological processes and supports additional levels of complexity in miRNA functioning in plants. PMID:27190137

  6. Rice Root Architectural Plasticity Traits and Genetic Regions for Adaptability to Variable Cultivation and Stress Conditions.

    PubMed

    Sandhu, Nitika; Raman, K Anitha; Torres, Rolando O; Audebert, Alain; Dardou, Audrey; Kumar, Arvind; Henry, Amelia

    2016-08-01

    Future rice (Oryza sativa) crops will likely experience a range of growth conditions, and root architectural plasticity will be an important characteristic to confer adaptability across variable environments. In this study, the relationship between root architectural plasticity and adaptability (i.e. yield stability) was evaluated in two traditional × improved rice populations (Aus 276 × MTU1010 and Kali Aus × MTU1010). Forty contrasting genotypes were grown in direct-seeded upland and transplanted lowland conditions with drought and drought + rewatered stress treatments in lysimeter and field studies and a low-phosphorus stress treatment in a Rhizoscope study. Relationships among root architectural plasticity for root dry weight, root length density, and percentage lateral roots with yield stability were identified. Selected genotypes that showed high yield stability also showed a high degree of root plasticity in response to both drought and low phosphorus. The two populations varied in the soil depth effect on root architectural plasticity traits, none of which resulted in reduced grain yield. Root architectural plasticity traits were related to 13 (Aus 276 population) and 21 (Kali Aus population) genetic loci, which were contributed by both the traditional donor parents and MTU1010. Three genomic loci were identified as hot spots with multiple root architectural plasticity traits in both populations, and one locus for both root architectural plasticity and grain yield was detected. These results suggest an important role of root architectural plasticity across future rice crop conditions and provide a starting point for marker-assisted selection for plasticity. PMID:27342311

  7. A Genetic Model for the Female Sterility Barrier Between Asian and African Cultivated Rice Species

    PubMed Central

    Garavito, Andrea; Guyot, Romain; Lozano, Jaime; Gavory, Frédérick; Samain, Sylvie; Panaud, Olivier; Tohme, Joe; Ghesquière, Alain; Lorieux, Mathias

    2010-01-01

    S1 is the most important locus acting as a reproductive barrier between Oryza sativa and O. glaberrima. It is a complex locus, with factors that may affect male and female fertility separately. Recently, the component causing the allelic elimination of pollen was fine mapped. However, the position and nature of the component causing female sterility remains unknown. To fine map the factor of the S1 locus affecting female fertility, we developed a mapping approach based on the evaluation of the degree of female transmission ratio distortion (fTRD) of markers. Through implementing this methodology in four O. sativa × O. glaberrima crosses, the female component of the S1 locus was mapped into a 27.8-kb (O. sativa) and 50.3-kb (O. glaberrima) region included within the interval bearing the male component of the locus. Moreover, evidence of additional factors interacting with S1 was also found. In light of the available data, a model where incompatibilities in epistatic interactions between S1 and the additional factors are the cause of the female sterility barrier between O. sativa and O. glaberrima was developed to explain the female sterility and the TRD mediated by S1. According to our model, the recombination ratio and allelic combinations between these factors would determine the final allelic frequencies observed for a given cross. PMID:20457876

  8. Yield-Enhancing Heterotic QTL Transferred from Wild Species to Cultivated Rice Oryza sativa L

    PubMed Central

    Gaikwad, Kiran B.; Singh, Naveen; Bhatia, Dharminder; Kaur, Rupinder; Bains, Navtej S.; Bharaj, Tajinder S.; Singh, Kuldeep

    2014-01-01

    Utilization of “hidden genes” from wild species has emerged as a novel option for enrichment of genetic diversity for productivity traits. In rice we have generated more than 2000 lines having introgression from ‘A’ genome-donor wild species of rice in the genetic background of popular varieties PR114 and Pusa44 were developed. Out of these, based on agronomic acceptability, 318 lines were used for developing rice hybrids to assess the effect of introgressions in heterozygous state. These introgression lines and their recurrent parents, possessing fertility restoration ability for wild abortive (WA) cytoplasm, were crossed with cytoplasmic male sterile (CMS) line PMS17A to develop hybrids. Hybrids developed from recurrent parents were used as checks to compare the performance of 318 hybrids developed by hybridizing alien introgression lines with PMS17A. Seventeen hybrids expressed a significant increase in yield and its component traits over check hybrids. These 17 hybrids were re-evaluated in large-size replicated plots. Of these, four hybrids, viz., ILH299, ILH326, ILH867 and ILH901, having introgressions from O. rufipogon and two hybrids (ILH921 and ILH951) having introgressions from O. nivara showed significant heterosis over parental introgression line, recurrent parents and check hybrids for grain yield-related traits. Alien introgressions were detected in the lines taken as male parents for developing six superior hybrids, using a set of 100 polymorphic simple sequence repeat (SSR) markers. Percent introgression showed a range of 2.24 from in O. nivara to 7.66 from O. rufipogon. The introgressed regions and their putative association with yield components in hybrids is reported and discussed. PMID:24949743

  9. The Rice Genome Knowledgebase (RGKbase): an annotation database for rice comparative genomics and evolutionary biology

    PubMed Central

    Wang, Dapeng; Xia, Yan; Li, Xinna; Hou, Lixia; Yu, Jun

    2013-01-01

    Over the past 10 years, genomes of cultivated rice cultivars and their wild counterparts have been sequenced although most efforts are focused on genome assembly and annotation of two major cultivated rice (Oryza sativa L.) subspecies, 93-11 (indica) and Nipponbare (japonica). To integrate information from genome assemblies and annotations for better analysis and application, we now introduce a comparative rice genome database, the Rice Genome Knowledgebase (RGKbase, http://rgkbase.big.ac.cn/RGKbase/). RGKbase is built to have three major components: (i) integrated data curation for rice genomics and molecular biology, which includes genome sequence assemblies, transcriptomic and epigenomic data, genetic variations, quantitative trait loci (QTLs) and the relevant literature; (ii) User-friendly viewers, such as Gbrowse, GeneBrowse and Circos, for genome annotations and evolutionary dynamics and (iii) Bioinformatic tools for compositional and synteny analyses, gene family classifications, gene ontology terms and pathways and gene co-expression networks. RGKbase current includes data from five rice cultivars and species: Nipponbare (japonica), 93-11 (indica), PA64s (indica), the African rice (Oryza glaberrima) and a wild rice species (Oryza brachyantha). We are also constantly introducing new datasets from variety of public efforts, such as two recent releases—sequence data from ∼1000 rice varieties, which are mapped into the reference genome, yielding ample high-quality single-nucleotide polymorphisms and insertions–deletions. PMID:23193278

  10. Influence of fipronil compounds and rice-cultivation land-use intensity on macroinvertebrate communities in streams of southwestern Louisiana, USA

    USGS Publications Warehouse

    Mize, S.V.; Porter, S.D.; Demcheck, D.K.

    2008-01-01

    Laboratory tests of fipronil and its degradation products have revealed acute lethal toxicity at very low concentrations (LC50) of <0.5 ??g/L to selected aquatic macroinvertebrates. In streams draining basins with intensive rice cultivation in southwestern Louisiana, USA, concentrations of fipronil compounds were an order of magnitude larger than the LC50. The abundance (?? = -0.64; p = 0.015) and taxa richness (r2 = 0.515, p < 0.005) of macroinvertebrate communities declined significantly with increases in concentrations of fipronil compounds and rice-cultivation land-use intensity. Macroinvertebrate community tolerance scores increased linearly (r2 = 0.442, p < 0.005) with increases in the percentage of rice cultivation in the basins, indicating increasingly degraded stream conditions. Similarly, macroinvertebrate community-tolerance scores increased rapidly as fipronil concentrations approached about 1 ??g/L. Pesticide toxicity index determinations indicated that aquatic macroinvertebrates respond to a gradient of fipronil compounds in water although stream size and habitat cannot be ruled out as contributing influences.

  11. Robustness and Strategies of Adaptation among Farmer Varieties of African Rice (Oryza glaberrima) and Asian Rice (Oryza sativa) across West Africa

    PubMed Central

    Maat, Harro; Richards, Paul; Struik, Paul C.

    2013-01-01

    This study offers evidence of the robustness of farmer rice varieties (Oryza glaberrima and O. sativa) in West Africa. Our experiments in five West African countries showed that farmer varieties were tolerant of sub-optimal conditions, but employed a range of strategies to cope with stress. Varieties belonging to the species Oryza glaberrima – solely the product of farmer agency – were the most successful in adapting to a range of adverse conditions. Some of the farmer selections from within the indica and japonica subspecies of O. sativa also performed well in a range of conditions, but other farmer selections from within these two subspecies were mainly limited to more specific niches. The results contradict the rather common belief that farmer varieties are only of local value. Farmer varieties should be considered by breeding programmes and used (alongside improved varieties) in dissemination projects for rural food security. PMID:23536754

  12. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

    PubMed

    Nuijten, Edwin; van Treuren, Robbert; Struik, Paul C; Mokuwa, Alfred; Okry, Florent; Teeken, Béla; Richards, Paul

    2009-01-01

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo) using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty. PMID:19806197

  13. Natural alleles of a proteasome α2 subunit gene contribute to thermotolerance and adaptation of African rice.

    PubMed

    Li, Xin-Min; Chao, Dai-Yin; Wu, Yuan; Huang, Xuehui; Chen, Ke; Cui, Long-Gang; Su, Lei; Ye, Wang-Wei; Chen, Hao; Chen, Hua-Chang; Dong, Nai-Qian; Guo, Tao; Shi, Min; Feng, Qi; Zhang, Peng; Han, Bin; Shan, Jun-Xiang; Gao, Ji-Ping; Lin, Hong-Xuan

    2015-07-01

    Global warming threatens many aspects of human life, for example, by reducing crop yields. Breeding heat-tolerant crops using genes conferring thermotolerance is a fundamental way to help deal with this challenge. Here we identify a major quantitative trait locus (QTL) for thermotolerance in African rice (Oryza glaberrima), Thermo-tolerance 1 (TT1), which encodes an α2 subunit of the 26S proteasome involved in the degradation of ubiquitinated proteins. Ubiquitylome analysis indicated that OgTT1 protects cells from heat stress through more efficient elimination of cytotoxic denatured proteins and more effective maintenance of heat-response processes than achieved with OsTT1. Variation in TT1 has been selected for on the basis of climatic temperature and has had an important role in local adaptation during rice evolution. In addition, we found that overexpression of OgTT1 was associated with markedly enhanced thermotolerance in rice, Arabidopsis and Festuca elata. This discovery may lead to an increase in crop security in the face of the ongoing threat of global warming. PMID:25985140

  14. [Impact on the Microbial Biomass and Metabolic Function of Carbon Source by Black Soil During Rice Cultivation].

    PubMed

    Zhao, Zhi-rui; Cui, Bing-jian; Hou, Yan-lin; Liu, Shang-qian; Wang, Yan

    2015-08-01

    The effects of rice cultivation to the black soil microbial communities, which the experimentation area of Shuangyang District Agricultural Technology Extension Station in Changchun city, Jilin Province of northeastern China, were studied by using the method of phospholipid fatty acids and Biolog ECO-microplate culture. Results showed that the content of organic matter in space was the highest, fewer in the field, and the minimum in the rhizosphere, that change trend of total nitrogen and organic matter was similar in soil. The quantity of organic matter in summer sample was the highest. The microbial fun6tional diversity was significantly higher in summer than that in spring and autumn and showed no significant difference between spring and autumn. For summer and the lowest in winter, Shannon-Wiener index and Pielou index of the space were higher than the field and the rhizosphere. The time of microbial growth into the stable period and peak value of the average well color development were different in all samples, that the time was 216 h, 192 h, 216 h, 120 h, which varied from 0.52-0.84, 0.82-1.28, 0.40-0.84, 0.05-0.48, respectively. The result showed that the time of microbial growth into the stable period was similar in spring and autumn, the highest was in summer and the lowest was in winter. Above all, these results would provide more important characteristics of microbial features in the degradation and restoration process of the quality of the black soil habitat scientifically. PMID:26592034

  15. Effects of N loading rate on CH4 and N2O emissions during cultivation and fallow periods from forage rice fields fertilized with liquid cattle waste.

    PubMed

    Riya, S; Zhou, S; Kobara, Y; Sagehashi, M; Terada, A; Hosomi, M

    2015-09-15

    The use of liquid cattle waste (LCW) as a fertilizer for forage rice is important for material recycling because it can promote biomass production, and reduce the use of chemical fertilizer. Meanwhile, increase in emission of greenhouse gases (GHGs), especially CH4 and N2O would be concerned. We conducted a field study to determine the optimum loading rate of LCW as N to promote forage rice growth with lower GHG emissions. The LCW was applied to forage rice fields, N100, N250, N500, and N750, at four different N loading rates of 107, 258, 522, and 786 kg N ha(-1), respectively, including 50 kg N ha(-1) of basal chemical fertilizer. The above-ground biomass yields increased 14.6-18.5 t ha(-1) with increases in N loading rates. During the cultivation period, both the CH4 and N2O fluxes increased with increases in LCW loading rates. In the treatments of N100, N250, N500, and N750, the cumulative CH4 emissions during the entire period, including cultivation and fallow period were 29.6, 18.1, 54.4, and 67.5 kg C ha(-1), respectively, whereas those of N2O were -0.15, -0.02, 1.49, and 5.82 kg N ha(-1), respectively. Considering the greenhouse gas emissions and above-ground biomass, the yield-scaled CO2-equivalents (CO2-eqs) were 66.3, 35.9, 161, and 272 kg CO2 t(-1) for N100, N250, N500, and N750, respectively. These results suggest that N250 is the most appropriate LCW loading rate for promoting forage rice production with lower GHG emissions. PMID:26164270

  16. In vitro cultivation of an African strain of Babesia bigemina, its characterisation and infectivity in cattle.

    PubMed

    Posnett, E S; Metaferia, E; Wiliamson, S; Brown, C G; Canning, E U

    1998-01-01

    An African (Kenyan) strain of Babesia bigemina, Muguga (B(2-1)), was inoculated into a calf from a stabilate and blood from the calf was used to establish the parasite in vitro. The strain has been cultured continuously for 20 months, initially in bovine erythrocytes with 60% adult bovine serum, later, with 50%. Cultures were incubated at 37 degrees C in RPMI 1640 medium with a gas mixture of 1% O2, 5% CO2, 94% N2. Adaptation in vitro was demonstrated when serum from a calf which had recovered from infection with B(2-1) bound to proteins of Mr 46 kDa, 49 kDa, 52 kDa, 61 kDa and 72 kDa on Western blots of B(2-1) antigens from cattle blood but did not recognise the 49 kDa or 52 kDa antigens from in-vitro-derived parasites. These proteins were considered specific for B(2-1), as they were not recognised by the same serum on profiles of a Mexican isolate of B. bigemina or an African isolate of B. bovis (Kwanyange). After 9 months of in vitro culture, a stabilate of the cultured parasite was injected into two splenectomised calves and one intact calf. The calves experienced a drop in packed cell volume and low parasitaemias but recovered spontaneously. Two of these animals, one splenectomised and one intact, were challenged with virulent B(2-1) and experienced only mild babesiosis, in contrast to a previously uninfected calf also challenged with B(2-1), which had to be euthanised after 5 days with severe babesiosis. PMID:9569096

  17. Coupling of Belowground Carbon Cycling and Stoichiometry from Organisms to Ecosystems along a Soil C Gradient Under Rice Cultivation

    NASA Astrophysics Data System (ADS)

    Hartman, W.; Ye, R.; Horwath, W. R.; Tringe, S. G.

    2015-12-01

    Ecological stoichiometry is a framework linking biogeochemical cycles to organism functional traits that has been widely applied in aquatic ecosystems, animals and plants, but is poorly explored in soil microbes. We evaluated relationships among soil stoichiometry, carbon (C) cycling, and microbial community structure and function along a soil gradient spanning ~5-25% C in cultivated rice fields with experimental nitrogen (N) amendments. We found rates of soil C turnover were associated with nutrient stoichiometry and phosphorus (P) availability at ecosystem, community, and organism scales. At the ecosystem scale, soil C turnover was highest in mineral soils with lower C content and N:P ratios, and was positively correlated with soil inorganic P. Effects of N fertilization on soil C cycling also appeared to be mediated by soil P availability, while microbial community composition (by 16S rRNA sequencing) was not altered by N addition. Microbial communities varied along the soil C gradient, corresponding with highly covariant soil %C, N:P ratios, C quality, and carbon turnover. In contrast, we observed unambiguous shifts in microbial community function, imputed from taxonomy and directly assessed by shotgun sequenced metagenomes. The abundance of genes for carbohydrate utilization decreased with increasing soil C (and declining C turnover), while genes for aromatic C uptake, N fixation and P scavenging increased along with potential incorporation of C into biomass pools. Ecosystem and community-scale associations between C and nutrient substrate availability were also reflected in patterns of resource allocation among individual genomes (imputed and assembled). Microbes associated with higher rates of soil C turnover harbored more genes for carbohydrate utilization, fewer genes for obtaining energetically costly forms of C, N and P, more ribosomal RNA gene copies, and potentially lower C use efficiency. We suggest genome clustering by functional gene suites might

  18. Red rice (Oryza sativa L.) emergence characteristics and influence on rice (O. sativa) yield at different planting dates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated rice yield losses due to red rice infestation vary by cultivar, red rice density, and duration of interference. The competition effects of red rice could be influenced further by emergence characteristics, red rice biotype, and planting time of cultivated rice. We aimed to characterize th...

  19. Competitive interactions between cultivated and red rice as a function of recent and projected increases in atmospheric carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although carbon dioxide represents a fundamental resource for plant function, increases in atmospheric concentration may differentially stimulate cultivated and weedy types of the same species. Because wild types often represent a weedy constraint to cultivated crops in the field, any differential ...

  20. Comparison of pooled standard deviation and standardized-t bootstrap methods for estimating uncertainty about average methane emission from rice cultivation

    NASA Astrophysics Data System (ADS)

    Kang, Namgoo; Jung, Min-Ho; Jeong, Hyun-Cheol; Lee, Yung-Seop

    2015-06-01

    The general sample standard deviation and the Monte-Carlo methods as an estimate of confidence interval is frequently being used for estimates of uncertainties with regard to greenhouse gas emission, based on the critical assumption that a given data set follows a normal (Gaussian) or statistically known probability distribution. However, uncertainty estimated using those methods are severely limited in practical applications where it is challenging to assume the probability distribution of a data set or where the real data distribution form appears to deviate significantly from statistically known probability distribution models. In order to solve these issues encountered especially in reasonable estimation of uncertainty about the average of greenhouse gas emission, we present two statistical methods, the pooled standard deviation method (PSDM) and the standardized-t bootstrap method (STBM) based upon statistical theories. We also report interesting results of the uncertainties about the average of a data set of methane (CH4) emission from rice cultivation under the four different irrigation conditions in Korea, measured by gas sampling and subsequent gas analysis. Results from the applications of the PSDM and the STBM to these rice cultivation methane emission data sets clearly demonstrate that the uncertainties estimated by the PSDM were significantly smaller than those by the STBM. We found that the PSDM needs to be adopted in many cases where a data probability distribution form appears to follow an assumed normal distribution with both spatial and temporal variations taken into account. However, the STBM is a more appropriate method widely applicable to practical situations where it is realistically impossible with the given data set to reasonably assume or determine a probability distribution model with a data set showing evidence of fairly asymmetric distribution but severely deviating from known probability distribution models.

  1. [Numerical taxonomy of a thermophilic "Bacillus" species isolated from West African rice soils (author's transl)].

    PubMed

    Garcia, J L; Roussos, S; Bensoussan, M; Bianchi, A; Mandel, M

    1982-01-01

    Fifty-seven strains of endospore-forming thermophilic bacteria, 37 of which were capable of denitrification, were isolated from rice soils of West Africa. They were compared with 17 strains of similar bacteria from culture collections, utilizing a total of 123 morphological, physiological and biochemical characteristics. A numerical analysis was performed using the complete linkage-clustering method and the Khi2 test. Seventy-five percent (55 strains) could be included in 12 groups at a taxonomic distance of 0.015. Wild strains of denitrifiers issued in phenons 8 to 12 and strains of phenon 4 (not denitrifying) were related to the named strains of phenons 1 and 7 (Bacillus stearothermophilus). Twenty-two wild strains, and 5 strains from culture collections, were only thermotolerating without growth at 65 degrees C. The strains of phenon 3 were related to the 3 named strains of B. coagulans. Phenons 5 and 6 were composed of strains related to B. circulans. The strains of phenon 2 denitrified and showed a swollen central endospore; they were closely related to B. brevis. The denitrifying thermophilic strains isolated from rice soils (phenons 8 to 12) were related to the first group (B. kaustophilus) of Walker and Wolf but their base compositions of DNA were significantly different from those found for the reference strains. PMID:7103312

  2. Assessing impacts of alternative fertilizer management practices on both nitrogen loading and greenhouse gas emissions in rice cultivation

    NASA Astrophysics Data System (ADS)

    Zhao, Zheng; Yue, Yubo; Sha, Zhimin; Li, Changsheng; Deng, Jia; Zhang, Hanlin; Gao, Maofang; Cao, Linkui

    2015-10-01

    Nitrogen (N) losses and greenhouse gas (GHG) emissions from paddy rice fields contaminate water bodies and atmospheric environment. A 2-year (2012-2013) field experiment was conducted at a typical paddy rice field in a rural suburb of Shanghai, China. N losses and GHG emissions from the paddy field with alternative fertilizer management practices were simultaneously measured. Four treatments were tested in the experiment: applications of only chemical synthetic fertilizer urea (CT), only organic manure (OT), a combination of the two types of fertilizers (MT) and a control (CK). Results from the field study indicated that CT produced the highest seasonal N loading rate (18.79 kg N/ha) and N2O emissions (1.81 kg N2O/ha) but with the lowest seasonal CH4 emissions (69.09 kg CH4/ha). With organic manure applied, MT and OT respectively reduced N loading by 21.86% and 30.41%, reduced N2O emissions by 28.34% and 69.41%, but increased CH4 emissions by 137% and 310% in comparison with CT. However, the net impact of CH4 and N2O emissions on global warming was enhanced when organic manure was applied. In addition, CT and MT produced the optimal rice yield during the experimental period, while OT treatment led to a yield reduction by 9.29% compared with CT. In conclusion, the impacts of alternative fertilizer management practices on ecosystem services ought to be assessed specifically due to the great variations across rice yields, N loss and GHG emissions.

  3. Rice Root Architectural Plasticity Traits and Genetic Regions for Adaptability to Variable Cultivation and Stress Conditions1[OPEN

    PubMed Central

    Sandhu, Nitika; Raman, K. Anitha; Torres, Rolando O.; Audebert, Alain; Dardou, Audrey; Kumar, Arvind; Henry, Amelia

    2016-01-01

    Future rice (Oryza sativa) crops will likely experience a range of growth conditions, and root architectural plasticity will be an important characteristic to confer adaptability across variable environments. In this study, the relationship between root architectural plasticity and adaptability (i.e. yield stability) was evaluated in two traditional × improved rice populations (Aus 276 × MTU1010 and Kali Aus × MTU1010). Forty contrasting genotypes were grown in direct-seeded upland and transplanted lowland conditions with drought and drought + rewatered stress treatments in lysimeter and field studies and a low-phosphorus stress treatment in a Rhizoscope study. Relationships among root architectural plasticity for root dry weight, root length density, and percentage lateral roots with yield stability were identified. Selected genotypes that showed high yield stability also showed a high degree of root plasticity in response to both drought and low phosphorus. The two populations varied in the soil depth effect on root architectural plasticity traits, none of which resulted in reduced grain yield. Root architectural plasticity traits were related to 13 (Aus 276 population) and 21 (Kali Aus population) genetic loci, which were contributed by both the traditional donor parents and MTU1010. Three genomic loci were identified as hot spots with multiple root architectural plasticity traits in both populations, and one locus for both root architectural plasticity and grain yield was detected. These results suggest an important role of root architectural plasticity across future rice crop conditions and provide a starting point for marker-assisted selection for plasticity. PMID:27342311

  4. Cultivating a Morality of Care in African American Adolescents: A Culture-Based Model of Violence Prevention.

    ERIC Educational Resources Information Center

    Ward, Janie V.

    1995-01-01

    Aggression against others violates the care and connectedness implicit in African American racial identity and community culture. Reconnecting youth to communal values and traditions of identity and solidarity may be the solution to youth violence. (SK)

  5. Relationships of wild and domesticated rices (Oryza AA genome species) based upon whole chloroplast genome sequences.

    PubMed

    Wambugu, Peterson W; Brozynska, Marta; Furtado, Agnelo; Waters, Daniel L; Henry, Robert J

    2015-01-01

    Rice is the most important crop in the world, acting as the staple food for over half of the world's population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly supported phylogeny of the AA genome species. The pan tropical distribution of these rice relatives was found to be explained by long distance dispersal within the last million years. The analysis resulted in a clustering pattern that showed strong geographical differentiation. The species were defined in two primary clades with a South American/African clade with two species, O glumaepatula and O longistaminata, distinguished from all other species. The largest clade was comprised of an Australian clade including newly identified taxa and the African and Asian clades. This refined knowledge of the relationships between cultivated rice and the related wild species provides a strong foundation for more targeted use of wild genetic resources in rice improvement and efforts to ensure their conservation. PMID:26355750

  6. Relationships of wild and domesticated rices (Oryza AA genome species) based upon whole chloroplast genome sequences

    PubMed Central

    Wambugu, Peterson W.; Brozynska, Marta; Furtado, Agnelo; Waters, Daniel L.; Henry, Robert J.

    2015-01-01

    Rice is the most important crop in the world, acting as the staple food for over half of the world’s population. The evolutionary relationships of cultivated rice and its wild relatives have remained contentious and inconclusive. Here we report on the use of whole chloroplast sequences to elucidate the evolutionary and phylogenetic relationships in the AA genome Oryza species, representing the primary gene pool of rice. This is the first study that has produced a well resolved and strongly supported phylogeny of the AA genome species. The pan tropical distribution of these rice relatives was found to be explained by long distance dispersal within the last million years. The analysis resulted in a clustering pattern that showed strong geographical differentiation. The species were defined in two primary clades with a South American/African clade with two species, O glumaepatula and O longistaminata, distinguished from all other species. The largest clade was comprised of an Australian clade including newly identified taxa and the African and Asian clades. This refined knowledge of the relationships between cultivated rice and the related wild species provides a strong foundation for more targeted use of wild genetic resources in rice improvement and efforts to ensure their conservation. PMID:26355750

  7. Greenhouse Gas Emissions and Global Warming Potential of Traditional and Diversified Tropical Rice Rotation Systems including Impacts of Upland Crop Management Practices i.e. Mulching and Inter-crop Cultivation

    NASA Astrophysics Data System (ADS)

    Janz, Baldur; Weller, Sebastian; Kraus, David; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-04-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from flooded double-rice systems to the introduction of well-aerated upland crop systems in the dry season. Emissions of methane (CH4) are expected to decrease, while emissions of nitrous oxide (N2O) will increase and soil organic carbon (SOC) stocks will most likely be volatilized in the form of carbon dioxide (CO2). We measured greenhouse gas (GHG) emissions at the International Rice Research Institute (IRRI) in the Philippines to provide a comparative assessment of the global warming potentials (GWP) as well as yield scaled GWPs of different crop rotations and to evaluate mitigation potentials or risks of new management practices i.e. mulching and inter-crop cultivation. New management practices of mulching and intercrop cultivation will also have the potential to change SOC dynamics, thus can play the key role in contributing to the GWP of upland cropping systems. To present, more than three years of continuous measurement data of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation have been collected. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower (p<0.05) annual GWP (CH4+ N2O) as compared to the traditional double-rice cropping system. Measurements of soil organic carbon contents before and three years after introduction of upland

  8. Differentiation of weedy traits in ALS-resistant red rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is a weedy form of cultivated rice (Oryza sativa) that competes aggressively with rice in the southern U.S., reduces yields and contaminates rice grains. The introduction of ClearfieldTM rice, a nontransgenic, herbicide-resistant rice cultivar a decade ago has led to increased use of imazet...

  9. A Qualitative Investigation of African Americans' Decision to Pursue Computing Science Degrees: Implications for Cultivating Career Choice and Aspiration

    ERIC Educational Resources Information Center

    Charleston, LaVar J.

    2012-01-01

    According to Pearson (2002), minority groups are not well represented in science, technology, engineering, and mathematics (STEM) occupations. Among these underrepresented groups are African Americans. To ensure the economic vitality of the STEM workforce in the United States, it is imperative to broaden participation in STEM-related fields and…

  10. Maximum outcrossing rate and genetic compatibility between red rice (Oryza sativa) biotypes and Clearfield™ rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although red rice can be selectively controlled with imazethapyr in ClearfieldTM (CL) rice, the transfer of the imazethapyr-resistant gene from CL rice to red rice is an ecological risk. Previous experiments indicated that flowering synchronization and genetic compatibility between cultivated rice a...

  11. Soil Phosphorus Stoichiometry Drives Carbon Turnover Along a Soil C Gradient Spanning Mineral and Organic Soils Under Rice Cultivation

    NASA Astrophysics Data System (ADS)

    Hartman, W.; Ye, R.; Horwath, W. R.; Tringe, S. G.

    2014-12-01

    Soil carbon (C) cycling is linked to the availability of nutrients like nitrogen (N) and phosphorus (P). However, the role of soil P in influencing soil C turnover and accumulation is poorly understood, with most models focusing on C:N ratios based on the assumption that terrestrial ecosystems are N limited. To determine the effects of N and P availability on soil C turnover, we compared soil respiration over the course of a growing season in four adjacent rice fields with 5%, 10%, 20% and 25% soil C. In each of these fields, plots were established to test the effect of N additions on plant growth, using control and N addition treatments (80 kg N/ha urea). Although soil P was not manipulated in parallel, prior work has shown soil P concentrations decline markedly with increasing soil C content. Soil CO2 flux was monitored using static chambers at biweekly intervals during the growing season, along with porewater dissolved organic C and ammonium. Soils were collected at the end of the growing season, and tested for total C, N, and P, extractable N and P, pH, base cations and trace metals. Soil DNA was also extracted for 16S rRNA sequencing to profile microbial communities. Soil N additions significantly increased CO2 flux and soil C turnover (seasonal CO2 flux per unit soil C) in 5% and 10% C fields, but not in 20% or 25% C fields. Soil C content was closely related to soil N:P stoichiometry, with N:P ratios of ca. 12, 16, 24, and 56 respectively in the 5, 10, 20 and 25% C fields. Seasonal CO2 fluxes (per m2) were highest in 10% C soils. However, soil C turnover was inversely related to soil C concentrations, with the greatest C turnover at the lowest values of soil C. Soil C turnover showed stronger relationships with soil chemical parameters than seasonal CO2 fluxes alone, and the best predictors of soil C turnover were soil total and extractable N:P ratios, along with extractable P alone. Our results show that soil P availability and stoichiometry influence the

  12. Molecular evolution of the sh4 shattering locus in U.S. weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated rice fields worldwide are plagued with weedy rice, a congeneric weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice g...

  13. The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of imazethapyr herbicide-resistant (HR) Clearfield® rice (Oryza sativa L.) to control weedy rice has increased in the past 12 years to comprise about 60% of rice acreage in Arkansas, where 43% of rice in the USA was planted in 2013. To assess the impact of HR cultivated rice on herbicide res...

  14. Factors influencing ALS-resistant gene transfer from CL (tm) rice to red rice.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice (Oryza sativa L.) is hard to control due to its genetic similarity to cultivated rice. Herbicide-resistant Clearfield ™ (CL) rice now offers an excellent option for red rice control. However, sustainability of CL technology at the producers’ level will be dictated by various factors. Promi...

  15. Transfer of herbicide-resistant gene to weedy rice populations and its implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice diversity in terms of phenology, sexual compatibility with cultivated rice, and the wide window of rice planting time can affect the rate of herbicide-resistant gene transfer from rice to RR. Experiments were conducted to a) determine the effect of red rice, rice cultivar, and planting date...

  16. RED RICE DIVERSITY AND PLANTING DATE EFFECTS ON RISK OF GENE FLOW

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice (Oryza sativa L.) is a problematic weed in rice production worldwide. Red rice control is difficult with conventional herbicides due to its similar biology and physiology as cultivated rice. However, herbicide-resistant (HR) rice provides a valuable tool for red rice management, but with a ...

  17. Modeling effects of inter-annual variability in meteorological and land use conditions on coupled water and energy cycling in the cultivated African Sahel

    NASA Astrophysics Data System (ADS)

    Velluet, C.; Demarty, J.; Cappelaere, B.; Braud, I.; Boulain, N.; Favreau, G.; Charvet, G.; Ramier, D.; Issoufou, H.; Boucher, M.; Mainassara, I.; Chazarin, J.; Oï, M.; Yahou, H.; Benarrosh, N.; Ibrahim, M.

    2012-12-01

    In the dry tropics in general and in the African Sahel in particular, hydro-ecosystems are very sensitive to climate variability and land management. In the Niamey region of South-West Niger, a severe multi-decadal drought together with large-scale vegetation clearing coincided with an unexpected increase in surface and ground water resources. Such an apparent paradoxical situation illustrates the complex way in which climate and land cover interactions control the Sahelian water cycle dynamics. This stresses the importance of understanding and reliably modeling water/energy transfers in the local soil-plant-atmosphere system, under contrasted meteorological and surface conditions. This study investigates the effects of the inter-annual variability of meteorological and land use conditions on the coupled water and energy cycles in the cultivated Sahel over a 5-year period. This is based on a comprehensive multi-year field dataset acquired for a millet crop field and a fallow savannah, the two main land cover types of South-West Niger (Wankama catchment in the mesoscale AMMA-CATCH Niger observatory, part of the French-initiated RBV network). It includes atmospheric forcing, seasonal course of vegetation phenology, soil properties and model validation variables (net radiation, turbulent fluxes, soil heat/water profiles), for the two fields. The study area is typical of Central Sahel conditions, with 400-600 mm annual rainfall concentrated in the 4-5 month wet season. Soils are mainly sandy and prone to surface crusting, leading to a strong vertical contrast in hydrodynamic properties. The SiSPAT process-based model used solves the 1D mass and heat transfer system of equations in the soil, including vapor phase and coupled with a two-component (bare soil and vegetation) water and energy budget at the surface-atmosphere interface. The study explores whether such a model can be accurately calibrated and validated for the two sites using realistic-parameter values. The

  18. Understanding of evolutionary genomics of invasive species of rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is an aggressive, weedy form of cultivated rice (Oryza sativa) that infests crop fields and is a primary factor limiting rice productivity in the U.S. and worldwide. As the weedy relative of a genomic model species, red rice is a model for understanding the genetic and evolutionary mechani...

  19. Elucidation of molecular dynamics of invasive species of rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated rice fields are aggressively invaded by weedy rice in the U.S. and worldwide. Weedy rice results in loss of yield and seed contamination. The molecular dynamics of the evolutionary adaptive traits of weedy rice are not fully understood. To understand the molecular basis and identify the i...

  20. Identifying novel resistance genes in rice wild relatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast and sheath blight are major fungal diseases of cultivated rice (Oryza sativa L. ) that limit Arkansas rough rice yields and market potential. Resistance to these diseases has been found in rice wild relatives (Oryza spp.) A collection of these wild relatives originating from outside the U...

  1. TAL effectors and activation of predicted host targets distinguish Asian from African strains of the rice pathogen Xanthomonas oryzae pv. oryzicola while strict conservation suggests universal importance of five TAL effectors

    PubMed Central

    Wilkins, Katherine E.; Booher, Nicholas J.; Wang, Li; Bogdanove, Adam J.

    2015-01-01

    Xanthomonas oryzae pv. oryzicola (Xoc) causes the increasingly important disease bacterial leaf streak of rice (BLS) in part by type III delivery of repeat-rich transcription activator-like (TAL) effectors to upregulate host susceptibility genes. By pathogen whole genome, single molecule, real-time sequencing and host RNA sequencing, we compared TAL effector content and rice transcriptional responses across 10 geographically diverse Xoc strains. TAL effector content is surprisingly conserved overall, yet distinguishes Asian from African isolates. Five TAL effectors are conserved across all strains. In a prior laboratory assay in rice cv. Nipponbare, only two contributed to virulence in strain BLS256 but the strict conservation indicates all five may be important, in different rice genotypes or in the field. Concatenated and aligned, TAL effector content across strains largely reflects relationships based on housekeeping genes, suggesting predominantly vertical transmission. Rice transcriptional responses did not reflect these relationships, and on average, only 28% of genes upregulated and 22% of genes downregulated by a strain are up- and down- regulated (respectively) by all strains. However, when only known TAL effector targets were considered, the relationships resembled those of the TAL effectors. Toward identifying new targets, we used the TAL effector-DNA recognition code to predict effector binding elements in promoters of genes upregulated by each strain, but found that for every strain, all upregulated genes had at least one. Filtering with a classifier we developed previously decreases the number of predicted binding elements across the genome, suggesting that it may reduce false positives among upregulated genes. Applying this filter and eliminating genes for which upregulation did not strictly correlate with presence of the corresponding TAL effector, we generated testable numbers of candidate targets for four of the five strictly conserved TAL

  2. Diversity in grain physico-chemical characteristics of West African rice, including Nerica genotypes, as compared to cultivars from the United States of America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Landraces from West Africa (WA), NERICA progenies derived from crosses between Oryza sativa and Oryza glaberrima, and improved O. sativa lines from Africa Rice Center were introduced to the Beaumont Rice Research Center in Texas, United States of America (USA) (29 degrees 57’ N and 94 degrees 30’ W)...

  3. Changes in CH4 emission from rice fields from 1960 to 1990s. 1. Impacts of modern rice technology

    NASA Astrophysics Data System (ADS)

    van der Gon, Hugo Denier

    2000-03-01

    Four countries (Indonesia, Philippines, Thailand, and Nepal) were taken as an example to assess the impact of changes in rice cultivation on methane emissions from rice fields since the 1960s. The change of rice area by type of culture from 1960-1990s is estimated, and its relative contribution to national harvested rice area is calculated and multiplied with an emission factor, to derive the relative methane emission per unit rice land. Relative methane emission per ha rice land has increased since 1960 for all four countries, largely due to an increase in irrigated rice area and partly due to a decrease in upland rice area. Patterns of rice area changes and related emission changes differ considerably among countries. On the basis of the rice area increases between 1960 and the 1990s, significant increases in methane emissions from rice fields due to increases in total rice cultivated area are not to be expected in the future. The impact of modern rice variety adoption is assessed by relating methane emissions to rice production. The organic matter returned to the paddy soil is largely determined by rice biomass production which, given a certain yield, is different for traditional and modern rice varieties. By calculating total organic matter returned to rice paddy soils and assuming a constant fraction to be emitted as methane, rice production and methane emission can be related. The analysis indicates that (1) up to now, rice yield increases in countries with high modern rice variety adoption have not resulted in increased methane emissions per unit of harvested area and, (2) global annual emission from rice fields may be considerably lower than generally assumed. The introduction of modern rice varieties can be regarded as a historical methane emission mitigation strategy because higher rice yields resulted in lower or equal methane emissions.

  4. Changes in CH4 emission from rice fields from 1960 to 1990s: 1. Impacts of modern rice technology

    NASA Astrophysics Data System (ADS)

    Gon, Hugo Denier

    2000-03-01

    Four countries (Indonesia, Philippines, Thailand, and Nepal) were taken as an example to assess the impact of changes in rice cultivation on methane emissions from rice fields since the 1960s. The change of rice area by type of culture from 1960-1990s is estimated, and its relative contribution to national harvested rice area is calculated and multiplied with an emission factor, to derive the relative methane emission per unit rice land. Relative methane emission per ha rice land has increased since 1960 for all four countries, largely due to an increase in irrigated rice area and partly due to a decrease in upland rice area. Patterns of rice area changes and related emission changes differ considerably among countries. On the basis of the rice area increases between 1960 and the 1990s, significant increases in methane emissions from rice fields due to increases in total rice cultivated area are not to be expected in the future. The impact of modern rice variety adoption is assessed by relating methane emissions to rice production. The organic matter returned to the paddy soil is largely determined by rice biomass production which, given a certain yield, is different for traditional and modern rice varieties. By calculating total organic matter returned to rice paddy soils and assuming a constant fraction to be emitted as methane, rice production and methane emission can be related. The analysis indicates that (1) up to now, rice yield increases in countries with high modern rice variety adoption have not resulted in increased methane emissions per unit of harvested area and, (2) global annual emission from rice fields may be considerably lower than generally assumed. The introduction of modern rice varieties can be regarded as a historical methane emission mitigation strategy because higher rice yields resulted in lower or equal methane emissions.

  5. 4th Annual Conference for African-American Researchers in the Mathematical Sciences (CAARMS4). Preliminary Program

    SciTech Connect

    Tapia, Richard

    1998-06-01

    In June, The Center for Research on Parallel Computation (CRPC), an NSF-funded Science and Technology Center, hosted the 4th Annual Conference for African-American Reserachers in the Mathematical Sciences (CAARMS4) at Rice University. The main goal of this conference was to highlight current work by African-American researchers and graduate students in mathematics. This conference strengthened the mathematical sciences by encouraging the increased participation of African-American and underrepresented groups into the field, facilitating working relationships between them and helping to cultivate their careers. In addition to the talks there was a graduate student poster session and tutorials on topics in mathematics and computer science. These talks, presentations, and discussions brought a broader perspective to the critical issues involving minority participation in mathematics.

  6. Origins and evolution of weedy rice in the US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is a weedy form of cultivated rice (Oryza sativa) that infests crop fields and reduces US rice harvests by up to 80%. This agricultural weed has been proposed to arise either through de-domestication of feral US crop germplasm and/or introduction of foreign germplasm (potentially including ...

  7. Molecular evolution of the rice blast resistance gene Pi-ta in invasive weedy rice in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pi-ta gene has been effectively used to control rice blast disease caused by Magnaporthe oryzae in many rice growing regions in the world. A number of studies have characterized the molecular evolution of the Pi-ta gene in cultivated rice, O. sativa, and its wild ancestor O. rufipogon; however,...

  8. Evolutionary Genomics Of Invasive Weedy Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is an interfertile, weedy form of cultivated rice (Oryza sativa) that competes aggressively with the crop in the southern U.S., reducing yields and contaminating harvests. Weed strains range from ‘crop mimics,’ which share many domestication traits with the crop, to strains closely resembli...

  9. Connecting with Rice: Carolina Lowcountry and Africa

    ERIC Educational Resources Information Center

    Mitchell, Jerry T.; Collins, Larianne; Wise, Susan S.; Caughman, Monti

    2012-01-01

    Though lasting less than 200 years, large-scale rice production in South Carolina and Georgia "probably represented the most significant utilization of the tidewater zone for crop agriculture ever attained in the United States." Rice is a specialty crop where successful cultivation relied heavily upon "adaptation" to nature via imported…

  10. Process Integration for the Disruption of Candida guilliermondii Cultivated in Rice Straw Hydrolysate and Recovery of Glucose-6-Phosphate Dehydrogenase by Aqueous Two-Phase Systems.

    PubMed

    Gurpilhares, Daniela B; Pessoa, Adalberto; Roberto, Inês C

    2015-07-01

    Remaining cells of Candida guilliermondii cultivated in hemicellulose-based fermentation medium were used as intracellular protein source. Recovery of glucose-6-phosphate dehydrogenase (G6PD) was attained in conventional aqueous two-phase systems (ATPS) was compared with integrated process involving mechanical disruption of cells followed by ATPS. Influences of polyethylene glycol molar mass (M PEG) and tie line lengths (TLL) on purification factor (PF), yields in top (Y T ) and bottom (Y B ) phases and partition coefficient (K) were evaluated. First scheme resulted in 65.9 % enzyme yield and PF of 2.16 in salt-enriched phase with clarified homogenate (M PEG 1500 g mol(-1), TLL 40 %); Y B of 75.2 % and PF B of 2.9 with unclarified homogenate (M PEG 1000 g mol(-1), TLL 35 %). The highest PF value of integrated process was 2.26 in bottom phase (M PEG 1500 g mol(-1), TLL 40 %). In order to optimize this response, a quadratic model was predicted for the response PFB for process integration. Maximum response achieved was PFB = 3.3 (M PEG 1500 g mol(-1), TLL 40 %). Enzyme characterization showed G6P Michaelis-Menten constant (K M ) equal 0.07-0.05, NADP(+) K M 0.02-1.98 and optimum temperature 70 °C, before and after recovery. Overall, our data confirmed feasibility of disruption/extraction integration for single-step purification of intracellular proteins from remaining yeast cells. PMID:25987135

  11. Molecular evolution of flowering time loci in U.S. weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy rice is a persistent weed of cultivated rice (Oryza sativa) fields worldwide, which competes with the crop and drastically reduces rice yields. Within the US, two main populations of genetically differentiated weedy rice exist, the straw-hulled (SH) group and the black-hulled awned (BHA) grou...

  12. Microbial community response to two water management systems for wetland rice production in high arsenic soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice cultivation on arsenic (As) impacted soils has recently garnered considerable attention. Rice plants can accumulate As in grain, especially under the continuously flooded conditions commonly utilized in wetland-rice production. However, recent studies have indicated that rice-management system...

  13. QTLs analysis for resistance to blast disease in US weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the genetic architecture of adaptation is of great importance in evolutionary biology. US weedy rice is well-adapted to the local conditions in US rice fields. Rice blast disease is one of the most destructive diseases of cultivated rice worldwide. However, information about resistance...

  14. Saturated Molecular Map of the Rice Genome Based on an Interspecific Backcross Population

    PubMed Central

    Causse, M. A.; Fulton, T. M.; Cho, Y. G.; Ahn, S. N.; Chunwongse, J.; Wu, K.; Xiao, J.; Yu, Z.; Ronald, P. C.; Harrington, S. E.; Second, G.; McCouch, S. R.; Tanksley, S. D.

    1994-01-01

    A molecular map has been constructed for the rice genome comprised of 726 markers (mainly restriction fragment length polymorphisms; RFLPs). The mapping population was derived from a backcross between cultivated rice, Oryza sativa, and its wild African relative, Oryza longistaminata. The very high level of polymorphism between these species, combined with the use of polymerase chain reaction-amplified cDNA libraries, contributed to mapping efficiency. A subset of the probes used in this study was previously used to construct an RFLP map derived from an inter subspecific cross, providing a basis for comparison of the two maps and of the relative mapping efficiencies in the two crosses. In addition to the previously described PstI genomic rice library, three cDNA libraries from rice (Oryza), oat (Avena) and barley (Hordeum) were used in this mapping project. Levels of polymorphism detected by each and the frequency of identifying heterologous sequences for use in rice mapping are discussed. Though strong reproductive barriers isolate O. sativa from O. longistaminata, the percentage of markers showing distorted segregation in this backcross population was not significantly different than that observed in an intraspecific F(2) population previously used for mapping. The map contains 1491 cM with an average interval size of 4.0 cM on the framework map, and 2.0 cM overall. A total of 238 markers from the previously described PstI genomic rice library, 250 markers from a cDNA library of rice (Oryza), 112 cDNA markers from oat (Avena), and 20 cDNA markers from a barley (Hordeum) library, two genomic clones from maize (Zea), 11 microsatellite markers, three telomere markers, eleven isozymes, 26 cloned genes, six RAPD, and 47 mutant phenotypes were used in this mapping project. Applications of a molecular map for plant improvement are discussed. PMID:7896104

  15. Uncovering a Nuisance Influence of a Phenological Trait of Plants Using a Nonlinear Structural Equation: Application to Days to Heading and Culm Length in Asian Cultivated Rice (Oryza Sativa L.).

    PubMed

    Onogi, Akio; Ideta, Osamu; Yoshioka, Takuma; Ebana, Kaworu; Yamasaki, Masanori; Iwata, Hiroyoshi

    2016-01-01

    Phenological traits of plants, such as flowering time, are linked to growth phase transition. Thus, phenological traits often influence other traits through the modification of the duration of growth period. This influence is a nuisance in plant breeding because it hampers genetic evaluation of the influenced traits. Genetic effects on the influenced traits have two components, one that directly affects the traits and one that indirectly affects the traits via the phenological trait. These cannot be distinguished by phenotypic evaluation and ordinary linear regression models. Consequently, if a phenological trait is modified by introgression or editing of the responsible genes, the phenotypes of the influenced traits can change unexpectedly. To uncover the influence of the phenological trait and evaluate the direct genetic effects on the influenced traits, we developed a nonlinear structural equation (NSE) incorporating a nonlinear influence of the phenological trait. We applied the NSE to real data for cultivated rice (Oryza sativa L.): days to heading (DH) as a phenological trait and culm length (CL) as the influenced trait. This showed that CL of the cultivars that showed extremely early heading was shortened by the strong influence of DH. In a simulation study, it was shown that the NSE was able to infer the nonlinear influence and direct genetic effects with reasonable accuracy. However, the NSE failed to infer the linear influence in this study. When no influence was simulated, an ordinary bi-trait linear model (OLM) tended to infer the genetic effects more accurately. In such cases, however, by comparing the NSE and OLM using an information criterion, we could assess whether the nonlinear assumption of the NSE was appropriate for the data analyzed. This study demonstrates the usefulness of the NSE in revealing the phenotypic influence of phenological traits. PMID:26859143

  16. Uncovering a Nuisance Influence of a Phenological Trait of Plants Using a Nonlinear Structural Equation: Application to Days to Heading and Culm Length in Asian Cultivated Rice (Oryza Sativa L.)

    PubMed Central

    Onogi, Akio; Ideta, Osamu; Yoshioka, Takuma; Ebana, Kaworu; Yamasaki, Masanori; Iwata, Hiroyoshi

    2016-01-01

    Phenological traits of plants, such as flowering time, are linked to growth phase transition. Thus, phenological traits often influence other traits through the modification of the duration of growth period. This influence is a nuisance in plant breeding because it hampers genetic evaluation of the influenced traits. Genetic effects on the influenced traits have two components, one that directly affects the traits and one that indirectly affects the traits via the phenological trait. These cannot be distinguished by phenotypic evaluation and ordinary linear regression models. Consequently, if a phenological trait is modified by introgression or editing of the responsible genes, the phenotypes of the influenced traits can change unexpectedly. To uncover the influence of the phenological trait and evaluate the direct genetic effects on the influenced traits, we developed a nonlinear structural equation (NSE) incorporating a nonlinear influence of the phenological trait. We applied the NSE to real data for cultivated rice (Oryza sativa L.): days to heading (DH) as a phenological trait and culm length (CL) as the influenced trait. This showed that CL of the cultivars that showed extremely early heading was shortened by the strong influence of DH. In a simulation study, it was shown that the NSE was able to infer the nonlinear influence and direct genetic effects with reasonable accuracy. However, the NSE failed to infer the linear influence in this study. When no influence was simulated, an ordinary bi-trait linear model (OLM) tended to infer the genetic effects more accurately. In such cases, however, by comparing the NSE and OLM using an information criterion, we could assess whether the nonlinear assumption of the NSE was appropriate for the data analyzed. This study demonstrates the usefulness of the NSE in revealing the phenotypic influence of phenological traits. PMID:26859143

  17. Acute toxic effects of the herbicide formulation and the active ingredient used in cycloxydim-tolerant maize cultivation on embryos and larvae of the African clawed frog, Xenopus laevis.

    PubMed

    Wagner, Norman; Lötters, Stefan; Veith, Michael; Viertel, Bruno

    2015-04-01

    Most genetically engineered herbicide-tolerant crops are still awaiting approval in Europe. There is, however, a recent trend for the cultivation of cycloxydim-tolerant maize hybrids for use in maize production. We studied the acute toxic effects of the complementary herbicide Focus(®) Ultra and its active ingredient cycloxydim on embryos and early-stage larvae of the African clawed frog (Xenopus laevis). The results indicate that the herbicide formulation is significantly more toxic than the active ingredient alone. Therefore, it is suggested that the added substances either solely or in a synergistic action with the active ingredient are responsible for adverse effects. The formulation was found to be moderately toxic to embryos but highly toxic to early larvae. Based on calculated teratogenic indices, both cycloxydim and Focus(®) Ultra seem to be non-teratogenic and also the minimum Focus(®) Ultra concentration to inhibit growth in embryos and larvae was close to the LC50 values. The data suggest that tests with the rainbow trout are not in all cases appropriate to assess the risk in aquatically developing anurans. This is demonstrated by 96-h LC50 values, which are for rainbow trout more than 50- to 20-fold higher than for early X. laevis larvae. However, based on worst-case predicted environmental concentrations for surface waters, there is apparently a large safety margin in field use of Focus(®) Ultra if buffer strips between the farm land and the amphibian habitats are regarded. PMID:25634323

  18. Rice Methylmercury Exposure and Mitigation: A Comprehensive Review

    PubMed Central

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effect of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, which minimize methylmercury exposure through rice ingestion. PMID:24972509

  19. Rice methylmercury exposure and mitigation: a comprehensive review

    USGS Publications Warehouse

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  20. Rice methylmercury exposure and mitigation: a comprehensive review.

    PubMed

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion. PMID:24972509

  1. The impact of volunteer rice infestation on rice yield and grain quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volunteer rice (Oryza sativa L.) is a crop stand which emerges from shattered seeds of the previous crop. When present at sufficiently high levels, it can potentially affect the commercial market value of cultivated rice products, especially if it produces kernels with quality, uniformity, or size ...

  2. High IgE sensitization to maize and rice pollen in the highlands of Madagascar

    PubMed Central

    Ramavovololona; Sénéchal, Hélène; Andrianarisoa, Ange; Rakotoarimanana, Vololona; Godfrin, Dominique; Peltre, Gabriel; Poncet, Pascal; Sutra, Jean-Pierre

    2014-01-01

    Introduction Maize and rice are two crops constituting the main food supply in many under-developed and developing countries. Despite the large area devoted to the culture, the sensitization to the pollen from these plants is reported to be low and often considered as an occupational allergy. Methods Sixty five Malagasy pollen allergic patients were clinically and immunochemically investigated with regard to maize and rice pollen allergens. Pollen extracts were electrophoretically separated in 1 and 2 dimensions and IgE and IgG reactivities detected upon immunoblotting. Results When exploring the sensitization profile of Malagasy allergic patients to maize and rice pollen, it appears that a high proportion of these patients consulting during grass pollinating season were sensitized to both pollen as revealed by skin prick testing (62 vs. 59%) and IgE immunoblotting (85 vs. 40%). Several clinically relevant allergens were recognized by patients’ serum IgE in maize and rice pollen extracts. Conclusion The high levels of maize and rice pollen sensitization should be related, in this tropical region, to a specific environmental exposure including i) a proximity of the population to the allergenic sources and ii) a putative exacerbating effect of a highly polluted urban atmosphere on pollen allergenicity. Cross-reactivities between wild and cultivated grasses and also between rice and maize pollen are involved as well as some specific maize sensitizations. The presence of dense urban and peri-urban agriculture, in various African regions and worldwide, could be a high environmental risk factor for people sensitive to maize pollen. PMID:25870739

  3. [Rice: source of life and death on the plateaux of Madagascar].

    PubMed

    Laventure, S; Mouchet, J; Blanchy, S; Marrama, L; Rabarison, P; Andrianaivolambo, L; Rajaonarivelo, E; Rakotoarivony, I; Roux, J

    1996-01-01

    Since the 17th century, Europeans travelling in Madagascar described the contrast between the fever-free Plateau and the fever-ridden coasts. The former were inhabited by people of Asiatic origins and the latter by African migrants. At the end of the 18th century, "Merina" kings developed land irrigation and rice cultivation, using manpower from the coasts. Since then, rice has become a monoculture covering most of the arable lands of the Highlands. The first malaria epidemic occurred in the Tananarive area in 1878, and rapidly spread throughout the Plateau. The mortality rate was high. A second epidemic in 1895 may have been a resurgence of the previous one. Subsequently, malaria became meso-epidemic despite control measures, mainly consisting of larvivorous fishes, quinine treatment and prophylaxis. In 1949, an eradication program was launched based on DDT house-spraying and chloroquine prophylaxis in children. It was very successful on the Highlands where malaria disappeared, in 1962. Spraying was cancelled and only three small foci remained under surveillance. In 1987 and 1988, a malaria outbreak devastated the plateau. Subsequently, intensive spraying operations brought the situation under control by 1993. The main malaria vector on the Madagascar Highlands is An. funestus. More than 95% of its breeding sites are in the rice fields just before the harvest and afterwards in the fallow lands. The vector peak and the corresponding peak of malaria cases occur between February and May, depending on the farming calender. The second but less important vector, An. arabiensis, breeds in the rice fields just after seeding when the surface water is sunlit. Although rice fields remain the main source of this vector, it also breeds in rainwater pods and borow-pits. Malaria vectors on the plateau are products of human activities of rice cultivation, which is the basis of the economy. The epidemiological importance of rice fields varies greatly from one country to another

  4. Identification of Sheath Blight Resistance QTLs in Rice Using Recombinant Inbred Line Population of Lemont X Jasmine 85

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice sheath blight (RSB) caused by the soil borne pathogen Rhizoctonia solani, is one of the most destructive diseases of rice around the globe, causing severe losses in rice yield and quality annually. Major gene(s) governing the resistance to RSB have not been found in cultivated rice worldwide...

  5. Rice Domestication Revealed by Reduced Shattering of Archaeological rice from the Lower Yangtze valley

    PubMed Central

    Zheng, Yunfei; Crawford, Gary W.; Jiang, Leping; Chen, Xugao

    2016-01-01

    Plant remains dating to between 9000 and 8400 BP from a probable ditch structure at the Huxi site include the oldest rice (Oryza sativa) spikelet bases and associated plant remains recovered in China. The remains document an early stage of rice domestication and the ecological setting in which early cultivation was taking place. The rice spikelet bases from Huxi include wild (shattering), intermediate, and domesticated (non-shattering) forms. The relative frequency of intermediate and non-shattering spikelet bases indicates that selection for, at the very least, non-shattering rice was underway at Huxi. The rice also has characteristics of japonica rice (Oryza sativa subsp. japonica), helping to clarify the emergence of a significant lineage of the crop. Seeds, phytoliths and their context provide evidence of increasing anthropogenesis and cultivation during the occupation. Rice spikelet bases from Kuahuqiao (8000–7700 BP), Tianluoshan (7000–6500 BP), Majiabang (6300–6000 BP), and Liangzhu (5300–4300 BP) sites indicate that rice underwent continuing selection for reduced shattering and japonica rice characteristics, confirming a prolonged domestication process for rice. PMID:27324699

  6. Rice Domestication Revealed by Reduced Shattering of Archaeological rice from the Lower Yangtze valley.

    PubMed

    Zheng, Yunfei; Crawford, Gary W; Jiang, Leping; Chen, Xugao

    2016-01-01

    Plant remains dating to between 9000 and 8400 BP from a probable ditch structure at the Huxi site include the oldest rice (Oryza sativa) spikelet bases and associated plant remains recovered in China. The remains document an early stage of rice domestication and the ecological setting in which early cultivation was taking place. The rice spikelet bases from Huxi include wild (shattering), intermediate, and domesticated (non-shattering) forms. The relative frequency of intermediate and non-shattering spikelet bases indicates that selection for, at the very least, non-shattering rice was underway at Huxi. The rice also has characteristics of japonica rice (Oryza sativa subsp. japonica), helping to clarify the emergence of a significant lineage of the crop. Seeds, phytoliths and their context provide evidence of increasing anthropogenesis and cultivation during the occupation. Rice spikelet bases from Kuahuqiao (8000-7700 BP), Tianluoshan (7000-6500 BP), Majiabang (6300-6000 BP), and Liangzhu (5300-4300 BP) sites indicate that rice underwent continuing selection for reduced shattering and japonica rice characteristics, confirming a prolonged domestication process for rice. PMID:27324699

  7. Rice production in relation to soil quality under different rice-based cropping systems

    NASA Astrophysics Data System (ADS)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P < 0.01) between rice plant parameters, rice yield and soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal

  8. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  9. Using a rice diversity panel for association mapping and it's validation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated Asian rice (Oryza sativa L.) has tremendous phenotypic and genotypic diversity that traces back to ancient times. A "Rice Diversity Panel" composed of 413 diverse rice accessions from 82 countries was assembled to explore this genotypic and phenotypic variation. The objectives of this s...

  10. Finding high yield genes in weedy red rice to improve new cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice (Oryza rufipogon) is a weedy, wild relative of cultivated rice (Oryza sativa) that is considered a major pest in rice production fields. However, researchers have found that it can be a valuable source of disease and insect resistance genes. Researchers with USDA ARS and Cornell University ...

  11. Geographic description of genetic diversity and genetic relationships in the USDA Rice World Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) is structured into five genetic groups, indica, AUS, tropical japonica, temperate japonica and aromatic. Genetic characterization of a global rice collection could help better serve the global research community. Collecting worldwide rice germplasm started in ...

  12. Identification of quantitative trait loci (QTLs) responsible for sheath blight resistance in rice using recombinant inbred line population of Lemont X Jasmine 85

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice sheath blight (RSB) caused by the soil borne pathogen Rhizoctonia solani, is one of the most destructive diseases of rice, causing severe losses in rice yield and quality annually. The major gene (s) governing the resistance to RSB have not been found in cultivated rice worldwide. However, ri...

  13. A natural mutation in rc reverts white-pericarp-rice to red and results is a new, dominant, wild-type allele Rc-g

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The occurrence of grain with red pericarp in rice production is normal where red rice is a common weed problem. Classic weedy red rice can usually be distinguished morphologically without the need to de-hull seed to reveal pericarp color. However, rice with red pericarp is also found in cultivated ...

  14. Processes of diversification and dispersion of rice yellow mottle virus inferred from large-scale and high-resolution phylogeographical studies.

    PubMed

    Traore, O; Sorho, F; Pinel, A; Abubakar, Z; Banwo, O; Maley, J; Hebrard, E; Winter, S; Sere, Y; Konate, G; Fargette, D

    2005-06-01

    Phylogeography of Rice yellow mottle virus (RYMV) was reconstructed from the coat protein gene sequences of a selection of 173 isolates from the 14 countries of mainland Africa where the disease occurred and from the full sequences of 16 representative isolates. Genetic variation was linked to geographical distribution and not to host species as isolates from wild rice always clustered with isolates from cultivated rice of the same region. Genetic variation was not associated to agro-ecology, viral interference and insect vector species. Distinct RYMV lineages occurred in East, Central and West Africa, although the Central African lineage included isolates from Benin, Togo and Niger at the west, adjacent to countries of the West African lineage. Genetic subdivision at finer geographical scales was apparent within lineages of Central and West Africa, although less pronounced than in East Africa. Physical obstacles, but also habitat fragmentation, as exemplified by the small low-lying island of Pemba offshore Tanzania mainland, explained strain localization. Three new highly divergent strains were found in eastern Tanzania. By contrast, intensive surveys in Cote d'Ivoire and Guinea at the west of Africa did not reveal any new variant. Altogether, this supported the view that the Eastern Arc Mountains biodiversity hotspot was the centre of origin of RYMV and that the virus spread subsequently from east to west across Africa. In West Africa, specific strains occurred in the Inner Niger Delta and suggested it was a secondary centre of diversification. Processes for diversification and dispersion of RYMV are proposed. PMID:15910330

  15. Response of aerobic rice to Piriformospora indica.

    PubMed

    Das, Joy; Ramesh, K V; Maithri, U; Mutangana, D; Suresh, C K

    2014-03-01

    Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomusfasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P. indica resembling "Mayan temple" was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza. PMID:24669667

  16. Rice, indica (Oryza sativa L.).

    PubMed

    Hiei, Yukoh; Ishida, Yuji; Komari, Toshihiko

    2015-01-01

    Indica varieties, which are generally recalcitrant to tissue culture and transformation, occupy 80 % of rice cultivation area in the world. Therefore, transformation method for indica rice must be improved greatly so that global rice production would take full advantage of cutting-edge biotechnology. An efficient protocol for indica transformation mediated by Agrobacterium tumefaciens is hereby described. Immature embryos collected from plants in a greenhouse are cocultivated with A. tumefaciens after pretreatment with heat and centrifuging. The protocol was successfully tested in many elite indica cultivars such as IR8, IR24, IR58025B, IR64, IR72, Suweon 258, and Nanjing 11, yielding between 5 and 15 of independent transgenic plants per immature embryo. The use of immature embryos is recommended because gene transfer to them could be much more efficient and much less genotype dependent than gene transfer to callus. PMID:25300838

  17. Rice Nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter presents the symptoms of deficiency and toxicity of the major and minor mineral nutrients in rice, as well as a current synopsis of nutrient transporters and their regulation. The availability of sequences from the recently completed rice genome has furthered the knowledge of how plants...

  18. Taste of Super-Dwarf Rice Cultured in Space

    NASA Astrophysics Data System (ADS)

    Hirai, Hiroaki; Kitaya, Yoshiaki

    2016-07-01

    The interest of food production for lunar base and manned Mars mission has increased recently. So far, plants cultured long duration in space were leafy vegetables, arabidopsis, wheat, barley and so on. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. Rice symbolizes the rice-eating culture of Japan, is extremely useful as a specific cultured plant candidate of Japan in space. In the previous report, 'Kozo-no-sumika' found from seedlings in raising of seedling was introduced as a super-dwarf rice to culture in space. Considering this rice as food in space, we investigate the taste characteristics of this rice. At present, waxy 'Kozo-no-sumika' and nonwaxy 'Hosetsu dwarf' of super-dwarf rice and 'Nipponbare' of previous standard rice for sensory test are cultured in paddy field. Hereafter, we will harvest rice, investigate yield, evaluate taste.

  19. Evolutionary and social consequences of introgression of nontransgenic herbicide resistance from rice to weedy rice in Brazil.

    PubMed

    Merotto, Aldo; Goulart, Ives C G R; Nunes, Anderson L; Kalsing, Augusto; Markus, Catarine; Menezes, Valmir G; Wander, Alcido E

    2016-08-01

    Several studies have expressed concerns about the effects of gene flow from transgenic herbicide-resistant crops to their wild relatives, but no major problems have been observed. This review describes a case study in which what has been feared in transgenics regarding gene flow has actually changed biodiversity and people's lives. Nontransgenic imidazolinone-resistant rice (IMI-rice) cultivars increased the rice grain yield by 50% in southern Brazil. This increase was beneficial for life quality of the farmers and also improved the regional economy. However, weedy rice resistant to imidazolinone herbicides started to evolve three years after the first use of IMI-rice cultivars. Population genetic studies indicate that the herbicide-resistant weedy rice was mainly originated from gene flow from resistant cultivars and distributed by seed migration. The problems related with herbicide-resistant weedy rice increased the production costs of rice that forced farmers to sell or rent their land. Gene flow from cultivated rice to weedy rice has proven to be a large agricultural, economic, and social constraint in the use of herbicide-resistant technologies in rice. This problem must be taken into account for the development of new transgenic or nontransgenic rice technologies. PMID:27468302

  20. Water Management Practices Affect Arsenic and Cadmium Accumulation in Rice Grains

    PubMed Central

    Liu, Hongyan; Peng, Shaobing; Huang, Jianliang; Cui, Kehui

    2014-01-01

    Cadmium (Cd) and arsenic (As) accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded) on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously. PMID:25013859

  1. Moulds and mycotoxins in rice from the Swedish retail market.

    PubMed

    Fredlund, E; Thim, A-M; Gidlund, A; Brostedt, S; Nyberg, M; Olsen, M

    2009-04-01

    A survey of moulds and mycotoxins was performed on 99 rice samples taken from the Swedish retail market. The main objective was to study the mould and mycotoxin content in basmati rice and rice with a high content of fibre. Samples of jasmine rice as well as long-grain rice were also included. The samples were analysed for their content of ochratoxin A (high-performance liquid chromatography (HPLC)), aflatoxin B(1), B(2), G(1), and G(2) (HPLC, RIDA(R)QUICK), and mould (traditional cultivation methods in combination with morphological analysis). The majority of samples were sampled according to European Commission Regulation 401/2006. Subsamples were pooled and mixed before milling and both mould and mycotoxin analyses were performed on milled rice. The results showed that the majority of basmati rice (71%) and many jasmine rice samples (20%) contained detectable levels of aflatoxin B(1) (level of quantification = 0.1 microg aflatoxin kg(-1) rice). Two samples of jasmine rice and ten basmati rice samples contained levels over the regulated European maximum limits of 2 microg kg(-1) for aflatoxin B(1) or 4 microg kg(-1) for total aflatoxins. Aspergillus was the most common mould genus isolated, but also Penicillium, Eurotium, Wallemia, Cladosporium, Epicoccum, Alternaria, and Trichotecium were found. The presence of Aspergillus flavus in 21% of the samples indicates that incorrect management of rice during production and storage implies a risk of mould growth and subsequent production of aflatoxin. Rough estimates showed that high rice consumers may have an intake of 2-3 ng aflatoxin kg(-1) bodyweight and day(-1) from rice alone. This survey shows that aflatoxin is a common contaminant in rice imported to Europe. PMID:19680928

  2. 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

  3. The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice.

    PubMed

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D; Huang, Zhongyun; Hyma, Katie E; Gealy, David R; Caicedo, Ana L

    2014-11-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

  4. Rice tungro spherical virus resistance into photoperiod-insensitive japonica rice by marker-assisted selection.

    PubMed

    Shim, Junghyun; Torollo, Gideon; Angeles-Shim, Rosalyn B; Cabunagan, Rogelio C; Choi, Il-Ryong; Yeo, Un-Sang; Ha, Woon-Goo

    2015-09-01

    Rice tungro disease (RTD) is one of the destructive and prevalent diseases in the tropical region. RTD is caused by Rice tungro spherical virus (RTSV) and Rice tungro bacilliform virus. Cultivation of japonica rice (Oryza sativa L. ssp japonica) in tropical Asia has often been restricted because most japonica cultivars are sensitive to short photoperiod, which is characteristic of tropical conditions. Japonica1, a rice variety bred for tropical conditions, is photoperiod-insensitive, has a high yield potential, but is susceptible to RTD and has poor grain quality. To transfer RTD resistance into Japonica1, we made two backcrosses (BC) and 8 three-way crosses (3-WC) among Japonica1 and RTSV-resistant cultivars. Among 8,876 BC1F2 and 3-WCF2 plants, 342 were selected for photoperiod-insensitivity and good grain quality. Photoperiod-insensitive progenies were evaluated for RTSV resistance by a bioassay and marker-assisted selection (MAS), and 22 BC1F7 and 3-WCF7 lines were selected based on the results of an observational yield trial. The results demonstrated that conventional selection for photoperiod-insensitivity and MAS for RTSV resistance can greatly facilitate the development of japonica rice that is suitable for cultivation in tropical Asia. PMID:26366118

  5. Microbial dynamics and arsenic speciation in rice paddy soil under two water management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arsenic (As) undergoes several microbial transformations, including oxidation/reduction, methylation/demethylation, and volatilization in soil, which impact As bioavailability. Different water management systems for rice cultivation alter soil-redox conditions and As biogeochemistry. Soil microbial ...

  6. Barnyard grasses were processed with rice around 10000 years ago.

    PubMed

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-01-01

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process. PMID:26536839

  7. Barnyard grasses were processed with rice around 10000 years ago

    PubMed Central

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-01-01

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process. PMID:26536839

  8. Abandoned Rice Fields Make Streams Go Dry in Upland Landscapes

    NASA Astrophysics Data System (ADS)

    Jayawickreme, D.

    2015-12-01

    In South Asia, new economic realities are driving many rural rice farmers out of agriculture. With increasing neglect, abandonment, and rising conversions of centuries old rice fields into other uses, ecological and environmental consequences of these transitions are becoming progressively clear. Field observations in Sri Lanka's central highlands suggest that small shifts in rice to non-rice land uses in headwater watersheds can have a domino effect on the productivity and viability of rice fields and other ecological systems downstream by inflicting groundwater recharge reductions, lowering groundwater yields, and causing other hydrological changes. Preliminary analysis shows that although rice itself is a very water intensive crop, the presence of rain-fed upland rice-fields is hugely beneficial to the watersheds they reside. In particular, water benefits of rice appear to be derived from ponded conditions (3-5 inches of standing water) in which rice is grown, and the contribution rice fields makes to enhance water retention and storage capacity of their watersheds during the monsoon season that coincide with the cropping season. In the absence of well managed rice-fields, hilly upland landscapes produce more runoff and retain little rainwater during the wet season. Furthermore, after centuries of intensive use, much of South Asia's rice fields are nutrient poor and minimally productive without fertilizer applications and other interventions. Consequently, when abandoned, soil erosion and other impacts that affect aquatic ecosystems and watershed health also emerge. Despite these multiple concerns however, little research is currently done to better understand the environmental significance of rice cultivations that are a dominant land-use in many South Asian landscapes. The aim of this presentation is to stir interest among the scientific community to engage more broadly in rice, water, and environmental change research in the face of new economic realities in

  9. Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

    PubMed

    Maltchik, Leonardo; Rolon, Ana Silvia; Stenert, Cristina; Machado, Iberê Farina; Rocha, Odete

    2011-12-01

    Conservation of species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1) Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2) Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006). A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production. PMID:22208101

  10. Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice

    SciTech Connect

    Su, J.; Hu, C.; Yan, X.; Jin, Y.; Chen, Z.; Guan, Q.; Wang, Y.; Zhong, D.; Jansson, Georg C.; Wang, F.; Schnrer, Anna; Sun, Chuanxin

    2015-07-22

    Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7–17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25–100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades4. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement5. Despite proposed strategies to increase rice productivity and reduce methane emissions4,6, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2, conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane

  11. Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice.

    PubMed

    Su, J; Hu, C; Yan, X; Jin, Y; Chen, Z; Guan, Q; Wang, Y; Zhong, D; Jansson, C; Wang, F; Schnürer, A; Sun, C

    2015-07-30

    Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7-17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25-100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement. Despite proposed strategies to increase rice productivity and reduce methane emissions, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2 (refs 7, 8), conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased

  12. Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice

    NASA Astrophysics Data System (ADS)

    Su, J.; Hu, C.; Yan, X.; Jin, Y.; Chen, Z.; Guan, Q.; Wang, Y.; Zhong, D.; Jansson, C.; Wang, F.; Schnürer, A.; Sun, C.

    2015-07-01

    Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7-17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25-100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement. Despite proposed strategies to increase rice productivity and reduce methane emissions, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2 (refs 7, 8), conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased

  13. Optimal fertilizer N rates and yield-scaled global warming potential in drill seeded rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drill seeded rice (Oryza sativa L.) is the dominant rice cultivation practice in the USA. Although drill seeded systems can lead to significant methane and nitrous oxide emissions due to the presence of both anaerobic and aerobic soil conditions, the relationship between high-yielding management pr...

  14. Statistical inference of selection and divergence of rice blast resistance gene Pi-ta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The resistance gene Pi-ta has been effectively used to control rice blast disease worldwide. A few recent studies have described the possible evolution of Pi-ta in cultivated and weedy rice. However, evolutionary statistics used for the studies are too limited to precisely understand selection and d...

  15. Seeing red: The origin of grain pigmentation in US weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice (Oryza sativa L.) is the major weed of cultivated rice fields in the US, where it causes tens of millions of dollars in crop losses annually. This weedy crop-relative is characterized by several traits that are typical of wild Oryza species, including the anthocyanin-pigmented pericarp tha...

  16. Genetic diversity associated with conservation of endangered Dongxiang wild rice (Oryza rufipogon)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wild progenitor species (Oryza rufipogon) of Asian cultivated rice (O. sativa) is located in Dongxiang county, China where it is considered the northernmost range worldwide. Nine ex situ and three in situ populations of the Dongxiang wild rice (DXWR) and four groups of modern cultivars were geno...

  17. Comparative Transcriptional Profiling of Two Contrasting Rice Genotypes under Salinity Stress during the Vegetative Growth Stage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa), a salt-sensitive species, has considerable genetic variation for salt tolerance within the cultivated gene pool. Two indica rice genotypes, FL478, a recombinant inbred line derived from a population developed for salinity tolerance studies, and IR29, the sensitive parent of the ...

  18. The evolutionary genomics of weedy red rice in the U.S.A.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is an interfertile, weedy form of cultivated rice (Oryza sativa) that competes aggressively with the crop in the southern U.S., reducing yields and contaminating harvests. No wild Oryza species occur in North America, and the weed has been proposed to have evolved through multiple mechanis...

  19. Positional cloning of a seed dormancy QTL from weedy rice (Oryza sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed weedy rice (SS-18-2) as a genetic system to investigate mechanisms regulating natural variation in seed dormancy. This included introduction of a set of quantitative trait loci (QTL) enhancing seed dormancy into the non-dormant genetic background of cultivated rice (EM93-1) to clone and...

  20. Archaeological and genetic insights into the origins of domesticated rice

    PubMed Central

    Gross, Briana L.; Zhao, Zhijun

    2014-01-01

    Rice (Oryza sativa) is one of the most important cereal grains in the world today and serves as a staple food source for more than half of the world’s population. Research into when, where, and how rice was brought into cultivation and eventually domesticated, along with its development into a staple food source, is thus essential. These questions have been a point of nearly continuous research in both archaeology and genetics, and new information has continually come to light as theory, data acquisition, and analytical techniques have advanced over time. Here, we review the broad history of our scientific understanding of the rice domestication process from both an archaeological and genetic perspective and examine in detail the information that has come to light in both of these fields in the last 10 y. Current findings from genetics and archaeology are consistent with the domestication of O. sativa japonica in the Yangtze River valley of southern China. Interestingly, although it appears rice was cultivated in the area by as early 8000 BP, the key domestication trait of nonshattering was not fixed for another 1,000 y or perhaps longer. Rice was also cultivated in India as early as 5000 BP, but the domesticated indica subspecies currently appears to be a product of the introgression of favorable alleles from japonica. These findings are reshaping our understanding of rice domestication and also have implications for understanding the complex evolutionary process of plant domestication. PMID:24753573

  1. Starch physicochemical properties of rice accessions and their association with molecular markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The grain quality of rice has recently attracted a lot of attention around the world, including Africa. Rice germplasm in African gene banks has not been adequately characterized for its cooking and eating qualities which are mainly controlled by starch physicochemical properties. The aim of this st...

  2. Constructing an Authentic Self: The Challenges and Promise of African-Centered Pedagogy

    ERIC Educational Resources Information Center

    Merry, Michael S.; New, William

    2008-01-01

    African-centered pedagogy aims to cultivate a positive and productive culturally based identity for Black children, and African-centered schools endeavor to supply that cultural base, placing the history, culture, and life experiences of individuals of African descent at the center of everything that they do. Our study examines the historical…

  3. [Assessment of rice achievable productivity and its application in rice production management division: a case study in Fuyang County of Zhejiang Province, East China].

    PubMed

    Wu, Hao-Xiang; Jiang, Yu-Gen; Chen, Jian-Ming; Dai, Yong-Yi; He, Xu-Hua; Qiu, Xi-Ya

    2011-11-01

    Rice productivity is the key factor affecting rice production and its sustainable development. Based on the gradation of cultivated land quality at county-level, this paper evaluated the rice productivity in Fuyang County of Zhejiang Province, and, through selected sampling field investigation and according to the land productivity index of paddy field quality, a model for assessing rice achievable productivity was established, aimed to analyze the regional rice productivity and its achievable productivity. In the study area, there was a positive correlation between the land productivity index and rice yield. For single cropping rice, its achievable productivity was 1.70 x 10(5) t, being 1.6 times of its realistic productivity (1.04 x 10(5) t). In 2009, the realistic rice productivity per unit area was 7676 kg x hm(-2), and the achievable productivity was 8831 kg x hm(-2), with a production potentiality of +15%, a big potential of rice production capacity in the county. Through the analyses of rice productivity, relative superiority of rice production scale, and its growth potential index in the villages and towns, the rice production of Fuyang County was divided into three regions, i. e., key enhancement region, optimization construction region, and development protection region. PMID:22303662

  4. Seeing Red: The Origin of Grain Pigmentation in US Weedy Rice

    PubMed Central

    Gross, Briana L.; Reagon, Michael; Hsu, Shih-Chung; Caicedo, Ana L.; Jia, Yulin; Olsen, Kenneth M.

    2010-01-01

    Weedy forms of crop species infest agricultural fields worldwide and are a leading cause of crop losses, yet little is known about how these weeds evolve. Red rice (Oryza sativa), a major weed of cultivated rice fields in the US, is recognized by the dark-pigmented grain that gives it its common name. Studies using neutral molecular markers have indicated a close relationship between US red rice and domesticated rice, suggesting that the weed may have originated through reversion of domesticated rice to a feral form. We have tested this reversion hypothesis by examining molecular variation at Rc, the regulatory gene responsible for grain pigmentation differences between domesticated and wild rice. Loss-of-function mutations at Rc account for the absence of proanthocyanidin pigments in cultivated rice grains, and the major rc domestication allele has been shown to be capable of spontaneous reversion to a functional form through additional mutations at the Rc locus. Using a diverse sample of 156 weedy, domesticated, and wild Oryzas, we analyzed DNA sequence variation at Rc and its surrounding 4 Mb genomic region. We find that reversion of domestication alleles does not account for the pigmented grains of weed accessions; moreover, we find that haplotypes characterizing the weed are either absent or very rare in cultivated rice. Sequences from genomic regions flanking Rc are consistent with a genomic footprint of the rc selective sweep in cultivated rice, and are compatible with a close relationship of red rice to Asian Oryzas that have never been cultivated in the US. PMID:20584133

  5. Functional diversity of jasmonates in rice.

    PubMed

    Liu, Zheng; Zhang, Shumin; Sun, Ning; Liu, Hongyun; Zhao, Yanhong; Liang, Yuling; Zhang, Liping; Han, Yuanhuai

    2015-12-01

    Phytohormone jasmonates (JA) play essential roles in plants, such as regulating development and growth, responding to environmental changes, and resisting abiotic and biotic stresses. During signaling, JA interacts, either synergistically or antagonistically, with other hormones, such as salicylic acid (SA), gibberellin (GA), ethylene (ET), auxin, brassinosteroid (BR), and abscisic acid (ABA), to regulate gene expression in regulatory networks, conferring physiological and metabolic adjustments in plants. As an important staple crop, rice is a major nutritional source for human beings and feeds one third of the world's population. Recent years have seen significant progress in the understanding of the JA pathway in rice. In this review, we summarize the diverse functions of JA, and discuss the JA interplay with other hormones, as well as light, in this economically important crop. We believe that a better understanding of the JA pathway will lead to practical biotechnological applications in rice breeding and cultivation. PMID:26054241

  6. Rice yellow mottle virus in Madagascar and in the Zanzibar Archipelago; island systems and evolutionary time scale to study virus emergence.

    PubMed

    Rakotomalala, Mbolarinosy; Pinel-Galzi, Agnès; Mpunami, Anatolia; Randrianasolo, Albert; Ramavovololona, Perle; Rabenantoandro, Yvonne; Fargette, Denis

    2013-01-01

    Rice yellow mottle virus (RYMV), of the genus Sobemovirus, is a major threat to rice cultivation in Africa. Long range transmission of RYMV, difficult to study experimentally, is inferred from a detailed analysis of the molecular diversity of the virus in Madagascar and in the Zanzibar Archipelago (Zanzibar and Pemba Islands; Tanzania) compared with that found elsewhere in Africa. A unique successful introduction of RYMV to Madagascar, which is ca. 400 km from mainland Africa, contrasted with recurrent introductions of the virus to the Zanzibar Archipelago, ca. 40 km from the East African coast. Accordingly, RYMV dispersal over distances of hundreds of kilometers is rare whereas spread of the virus over distances of tens of kilometers is relatively frequent. The dates of introduction of RYMV to Madagascar and to Pemba Island were estimated from three sets of ORF4 sequences of virus isolates collected between 1966 and 2011. They were compared with the dates of the first field detection in Madagascar (1989) and in Pemba Island (1990). The estimates did not depend substantially on the data set used or on the evolutionary model applied and their credible intervals were narrow. The estimated dates are recent - 1978 (1969-1986) and 1985 (1977-1993) in Madagascar and in Pemba Island, respectively - compared to the early diversification of RYMV in East Africa ca. 200 years ago. They predated by 5-10 years the first field detections in these islands. The interplay between virus sources, rice cultivation and long range dispersal which led to RYMV emergence and spread is enlightened. PMID:23123216

  7. Unravelling the proteomic profile of rice meiocytes during early meiosis

    PubMed Central

    Collado-Romero, Melania; Alós, Enriqueta; Prieto, Pilar

    2014-01-01

    Transfer of genetic traits from wild or related species into cultivated rice is nowadays an important aim in rice breeding. Breeders use genetic crosses to introduce desirable genes from exotic germplasms into cultivated rice varieties. However, in many hybrids there is only a low level of pairing (if existing) and recombination at early meiosis between cultivated rice and wild relative chromosomes. With the objective of getting deeper into the knowledge of the proteins involved in early meiosis, when chromosomes associate correctly in pairs and recombine, the proteome of isolated rice meiocytes has been characterized by nLC-MS/MS at every stage of early meiosis (prophase I). Up to 1316 different proteins have been identified in rice isolated meiocytes in early meiosis, being 422 exclusively identified in early prophase I (leptotene, zygotene, or pachytene). The classification of proteins in functional groups showed that 167 were related to chromatin structure and remodeling, nucleic acid binding, cell-cycle regulation, and cytoskeleton. Moreover, the putative roles of 16 proteins which have not been previously associated to meiosis or were not identified in rice before, are also discussed namely: seven proteins involved in chromosome structure and remodeling, five regulatory proteins [such as SKP1 (OSK), a putative CDK2 like effector], a protein with RNA recognition motifs, a neddylation-related protein, and two microtubule-related proteins. Revealing the proteins involved in early meiotic processes could provide a valuable tool kit to manipulate chromosome associations during meiosis in rice breeding programs. The data have been deposited to the ProteomeXchange with the PXD001058 identifier. PMID:25104955

  8. Improving salt tolerance of lowland rice cultivar 'Rassi' through marker-aided backcross breeding in West Africa.

    PubMed

    Bimpong, Isaac Kofi; Manneh, Baboucarr; Sock, Mamadou; Diaw, Faty; Amoah, Nana Kofi Abaka; Ismail, Abdelbagi M; Gregorio, Glenn; Singh, Rakesh Kumar; Wopereis, Marco

    2016-01-01

    Salt stress affects about 25% of the 4.4 million ha of irrigated and lowland systems for rice cultivation in West Africa (WA). A major quantitative trait locus (QTLs) on chromosome 1 (Saltol) that enhances tolerance to salt stress at the vegetative stage has enabled the use of marker-assisted selection (MAS) to develop salt-tolerant rice cultivar(s) in WA. We used 3 cycles of backcrossing with selection based on DNA markers and field-testing using 'FL478' as tolerant donor and the widely grown 'Rassi' as recurrent parent. In the BC3F2 stage, salt-tolerant lines with over 80% Rassi alleles except in the region around Saltol segment were selected. 429 introgression lines (Saltol-ILs) were identified as tolerant at vegetative stage, of which 116 were field-tested for four seasons at the reproductive stage. Sixteen Saltol-ILs had less yield loss (3-26% relative to control trials), and 8 Saltol-ILs showed high yield potential under stress and non-stress conditions. The 16 Saltol-ILs had been included for further African-wide testing prior to release in 6 WA countries. MAS reduced the time for germplasm improvement from at least 7 to about 4 years. Our objective is to combine different genes/QTLs conferring tolerance to stresses under one genetic background using MAS. PMID:26566846

  9. Contact urticaria from rice.

    PubMed

    Yamakawa, Y; Ohsuna, H; Aihara, M; Tsubaki, K; Ikezawa, Z

    2001-02-01

    A 30-year-old man with atopic dermatitis had had erythema and itching of the hands after washing rice in water, though he had always eaten cooked rice without problems. Handling test with water used to wash regular rice was performed on abraded hands, and produced urticarial erythema after several minutes. Applications of water used to wash allergen-reduced rice were negative for urticarial reaction. Prick test with water used to wash regular rice was +++. However prick test reaction with water used to wash allergen-reduced rice was +. Histamine-release test of regular rice-washing water was grade 3 and that of allergen-reduced rice grade 1. In immunoblotting analysis with regular rice washing water, there were no bands with this patient. These results suggest that the allergen responsible for contact urticaria in this patient might be water-soluble, heat-unstable, and not contained in allergen-reduced rice. PMID:11205411

  10. Spirulina cultivation in China

    NASA Astrophysics Data System (ADS)

    Wu, Bo-Tang; Xiang, Wen-Zhou; Zeng, Cheng-Kui

    1998-03-01

    This paper reviews and discusses the development and many problems of Spirulina cultivation in China, points out the advantages and disadvantages of open photobioreactor system, and predicts that seawater Spirulina cultivation will be a new trend to be strengthened and emphasized due to its special physiological characteristics, easier management, lower fertilizer cost, and higher resistance to contaminants and rare pollution of chemicals.

  11. Rice ( Oryza) hemoglobins

    PubMed Central

    Arredondo-Peter, Raúl; Moran, Jose F.; Sarath, Gautam

    2014-01-01

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs. PMID:25653837

  12. Unlocking the variation hidden in rice germplasm collections with genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated Asian rice (Oryza sativa) was domesticated from O. rufipogon (O. nivara). The O. sativa subspecies indica and japonica diverged in ancient times, and based on DNA markers, further subdivided into the five major subpopulations, aus, indica, aromatic, tropical japonica and temperate japoni...

  13. Fungicide sensitivity in the wild rice pathogen Bipolaris oryzae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years the occurrence of fungal brown spot, caused by Bipolaris oryzae has increased in cultivated wild rice (Zizania palustris) paddies in spite of the use of fungicides. To implement an efficient integrated disease management system, we are exploring whether field isolates have developed ...

  14. The biogeography of viral emergence: rice yellow mottle virus as a case study.

    PubMed

    Pinel-Galzi, Agnès; Traoré, Oumar; Séré, Yacouba; Hébrard, Eugénie; Fargette, Denis

    2015-02-01

    Rice yellow mottle virus (RYMV) exemplifies the key role in plant virus emergence of the early steps of crop extension and intensification in traditional agriculture. In East Africa, RYMV emerged in the 19(th) century after rice intensification along the Indian Ocean coast, and later spread inland concomitantly with rice introduction. In West Africa, the contrasted history of rice cultivation among regions differently shaped RYMV populations. A biogeographical approach - which jointly considers the spatial distribution of the virus and its hosts over time - was applied to reach these conclusions. We linked the evolution of RYMV over the past two centuries to a geographical map of the history of rice cultivation in Africa. PMID:25544357

  15. Localization and speciation of arsenic and trace elements in rice tissues

    SciTech Connect

    Smith, Euan; Kempson, Ivan; Juhasz, Albert L.; Weber, John; Skinner, William M.; Gräfe, Markus

    2009-09-14

    The consumption of arsenic (As) contaminated rice is an important exposure route for humans in countries where rice cultivation employs As contaminated irrigation water. Arsenic toxicity and mobility are a function of its chemical-speciation. The distribution and identification of As in the rice plant are hence necessary to determine the uptake, transformation and potential risk posed by As contaminated rice. In this study we report on the distribution and chemical-speciation of As in rice (Oryza sativa Quest) by X-ray fluorescence (XRF) and X-ray absorption near edge structure (XANES) measurements of rice plants grown in As contaminated paddy water. Investigations of {mu}XRF images from rice tissues found that As was present in all rice tissues, and its presence correlated with the presence of iron at the root surface and copper in the rice leaf. X-ray absorption near edge structure analysis of rice tissues identified that inorganic As was the predominant form of As in all rice tissues studied, and that arsenite became increasingly dominant in the aerial portion of the rice plant.

  16. QTL Analysis for Resistance to Blast Disease in U.S. Weedy Rice.

    PubMed

    Liu, Yan; Qi, Xinshuai; Gealy, Dave R; Olsen, Kenneth M; Caicedo, Ana L; Jia, Yulin

    2015-07-01

    Understanding the genetic architecture of adaptation is of great importance in evolutionary biology. U.S. weedy rice is well adapted to the local conditions in U.S. rice fields. Rice blast disease is one of the most destructive diseases of cultivated rice worldwide. However, information about resistance to blast in weedy rice is limited. Here, we evaluated the disease reactions of 60 U.S. weedy rice accessions with 14 blast races, and investigated the quantitative trait loci (QTL) associated with blast resistance in two major ecotypes of U.S. weedy rice. Our results revealed that U.S. weedy rice exhibited a broad resistance spectrum. Using genotyping by sequencing, we identified 28 resistance QTL in two U.S. weedy rice ecotypes. The resistance QTL with relatively large and small effects suggest that U.S. weedy rice groups have adapted to blast disease using two methods, both major resistance (R) genes and QTL. Three genomic loci shared by some of the resistance QTL indicated that these loci may contribute to no-race-specific resistance in weedy rice. Comparing with known blast disease R genes, we found that the R genes at these resistance QTL are novel, suggesting that U.S. weedy rice is a potential source of novel blast R genes for resistant breeding. PMID:25761210

  17. Nutritional constituents and health benefits of wild rice (Zizania spp.).

    PubMed

    Surendiran, Gangadaran; Alsaif, Maha; Kapourchali, Fatemeh Ramezani; Moghadasian, Mohammed H

    2014-04-01

    Wild rice (Zizania spp.) seems to have originated in North America and then dispersed into Eastern Asia and other parts of the world. Nutritional analysis shows that wild rice is rich in minerals, vitamins, protein, starch, dietary fiber, and various antioxidant phytochemicals, while it is low in fat. Wild rice has been recognized as a whole grain by the US Food and Drug Administration; in the North American marketplace it is currently sold as and considered to be a health-promoting food. Recent scientific studies have revealed antioxidant and lipid-lowering properties of wild rice, while others have documented cardiovascular benefits associated with the long-term consumption of wild rice in experimental settings. The present review article summarizes various features of wild rice and its cultivation, including its plantation, harvest, nutritional composition, and biological properties. While evidence for the cardiovascular benefits of wild rice consumption is accumulating, additional studies are warranted to determine the clinical benefits of regular consumption of wild rice. PMID:24684371

  18. Behavior of iodine-129 in rice paddy fields

    SciTech Connect

    Uchida, Shigeo; Muramatsu, Yasuyuki

    1995-12-31

    Transfer factors of iodine from soil to rice were obtained by laboratory experiments using {sup 125}I tracer. Two typical soil types in Japan, Andosol and Gray lowland soil, were used. The transfer factor (TF) is defined as concentration of the nuclide in a plant organ at harvest divided by concentration of the nuclide in dry soil. The TFs for brown (hulled) rice were 0.006 for Andosol and 0.002 for Gray lowland soil. The TFs for different organs of rice plants decreased in the order of blade > stem > rachis > unhulled rice {much_gt} brown rice. The concentration of iodine in soil solution under flooded conditions varied with time during cultivation. The iodine concentration in rice plants seemed to be influenced by the soil solution. The effect of removal of I-129 from paddy fields by harvesting rice plants was also modeled. Even assuming continuous deposition of I-129 on the field, annual harvesting of the blades and stems of rice plants could effectively reduce the amount of the nuclide in the root zone.

  19. The Impact of Herbicide-Resistant Rice Technology on Phenotypic Diversity and Population Structure of United States Weedy Rice1[W][OPEN

    PubMed Central

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D.; Huang, Zhongyun; Hyma, Katie E.; Gealy, David R.; Caicedo, Ana L.

    2014-01-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

  20. IDENTIFICATION OF GENES INVOLVED IN COLD RESISTANCE DURING SEED GERMINATION AND POSTGERMINATION OF RICE USING COMPARATIVE PROTEOMICS AND GENOMICS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the molecular mechanisms underlying the low temperature germinability is important in expanding the niche of cereal crops. US red rice accessions provide an excellent source of new alleles for improving cultivated rice yield, quality, stress tolerance, and disease resistance. Here we p...

  1. Diazinon accumulation and dissipation in Oryza sativa L. following simulated agricultural runoff amendment in flooded rice paddies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flooded post-harvest rice paddies were examined as potential best management practices for reducing diazinon (organophosphate insecticide) concentrations in stormwater runoff. Two rice paddies were cultivated in Oryza sativa L. and amended with a 3hr, 0.1% simulated stormwater diazinon runoff event....

  2. MOLECULAR AND PATHOLOGICAL CHARACTERIZATION OF RICE SHEATH BLIGHT PATHOGEN ISOLATES FROM ARKANSAS USING RDNA-INTERNAL TRANSCRIBED SPACER SEQUENCES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice sheath blight, caused by Rhizoctonia solani Kühn (anastomosis group AG1-IA), is a serious disease worldwide. R. solani has a broad host range and no complete genetic resistance is available among cultivated rices. As first step to identify sheath blight resistance gene(s), molecular character...

  3. Alternate wetting and drying in high yielding direct-seeded rice systems accomplishes multiple environmental and agronomic objectives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) cultivation is critically important for global food security, yet it also represents a significant fraction of agricultural greenhouse gas (GHG) emissions and water resource use. Alternate wetting and drying (AWD) of rice fields has been shown to reduce both methane (CH4) emis...

  4. Alternate wetting and drying in high yielding direct-seeded rice systems accomplishes multiple environmental and agronomic objectives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice cultivation is critically important for global food security, yet it also represents a significant fraction of agricultural greenhouse gas (GHG) emissions and water resource use. Alternate wetting and drying (AWD) of rice fields has been shown to reduce both methane (CH4) emissions and water us...

  5. Microbial communities in rice rhizosphere altered by intermittent and continuous flooding in fields with long-term arsenic application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice cultivated on arsenic -contaminated soils can, under some conditions, accumulate high concentrations in the grain, particularly continuous flooding practices are used. Intermittent flooding, as opposed to continuous flooding, could be a means to reduce soluble arsenic concentrations in the rice...

  6. Morphological Study of the Relationships between Weedy Rice Accessions (Oryza sativa Complex) and Commercial Rice Varieties in Pulau Pinang Rice Granary Area

    PubMed Central

    Hussain, Zainudin PMD; Man, Azmi; Othman, Ahmad Sofiman

    2010-01-01

    Weedy rice (WR) is found in many direct-seeded rice fields. WR possesses morphological characteristics that are similar to cultivated rice varieties in the early stage of growth, making them more difficult to control than other weeds. A comparative morphological study was conducted by collecting WR accessions from four sites within the Pulau Pinang rice growing areas. The objective of the study was to characterise WR accessions of the Pulau Pinang rice granary by comparing their morphological characteristics to those of commercially grown rice in the area. Their morphometric relations were established by comparing 17 morphological characteristics of the WR accessions and the commercial varieties. A total of 36 WR morphotypes were identified from these 4 sites based on 17 characteristics, which included grain shattering habit and germination rate. The Principal Component Analysis (PCA) showed that 45.88% of the variation observed among the WR accessions and commercial varieties were within the first 3 axes. PB6, PP2 and SGA5 WR accessions had a higher number of tillers and longer panicle lengths, culm heights and leaf lengths compared to the commercial rice. The grain sizes of the commercial varieties were slightly longer, and the chlorophyll contents at 60–70 days after sowing (DAS) were higher than those of the WR accessions. Results from this study are useful for predicting potential WR accession growth, which might improve WR management and agriculture practices that control WR in the future. PMID:24575197

  7. Cultivation of parasites

    PubMed Central

    Ahmed, Nishat Hussain

    2014-01-01

    Parasite cultivation techniques constitute a substantial segment of present-day study of parasites, especially of protozoa. Success in establishing in vitro and in vivo culture of parasites not only allows their physiology, behavior and metabolism to be studied dynamically, but also allows the nature of the antigenic molecules in the excretory and secretory products to be vigorously pursued and analyzed. The complex life-cycles of various parasites having different stages and host species requirements, particularly in the case of parasitic helminths, often make parasite cultivation an uphill assignment. Culturing of parasites depends on the combined expertise of all types of microbiological cultures. Different parasites require different cultivation conditions such as nutrients, temperature and even incubation conditions. Cultivation is an important method for diagnosis of many clinically important parasites, for example, Entamoeba histolytica, Trichomonas vaginalis, Leishmania spp., Strongyloides stercoralis and free-living amoebae. Many commercial systems like InPouch TV for T. vaginalis, microaerophilous stationary phase culture for Babesia bovis and Harada-Mori culture technique for larval-stage nematodes have been developed for the rapid diagnosis of the parasitic infections. Cultivation also has immense utility in the production of vaccines, testing vaccine efficacy, and antigen - production for obtaining serological reagents, detection of drug-resistance, screening of potential therapeutic agents and conducting epidemiological studies. Though in vitro cultivation techniques are used more often compared with in vivo techniques, the in vivo techniques are sometimes used for diagnosing some parasitic infections such as trypanosomiasis and toxoplasmosis. Parasite cultivation continues to be a challenging diagnostic option. This review provides an overview of intricacies of parasitic culture and update on popular methods used for cultivating parasites. PMID

  8. Sequential Crop Cultivation Experiment using CEEF for Human Habitation

    NASA Astrophysics Data System (ADS)

    Tako, Y.; Arai, R.; Nitta, K.; Shinohara, M.

    The Closed Ecology Experiment Facilities (CEEF) can be used as a test bed for Controlled Ecological Life Support Systems (CELSS), because technologies developed for the CEEF system facilitate self-sufficient material circulation. In the experiment conducted from August to December of 2001, rice and soybeans were cultivated sequentially in two chambers and a chamber, each having a cultivation bed area of 30 m 2 and floor area of 43 m 2, inside the Plantation Module with artificial lighting of the CEEF. Stable transplant or seeding and harvest of each crop were maintained during 28 days, after a 110-days preparatory cultivation. Flows of gas and liquid materials to and from the crops were analyzed during the stable cultivation period. Almost all equipments of the Gas Processing Subsystem of the Closed Plantation Experiment Facilities (CPEF) in the CEEF were operated during the period. Stable operation of the subsystem was confirmed during the period. Daily averages of carbohydrate, lipid, and protein contained in edible biomass from harvested rice and soybeans for the 28-days were 2.1, 1.2, and 2.2 of the necessary amount of each for a standard human activity. Stable uptake of CO2 by each crop was confirmed during the 28 -days. Amounts of CO2 taken up by each crop were consistent with produced biomass of both crops. Exchange ratios of CO2 and O2 were also consistent with nutritional compositions of both crops biomass.

  9. Y chromosome lineages in men of west African descent.

    PubMed

    Torres, Jada Benn; Doura, Menahem B; Keita, Shomarka O Y; Kittles, Rick A

    2012-01-01

    The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called "Grain Coast" of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30-40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations. PMID:22295064

  10. Y Chromosome Lineages in Men of West African Descent

    PubMed Central

    Keita, Shomarka O. Y.; Kittles, Rick A.

    2012-01-01

    The early African experience in the Americas is marked by the transatlantic slave trade from ∼1619 to 1850 and the rise of the plantation system. The origins of enslaved Africans were largely dependent on European preferences as well as the availability of potential laborers within Africa. Rice production was a key industry of many colonial South Carolina low country plantations. Accordingly, rice plantations owners within South Carolina often requested enslaved Africans from the so-called “Grain Coast” of western Africa (Senegal to Sierra Leone). Studies on the African origins of the enslaved within other regions of the Americas have been limited. To address the issue of origins of people of African descent within the Americas and understand more about the genetic heterogeneity present within Africa and the African Diaspora, we typed Y chromosome specific markers in 1,319 men consisting of 508 west and central Africans (from 12 populations), 188 Caribbeans (from 2 islands), 532 African Americans (AAs from Washington, DC and Columbia, SC), and 91 European Americans. Principal component and admixture analyses provide support for significant Grain Coast ancestry among African American men in South Carolina. AA men from DC and the Caribbean showed a closer affinity to populations from the Bight of Biafra. Furthermore, 30–40% of the paternal lineages in African descent populations in the Americas are of European ancestry. Diverse west African ancestries and sex-biased gene flow from EAs has contributed greatly to the genetic heterogeneity of African populations throughout the Americas and has significant implications for gene mapping efforts in these populations. PMID:22295064

  11. Spectral and spatial characterization of rice field mosquito habitat

    NASA Technical Reports Server (NTRS)

    Wood, Byron L.; Beck, Louisa R.; Washino, Robert K.; Palchick, Susan M.; Sebesta, Paul D.

    1991-01-01

    Irrigated rice provides an ideal breeding habitat for Anopheles free-borni, the western malaria mosquito, throughout California. In a 1985 study, it was determined that early-season rice canopy development, as monitored using remotely sensed data, could be used to distinguish between high and low mosquito producing rice fields. This distinction could be made over two months prior to peak mosquito production. It was found that high-producing fields were located in an area characterized by a diversity of land use, including livestock pastures, whereas the low-producing fields were in an area devoted almost exclusively to the cultivation of rice. The ability to distinguish between high and low mosquito producing fields prior to peak mosquito production is important in terms of mosquito habitat surveillance and control.

  12. A Methodological Investigation of Cultivation.

    ERIC Educational Resources Information Center

    Rubin, Alan M.; And Others

    Cultivation theory states that television engenders negative emotions in heavy viewers. Noting that cultivation methodology contains an apparent response bias, a study examined relationships between television exposure and positive restatements of cultivation concepts and tested a more instrumental media uses and effects model. Cultivation was…

  13. Mapping paddy rice distribution using multi-temporal Landsat imagery in the Sanjiang Plain, northeast China

    NASA Astrophysics Data System (ADS)

    Jin, Cui; Xiao, Xiangming; Dong, Jinwei; Qin, Yuanwei; Wang, Zongming

    2016-03-01

    Information of paddy rice distribution is essential for food production and methane emission calculation. Phenology-based algorithms have been utilized in the mapping of paddy rice fields by identifying the unique flooding and seedling transplanting phases using multi-temporal moderate resolution (500 m to 1 km) images. In this study, we developed simple algorithms to identify paddy rice at a fine resolution at the regional scale using multi-temporal Landsat imagery. Sixteen Landsat images from 2010-2012 were used to generate the 30 m paddy rice map in the Sanjiang Plain, northeast China—one of the major paddy rice cultivation regions in China. Three vegetation indices, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI), were used to identify rice fields during the flooding/transplanting and ripening phases. The user and producer accuracies of paddy rice on the resultant Landsat-based paddy rice map were 90% and 94%, respectively. The Landsat-based paddy rice map was an improvement over the paddy rice layer on the National Land Cover Dataset, which was generated through visual interpretation and digitalization on the fine-resolution images. The agricultural census data substantially underreported paddy rice area, raising serious concern about its use for studies on food security.

  14. Rice production with minimal irrigation and no nitrogen fertilizer by intensive use of treated municipal wastewater.

    PubMed

    Muramatsu, Ayumi; Watanabe, Toru; Sasaki, Atsushi; Ito, Hiroaki; Kajihara, Akihiko

    2014-01-01

    We designed a new cultivation system of rice with circulated irrigation to remove nitrogen from treated municipal wastewater effectively and assessed the possibility of nitrogen removal in the new system without any adverse effects on rice production through bench-scale experiments through two seasons. Overgrowth of the rice plant, which can lead to lodging and tasteless rice, was found in the first season probably because nitrogen supply based on standard practice in normal paddy fields was too much in the closed irrigation system. In the second season, therefore, the amount of treated wastewater initially applied to the system was reduced but this resulted in a considerably decreased yield. On the other hand, the taste of the rice was significantly improved. The two-season experiments revealed that the new system enabled rice production with minimal irrigation (approximately 50% on the yield base compared to normal paddy fields) and no nitrogen fertilizer. The system also achieved >95% removal of nitrogen from the treated wastewater used for circulated irrigation. The accumulation of harmful metals in the rice was not observed after one season of cultivation in the new system. The accumulation after cultivation using the same soil repeatedly for a longer time should be examined by further studies. PMID:25098882

  15. Rice Production and Marketing.

    ERIC Educational Resources Information Center

    Briers, Gary; Lee, Jasper S.

    This guide contains lesson plans for use in secondary programs of agricultural education in geographical areas in which rice is produced. Six units and 13 problem areas are organized into teaching plans that cover the broad nature of rice production. The six units are: (1) determining the importance and history of rice production; (2) determining…

  16. CFD Analysis of Bubbling Fluidized Bed Using Rice Husk

    NASA Astrophysics Data System (ADS)

    Singh, Ravi Inder; Mohapatra, S. K.; Gangacharyulu, D.

    Rice is Cultivated in all the main regions of world. The worldwide annual rice production could be 666million tons (www.monstersandcritics.com,2008) for year 2008. The annual production of rice husk is 133.2 million tons considering rice husk being 20% of total paddy production. The average annual energy potential is 1.998 *1012 MJ of rice husk considering 15MJ/kg of rice husk. India has vast resource of rice husk; a renewable source of fuel, which if used effectively would reduce the rate of depletion of fossil energy resources. As a result a new thrust on research and development in boilers bases on rice husk is given to commercialize the concept. CFD is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. High quality Computational Fluid dynamics (CFD) is an effective engineering tool for Power Engineering Industry. It can determine detailed flow distributions, temperatures, and pollutant concentrations with excellent accuracy, and without excessive effort by the software user. In the other words it is the science of predicting fluid flow, heat and mass transfer, chemical reactions and related phenomena; and an innovate strategy to conform to regulations and yet stay ahead in today's competitive power market. This paper is divided into two parts; in first part review of CFD applied to the various types of boilers based on biomass fuels/alternative fuels is presented. In second part CFD analysis of fluidized bed boilers based on rice husk considering the rice husk based furnace has been discussed. The eulerian multiphase model has used for fluidized bed. Fluidized bed has been modeled using Fluent 6.2 commercial code. The effect of numerical influence of bed superheater tubes has also been discussed.

  17. Suppression of Magnaporthe oryzae and interaction between Bacillus subtilis and rice plants in the control of rice blast.

    PubMed

    Sha, Yuexia; Wang, Qi; Li, Yan

    2016-01-01

    Magnaporthe oryzae, the causative pathogen of rice blast, has caused extensive losses to rice cultivation worldwide. Strains of the bacterium Bacillus subtilis have been used as biocontrol agents against rice blast. However, little has been reported about the interaction between B. subtilis and the rice plant and its mechanism of action. Here, the colonization process and induced disease resistance by B. subtilis SYX04 and SYX20 in rice plants was examined. Strains of B. subtilis labeled with green fluorescent protein reached population of more than 5 × 10(6) CFU/g after 20 days on mature rice leaves and were detected after 3 days on newly grown leaves. Results showed that SYX04 and SYX20 not only inhibited spore germination, germ tube length, and appressorial formation but also caused a series of alterations in the structures of hyphae and conidia. The cell walls and membrane structures of the fungus showed ultrastructural abnormalities, which became severely degraded as observed through scanning electron microscopy and transmission electron microscopy. The mixture of both B. subtilis and M. oryzae resulted in enhanced activity of peroxidase, and polyphenol oxidase while there was significantly more superoxide dismutase activity in plants that had been sprayed with B. subtilis alone. The present study suggests that colonized SYX04 and SYX20 strains protected rice plants and exhibited antifungal activity and induced systemic resistance, thus indicating their potential biological control agents. PMID:27536521

  18. Mapping rice areas of South Asia using MODIS multitemporal data

    USGS Publications Warehouse

    Gumma, M.K.; Nelson, A.; Thenkabail, P.S.; Singh, A.N.

    2011-01-01

    Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives on less than $2.00 a day. The population of the region is growing faster than its ability to produce rice. Thus, accurate and timely assessment of where and how rice is cultivated is important to craft food security and poverty alleviation strategies. We used a time series of eight-day, 500-m spatial resolution composite images from the MODIS sensor to produce rice maps and rice characteristics (e.g., intensity of cropping, cropping calendar) taking data for the years 2000 to 2001 and by adopting a suite of methods that include spectral matching techniques, decision trees, and ideal temporal profile data banks to rapidly identify and classify rice areas over large spatial extents. These methods are used in conjunction with ancillary spatial data sets (e.g., elevation, precipitation), national statistics, and maps, and a large volume of field-plot data. The resulting rice maps and statistics are compared against a subset of independent field-plot points and the best available subnational statistics on rice areas for the main crop growing season (kharif season). A fuzzy classification accuracy assessment for the 2000 to 2001 rice-map product, based on field-plot data, demonstrated accuracies from 67% to 100% for individual rice classes, with an overall accuracy of 80% for all classes. Most of the mixing was within rice classes. The derived physical rice area was highly correlated with the subnational statistics with R2 values of 97% at the district level and 99% at the state level for 2000 to 2001. These results suggest that the methods, approaches, algorithms, and data sets we used are ideal for rapid, accurate, and large-scale mapping of paddy rice as well as for generating

  19. Mapping rice areas of South Asia using MODIS multitemporal data

    NASA Astrophysics Data System (ADS)

    Gumma, Murali Krishna; Nelson, Andrew; Thenkabail, Prasad S.; Singh, Amrendra N.

    2011-01-01

    Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives on less than $2.00 a day. The population of the region is growing faster than its ability to produce rice. Thus, accurate and timely assessment of where and how rice is cultivated is important to craft food security and poverty alleviation strategies. We used a time series of eight-day, 500-m spatial resolution composite images from the MODIS sensor to produce rice maps and rice characteristics (e.g., intensity of cropping, cropping calendar) taking data for the years 2000 to 2001 and by adopting a suite of methods that include spectral matching techniques, decision trees, and ideal temporal profile data banks to rapidly identify and classify rice areas over large spatial extents. These methods are used in conjunction with ancillary spatial data sets (e.g., elevation, precipitation), national statistics, and maps, and a large volume of field-plot data. The resulting rice maps and statistics are compared against a subset of independent field-plot points and the best available subnational statistics on rice areas for the main crop growing season (kharif season). A fuzzy classification accuracy assessment for the 2000 to 2001 rice-map product, based on field-plot data, demonstrated accuracies from 67% to 100% for individual rice classes, with an overall accuracy of 80% for all classes. Most of the mixing was within rice classes. The derived physical rice area was highly correlated with the subnational statistics with R2 values of 97% at the district level and 99% at the state level for 2000 to 2001. These results suggest that the methods, approaches, algorithms, and data sets we used are ideal for rapid, accurate, and large-scale mapping of paddy rice as well as for generating

  20. Increased greenhouse-gas intensity of rice production under future atmospheric conditions

    NASA Astrophysics Data System (ADS)

    van Groenigen, Kees Jan; van Kessel, Chris; Hungate, Bruce A.

    2013-03-01

    Increased atmospheric CO2 and rising temperatures are expected to affect rice yields and greenhouse-gas (GHG) emissions from rice paddies. This is important, because rice cultivation is one of the largest human-induced sources of the potent GHG methane (CH4) and rice is the world's second-most produced staple crop. The need for meeting a growing global food demand argues for assessing GHG emissions from croplands on the basis of yield rather than land area, such that efforts to reduce GHG emissions take into consideration the consequences for food production. However, it is unclear whether or how the GHG intensity (that is, yield-scaled GHG emissions) of cropping systems will be affected by future atmospheric conditions. Here we show, using meta-analysis, that increased atmospheric CO2 (ranging from 550 to 743ppmV) and warming (ranging from +0.8°C to +6°C) both increase the GHG intensity of rice cultivation. Increased atmospheric CO2 increased GHG intensity by 31.4%, because CH4 emissions are stimulated more than rice yields. Warming increased GHG intensity by 11.8% per 1°C, largely owing to a decrease in yield. This analysis suggests that rising CO2 and warming will approximately double the GHG intensity of rice production by the end of the twenty-first century, stressing the need for management practices that optimize rice production while reducing its GHG intensity as the climate continues to change.

  1. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  2. Novel Phr1 mutations and the evolution of phenol reaction variation in US weedy rice (Oryza sativa)

    PubMed Central

    Gross, Briana L.; Skare, Karl J.; Olsen, Kenneth M.

    2010-01-01

    Summary Red rice, a major agricultural weed, is phenotypically diverse and possesses traits that are similar to both wild and cultivated rice. The genetic resources available for rice make it possible to examine the molecular basis and evolution of traits characterizing this weed. Here, we assess the phenol reaction – a classical trait for distinguishing among cultivated rice varieties – in red rice at the phenotypic and molecular levels.We phenotyped more than 100 US weed samples for the phenol reaction and sequenced the underlying Phr1 locus in a subset of samples. Data were analyzed in combination with previously published Phr1 data for cultivated rice.Most weed accessions (96.3%) are positive for the phenol reaction, and samples with a negative response carry loss-of-function alleles that are rare or heretofore undocumented. One such allele may have evolved through mutational convergence of a 1-bp frameshift insertion. Haplotype sharing between red rice and US cultivars suggests occasional crop–weed hybridization.Our discovery of previously undocumented nonfunctional phr1 alleles suggests that there are likely to be other loss-of-function mutations segregating in Oryza sativa around the world. Red rice may provide a useful study system for understanding the adaptive significance of Phr1 variation in agricultural settings. PMID:19674331

  3. Relationships among bulk soil physicochemical, biochemical, and microbiological parameters in an organic alfalfa-rice rotation system.

    PubMed

    Lopes, Ana R; Bello, Diana; Prieto-Fernández, Ángeles; Trasar-Cepeda, Carmen; Manaia, Célia M; Nunes, Olga C

    2015-08-01

    The microbial communities of bulk soil of rice paddy fields under an ancient organic agriculture regimen, consisting on an alfalfa-rice rotation system, were characterized. The drained soil of two adjacent paddies at different stages of the rotation was compared before rice seeding and after harvesting. The relationships among the soil microbial, physicochemical, and biochemical parameters were investigated using multivariate analyses. In the first year of rice cropping, aerobic cultivable heterotrophic populations correlated with lineages of presumably aerobic bacteria (e.g., Sphingobacteriales, Sphingomonadales). In the second year of rice cropping, the total C content correlated with presumable anaerobic bacteria (e.g., Anaerolineae). Independently of the year of rice cropping, before rice seeding, proteolytic activity correlated positively with the cultivable aerobic heterotrophic and ammonifier populations, the soil catabolic profile and with presumable aerobes (e.g., Sphingobacteriales, Rhizobiales) and anaerobes (e.g., Bacteroidales, Anaerolineae). After harvesting, strongest correlations were observed between cultivable diazotrophic populations and bacterial groups described as comprising N2 fixing members (e.g., Chloroflexi-Ellin6529, Betaproteobacteria, Alphaproteobacteria). It was demonstrated that chemical parameters and microbial functions were correlated with variations on the total bacterial community composition and structure occurring during rice cropping. A better understanding of these correlations and of their implications on soil productivity may be valid contributors for sustainable agriculture practices, based on ancient processes. PMID:25850741

  4. Title: Rice Crop Monitoring by Fusing Microwave and Optical Satellite Data

    NASA Astrophysics Data System (ADS)

    Oyoshi, K.; Takeuchi, W.; LE Toan, T.; Sobue, S.

    2015-12-01

    Rapid population and economic growth, and the increase in extreme weather events, are destabilizing global food security. In Asia, rice is a staple cereal crop, and the continent accounts for about 90% of global rice production and consumption. The Group on Earth Observations (GEO) Global Agricultural Monitoring (GLAM) was launched in 2011 to utilize remote sensing tools to enhance crop production projections in order to promote food security and foster sustainable economic growth. Asia---‒Rice Crop Estimation & Monitoring (Asia---‒RiCE) is a component of GEOGLAM, and aims to use remote sensing tools to develop rice---‒related information such as maps of paddy fields, rice growing conditions, yield, and production. However, in some regions in Southeast Asia, rice is planted and harvested more than twice a year, and the crop calendar is quite complicated. In addition, rice is mainly cultivated in the rainy season, and the high density of cloud cover during that season limits the observations that can be made from space using only optical sensors. In contrast, Synthetic Aperture Radar (SAR) is a robust tool because it penetrates cloud cover; however, the revisit frequency of a single SAR satellite is limited, making it difficult to capture the complicated rice crop calendar in Asia. In this research, time---‒series SAR data were fused with optical data to monitor rice crops in Southeast Asia with complicated crop calendars. In addition, a microwave radiometer that also penetrates clouds and has a high revisit frequency but a coarse spatial resolution (greater than several kilometers), was used. The integrated use of a large variety of satellite data enables us to periodically monitor surface conditions such as water inundation, transplanting, and rice crop growth and harvesting, which in turn enables us to examine rice planted areas, rice crop calendars, and rice growing conditions in order to estimate rice production.

  5. Modelling pollen-mediated gene flow in rice: risk assessment and management of transgene escape.

    PubMed

    Rong, Jun; Song, Zhiping; de Jong, Tom J; Zhang, Xinsheng; Sun, Shuguang; Xu, Xian; Xia, Hui; Liu, Bo; Lu, Bao-Rong

    2010-05-01

    Fast development and commercialization of genetically modified plants have aroused concerns of transgene escape and its environmental consequences. A model that can effectively predict pollen-mediated gene flow (PMGF) is essential for assessing and managing risks from transgene escape. A pollen-trap method was used to measure the wind-borne pollen dispersal in cultivated rice and common wild rice, and effects of relative humidity, temperature and wind speed on pollen dispersal were estimated. A PMGF model was constructed based on the pollen dispersal pattern in rice, taking outcrossing rates of recipients and cross-compatibility between rice and its wild relatives into consideration. Published rice gene flow data were used to validate the model. Pollen density decreased in a simple exponential pattern with distances to the rice field. High relative humidity reduced pollen dispersal distances. Model simulation showed an increased PMGF frequency with the increase of pollen source size (the area of a rice field), but this effect levelled off with a large pollen-source size. Cross-compatibility is essential when modelling PMGF from rice to its wild relatives. The model fits the data well, including PMGF from rice to its wild relatives. Therefore, it can be used to predict PMGF in rice under diverse conditions (e.g. different outcrossing rates and cross-compatibilities), facilitating the determination of isolation distances to minimize transgene escape. The PMGF model may be extended to other wind-pollinated plant species such as wheat and barley. PMID:20132516

  6. Using artificial neural network and satellite data to predict rice yield in Bangladesh

    NASA Astrophysics Data System (ADS)

    Akhand, Kawsar; Nizamuddin, Mohammad; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

    2015-09-01

    Rice production in Bangladesh is a crucial part of the national economy and providing about 70 percent of an average citizen's total calorie intake. The demand for rice is constantly rising as the new populations are added in every year in Bangladesh. Due to the increase in population, the cultivation land decreases. In addition, Bangladesh is faced with production constraints such as drought, flooding, salinity, lack of irrigation facilities and lack of modern technology. To maintain self sufficiency in rice, Bangladesh will have to continue to expand rice production by increasing yield at a rate that is at least equal to the population growth until the demand of rice has stabilized. Accurate rice yield prediction is one of the most important challenges in managing supply and demand of rice as well as decision making processes. Artificial Neural Network (ANN) is used to construct a model to predict Aus rice yield in Bangladesh. Advanced Very High Resolution Radiometer (AVHRR)-based remote sensing satellite data vegetation health (VH) indices (Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) are used as input variables and official statistics of Aus rice yield is used as target variable for ANN prediction model. The result obtained with ANN method is encouraging and the error of prediction is less than 10%. Therefore, prediction can play an important role in planning and storing of sufficient rice to face in any future uncertainty.

  7. Extraction of light filth from rice flours, extruded rice products, and rice paper: collaborative study.

    PubMed

    Dent, R G

    1982-09-01

    Two new methods were developed for the extraction of rodent hairs and insect fragments from rice products: one for rice flour and one for extruded rice products and rice paper. A 100 g sample of rice flour was extracted with mineral oil-40% isopropanol, followed by a water phase as needed for additional cycles. For extruded rice products and rice paper, a 225 g sample of each was initially extracted as above, followed by a single extraction with mineral oil-20% isopropanol. Both methods used an acid hydrolysis pretreatment followed by wet sieving and a percolator extraction. Average rodent hair recoveries were 77.8% for rice flour and 82.2% for extruded rice products and rice paper. Average insect fragment recoveries were 89.6% for rice flour and 91.9% for extruded rice products and rice paper. Both methods were adopted official first action. PMID:7130079

  8. Cultivating Leaders from Within

    ERIC Educational Resources Information Center

    Burdette, Maggie; Schertzer, Kristen

    2005-01-01

    A major problem faced by school districts in the US is the paucity of applicants for the posts of school principals. A solution adopted by The Capistrano Unified School District (CUSD) in Orange County California was the cultivation of good leaders from within the district through the Teaching Assistant Principal (TAP) program.

  9. The Cultivated Classroom.

    ERIC Educational Resources Information Center

    Schilder, Rosalind

    1983-01-01

    Teachers who follow this monthly schedule for starting and cultivating plants in their classrooms can look forward to blooms and greenery throughout the year. Advice on choosing plants, making cuttings, forcing bulbs, rooting sweet potatoes and pineapples, and holding a Mother's Day plant sale is included. (PP)

  10. Climatological data for the rice-growing areas along the North Coast of Puerto Rico

    USGS Publications Warehouse

    Roman-Mas, Angel; Green, Bruce

    1987-01-01

    Rainfall, temperature, wind velocity and pan evaporation data were collected from May 1983 to September 1985, in the rice growing areas of Vega Baja, Manati, and Arecibo in northern Puerto Rico. Daily values and statistics including mean, standard deviation, extremes, and totals for each month of record were compiled. Descriptions of equipment installation and operation, data processing, and significance of climatological data for rice cultivation are presented. (Author 's abstract)

  11. Cooked rice texture and rice flour pasting properties; impacted by rice temperature during milling.

    PubMed

    Saleh, Mohammed; Meullenet, Jean-Francois

    2015-03-01

    Rice milling plays a key factor in determining rice quality and value. Therefore accurate quality assessments are critical to the rice industry. This study was undertaken to assess the effect of exposing rice to elevated temperatures during milling, on cooked rice texture and rice flour pasting properties. Two long (Cybonnett and Francis) and one medium (Jupiter) rice (oryzae sativa L.) cultivars were milled using McGill laboratory mill for 30 and 40 s after warmed up the mill before milling. Four different milling temperatures per milling duration were achieved. Cooked rice texture properties were assessed using a uniaxial compression test and rice flour pasting properties measured using a TA-2000 rheometer. Results of this study showed that exposure of rice to high temperatures during milling significantly decreased cooked rice firmness. An increase in milled rice temperature after milling from 10.0 to 13.3 °C resulted in a 5.4 and 8.1 N decrease in cooked rice firmness. Although not always significant, the increase in milled rice temperature during milling resulted in an increase in cooked rice stickiness. The increase in milling temperature also showed significant increase in rice flour pasting properties. Changes in rice functional characteristics were attributed to the changes occurring to rice chemical constituents due to temperature exposure as indicated by the increase in rice protein hydrophobicity. Proteins are known to affect rice starch water holding capacity and other starch gelatinization properties. PMID:25745230

  12. [Comprehensive evaluation of improving effects of different organic wastes on a newly reclaimed cultivated land].

    PubMed

    Xu, Qiu-tong; Kong, Zhang-liang; Zhang, Ming-kui

    2016-02-01

    There are many problems such as low soil organic matter, available nutrients and microbial activity, compaction, and poor tillage properties for a newly reclaimed cultivated land, and the establishment of a fast, effective measure for improving soil fertility quality is of importance to enhance the quality and production performance of the newly cultivated land. A field experiment was carried out to observe the effect of organic wastes on soil fertility of a newly reclaimed cultivated land, and compared the differences of different types of urban organic wastes. The field experiment included nine treatments, i.e., pig manure, chicken manure, rice straw, vegetable harvest residue, urban sludge, biogas residue, manure+rice straw compost, garbage compost and control without organic fertilizer at annual application rate of 30 t . hm-2, and ran for three consecutive years. The results showed that the application of each type of the eight organic wastes had obvious effects on improving soil fertility. Among them, pig manure, chicken manure, pig manure+rice straw compost, rice straw and biogas residue were the most effective to enhance the carbon pool management index of soil. The addition of pig manure+rice straw compost and biogas residue had the best effect on increasing the soil water stable aggregates and decreasing soil bulk density. Sewage sludge, pig manure+rice straw compost and garbage compost could enhance soil water holding capacity. Pig manure, chicken manure and pig manure+rice straw compost had most obvious effect on increasing soil available nutrients. All kinds of organic wastes increased the number of soil microorganisms and the activity of enzymes. There were some risk of soil heavy metals pollution.for the long-term application of sludge, garbage compost and manure. However, the impact of short-term application of the wastes on soil environmental quality was not obvious. Overall, effects of organic wastes on soil fertility decreased in the order of pig

  13. A natural mutation in rc reverts white-rice-pericarp to red and results in a new, dominant, wild-type allele: Rc-g

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rc locus regulates pigmentation of the rice bran layer, and selection for the rc allele (white pericarp) occurred during domestication of the crop. White bran is now ubiquitous among cultivated varieties throughout rice growing regions of the world. We identified a new allele that arose by nat...

  14. Genome of Pseudomonas sp. FeS53a, a Putative Plant Growth-Promoting Bacterium Associated with Rice Grown in Iron-Stressed Soils.

    PubMed

    de Souza, Rocheli; Sant'Anna, Fernando Hayashi; Ambrosini, Adriana; Tadra-Sfeir, Michele; Faoro, Helisson; Pedrosa, Fabio Oliveira; Souza, Emanuel Maltempi; Passaglia, Luciane M P

    2015-01-01

    Pseudomonas sp. FeS53a was isolated from the roots of rice plants cultivated in one area with a well-established history of iron toxicity. The FeS53a genome sequence provides the genetic basis for understanding its lifestyle and survival in association with rice in conditions of iron toxicity. PMID:25838496

  15. Genome of Pseudomonas sp. FeS53a, a Putative Plant Growth-Promoting Bacterium Associated with Rice Grown in Iron-Stressed Soils

    PubMed Central

    de Souza, Rocheli; Sant’Anna, Fernando Hayashi; Ambrosini, Adriana; Tadra-Sfeir, Michele; Faoro, Helisson; Pedrosa, Fabio Oliveira; Souza, Emanuel Maltempi

    2015-01-01

    Pseudomonas sp. FeS53a was isolated from the roots of rice plants cultivated in one area with a well-established history of iron toxicity. The FeS53a genome sequence provides the genetic basis for understanding its lifestyle and survival in association with rice in conditions of iron toxicity. PMID:25838496

  16. A genomic perspective on the important genetic mechanisms of upland adaptation of rice

    PubMed Central

    2014-01-01

    Background Cultivated rice consists of two important ecotypes, upland and irrigated, that have respectively adapted to either dry land or irrigated cultivation. Upland rice, widely adopted in rainfed upland areas in virtue of its little water requirement, contains abundant untapped genetic resources, such as genes for drought adaptation. With water shortage exacerbated and population expanding, the need for breeding crop varieties with drought adaptation becomes more and more urgent. However, a previous oversight in upland rice research reveals little information regarding its genetic mechanisms for upland adaption, greatly hindering progress in harnessing its genetic resources for breeding and cultivation. Results In this study, we selected 84 upland and 82 irrigated accessions from all over the world, phenotyped them under both irrigated and dry land environments, and investigated the phylogenetic relations and population structure of the upland ecotype using whole genome variation data. Further comparative analysis yields a list of differentiated genes that may account for the phenotypic and physiological differences between upland and irrigated rice. Conclusions This study represents the first genomic investigation in a large sample of upland rice, providing valuable gene list for understanding upland rice adaptation, especially drought-related adaptation, and its subsequent utilization in modern agriculture. PMID:24920279

  17. [Dendrobium officinale stereoscopic cultivation method].

    PubMed

    Si, Jin-Ping; Dong, Hong-Xiu; Liao, Xin-Yan; Zhu, Yu-Qiu; Li, Hui

    2014-12-01

    The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D. officinale were studied by operating field experiment. The content of polysaccharide and extractum were determined by using phenol-sulfuric acid method and 2010 edition of "Chinese Pharmacopoeia" Appendix X A. The results showed that the land utilization of stereoscopic cultivated D. officinale increased 2.74 times, the stems, leaves and their total fresh or dry weight in unit area of stereoscopic cultivated D. officinale were all heavier than those of the ground cultivated ones. There was no significant difference in polysaccharide content between stereoscopic cultivation and ground cultivation. But the extractum content and total content of polysaccharide and extractum were significantly higher than those of the ground cultivated ones. In additional, the polysaccharide content and total content of polysaccharide and extractum from the top two levels of stereoscopic culture matrix were significantly higher than that of the ones from the other levels and ground cultivation. Steroscopic cultivation can effectively improves the utilization of space and yield, while the total content of polysaccharides and extractum were significantly higher than that of the ground cultivated ones. The significant difference in Dendrobium polysaccharides among the plants from different height of stereo- scopic culture matrix may be associated with light factor. PMID:25911804

  18. Microbial Community Structure in the Rhizosphere of Rice Plants

    PubMed Central

    Breidenbach, Björn; Pump, Judith; Dumont, Marc G.

    2016-01-01

    The microbial community in the rhizosphere environment is critical for the health of land plants and the processing of soil organic matter. The objective of this study was to determine the extent to which rice plants shape the microbial community in rice field soil over the course of a growing season. Rice (Oryza sativa) was cultivated under greenhouse conditions in rice field soil from Vercelli, Italy and the microbial community in the rhizosphere of planted soil microcosms was characterized at four plant growth stages using quantitative PCR and 16S rRNA gene pyrotag analysis and compared to that of unplanted bulk soil. The abundances of 16S rRNA genes in the rice rhizosphere were on average twice that of unplanted bulk soil, indicating a stimulation of microbial growth in the rhizosphere. Soil environment type (i.e., rhizosphere versus bulk soil) had a greater effect on the community structure than did time (e.g., plant growth stage). Numerous phyla were affected by the presence of rice plants, but the strongest effects were observed for Gemmatimonadetes, Proteobacteria, and Verrucomicrobia. With respect to functional groups of microorganisms, potential iron reducers (e.g., Geobacter, Anaeromyxobacter) and fermenters (e.g., Clostridiaceae, Opitutaceae) were notably enriched in the rhizosphere environment. A Herbaspirillum species was always more abundant in the rhizosphere than bulk soil and was enriched in the rhizosphere during the early stage of plant growth. PMID:26793175

  19. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  20. Energy from rice residues

    SciTech Connect

    Mahin, D.B.

    1990-03-01

    Developing countries produce millions of tons of rice husks and straw as a byproduct of harvesting rice. Although some of these rice residues are used for fuel or other purposes, most are burned for disposal or just dumped. However, since the mid- 1980's, industrial plants for rice residue utilization have been installed in several countries and are planned in a number of others. The report provides information on systems to produce energy from rice residues that are commercially available in the United States, Europe, and various developing countries, with an emphasis on those currently used or sold on an international level. Specifically reviewed are the use of rice husks to produce: (1) industrial process heat either directly from furnaces or by generating low pressure steam in boilers; (2) mechanical and electrical power for rice milling via steam engine systems, steam turbine/generator systems, and gasifier/engine systems; and (3) electric power for the grid. The outlook for producing energy from rice straw is also assessed. In addition, the prospects for the use of energy from husks or straw in the processing of rice bran are reviewed.

  1. Seasonal prevalence and succession of rice field breeding mosquitoes of central Gujarat.

    PubMed

    Kant, R; Pandey, S D; Sharma, R C

    1992-09-01

    Studies on seasonal prevalence and succession of mosquitoes in rice fields, revealed the dominance of Anopheles culicifacies and An. subpictus in newly transplanted fields during early months of rice cultivation, which was later replaced by the species like An. annularis, An. barbirostris, An. nigerrimus and An. tessellatus with the growth in plant height. Among culicines, except Cx. quinquefasciatus other species were prevalent during growing and later stages of the rice crop. Larval density was found inversely proportional to the height of plants, whereas species diversity maximized during growing phase due to equitable number of specimen among species. PMID:1344947

  2. Cultivating an entrepreneurial mindset.

    PubMed

    Matheson, Sandra A

    2013-01-01

    Now as never before, familiar challenges require bold, novel approaches. Registered dietitians will benefit by cultivating an entrepreneurial mindset that involves being comfortable with uncertainty, learning to take calculated risks, and daring to just try it. An entrepreneur is someone who takes risks to create something new, usually in business. But the entrepreneurial mindset is available to anyone prepared to rely only on their own abilities for their economic security and expect no opportunity without first creating value for others. PMID:24018008

  3. [Impacts of climate warming on growth period and yield of rice in Northeast China during recent two decades].

    PubMed

    Hou, Wen-jia; Geng, Ting; Chen, Qun; Chen, Chang-qing

    2015-01-01

    By using rice growth period, yield and climate observation data during the recent two decades, the impact of climate warming on rice in Northeast China was investigated by mathematical statistics methods. The results indicated that in the three provinces of Northeast China, the average, maximum and minimum temperatures in rice growing season were on the. rise, and the rainfall presented a downward trend during 1989-2009. Compared to 1990s, the rice whole growth periods of Heilongjiang, Jilin and Liaoning provinces in 2000s were prolonged 14 d, 4.5 d and 5.1 d, respectively. The increase of temperature in May, June and September could extend the rice growth period, while that in July would shorten the growth duration. The rice growth duration of registered varieties and experiment sites had a similar increasing trend in Northeast China except for the Heilongjiang Province, and the extension of registered varieties growth period was the main factor causing the prolonged growth period of rice at experiment sites. The change in daily average, minimum and maximum temperatures all could affect the rice yield in Northeast China. The increasing temperature significantly increased the rice yield in Heilongjiang Province, especially in the west region of Sanjiang Plain. Except for the south of Liaoning Province, rice yields in other regions of Northeast China were promoted by increasing temperature. Proper measures for breeding, cultivation and farming, could be adopted to fully improve the adaptation of rice to climate warming in Northeast China. PMID:25985677

  4. Using NOAA/AVHRR based remote sensing data and PCR method for estimation of Aus rice yield in Bangladesh

    NASA Astrophysics Data System (ADS)

    Nizamuddin, Mohammad; Akhand, Kawsar; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

    2015-06-01

    Rice is a dominant food crop of Bangladesh accounting about 75 percent of agricultural land use for rice cultivation and currently Bangladesh is the world's fourth largest rice producing country. Rice provides about two-third of total calorie supply and about one-half of the agricultural GDP and one-sixth of the national income in Bangladesh. Aus is one of the main rice varieties in Bangladesh. Crop production, especially rice, the main food staple, is the most susceptible to climate change and variability. Any change in climate will, thus, increase uncertainty regarding rice production as climate is major cause year-to-year variability in rice productivity. This paper shows the application of remote sensing data for estimating Aus rice yield in Bangladesh using official statistics of rice yield with real time acquired satellite data from Advanced Very High Resolution Radiometer (AVHRR) sensor and Principal Component Regression (PCR) method was used to construct a model. The simulated result was compared with official agricultural statistics showing that the error of estimation of Aus rice yield was less than 10%. Remote sensing, therefore, is a valuable tool for estimating crop yields well in advance of harvest, and at a low cost.

  5. Determinants for grading Malaysian rice

    NASA Astrophysics Data System (ADS)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  6. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.)

    PubMed Central

    Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice. PMID:26752408

  7. A Built-In Mechanism to Mitigate the Spread of Insect-Resistance and Herbicide-Tolerance Transgenes into Weedy Rice Populations

    PubMed Central

    Liu, Chengyi; Li, Jingjing; Gao, Jianhua; Shen, Zhicheng; Lu, Bao-Rong; Lin, Chaoyang

    2012-01-01

    Background The major challenge of cultivating genetically modified (GM) rice (Oryza sativa) at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea). The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. Methodology/Principal Findings An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13) and two weedy rice strains (PI-63 and PI-1401). Conclusions/Significance Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations. PMID:22359609

  8. From Early Domesticated Rice of the Middle Yangtze Basin to Millet, Rice and Wheat Agriculture: Archaeobotanical Macro-Remains from Baligang, Nanyang Basin, Central China (6700-500 BC).

    PubMed

    Deng, Zhenhua; Qin, Ling; Gao, Yu; Weisskopf, Alison Ruth; Zhang, Chi; Fuller, Dorian Q

    2015-01-01

    Baligang is a Neolithic site on a northern tributary of the middle Yangtze and provides a long archaeobotanical sequence from the Seventh Millennium BC upto the First Millennium BC. It provides evidence for developments in rice and millet agriculture influenced by shifting cultural affiliation with the north (Yangshao and Longshan) and south (Qujialing and Shijiahe) between 4300 and 1800 BC. This paper reports on plant macro-remains (seeds), from systematic flotation of 123 samples (1700 litres), producing more than 10,000 identifiable remains. The earliest Pre-Yangshao occupation of the sites provide evidence for cultivation of rice (Oryza sativa) between 6300-6700 BC. This rice appears already domesticated in on the basis of a dominance of non-shattering spikelet bases. However, in terms of grain size changes has not yet finished, as grains are still thinner than more recent domesaticated rice and are closer in grain shape to wild rices. This early rice was cultivated alongside collection of wild staple foods, especially acorns (Quercus/Lithicarpus sensu lato). In later periods the sites has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum). Soybean appears on the site in the Shijiahe period (ca.2500 BC) and wheat (Triticum cf. aestivum) in the Late Longshan levels (2200-1800 BC). Weed flora suggests an intensification of rice agriculture over time with increasing evidence of wetland weeds. We interpret these data as indicating early opportunistic cultivation of alluvial floodplains and some rainfed rice, developing into more systematic and probably irrigated cultivation starting in the Yangshao period, which intensified in the Qujialing and Shijiahe period, before a shift back to an emphasis on millets with the Late Longshan cultural influence from the north. PMID:26460975

  9. From Early Domesticated Rice of the Middle Yangtze Basin to Millet, Rice and Wheat Agriculture: Archaeobotanical Macro-Remains from Baligang, Nanyang Basin, Central China (6700–500 BC)

    PubMed Central

    Deng, Zhenhua; Qin, Ling; Gao, Yu; Weisskopf, Alison Ruth; Zhang, Chi; Fuller, Dorian Q.

    2015-01-01

    Baligang is a Neolithic site on a northern tributary of the middle Yangtze and provides a long archaeobotanical sequence from the Seventh Millennium BC upto the First Millennium BC. It provides evidence for developments in rice and millet agriculture influenced by shifting cultural affiliation with the north (Yangshao and Longshan) and south (Qujialing and Shijiahe) between 4300 and 1800 BC. This paper reports on plant macro-remains (seeds), from systematic flotation of 123 samples (1700 litres), producing more than 10,000 identifiable remains. The earliest Pre-Yangshao occupation of the sites provide evidence for cultivation of rice (Oryza sativa) between 6300–6700 BC. This rice appears already domesticated in on the basis of a dominance of non-shattering spikelet bases. However, in terms of grain size changes has not yet finished, as grains are still thinner than more recent domesaticated rice and are closer in grain shape to wild rices. This early rice was cultivated alongside collection of wild staple foods, especially acorns (Quercus/Lithicarpus sensu lato). In later periods the sites has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum). Soybean appears on the site in the Shijiahe period (ca.2500 BC) and wheat (Triticum cf. aestivum) in the Late Longshan levels (2200–1800 BC). Weed flora suggests an intensification of rice agriculture over time with increasing evidence of wetland weeds. We interpret these data as indicating early opportunistic cultivation of alluvial floodplains and some rainfed rice, developing into more systematic and probably irrigated cultivation starting in the Yangshao period, which intensified in the Qujialing and Shijiahe period, before a shift back to an emphasis on millets with the Late Longshan cultural influence from the north. PMID:26460975

  10. Proposal of a growth chamber for growing Super-Dwarf Rice in Space Agriculture

    NASA Astrophysics Data System (ADS)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Tsukamoto, Koya; Yamashita, Youichirou; Hirai, Takehiro

    Space agriculture needs to be considered to supply food for space crew who stay in space over an extended time period. So far crops such as wheat, onion, oat, pea and lettuce grew to explore the possibility of space agriculture. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. However, the plant height of standard rice cultivars is relatively long, requiring much space. In addition, rice plants require higher light intensities for greater yield. For these reasons, it is difficult to establish facilities for rice culture in a limited space with a low cost. We propose to employee a super-dwarf cultivar and a small growth chamber with a new type of LEDs. The super-dwarf rice is a short-grain japonica variety and the plant height is approximately 20 cm that is one-fifth as tall as standard cultivars. The LED light used as a light source for this study can provide full spectrum of 380 nm to 750 nm. Air temperature and humidity were controlled by a Peltier device equipped in the chamber. The characteristics of the new type of LEDs and other equipments of the chamber and the ground based performance of super-dwarf rice plants grown in the chamber will be reported.

  11. Cultivating a Critical Race Consciousness for African American School Success

    ERIC Educational Resources Information Center

    Carter, Dorinda J.

    2008-01-01

    In the field of education, much of the research on Black student achievement focuses on cultural and/or structural explanations for the academic outcomes of these adolescents. A vast amount of the research on Black student achievement perpetuates a continuous discussion of Black underachievement. Race continues to remain central across discussions…

  12. Fermentation Quality and Additives: A Case of Rice Straw Silage

    PubMed Central

    Oladosu, Yusuff; Magaji, Usman; Hussin, Ghazali; Ramli, Asfaliza; Miah, Gous

    2016-01-01

    Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw. PMID:27429981

  13. Fermentation Quality and Additives: A Case of Rice Straw Silage.

    PubMed

    Oladosu, Yusuff; Rafii, Mohd Y; Abdullah, Norhani; Magaji, Usman; Hussin, Ghazali; Ramli, Asfaliza; Miah, Gous

    2016-01-01

    Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw. PMID:27429981

  14. The oryza map alignment project: the golden path to unlocking the genetic potential of wild rice species.

    PubMed

    Wing, Rod A; Ammiraju, Jetty S S; Luo, Meizhong; Kim, Hyeran; Yu, Yeisoo; Kudrna, Dave; Goicoechea, Jose L; Wang, Wenming; Nelson, Will; Rao, Kiran; Brar, Darshan; Mackill, Dave J; Han, Bin; Soderlund, Cari; Stein, Lincoln; SanMiguel, Phillip; Jackson, Scott

    2005-09-01

    The wild species of the genus Oryza offer enormous potential to make a significant impact on agricultural productivity of the cultivated rice species Oryza sativa and Oryza glaberrima. To unlock the genetic potential of wild rice we have initiated a project entitled the 'Oryza Map Alignment Project' (OMAP) with the ultimate goal of constructing and aligning BAC/STC based physical maps of 11 wild and one cultivated rice species to the International Rice Genome Sequencing Project's finished reference genome--O. sativa ssp. japonica c. v. Nipponbare. The 11 wild rice species comprise nine different genome types and include six diploid genomes (AA, BB, CC, EE, FF and GG) and four tetrapliod genomes (BBCC, CCDD, HHKK and HHJJ) with broad geographical distribution and ecological adaptation. In this paper we describe our strategy to construct robust physical maps of all 12 rice species with an emphasis on the AA diploid O. nivara--thought to be the progenitor of modern cultivated rice. PMID:16217601

  15. Spotlight on rice: an update from the Rice Division

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This short paper is a 'spotlight' on the Rice Division of the Marican Association of Cereal Chemists, International and features an update and future challenges in rice research and industry. Since rice is consumed largely as milled white rice intact kernals, size, shape, color, appearance, function...

  16. Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal.

    PubMed

    Arao, Tomohito; Maejima, Yuji; Baba, Koji

    2011-10-01

    Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean. PMID:21782301

  17. Transgenic strategies to confer resistance against viruses in rice plants

    PubMed Central

    Sasaya, Takahide; Nakazono-Nagaoka, Eiko; Saika, Hiroaki; Aoki, Hideyuki; Hiraguri, Akihiro; Netsu, Osamu; Uehara-Ichiki, Tamaki; Onuki, Masatoshi; Toki, Seichi; Saito, Koji; Yatou, Osamu

    2014-01-01

    Rice (Oryza sativa L.) is cultivated in more than 100 countries and supports nearly half of the world’s population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. Many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA interference (RNAi), also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral “Achilles’ heel” gene to target for RNAi attack when engineering plants. PMID:24454308

  18. Rice (Oryza) hemoglobins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  19. Registration of 'Cybonnet' Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Cybonnet’ rice is a high-yielding, short-season, long-grain cultivar. It originated form the cross ‘Cypress’//’Newbonnet’/’Katy’ made at the University of Arkansas Rice Research and Extension Center in Stuttgart, AR. Cybonnet is similar in maturity to ‘Kaybonnet’ and ‘Wells’, is a simidwarf culti...

  20. Making rice even healthier!

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a naturally healthy food, but what if it could be made even healthier? Would Americans eat more rice if it could be advertised to be a 'New and Improved' source of calcium to promote bone growth, or iron to prevent anemia? Grocery stores are full of foods that are vitamin enhanced to attract...

  1. Registration of 'Medark' Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Medark’ rice is a high-yielding, early maturing, semidwarf, medium-grain cultivar. It originated from the cross ‘Bengal’/’Short Rico’ and is similar in maturity to Bengal. It has improved disease resistance to rice blase, brown spot and straighthead. Medark has a lodging resistance slightly less...

  2. Rice blast disease in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is an important agricultural commodity in Texas, with an economic impact of more than $1 billion annually. Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases in rice. Texas Rice Belt provides a warm, humid climate favorable for the infection and reproduction of M....

  3. Rice and red rice interference. II. Rice response to population densities of three red rice (Oryza sativa) ecotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice, which grows taller and produces more tillers than domestic rice and shatters most of its seeds early, is a major weed in many rice-growing areas of the world. Field experiments were conducted at Stuttgart, AR in 1997 and 1998 to evaluate the growth response of the Kaybonnet (KBNT) rice cul...

  4. Cultivating the Genius of Black Children: Strategies to Close the Achievement Gap in the Early Years

    ERIC Educational Resources Information Center

    Sullivan, Debra Ren-Etta

    2016-01-01

    There has been much attention given to the opportunity gap between white and minority students, especially African American children. Using research and years of experience "Cultivating the Genius of Black Children" is able to break down the cultural influences on learning style and provides a practical approach to helping Black children…

  5. Effects of aqueous extract of soil-like substrate made from three different materials on seed germination and seedling growth of rice

    NASA Astrophysics Data System (ADS)

    Shao, Lingzhi; Fu, Yuming; Fu, Wenting; Yan, Min; Li, Leyuan; Liu, Hong

    2014-03-01

    Biologically processing rice and wheat straws into soil-like substrate (SLS) and then reusing them in plant cultivation system to achieve waste recycle is very crucially important in Bioregenerative life support system (BLSS). However, rice is a plant with strong allelopathic potential. It is not clear yet that what kinds of raw materials can be processed into proper SLS to grow rice in BLSS. Therefore, in this study, the aqueous extract of SLS made from three different materials including rice straw, wheat straw and rice-wheat straw mixture was utilized to investigate its effects on the seed germination and seedling growth of rice. The gradients of the extract concentrations (soil:water) were 1:3, 1:5, 1:9, and 1:15 with deionized water used as control. The effects of different types of SLS on seed germination and seedling vitality of rice were confirmed by analyzing the germination rate, seedling length, root length, the fresh weight and other indicants. In addition, based on the analysis towards pH, organic matter composition and other factors of the SLS as well as the chlorophyll, hormone content of rice, and the mechanism of the inhibition was speculated in order to explore the preventive methods of the phenomenon. Finally, the feasibility of cultivating rice on SLSs made from the raw materials mentioned above was evaluated and wheat raw was determined as the most appropriate material for growing rice.

  6. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  7. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  8. Gene flow from weedy red rice (Oryza sativa L.) to cultivated rice and fitness of hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gene transfer from weeds to crops could produce weedy individuals that might impact upon the evolutionary dynamics of weedy populations, the persistence of escaped genes in agroecosystems and approaches to weed management and containment of transgenic crops. The present aim was to quantify the gene ...

  9. Assimilation of MODIS-derived LAI by radiative transfer modelling to crop growth simulation model for rice crop monitoring and yield estimation in the Mekong delta, Vietnam

    NASA Astrophysics Data System (ADS)

    Nguyen, H.; de Bie, K.; Verhoef, W.

    2014-12-01

    Successful monitoring of rice crops and estimation of its yields in Mekong delta provide vital information to government agencies, rice production stakeholders and insurance companies in making their decisions and plans to establish solutions to protect rice smallholders from the risks involved. Remote sensing-based information promises a cost-effective way to observe rice crop growth in the largest rice producing region of Vietnam. For an extensive rice cultivation region as the Mekong delta, the use of divergence statistic to extract information from long-term or hypertemporal optical remote sensing NDVI profile to map rice cropping patterns has shown a high degree of success. The result map provides accurate information on where rice grew, when it was seeded and harvested, how many time it was cultivated every year. In addition, by using 8-day MODIS TERRA surface reflectance in Soil-Leaf-Canopy (SLC) radiative transfer model, 70 percent variation of seasonal rice LAI values was able to capture, making it useful to be assimilated into a rice crop growth simulation model (ORYZA 2000) to estimate the regional rice production in the season of 2008-2009. Tested results from 56 rice fields located in different rice cropping patterns showed that yields estimated using ORYZA2000 can explain 83 percent variation of field measured yields. However, simulated yields by ORYZA 2000 were used to overestimate by the model since some of model parameters could not be recalibrated due to the lack of field experiment data. This suggest that in the future, in order to gain a better results of rice crop monitoring and yield estimation, apart from improving the estimation of MODIS -derived LAIs by using SLC, calibrating crop growth simulation's parameter have to be taken into account.

  10. Loss of floral repressor function adapts rice to higher latitudes in Europe

    PubMed Central

    Gómez-Ariza, Jorge; Galbiati, Francesca; Goretti, Daniela; Brambilla, Vittoria; Shrestha, Roshi; Pappolla, Andrea; Courtois, Brigitte; Fornara, Fabio

    2015-01-01

    The capacity to discriminate variations in day length allows plants to align flowering with the most favourable season of the year. This capacity has been altered by artificial selection when cultivated varieties became adapted to environments different from those of initial domestication. Rice flowering is promoted by short days when HEADING DATE 1 (Hd1) and EARLY HEADING DATE 1 (Ehd1) induce the expression of florigenic proteins encoded by HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1). Repressors of flowering antagonize such induction under long days, maintaining vegetative growth and delaying flowering. To what extent artificial selection of long day repressor loci has contributed to expand rice cultivation to Europe is currently unclear. This study demonstrates that European varieties activate both Hd3a and RFT1 expression regardless of day length and their induction is caused by loss-of-function mutations at major long day floral repressors. However, their contribution to flowering time control varies between locations. Pyramiding of mutations is frequently observed in European germplasm, but single mutations are sufficient to adapt rice to flower at higher latitudes. Expression of Ehd1 is increased in varieties showing reduced or null Hd1 expression under natural long days, as well as in single hd1 mutants in isogenic backgrounds. These data indicate that loss of repressor genes has been a key strategy to expand rice cultivation to Europe, and that Ehd1 is a central node integrating floral repressive signals. PMID:25732533

  11. Selection of Tolerant Rice Germplasm Through Phenotypic and Genotypic Evaluation for Germination Under Low Temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low temperature germinability (LTG) is an important trait for stand establishment in the direct-seeding method of rice cultivation. In temperate growing regions, water temperature during sowing season is frequently below 15°C resulting in poor crop establishment. The objective of this study was to s...

  12. Unraveling the rich phenotypic and genetic diversity in rice for varietal improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) has two distinct varietal groups identified as the indica and japonica subspecies. With the advent of molecular markers the indica subspecies was divided into the indica and aus subpopulation groups and the japonica subspecies into the aromatic, tropical japon...

  13. Unraveling the rich phenotypic and genetic diversity in rice for varietal improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) has two distinct varietal groups identified as the indica and japonica subspecies. With the advent of molecular markers the indica subspecies was divided into the indica and aus subpopulation groups and the japonica subspecies into the aromatic, tropical japo...

  14. Selection of tolerant rice germplasm through phenotypic and genotypic evaluation for germination under low temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low temperature germinability (LTG) is an important trait for stand establishment in the direct-seeding method of rice cultivation. In temperate growing regions, water temperature during sowing season is frequently below 15°C resulting in poor crop establishment. The objective of this study was to s...

  15. Sensitivity to a phytotoxin from Rhizoctonia solani correlates with sheath blight susceptibility in rice.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheath Blight is widely regarded as one of the most important diseases of cultivated rice and germplasm improvement is essential for disease management. Genetic sources of tolerance for this disease are known, however, complex quantitative inheritance and high environmental variability make phenoty...

  16. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice...) (percent) Chalky kernels 1,2 In long grain rice (percent) In medium or short grain rice (percent)...

  17. The Cultivated Mind: From Mental Mediation to Cultivation.

    ERIC Educational Resources Information Center

    Josephs, Ingrid E.; Fuhrer, Urs

    1998-01-01

    Examines Simmel's principle of cultivation whereby the cultivated mind is constructed through ongoing transactions of people with their cultural environment, cultural forms currently overlooked. Cultural forms result from externalizations of former person-culture transactions. Argues that development is structured through person-culture…

  18. Bioconversion of rice straw into a soil-like substrate

    NASA Astrophysics Data System (ADS)

    Yu, Chengying; Liu, Hong; Xing, Yidong; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.

    To increase the closure of bioregenerative life support systems (BLSS), the bioconversion of rice straw into a soil-like substrate (SLS) by mushrooms and worms has been studied. The results showed that rice straw could be treated better by aerobic fermentation and succeeding growth of mushrooms Pleurotus ostreatus. In this process the total content of lignocellulose in the straw was removed by 37.74%. Furthermore, 46.68 g (fresh weight) of mushrooms could be produced from 100.0 g (dry weight) of rice straw. During the conversion of rice straw into a starting SLS by mushrooms and worms, the matter loss was 77.31%. The lettuce has been planted in the SLS and the yield when lettuce was cultivated on the SLS (8.77gm-2day-1) was comparable to the yield obtained on the nutrient solution. In addition, the silicon in the SLS ash can reach upto 32% and the circulation of it is expected during the growth of rice.

  19. Biochar amendment reduced methylmercury accumulation in rice plants.

    PubMed

    Shu, Rui; Wang, Yongjie; Zhong, Huan

    2016-08-01

    There is growing concern about methylmercury (MeHg) accumulation in rice grains and thus enhanced dietary exposure to MeHg in Asian countries. Here, we explored the possibility of reducing grain MeHg levels by biochar amendment, and the underlying mechanisms. Pot (i.e., rice cultivation in biochar amended soils) and batch experiments (i.e., incubation of amended soils under laboratory conditions) were carried out, to investigate MeHg dynamics (i.e., MeHg production, partitioning and phytoavailability in paddy soils, and MeHg uptake by rice) under biochar amendment (1-4% of soil mass). We demonstrate for the first time that biochar amendment could evidently reduce grain MeHg levels (49-92%). The declines could be attributed to the combined effects of: (1) increased soil MeHg concentrations, probably explained by the release of sulfate from biochar and thus enhanced microbial production of MeHg (e.g., by sulfate-reducing bacteria), (2) MeHg immobilization in soils, facilitated by the large surface areas and high organosulfur content of biochar, and (3) biodilution of MeHg in rice grains, due to the increased grain biomass under biochar amendment (35-79%). These observations together with mechanistic explanations improve understanding of MeHg dynamics in soil-rice systems, and support the possibility of reducing MeHg phytoaccumulation under biochar amendment. PMID:27045620

  20. Rice management interventions to mitigate greenhouse gas emissions: a review.

    PubMed

    Hussain, Saddam; Peng, Shaobing; Fahad, Shah; Khaliq, Abdul; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

    2015-03-01

    Global warming is one of the gravest threats to crop production and environmental sustainability. Rice, the staple food of more than half of the world's population, is the most prominent cause of greenhouse gas (GHG) emissions in agriculture and gives way to global warming. The increasing demand for rice in the future has deployed tremendous concerns to reduce GHG emissions for minimizing the negative environmental impacts of rice cultivation. In this review, we presented a contemporary synthesis of existing data on how crop management practices influence emissions of GHGs in rice fields. We realized that modifications in traditional crop management regimes possess a huge potential to overcome GHG emissions. We examined and evaluated the different possible options and found that modifying tillage permutations and irrigation patterns, managing organic and fertilizer inputs, selecting suitable cultivar, and cropping regime can mitigate GHG emissions. Previously, many authors have discussed the feasibility principle and the influence of these practices on a single gas or, in particular, in the whole agricultural sector. Nonetheless, changes in management practices may influence more than one gas at the same time by different mechanisms or sometimes their effects may be antagonistic. Therefore, in the present attempt, we estimated the overall global warming potential of each approach to consider the magnitude of its effects on all gases and provided a comprehensive assessment of suitable crop management practices for reducing GHG emissions in rice culture. PMID:25354441

  1. Assessing energy efficiencies and greenhouse gas emissions under bioethanol-oriented paddy rice production in northern Japan.

    PubMed

    Koga, Nobuhisa; Tajima, Ryosuke

    2011-03-01

    To establish energetically and environmentally viable paddy rice-based bioethanol production systems in northern Japan, it is important to implement appropriately selected agronomic practice options during the rice cultivation step. In this context, effects of rice variety (conventional vs. high-yielding) and rice straw management (return to vs. removal from the paddy field) on energy inputs from fuels and consumption of materials, greenhouse gas emissions (fuel and material consumption-derived CO(2) emissions as well as paddy soil CH(4) and N(2)O emissions) and ethanol yields were assessed. The estimated ethanol yield from the high-yielding rice variety, "Kita-aoba" was 2.94 kL ha(-1), a 32% increase from the conventional rice variety, "Kirara 397". Under conventional rice production in northern Japan (conventional rice variety and straw returned to the paddy), raising seedlings, mechanical field operations, transportation of harvested unhulled brown rice and consumption of materials (seeds, fertilizers, biocides and agricultural machinery) amounted to 28.5 GJ ha(-1) in energy inputs. The total energy input was increased by 14% by using the high-yielding variety and straw removal, owing to increased requirements for fuels in harvesting and transporting harvested rice as well as in collecting, loading and transporting rice straw. In terms of energy efficiency, the variation among rice variety and straw management scenarios regarding rice varieties and rice straw management was small (28.5-32.6 GJ ha(-1) or 10.1-14.0 MJ L(-1)). Meanwhile, CO(2)-equivalent greenhouse gas emissions varied considerably from scenario to scenario, as straw management had significant impacts on CH(4) emissions from paddy soils. When rice straw was incorporated into the soil, total CO(2)-equivalent greenhouse gas emissions for "Kirara 397" and "Kita-aoba" were 25.5 and 28.2 Mg CO(2) ha(-1), respectively; however, these emissions were reduced notably for the two varieties when rice straw

  2. Productivity of wet soils: Biomass of cultivated and natural vegetation

    SciTech Connect

    Johnston, C.A.

    1988-12-01

    Wet soils, soils which have agronomic limitations because of excess water, comprise 105 million acres of non-federal land in the conterminous United States. Wet soils which support hydrophytic plants are ''wetlands'', and are some of the most productive natural ecosystems in the world. When both above- and belowground productivity are considered, cattail (Typha latifolia) is the most productive temperate wetland species (26.4 Mg/ha/year). Both cattail and reed (Phragmites australis) have aboveground productivities of about 13 Mg/ha/year. Although average aboveground yields of reed canarygrass (Phalaris arundinacea) are lower (9.5 Mg/ha/year), techniques for its establishment and cultivation are well-developed. Other herbaceous wetland species which show promise as biomass crops include sedge (Carex spp.), river bulrush (Scirpus fluviatilis) and prairie cordgrass (Spartina pectinata). About 40% of wet soils in the conterminous US are currently cultivated, and they produce one-quarter of the major US crops. Most of this land is artificially drained for crops such as corn, soybeans, and vegetables. US wetlands are drained for agriculture at the rate of 223,000 ha/yr. Paddies flooded with water are used to grow rice, cranberries, and wild rice. Forage and live sphagnum moss are products of undrained wetlands. A number of federal and state regulations apply to the draining or irrigation of wetlands, but most do not seriously restrict their use for agriculture. 320 refs., 36 tabs.

  3. Genetic diversity and classification of Oryza sativa with emphasis on Chinese rice germplasm

    PubMed Central

    Wang, C-H; Zheng, X-M; Xu, Q; Yuan, X-P; Huang, L; Zhou, H-F; Wei, X-H; Ge, S

    2014-01-01

    Despite extensive studies on cultivated rice, the genetic structure and subdivision of this crop remain unclear at both global and local scales. Using 84 nuclear simple sequence repeat markers, we genotyped a panel of 153 global rice cultivars covering all previously recognized groups and 826 cultivars representing the diversity of Chinese rice germplasm. On the basis of model-based grouping, neighbour-joining tree and principal coordinate analysis, we confirmed the widely accepted five major groups of rice cultivars (indica, aus, aromatic, temperate japonica and tropical japonica), and demonstrated that rayada rice was unique in genealogy and should be treated as a new (the sixth) major group of rice germplasm. With reference to the global classification of rice cultivars, we identified three major groups (indica, temperate japonica and tropical japonica) in Chinese rice germplasm and showed that Chinese temperate japonica contained higher diversity than that of global samples, whereas Chinese indica and tropical japonica maintained slightly lower diversity than that present in the global samples. Particularly, we observed that all seasonal, drought-tolerant and endosperm types occurred within each of three major groups of Chinese cultivars, which does not support previous claims that seasonal differentiation exists in Indica and drought-tolerant differentiation is present in Japonica. It is most likely that differentiation of cultivar types arose multiple times stemming from artificial selection for adaptation to local environments. PMID:24326293

  4. The role of irrigation techniques in arsenic bioaccumulation in rice (Oryza sativa L.).

    PubMed

    Spanu, Antonino; Daga, Leonardo; Orlandoni, Anna Maria; Sanna, Gavino

    2012-08-01

    The bioaccumulation of arsenic compounds in rice is of great concern worldwide because rice is the staple food for billions of people and arsenic is one of the most toxic and carcinogenic elements at even trace amounts. The uptake of arsenic compounds in rice comes mainly from its interaction with system soil/water in the reducing conditions typical of paddy fields and is influenced by the irrigation used. We demonstrate that the use of sprinkler irrigation produces rice kernels with a concentration of total arsenic about fifty times lower when compared to rice grown under continuous flooding irrigation. The average total amount of arsenic, measured by a fully validated ICP-MS method, in 37 rice grain genotypes grown with sprinkler irrigation was 2.8 ± 2.5 μg kg(-1), whereas the average amount measured in the same genotypes grown under identical conditions, but using continuous flooding irrigation was 163 ± 23 μg kg(-1). In addition, we find that the average concentration of total arsenic in rice grains cultivated under sprinkler irrigation is close to the total arsenic concentration found in irrigation waters. Our results suggest that, in our experimental conditions, the natural bioaccumulation of this element in rice grains may be completely circumvented by adopting an appropriate irrigation technique. PMID:22765219

  5. How to cultivate Ectocarpus.

    PubMed

    Coelho, Susana M; Scornet, Delphine; Rousvoal, Sylvie; Peters, Nick T; Dartevelle, Laurence; Peters, Akira F; Cock, J Mark

    2012-02-01

    This article describes the standard procedure for growing Ectocarpus in the laboratory. The culture is started with partheno-sporophyte (or sporophyte) filaments because this is the stage that is usually maintained in strain collections. The standard medium is Provasoli-enriched natural seawater (PES), but Ectocarpus can also be grown in artificial seawater, which allows more precise control over the culture conditions. The algae can be cultivated either in plastic Petri dishes or in 10-L bottles with bubbling, if large amounts of biomass are required. Standard growth conditions are 13°C with a 12h/12h d/night cycle and 20 µmol photons m(-2) s(-1) irradiance using daylight-type fluorescent tubes. All manipulations of Ectocarpus cultures should be performed in a clean environment (if possible, under a laminar flow hood). Forceps should be dipped in ethanol and allowed to dry under the hood. PMID:22301662

  6. Hybrid origins of cultivated potatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild and cultivated potatoes, Solanum section Petota, is taxonomically difficult, partly because of interspecific hybridization at both the diploid and polyploid levels. The taxonomy of cultivated potatoes is particularly controversial. With DNA sequence data of the GBSSI (waxy) gene we here infer r...

  7. Micrometeorological principles of protected cultivation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" consi...

  8. Starting from grape cultivation.

    PubMed

    Yoshida, A

    1992-06-01

    Rapid population growth can only be stopped by lowering the fertility rate. The UNFPA recommends improving the employment opportunities for women as the single best way of achieving this reduction. An example of this phenomenon is the grape cultivation in the Nordeste (Northeastern) region of Brazil. This area is the poorest part of Brazil and has the highest proportion of indigent people. These people have been deforesting the Amazon in search of a better life. What they have done is sterilize the land and turned a tropical rain forest into a desert. In an effort to reverse this trend, grape cultivation has been introduced in an area called Petrolina. The area is very dry with less than 500 mm of precipitation annually. They do have access to a 5000 square kilometer artificial lake (the largest in the world) and the 3rd largest river in Brazil (the Sao Francisco). In an effort to avoid using agricultural medicines, the vines are fertilized with organic matter created on the farm and little or no pesticides are used since pests do not live in such an arid region. It has taken 20 years of trial and error, but the quality of the grapes is now very high and is competitive on the world market. Because of climate and location, harvesting is done year round which increases the productivity of the land. The farm managers have found that married women make the best workers and have the highest level of productivity. Age at 1st marriage averages 24-25, compared with 15-16 for unemployed women in the same area. The fertility rate averages 50% of that for unemployed women in the same area. Agricultural development offers the best opportunity for the women of developing countries. It can pay a high wage, reduce fertility, and replant desert areas. PMID:12285551

  9. Localization and speciation of mercury in brown rice with implications for pan-Asian public health.

    PubMed

    Meng, Bo; Feng, Xinbin; Qiu, Guangle; Anderson, Christopher W N; Wang, Jianxu; Zhao, Lei

    2014-07-15

    Cultivation of paddy rice for human consumption is a dominant agricultural activity throughout Asia. High levels of mercury (Hg) in rice grain pose a potential threat to human health, although the extent of risk is dependent on the chemical speciation of Hg inside the grain. We have investigated the speciation and localization of Hg in three fractions of rice grain (hull, bran, and white rice) collected from a Hg-contaminated region in China. On a mass basis, the majority of inorganic mercury (IHg) in a rice grain is found in hull and bran. However, the majority of the more toxic species methyl mercury (MeHg) is found in edible white rice. Our data show that during grain processing, most of the IHg (∼78%) is eliminated, but the majority of the MeHg remains in the food product (∼80%). Synchrotron radiation microscopic X-ray fluorescence (SR-μXRF) mapping shows strong localization of Hg at the surface of brown rice grains, corresponding to the pericarp and aleurone layer. We infer that this Hg is predominantly IHg absorbed from the atmosphere. Based on X-ray absorption near-edge spectroscopy (XANES) data we propose that IHg in bran is primarily bound to cysteine, and is associated with phytochelatins. Consequently, IHg is largely immobile and restricted to the outer layers of rice grain. MeHg in bran is primarily bound to cysteine and is associated with proteins. However, this MeHg-cysteine association behaves like a mobile nutrient and is actively transported to the endosperm during seed ripening. Concentration of MeHg-cysteine in white rice has implications for public health. There is growing evidence for Hg contamination of rice throughout Asia due to point and diffuse sources of Hg pollution. The magnitude of the associated risk must be quantified through better understanding of the localization and speciation of mercury in rice. Our work makes an effort to contribute to this understanding. PMID:24925231

  10. Resequencing rice genomes: an emerging new era of rice genomics.

    PubMed

    Huang, Xuehui; Lu, Tingting; Han, Bin

    2013-04-01

    Rice is a model system for crop genomics studies. Much of the early work on rice genomics focused on analyzing genome-wide genetic variation to further understand rice gene functions in agronomic traits and to generate data and resources for rice research. The advent of next-generation high-throughput DNA sequencing technologies and the completion of high-quality reference genome sequences have enabled the development of sequencing-based genotyping and genome-wide association studies (GWAS) that have significantly advanced rice genetics research. This has led to the emergence of a new era of rice genomics aimed at bridging the knowledge gap between genotype and phenotype in rice. These technologies have also led to pyramid breeding through genomics-assisted selection, which will be useful in breeding elite varieties suitable for sustainable agriculture. Here, we review the recent advances in rice genomics and discuss the future of this line of research. PMID:23295340

  11. Annual Changes of Paddy Rice Planting Areas in Northeastern Asia from MODIS images in 2000-2014

    NASA Astrophysics Data System (ADS)

    Xiao, X.; Zhang, G.; Dong, J.; Menarguez, M. A.; Kou, W.; Jin, C.; Qin, Y.; Zhou, Y.; Wang, J.; Moore, B., III

    2014-12-01

    Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, estimation of greenhouse gas (methane) emissions, and understanding avian influenza virus transmission. Over the past two decades, paddy rice cultivation has expanded northward in temperate and cold temperate zones, particularly in Northeastern China. There is a need to quantify and map changes in paddy rice planting areas in Northeastern Asia (Japan, North and South Korea, and northeast China) at annual interval. We developed a pixel- and phenology-based image analysis system, MODIS-RICE, to map the paddy rice in Northeastern Asia by using multi-temporal MODIS thermal and surface reflectance imagery. Paddy rice fields during the flooding and transplanting phases have unique physical and spectral characteristics, which make it possible for the development of an automated and robust algorithm to track flooding and transplanting phases of paddy rice fields over time. In this presentation, we will show the MODIS-based annual maps of paddy rice planting area in the Northeastern Asia from 2000-2014 (500-m spatial resolution). Accuracy assessments using high-resolution images show that the resultant paddy rice map of Northeastern Asia had a comparable accuracy to the existing products, including 2010 Landsat-based National Land Cover Dataset (NLCD) of China, the 2010 RapidEye-based paddy rice map in North Korea, and the 2010 AVNIR-2-based National Land Cover Dataset in Japan in terms of both area and spatial pattern of paddy rice. This study has demonstrated that our novel MODIS-Rice system, which use both thermal and optical MODIS data over a year, are simple and robust tools to identify and map paddy rice fields in temperate and cold temperate zones.

  12. Flood-tolerant rice reduces yield variability and raises expected yield, differentially benefitting socially disadvantaged groups

    PubMed Central

    Dar, Manzoor H.; de Janvry, Alain; Emerick, Kyle; Raitzer, David; Sadoulet, Elisabeth

    2013-01-01

    Approximately 30% of the cultivated rice area in India is prone to crop damage from prolonged flooding. We use a randomized field experiment in 128 villages of Orissa India to show that Swarna-Sub1, a recently released submergence-tolerant rice variety, has significant positive impacts on rice yield when fields are submerged for 7 to 14 days with no yield penalty without flooding. We estimate that Swarna-Sub1 offers an approximate 45% increase in yields over the current popular variety when fields are submerged for 10 days. We show additionally that low-lying areas prone to flooding tend to be more heavily occupied by people belonging to lower caste social groups. Thus, a policy relevant implication of our findings is that flood-tolerant rice can deliver both efficiency gains, through reduced yield variability and higher expected yield, and equity gains in disproportionately benefiting the most marginal group of farmers. PMID:24263095

  13. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  14. Arsenic in rice (Oryza sativa L.) related to dynamics of arsenic and silicic acid in paddy soils.

    PubMed

    Bogdan, Katja; Schenk, Manfred K

    2008-11-01

    Paddy rice is a global staple food which in some circumstances can contain high levels of the toxic element arsenic (As). In order to elucidate factors influencing As dissolution in the soil solution during paddy rice cultivation, rice (Oryza sativa L. "Selenio") was cultivated to maturity in six paddy soils in the greenhouse in 2005 and 2006. Concentrations of Mn, Fe, As, P, and silicic acid in soil solution and As concentrations in rice straw and polished rice grain were determined. There was a close relationship between Fe and As concentrations in the soil solution, suggesting that the major part of dissolved As originated from reduced iron-(hydr)oxide. However, in addition to the factors causing As dissolution in the soil, other factors influenced the uptake of As by rice. The inhibitory effect of indigenous silicic acid in the soil solution on As uptake was clearly shown. This implied that soils with high plant available Si contents resulted in low plant As contents and that Si application to soils may decrease the As content of rice. PMID:19031876

  15. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  16. Effects of extract liquid of SLS made from three different materials on seed germination and seedling growth of rice

    NASA Astrophysics Data System (ADS)

    Shao, Lingzhi; Fu, Wenting; Liu, Hong; Yan, Min; Li, Leyuan

    Rice and wheat are the main candidate crops in the bioregenerative life support system (BLSS) of China, for they are traditional food in Asia. Thus the recycling of their straws is an important issue in our BLSS, and it is a vital way to biologically process them into the soil like substrate (SLS) first and then reuse them in the plant cultivation system to achieve their recycle in BLSS. However, rice is a plant with strong allelopathic effects. And so far, it is also not clear that what kind of raw materials can be processed into proper SLS to grow rice in the BLSS. Therefore, in this study, the extract liquid of SLS made from three different materials including rice straw, wheat straw and rice-wheat mixed straw was utilized to investigate its effects on the seed germination and seedling growth of rice. The gradients of the extract concentrations (soil: water) were 1:3, 1:5, 1:9, and 1:15 with the deionized water used as control. The effects of different types of SLS on seed germination and seedling vitality of rice were confirmed by analyzing the germination rate, seedling length, root length, root fresh weight, seedling fresh weight and other indicates. In addition, based on the analysis towards pH, organic matter composition and other factors of the SLS as well as the chlorophyll and hormone content of rice, the mechanism of the inhibition was speculated and the preventive methods of this phenomenon was explored. Finally, the feasibility of cultivating rice on the SLS made from the above three kinds of raw materials was evaluated and the proper raw materials to be processed into SLS to grow rice were determined.

  17. Establishment of a rice-duck integrated farming system and its effects on soil fertility and rice disease control

    NASA Astrophysics Data System (ADS)

    Teng, Qing; Hu, Xue-Feng; Cheng, Chang; Luo, Zhi-Qing; Luo, Fan

    2015-04-01

    Rice-duck integrated farming is an ecological farming system newly established in some areas of southern China . It was reported that the ducks walking around the paddy fields is beneficial to control weed hazards and reduce rice pests and diseases. To study and evaluate the effects of the rice-duck integrated farming on soil fertility and rice disease control, a field experiment of rice cultivation was carried out in the suburb of Shanghai in 2014. It includes a treatment of raising ducks in the fields and a control without ducks. The treatment was implemented by building a duck coop nearby the experimental fields and driving 15 ducks into a plot at daytime since the early stage of rice growth. Each plot is 667 m2 in area. The treatment and control were replicated for three times. No any herbicides, pesticides, fungicides and chemical fertilizers were applied during the experiment to prevent any disturbance to duck growing and rice weed hazards and disease incidences from agrochemicals. The results are as follows: (1) The incidences of rice leaf rollers (Cnaphalocrocis medinalis) and stem borers treated with ducks, 0.45%and 1.18% on average, respectively, are lower than those of the control, 0.74% and 1.44% on average, respectively. At the late stage of rice growth, the incidence of rice sheath blight treated with ducks, 13.15% on average, is significantly lower than that of the control, 16.9% on average; and the incidence of rice planthoppers treated with ducks, 11.3 per hill on average, is also significantly lower than that of the control, 47.4 per hill on average. (2) The number of weeds in the plots treated with ducks, 8.3 per m2 on average, is significantly lower than that of the control, 87.5 m2 on average. (3) Raising ducks in the fields could also enhance soil enzyme activity and nutrient status. At the late stage of rice growth, the activities of urease, phosphatase, sucrase and catalase in the soils treated with ducks are 1.39 times, 1.40 times, 1

  18. Detection of Inorganic Arsenic in Rice Using a Field Test Kit: A Screening Method.

    PubMed

    Bralatei, Edi; Lacan, Severine; Krupp, Eva M; Feldmann, Jörg

    2015-11-17

    Rice is a staple food eaten by more than 50% of the world's population and is a daily dietary constituent in most South East Asian countries where 70% of the rice export comes from and where there is a high level of arsenic contamination in groundwater used for irrigation. Research shows that rice can take up and store inorganic arsenic during cultivation, and rice is considered to be one of the major routes of exposure to inorganic arsenic, a class I carcinogen for humans. Here, we report the use of a screening method based on the Gutzeit methodology to detect inorganic arsenic (iAs) in rice within 1 h. After optimization, 30 rice commodities from the United Kingdom market were tested with the field method and were compared to the reference method (high-performance liquid chromatography-inductively coupled plasma-mass spectrometry, HPLC-ICP-MS). In all but three rice samples, iAs compound can be determined. The results show no bias for iAs using the field method. Results obtained show quantification limits of about 50 μg kg(-1), a good reproducibility for a field method of ±12%, and only a few false positives and negatives (<10%) could only be recorded at the 2015 European Commission (EC) guideline for baby rice of 100 μg kg(-1), while none were recorded at the maximum level suggested by the World Health Organization (WHO) and implemented by the EC for polished and white rice of 200 μg kg(-1). The method is reliable, fast, and inexpensive; hence, it is suggested to be used as a screening method in the field for preselection of rice which violates legislative guidelines. PMID:26506262

  19. Trapping African fig fly (Diptera: Drosophilidae) with combinations of vinegar and wine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The African fig fly, Zaprionus indianus Gupta (Diptera: Drosophilidae), is an invasive fruit pest that has spread rapidly through much of the eastern United States. Tests were conducted in southern Florida that recorded the response of Z. indianus to baits that included Merlot wine, rice vinegar, et...

  20. Effects of Shading on Starch Pasting Characteristics of Indica Hybrid Rice (Oryza sativa L.)

    PubMed Central

    Ren, Wan-Jun; Yang, Wen-Yu

    2013-01-01

    Rice is an important staple crop throughout the world, but environmental stress like low-light conditions can negatively impact crop yield and quality. Using pot experiments and field experiments, we studied the effects of shading on starch pasting viscosity and starch content with six rice varieties for three years, using the Rapid Visco Analyser to measure starch pasting viscosity. Shading at different growth stages and in different rice varieties all affected the starch pasting characteristics of rice. The effects of shading on starch pasting viscosity at middle and later growth stages were greater than those at earlier stages. Shading enhanced breakdown but reduced hold viscosity and setback at tillering-elongation stage. Most pasting parameters changed significantly with shading after elongation stage. Furthermore, the responses of different varieties to shading differed markedly. The change scope of starch pasting viscosity in Dexiang 4103 was rather small after heading, while that in IIyou 498 and Gangyou 906 was small before heading. We observed clear tendencies in peak viscosity, breakdown, and pasting temperature of the five rice varieties with shading in 2010 and 2011. Correlation analysis indicated that the rice amylose content was negatively correlated with breakdown, but was positively correlated with setback. Based on our results, IIyou 498, Gangyou 906, and Dexiang 4103 had higher shade endurance, making these varieties most suitable for high-quality rice cultivation in low-light regions. PMID:23861872

  1. Effects of ammonium application rate on uptake of soil adsorbed amino acids by rice*

    PubMed Central

    Cao, Xiao-chuang; Ma, Qing-xu; Wu, Liang-huan; Zhu, Lian-feng; Jin, Qian-yu

    2016-01-01

    In recent years, excessive use of chemical nitrogen (N) fertilizers has resulted in the accumulation of excess ammonium (NH4 +) in many agricultural soils. Though rice is known as an NH4 +-tolerant species and can directly absorb soil intact amino acids, we still know considerably less about the role of high exogenous NH4 + content on rice uptake of soil amino acids. This experiment examined the effects of the exogenous NH4 + concentration on rice uptake of soil adsorbed glycine in two different soils under sterile culture. Our data showed that the sorption capacity of glycine was closely related to soils’ physical and chemical properties, such as organic matter and cation exchange capacity. Rice biomass was significantly inhibited by the exogenous NH4 + content at different glycine adsorption concentrations. A three-way analysis of variance demonstrated that rice glycine uptake and glycine nutritional contribution were not related to its sorption capacity, but significantly related to its glycine:NH4 + concentration ratio. After 21-d sterile cultivation, the rice uptake of adsorbed glycine accounted for 8.8%‒22.6% of rice total N uptake, which indicates that soil adsorbed amino acids theoretically can serve as an important N source for plant growth in spite of a high NH4 + application rate. However, further studies are needed to investigate the extent to which this bioavailability is realized in the field using the 13C, 15N double labeling technology.

  2. Rice Crop Monitoring and Yield Assessment with MODIS 250m Gridded Vegetation Products: A Case Study of Sa Kaeo Province, Thailand

    NASA Astrophysics Data System (ADS)

    Wijesingha, J. S. J.; Deshapriya, N. L.; Samarakoon, L.

    2015-04-01

    Billions of people in the world depend on rice as a staple food and as an income-generating crop. Asia is the leader in rice cultivation and it is necessary to maintain an up-to-date rice-related database to ensure food security as well as economic development. This study investigates general applicability of high temporal resolution Moderate Resolution Imaging Spectroradiometer (MODIS) 250m gridded vegetation product for monitoring rice crop growth, mapping rice crop acreage and analyzing crop yield, at the province-level. The MODIS 250m Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) time series data, field data and crop calendar information were utilized in this research in Sa Kaeo Province, Thailand. The following methodology was used: (1) data pre-processing and rice plant growth analysis using Vegetation Indices (VI) (2) extraction of rice acreage and start-of-season dates from VI time series data (3) accuracy assessment, and (4) yield analysis with MODIS VI. The results show a direct relationship between rice plant height and MODIS VI. The crop calendar information and the smoothed NDVI time series with Whittaker Smoother gave high rice acreage estimation (with 86% area accuracy and 75% classification accuracy). Point level yield analysis showed that the MODIS EVI is highly correlated with rice yield and yield prediction using maximum EVI in the rice cycle predicted yield with an average prediction error 4.2%. This study shows the immense potential of MODIS gridded vegetation product for keeping an up-to-date Geographic Information System of rice cultivation.

  3. Effect of rice variety and nutrient management on rice productivity in organic rice system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for organic rice has been increasing for decades. However, the information on sustainable organic rice production systems is still lacking. The objective of this study was to investigate the effects of soil amendment products, nitrogen rate, and variety on rice grain yield, yield components, ...

  4. Survey of arsenic and its speciation in rice products such as breakfast cereals, rice crackers and Japanese rice condiments.

    PubMed

    Sun, Guo-Xin; Williams, Paul N; Zhu, Yong-Guan; Deacon, Claire; Carey, Anne-Marie; Raab, Andrea; Feldmann, Joerg; Meharg, Andrew A

    2009-04-01

    Rice has been demonstrated to be one of the major contributors to arsenic (As) in human diets in addition to drinking water, but little is known about rice products as an additional source of As exposure. Rice products were analyzed for total As and a subset of samples were measured for arsenic speciation using high performance liquid chromatography interfaced with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). A wide range of rice products had total and inorganic arsenic levels that typified those found in rice grain including, crisped rice, puffed rice, rice crackers, rice noodles and a range of Japanese rice condiments as well as rice products targeted at the macrobiotic, vegan, lactose intolerant and gluten intolerance food market. Most As in rice products are inorganic As (75.2-90.1%). This study provides a wider appreciation of how inorganic arsenic derived from rice products enters the human diet. PMID:18775567

  5. Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate

    PubMed Central

    Xie, Ling; Han, Ji Hee; Lee, Sang Yeob

    2014-01-01

    Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing 3.43 × 1010 conidia/g, compared with 3.05 × 1010 conidia/g for brown rice. The addition of 2% CaCO3 + 2% CaSO4 to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time (LT50) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), KNO3 (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives. PMID:25606006

  6. Influence of Additives on the Yield and Pathogenicity of Conidia Produced by Solid State Cultivation of an Isaria javanica Isolate.

    PubMed

    Kim, Jeong Jun; Xie, Ling; Han, Ji Hee; Lee, Sang Yeob

    2014-12-01

    Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing 3.43 × 10(10) conidia/g, compared with 3.05 × 10(10) conidia/g for brown rice. The addition of 2% CaCO3 + 2% CaSO4 to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time (LT50) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), KNO3 (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives. PMID:25606006

  7. RICE IDENTITY TESTING USING DNA MARKER ANALYSIS OF PROCESSEDOR ARCHIVED RICE TISSUE AND RICE-INGREDIENT FOODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The highly regarded reputation of USA rice in the world marketplace rice has been achieved by delivering rice and rice products that meet rigorous standards of uniformity and quality. In this regard, seed dealers, farmers, millers, and processors are concerned that the rice seed they are handling is...

  8. Screening Rice Cultivars for Resistance to Bacterial Leaf Blight.

    PubMed

    Fred, Agaba Kayihura; Kiswara, Gilang; Yi, Gihwan; Kim, Kyung-Min

    2016-05-28

    Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious threats to rice production. In this study, screening of rice for resistance to BLB was carried out at two different times and locations; that is, in a greenhouse during winter and in an open field during summer. The pathogenicity of Xoo race K1 was tested on 32 Korean rice cultivars. Inoculation was conducted at the maximum tillering stage, and the lesion length was measured after 14 days of inoculation. Five cultivars, Hanareum, Namcheon, Samgdeok, Samgang, and Yangjo, were found to be resistant in both the greenhouse and open-field screenings. Expression of the plant defense-related genes JAmyb, OsNPR1, OsPR1a, OsWRKY45, and OsPR10b was observed in resistant and susceptible cultivars by qRT-PCR. Among the five genes tested, only OsPR10b showed coherent expression with the phenotypes. Screening of resistance to Xoo in rice was more accurate when conducted in open fields in the summer cultivation period than in greenhouses in winter. The expression of plant defenserelated genes after bacterial inoculation could give another perspective in elucidating defense mechanisms by using both resistant and susceptible individuals. PMID:26869604

  9. Current Status of Proteomic Studies on Defense Responses in Rice.

    PubMed

    Chen, Xifeng; Bhadauria, Vijai; Ma, Bojun

    2016-01-01

    Biotic stresses are constraints to plant growth and development negatively impacting crop production. To counter such stresses, plants have developed stress-specific adaptations as well as simultaneous responses. The efficacy and magnitude of inducible adaptive responses are dependent on activation of signaling pathways and intracellular networks by modulating expression, or abundance, and/or post-translational modification of proteins associated with defense mechanisms. Proteomics plays an important role in elucidating plant defense mechanisms by mining the differential regulation of proteins to various biotic stresses. Rice, one of the most widely cultivated food crops in world, is constantly challenged by a variety of biotic stresses, and high-throughput proteomics approaches have been employed to unravel the molecular mechanism of the biotic stresses-response in rice. In this review, we summarize the latest advances of proteomic studies on defense responses and discuss the potential relevance of the proteins identified by proteomic means in rice defense mechanism. Furthermore, we provide perspective for proteomics in unraveling the molecular mechanism of rice immunity. PMID:26364119

  10. Genetic algorithm based approach to optimize phenotypical traits of virtual rice.

    PubMed

    Ding, Weilong; Xu, Lifeng; Wei, Yang; Wu, Fuli; Zhu, Defeng; Zhang, Yuping; Max, Nelson

    2016-08-21

    How to select and combine good traits of rice to get high-production individuals is one of the key points in developing crop ideotype cultivation technologies. Existing cultivation methods for producing ideal plants, such as field trials and crop modeling, have some limits. In this paper, we propose a method based on a genetic algorithm (GA) and a functional-structural plant model (FSPM) to optimize plant types of virtual rice by dynamically adjusting phenotypical traits. In this algorithm, phenotypical traits such as leaf angles, plant heights, the maximum number of tiller, and the angle of tiller are considered as input parameters of our virtual rice model. We evaluate the photosynthetic output as a function of these parameters, and optimized them using a GA. This method has been implemented on GroIMP using the modeling language XL (eXtended L-System) and RGG (Relational Growth Grammar). A double haploid population of rice is adopted as test material in a case study. Our experimental results show that our method can not only optimize the parameters of rice plant type and increase the amount of light absorption, but can also significantly increase crop yield. PMID:27179460

  11. Drought-tolerant rice germplasm developed from an Oryza officinalis transformation-competent artificial chromosome clone.

    PubMed

    Liu, R; Zhang, H H; Chen, Z X; Shahid, M Q; Fu, X L; Liu, X D

    2015-01-01

    Oryza officinalis has proven to be a natural gene reservoir for the improvement of domesticated rice as it carries many desirable traits; however, the transfer of elite genes to cultivated rice by conventional hybridization has been a challenge for rice breeders. In this study, the conserved sequence of plant stress-related NAC transcription factors was selected as a probe to screen the O. officinalis genomic transformation-competent artificial chromosome library by Southern blot; 11 positive transformation-competent artificial chromosome clones were subsequently detected. By Agrobacterium-mediated transformation, an indica rice variety, Huajingxian 74 (HJX74), was transformed with a TAC clone harboring a NAC gene-positive genomic fragment from O. officinalis. Molecular analysis revealed that the O. officinalis genomic fragment was integrated into the genome of HJX74. The transgenic lines exhibited high tolerance to drought stress. Our results demonstrate that the introduction of stress-related transformation-competent artificial chromosome clones, coupled with a transgenic validation approach, is an effective method of transferring agronomically important genes from O. officinalis to cultivated rice. PMID:26535682

  12. Different farming and water regimes in Italian rice fields affect arbuscular mycorrhizal fungal soil communities.

    PubMed

    Lumini, Erica; Vallino, Marta; Alguacil, Maria M; Romani, Marco; Bianciotto, Valeria

    2011-07-01

    Arbuscular mycorrhizal fungi (AMF) comprise one of the main components of soil microbiota in most agroecosystems. These obligate mutualistic symbionts colonize the roots of most plants, including crop plants. Many papers have indicated that different crop management practices could affect AMF communities and their root colonization. However, there is little knowledge available on the influence of conventional and low-input agriculture on root colonization and AMF molecular diversity in rice fields. Two different agroecosystems (continuous conventional high-input rice monocropping and organic farming with a five-year crop rotation) and two different water management regimes have been considered in this study. Both morphological and molecular analyses were performed. The soil mycorrhizal potential, estimated using clover trap cultures, was high and similar in the two agroecosystems. The diversity of the AMF community in the soil, calculated by means of PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and 18S rDNA sequencing on clover trap cultures roots, was higher for the organic cultivation. The rice roots cultivated in the conventional agrosystem or under permanent flooding showed no AMF colonization, while the rice plants grown under the organic agriculture system showed typical mycorrhization patterns. Considered together, our data suggest that a high-input cropping system and conventional flooding depress AMF colonization in rice roots and that organic managements could help maintain a higher diversity of AMF communities in soil. PMID:21830711

  13. Methylmercury Bioaccumulation in Rice and Wetland Biota: employing integrated indices of processes that drive methylmercury risk

    NASA Astrophysics Data System (ADS)

    Eagles-Smith, C.; Ackerman, J.; Windham-Myers, L.; Fleck, J.

    2013-12-01

    Wetlands often are associated with elevated methylmercury (MeHg) production and food web bioaccumulation, making them potentially important sources of Hg to surrounding waters and to wetland-dependent fish and wildlife. However, the cycling of MeHg through wetlands can vary markedly with wetland type. Agricultural wetlands such as rice fields can exhibit particularly pronounced MeHg concentrations and bioaccumulation because their biogeochemical, hydrological, and ecological characteristics facilitate the conversion of inorganic mercury (Hg) to MeHg. Rice fields are characterized by a series of seasonal extreme wetting and drying cycles, sulfate-containing fertilizers, and high levels of labile organic carbon, all of which are key processes in the Hg cycle. Rice fields comprise approximately 20% of freshwater habitats and 11% of cultivated land area globally, providing critical wildlife habitat while offering substantial economic, human health, and ecosystem benefits. Thus, there is strong impetus to better understand the drivers of Hg cycling in rice fields and to develop useful management approaches for minimizing Hg risk associated with rice agriculture without compromising rice production. We examined the role of rice wetlands on MeHg bioaccumulation through foodwebs by employing biosentinel caged fish as integrators of MeHg cycling processes. With experimental field studies in California's Central Valley, we placed biosentinel fishes into nine rice wetlands that were subjected to three different harvest strategies, and into nine managed wetlands that encompassed three different hydrological regimes. We simultaneously measured a suite of biogeochemical processes in surface water, sediment, and pore water in order to link the response in fish Hg bioaccumulation with within-field processes that regulate MeHg cycling. Our preliminary results indicate that fish Hg concentrations were 1.6 times higher in rice wetlands than in managed wetlands. Additionally, fish Hg

  14. [Artificial cultivation modes for Dendrobium officinale].

    PubMed

    Si, Jin-Ping; Yu, Qiao-Xian; Song, Xian-Shui; Shao, Wei-Jiang

    2013-02-01

    Since the beginning of the new century, the artificial cultivation of Dendrobium officinale has made a breakthrough progress. This paper systematically expounds key technologies, main features and cautions of the cultivation modes e.g. bionic-facility cultivation, the original ecological cultivation, and potting cultivation for D. officinale, which can provide useful information for the development and improvement of D. officinale industry. PMID:23713268

  15. On the Possibility of Cultivating Justice through Teaching and Learning: An Argument for Civic Reconciliation in South Africa

    ERIC Educational Resources Information Center

    Waghid, Yusef

    2005-01-01

    In this article the author explores possibilities for cultivating justice with reference to teaching and learning in (South African) universities. It is argued that teachers and learners ought to become responsive, democratic and critical--they need to act justly in order to break with South Africa's apartheid legacy. The author discusses why…

  16. Greenhouse validation of yield component transgressive variation effects of wild Oryza species introgressions in an elite US rice cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of global studies have been conducted which have shown that the wild ancestral species, Oryza rufipogon, possesses beneficial alleles that can be used to improve cultivated rice, O. sativa, for biotic and abiotic stress tolerance as well as yield. Introgression lines (IL) were developed thr...

  17. Water management impacts on arsenic speciation and iron-reducing bacteria in contrasting rice-rhizosphere compartments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice cultivated on arsenic (As) contaminated-soils usually accumulates variable grain-As concentrations, as impacted by genotypic differences, soil variables and crop management. A field-scale experiment was conducted to study the impact of intermittent and continuous flooding on As speciation and m...

  18. Convergent evolution of perenniality in rice and sorghum.

    PubMed

    Hu, F Y; Tao, D Y; Sacks, E; Fu, B Y; Xu, P; Li, J; Yang, Y; McNally, K; Khush, G S; Paterson, A H; Li, Z-K

    2003-04-01

    Annual and perennial habit are two major strategies by which grasses adapt to seasonal environmental change, and these distinguish cultivated cereals from their wild relatives. Rhizomatousness, a key trait contributing to perenniality, was investigated by using an F(2) population from a cross between cultivated rice (Oryza sativa) and its wild relative, Oryza longistaminata. Molecular mapping based on a complete simple sequence-repeat map revealed two dominant-complementary genes controlling rhizomatousness. Rhz3 was mapped to the interval between markers OSR16 [1.3 centimorgans (cM)] and OSR13 (8.1 cM) on rice chromosome 4 and Rhz2 located between RM119 (2.2 cM) and RM273 (7.4 cM) on chromosome 3. Comparative mapping indicated that each gene closely corresponds to major quantitative trait loci (QTLs) controlling rhizomatousness in Sorghum propinquum, a wild relative of cultivated sorghum. Correspondence of these genes in rice and sorghum, which diverged from a common ancestor approximately 50 million years ago, suggests that the two genes may be key regulators of rhizome development in many Poaceae. Many additional QTLs affecting abundance of rhizomes in O. longistaminata were identified, most of which also corresponded to the locations of S. propinquum QTLs. Convergent evolution of independent mutations at, in some cases, corresponding genes may have been responsible for the evolution of annual cereals from perennial wild grasses. DNA markers closely linked to Rhz2 and Rhz3 will facilitate cloning of the genes, which may contribute significantly to our understanding of grass evolution, advance opportunities to develop perennial cereals, and offer insights into environmentally benign weed-control strategies. PMID:12642667

  19. Nitrogen uptake and use efficiency in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a staple food for a large proportion of the world’s population. Most of the rice is produced and consumed in Asia. Rice is produced in both upland and lowland systems, with about 76% of the global rice produced from irrigated-lowland rice systems. Nitrogen (N) is one of the most important in...

  20. Rice disease management under organic production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in organic rice production has increased because of the increased market demand for organic rice. Texas organic rice acreage has constantly increased over the last decade, reaching 32,000 acres in 2012. Texas is now the leading state in organic rice production in the U.S. Organic rice is p...

  1. Organic Rice Production: Challenges and Opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The market demand for organically produced rice has grown steadily with the majority of the acreage now being located in Texas and California. A wide range of organic products are marketed including conventional long and medium grain rice, aromatic or scented rice, rice with colored bran, and rice f...

  2. Determination of fractionation of oxygen isotopes between rice grain and environmental water

    NASA Astrophysics Data System (ADS)

    Kaushal, R.; Ghosh, P.

    2013-12-01

    Oxygen isotopic composition (δ18O) of plant organic matter (POM) serves as a valuable proxy for paleoclimatic studies [1].The δ18O of POM emulates the isotopic composition of the source water [2]. Rice crop cultivation goes back to 12,000 years, when rice was first domesticated in China and the earliest cultivation of rice observed in India was during 3000- 2500 BC. Presently rice is cultivated in many countries around the world including India where the prerequisite of saturated soil water condition for optimum growth of rice crop is provided by the South west monsoons. Earlier studies on δ18O of rice have been limited to its geographic characterization [3]. However, detailed investigations to determine fractionation of oxygen isotopes in water, in different parts of a rice plant, with rice seed organic matter is the primary objective of this work. This is important for understanding the mechanism responsible for the transfer of source water signature to the seed organics and can facilitate understanding of past monsoonal regime using well preserved rice grain remains from archaeological sites. Water from the leaves and culms was extracted by means of heating and cryogenic distillation in a vacuum extraction system [4]. The source water and the water extracted from plant parts were analysed by CO2 equilibration method using Gas Bench peripheral. Rice seed powder, after removal of husk, is composed primarily of starch and were analysed using High Temperature Conversion-Elemental Analyser. Both these peripherals were coupled to an Isotope Ratio Mass spectrometer- MAT253 (Thermo Finnigan). Experimental results discussed here were based on greenhouse and field based studies of water and seed organic composition. The water fed to the plant in the green house showed an average δ18O value of -0.50‰ whereas the field water from irrigation covering the time of grain filling ranges between -1.03‰ and -3.08‰. Figure 1 displays the extent of enrichment recorded in

  3. Estimation of methane and nitrous oxide emissions from rice field with rice straw management in Cambodia.

    PubMed

    Vibol, S; Towprayoon, S

    2010-02-01

    To estimate the greenhouse gas emissions from paddy fields of Cambodia, the methodology of the Intergovernmental Panel on Climate Change (IPCC) guidelines, IPCC coefficients, and emission factors from the experiment in Thailand and another country were used. Total area under rice cultivation during the years 2005-2006 was 2,048,360 ha in the first crop season and 298,529 ha in the second crop season. The emission of methane from stubble incorporation with manure plus fertilizer application areas in the first crop season was estimated to be 192,783.74 ton higher than stubble with manure, stubble with fertilizer, and stubble without fertilizer areas. The fields with stubble burning emitted the highest emission of methane (75,771.29 ton) followed by stubble burning with manure (22,251.08 ton), stubble burning with fertilizer (13,213.27 ton), and stubble burning with fertilizer application areas (3,222.22 ton). The total emission of methane from rice field in Cambodia for the years 2005-2006 was approximately 342,649.26 ton (342.65 Gg) in the first crop season and 36,838.88 ton (36.84 Gg) in the second crop season. During the first crop season in the years 2005-2006, Battambang province emitted the highest amount of CH(4) (38,764.48 ton) and, in the second crop season during the years 2005-2006, the highest emission (8,262.34 ton) was found in Takeo province (8,262.34 ton). Nitrous oxide emission was between 2.70 and 1,047.92 ton in the first crop season and it ranged from 0 to 244.90 ton in the second crop season. Total nitrous oxide emission from paddy rice field was estimated to be 9,026.28 ton in the first crop season and 1,091.93 ton in the second crop season. Larger area under cultivation is responsible for higher emission of methane and nitrous oxide. Total emission of nitrous oxide by using IPCC default emission coefficient was approximately 2,328.85 ton. The total global warming potential of Cambodian paddy rice soil is 11,723,217.03 ton (11,723 Gg

  4. "Niggaz Dyin' Don't Make No News": Exploring the Intellectual Work of an African American Urban Adolescent Boy in an After-School Program

    ERIC Educational Resources Information Center

    Staples, Jeanine M.

    2012-01-01

    In this article, and from the standpoint of an African American woman teacher/researcher, the author explores what happened when one African American adolescent boy known inside of school as a "severely disengaged" student cultivated literacy practices and events of his own volition in an after-school program. The author asks, how does race and…

  5. Exploring Japan through Rice.

    ERIC Educational Resources Information Center

    Wojtan, Linda S.

    1998-01-01

    Explores the role of rice in Japanese culture by presenting historical background and teaching activities in a variety of categories, such as language, sociology, history, and contemporary politics. Suggests teachers create cross-cultural comparisons; for example, the role of corn in the United States. Provides a list of teacher resources. (CMK)

  6. Rice: chemistry and technology.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice has taken center stage this last decade, not only as an important provider of nourishment for the world’s population, but as a grain now recognized as having many unique nutritional and functional attributes with potential to be captured in a multitude of value-added food and non-food applicati...

  7. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled...

  8. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled...

  9. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice... (percent) Removed by a 5 plate 3 (percent) Removed by a 6 plate 3 (percent) Through a 6 sieve 3...

  10. Single-copy gene based 50 K SNP chip for genetic studies and molecular breeding in rice

    PubMed Central

    Singh, Nisha; Jayaswal, Pawan Kumar; Panda, Kabita; Mandal, Paritra; Kumar, Vinod; Singh, Balwant; Mishra, Shefali; Singh, Yashi; Singh, Renu; Rai, Vandna; Gupta, Anita; Raj Sharma, Tilak; Singh, Nagendra Kumar

    2015-01-01

    Single nucleotide polymorphism (SNP) is the most abundant DNA sequence variation present in plant genomes. Here, we report the design and validation of a unique genic-SNP genotyping chip for genetic and evolutionary studies as well as molecular breeding applications in rice. The chip incorporates 50,051 SNPs from 18,980 different genes spanning 12 rice chromosomes, including 3,710 single-copy (SC) genes conserved between wheat and rice, 14,959 SC genes unique to rice, 194 agronomically important cloned rice genes and 117 multi-copy rice genes. Assays with this chip showed high success rate and reproducibility because of the SC gene based array with no sequence redundancy and cross-hybridisation problems. The usefulness of the chip in genetic diversity and phylogenetic studies of cultivated and wild rice germplasm was demonstrated. Furthermore, its efficacy was validated for analysing background recovery in improved mega rice varieties with submergence tolerance developed through marker-assisted backcross breeding. PMID:26111882

  11. Delving deeper into technological innovations to understand differences in rice quality.

    PubMed

    Calingacion, Mariafe; Fang, Lu; Quiatchon-Baeza, Lenie; Mumm, Roland; Riedel, Arthur; Hall, Robert D; Fitzgerald, Melissa

    2015-12-01

    Increasing demand for better quality rice varieties, which are also more suited to growth under sub-optimal cultivation conditions, is driving innovation in rice research. Here we have used a multi-disciplinary approach, involving SNP-based genotyping together with phenotyping based on yield analysis, metabolomic analysis of grain volatiles, and sensory panel analysis to determine differences between two contrasting rice varieties, Apo and IR64. Plants were grown under standard and drought-induced conditions. Results revealed important differences between the volatile profiles of the two rice varieties and we relate these differences to those perceived by the sensory panel. Apo, which is the more drought tolerant variety, was less affected by the drought condition concerning both sensory profile and yield; IR64, which has higher quality but is drought sensitive, showed greater differences in these characteristics in response to the two growth conditions. Metabolomics analyses using GCxGC-MS, followed by multivariate statistical analyses of the data, revealed a number of discriminatory compounds between the varieties, but also effects of the difference in cultivation conditions. Results indicate the complexity of rice volatile profile, even of non-aromatic varieties, and how metabolomics can be used to help link changes in aroma profile with the sensory phenotype. Our outcomes also suggest valuable multi-disciplinary approaches which can be used to help define the aroma profile in rice, and its underlying genetic background, in order to support breeders in the generation of improved rice varieties combining high yield with high quality, and tolerance of both these traits to climate change. PMID:26054242

  12. Rice Glycosyltransferase (GT) Phylogenomic Database

    DOE Data Explorer

    Ronald, Pamela

    The Ronald Laboratory staff at the University of California-Davis has a primary research focus on the genes of the rice plant. They study the role that genetics plays in the way rice plants respond to their environment. They created the Rice GT Database in order to integrate functional genomic information for putative rice Glycosyltransferases (GTs). This database contains information on nearly 800 putative rice GTs (gene models) identified by sequence similarity searches based on the Carbohydrate Active enZymes (CAZy) database. The Rice GT Database provides a platform to display user-selected functional genomic data on a phylogenetic tree. This includes sequence information, mutant line information, expression data, etc. An interactive chromosomal map shows the position of all rice GTs, and links to rice annotation databases are included. The format is intended to "facilitate the comparison of closely related GTs within different families, as well as perform global comparisons between sets of related families." [From http://ricephylogenomics.ucdavis.edu/cellwalls/gt/genInfo.shtml] See also the primary paper discussing this work: Peijian Cao, Laura E. Bartley, Ki-Hong Jung and Pamela C. Ronalda. Construction of a Rice Glycosyltransferase Phylogenomic Database and Identification of Rice-Diverged Glycosyltransferases. Molecular Plant, 2008, 1(5): 858-877.

  13. Real-time and conventional PCR detection of Liberty Link rice varieties and transgenic soy in rice sampled in the Mexican and American retail markets.

    PubMed

    Quirasco, Maricarmen; Schoel, Bernd; Chhalliyil, Pradheep; Fagan, John; Gálvez, Amanda

    2008-10-01

    Samples of rice from Mexican and USA retail stores were analyzed for the presence of transgenic (GM) events using real-time PCR. In screening for the CaMV35S promoter sequence (35SP), positive results were found in 49 and 35% of the Mexican and American samples, respectively. In further investigations in Mexican samples, 43% were positive for P35S::bar, with two above the quantifiable limit; these were 0.07% and 0.05% GMO. Fourteen out of the sixteen positive samples were labeled as imported from the USA. In testing samples bought in American retail shops, 24% showed positive results, all below the quantifiable range. It could be deduced that P35S::bar positive samples were Liberty Link(R) (LL) rice. In distinguishing between LL601 and LL62, end-point PCR was used, corroborating the P35S::bar amplicon length difference of these events. LL62 was found in one rice sample purchased in Mexico and two in the USA samples. Its presence was verified with the 35S terminator sequence. All other LL positive samples contained LL601. None of the samples analyzed showed the presence of Bt63 rice. The LL rice varieties found have been identified as not being commercially cultivated, and so their presence requires further investigation. 35SP was also present in samples which did not have any LL rice. Maize sequences could not be detected in any of the samples; however, soybean DNA was found in Mexican and USA rice samples. The Roundup Ready(R) trait was detected in trace amounts in 16 and 6% of the rice samples bought in Mexico and the USA, respectively. Real-time PCR was shown to be the method of choice for the sensitive and rapid screening of commodities and retail samples for the detection of GM and other contamination. PMID:18668229

  14. African and non-African admixture components in African Americans and an African Caribbean population.

    PubMed

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  15. Seed-Mediated Gene Flow Promotes Genetic Diversity of Weedy Rice within Populations: Implications for Weed Management

    PubMed Central

    He, Zhuoxian; Jiang, Xiaoqi; Ratnasekera, Disna; Grassi, Fabrizio; Perera, Udugahapattuwage; Lu, Bao-Rong

    2014-01-01

    Increased infestation of weedy rice—a noxious agricultural pest has caused significant reduction of grain yield of cultivated rice (Oryza sativa) worldwide. Knowledge on genetic diversity and structure of weedy rice populations will facilitate the design of effective methods to control this weed by tracing its origins and dispersal patterns in a given region. To generate such knowledge, we studied genetic diversity and structure of 21 weedy rice populations from Sri Lanka based on 23 selected microsatellite (SSR) loci. Results indicated an exceptionally high level of within-population genetic diversity (He = 0.62) and limited among-population differentiation (Fst = 0.17) for this predominantly self-pollinating weed. UPGMA analysis showed a loose genetic affinity of the weedy rice populations in relation to their geographical locations, and no obvious genetic structure among populations across the country. This phenomenon was associated with the considerable amount of gene flow between populations. Limited admixture from STRUCTURE analyses suggested a very low level of hybridization (pollen-mediated gene flow) between populations. The abundant within-population genetic diversity coupled with limited population genetic structure and differentiation is likely caused by the considerable seed-mediated gene flow of weedy rice along with the long-distance exchange of farmer-saved rice seeds between weedy-rice contaminated regions in Sri Lanka. In addition to other effective weed management strategies, promoting the application of certified rice seeds with no weedy rice contamination should be the immediate action to significantly reduce the proliferation and infestation of this weed in rice ecosystems in countries with similar rice farming styles as in Sri Lanka. PMID:25436611

  16. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  17. Impacts of sea-level change on human activity at the early Neolithic forager/cultivator site, Kuahuqiao on the east coast of China

    NASA Astrophysics Data System (ADS)

    Zong, Yongqiang; Innes, James; Chen, Zhongyuan; Chen, Chun; Wang, Zhanghua; Wang, Hui

    2010-05-01

    The date and location of the adoption of rice cultivation by foraging cultures in China is of considerable current interest but its understanding is hampered by a lack of information regarding its palaeoenvironmental context. We present detailed multi-proxy palaeoecological research at the earliest-dated site of rice cultivation in the coastal area of east China which has revealed the precise environmental setting of this early Neolithic settlement and its incipient cultivation at c. 7750 cal. BP. Regional and local environmental changes governed the character of the site and the duration of human activity. The rise in relative sea level up to 8000 cal. BP prompted the development of coastal wetland environments at the head of the Hangzhou Bay. A short period of stable sea level allowed natural hydrological succession and terrestrialisation of the site changing from a brackish/freshwater lake to a freshwater marsh/alder carr, which attracted Neolithic foragers to settle and take advantage of the plentiful food resources present in the wetland, wild rice in particular. After a fire clearance of an alder scrub that prepared the ground for settlement, the Kuahuqiao people maintained a reedswamp-type wet grassland in which rice was grown. As relative sea level rose again around 7600-7500 cal. BP, artificial bunding was used to retain nutrient rich water and prevent tidal flooding to provide rice with the consistent water regime it requires. Such bunding resulted in blockage of water which promoted the growth of aquatic plants such as Cattail. Cropping of Cattail stands may have formed part of the subsistence base. Thesite was overwhelmed by marine inundation around 7400-7200 cal. BP as relative sea level rose rapidly for a couple of meters, after which rice cultivation spread to Neolithic sites of Hemudu type elsewhere in the coastal lowlands.

  18. Diversity of the bacterial community in the rice rhizosphere managed under conventional and no-tillage practices.

    PubMed

    Aslam, Zubair; Yasir, Muhammad; Yoon, Hwan Sik; Jeon, Che Ok; Chung, Young Ryun

    2013-12-01

    Bacterial diversity in the rice rhizosphere at different rice growth stages, managed under conventional and no-tillage practices, was explored using a culture-based approach. Actinobacteria are among the bacterial phyla abundant in the rice rhizosphere. Their diversity was further examined by constructing metagenomic libraries based on the 16S rRNA gene, using actinobacterial- and streptomycete-specific polymerase chain reaction (PCR) primers. The study included 132 culturable strains and 125 clones from the 16S rRNA gene libraries. In conventional tillage, there were 38% Proteobacteria, 22% Actinobacteria, 33% Firmicutes, 5% Bacteroidetes, and 2% Acidobacteria, whereas with no-tillage management there were 63% Proteobacteria, 24% Actinobacteria, 6% Firmicutes, and 8% Bacteroidetes as estimated using the culture-dependent method during the four stages of rice cultivation. Principal coordinates analysis was used to cluster the bacterial communities along axes of maximal variance. The different growth stages of rice appeared to influence the rhizosphere bacterial profile for both cultivation practices. Novel clones with low similarities (89-97%) to Actinobacteria and Streptomyces were retrieved from both rice fields by screening the 16S rRNA gene libraries using actinobacterial- and streptomycete-specific primers. By comparing the actinobacterial community retrieved by culture-dependent and molecular methods, it was clear that a more comprehensive assessment of microbial diversity in the rice rhizosphere can be obtained using a combination of both techniques than by using either method alone. We also succeeded in culturing a number of bacteria that were previously described as unculturable. These were in a phylogenetically deep lineage when compared with related cultivable genera. PMID:24385351

  19. Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management.

    PubMed

    An, Ning; Fan, Mingsheng; Zhang, Fusuo; Christie, Peter; Yang, Jianchang; Huang, Jianliang; Guo, Shiwei; Shi, Xiaojun; Tang, Qiyuan; Peng, Jianwei; Zhong, Xuhua; Sun, Yixiang; Lv, Shihua; Jiang, Rongfeng; Dobermann, Achim

    2015-01-01

    Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG) emissions (N2O, CH4 and CO2-equivalent) with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices-BMPs) helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield). Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice system

  20. Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management

    PubMed Central

    An, Ning; Fan, Mingsheng; Zhang, Fusuo; Christie, Peter; Yang, Jianchang; Huang, Jianliang; Guo, Shiwei; Shi, Xiaojun; Tang, Qiyuan; Peng, Jianwei; Zhong, Xuhua; Sun, Yixiang; Lv, Shihua; Jiang, Rongfeng; Dobermann, Achim

    2015-01-01

    Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG) emissions (N2O, CH4 and CO2-equivalent) with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices—BMPs) helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield). Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice system

  1. Suppression of cadmium uptake in rice using fermented bark as a soil amendment.

    PubMed

    Mori, Masanobu; Kotaki, Kenta; Gunji, Fumine; Kubo, Naoyuki; Kobayashi, Shizusa; Ito, Tsukasa; Itabashi, Hideyuki

    2016-04-01

    The contamination of rice paddies with heavy metals has become a serious concern due to their high toxicity to human health. In this study, we developed a chemical-free, fermented bark amendment (FBA) and used it for organic rice cultivation. The application of FBA resulted in the fixation of heavy metals, especially cadmium (Cd), in the soil and suppressed their uptake in brown rice. The suppression of Cd uptake was most effective, since its uptake in rice from FBA-supplemented soil was 10 times lower than that from untreated soil under ordinary water-filling conditions. These results could be explained by the rapid conversion of sulfate ions to sulfide ions, which subsequently react with Cd producing insoluble sulfide species, as well as Cd adsorption to the decomposed bark in soil. The FBA did not affect the uptake of metals, such as calcium and iron, which are necessary for the growth of rice. Thus, the FBA may suppress Cd uptake in rice, and its effectiveness is related to application time and water regime. PMID:26841291

  2. Estimating high mosquito-producing rice fields using spectral and spatial data

    NASA Technical Reports Server (NTRS)

    Wood, B. L.; Beck, L. R.; Washino, R. K.; Hibbard, K. A.; Salute, J. S.

    1992-01-01

    The cultivation of irrigated rice provides ideal larval habitat for a number of anopheline vectors of malaria throughout the world. Anopheles freeborni, a potential vector of human malaria, is associated with the nearly 240,000 hectares of irrigated rice grown annually in Northern and Central California; therefore, this species can serve as a model for the study of rice field anopheline population dynamics. Analysis of field data revealed that rice fields with early season canopy development, that are located near bloodmeal sources (i.e., pastures with livestock) were more likely to produce anopheline larvae than fields with less developed canopies located further from pastures. Remote sensing reflectance measurements of early-season canopy development and geographic information system (GIS) measurements of distanes between rice fields and pastures with livestock were combined to distinguish between high and low mosquito-producing rice fields. Using spectral and distance measures in either a discriminant or Bayesian analysis, the identification of high mosquito-producing fields was made with 85 percent accuracy nearly two months before anopheline larval populations peaked. Since omission errors were also minimized by these approaches, they could provide a new basis for directing abatement techniques for the control of malaria vectors.

  3. Transcriptome Analysis of Early Responsive Genes in Rice during Magnaporthe oryzae Infection.

    PubMed

    Wang, Yiming; Kwon, Soon Jae; Wu, Jingni; Choi, Jaeyoung; Lee, Yong-Hwan; Agrawal, Ganesh Kumar; Tamogami, Shigeru; Rakwal, Randeep; Park, Sang-Ryeol; Kim, Beom-Gi; Jung, Ki-Hong; Kang, Kyu Young; Kim, Sang Gon; Kim, Sun Tae

    2014-12-01

    Rice blast disease caused by Magnaporthe oryzae is one of the most serious diseases of cultivated rice (Oryza sativa L.) in most rice-growing regions of the world. In order to investigate early response genes in rice, we utilized the transcriptome analysis approach using a 300 K tilling microarray to rice leaves infected with compatible and incompatible M. oryzae strains. Prior to the microarray experiment, total RNA was validated by measuring the differential expression of rice defense-related marker genes (chitinase 2, barwin, PBZ1, and PR-10) by RT-PCR, and phytoalexins (sakuranetin and momilactone A) with HPLC. Microarray analysis revealed that 231 genes were up-regulated (>2 fold change, p < 0.05) in the incompatible interaction compared to the compatible one. Highly expressed genes were functionally characterized into metabolic processes and oxidation-reduction categories. The oxidative stress response was induced in both early and later infection stages. Biotic stress overview from MapMan analysis revealed that the phytohormone ethylene as well as signaling molecules jasmonic acid and salicylic acid is important for defense gene regulation. WRKY and Myb transcription factors were also involved in signal transduction processes. Additionally, receptor-like kinases were more likely associated with the defense response, and their expression patterns were validated by RT-PCR. Our results suggest that candidate genes, including receptor-like protein kinases, may play a key role in disease resistance against M. oryzae attack. PMID:25506299

  4. Effect of cerium oxide nanoparticles on the quality of rice ( Oryza sativa L.) grains.

    PubMed

    Rico, Cyren M; Morales, Maria Isabel; Barrios, Ana Cecilia; McCreary, Ricardo; Hong, Jie; Lee, Wen-Yee; Nunez, Jose; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2013-11-27

    Despite the remarkable number of publications on the interaction of engineered nanoparticles (ENPs) with plants, knowledge of the implications of ENPs in the nutritional value of food crops is still limited. This research was performed to study the quality of rice grains harvested from plants grown in soil treated with cerium oxide nanoparticles (nCeO2). Three rice varieties (high, medium, and low amylose) were cultivated to full maturity in soil amended with nCeO2 at 0 and 500 mg kg(-1) soil. Ce accumulation, nutrient content, antioxidant property, and nutritional quality of the rice grains were evaluated. Results showed that rice grains from nCeO2-treated plants had less Fe, S, prolamin, glutelin, lauric and valeric acids, and starch. Moreover, the nCeO2 reduced in grains all antioxidant values, except flavonoids. Medium- and low-amylose varieties accumulated more Ce in grains than the high-amylose variety, but the grain quality of the medium-amylose variety showed higher sensitivity to the nCeO2 treatment. These results indicate that nCeO2 could compromise the quality of rice. To the authors' knowledge, this is the first report on the effects nCeO2 on rice grain quality. PMID:24188281

  5. The Birth of a Black Rice Gene and Its Local Spread by Introgression

    PubMed Central

    Oikawa, Tetsuo; Maeda, Hiroaki; Oguchi, Taichi; Yamaguchi, Takuya; Tanabe, Noriko; Ebana, Kaworu; Yano, Masahiro; Izawa, Takeshi

    2015-01-01

    The origin and spread of novel agronomic traits during crop domestication are complex events in plant evolution. Wild rice (Oryza rufipogon) has red grains due to the accumulation of proanthocyanidins, whereas most cultivated rice (Oryza sativa) varieties have white grains induced by a defective allele in the Rc basic helix-loop-helix (bHLH) gene. Although the events surrounding the origin and spread of black rice traits remain unknown, varieties with black grains due to anthocyanin accumulation are distributed in various locations throughout Asia. Here, we show that the black grain trait originated from ectopic expression of the Kala4 bHLH gene due to rearrangement in the promoter region. Both the Rc and Kala4 genes activate upstream flavonol biosynthesis genes, such as chalcone synthase and dihydroflavonol-4-reductase, and downstream genes, such as leucoanthocyanidin reductase and leucoanthocyanidin dioxygenase, to produce the respective specific pigments. Genome analysis of 21 black rice varieties as well as red- and white-grained landraces demonstrated that black rice arose in tropical japonica and its subsequent spread to the indica subspecies can be attributed to the causal alleles of Kala4. The relatively small size of genomic fragments of tropical japonica origin in some indica varieties indicates that refined introgression must have occurred by natural crossbreeding in the course of evolution of the black trait in rice. PMID:26362607

  6. Growth, yield and elemental status of rice (Oryza sativa) grown in fly ash amended soils.

    PubMed

    Mishra, Mamata; Sahu, Rajani K; Padhy, Rabindra N

    2007-03-01

    Fly ash (FA) from coal in Orissa (India) was used for amending soil at levels equivalent to 0, 1, 2.5, 5, 10 and 15 metric tons per ha in which, rice was grown and elemental residues of amended soil and plant parts were enumerated. FA amendments caused significant improvement in soil quality and germination percentage of rice seeds. Growth (shoot length, leaf area and pigment composition) and yield (panicle length, seeds per panicle, seed weight and yield per plant) of rice increased with an increase in FA amendments. Catalase and peroxidase activities of young leaves increased initially in plants cultivated at lower FA levels but declined sharply at higher FA levels while the protein content of seeds improved at higher FA levels. Sodium content of rice-roots did not change with FA amendments but the contents of K, P, Mn, Ni, Co, Pb, Zn, Cu, Cr, and Cd showed a progressive increase. Seeds of plants grown in FA amended soils accumulated Cu, Pb, Cr and Cd in amounts below allowable limits. Based on the data obtained we found that flooded-rice soil amended at 10 metric tons FA per ha level of FA not only improved the physical properties of the soil but also contributed to better growth and yield of rice. PMID:17253160

  7. Integrating cultivation history into EBIPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecologically based invasive plant management (EBIPM) is a systematic thinking and planning process to assist with applying the appropriate combination of tools and strategies to addrress the underlying cause of invasion rather than simply controlling invasive annual grass abundance. Cultivation his...

  8. Cultivating Spontaneous Self-Discipline.

    ERIC Educational Resources Information Center

    O'Shaughnessy, Molly

    1998-01-01

    Draws on contemporary sources to provide strategies for cultivating self-discipline. Advocates self-healing for the adult to be free from destructive attitudes and personal history that can keep adults from being mindful of the child's needs, perspective, and potential. Concludes with ways to facilitate a truly Montessori approach to discipline.…

  9. Cultivating Spiritual Reflectivity in Teachers.

    ERIC Educational Resources Information Center

    Mayes, Clifford

    2001-01-01

    Discusses the need to address spiritual beliefs in teacher education, arguing that: because spiritual impulses are so primary for many people, they must be addressed in teacher education; educators must recognize and cultivate students' spiritual motivations to teach and foster reflectivity; and student teachers must learn what they can legally…

  10. Rice: The First Crop Genome.

    PubMed

    Jackson, Scott A

    2016-12-01

    Rice was the first sequenced crop genome, paving the way for the sequencing of additional and more complicated crop genomes. The impact that the genome sequence made on rice genetics and breeding research was immediate, as evidence by citations and DNA marker use. The impact on other crop genomes was evident too, particularly for those within the grass family. As we celebrate 10 years since the completion of the rice genome sequence, we look forward to new empowering tool sets that will further revolutionize research in rice genetics and breeding and result in varieties that will continue to feed a growing population. PMID:27003180

  11. Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein.

    PubMed

    2006-01-01

    This report addresses the safety of cosmetic ingredients derived from rice, Oryza sativa. Oils, Fatty Acids, and Waxes: Rice Bran Oil functions in cosmetics as a conditioning agent--occlusive in 39 formulations across a wide range of product types. Rice Germ Oil is a skin-conditioning agent--occlusive in six formulations in only four product categories. Rice Bran Acid is described as a surfactant-cleansing agent, but was not in current use. Rice Bran Wax is a skin-conditioning agent--occlusive in eight formulations in five product categories. Industry did not directly report any use of Rice Bran Wax. Hydrogenated Rice Bran Wax is a binder, skin-conditioning agent--occlusive, and viscosity-increasing agent--nonaqueous in 11 formulations in six product categories. Rice Bran Oil had an oral LD50 of > 5 g/kg in white rats and Rice Wax had an oral LD50 of > 24 g/kg in male mice. A three-generation oral dosing study reported no toxic or teratologic effects in albino rats fed 10% Rice Bran Oil compared to a control group fed Peanut Oil. Undiluted Rice Bran Oil, Rice Germ Oil, and Hydrogenated Rice Bran Wax were not irritants in animal skin tests. Rice Bran Oil was not a sensitizer. Rice Bran Oil, Rice Germ Oil, Rice Wax, and Hydrogenated Rice Bran Wax were negative in ocular toxicity assays. A mixture of Rice Bran Oil and Rice Germ Oil had a ultraviolet (UV) absorption maximum at 315 nm, but was not phototoxic in a dermal exposure assay. Rice Bran Oil was negative in an Ames assay, and a component, gamma-oryzanol, was negative in bacterial and mammalian mutagenicity assays. Rice oils, fatty acids, and waxes were, at most, mildly irritating in clinical studies. Extracts: Rice Bran Extract is used in six formulations in four product categories. Rice Extract is a hair-conditioning agent, but was not in current use. Hydrolyzed Rice Extract is used in four formulations and current concentration of use data were provided for other uses. Hydrolyzed Rice Bran Extract, described

  12. Analysis of Active Components and Proteomics of Chinese Wild Rice (Zizania latifolia (Griseb) Turcz) and Indica Rice (Nagina22).

    PubMed

    Jiang, Ming-Xia; Zhai, Li-Jie; Yang, Hua; Zhai, Shu-Menghui; Zhai, Cheng-Kai

    2016-08-01

    The ancient Chinese wild rice (Zizania latifolia (Griseb) Turcz) (CWR) has valuable biological and medicinal functions. To assess the advantages lost in modern cultivated rice after domestication, we compared the composition of bioactive compounds and the results of proteomic analysis with those of Indica rice (N22). We used routine methods to determine the protein, total dietary fiber, amino acid, mineral substance, plant secondary metabolites, and amino acid composition of CWR and N22. The protein and mineral contents of CWR were two times that of N22, and the levels of calcium, potassium, magnesium, chromium, iron, and zinc were significantly higher than those of N22 (P < .05). There was ∼7.6 times more dietary fiber in CWR than in N22, but fewer carbohydrates (P < .05). Anthocyanins and chlorophyll were detected in CWR, but were absent from N22. Compared with N22, CWR had 53, 19, and 5.4 times higher (P < .05) levels of saponins, flavonoids, and plant sterols, respectively. The amino acid score of CWR was 66.6, which was significantly higher than N22. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that the main seed proteins of CWR were glutelins, including both acid and alkaline subunits, which were approximately twice those of N22. To investigate the differences in protein profiles between CWR and N22, we conducted two-dimensional electrophoresis (2-DE) analysis of the total proteins in the seeds of the two rice species. 2-DE gels revealed 19 differentially expressed proteins. Information obtained from peptide mass fingerprinting indicates that glutelin precursor caffeoyl coenzyme A (CoA) O-methyltransferase and putative bithoraxoid-like protein can provide good gene sources for improving rice quality. PMID:27533651

  13. 16 Extraordinary African Americans.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    This collection for children tells the stories of 16 African Americans who helped make America what it is today. African Americans can take pride in the heritage of these contributors to society. Biographies are given for the following: (1) Sojourner Truth, preacher and abolitionist; (2) Frederick Douglass, abolitionist; (3) Harriet Tubman, leader…

  14. African Studies Computer Resources.

    ERIC Educational Resources Information Center

    Kuntz, Patricia S.

    African studies computer resources that are readily available in the United States with linkages to Africa are described, highlighting those most directly corresponding to African content. Africanists can use the following four fundamental computer systems: (1) Internet/Bitnet; (2) Fidonet; (3) Usenet; and (4) dial-up bulletin board services. The…

  15. African Literature as Celebration.

    ERIC Educational Resources Information Center

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and dignity. (AF)

  16. Educating African American Males

    ERIC Educational Resources Information Center

    Bell, Edward E.

    2010-01-01

    Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

  17. Africans Away from Home.

    ERIC Educational Resources Information Center

    Clarke, John Henrik

    Africans who were brought across the Atlantic as slaves never fully adjusted to slavery or accepted its inevitability. Resistance began on board the slave ships, where many jumped overboard or committed suicide. African slaves in South America led the first revolts against tyranny in the New World. The first slave revolt in the Caribbean occurred…

  18. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  19. Diabetes in African Americans

    PubMed Central

    Marshall, M

    2005-01-01

    African Americans have a high risk for type 2 diabetes. Genetic traits, the prevalence of obesity, and insulin resistance all contribute to the risk of diabetes in the African American community. African Americans have a high rate of diabetic complications, because of poor glycaemic control and racial disparities in health care in the USA. African Americans with diabetes may have an atypical presentation that simulates type 1 diabetes, but then their subsequent clinical course is typical of type 2 diabetes. Culturally sensitive strategies, structured disease management protocols, and the assistance of nurses, diabetic educators, and other health care professionals are effective in improving the outcome of diabetes in the African American community. PMID:16344294

  20. African bees to control African elephants

    NASA Astrophysics Data System (ADS)

    Vollrath, Fritz; Douglas-Hamilton, Iain

    2002-11-01

    Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

  1. Rice bacterial endophytes: isolation of a collection, identification of beneficial strains and microbiome analysis.

    PubMed

    Bertani, Iris; Abbruscato, Pamela; Piffanelli, Pietro; Subramoni, Sujatha; Venturi, Vittorio

    2016-06-01

    Endophytes are harmless or beneficial microorganisms that live inside plants between cells. The relationship they develop with the plant as well as their potential role in plant health is at large unexplored and it is believed that the opportunity to find new and interesting endophytes among the large variety of plants is great. Here, we present the isolation and analysis of a large collection of endophytes from one cultivar of rice grown in Italy. A total 1318 putative endophytes were isolated from roots, leaves and stems from rice grown in submerged and dry conditions and a working collection of 229 isolates was created. Among these, several isolates were confirmed to be endophytes and a few displayed the trait of plant growth promotion. A cultivation independent analysis via 16S rDNA amplicons of the bacterial community of the endosphere was also performed providing information on bacterial diversity in the rice endopshere. PMID:27038229

  2. Delay-tolerant mobile network protocol for rice field monitoring using wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Guitton, Alexandre; Andres, Frédéric; Cardoso, Jarbas Lopes; Kawtrakul, Asanee; Barbin, Silvio E.

    2015-10-01

    The monitoring of rice fields can improve productivity by helping farmers throughout the rice cultivation cycle, on various issues: when to harvest, when to treat the crops against disease, when to increase the water level, how to share observations and decisions made in a collaborative way, etc. In this paper, we propose an architecture to monitor a rice field by a wireless sensor network. Our architecture is based on static sensor nodes forming a disconnected network, and mobile nodes communicating with the sensor nodes in a delay-tolerant manner. The data collected by the static sensor nodes are transmitted to mobile nodes, which in turn transmit them to a gateway, connected to a database, for further analysis. We focus on the related architecture, as well as on the energy-efficient protocols intended to perform the data collection.

  3. Sustainable reuse of rice residues as feedstocks in vermicomposting for organic fertilizer production.

    PubMed

    Shak, Katrina Pui Yee; Wu, Ta Yeong; Lim, Su Lin; Lee, Chieh Ai

    2014-01-01

    Over the past decade, rice (Oryza sativa or Oryza glaberrima) cultivation has increased in many rice-growing countries due to the increasing export demand and population growth and led to a copious amount of rice residues, consisting mainly of rice straw (RS) and rice husk (RH), being generated during and after harvesting. In this study, Eudrilus eugeniae was used to decompose rice residues alone and rice residues amended with cow dung (CD) for bio-transformation of wastes into organic fertilizer. Generally, the final vermicomposts showed increases in macronutrients, namely, calcium (11.4-34.2%), magnesium (1.3-40.8%), phosphorus (1.2-57.3%), and potassium (1.1-345.6%) and a decrease in C/N ratio (26.8-80.0%) as well as increases in heavy metal content for iron (17-108%), copper (14-120%), and manganese (6-60%) after 60 days of vermicomposting. RS as a feedstock was observed to support healthier growth and reproduction of earthworms as compared to RH, with maximum adult worm biomass of 0.66 g/worm (RS) at 60 days, 31 cocoons (1RS:2CD), and 23 hatchlings (1RS:1CD). Vermicomposting of RS yielded better results than RH among all of the treatments investigated. RS that was mixed with two parts of CD (1RS:2CD) showed the best combination of nutrient results as well as the growth of E. eugeniae. In conclusion, vermicomposting could be used as a green technology to bio-convert rice residues into nutrient-rich organic fertilizers if the residues are mixed with CD in the appropriate ratio. PMID:23900949

  4. Evaluating the Effect of Expressing a Peanut Resveratrol Synthase Gene in Rice.

    PubMed

    Zheng, Shigang; Zhao, Shanchang; Li, Zhen; Wang, Qingguo; Yao, Fangyin; Yang, Lianqun; Pan, Jiaowen; Liu, Wei

    2015-01-01

    Resveratrol (Res) is a type of natural plant stilbenes and phytoalexins that only exists in a few plant species. Studies have shown that the Res could be biosynthesized and accumulated within plants, once the complete metabolic pathway and related enzymes, such as the key enzyme resveratrol synthase (RS), existed. In this study, a RS gene named PNRS1 was cloned from the peanut, and the activity was confirmed in E. coli. Using transgenic approach, the PNRS1 transgenic rice was obtained. In T3 generation, the Res production and accumulation were further detected by HPLC. Our data revealed that compared to the wild type rice which trans-resveratrol was undetectable, in transgenic rice, the trans-resveratrol could be synthesized and achieved up to 0.697 μg/g FW in seedlings and 3.053 μg/g DW in seeds. Furthermore, the concentration of trans-resveratrol in transgenic rice seedlings could be induced up to eight or four-fold higher by ultraviolet (UV-C) or dark, respectively. Simultaneously, the endogenous increased of Res also showed the advantages in protecting the host plant from UV-C caused damage or dark-induced senescence. Our data indicated that Res was involved in host-defense responses against environmental stresses in transgenic rice. Here the results describes the processes of a peanut resveratrol synthase gene transformed into rice, and the detection of trans-resveratrol in transgenic rice, and the role of trans-resveratrol as a phytoalexin in transgenic rice when treated by UV-C and dark. These findings present new outcomes of transgenic approaches for functional genes and their corresponding physiological functions, and shed some light on broadening available resources of Res, nutritional improvement of crops, and new variety cultivation by genetic engineering. PMID:26302213

  5. Sea level rise impacts on rice production: The Ebro Delta as an example.

    PubMed

    Genua-Olmedo, Ana; Alcaraz, Carles; Caiola, Nuno; Ibáñez, Carles

    2016-11-15

    Climate change and sea level rise (SLR) are global impacts threatening the sustainability of coastal territories and valuable ecosystems such as deltas. The Ebro Delta is representative of the vulnerability of coastal areas to SLR. Rice cultivation is the main economic activity in the region. Rice fields occupy most of the delta (ca. 65%) and are vulnerable to accelerated SLR and consequent increase in soil salinity, the most important physical factor affecting rice production. We developed a model to predict the impacts of SLR on soil salinity and rice production under different scenarios predicted by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change by coupling data from Geographic Information Systems with Generalized Linear Models. Soil salinity data were measured in agricultural parcels and rice production from surveys among farmers. The correlation between observed and soil salinity predicted values was high and significant (Pearson's r=0.72, P<0.0001), thus supporting the predictive ability of the model. Soil salinity was directly related to distances to the river, to the delta inner border, and to the river old mouth, while clay presence, winter river flow and surface elevation were inversely related to it. Surface elevation was the most important variable in explaining soil salinity. Rice production was negatively influenced by soil salinity, thus the models predict a decrease from higher elevation zones close to the river to the shoreline. The model predicts a maximum reduction in normalized rice production index from 61.2% in 2010 to 33.8% by 2100 in the worst considered scenario (SLR=1.8m), with a decrease of profit up to 300 € per hectare. The model can be applied to other deltaic areas worldwide, and help rice farmers and stakeholders to identify the most vulnerable areas to SLR impacts. PMID:27481453

  6. Evaluating the Effect of Expressing a Peanut Resveratrol Synthase Gene in Rice

    PubMed Central

    Li, Zhen; Wang, Qingguo; Yao, Fangyin; Yang, Lianqun; Pan, Jiaowen; Liu, Wei

    2015-01-01

    Resveratrol (Res) is a type of natural plant stilbenes and phytoalexins that only exists in a few plant species. Studies have shown that the Res could be biosynthesized and accumulated within plants, once the complete metabolic pathway and related enzymes, such as the key enzyme resveratrol synthase (RS), existed. In this study, a RS gene named PNRS1 was cloned from the peanut, and the activity was confirmed in E. coli. Using transgenic approach, the PNRS1 transgenic rice was obtained. In T3 generation, the Res production and accumulation were further detected by HPLC. Our data revealed that compared to the wild type rice which trans-resveratrol was undetectable, in transgenic rice, the trans-resveratrol could be synthesized and achieved up to 0.697 μg/g FW in seedlings and 3.053 μg/g DW in seeds. Furthermore, the concentration of trans-resveratrol in transgenic rice seedlings could be induced up to eight or four-fold higher by ultraviolet (UV-C) or dark, respectively. Simultaneously, the endogenous increased of Res also showed the advantages in protecting the host plant from UV-C caused damage or dark-induced senescence. Our data indicated that Res was involved in host-defense responses against environmental stresses in transgenic rice. Here the results describes the processes of a peanut resveratrol synthase gene transformed into rice, and the detection of trans-resveratrol in transgenic rice, and the role of trans-resveratrol as a phytoalexin in transgenic rice when treated by UV-C and dark. These findings present new outcomes of transgenic approaches for functional genes and their corresponding physiological functions, and shed some light on broadening available resources of Res, nutritional improvement of crops, and new variety cultivation by genetic engineering. PMID:26302213

  7. The Challenges and Solutions for Cadmium-contaminated Rice in China: A Critical Review.

    PubMed

    Hu, Yuanan; Cheng, Hefa; Tao, Shu

    2016-01-01

    The wide occurrence of Cd-contaminated rice in southern China poses significant public health risk and deserves immediate action, which arises primarily from extensive metal (including Cd) contamination of paddies with the fast expansion of nonferrous metal mining and smelting activities. Accumulation of Cd in rice grains can be reduced by removing Cd from the contaminated paddy soils, reducing its bioavailability, and controlling its uptake by rice plants. Although a range of measures can be taken to rehabilitate Cd-contaminated lands, including soil replacement and turnover, chemical washing, and phytoremediation, they are either too expensive and/or too slow. Various amendment materials, including lime, animal manures, and biochar, can be used to immobilize Cd in soils, but such fixation approach can only temporarily reduce Cd availability to rice uptake. Cultivation of alternative crops with low Cd accumulation in edible plant parts is impractical on large scales due to extensive contamination and food security concerns in southern China. Transgenic techniques can help develop rice cultivars with low Cd accumulation in grains, but little public acceptance is expected for such products. As an alternative, selection and development of low-Cd rice varieties and hybrids through plant biotechnology and breeding, particularly, by integration of marker-assisted selection (MAS) with traditional breeding, could be a practical and acceptable option that would allow continued rice production in soils with high bioavailability of Cd. Plant biotechnology and breeding can also help develop Cd-hyperaccumulating rice varieties, which can greatly facilitate phytoremediation of contaminated paddies. To eliminate the long-term risk of Cd entering the food chain, soils contaminated by Cd should be cleaned up when cost-effective remediation measures are available. PMID:27179698

  8. Outcrossing Potential between U.S. Blackhull Red Rice and Indica Rice Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy red rice is a major weed pest of rice in the southern U.S. Outcrossing between red rice and commercial tropical japonica rice cultivars has resulted in new weed biotypes that further hinder the effectiveness of weed management. In recent years, indica rice has been used increasingly as a ger...

  9. A comparative study on carbon footprint of rice production between household and aggregated farms from Jiangxi, China.

    PubMed

    Yan, Ming; Luo, Ting; Bian, Rongjun; Cheng, Kun; Pan, Genxing; Rees, Robert

    2015-06-01

    Quantifying the carbon footprint (CF) for crop production can help identify key options to mitigate greenhouse gas (GHG) emissions in agriculture. In the present study, both household and aggregated farm scales were surveyed to obtain the data of rice production and farming management practices in a typical rice cultivation area of Northern Jiangxi, China. The CFs of the different rice systems including early rice, late rice, and single rice under household and aggregated farm scale were calculated. In general, early rice had the lower CF in terms of land use and grain production being 4.54 ± 0.44 t CO2-eq./ha and 0.62 ± 0.1 t CO2-eq./t grain than single rice (6.84 ± 0.79 t CO2-eq./ha and 0.80 ± 0.13 t CO2-eq./t grain) and late rice (8.72 ± 0.54 t CO2-eq./ha and 1.1 ± 0.17 t CO2-eq./t grain). The emissions from nitrogen fertilizer use accounted for 33 % of the total CF on average and the direct CH4 emissions for 57 %. The results indicated that the CF of double rice cropping under aggregated farm being 0.86 ± 0.11 t CO2-eq./t grain was lower by 25 % than that being 1.14 ± 0.25 t CO2-eq./t grain under household farm, mainly due to high nitrogen use efficiency and low methane emissions. Therefore, developing the aggregated farm scale with efficient use of agro-chemicals and farming operation for greater profitability could offer a strategy for reducing GHG emissions in China's agriculture. PMID:25947895

  10. Update on organic rice research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic products command a premium in the marketplace and bring greater farmgate value to growers and processors. Although total rice acreage has decreased in Texas over the last ten years, there has been an increase in rice acreage produced under organic management. USDA ARS has conducted research ...

  11. Remote Sensing Based Methane Emission Inventory Vis-A-Vis Rice Cultural Types Of South Asia

    NASA Astrophysics Data System (ADS)

    Manjunath, K. R.; More, R.; Chauhan, P.; Vyas, A.; Panigrahy, S.; Parihar, J. S.

    2014-11-01

    Rice cultivation has been recognized as one of the major anthropogenic source for methane (CH4) emissions which is a microbial mediated anaerobic activity, mainly favoured by the flooded conditions in the rice fields. Information available on CH4 emission is limited, especially in a spatial domain, mainly because of the complexity involved in generating such data. The current approach demonstrates the use of secondary data sources available on the methane emission scaling factors, coupled with the information derived on rice cultural types and crop calendar. Methane emission from each type of rice field was firstly calculated by multiplying the emission factor by the corresponding cultivation area and length of cropping period. The values were then extrapolated over each country with respect to the rice area and crop duration for under each cultural type. The rice cultural type wise methane emission value for South Asia was derived by summation of individual emission values for the respective cultural type within each country. The total methane emission derived for South Asia region is (4.7817 Tg/yr). The mean methane emission estimates derived for each country are viz. India (3.3860 Tg/yr), Bangladesh (0.9136 Tg/yr), Pakistan (0.2675 Tg/yr), Sri Lanka (0.1073 Tg/yr) and Nepal (0.1074 Tg/yr). The derived methane emission estimates could be used to study the regional variations within the country and also to adopt the mitigation strategies to combat the high methane emission values within specific cultural type by means of altering the farming practise or water regime.

  12. Mitigation options for methane emissions from rice fields in the Philippines

    SciTech Connect

    Lantin, R.S.; Buendia, L.V.; Wassmann, R.

    1996-12-31

    The contribution of Philippine rice production to global methane emission and breakthroughs in methane emission studies conducted in the country are presented in this paper. A significant impact in the reduction of GHG emissions from agriculture can be achieved if methane emissions from ricefields can be abated. This study presents the contribution of Philippine rice cultivation to global methane emission and breakthroughs in methane emission studies in the country which address the issue of mitigation. Using the derived emission factors from local measurements, rice cultivation contributes 566.6 Gg of methane emission in the Philippines. This value is 62% of the total methane emitted from the agriculture sector. The emission factors employed which are 78% of the IPCC value for irrigated rice and 95% for rainfed rice were derived from measurements with an automatic system taken during the growth duration in the respective ecosystems. Plots drained for 2 weeks at midtillering and before harvest gave a significant reduction in methane emission as opposed to continuously flooded plots and plots drained before harvest. The cultivar Magat reduced methane emission by 50% as compared to the check variety IR72. The application of ammonium sulfate instead of urea reduced methane emission by 10% to 34%. Addition of 6 t ha{sup {minus}1} phosphogypsum in combination with urea reduced emission by 74% as opposed to plots applied with urea alone. It is also from the results of such measurements that abatement strategies are based as regards to modifying treatments such as water management, fertilization, and choice of rice variety. It is not easy to identify and recommend mitigation strategies that will fit a particular cropping system. However, the identified mitigation options provide focus for the abatement of methane emission from ricefields.

  13. Spot-5 multispectral image for 60-75 days of rice mapping

    NASA Astrophysics Data System (ADS)

    Amiruddin Ramli, Mohd; Shariff, Abdul Rashid Mohamed; Khairunniza Bejo, Siti

    2014-06-01

    The objective of this study is to investigate the potential application of Spot-5 multispectral satellite data in monitoring rice cultivation areas in IADA (Integrated Agriculture Development Area) located at Kerian District, Perak Malaysia. Information of the rice cultivation areas is a global economic and environmental significance. Multi-spectral images acquired at high spatial resolution are an important tool, especially in agricultural applications. This paper addresses the relationship between normalize difference vegetation index (NDVI) and ancillary data acquired from Farmers Organization Authority (PPK) for 217 farmer's field in IADA Kerian. The results indicated that NDVI range 0.62 - 0.75 has a strong positive relationship with the ground survey area estimation with (r = 0.85; p <0.01) (r2 = 0.722). The r2 value of 0.722 indicated a statistically significant linear relationship between the rice area estimate using NDVI range 0.62 - 0.75 and on the ground surveyed data for 217 farmers' fields. The equation of unstandardized distribution can be described as Ŷ=0.0197+0.852x. The equation for standardized regression formula for this distribution is Ŷ= 0.850x. Thus, the results indicate that 60-75 days of rice area can be estimated from the following equation Ŷ=0.197+0.852x, where Ŷ is the predicted rice area and x is area calculated using NDVI range 0.62-0.75 in IADA Kerian Perak Malaysia. The results appear promising and rice mapping operations using SPOT-5 multispectral image data can be foreseen.

  14. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests

    PubMed Central

    Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

    2008-01-01

    Background Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which ~21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Results Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. Conclusion In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high

  15. 75 FR 56911 - Request for Public Comment on the United States Standards for Rough Rice, Brown Rice for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ..., Brown Rice for Processing, and Milled Rice standards were last revised in 1993 (58 FR 68015) and appear... technology used to harvest, process, and test rice; and also rice marketing. To ensure that standards and... learn more about Rough Rice, Brown Rice for Processing, and Milled Rice standardization and...

  16. Epigenetic Inheritance in Rice Plants

    PubMed Central

    Akimoto, Keiko; Katakami, Hatsue; Kim, Hyun-Jung; Ogawa, Emiko; Sano, Cecile M.; Wada, Yuko; Sano, Hiroshi

    2007-01-01

    Background and Aims Epigenetics is defined as mechanisms that regulate gene expression without base sequence alteration. One molecular basis is considered to be DNA cytosine methylation, which reversibly modifies DNA or chromatin structures. Although its correlation with epigenetic inheritance over generations has been circumstantially shown, evidence at the gene level has been limited. The present study aims to find genes whose methylation status directly correlates with inheritance of phenotypic changes. Methods DNA methylation in vivo was artificially reduced by treating rice (Oryza sativa ssp. japonica) seeds with 5-azadeoxycytidine, and the progeny were cultivated in the field for > 10 years. Genomic regions with changed methylation status were screened by the methylation-sensitive amplified polymorphysm (MSAP) method, and cytosine methylation was directly scanned by the bisulfite mapping method. Pathogen infection with Xanthomonas oryzae pv. oryzae, race PR2 was performed by the scissors-dip method on mature leaf blades. Key Results The majority of seedlings were lethal, but some survived to maturity. One line designated as Line-2 showed a clear marker phenotype of dwarfism, which was stably inherited by the progeny over nine generations. MSAP screening identified six fragments, among which two were further characterized by DNA blot hybridization and direct methylation mapping. One clone encoding a retrotransposon gag–pol polyprotein showed a complete erasure of 5-methylcytosines in Line-2, but neither translocation nor expression of this region was detectable. The other clone encoded an Xa21-like protein, Xa21G. In wild-type plants, all cytosines were methylated within the promoter region, whereas in Line-2, corresponding methylation was completely erased throughout generations. Expression of Xa21G was not detectable in wild type but was constitutive in Line-2. When infected with X. oryzae pv. oryzae, against which Xa21 confers resistance in a gene

  17. Fitness correlates of crop transgene flow into weedy populations: a case study of weedy rice in China and other examples.

    PubMed

    Lu, Bao-Rong; Yang, Xiao; Ellstrand, Norman C

    2016-08-01

    Whether transgene flow from crops to cross-compatible weedy relatives will result in negative environmental consequences has been the topic of discussion for decades. An important component of environmental risk assessment depends on whether an introgressed transgene is associated with a fitness change in weedy populations. Several crop-weed pairs have received experimental attention. Perhaps, the most worrisome example is transgene flow from genetically engineered cultivated rice, a staple for billions globally, to its conspecific weed, weedy rice. China's cultivated/weedy rice system is one of the best experimentally studied systems under field conditions for assessing how the presence of transgenes alters the weed's fitness and the likely impacts of that fitness change. Here, we present the cultivated/weedy rice system as a case study on the consequences of introgressed transgenes in unmanaged populations. The experimental work on this system reveals considerable variation in fitness outcomes - increased, decreased, and none - based on the transgenic trait, its introgressed genomic background, and the environment. A review of similar research from a sample of other crop-wild pairs suggests such variation is the rule. We conclude such variation in fitness correlates supports the case-by-case method of biosafety regulation is sound. PMID:27468304

  18. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    PubMed Central

    He, Haibing; Yang, Ru; Jia, Biao; Chen, Lin; Fan, Hua; Cui, Jing; Yang, Dong; Li, Menglong; Ma, Fu-Yu

    2014-01-01

    Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM), furrow irrigation with nonmulching (FIN), and drip irrigation with plastic mulching (DI). Compared with the conventional flooding (CF) treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN), lower maximum quantum yield (Fv/Fm), and lower effective quantum yield of PSII photochemistry (ΦPSII). And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC). Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA) were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation. PMID:24741364

  19. Trapping efficiencies of cultivated and natural riparian vegetation of northern Laos.

    PubMed

    Vigiak, Olga; Ribolzi, Olivier; Pierret, Alain; Sengtaheuanghoung, Oloth; Valentin, Christian

    2008-01-01

    In northern Laos, intensification of cultivation on sloping land leads to accelerated erosion processes. Management of riparian land may counteract the negative impacts of higher sediment delivery rates on water quality. This study assessed water and sediment concentration trapping efficiencies of riparian vegetation in northern Laos and the effect of cultivation of riparian land on water quality. Runoff flowing in and out of selected riparian sites was monitored by means of open troughs. In 2005, two native grass, two bamboo, and two banana sites were monitored. In 2006, adjacent to steep banana, bamboo, and native grass sites, three upland rice sites were established and monitored. Water trapping efficiency (WTE) and sediment concentration trapping efficiency (SCTE) were calculated on an event basis; means and 95% confidence intervals (CIs) were estimated with a bootstrapping approach. Confidence intervals were large and overlapping among sites. Seepage conditions severely limited trapping efficiency. Native grass resulted in the highest WTE (95% CI, -0.10 to 0.23), which was not significantly different from zero. Banana resulted in the highest SCTE (95% CI, 0.06-0.40). Bamboo had negative WTE and SCTE. Median outflow runoff from rice sites was nine times the inflow. Median outflow sediment concentration from rice sites was two to five times that of their adjacent sites and two to five times the inflow sediment concentration. Although low-tillage banana plantation may reduce sediment concentration of runoff, cultivation of annual crops in riparian land leads to delivery of turbid runoff into the stream, thus severely affecting stream water quality. PMID:18453411

  20. Asia Rice Crop Estimation and Monitoring (Asia-RiCE) for GEOGLAM

    NASA Astrophysics Data System (ADS)

    Oyoshi, K.; Tomiyama, N.; Okumura, T.; Sobue, S.

    2013-12-01

    Food security is a critical issue for the international community because of rapid population and economic growth, and climate change. In June 2011, the meeting of G20 agriculture ministers was held to discuss food security and food price volatility, and they agreed on an 'Action Plan on Food Price Volatility and Agriculture'. This plan includes a GEO Global Agricultural Monitoring (GEOGLAM) initiative. The aim of GEOGLAM is to reinforce the international community's ability to produce and disseminate relevant, timely, and accurate forecasts of agricultural production on regional, national, and global scales by utilizing remote sensing technology. GEOGLAM focused on four major grain crops, wheat, maize, soybeans and rice. In particular, Asian countries are responsible for approximately 90% of the world rice production and consumption, rice is the most significant cereal crop in Asian region. Hence, Asian space and agricultural agencies with an interest in the development of rice crop monitoring technology launched an Asia-Rice Crop Estimation & Monitoring (Asia-RiCE) component for the GEOGLAM initiative. In Asian region, rice is mainly cultivated in rainy season, and a large amount of cloud limits rice crop monitoring with optical sensors. But, Synthetic Aperture RADAR (SAR) is all-weather sensor and can observe land surface even if the area is covered by cloud. Therefore, SAR technology would be powerful tool to monitor rice crop in Asian region. Asia-RiCE team required mainly SAR observation data including ALOS-2, RISAT-1, Sentinel-1 and RADARSAT, TerraSAR-X, COSMO-SkyMed for Asia-RiCE GEOGLAM Phase 1 implementation (2013-2015) to the Committee on Earth Observations (CEOS) in the GEOGLAM-CEOS Global Agricultural Monitoring Co-community Meeting held in June 2013. And also, rice crop has complicated cropping systems such as rein-fed or irrigated cultivation, single, double or sometimes triple cropping. In addition, each agricultural field is smaller than that of

  1. [Effects of mechanical transplanting of rice with controlled release bulk blending fertilizer on rice yield and soil fertility].

    PubMed

    Zhang, Xuan; Ding, Jun-Shan; Liu, Yan-Ling; Gu, Yan; Han, Ke-Feng; Wu, Liang-Huan

    2014-03-01

    Abstract: A 2-year field experiment with a yellow-clay paddy soil in Zhejiang Province was conducted to study the effects of different planting measures combined with different fertilization practices on rice yield, soil nutrients, microbial biomass C and N and activities of urease, phosphatase, sucrase and hydrogen peroxidase at the maturity stage. Results showed that mechanical transplanting of rice with controlled release bulk blending (BB) fertilizer (BBMT) could achieve a significantly higher mean yield than traditional manual transplanting with traditional fertilizer (TFTM) and direct seeding with controlled release BB fertilizer (BBDS) by 16.3% and 27.0%, respectively. The yield by BBMT was similar to that by traditional manual transplanting with controlled release BB fertilizer (BBTM). Compared with TFTM, BBMT increased the contents of soil total-N, available N, available P and microbial biomass C, and the activities of urease, sucrase and hydrogen peroxidase by 21.5%, 13.6%, 41.2%, 27.1%, 50.0%, 22.5% and 46.2%, respectively. Therefore, BBMT, a simple high-efficiency rice cultivation method with use of a light-weighted mechanical transplanter, should be widely promoted and adopted. PMID:24984497

  2. Sustainable rice production and its impact on the rice value chain: A case study of rural paddy farm in Kedah

    NASA Astrophysics Data System (ADS)

    Othman, Siti Norezam; Othman, Zakirah; Yaacob, Noorulsadiqin Azbiya; Hamid, Kamal Ab

    2016-08-01

    System of Rice Intensification (SRI) method had contributed towards environmental sustainability through improving paddy ecosystem, better sustainable economic due to improving paddy production and sales and social sustainability through local community development through community activity and health. This study aimed to find out whether the innovative practices of SRI affect the rice value chain and to determine the roles, activities of the actors in the value chain as well as challenges that impacted the value chain. Using interview as data collection method, case samples were selected from various SRI paddy site in Kedah. The findings indicated that implementing SRI practices in organic paddy cultivation had caused the value chain to be different from conventional paddy value chain in terms of actor and effect of middle man subject to the small scale paddy production. For organic rice value chain to become competitive, roles, activities and challenges were identified so that supports could be provided to the farmers and other related parties in the value chain.

  3. Black versus Black: The Relationship among African, African American, and African Caribbean Persons.

    ERIC Educational Resources Information Center

    Jackson, Jennifer V.; Cothran, Mary E.

    2003-01-01

    Surveyed people of African descent regarding relationships among African, African-American, and African-Caribbean persons, focusing on contact and friendship, travel to countries of the diaspora, cross-cultural communication, thoughts and stereotypes, and education. Most respondents had contacts with the other groups, but groups had preconceived…

  4. Gene flow from herbicide-resistant and non-resistant rice into red rice populations in U.S. rice fields: A survey of current evidence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diverse red rice types infest U.S. rice fields. These infestations have remained widespread despite recent successes in controlling red rice in newly-introduced herbicide-resistant rice systems. As a result, the distribution and genetic background of red rice, and the degree to which red rice inte...

  5. Cassava; African perspective on space agriculture

    NASA Astrophysics Data System (ADS)

    Katayama, Naomi; Njemanze, Philip; Nweke, Felix; Space Agriculture Task Force, J.; Katayama, Naomi; Yamashita, Masamichi

    Looking on African perspective in space agriculture may contribute to increase diversity, and enforce robustness for advanced life support capability. Cassava, Manihot esculentaand, is one of major crop in Africa, and could be a candidate of space food materials. Since resource is limited for space agriculture in many aspects, crop yield should be high in efficiency, and robust as well. The efficiency is measured by farming space and time. Harvest yield of cassava is about 41 MJ/ m2 (70 ton/ha) after 11 months of farming. Among rice, wheat, potato, and sweet potato, cassava is ranked to the first place (40 m2 ) in terms of farming area required to supply energy of 5 MJ/day, which is recommended for one person. Production of cassava could be made under poor condition, such as acidic soil, shortage of fertilizer, draught. Laterite, similar to Martian regolith. Propagation made by stem cutting is an advantage of cassava in space agriculture avoiding entomophilous or anemophilous process to pollinate. Feature of crop storage capability is additional factor that determines the efficiency in the whole process of agriculture. Cassava root tuber can be left in soil until its consumption. Cassava might be an African contribution to space agriculture.

  6. [Impacts of cultivated land conversion on cultivated land productivity in China: prediction and analysis].

    PubMed

    Jiang, Qun-ou; Deng, Xiang-zheng; Lin, Ying-zhi; Cui, Yong-wei

    2010-12-01

    This paper simulated the spatial patterns of cultivated land in China under the future scenario by using the Dynamics of Land System (DLS) model, and then estimated the cultivated land productivity at the grid pixel dimensions based on the Estimation System of Land Production (ESLP). In addition, the spatial patterns of cultivated land productivity in each of China agro-ecological zones were analyzed. On this basis, this paper predicted the impacts of cultivated land conversion on the cultivated land production in China in 2000-2020, and identified the major affecting factors on the cultivated land production. The research results indicated that the impact of improving the cultivated land productivity on the cultivated land production would be wunch more remarkable than that from the magnitude of cultivated land conversion in regions where there were high potential to imrprove the cultivated land productivity. However, in the regions with nearly no room to improve the productivity, cultivated land conversion would produce more apparent impacts on the total cultivated land production. In this sense, it was of significance for the national food security in China to adjust the cultivated land conversion to ensure the 0.12 billion hm2 of cultivated land, and to increase investment and improve management level to increase per unit grain yield. PMID:21442997

  7. Astronomy for African development

    NASA Astrophysics Data System (ADS)

    Govender, Kevindran

    2011-06-01

    In recent years there have been a number of efforts across Africa to develop the field of astronomy as well as to reap benefit from astronomy for African people. This presentation will discuss the case of the SALT (Southern African Large Telescope) Collateral Benefits Programme (SCBP) which was set up to ensure societal benefit from astronomy. With African society as the target, the SCBP has embarked on various projects from school level education to public understanding of science to socio-economic development, the latter mainly being felt in the rural communities surrounding the South African Astronomical Observatory (home to SALT). A development plan for ``Astronomy in Africa'' will also be discussed. This plan has been drawn up with input from all over Africa and themed ``Astronomy for Education''. The Africa case stands as a good example for the IYA cornerstone project ``Developing Astronomy Globally'' which focuses on developing regions.

  8. African American Suicide

    MedlinePlus

    ... accounted for 83.8% of Caucasian elderly suicides. • Firearms were the predominant method of suicide among African ... per 100,000 annually. Source: Centers for Disease Control and Prevention. National Vital Statistics System. Mortality Data. ...

  9. CULTIVAR SPECIFIC RESPONSE TO THE HOST-SELECTIVE TOXIN PRODUCED BY RHIZOCTONIA SOLANI, THE CAUSAL PATHOGEN OF SHEATH BLIGHT DISEASE Of RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheath Blight, caused by Rhizoctonia solani, is widely regarded as one of the most important diseases of cultivated rice and germplasm improvement is essential for disease management. Genetic sources of tolerance for this disease are known, however, complex quantitative inheritance and high environ...

  10. Mapping Rice Production in China with AVHRR Imagery

    NASA Technical Reports Server (NTRS)

    Paliouras, Eleni J.; Emery, William

    2001-01-01

    The study of rice agriculture is necessary for both the importance of rice as a vital food source and because of the fact that cultivating it has an unfortunate byproduct, namely methane gas. As a food source, rice is a staple for a large majority of the world's population, especially in Asia. Because the populations of many Asian nations are increasing at rapid rates, the production of rice will need to similarly increase. In 1989, it was estimated that the demand for rice would increase by 65% by the year 2019. Rice crops are considered to be one of the primary anthropogenic sources of methane gas. A reason for concern is that this gas is a so-called "greenhouse" trace gas and given its increasing levels in the atmosphere, is thought to contribute to the suspected global warming phenomenon. Some estimate that methane may contribute up to 20% to the global warming effect. Trace gas emissions from anthropogenic sources is an issue that generates great worldwide interest because of the fact that mankind is very likely affecting the current and future climate in potentially negative ways. In an effort to better understand these effects, scientists and engineers are conducting research on all of the varied fronts which relate to climate change and biosphere/atmosphere interactions. The study of global warming through increasing concentrations of greenhouse gases is one area which has received much media and scientific attention. Research fueled by debates on this topic is being conducted on numerous, interrelated fronts in an effort to better understand the complex relationship between human activities and the earth's climate. The research ranges from attempting to verify if the observed data even supports the existence of an anthropogenically generated global-warming phenomenon, to identification of sources and sinks of the trace gases, to measuring the source strengths, to studies which focus on modeling the processes which generate the gases, and finally, to trying

  11. Seaweed cultivation: Traditional way and its reformation

    NASA Astrophysics Data System (ADS)

    Fei, Xiu-Geng; Bao, Ying; Lu, Shan

    1999-09-01

    Seaweed cultivation or phycoculture has been developed rather fast in recent years. The total production of cultivated seaweed at present is about 6250×103 tons fresh weight. The total cultivation area is estimated as 200×103 hectare. The annual total value of cultivated seaweeds has been estimated to be more than 3 billion US dollars. Phycoculture provides many job opportunities for the coastal region people, has the potential to improve marine environments and thus even induce global change. All traditional cultivation methods and techniques are based on or start from the individual plant or the cultivated seaweed population. Modern biological science and biotechnology achievements have benefited agriculture a lot, but traditional seaweed cultivation has not changed much since its founding. This is because seaweed cultivation has been quite conservative for quite a long period and has accumulated many problems requiring solution. Four main problems might be the most universal ones holding back further development of the industry. New ways of seaweed cultivation must be developed, new techniques must be perfected, and new problems solved. This paper mainly discusses the main problems of traditional seaweed cultivation at present and its possible further development and reformation in the future.

  12. Water management impacts on arsenic behavior and rhizosphere bacterial communities and activities in a rice agro-ecosystem.

    PubMed

    Das, Suvendu; Chou, Mon-Lin; Jean, Jiin-Shuh; Liu, Chia-Chuan; Yang, Huai-Jen

    2016-01-15

    Although rice cultivated under water-saturated conditions as opposed to submerged conditions has received considerable attention with regard to reducing As levels in rice grain, the rhizosphere microbiome potentially influencing As-biotransformation and bioavailability in a rice ecosystem has rarely been studied. In this study, the impacts of flooded, non-flooded and alternate wetting and drying (AWD) practices on rhizosphere bacterial composition and activities that could potentially impact As speciation and accumulation in rhizosphere soil and pore water, As fractions in rhizosphere soil and As speciation and distribution in plant parts were assessed. The results revealed that in addition to pore water As concentration, non-specifically sorbed As fraction, specifically sorbed As fraction and amorphous iron oxide bound As fraction in soil were bio-available to rice plants. In the flooded treatment, As(III) in the pore water was the predominant As species, accounting for 87.3-93.6% of the total As, whereas in the non-flooded and AWD treatments, As(V) was the dominant As species, accounting for 89.6-96.2% and 73.0-83.0%, respectively. The genera Ohtaekwangia, Geobacter, Anaeromyxobacter, Desulfuromonas, Desulfocapsa, Desulfobulbus, and Lacibacter were found in relatively high abundance in the flooded soil, whereas the genera Acinetobacter, Ignavibacterium, Thiobacillus, and Lysobacter were detected in relatively high abundance in the non-flooded soil. Admittedly, the decrease in As level in rice cultivated under the non-flooded and AWD conditions was mostly linked to a relatively high soil redox potential, low As(III) concentration in the soil pore water, a decrease in the relative abundance of As-, Fe- and sulfur-reducing bacteria and an increase in the relative abundance of As-, Fe- and sulfur-oxidizing bacteria in the rhizosphere soil of the rice. This study demonstrated that with substantial reduction in grain As levels and higher water productivity, AWD

  13. Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

    PubMed Central

    2010-01-01

    Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru), unplanned rice cultivation (Kiamachiri) and non-irrigated (Murinduko) agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252), respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval abundance. Conclusion

  14. Rice Crop Monitoring by Earth Observation Data in the Asian Region

    NASA Astrophysics Data System (ADS)

    Oyoshi, K.; Sobue, S.; Tomiyama, N.; Okumura, T.; Rakwatin, P.

    2012-12-01

    Food security is a critical issue for the international community. In June 2011, the meeting of G20 agriculture ministers was held to discuss global food security and they agreed on an "Action Plan on Food Price Volatility and Agriculture". This plan includes a GEO Global Agricultural Monitoring (GEO-GLAM) initiative which utilizes remote sensing to improve projections of crop production and weather forecasting. Hence, satellite remote sensing is expected to contribute national, regional and global food security through the systematic and efficient collection of food security related information such as agro-meteorological condition, crop growth or yield estimation. Food security related information is utilized to take mitigation strategies or policies to manage food shortages or trading, and ensure food security. Especially in Asia, rice is the most important cereal crop because Asian countries are responsible for approximately 90% of the world rice productions and consumptions. There- fore, Asian countries are expected to contribute GLAM through the construction of rice crop monitoring system. We demonstrated the estimation of rice production, the crop phenology monitoring by Earth Observation (EO) data. The aim of this study is to establish a prototype system designed to provide paddy rice area and yield estimation. Generally, crop yield estimation is consist of two components, cultivated area and yield per area. The cultivated areas of paddy field are detected by the seasonal pattern of SAR data over paddy field. This means paddy field is filled with water just before planting rice, then covered by dense vegetation in growing season. The paddy filed map was derived from the seasonal Advanced Land Observation Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data with a simple threshold method. Then, to estimate rice productivity, we applied a simple rice crop model. The input data to the model are physical and chemical properties of

  15. Global Expression Profiling of Low Temperature Induced Genes in the Chilling Tolerant Japonica Rice Jumli Marshi

    PubMed Central

    Chawade, Aakash; Lindlöf, Angelica; Olsson, Björn; Olsson, Olof

    2013-01-01

    Low temperature is a key factor that limits growth and productivity of many important agronomical crops worldwide. Rice (Oryza sativa L.) is negatively affected already at temperatures below +10°C and is therefore denoted as chilling sensitive. However, chilling tolerant rice cultivars exist and can be commercially cultivated at altitudes up to 3,050 meters with temperatures reaching as low as +4°C. In this work, the global transcriptional response to cold stress (+4°C) was studied in the Nepalese highland variety Jumli Marshi (spp. japonica) and 4,636 genes were identified as significantly differentially expressed within 24 hours of cold stress. Comparison with previously published microarray data from one chilling tolerant and two sensitive rice cultivars identified 182 genes differentially expressed (DE) upon cold stress in all four rice cultivars and 511 genes DE only in the chilling tolerant rice. Promoter analysis of the 182 genes suggests a complex cross-talk between ABRE and CBF regulons. Promoter analysis of the 511 genes identified over-represented ABRE motifs but not DRE motifs, suggesting a role for ABA signaling in cold tolerance. Moreover, 2,101 genes were DE in Jumli Marshi alone. By chromosomal localization analysis, 473 of these cold responsive genes were located within 13 different QTLs previously identified as cold associated. PMID:24349120

  16. What factors influence choice of waste management practice? Evidence from rice straw management in the Philippines.

    PubMed

    Launio, Cheryll C; Asis, Constancio A; Manalili, Rowena G; Javier, Evelyn F; Belizario, Annabelle F

    2014-02-01

    This study applied a multinomial logit model to understand why farmers choose to burn, incorporate or remove rice straw in the field. Four hundred randomly selected farmers were interviewed in four major rice-producing provinces covering the 2009 wet and 2010 dry seasons. Results of the model with burning as the baseline category indicate farm type, location dummies, number of household members with older than 13 years, cow ownership and distance from farm to house as significant variables influencing farmers' choice of straw incorporation or removal over burning. Significant perception variables are the negative impacts of open-field burning, awareness of environmental regulations and attitude towards incentives. Other factors significantly influencing the decision to incorporate over-burn are training attendance and perceptions of effects of straw incorporation. Income from non-rice farming, total area cultivated, tenure status, presence of burning and solid waste management provincial ordinances are significant factors affecting choice to remove over burn. Continually providing farmers' training in rice production, increasing demand for rice straw for other uses, and increasing awareness of environmental laws and regulations are policy directions recommended. PMID:24519228

  17. Quantitative Trait Loci Mapping for Bacterial Blight Resistance in Rice Using Bulked Segregant Analysis

    PubMed Central

    Han, Xueying; Yang, Yong; Wang, Xuming; Zhou, Jie; Zhang, Wenhao; Yu, Chulang; Cheng, Chen; Cheng, Ye; Yan, Chengqi; Chen, Jianping

    2014-01-01

    Oryza meyeriana is highly resistant to rice bacterial blight (BB) and this resistance trait has been transferred to cultivated rice (O. sativa) using asymmetric somatic hybridization. However, no resistance genes have yet been cloned. In the present study, a progeny of the somatic hybridization with high BB resistance was crossed with a rice cultivar with high BB susceptibility to develop an F2 population. Using bulked segregant analysis (BSA), 17 polymorphic markers that were linked to rice BB resistance were obtained through scanning a total of 186 simple sequence repeats (SSR) and sequence-tagged site (STS) markers, evenly distributed on 12 chromosomes. A genetic linkage map was then constructed based on the 17 linkage markers and the F2 segregating population, which was followed by mapping for quantitative trait loci (QTLs) for BB resistance. Three QTLs were identified on chromosomes 1, 3 and 5, respectively, and the alleles of the resistant parent at any of the QTLs increased BB resistance. All of the three QTLs had a strong effect on resistance, explaining about 21.5%, 12.3% and 39.2% of the resistance variance, respectively. These QTLs were different from the loci of the BB resistance genes that have been identified in previous studies. The QTLs mapped in this work will facilitate the isolation of novel BB resistance genes and their utilization in rice resistance breeding. PMID:24995697

  18. Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants

    PubMed Central

    2014-01-01

    Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO2 concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO2 m−2 s−1), internal CO2 concentration (336.97 ppm), water use efficiency (1.15 μmoCO2/mmoH2O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation. PMID:24949276

  19. Evaluating Leaf and Canopy Reflectance of Stressed Rice Plants to Monitor Arsenic Contamination.

    PubMed

    Bandaru, Varaprasad; Daughtry, Craig S; Codling, Eton E; Hansen, David J; White-Hansen, Susan; Green, Carrie E

    2016-01-01

    Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor arsenic in rice plants. Four arsenic levels were induced in hydroponically grown rice plants with application of 0, 5, 10 and 20 µmol·L(-1) sodium arsenate. Reflectance spectra of upper fully expanded leaves were acquired over visible and infrared (NIR) wavelengths. Additionally, canopy reflectance for the four arsenic levels was simulated using SAIL (Scattering by Arbitrarily Inclined Leaves) model for various soil moisture conditions and leaf area indices (LAI). Further, sensitivity of various vegetative indices (VIs) to arsenic levels was assessed. Results suggest that plants accumulate high arsenic amounts causing plant stress and changes in reflectance characteristics. All leaf spectra based VIs related strongly with arsenic with coefficient of determination (r²) greater than 0.6 while at canopy scale, background reflectance and LAI confounded with spectral signals of arsenic affecting the VIs' performance. Among studied VIs, combined index, transformed chlorophyll absorption reflectance index (TCARI)/optimized soil adjusted vegetation index (OSAVI) exhibited higher sensitivity to arsenic levels and better resistance to soil backgrounds and LAI followed by red edge based VIs (modified chlorophyll absorption reflectance index (MCARI) and TCARI) suggesting that these VIs could prove to be valuable aids for monitoring arsenic in rice fields. PMID:27322304

  20. Evaluating Leaf and Canopy Reflectance of Stressed Rice Plants to Monitor Arsenic Contamination

    PubMed Central

    Bandaru, Varaprasad; Daughtry, Craig S.; Codling, Eton E.; Hansen, David J.; White-Hansen, Susan; Green, Carrie E.

    2016-01-01

    Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor arsenic in rice plants. Four arsenic levels were induced in hydroponically grown rice plants with application of 0, 5, 10 and 20 µmol·L−1 sodium arsenate. Reflectance spectra of upper fully expanded leaves were acquired over visible and infrared (NIR) wavelengths. Additionally, canopy reflectance for the four arsenic levels was simulated using SAIL (Scattering by Arbitrarily Inclined Leaves) model for various soil moisture conditions and leaf area indices (LAI). Further, sensitivity of various vegetative indices (VIs) to arsenic levels was assessed. Results suggest that plants accumulate high arsenic amounts causing plant stress and changes in reflectance characteristics. All leaf spectra based VIs related strongly with arsenic with coefficient of determination (r2) greater than 0.6 while at canopy scale, background reflectance and LAI confounded with spectral signals of arsenic affecting the VIs’ performance. Among studied VIs, combined index, transformed chlorophyll absorption reflectance index (TCARI)/optimized soil adjusted vegetation index (OSAVI) exhibited higher sensitivity to arsenic levels and better resistance to soil backgrounds and LAI followed by red edge based VIs (modified chlorophyll absorption reflectance index (MCARI) and TCARI) suggesting that these VIs could prove to be valuable aids for monitoring arsenic in rice fields. PMID:27322304

  1. Diversity and functional traits of culturable microbiome members, including cyanobacteria in the rice phyllosphere.

    PubMed

    Venkatachalam, S; Ranjan, K; Prasanna, R; Ramakrishnan, B; Thapa, S; Kanchan, A

    2016-07-01

    The diversity and abundance of culturable microbiome members of the rice phyllosphere was investigated using cv. Pusa Punjab Basmati 1509. Both diversity and species richness of bacteria were significantly higher in plants in pots in a semi-controlled environment than those in fields. Application of fertilisers reduced both diversity and species richness in field-grown plants under a conventional flooded system of rice intensification (SRI) and in dry-seeded rice (DSR) modes. Sequence analyses of 16S rDNA of culturable bacteria, those selected after amplified ribosomal DNA restriction analysis (ARDRA), showed the dominance of α-proteobacteria (35%) and actinobacteria (38%); Pantoea, Exiguobacterium and Bacillus were common among the culturable phyllospheric bacteria. About 34% of 83 culturable bacterial isolates had higher potential (>2 μg·ml(-1) ) for indole acetic acid production in the absence of tryptophan. Interestingly, the phyllosphere bacterial isolates from the pot experiment had significantly higher potential for nitrogen fixation than isolates from the field experiment. Enrichment for cyanobacteria showed both unicellular forms and non-heterocystous filaments under aerobic as well as anaerobic conditions. PCR-DGGE analysis of these showed that aerobic and anaerobic conditions as well as the three modes of cultivation of rice in the field strongly influenced the number and abundance of phylotypes. The adaptability and functional traits of these culturable microbiome members suggest enormous diversity in the phyllosphere, including potential for plant growth promotion, which was also significantly influenced by the different methods of growing rice. PMID:26849835

  2. Seaweed cultivation for renewable resources

    SciTech Connect

    Bird, K.T.; Benson, P.H.

    1987-01-01

    In the 1970's and 80's, major research and development programs were launched to explore the possibility of using marine biomass as a source of energy. This volume, not only reviews the accomplishments of the aforementioned programs, but also describes how this research relates to seaweed cultivation for other products, such as food, feed, and high value chemicals. Topics covered include the features of marine biomass production, biotechnological manipulations of marine algae, and marine biomass conversion to energy, as well as economics. The chapters synthesize a large number of technical reports, journal articles, symposia and conference proceedings and technology transfer meetings.

  3. Carbon and water cycling in flooded and rainfed rice (Oryza Sativa) ecosystem: Disentangling agronomical and ecological aspects of water use efficiency

    NASA Astrophysics Data System (ADS)

    Nay-Htoon, Bhone; Xue, Wei; Dubbert, Maren; Lindner, Steve; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    Agricultural crops play an important role in the global carbon and water cycling process and there is intense research to understand and predict carbon and water fluxes, productivity and water use of cultivated crops under climate change. Mechanistic understanding of the trade of between ecosystem water use efficiency and agronomic water use efficiency to maintain higher crop yield and productive water loss is necessary for the ecosystem sustainability. . We compared water and carbon fluxes of paddy and rainfed rice by canopy scale gas exchange measurements, crop growth, and daily evapotranspiration, transpiration and carbon flux modeling. According to our findings, evaporation contributed strongly (maximum 100% to minimum 45%) to paddy rice evapotranspiration while transpiration of rainfed is almost 50 % of daily evapotranspiration. Water use efficiency (WUE) was higher in rainfed rice both from an agronomic (WUEagro, i.e. grain yield per evapotranspiration) and ecosystem (WUEeco, i.e. gross primary production per evapotranspiration) perspective. However, rainfed rice showed also high ecosystem respiration losses and a slightly lower crop yield, demonstrating that higher WUE in rainfed rice comes at the expense of higher respiration losses of assimilated carbon and lower plant production, compared to paddy rice. Our results highlighted the need to partition water and carbon fluxes to improve our mechanistic understanding of water use efficiency and environmental impact of different agricultural practices. Keywords: Rainfed rice, Paddy rice, water use efficiency, Transpiration/Evapotranspiration, ecosystem WUE, agronomic WUE, Evapotranspiration

  4. [Effects of increased planting density with reduced nitrogen fertilizer application on rice yield, N use efficiency and greenhouse gas emission in Northeast China].

    PubMed

    Zhu, Xiang-cheng; Zhang, Zhen-ping; Zhang, Jun; Deng, Ai-xing; Zhang, Wei-jian

    2016-02-01

    The traditional rice growing practice has to change to save resource and protect environment, and it' s necessary to develop new technology in rice cultivation. Therefore, a two-year field experiment of Japonica rice (Liaoxing 1) was conducted in Northeast China in 2012 and 2013 to investigate the integrated effects of dense planting with less basal nitrogen (N) and unchanged top-dressing N (IR) on rice yield, N use efficiency (NUE) and greenhouse gas emissions. Compared with traditional practice (CK), we increased the rice seedling density by 33.3% and reduced the basal N rate by 20%. The results showed that the average N agronomy efficiency and partial factor productivity were improved by 49.6% (P<0.05) and 20.4% (P<0.05), respectively, while the area and yield-scaled greenhouse gas emissions were reduced by 9.9% and 12.7% (P<0.05), respectively. Although IR cropping mode decreased panicle number and biomass production, it significantly enhanced rice seed setting rate and harvest index, resulting in an unchanged or even highei yield. NH4+-N and NO3(-)-N concentrations in rice rhizosphere soil were reduced, resulting in an increment of N recovery efficiency. Generally, proper dense planting with less basal N applicatior could be a good approach for the trade-off between rice yield, NUE and greenhouse gas emission. PMID:27396117

  5. The estimation of rice paddy yield with GRAMI crop model and Geostationary Ocean Color Imager (GOCI) image over South Korea

    NASA Astrophysics Data System (ADS)

    Yeom, J. M.; Kim, H. O.

    2014-12-01

    In this study, we estimated the rice paddy yield with moderate geostationary satellite based vegetation products and GRAMI model over South Korea. Rice is the most popular staple food for Asian people. In addition, the effects of climate change are getting stronger especially in Asian region, where the most of rice are cultivated. Therefore, accurate and timely prediction of rice yield is one of the most important to accomplish food security and to prepare natural disasters such as crop defoliation, drought, and pest infestation. In the present study, GOCI, which is world first Geostationary Ocean Color Image, was used for estimating temporal vegetation indices of the rice paddy by adopting atmospheric correction BRDF modeling. For the atmospheric correction with LUT method based on Second Simulation of the Satellite Signal in the Solar Spectrum (6S), MODIS atmospheric products such as MOD04, MOD05, MOD07 from NASA's Earth Observing System Data and Information System (EOSDIS) were used. In order to correct the surface anisotropy effect, Ross-Thick Li-Sparse Reciprocal (RTLSR) BRDF model was performed at daily basis with 16day composite period. The estimated multi-temporal vegetation images was used for crop classification by using high resolution satellite images such as Rapideye, KOMPSAT-2 and KOMPSAT-3 to extract the proportional rice paddy area in corresponding a pixel of GOCI. In the case of GRAMI crop model, initial conditions are determined by performing every 2 weeks field works at Chonnam National University, Gwangju, Korea. The corrected GOCI vegetation products were incorporated with GRAMI model to predict rice yield estimation. The predicted rice yield was compared with field measurement of rice yield.

  6. Evidence for divergence of response in Indica, Japonica, and wild rice to high CO2 × temperature interaction.

    PubMed

    Wang, Diane R; Bunce, James A; Tomecek, Martha B; Gealy, David; McClung, Anna; McCouch, Susan R; Ziska, Lewis H

    2016-07-01

    High CO2 and high temperature have an antagonistic interaction effect on rice yield potential and present a unique challenge to adapting rice to projected future climates. Understanding how the differences in response to these two abiotic variables are partitioned across rice germplasm accessions may be key to identifying potentially useful sources of resilient alleles for adapting rice to climate change. In this study, we evaluated eleven globally diverse rice accessions under controlled conditions at two carbon dioxide concentrations (400 and 600 ppm) and four temperature environments (29 °C day/21 °C night; 29 °C day/21 °C night with additional heat stress at anthesis; 34 °C day/26 °C night; and 34 °C day/26 °C night with additional heat stress at anthesis) for a suite of traits including five yield components, five growth characteristics, one phenological trait, and four photosynthesis-related measurements. Multivariate analyses of mean trait data from these eight treatments divide our rice panel into two primary groups consistent with the genetic classification of INDICA/INDICA-like and JAPONICA populations. Overall, we find that the productivity of plants grown under elevated [CO2 ] was more sensitive (negative response) to high temperature stress compared with that of plants grown under ambient [CO2 ] across this diversity panel. We report differential response to CO2 × temperature interaction for INDICA/INDICA-like and JAPONICA rice accessions and find preliminary evidence for the beneficial introduction of exotic alleles into cultivated rice genomic background. Overall, these results support the idea of using wild or currently unadapted gene pools in rice to enhance breeding efforts to secure future climate change adaptation. PMID:26959982

  7. A comparison of methane emissions following rice paddies conversion to crab-fish farming wetlands in southeast China.

    PubMed

    Hu, Zhiqiang; Wu, Shuang; Ji, Cheng; Zou, Jianwen; Zhou, Quansuo; Liu, Shuwei

    2016-01-01

    Rice paddies and aquaculture wetlands are typical agricultural wetlands that constitute one of the important sources of atmospheric methane (CH4). Traditional transplanted rice paddies have been experiencing conversion to pond aquaculture wetlands for pursuing higher economic benefits over the past decades in southeast China. A parallel field experiment was carried out to compare CH4 emissions from a transplanted rice paddy and its converted crab-fish farming wetland in southeast China. Over the rice-growing season, CH4 fluxes averaged 1.86 mg m(-2) h(-1) from rice paddies, and 1.14 and 0.50 mg m(-2) h(-1) for the treatments with or without aquatic vegetation present in the crab-fish farming wetlands, respectively. When averaged across the treatments, seasonal CH4 emissions from crab-fish framing wetlands were 52% lower than those from rice paddies. The CH4 fluxes were negatively related to water dissolved oxygen (DO) concentration but positively related to soil/sediment dissolved organic carbon (DOC) content in crab-fish farming wetlands. Dependence of CH4 fluxes on DO or DOC was intensified by the aquatic vegetation presence. By extrapolating the present CH4 emission rate with the current rice paddy-converted aquaculture cultivation area, the seasonal CH4 emissions from inland aquaculture wetlands during the critical farming stage (20 June to 18 October) were estimated to be 33.6 Gg ha(-1) in southeast China in 2012. Rice paddies conversion to crab-fish farming wetlands might have reduced CH4 emissions by 22-54% in mainland China. Results of this study suggest that the conversion of transplanted rice paddies to crab-fish aquaculture wetlands for higher economic benefits would also lead to a lower ecosystem CH4 release rate. PMID:26374545

  8. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances.

    PubMed

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot(-1)). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot(-1)) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot(-1)) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials. PMID:25977938

  9. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    PubMed Central

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot−1) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials. PMID:25977938

  10. Production of red mold rice using a modified Nagata type koji maker.

    PubMed

    Chiu, Chiu-Hsia; Ni, Kuang-Huei; Guu, Yuan-Kuang; Pan, Tzu-Ming

    2006-11-01

    In this research, a commercial koji maker with a rotary perforated bed of 5-m diameter was modified for red mold rice production. Monascus purpureus BCRC 31499 was selected for its high production capacities of monacolin K and red pigment. The selected strain was first cultivated in a 120-l submerged type fermentor at 34 degrees C and 2 vvm aeration rate with 60 rpm agitation for 5 days using 20% liquefied rice porridge as carbon source. The high concentration red mold rice broth (>3.5 g/ml) was harvested for inocula and well mixed with cooked rice to an initial concentration of 2% v/w. The inoculated cooked rice then was directed into the modified koji maker, in which temperature and humidity profiles were kept at varied levels at different stages, respectively. Air was circulated to remove fermentation heat while the perforated bed rotated slowly for providing mild agitation. Lag phase of the Monascus sp. in the modified koji maker was determined to be 16 h by the time the koji temperature raised rapidly. Water was added into the koji bed by a water curtain at the 36th hour to keep the moisture content of the rice koji at 50% or above. At the final stage, temperature was adjusted to 34 degrees C to direct red pigment production. After 7 days, 1,200-kg high quality red mold rice was harvested per batch. Labor costs, space, and fermentation time were reduced tremendously compared with those made by traditional methods. PMID:17028877

  11. Structure, variation, and assembly of the root-associated microbiomes of rice

    PubMed Central

    Edwards, Joseph; Johnson, Cameron; Santos-Medellín, Christian; Lurie, Eugene; Podishetty, Natraj Kumar; Bhatnagar, Srijak; Eisen, Jonathan A.; Sundaresan, Venkatesan

    2015-01-01

    Plants depend upon beneficial interactions between roots and microbes for nutrient availability, growth promotion, and disease suppression. High-throughput sequencing approaches have provided recent insights into root microbiomes, but our current understanding is still limited relative to animal microbiomes. Here we present a detailed characterization of the root-associated microbiomes of the crop plant rice by deep sequencing, using plants grown under controlled conditions as well as field cultivation at multiple sites. The spatial resolution of the study distinguished three root-associated compartments, the endosphere (root interior), rhizoplane (root surface), and rhizosphere (soil close to the root surface), each of which was found to harbor a distinct microbiome. Under controlled greenhouse conditions, microbiome composition varied with soil source and genotype. In field conditions, geographical location and cultivation practice, namely organic vs. conventional, were factors contributing to microbiome variation. Rice cultivation is a major source of global methane emissions, and methanogenic archaea could be detected in all spatial compartments of field-grown rice. The depth and scale of this study were used to build coabundance networks that revealed potential microbial consortia, some of which were involved in methane cycling. Dynamic changes observed during microbiome acquisition, as well as steady-state compositions of spatial compartments, support a multistep model for root microbiome assembly from soil wherein the rhizoplane plays a selective gating role. Similarities in the distribution of phyla in the root microbiomes of rice and other plants suggest that conclusions derived from this study might be generally applicable to land plants. PMID:25605935

  12. Structure, variation, and assembly of the root-associated microbiomes of rice.

    PubMed

    Edwards, Joseph; Johnson, Cameron; Santos-Medellín, Christian; Lurie, Eugene; Podishetty, Natraj Kumar; Bhatnagar, Srijak; Eisen, Jonathan A; Sundaresan, Venkatesan

    2015-02-24

    Plants depend upon beneficial interactions between roots and microbes for nutrient availability, growth promotion, and disease suppression. High-throughput sequencing approaches have provided recent insights into root microbiomes, but our current understanding is still limited relative to animal microbiomes. Here we present a detailed characterization of the root-associated microbiomes of the crop plant rice by deep sequencing, using plants grown under controlled conditions as well as field cultivation at multiple sites. The spatial resolution of the study distinguished three root-associated compartments, the endosphere (root interior), rhizoplane (root surface), and rhizosphere (soil close to the root surface), each of which was found to harbor a distinct microbiome. Under controlled greenhouse conditions, microbiome composition varied with soil source and genotype. In field conditions, geographical location and cultivation practice, namely organic vs. conventional, were factors contributing to microbiome variation. Rice cultivation is a major source of global methane emissions, and methanogenic archaea could be detected in all spatial compartments of field-grown rice. The depth and scale of this study were used to build coabundance networks that revealed potential microbial consortia, some of which were involved in methane cycling. Dynamic changes observed during microbiome acquisition, as well as steady-state compositions of spatial compartments, support a multistep model for root microbiome assembly from soil wherein the rhizoplane plays a selective gating role. Similarities in the distribution of phyla in the root microbiomes of rice and other plants suggest that conclusions derived from this study might be generally applicable to land plants. PMID:25605935

  13. Soil Incorporation of Silica-Rich Rice Husk Decreases Inorganic Arsenic in Rice Grain.

    PubMed

    Seyfferth, Angelia L; Morris, Andrew H; Gill, Rattandeep; Kearns, Kelli A; Mann, Jessica N; Paukett, Michelle; Leskanic, Corey

    2016-05-18

    Arsenic decreases rice yield, and inorganic grain As threatens human health; thus, strategies to decrease rice As are critically needed. Increased plant-available silica (Si) can decrease rice As, yet the source of Si matters. Rice husk, an underutilized and Si-rich byproduct of rice production that contains less labile C and an order of magnitude less As than rice straw, may be an economically viable Si resource to decrease rice As, yet the impact of rice husk incorporation on As in the rice-soil nexus has not been reported. This proof-of-concept study shows that rice husk incorporation to soil (1% w/w) decreases inorganic grain As by 25-50% without negatively affecting grain Cd, yield, or dissolved CH4 levels. Rice husk is a critical yet perhaps overlooked resource to improve soil quality through enhanced nutrient availability and attenuate human health risks through consumption of As-laden grain. PMID:27109244

  14. Rice scene radiation research plan

    NASA Technical Reports Server (NTRS)

    Heilman, J.

    1982-01-01

    Data requirements, tasks to be accomplished, and the technical approaches to be used in identifying the characteristics of rice for crop inventories are listed as well as methods for estimating crop development and assessing its conditions.

  15. Rice Reoviruses in Insect Vectors.

    PubMed

    Wei, Taiyun; Li, Yi

    2016-08-01

    Rice reoviruses, transmitted by leafhopper or planthopper vectors in a persistent propagative manner, seriously threaten the stability of rice production in Asia. Understanding the mechanisms that enable viral transmission by insect vectors is a key to controlling these viral diseases. This review describes current understanding of replication cycles of rice reoviruses in vector cell lines, transmission barriers, and molecular determinants of vector competence and persistent infection. Despite recent breakthroughs, such as the discoveries of actin-based tubule motility exploited by viruses to overcome transmission barriers and mutually beneficial relationships between viruses and bacterial symbionts, there are still many gaps in our knowledge of transmission mechanisms. Advances in genome sequencing, reverse genetics systems, and molecular technologies will help to address these problems. Investigating the multiple interaction systems among the virus, insect vector, insect symbiont, and plant during natural infection in the field is a central topic for future research on rice reoviruses. PMID:27296147

  16. Interactive effects of straw-derived biochar and N fertilization on soil C storage and rice productivity in rice paddies of Northeast China.

    PubMed

    Sui, Yanghui; Gao, Jiping; Liu, Caihong; Zhang, Wenzhong; Lan, Yu; Li, Shuhang; Meng, Jun; Xu, Zhengjin; Tang, Liang

    2016-02-15

    Impacts of biochar on greenhouse gas emissions and C sequestration in agricultural soils have been considered as the key to mitigate climate change. There is limited knowledge regarding the effects of rice straw-derived biochar and interaction with N fertilization on soil C sequestration and rice productivity in fertile paddy fields. A 2-year (2013 and 2014) consecutive field trial was performed using straw treatment (5.05 t ha(-1)) and biochar amendment (0, 1.78, 14.8 and 29.6 t ha(-1)) with or without urea application in a rice paddy in Northeast China. A super high yielding rice variety (Oryza sativa L. subsp. Japonica cv. 'Shennong 265') was cultivated with permanent flooding. Results showed that biochar amendments significantly decreased CH4 emissions relative to straw treatment irrespective of N fertilization, especially in N-fertilized soils with 1.78 t ha(-1) biochar. There were no differences in CO2 emissions with respect to biochar amendments, except for 14.8 t ha(-1) biochar with N fertilization. Straw treatment had the highest global warming potential over a 100-year time frame, which was nearly 1.5 times that of 14.8 t ha(-1) biochar amendment without N fertilization. Biochar addition increased total soil C by up to 5.75 mg g(-1) and 11.69 mg g(-1) (with 14.8 and 29.6 t ha(-1) biochar, respectively), whereas straw incorporation increased this value by only 3.92 mg g(-1). The aboveground biomass of rice in biochar-amended soils increased to varying degrees compared with that in straw-treated soils. However, biochar application had no effects on rice yield, regardless of N fertilization. This study indicated that transforming straw to biochar was more stabilized and more suitable to mitigate greenhouse gas emissions and increase C storage in agriculture soils in Northeast China. PMID:26657366

  17. Storage stability of flour-blasted brown rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brown rice was blasted with rice flour rather than sand in a sand blaster to make microscopic nicks and cuts so that water can easily penetrate into the brown rice endosperm and cook the rice in a shorter time. The flour-blasted American Basmati brown rice, long grain brown rice, and parboiled long...

  18. Dynamics of Seed-Borne Rice Endophytes on Early Plant Growth Stages

    PubMed Central

    Hardoim, Pablo R.; Hardoim, Cristiane C. P.; van Overbeek, Leonard S.; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed. PMID:22363438

  19. Dynamics of seed-borne rice endophytes on early plant growth stages.

    PubMed

    Hardoim, Pablo R; Hardoim, Cristiane C P; van Overbeek, Leonard S; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed. PMID:22363438

  20. Detection algorithm for multiple rice seeds images

    NASA Astrophysics Data System (ADS)

    Cheng, F.; Ying, Y. B.

    2006-10-01

    The objective of this research is to develop a digital image analysis algorithm for detection of multiple rice seeds images. The rice seeds used for this study involved a hybrid rice seed variety. Images of multiple rice seeds were acquired with a machine vision system for quality inspection of bulk rice seeds, which is designed to inspect rice seeds on a rotating disk with a CCD camera. Combining morphological operations and parallel processing gave improvements in accuracy, and a reduction in computation time. Using image features selected based on classification ability; a highly acceptable defects classification was achieved when the algorithm was implemented for all the samples to test the adaptability.

  1. Geochemical patterns and microbial contribution to iron plaque formation in the rice plant rhizosphere

    NASA Astrophysics Data System (ADS)

    Maisch, Markus; Murata, Chihiro; Unger, Julia; Kappler, Andreas; Schmidt, Caroline

    2015-04-01

    Rice is the major food source for more than half of the world population and 80 percent of the worldwide rice cultivation is performed on water logged paddy soils. The establishment of reducing conditions in the soil and across the soil-water interface not only stimulates the microbial production and release of the greenhouse gas methane. These settings also create optimal conditions for microbial iron(III) reduction and therefore saturate the system with reduced ferrous iron. Through the reduction and dissolution of ferric minerals that are characterized by their high surface activity, sorbed nutrients and contaminants (e.g. arsenic) will be mobilized and are thus available for uptake by plants. Rice plants have evolved a strategy to release oxygen from their roots in order to prevent iron toxification in highly ferrous environments. The release of oxygen to the reduced paddy soil causes ferric iron plaque formation on the rice roots and finally increases the sorption capacity for toxic metals. To this date the geochemical and microbiological processes that control the formation of iron plaque are not deciphered. It has been hypothesized that iron(II)-oxidizing bacteria play a potential role in the iron(III) mineral formation along the roots. However, not much is known about the actual processes, mineral products, and geochemical gradients that establish within the rhizosphere. In the present study we have developed a growth set-up that allows the co-cultivation of rice plants and iron(II)-oxidizing bacteria, as well as the visual observation and in situ measurement of geochemical parameters. Oxygen and dissolved iron(II) gradients have been measured using microelectrodes and show geochemical hot spots that offer optimal growth conditions for microaerophilic iron(II) oxidizers. First mineral identification attempts of iron plaque have been performed using Mössbauer spectroscopy and microscopy. The obtained results on mineraology and crystallinity have been

  2. Cattle Manure Enhances Methanogens Diversity and Methane Emissions Compared to Swine Manure under Rice Paddy.

    PubMed

    Kim, Sang Yoon; Pramanik, Prabhat; Bodelier, Paul L E; Kim, Pil Joo

    2014-01-01

    Livestock manures are broadly used in agriculture to improve soil quality. However, manure application can increase the availability of organic carbon, thereby facilitating methane (CH4) production. Cattle and swine manures are expected to have different CH4 emission characteristics in rice paddy soil due to the inherent differences in composition as a result of contrasting diets and digestive physiology between the two livestock types. To compare the effect of ruminant and non-ruminant animal manure applications on CH4 emissions and methanogenic archaeal diversity during rice cultivation (June to September, 2009), fresh cattle and swine manures were applied into experimental pots at 0, 20 and 40 Mg fresh weight (FW) ha-1 in a greenhouse. Applications of manures significantly enhanced total CH4 emissions as compared to chemical fertilization, with cattle manure leading to higher emissions than swine manure. Total organic C contents in cattle (466 g kg-1) and swine (460 g kg-1) manures were of comparable results. Soil organic C (SOC) contents were also similar between the two manure treatments, but dissolved organic C (DOC) was significantly higher in cattle than swine manure. The mcrA gene copy numbers were significantly higher in cattle than swine manure. Diverse groups of methanogens which belong to Methanomicrobiaceae were detected only in cattle-manured but not in swine-manured soil. Methanogens were transferred from cattle manure to rice paddy soils through fresh excrement. In conclusion, cattle manure application can significantly increase CH4 emissions in rice paddy soil during cultivation, and its pretreatment to suppress methanogenic activity without decreasing rice productivity should be considered. PMID:25494364

  3. Cattle Manure Enhances Methanogens Diversity and Methane Emissions Compared to Swine Manure under Rice Paddy

    PubMed Central

    Kim, Sang Yoon; Pramanik, Prabhat; Bodelier, Paul L. E.; Kim, Pil Joo

    2014-01-01

    Livestock manures are broadly used in agriculture to improve soil quality. However, manure application can increase the availability of organic carbon, thereby facilitating methane (CH4) production. Cattle and swine manures are expected to have different CH4 emission characteristics in rice paddy soil due to the inherent differences in composition as a result of contrasting diets and digestive physiology between the two livestock types. To compare the effect of ruminant and non-ruminant animal manure applications on CH4 emissions and methanogenic archaeal diversity during rice cultivation (June to September, 2009), fresh cattle and swine manures were applied into experimental pots at 0, 20 and 40 Mg fresh weight (FW) ha−1 in a greenhouse. Applications of manures significantly enhanced total CH4 emissions as compared to chemical fertilization, with cattle manure leading to higher emissions than swine manure. Total organic C contents in cattle (466 g kg−1) and swine (460 g kg−1) manures were of comparable results. Soil organic C (SOC) contents were also similar between the two manure treatments, but dissolved organic C (DOC) was significantly higher in cattle than swine manure. The mcrA gene copy numbers were significantly higher in cattle than swine manure. Diverse groups of methanogens which belong to Methanomicrobiaceae were detected only in cattle-manured but not in swine-manured soil. Methanogens were transferred from cattle manure to rice paddy soils through fresh excrement. In conclusion, cattle manure application can significantly increase CH4 emissions in rice paddy soil during cultivation, and its pretreatment to suppress methanogenic activity without decreasing rice productivity should be considered. PMID:25494364

  4. Kennedy at Rice University

    NASA Technical Reports Server (NTRS)

    1962-01-01

    President Kennedy speaks before a crowd of 35,000 people at Rice University in the football field. The following are excerpts from his speech. ' ...We set sail on his new sea because there is a new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people. ...Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. But I do say space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made with extending his writ around this globe of ours. ...There is no strife, no prejudice, no national conflict in outer space as yet. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountian? Why - 35 years ago - why fly the Atlantic? Why does Rice play Texas? We choose to go to the Moon, we choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one in which we intend to win, and the others too.'

  5. Kennedy at Rice University

    NASA Technical Reports Server (NTRS)

    1962-01-01

    President Kennedy speaks before a crowd of 35,000 people at Rice University in the football field. The following are excerpts from his speech. ' ...We set sail on his new sea because there is a new knowledge to begained, and new rights to be won, and they must be won and used for the progress of all people. Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. But I do say space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made with extending his wirt around this globe of ours. There is no strife, no prejudice, no national conflict in outer space as yet. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain? Why 35 years ago why fly the Atlantic? Why does Rice play Texas? We choose to go to the Moon, we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one in which we attend to win, and the others , too.'

  6. Outcrossing potential between U.S. red rice (Oryza sativa) and Chinese indica rice (Oryza sativa) lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice in southern U.S. rice fields remains a widespread, economically challenging problem despite nearly a decade of rice production systems that include true-breeding rice cultivars and indica-derived hybrid rice with resistance to imazethapyr. Both of these herbicide-resistant rice systems hav...

  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. Extensive sequence divergence between the reference genomes of two elite indica rice varieties Zhenshan 97 and Minghui 63.

    PubMed

    Zhang, Jianwei; Chen, Ling-Ling; Xing, Feng; Kudrna, David A; Yao, Wen; Copetti, Dario; Mu, Ting; Li, Weiming; Song, Jia-Ming; Xie, Weibo; Lee, Seunghee; Talag, Jayson; Shao, Lin; An, Yue; Zhang, Chun-Liu; Ouyang, Yidan; Sun, Shuai; Jiao, Wen-Biao; Lv, Fang; Du, Bogu; Luo, Meizhong; Maldonado, Carlos Ernesto; Goicoechea, Jose Luis; Xiong, Lizhong; Wu, Changyin; Xing, Yongzhong; Zhou, Dao-Xiu; Yu, Sibin; Zhao, Yu; Wang, Gongwei; Yu, Yeisoo; Luo, Yijie; Zhou, Zhi-Wei; Hurtado, Beatriz Elena Padilla; Danowitz, Ann; Wing, Rod A; Zhang, Qifa

    2016-08-30

    Asian cultivated rice consists of two subspecies: Oryza sativa subsp. indica and O. sativa subsp. japonica Despite the fact that indica rice accounts for over 70% of total rice production worldwide and is genetically much more diverse, a high-quality reference genome for indica rice has yet to be published. We conducted map-based sequencing of two indica rice lines, Zhenshan 97 (ZS97) and Minghui 63 (MH63), which represent the two major varietal groups of the indica subspecies and are the parents of an elite Chinese hybrid. The genome sequences were assembled into 237 (ZS97) and 181 (MH63) contigs, with an accuracy >99.99%, and covered 90.6% and 93.2% of their estimated genome sizes. Comparative analyses of these two indica genomes uncovered surprising structural differences, especially with respect to inversions, translocations, presence/absence variations, and segmental duplications. Approximately 42% of nontransposable element related genes were identical between the two genomes. Transcriptome analysis of three tissues showed that 1,059-2,217 more genes were expressed in the hybrid than in the parents and that the expressed genes in the hybrid were much more diverse due to their divergence between the parental genomes. The public availability of two high-quality reference genomes for the indica subspecies of rice will have large-ranging implications for plant biology and crop genetic improvement. PMID:27535938

  9. A Tiling Microarray Expression Analysis of Rice Chromosome 4 Suggests a Chromosome-Level Regulation of TranscriptionW⃞

    PubMed Central

    Jiao, Yuling; Jia, Peixin; Wang, Xiangfeng; Su, Ning; Yu, Shuliang; Zhang, Dongfen; Ma, Ligeng; Feng, Qi; Jin, Zhaoqing; Li, Lei; Xue, Yongbiao; Cheng, Zhukuan; Zhao, Hongyu; Han, Bin; Deng, Xing Wang

    2005-01-01

    The complete genome sequence of cultivated rice (Oryza sativa) provides an unprecedented opportunity to understand the biology of this model cereal. An essential and necessary step in this effort is the determination of the coding information and expression patterns of each sequenced chromosome. Here, we report an analysis of the transcriptional activity of rice chromosome 4 using a tiling path microarray based on PCR-generated genomic DNA fragments. Six representative rice organ types were examined using this microarray to catalog the transcribed regions of rice chromosome 4 and to reveal organ- and developmental stage–specific transcription patterns. This analysis provided expression support for 82% of the gene models in the chromosome. Transcriptional activities in 1643 nonannotated regions were also detected. Comparison with cytologically defined chromatin features indicated that in juvenile-stage rice the euchromatic region is more actively transcribed than is the transposon-rich heterochromatic portion of the chromosome. Interestingly, increased transcription of transposon-related gene models in certain heterochromatic regions was observed in mature-stage rice organs and in suspension-cultured cells. These results suggest a close correlation between transcriptional activity and chromosome organization and the developmental regulation of transcription activity at the chromosome level. PMID:15863518

  10. African-Americans and Alzheimer's

    MedlinePlus

    ... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

  11. Processing Conditions, Rice Properties, Health and Environment

    PubMed Central

    Roy, Poritosh; Orikasa, Takahiro; Okadome, Hiroshi; Nakamura, Nobutaka; Shiina, Takeo

    2011-01-01

    Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR), germinated brown rice (GBR) and partially-milled rice (PMR) contains more health beneficial food components compared to the well milled rice (WMR). Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR) seems to be relatively prone to arsenic contamination compared to that of untreated rice, if contaminated water is used for parboiling and cooking. A change in consumption patterns from PBR to untreated rice (non-parboiled), and WMR to PMR or BR may conserve about 43–54 million tons of rice and reduce the risk from arsenic contamination in the arsenic prone area. This study also reveals that a change in rice consumption patterns not only supply more food components but also reduces environmental loads. A switch in production and consumption patterns would improve food security where food grains are scarce, and provide more health beneficial food components, may prevent some diseases and ease the burden on the Earth. However, motivation and awareness of the environment and health, and even a nominal incentive may require for a method switching which may help in building a sustainable society. PMID:21776212

  12. Molecular dynamics of interactions of rice with rice blast and sheath blight pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to develop the molecular strategies to control rice (Oryzae sativa) diseases, molecular interactions of rice with rice blast [Magnaporthe oryzae, formerly (Magnaporthe grisea] and sheath blight (Rhizoctonia solani) fungi were analyzed. The interaction of rice with M. oryzae follows a b...

  13. The impact of planting date on management of the rice water weevil in Louisiana rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rice water weevil, Lissorhoptrus oryzophilus, is the most destructive insect pest of rice in the United States. Early planting of rice to avoid damaging infestations of the rice water weevil has long been suggested as a management tactic. A five-year study was conducted to characterize the influ...

  14. Diversity of global rice markets and the science required for consumer-targeted rice breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of different quality traits that make up the rice grain and obtain a full picture of rice quality demographics. Rice ...

  15. Genetic diversity for rice grain mineral concentrations observed among genetically and geographically giverse rice accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With about half of the world’s people dependent on rice as their main food source, improving the nutritional value of rice could have major impact on human health. While rice in the USA is often artificially fortified, natural enhancement of the rice grain’s nutritional value, i.e. from genetic impr...

  16. Volatiles induction in rice stink bug host grasses and rice plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice stink bug (RSB), Oebalus pugnax F., is an important pest of heading rice in the United States. Little is known about plant volatiles production following herbivory by the rice stink bug. RSB feeding induced volatiles production in different RSB host grasses and rice varieties, and may help expl...

  17. Music Videos and Sexual Risk in African American Adolescent Girls: Gender, Power and the Need for Media Literacy

    ERIC Educational Resources Information Center

    Robillard, Alyssa

    2012-01-01

    Background: Music videos contain sexual content often reflecting women as promiscuous, submissive, or passive. Few studies have examined gender- and sex-related attitudes in African American females, particularly across genres of music videos. Purpose: Using constructs from Cultivation Theory, Theory of Gender and Power and Social Cognitive…

  18. The Struggles over African Languages

    ERIC Educational Resources Information Center

    Maseko, Pam; Vale, Peter

    2016-01-01

    In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

  19. Psychological Misdiagnosis of African Americans.

    ERIC Educational Resources Information Center

    Garretson, Deborah J.

    1993-01-01

    Reviews historical and current problems with making accurate psychological diagnoses of African Americans. Suggests that misdiagnosis is strongly related to pathologization of African-American culture itself. Explores diagnostic process, stereotypes of African-American psychopathology, cultural differences in values and life stressors, and…

  20. Effects of cultivation frequency on sugarcane yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the number of cultivations during one or more years of a four year crop cycle reduces production expenses and could increase profitability if yields are not adversely affected. This study was initiated to determine the effects of cultivation on yields of sugarcane grown on a clay soil both ...

  1. Effects of cultivation frequency on sugarcane yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the number of cultivations during one or more years of a four year crop cycle may potentially reduce production expenses for Louisiana sugarcane growers. This study was initiated to determine the effects of cultivation on yields of sugarcane grown on a clay soil both on an annual basis and ...

  2. Narcolepsy in African Americans

    PubMed Central

    Kawai, Makoto; O'Hara, Ruth; Einen, Mali; Lin, Ling; Mignot, Emmanuel

    2015-01-01

    Study Objectives: Although narcolepsy affects 0.02–0.05% of individuals in various ethnic groups, clinical presentation in different ethnicities has never been fully characterized. Our goal was to study phenotypic expression across ethnicities in the United States. Design/Setting: Cases of narcolepsy from 1992 to 2013 were identified from searches of the Stanford Center for Narcolepsy Research database. International Classification of Sleep Disorders, Third Edition diagnosis criteria for type 1 and type 2 narcolepsy were used for inclusion, but subjects were separated as with and without cataplexy for the purpose of data presentation. Information extracted included demographics, ethnicity and clinical data, HLA-DQB1*06:02, polysomnography (PSG), multiple sleep latency test (MSLT) data, and cerebrospinal fluid (CSF) hypocretin-1 level. Patients: 182 African-Americans, 839 Caucasians, 35 Asians, and 41 Latinos with narcolepsy. Results: Sex ratio, PSG, and MSLT findings did not differ across ethnicities. Epworth Sleepiness Scale (ESS) score was higher and age of onset of sleepiness earlier in African Americans compared with other ethnicities. HLA-DQB1*06:02 positivity was higher in African Americans (91.0%) versus others (76.6% in Caucasians, 80.0% in Asians, and 65.0% in Latinos). CSF hypocretin-1 level, obtained in 222 patients, was more frequently low (≤ 110 pg/ml) in African Americans (93.9%) versus Caucasians (61.5%), Asians (85.7%) and Latinos (75.0%). In subjects with low CSF hypocretin-1, African Americans (28.3%) were 4.5 fold more likely to be without cataplexy when compared with Caucasians (8.1%). Conclusions: Narcolepsy in African Americans is characterized by earlier symptom onset, higher Epworth Sleepiness Scale score, higher HLA-DQB1*06:02 positivity, and low cerebrospinal fluid hypocretin-1 level in the absence of cataplexy. In African Americans, more subjects without cataplexy have type 1 narcolepsy. Citation: Kawai M, O'Hara R, Einen M, Lin L

  3. GENE FLOW BETWEEN RED RICE AND RICE IN HERBICIDE RESISTANT RICE FIELDS: EVALUATING RISKS AND MANAGEMENT OPTIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imidazolinone (IMI)-resistant rice cultivars have been increasingly adopted in the southern U.S. since their initial introduction in 2002, largely due to the newly acquired control of red rice that is now possible in these systems. It is estimated that IMI rice is being grown on 20 to 25% of the ac...

  4. Reducing CH4 emission from rice paddy fields by altering water management

    NASA Astrophysics Data System (ADS)

    Sudo, S.; Itoh, M.

    2010-12-01

    Percentage of atmospheric methane emitted form rice paddy is estimated at 60Tg/yr (20 - 100Tg/yr) which is near 10% of total global methane emission of 535Tg/yr (410 - 660Tg) (IPCC(1995), and which is near 30% of anthropogenic CH4 emission. Thus, mitigation of CH4 emission is urgently required. CH4 in paddy soil is emanated by the activities of anaerobic bacteria which is called methane producer through reduction of CO2 or decomposition of acetic acid, and it is transported to atmosphere through soil or paddy water surface. It is effective to control methane emission from rice paddy that period is extended on intermittent drainage, composted rice straw is incorporated as fertilizer instead of flesh one, or other. However, empirical approach of these kinds of experiments had not been sufficient because such a kind of experiment required significant times and efforts. In this study, we conducted demonstrative experiments to verify the effects of water management method differences in order to reduce CH4 emission from rice paddy at 9 experimental sites in 8 prefectures. In this, we used new gas analyzer which can measure CH4, CO2 and N2O at once developed by National Institute for Agro-Environmental Sciences (NIAES), Japan. In this report, we show the results in two years of this study. 'Nakaboshi' (mid-season-drainage) is one of cultivation methods in rice paddy that surface water in paddy field is once drained for about 10 days and the field is maintained like upland field to give adequate stress to rice plant for better harvest qualities and yields. Our targeted evaluation was dependencies of Nakaboshi periods lengths and Nakaboshi periods to CH4 emission reduction amounts for total cultivation periods within harvest yield maintained. The longer length of Nakaboshi period was extended, the lesser CH4 emitted even after when Nakaboshi period lasted, as a whole. In some cases, for example in Kagoshima, exceptional phenomena of that significant high emission were

  5. Fingerprint of Seasonal Relative humidity in Rice (Oryza sativa L.): Potential for Paleoclimate Archive

    NASA Astrophysics Data System (ADS)

    Kaushal, R.; Ghosh, P.

    2015-12-01

    Seasonal variability of relative humidity (RH) condition during southwest monsoon (SWM) is strongly related with availability of moisture for rainfall over the continental region. There are ongoing efforts to reconstruct the past monsoonal condition based on geochemical and isotopic records as proxies [1]. However, limited archives have been successfully retrieved for reconstructing moisture condition during SWM [2]. Potential of plants as climate archives and the mechanism involved in transfer of climate signature to the stable isotope composition of oxygen (δ18O) has been demonstarted successfully [3]. Here we are introducing δ18O of rice grain bulk organic matter (δ18OOM) as a new proxy for precise determination of RH during SWM. Rice is a seasonal crop and widely cultivated over the Indian subcontinent during SWM. Here we present δ18OOM of rice grains collected from 15 locations from different climatic zones over the Indian subcontinent, ranging from semi-arid to humid-perhumid. These samples were collected from the harvest of the crop grown at the time of SWM for the period 2012-2014. Each of these climatic zones are characterized by unique range of RH values, which is expected to leave distinct oxygen isotopic signature in the rice grain OM. We compared the δ18OOM values with δ18O of precipitation water, RH and temperature during the period of cultivation. Precipitation δ18O values were obtained from were obtained from OPIC [4]. Our observations document a significant relationship between δ18OOM and RH (R2 =0.62, p<0.001). When the RH level fluctuated from 65% to 88%, δ18OOM tended to vary between 31.5 ‰ to 15.4‰. However, the humid regions with rainfed crop showed significant relationship between δ18OOM and precipitation δ18O. Remaining stations being fed by the both rain and irrigation from river/ groundwater, dampen the rainfall isotope signature in δ18OOM. This approach can be extended in deriving RH of regions of rice cultivation by

  6. The Genetic Structure and History of Africans and African Americans

    PubMed Central

    Tishkoff, Sarah A.; Reed, Floyd A.; Friedlaender, Françoise R.; Ehret, Christopher; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril B.; Awomoyi, Agnes A.; Bodo, Jean-Marie; Doumbo, Ogobara; Ibrahim, Muntaser; Juma, Abdalla T.; Kotze, Maritha J.; Lema, Godfrey; Moore, Jason H.; Mortensen, Holly; Nyambo, Thomas B.; Omar, Sabah A.; Powell, Kweli; Pretorius, Gideon S.; Smith, Michael W.; Thera, Mahamadou A.; Wambebe, Charles; Weber, James L.; Williams, Scott M.

    2010-01-01

    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies. PMID:19407144

  7. Geographic information system-based identification of suitable cultivation sites for wood-cultivated ginseng.

    PubMed

    Beon, Mu Sup; Park, Jun Ho; Kang, Hag Mo; Cho, Sung Jong; Kim, Hyun

    2013-10-01

    Wood-cultivated ginseng, including roots in its dried form, is produced in forest land without using artificial facilities such as light barriers. To identify suitable sites for the propagation of wood-cultivated ginseng, factor combination technique (FCT) and linear combination technique (LCT) were used with geographic information system and the results were superimposed onto an actual wood-cultivated ginseng plantation. The LCT more extensively searched for suitable sites of cultivation than that by the FCT; further, the LCT probed wide areas considering the predominance of precipitous mountains in Korea. In addition, the LCT showed the much higher degree of overlap with the actual cultivation sites; therefore, the LCT more comprehensively reflects the cultivator's intention for site selection. On the other hand, the inclusion of additional factors for the selection of suitable cultivation sites and experts' opinions may enhance the effectiveness and accuracy of the LCT for site application. PMID:24235864

  8. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season.

    PubMed

    Pramanik, Prabhat; Haque, Md Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2014-08-15

    Combination of leguminous and non-leguminous plant residues are preferably applied in rice paddy soils to increase the rate of organic matter mineralization and to improve plant growth. However, organic matter addition facilitates methane (CH4) emission from rice paddy soil. Mineralization of organic nitrogen (N) increases NO3-N concentrations in soil, which are precursors for the formation of nitrous oxide (N2O). However, N2O is a minor greenhouse gas emitted from submerged rice field and hence is not often considered during calculation of total global warming potential (GWP) during rice cultivation. The hypothesis of this study was that fluxes of N2O emissions might be changed after removal of flooded water from rice field and the effect of cover crops on N2O emissions in the fallow season might be interesting. However, the effects of N-rich plant residues on N2O emission rates in the fallow season and its effect on annual GWP were not studied before. In this experiment, combination of barley (non-leguminous) and hairy vetch (leguminous) biomasses were applied at 9 Mg ha(-1) and 27 Mg ha(-1) rates in rice paddy soil. Cover crop application significantly increased CH4 emission flux while decreased N2O emissions during rice cultivation. The lowest N2O emission was observed in 27 Mg ha(-1) cover crop treated plots. Cover crop applications increased N contents in soil aggregates especially in smaller aggregates (<250 μm), and that proportionately increased the N2O emission potentials of these soil aggregates. Fluxes of N2O emissions in the fallow season were influenced by the N2O emission potentials of soil aggregates and followed opposite trends as those observed during rice cultivation. Therefore, it could be concluded that the doses of cover crop applications for rice cultivation should not be optimized considering only CH4, but N2O should also be considered especially for fallow season to calculate total GWP. PMID:24880551

  9. Molecular analysis of bacterial community structures in paddy soils for environmental risk assessment with two varieties of genetically modified rice, Iksan 483 and Milyang 204.

    PubMed

    Kim, Min-Cheol; Ahn, Jae-Hyung; Shin, Hye-Chul; Kim, Taesung; Ryu, Tae-Hun; Kim, Dong-Hern; Song, Hong-Gyu; Lee, Geon Hyoung; Ka, Jong-Ok

    2008-02-01

    The impacts of planted transgenic rice varieties on bacterial communities in paddy soils were monitored using both cultivation and molecular methods. The rice field plot consisted of eighteen subplots planted with two genetically modified (GM) rice and four non-GM rice plants in three replicates. Analysis with denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes revealed that the bacterial community structures were quite similar to each other in a given month, suggesting that there were no significant differences in bacterial communities between GM and non- GM rice soils. The bacterial community structures appeared to be generally stable with the seasons, as shown by a slight variation of microbial population levels and DGGE banding patterns over the year. Comparison analysis of 16S rDNA clone libraries constructed from soil bacterial DNA showed that there were no significant differences between GM and non-GM soil libraries but revealed seasonal differences of phyla distribution between August and December. The composition profile of phospholipid fatty acids (PLFA) between GM and non-GM soils also was not significantly different to each other. When soil DNAs were analyzed with PCR by using primers for the bar gene, which was introduced into GM rice, positive DNA bands were found in October and December soils. However, no bar gene sequence was detected in PCR analysis with DNAs extracted from both cultured and uncultured soil bacterial fractions. The result of this study suggested that, in spite of seasonal variations of bacterial communities and persistence of the bar gene, the bacterial communities of the experimental rice field were not significantly affected by cultivation of GM rice varieties. PMID:18309263

  10. An Overview of Talent Cultivation Models in Foreign Vocational Colleges

    ERIC Educational Resources Information Center

    Wang, Youhua

    2010-01-01

    A talent cultivation model refers to a model of the construction and operation of the cultivation process adopted by a school to achieve its cultivation objectives. Four models, with their differences and similarities, are introduced in this paper.

  11. Rice disease research in organic production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic rice production has increased significantly in the U. S. with 35,000 acres currently under production. Texas organic rice acreage has been increasing steadily over the last 10 years with acreage in 2009 reaching 16,000, accounting for approximately 10% of the total Texas rice acreage. Contro...

  12. Is ALL Rice Bran Created Equal?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of whole grain rice is increasing in the U.S. This increase is likely due to increased consumer awareness of the importance of whole grains in the diet. Whole grain rice is superior nutritionally compared to milled rice because, except for carbohyrates, it contains more phytochemicals an...

  13. Understanding rice heterosis using deep sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterosis is a complex biological phenomenon where the offspring show better performance compared to the inbred parents. Although rice breeders have used heterosis in hybrid rice production for nearly 40 years, the genetic and molecular mechanism underlying the heterosis in rice is still poorly und...

  14. Rice functionality, starch structure and the genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Through collaborative efforts among USDA scientists at Beaumont, Texas, we have gained in-depth knowledge of how rice functionality, i.e. the texture of the cooked rice, rice processing properties, and starch gelatinization temperature, are associated with starch-synthesis genes and starch structure...

  15. SHEATH BLIGHT RESISTANCE IN SOUTHERN RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheath blight is a serious fungal disease problem in southern US rice production, making it necessary for rice farmers to diligently use fungicides for its control. There are no long grain rice varieties adapted to commercial production in the southern US that have adequate resistance to sheath bli...

  16. U.S. Rice: Enhancing human health.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A vision of the U.S. rice industry is to improve human health through the development of germplasm and technologies for products that capture the unique nutritional benefits of the rice grain. This paper gives an overview of U.S. rice production and markets. New product trends and introductions in...

  17. New market opportunities for rice grains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding efforts for rice have been focusing on increasing yield and improving quality (milling yield and grain quality), while maintaining cooked rice sensory properties to meet consumer preferences. These breeding targets will no doubt continue as the main foci for the rice industry. However, the ...

  18. Arsenic in soil and irrigation water affects arsenic uptake by rice: complementary insights from field and pot studies.

    PubMed

    Dittmar, Jessica; Voegelin, Andreas; Maurer, Felix; Roberts, Linda C; Hug, Stephan J; Saha, Ganesh C; Ali, M Ashraf; Badruzzaman, A Borhan M; Kretzschmar, Ruben

    2010-12-01

    Groundwater rich in arsenic (As) is extensively used for dry season boro rice cultivation in Bangladesh, leading to long-term As accumulation in soils. This may result in increasing levels of As in rice straw and grain, and eventually, in decreasing rice yields due to As phytotoxicity. In this study, we investigated the As contents of rice straw and grain over three consecutive harvest seasons (2005-2007) in a paddy field in Munshiganj, Bangladesh, which exhibits a documented gradient in soil As caused by annual irrigation with As-rich groundwater since the early 1990s. The field data revealed that straw and grain As concentrations were elevated in the field and highest near the irrigation water inlet, where As concentrations in both soil and irrigation water were highest. Additionally, a pot experiment with soils and rice seeds from the field site was carried out in which soil and irrigation water As were varied in a full factorial design. The results suggested that both soil As accumulated in previous years and As freshly introduced with irrigation water influence As uptake during rice growth. At similar soil As contents, plants grown in pots exhibited similar grain and straw As contents as plants grown in the field. This suggested that the results from pot experiments performed at higher soil As levels can be used to assess the effect of continuing soil As accumulation on As content and yield of rice. On the basis of a recently published scenario of long-term As accumulation at the study site, we estimate that, under unchanged irrigation practice, average grain As concentrations will increase from currently ∼0.15 mg As kg(-1) to 0.25-0.58 mg As kg(-1) by the year 2050. This translates to a 1.5-3.8 times higher As intake by the local population via rice, possibly exceeding the provisional tolerable As intake value defined by FAO/WHO. PMID:21043519

  19. Monitoring of rice cropping intensity in the upper Mekong Delta, Vietnam using time-series MODIS data

    NASA Astrophysics Data System (ADS)

    Chen, C. F.; Son, N. T.; Chang, L. Y.

    2012-01-01

    Information on rice growing areas is important for policymakers to devise agricultural plans. This research explores the monitoring of rice cropping intensity in the upper Mekong Delta, Vietnam (from 2001 to 2007) using time-series MODIS NDVI 250-m data. Data processing includes three steps: (1) noise is filtered from the time-series NDVI data using empirical mode decomposition (EMD); (2) endmembers are extracted from the filtered time-series data and trained in a linear mixture model (LMM) for classification of rice cropping systems; and (3) classification results are verified by comparing them with the ground-truth and statistical data. The results indicate that EMD is a good filter for noise removal from the time-series data. The classification results confirm the validity of LMM, giving an overall accuracy of 90.1% and a Kappa coefficient of 0.7. The lowest producer and user accuracies were associated with single crop rain-fed rice class due to the mixed pixel problems. A strong yearly correlation at the district level was revealed in the MODIS-derived areas (R2 ⩾ 0.9). Investigation of interannual changes in rice cropping intensity from 2001 to 2007 showed a remarkable conversion from double to triple crop irrigated rice from 2001 to 2003, especially in the Thoai Son and Phu Tan districts. A big conversion from triple crop rice back to double crop rice cultivation was also observed in Phu Tan from 2005 to 2006. These changes were verified by visual interpretation of Landsat images and examination of NDVI profiles.

  20. Genetic Diversity Analysis Reveals that Geographical Environment Plays a More Important Role than Rice Cultivar in Villosiclava virens Population Selection

    PubMed Central

    Wang, Fei; Zhang, Shu; Liu, Mei-Gang; Lin, Xian-Song; Liu, Hui-Jiang; Peng, You-Liang; Lin, Yang; Huang, Jun-Bin

    2014-01-01

    Rice false smut caused by Villosiclava virens is an economically important disease of grains worldwide. The genetic diversity of 153 isolates from six fields located in Wuhan (WH), Yichang Wangjia (YCW), Yichang Yaohe (YCY), Huanggang (HG), Yangxin (YX), and Jingzhou (JZ) in Hubei province of China were phylogenetically analyzed to evaluate the influence of environments and rice cultivars on the V. virens populations. Isolates (43) from Wuhan were from two rice cultivars, Wanxian 98 and Huajing 952, while most of the other isolates from fields YCW, YCY, HG, YX, and JZ originated from different rice cultivars with different genetic backgrounds. Genetic diversity of isolates was analyzed using random amplified polymorphic DNA (RAPD) and single-nucleotide polymorphisms (SNP). The isolates from the same cultivars in Wuhan tended to group together, indicating that the cultivars had an important impact on the fungal population. The 110 isolates from individual fields tended to cluster according to geographical origin. The values of Nei's gene diversity (H) and Shannon's information index (I) showed that the genetic diversity among isolates was higher between than within geographical populations. Furthermore, mean genetic distance between groups (0.006) was higher than mean genetic distance within groups (0.0048) according to MEGA 5.2. The pairwise population fixation index (FST) values also showed significant genetic differentiation between most populations. Higher genetic similarity of isolates from individual fields but different rice cultivars suggested that the geographical factor played a more important role in the selection of V. virens isolates than rice cultivars. This information could be used to improve the management strategy for rice false smut by adjusting the cultivation measures, such as controlling fertilizer, water, and planting density, in the rice field to change the microenvironment. PMID:24584249

  1. Genetic diversity analysis reveals that geographical environment plays a more important role than rice cultivar in Villosiclava virens population selection.

    PubMed

    Wang, Fei; Zhang, Shu; Liu, Mei-Gang; Lin, Xian-Song; Liu, Hui-Jiang; Peng, You-Liang; Lin, Yang; Huang, Jun-Bin; Luo, Chao-Xi

    2014-05-01

    Rice false smut caused by Villosiclava virens is an economically important disease of grains worldwide. The genetic diversity of 153 isolates from six fields located in Wuhan (WH), Yichang Wangjia (YCW), Yichang Yaohe (YCY), Huanggang (HG), Yangxin (YX), and Jingzhou (JZ) in Hubei province of China were phylogenetically analyzed to evaluate the influence of environments and rice cultivars on the V. virens populations. Isolates (43) from Wuhan were from two rice cultivars, Wanxian 98 and Huajing 952, while most of the other isolates from fields YCW, YCY, HG, YX, and JZ originated from different rice cultivars with different genetic backgrounds. Genetic diversity of isolates was analyzed using random amplified polymorphic DNA (RAPD) and single-nucleotide polymorphisms (SNP). The isolates from the same cultivars in Wuhan tended to group together, indicating that the cultivars had an important impact on the fungal population. The 110 isolates from individual fields tended to cluster according to geographical origin. The values of Nei's gene diversity (H) and Shannon's information index (I) showed that the genetic diversity among isolates was higher between than within geographical populations. Furthermore, mean genetic distance between groups (0.006) was higher than mean genetic distance within groups (0.0048) according to MEGA 5.2. The pairwise population fixation index (FST) values also showed significant genetic differentiation between most populations. Higher genetic similarity of isolates from individual fields but different rice cultivars suggested that the geographical factor played a more important role in the selection of V. virens isolates than rice cultivars. This information could be used to improve the management strategy for rice false smut by adjusting the cultivation measures, such as controlling fertilizer, water, and planting density, in the rice field to change the microenvironment. PMID:24584249

  2. The life cycle of rice: LCA of alternative agri-food chain management systems in Vercelli (Italy).

    PubMed

    Blengini, Gian Andrea; Busto, Mirko

    2009-03-01

    The Vercelli rice district in northern Italy plays a key role in the agri-food industry in a country which accounts for more than 50% of the EU rice production and exports roughly 70%. However, although wealth and jobs are created, the sector is said to be responsible for environmental impacts that are increasingly being perceived as topical. As a complex and comprehensive environmental evaluation is necessary to understand and manage the environmental impact of the agri-food chain, the Life Cycle Assessment (LCA) methodology has been applied to the rice production system: from the paddy field to the supermarket. The LCA has pointed out the magnitude of impact per kg of delivered white milled rice: a CO2eq emission of 2.9 kg, a primary energy consumption of 17.8 MJ and the use of 4.9 m3 of water for irrigation purposes. Improvement scenarios have been analysed considering alternative rice farming and food processing methods, such as organic and upland farming, as well as parboiling. The research has shown that organic and upland farming have the potential to decrease the impact per unit of cultivated area. However, due to the lower grain yields, the environmental benefits per kg of the final products are greatly reduced in the case of upland rice production and almost cancelled for organic rice. LCA has proved to be an effective tool for understanding the eco-profile of Italian rice and should be used for transparent and credible communication between suppliers and their customers. PMID:19046619

  3. The Other African Americans.

    ERIC Educational Resources Information Center

    Matory, J. Lorand

    Black North America is ethnically and culturally diverse. It contains many groups who do not call themselves or have not always called themselves "Negro,""Black,""African-American," and so forth, such as Louisiana Creoles of color and many of the Indian tribes east of the Mississippi. There are also numerous North American ethnic groups of African…

  4. African American rhinoplasty.

    PubMed

    Boyette, Jennings R; Stucker, Fred J

    2014-08-01

    Rhinoplasty in patients of African descent requires a patient-specific approach, because the goals and ideal proportions differ from the white nose. This article discusses approaches to surgical correction of common anatomic variations. In addition, common pitfalls are outlined. PMID:25049123

  5. Elective: African Literature.

    ERIC Educational Resources Information Center

    Jenkins, Kenneth V.

    The make-up of a course in African literature for high school students is discussed. It is pointed out that the course can be constructed on already familiar lines. High school students will be able to describe clearly, for example, the relationship between environment and character or the dilemma of characters caught between traditional values…

  6. Transgenic indica rice lines, expressing Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1), exhibit enhanced resistance to major pathogens.

    PubMed

    Sadumpati, Vijayakumar; Kalambur, Muralidharan; Vudem, Dashavantha Reddy; Kirti, Pulugurtha Bharadwaja; Khareedu, Venkateswara Rao

    2013-07-10

    Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1) has been introduced into commercial indica rice varieties by Agrobacterium-mediated genetic transformation. Transgenic rice plants were regenerated from the phosphinothricin-resistant calli obtained after co-cultivation with Agrobacterium strain LBA4404 harbouring Ti plasmid pSB111-bar-BjNPR1. Molecular analyses confirmed the stable integration and expression of BjNPR1 in various transgenic rice lines. Transgenes NPR1 and bar were stably inherited and disclosed co-segregation in subsequent generations in a Mendelian fashion. Homozygous transgenic rice lines expressing BjNPR1 protein displayed enhanced resistance to rice blast, sheath blight and bacterial leaf blight diseases. Rice transformants with higher levels of NPR1 revealed notable increases in plant height, panicle length, flag-leaf length, number of seeds/panicle and seed yield/plant as compared to the untransformed plants. The overall results amply demonstrate the profound impact of BjNPR1 in imparting resistance against major pathogens of rice. The multipotent BjNPR1, as such, seems promising as a prime candidate gene to fortify crop plants with durable resistance against various pathogens. PMID:23664883

  7. Alternate Wetting and Drying as an Effective Management Practice to Reduce Methane in Arkansas Rice Production

    NASA Astrophysics Data System (ADS)

    Runkle, B.; Smith, S. F.; Suvocarev, K.; Reba, M. L.

    2015-12-01

    Approximately 15% of the global 308 Tg CH4 emitted by anthropogenic sources is currently attributed to rice cultivation. Arkansas, the leading state in rice cultivation, produces over 42% of the total rice and represents over 43% of total land planted to rice in the US. Although rice production is generally water-intensive, some rice producers have adopted a conservation practice, 'Alternate Wetting and Drying' (AWD), in which the flood is released periodically during the growing season. In addition, implementing AWD can reduce CH4 emissions though the introduction of aerobic conditions. To assess the magnitude of this reduction, conventionally flooded (CONV) and AWD fields were identically instrumented for the 2015 season and fluxes of CH4 were measured with an open path IRGA. Other biophysical variables were monitored to determine the relative dominance of potential drivers. Half-hourly CH4 fluxes from the AWD and CONV fields during their similar initial flood (DOY 138-161) were well correlated (R2 = 0.762), indicating similar mechanisms controlling CH4 emissions in both fields. After the initial drydown event in the AWD field (162 DOY), daily median CH4 fluxes continued to rise to 7.80 mg CH4 m-2 h-1 on 163 DOY before subsiding to a local minimum of 0.162 mg CH4 m-2 h-1 on 171 DOY. Daily median CH4 fluxes between 9.24 and 16.0 mg CH4 m-2 h-1 were observed in the CONV field during this same period. Cumulative emissions from both fields following the drydown event and prior to rewetting demonstrated a reduction in CH4 emissions by the AWD treatment by 82%. The substantial decrease in CH4 emissions by AWD in the early growing season supports and expands upon previous chamber-based research and offers strong evidence for the efficacy of AWD in reducing CH4 emissions in AR rice production. The presentation will also assess the latter portion of the growing season, currently underway, and will provide process-based relationships between biophysical parameters and CH

  8. Changes in the concentration of fumonisins in forage rice during the growing period, differences among cultivars and sites, and identification of the causal fungus.

    PubMed

    Uegaki, Ryuichi; Tohno, Masanori; Yamamura, Kohji; Tsukiboshi, Takao

    2014-04-16

    To clarify the changes in rice fumonisin (FUM) concentrations, we conducted field cultivation of 10 forage rice cultivars and inoculation with fumonisin-producing fungal isolates. We cultivated 10 forage rice cultivars at the NARO Institute of Livestock and Grassland Science and one cultivar at two additional farmland sites in Japan in 2011 and 2012. Fusarium fujikuroi, which primarily infects plants shortly after heading, was inoculated on rice just after heading, and we sampled heads at the yellow-ripe and full-ripe stages to assess FUM concentrations. We found differences among cultivars in the FUM concentration and differences among the sites for the same cultivar, but no cultivar had high levels in leaves and stems. Fusarium fujikuroi was the main fumonisin producer. The FUM concentration in heads increases from <1 to 4760 μg/kg DM after the yellow-ripe stage. To control FUM levels, it is necessary to select low-FUM cultivars and manage the cultivation environment. PMID:24628734

  9. Impacts of climate change on paddy rice yield in a temperate climate.

    PubMed

    Kim, Han-Yong; Ko, Jonghan; Kang, Suchel; Tenhunen, John

    2013-02-01

    The crop simulation model is a suitable tool for evaluating the potential impacts of climate change on crop production and on the environment. This study investigates the effects of climate change on paddy rice production in the temperate climate regions under the East Asian monsoon system using the CERES-Rice 4.0 crop simulation model. This model was first calibrated and validated for crop production under elevated CO2 and various temperature conditions. Data were obtained from experiments performed using a temperature gradient field chamber (TGFC) with a CO2 enrichment system installed at Chonnam National University in Gwangju, Korea in 2009 and 2010. Based on the empirical calibration and validation, the model was applied to deliver a simulated forecast of paddy rice production for the region, as well as for the other Japonica rice growing regions in East Asia, projecting for years 2050 and 2100. In these climate change projection simulations in Gwangju, Korea, the yield increases (+12.6 and + 22.0%) due to CO2 elevation were adjusted according to temperature increases showing variation dependent upon the cultivars, which resulted in significant yield decreases (-22.1% and -35.0%). The projected yields were determined to increase as latitude increases due to reduced temperature effects, showing the highest increase for any of the study locations (+24%) in Harbin, China. It appears that the potential negative impact on crop production may be mediated by appropriate cultivar selection and cultivation changes such as alteration of the planting date. Results reported in this study using the CERES-Rice 4.0 model demonstrate the promising potential for its further application in simulating the impacts of climate change on rice production from a local to a regional scale under the monsoon climate system. PMID:23504792

  10. Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches

    PubMed Central

    Kumar, Arvind; Dixit, Shalabh; Ram, T.; Yadaw, R. B.; Mishra, K. K.; Mandal, N. P.

    2014-01-01

    The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1, qDTY 2.2, qDTY 3.1, qDTY 3.2, qDTY 6.1, and qDTY 12.1) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding. PMID:25205576

  11. 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

  12. Extensive sequence variation in rice blast resistance gene Pi54 makes it broad spectrum in nature

    PubMed Central

    Thakur, Shallu; Singh, Pankaj K.; Das, Alok; Rathour, R.; Variar, M.; Prashanthi, S. K.; Singh, A. K.; Singh, U. D.; Chand, Duni; Singh, N. K.; Sharma, Tilak R.

    2015-01-01

    Rice blast resistant gene, Pi54 cloned from rice line, Tetep, is effective against diverse isolates of Magnaporthe oryzae. In this study, we prospected the allelic variants of the dominant blast resistance gene from a set of 92 rice lines to determine the nucleotide diversity, pattern of its molecular evolution, phylogenetic relationships and evolutionary dynamics, and to develop allele specific markers. High quality sequences were generated for homologs of Pi54 gene. Using comparative sequence analysis, InDels of variable sizes in all the alleles were observed. Profiling of the selected sites of SNP (Single Nucleotide Polymorphism) and amino acids (N sites ≥ 10) exhibited constant frequency distribution of mutational and substitutional sites between the resistance and susceptible rice lines, respectively. A total of 50 new haplotypes based on the nucleotide polymorphism was also identified. A unique haplotype (H_3) was found to be linked to all the resistant alleles isolated from indica rice lines. Unique leucine zipper and tyrosine sulfation sites were identified in the predicted Pi54 proteins. Selection signals were observed in entire coding sequence of resistance alleles, as compared to LRR domains for susceptible alleles. This is a maiden report of extensive variability of Pi54 alleles in different landraces and cultivated varieties, possibly, attributing broad-spectrum resistance to Magnaporthe oryzae. The sequence variation in two consensus region: 163 and 144 bp were used for the development of allele specific DNA markers. Validated markers can be used for the selection and identification of better allele(s) and their introgression in commercial rice cultivars employing marker assisted selection. PMID:26052332

  13. Rice bran proteins: properties and food uses.

    PubMed

    Prakash, J

    1996-07-01

    Rice bran, a good source of protein and fat, is at present underutilized as a food material. The potential of producing rice bran at the global level is 27.3 million t. The presence of enzyme lipase in rice bran causes rapid deterioration of oil to free fatty acids and glycerol. Various stabilization techniques involving heat treatment, low-temperature storage, chemical treatment, control of relative humidity during storage, and simultaneous milling and extraction were evolved to inactivate lipase. Multiple forms of rice bran lipase have been identified. Fractional classification of proteins reveals a high percentage of albumins and globulins. Proteins can be extracted from full-fat or defatted rice bran by alkaline extraction and acid or heat precipitation. Extraction procedures influence the protein content of concentrates, which ranged from 19.4 to 76.1% in concentrates from full-fat rice bran and 17.5 to 85.0% in concentrates from defatted rice bran. The PER of rice bran ranges from 1.59 to 2.04 and that of protein concentrates from 1.99 to 2.19. Available lysine contents of protein concentrates ranged from 54 to 58.8%. The essential amino acid profiles of protein concentrates indicate that threonine and isoleucine are limiting amino acids. Various functional properties of rice bran protein concentrates have also been investigated that are known to be influenced by drying technique and stabilization treatment of rice bran. Rice bran has been used in food as full-fat rice bran, defatted rice bran, and in the form of rice bran oil and protein concentrates. Full-fat and defatted rice bran have been used in bakery products, breakfast cereals, wafers, as a protein supplement, binder ingredients for meats and sausages, and as a beverage base. Incorporation of protein concentrates have been studied in bread, beverages, confections, and weaning foods. PMID:8841730

  14. African Ancestry Is Associated with Asthma Risk in African Americans

    PubMed Central

    Pino-Yanes, María; Wade, Michael S.; Pérez-Méndez, Lina; Kittles, Rick A.; Wang, Deli; Papaiahgari, Srinivas; Ford, Jean G.; Kumar, Rajesh; Garcia, Joe G. N.

    2012-01-01

    Background Asthma is a common complex condition with clear racial and ethnic differences in both prevalence and severity. Asthma consultation rates, mortality, and severe symptoms are greatly increased in African descent populations of developed countries. African ancestry has been associated with asthma, total serum IgE and lower pulmonary function in African-admixed populations. To replicate previous findings, here we aimed to examine whether African ancestry was associated with asthma susceptibility in African Americans. In addition, we examined for the first time whether African ancestry was associated with asthma exacerbations. Methodology/Principal Findings After filtering for self-reported ancestry and genotype data quality, samples from 1,117 self-reported African-American individuals from New York and Baltimore (394 cases, 481 controls), and Chicago (321 cases followed for asthma exacerbations) were analyzed. Genetic ancestry was estimated based on ancestry informative markers (AIMs) selected for being highly divergent among European and West African populations (95 AIMs for New York and Baltimore, and 66 independent AIMs for Chicago). Among case-control samples, the mean African ancestry was significantly higher in asthmatics than in non-asthmatics (82.0±14.0% vs. 77.8±18.1%, mean difference 4.2% [95% confidence interval (CI):2.0–6.4], p<0.0001). This association remained significant after adjusting for potential confounders (odds ratio: 4.55, 95% CI: 1.69–12.29, p = 0.003). African ancestry failed to show an association with asthma exacerbations (p = 0.965) using a model based on longitudinal data of the number of exacerbations followed over 1.5 years. Conclusions/Significance These data replicate previous findings indicating that African ancestry constitutes a risk factor for asthma and suggest that elevated asthma rates in African Americans can be partially attributed to African genetic ancestry. PMID:22235241

  15. WRKY transcription factor genes in wild rice Oryza nivara.

    PubMed

    Xu, Hengjian; Watanabe, Kenneth A; Zhang, Liyuan; Shen, Qingxi J

    2016-08-01

    The WRKY transcription factor family is one of the largest gene families involved in plant development and stress response. Although many WRKY genes have been studied in cultivated rice (Oryza sativa), the WRKY genes in the wild rice species Oryza nivara, the direct progenitor of O. sativa, have not been studied. O. nivara shows abundant genetic diversity and elite drought and disease resistance features. Herein, a total of 97 O. nivara WRKY (OnWRKY) genes were identified. RNA-sequencing demonstrates that OnWRKY genes were generally expressed at higher levels in the roots of 30-day-old plants. Bioinformatic analyses suggest that most of OnWRKY genes could be induced by salicylic acid, abscisic acid, and drought. Abundant potential MAPK phosphorylation sites in OnWRKYs suggest that activities of most OnWRKYs can be regulated by phosphorylation. Phylogenetic analyses of OnWRKYs support a novel hypothesis that ancient group IIc OnWRKYs were the original ancestors of only some group IIc and group III WRKYs. The analyses also offer strong support that group IIc OnWRKYs containing the HVE sequence in their zinc finger motifs were derived from group Ia WRKYs. This study provides a solid foundation for the study of the evolution and functions of WRKY genes in O. nivara. PMID:27345721

  16. WRKY transcription factor genes in wild rice Oryza nivara

    PubMed Central

    Xu, Hengjian; Watanabe, Kenneth A.; Zhang, Liyuan; Shen, Qingxi J.

    2016-01-01

    The WRKY transcription factor family is one of the largest gene families involved in plant development and stress response. Although many WRKY genes have been studied in cultivated rice (Oryza sativa), the WRKY genes in the wild rice species Oryza nivara, the direct progenitor of O. sativa, have not been studied. O. nivara shows abundant genetic diversity and elite drought and disease resistance features. Herein, a total of 97 O. nivara WRKY (OnWRKY) genes were identified. RNA-sequencing demonstrates that OnWRKY genes were generally expressed at higher levels in the roots of 30-day-old plants. Bioinformatic analyses suggest that most of OnWRKY genes could be induced by salicylic acid, abscisic acid, and drought. Abundant potential MAPK phosphorylation sites in OnWRKYs suggest that activities of most OnWRKYs can be regulated by phosphorylation. Phylogenetic analyses of OnWRKYs support a novel hypothesis that ancient group IIc OnWRKYs were the original ancestors of only some group IIc and group III WRKYs. The analyses also offer strong support that group IIc OnWRKYs containing the HVE sequence in their zinc finger motifs were derived from group Ia WRKYs. This study provides a solid foundation for the study of the evolution and functions of WRKY genes in O. nivara. PMID:27345721

  17. Processes Underpinning Development and Maintenance of Diversity in Rice in West Africa: Evidence from Combining Morphological and Molecular Markers

    PubMed Central

    Maat, Harro; Richards, Paul; Struik, Paul C.

    2014-01-01

    We assessed the interplay of artificial and natural selection in rice adaptation in low-input farming systems in West Africa. Using 20 morphological traits and 176 molecular markers, 182 farmer varieties of rice (Oryza spp.) from 6 West African countries were characterized. Principal component analysis showed that the four botanical groups (Oryza sativa ssp. indica, O. sativa ssp. japonica, O. glaberrima, and interspecific farmer hybrids) exhibited different patterns of morphological diversity. Regarding O. glaberrima, morphological and molecular data were in greater conformity than for the other botanical groups. A clear difference in morphological features was observed between O. glaberrima rices from the Togo hills and those from the Upper Guinea Coast, and among O. glaberrima rices from the Upper Guinea Coast. For the other three groups such clear patterns were not observed. We argue that this is because genetic diversity is shaped by different environmental and socio-cultural selection pressures. For O. glaberrima, recent socio-cultural selection pressures seemed to restrict genetic diversity while this was not observed for the other botanical groups. We also show that O. glaberrima still plays an important role in the selection practices of farmers and resulting variety development pathways. This is particularly apparent in the case of interspecific farmer hybrids where a relationship was found between pericarp colour, panicle attitude and genetic diversity. Farmer varieties are the product of long and complex trajectories of selection governed by local human agency. In effect, rice varieties have emerged that are adapted to West African farming conditions through genotype × environment × society interactions. The diversity farmers maintain in their rice varieties is understood to be part of a risk-spreading strategy that also facilitates successful and often serendipitous variety innovations. We advocate, therefore, that farmers and farmer varieties should

  18. Potential and limitations of Burgundy truffle cultivation.

    PubMed

    Stobbe, Ulrich; Egli, Simon; Tegel, Willy; Peter, Martina; Sproll, Ludger; Büntgen, Ulf

    2013-06-01

    Burgundy truffles (Tuber aestivum syn. Tuber uncinatum) are the highly prized fruit bodies of subterranean fungi always occurring in ectomycorrhizal symbiosis with host plants. Successful cultivation can be achieved through artificial mycorrhization and outplanting of mostly oaks and hazel on suitable terrain. Here, we review ecological requirements, the influence of environmental factors, and the importance of molecular techniques for a successful cultivation of T. aestivum across Europe. The historical background and current knowledge of T. aestivum cultivation are discussed in light of its socioeconomic relevance. PMID:23666478

  19. Tillering and panicle branching genes in rice.

    PubMed

    Liang, Wei-hong; Shang, Fei; Lin, Qun-ting; Lou, Chen; Zhang, Jing

    2014-03-01

    Rice (Oryza sativa L.) is one of the most important staple food crops in the world, and rice tillering and panicle branching are important traits determining grain yield. Since the gene MONOCULM 1 (MOC 1) was first characterized as a key regulator in controlling rice tillering and branching, great progress has been achieved in identifying important genes associated with grain yield, elucidating the genetic basis of yield-related traits. Some of these important genes were shown to be applicable for molecular breeding of high-yielding rice. This review focuses on recent advances, with emphasis on rice tillering and panicle branching genes, and their regulatory networks. PMID:24345551

  20. Mammalian cell cultivation in space

    NASA Astrophysics Data System (ADS)

    Gmünder, Felix K.; Suter, Robert N.; Kiess, M.; Urfer, R.; Nordau, C.-G.; Cogoli, A.

    Equipment used in space for the cultivation of mammalian cells does not meet the usual standard of earth bound bioreactors. Thus, the development of a space worthy bioreactor is mandatory for two reasons: First, to investigate the effect on single cells of the space environment in general and microgravity conditions in particular, and second, to provide researchers on long term missions and the Space Station with cell material. However, expertise for this venture is not at hand. A small and simple device for animal cell culture experiments aboard Spacelab (Dynamic Cell Culture System; DCCS) was developed. It provides 2 cell culture chambers, one is operated as a batch system, the other one as a perfusion system. The cell chambers have a volume of 200 μl. Medium exchange is achieved with an automatic osmotic pump. The system is neither mechanically stirred nor equipped with sensors. Oxygen for cell growth is provided by a gas chamber that is adjacent to the cell chambers. The oxygen gradient produced by the growing cells serves to maintain the oxygen influx by diffusion. Hamster kidney cells growing on microcarriers were used to test the biological performance of the DCCS. On ground tests suggest that this system is feasible.

  1. Iron Biofortification of Myanmar Rice

    PubMed Central

    Aung, May Sann; Masuda, Hiroshi; Kobayashi, Takanori; Nakanishi, Hiromi; Yamakawa, Takashi; Nishizawa, Naoko K.

    2013-01-01

    Iron (Fe) deficiency elevates human mortality rates, especially in developing countries. In Myanmar, the prevalence of Fe-deficient anemia in children and pregnant women are 75 and 71%, respectively. Myanmar people have one of the highest per capita rice consumption rates globally. Consequently, production of Fe-biofortified rice would likely contribute to solving the Fe-deficiency problem in this human population. To produce Fe-biofortified Myanmar rice by transgenic methods, we first analyzed callus induction and regeneration efficiencies in 15 varieties that are presently popular because of their high-yields or high-qualities. Callus formation and regeneration efficiency in each variety was strongly influenced by types of culture media containing a range of 2,4-dichlorophenoxyacetic acid concentrations. The Paw San Yin variety, which has a high-Fe content in polished seeds, performed well in callus induction and regeneration trials. Thus, we transformed this variety using a gene expression cassette that enhanced Fe transport within rice plants through overexpression of the nicotianamine synthase gene HvNAS1, Fe flow to the endosperm through the Fe(II)-nicotianamine transporter gene OsYSL2, and Fe accumulation in endosperm by the Fe storage protein gene SoyferH2. A line with a transgene insertion was successfully obtained. Enhanced expressions of the introduced genes OsYSL2, HvNAS1, and SoyferH2 occurred in immature T2 seeds. The transformants accumulated 3.4-fold higher Fe concentrations, and also 1.3-fold higher zinc concentrations in T2 polished seeds compared to levels in non-transgenic rice. This Fe-biofortified rice has the potential to reduce Fe-deficiency anemia in millions of Myanmar people without changing food habits and without introducing additional costs. PMID:23750162

  2. Low Carbon Rice Farming Practices in the Mekong Delta Yield Significantly Higher Profits and Lower Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Rudek, J.; Van Sanh, N.; Tinh, T. K.; Tin, H. Q.; Thu Ha, T.; Pha, D. N.; Cui, T. Q.; Tin, N. H.; Son, N. N.; Thanh, H. H.; Kien, H. T.; Kritee, K.; Ahuja, R.

    2014-12-01

    The Vietnam Low-Carbon Rice Project (VLCRP) seeks to significantly reduce GHG emissions from rice cultivation, an activity responsible for more than 30% of Vietnam's overall GHG emissions, while improving livelihoods for the rice farmer community by decreasing costs and enhancing yield as well as providing supplemental farmer income through the sale of carbon credits. The Mekong Delta makes up 12% of Vietnam's land area, but produces more than 50% of the country's rice, including more than 90% of the rice for export. Rice cultivation is the main source of income for 80% of farmers in the Mekong Delta. VLCRP was launched in late 2012 in the Mekong Delta in two major rice production provinces, Kien Giang and An Giang. To date, VLCRP has completed 11 crop seasons (in Kien Giang and An Giang combined), training over 400 farmer households in applying VLCRP's package of practices (known as 1 Must - 6 Reductions) and building technical capacity to its key stakeholders and rice farmer community leaders. By adopting the 1 Must- 6 Reductions practices (including reduced seeding density, reduced fertilizer and pesticide application, and alternative wetting and drying water management), rice farmers reduce their input costs while maintaining or improving yields, and decreasing greenhouse gas emissions. The VLCRP package of practices also deliver other environmental and social co-benefits, such as reduced water pollution, improved habitat for fishery resources and reduced health risks for farmers through the reduction of agri-chemicals. VLCRP farmers use significantly less inputs (50% reduction in seed, 30% reduction in fertilizer, 40-50% reduction in water) while improving yields 5-10%, leading to an increase in profit from 10% to as high as 60% per hectare. Preliminary results indicate that the 1 Must- 6 Reductions practices have led to approximately 40-65% reductions in greenhouse gas emissions, equivalent to 4 tons of CO2e/ha/yr in An Giang and 35 tons of CO2e/ha/yr in Kien

  3. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    PubMed

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas. PMID:26974480

  4. Study on allelopathic effects of Rice and Wheat Soil-Like Substrate on several plants

    NASA Astrophysics Data System (ADS)

    Li, Leyuan; Fu, Wenting; He, Wenting; Liu, Hong

    Rice and wheat are the traditional food of Chinese people, and therefore the main crop candidates for bio-regenerative life-support systems. Recycling rice and wheat straw is an important issue concerning the system. In order to decide if the mixed-substrate made of rice and wheat straw is suitable of plant cultivation, Rice and Wheat Soil-Like Substrate was tested in an aqueous extract germination experiment. The effects of different concentrations of aqueous extract on seed vigor, seedling growth and development situations and the physiological and biochemical characteristics of wheat, lettuce and pumpkin were studied, and the presence and degrees of allelopathic effects were analyzed. The test results showed that this type of SLS exerted different degrees of allelopathic effect on wheat and lettuce; this allelopathic effect was related to the concentration of SLS aqueous extract. The most significant phenomenon is that with the increase of aqueous extract concentration, the seed germination, root length and shoot fresh weight of wheat decreased; and every concentration of aqueous extract showed significant inhibition on the root length and root fresh weight of lettuce. However, this type of SLS showed little effect on the growth of pumpkin seedlings. Contents changes of chlorophyll and endogenous hormones in wheat and lettuce seedlings, and the chemical compositions of SLS were measured, and the mechanism of allelopathic effect was preliminarily analyzed.

  5. Stunt or elongate? Two opposite strategies by which rice adapts to floods.

    PubMed

    Nagai, Keisuke; Hattori, Yoko; Ashikari, Motoyuki

    2010-05-01

    Expansion of habitat is important for the perpetuation of species. In particular, plants which are sedentary must evolve specialized functions to adapt itself to new environment. Deepwater rice is cultivated mainly in the lowland areas of South and Southeast Asia that are flooded during the rainy season. The internodes of deepwater rice elongates in response to increasing water level to keep its leaves above the water surface and avoid anoxia. This elongation is stimulated by ethylene-regulated genes, Snorkel1 and Snorkel2. In contrast, when a flash flood occurs at the seedling stage, submergence-tolerant rice, which carries Submergence-1A, remains stunted and survives in water for a few weeks to avoid the energy consumption associated with plant elongation, and restarts its growth using its conserved energy after the water recedes. Interestingly, both Snorkel genes and Submergence-1A encode ethylene-responsive factor-type transcription factor and are connected to gibberellin biosynthesis or signal transduction. However, deepwater and submergence-tolerant rice seem to have opposite flooding response; namely, escape by elongation or remain stunted under water until flood recedes. PMID:20354754

  6. Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice.

    PubMed

    Eguchi, Tetsuya; Ohta, Takeshi; Ishikawa, Tetsuya; Matsunami, Hisaya; Takahashi, Yoshihiko; Kubo, Katashi; Yamaguchi, Noriko; Kihou, Nobuharu; Shinano, Takuro

    2015-09-01

    A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ((137)Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the (137)Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice. PMID:26026983

  7. Rice responses to rising temperatures--challenges, perspectives and future directions.

    PubMed

    Jagadish, S V K; Murty, M V R; Quick, W P

    2015-09-01

    Phenotypic plasticity in overcoming heat stress-induced damage across hot tropical rice-growing regions is predominantly governed by relative humidity. Expression of transpiration cooling, an effective heat-avoiding mechanism, will diminish with the transition from fully flooded paddies to water-saving technologies, such as direct-seeded and aerobic rice cultivation, thus further aggravating stress damage. This change can potentially introduce greater sensitivity to previously unaffected developmental stages such as floral meristem (panicle) initiation and spikelet differentiation, and further intensify vulnerability at the known sensitive gametogenesis and flowering stages. More than the mean temperature rise, increased variability and a more rapid increase in nighttime temperature compared with the daytime maximum present a greater challenge. This review addresses (1) the importance of vapour pressure deficit under fully flooded paddies and increased vulnerability of rice production to heat stress or intermittent occurrence of combined heat and drought stress under emerging water-saving rice technologies; (2) the major disconnect with high night temperature response between field and controlled environments in terms of spikelet sterility; (3) highlights the most important mechanisms that affect key grain quality parameters, such as chalk formation under heat stress; and finally (4), we model and estimate heat stress-induced spikelet sterility taking South Asia as a case study. PMID:25142172

  8. Growth promotion and inhibition of the Amazonian wild rice species Oryza grandiglumis to survive flooding.

    PubMed

    Okishio, Takuma; Sasayama, Daisuke; Hirano, Tatsuya; Akimoto, Masahiro; Itoh, Kazuyuki; Azuma, Tetsushi

    2014-09-01

    In Asian cultivated rice (Oryza sativa), distinct mechanisms to survive flooding are activated in two groups of varieties. Submergence-tolerant rice varieties possessing the SUBMERGENCE1A (SUB1A) gene display reduced growth during flash floods at the seedling stage and resume growth after the flood recedes, whereas deepwater rice varieties possessing the SNORKEL1 (SK1) and SNORKEL2 (SK2) genes display enhanced growth based on internodal elongation during prolonged submergence at the mature stage. In this study, we investigated the occurrence of these growth responses to submergence in the wild rice species Oryza grandiglumis, which is native to the Amazon floodplains. When subjected to gradual submergence, adult plants of O. grandiglumis accessions showed enhanced internodal elongation with rising water level and their growth response closely resembled that of deepwater varieties of O. sativa with high floating capacity. On the other hand, when subjected to complete submergence, seedlings of O. grandiglumis accessions displayed reduced shoot growth and resumed normal growth after desubmergence, similar to the response of submergence-tolerant varieties of O. sativa. Neither SUB1A nor the SK genes were detected in the O. grandiglumis accessions. These results indicate that the O. grandiglumis accessions are capable of adapting successfully to flooding by activating two contrasting mechanisms as the situation demands and that each mechanism of adaptation to flooding is not mediated by SUB1A or the SK genes. PMID:24893854

  9. Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium.

    PubMed

    Moreno-Jiménez, Eduardo; Meharg, Andrew A; Smolders, Erik; Manzano, Rebeca; Becerra, Daniel; Sánchez-Llerena, Javier; Albarrán, Ángel; López-Piñero, Antonio

    2014-07-01

    Previous studies have demonstrated that rice cultivated under flooded conditions has higher concentrations of arsenic (As) but lower cadmium (Cd) compared to rice grown in unsaturated soils. To validate such effects over long terms under Mediterranean conditions a field experiment, conducted over 7 successive years was established in SW Spain. The impact of water management on rice production and grain arsenic (As) and cadmium (Cd) was measured, and As speciation was determined to inform toxicity evaluation. Sprinkler irrigation was compared to traditional flooding. Both irrigation techniques resulted in similar grain yields (~3000 kg grain ha(-1)). Successive sprinkler irrigation over 7 years decreased grain total As to one-sixth its initial concentration in the flooded system (0.55 to 0.09 mg As kg(-1)), while one cycle of sprinkler irrigation also reduced grain total As by one-third (0.20 mg kg(-1)). Grain inorganic As concentration increased up to 2 folds under flooded conditions compared to sprinkler irrigated fields while organic As was also lower in sprinkler system treatments, but to a lesser extent. This suggests that methylation is favored under water logging. However, sprinkler irrigation increased Cd transfer to grain by a factor of 10, reaching 0.05 mg Cd kg(-1) in 7 years. Sprinkler systems in paddy fields seem particularly suited for Mediterranean climates and are able to mitigate against excessive As accumulation, but our evidence shows that an increased Cd load in rice grain may result. PMID:24742557

  10. Direct N2O emissions from rice paddy fields: Summary of available data

    NASA Astrophysics Data System (ADS)

    Akiyama, Hiroko; Yagi, Kazuyuki; Yan, Xiaoyuan

    2005-03-01

    Rice cultivation is an important anthropogenic source of atmospheric nitrous oxide (N2O) and methane. We compiled and analyzed data on N2O emissions from rice fields (113 measurements from 17 sites) reported in peer-reviewed journals. Mean N2O emission ± standard deviation and mean fertilizer-induced emission factor during the rice-cropping season were, respectively, 341 ± 474 g N ha-1 season-1 and 0.22 ± 0.24% for fertilized fields continuously flooded, 993 ± 1075 g N ha-1 season-1 and 0.37 ± 0.35% for fertilized fields with midseason drainage, and 667 ± 885 g N ha-1 season-1 and 0.31 ± 0.31% for all water regimes. The estimated whole-year background emission was 1820 g N ha-1 yr-1. A large uncertainty remains, especially for background emission because of limited data availability. Although midseason drainage generally reduces CH4 and increases N2O emissions, it may be an effective option for mitigating the net global warming potential of rice fields.

  11. Weedy (red) rice: An emerging constraint to global rice production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ongoing increases in the human population necessitate that rice will continue to be an essential aspect of food security for the 21st century. While production must increase in the coming decades to meet demand, such increases will be accompanied by diminished natural resources and rising productio...

  12. Creating rigorous pathways to monetize methane and nitrous oxide emission reductions at small scale rice farms in three states of semi-arid peninsular India

    NASA Astrophysics Data System (ADS)

    Kritee, K.; Tiwari, R.; Nair, D.; Adhya, T. K.; Rudek, J.

    2014-12-01

    As a part of a joint undertaking by Environmental Defense Fund and the Fair Climate Network, we have measured reduction in methane and nitrous oxide emissions due to alternate "low carbon" rice cultivation practices for three ago-ecological zones in India for the past two years. Sampling for nitrous oxide and methane emissions was done on approximately 60-80% of the total number of days in a growing season and was based on modified GRACEnet protocol. In recognition of farmer's economic interest and global food security demands, we also measured the effect of rice cultivation practices on farm economics and yields. Our data from three agro-ecological zones for 2012-2014 suggest that, for semi-arid peninsular India, low-carbon rice cultivation practices offer large range of emission reduction potential (0.5-5 metric tons CO2e/acre/year). The regions with sandy soils (Alfisols) had high rates of nitrous oxide emissions even under baseline "flooded" rice cultivation regimes and, thus, the Tier 1 IPCC emissions factors grossly underestimate both the amount of nitrous oxide emission from conventional rice cultivation practices, and the extent to which it can be reduced through better fertilizer management. Also, the IPCC factors overestimate the methane emission reduction possible due to water management for rice paddies. Therefore, it is crucial to customize N and water management to each region such that yields and net GHG emission reduction are maximized. These practices also have the potential to decrease water use by 10-30% and improve long term soil health by optimizing organic matter and increasing water-holding capacity. In addition, through GPS based demarcation of farmer plots, recording baseline practices through extensive surveys, documenting the parameters required to aggregate and prove implementation of low carbon rice farming practices, and to model the GHG emission reduction over large scales, we have put forward a path for better monetization of GHG

  13. Insights into molecular mechanism of blast resistance in weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy rice is a serious pest in direct-seeded rice fields in the U.S. and worldwide. Under suitable conditions, weedy rice can reduce crop yields up to 70%. However, weedy rice may carry novel disease resistance genes. Rice blast disease caused by the fungus Magnaporthe oryzae is a major disease wo...

  14. Translational genomics-rice research in agriculture research service

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the US accounts for only approximately 1.6 % of the total world rice production, it provides about 15% of the rice in world trade, and its rice is known for its high quality. Rice is a model for genomic study of monocots and thus, numerous broad-spectrum research activities involving rice ...

  15. Understanding traditional African healing

    PubMed Central

    MOKGOBI, M.G.

    2015-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists. PMID:26594664

  16. Modeling the impacts of alternative fertilization methods on nitrogen loading in rice production in Shanghai.

    PubMed

    Zhao, Zheng; Sha, Zhimin; Liu, Yibo; Wu, Shuhang; Zhang, Hanlin; Li, Changsheng; Zhao, Qi; Cao, Linkui

    2016-10-01

    Nitrogen (N) loss from paddy fields is an important source of agricultural non-point source pollution that leads to eutrophication of water bodies and degradation of water quality. The impacts of alternative N fertilizer management practices on N loading (N loss through runoff and leaching) from paddy fields in Shanghai were assessed using a process-based biogeochemical model, DNDC. The results indicated that the current fertilization rate in paddy fields of Shanghai (300kgN/ha) exceeds the actual rice demand and has led to substantial N loading of 1142±276kg. The combined application of urea at 150kgN/ha and organic manure at 100kgN/ha was identified as the best fertilization method for rice cultivation in Shanghai; this application maintained optimal rice yields and significantly reduced N loading to 714±151kg in comparison with the current fertilization rate. A sensitivity test was conducted with various input parameters, and the results indicated that fertilization, precipitation and soil properties were the most sensitive factors that regulate N loss from paddy fields. The variability of soil properties, especially SOC led to high uncertainties in the simulated results. Therefore, the local climate conditions and soil properties should be taken into account in the identification of the best management practice (BMP) for rice cultivation, given the high spatially heterogeneous N loading values across all towns used in the simulation. The DNDC model is an effective approach for simulating and predicting N loading in paddy fields under alternative agricultural management practices. PMID:27317135

  17. Pensions for 'cultivators of science'.

    PubMed

    Crosland, Maurice

    2010-10-01

    The occasional (and belated) concern of the British Government with science in the nineteenth century is a matter of potential interest to historians of science, yet many previous studies have tended to range over a variety of different aspects of the question. There have been too many vague allusions to financial support as 'money for science' in general. It is time that particular parts of the problem were unpacked. For example, the award of money (from the 1820s) to pay a few people of independent means for apparatus was quite distinct from the provision (from the 1830s) of an occasional pension. Even then, to speak of 'pensions' uncovers unfortunate ambiguities. For too long science in Britain was regarded as no more than a private hobby for the well-to-do. As late as 1856 an official government statement seemed to make this attitude official. The English attitude to pensions differed remarkably from the French, who established a precedent in the reward of savants, sometimes quoted enviously by British men of science. In 1837 Robert Peel virtually admitted that, in awarding pensions to 'cultivators of science', he was following the French practice. It may also be useful to emphasise the contrast between the English (often led by Cambridge professors) and the Scots, mostly from Edinburgh, mainly represented here by Whewell and Brewster, respectively. Babbage had a different role in this story from that usually told. A large part in supporting men of science of modest means could have been played by the British Association for the Advancement of Science but it consistently refused to do so, although it supported an elite among its own members. PMID:21466131

  18. Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells.

    PubMed

    Friedman, Mendel

    2013-11-13

    Rice plants produce bioactive rice brans and hulls that have been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, this paper also presents brief summaries on the preparation of health-promoting foods including bread, corn flakes, frankfurters, ice cream, noodles, pasta, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical, and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional foods as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described health-promoting potential of the rice-derived brans, oils, and hulls in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies. PMID:24175575

  19. African horse sickness.

    PubMed

    Zientara, S; Weyer, C T; Lecollinet, S

    2015-08-01

    African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis. PMID:26601437

  20. Agriculture Education. Soybeans and Rice.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary students enrolled in one or two semester-long courses in agricultural education. The guide presents units of study in the following areas: (1) soybeans, (2) rice, and (3) orientation. Each of the 17 units of instruction follows a typical format: terminal objective, specific…