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Sample records for allotetraploid rice species

  1. Conditions in home and transplant soils have differential effects on the performance of diploid and allotetraploid anthericum species.

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    Lucie Černá

    Full Text Available Due to increased levels of heterozygosity, polyploids are expected to have a greater ability to adapt to different environments than their diploid ancestors. While this theoretical pattern has been suggested repeatedly, studies comparing adaptability to changing conditions in diploids and polyploids are rare. The aim of the study was to determine the importance of environmental conditions of origin as well as target conditions on performance of two Anthericum species, allotetraploid A. liliago and diploid A. ramosum and to explore whether the two species differ in the ability to adapt to these environmental conditions. Specifically, we performed a common garden experiment using soil from 6 localities within the species' natural range, and we simulated the forest and open environments in which they might occur. We compared the performance of diploid A. ramosum and allotetraploid A. liliago originating from different locations in the different soils. The performance of the two species was not affected by simulated shading but differed strongly between the different target soils. Growth of the tetraploids was not affected by the origin of the plants. In contrast, diploids from the most nutrient poor soil performed best in the richest soil, indicating that diploids from deprived environments have an increased ability to acquire nutrients when available. They are thus able to profit from transfer to novel nutrient rich environments. Therefore, the results of the study did not support the general expectation that the polyploids should have a greater ability than the diploids to adapt to a wide range of conditions. In contrast, the results are in line with the observation that diploids occupy a wider range of environments than the allotetraploids in our system.

  2. Deciphering the complex leaf transcriptome of the allotetraploid species Nicotiana tabacum: a phylogenomic perspective

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    Bombarely Aureliano

    2012-08-01

    Full Text Available Abstract Background Polyploidization is an important mechanism in plant evolution. By analyzing the leaf transcriptomes taken from the allotetraploid Nicotiana tabacum (tobacco and parental genome donors, N. sylvesteris (S-Genome and N. tomentosiformis (T-Genome, a phylogenomic approach was taken to map the fate of homeologous gene pairs in this plant. Results A comparison between the genes present in the leaf transcriptomes of N. tabacum and modern day representatives of its progenitor species demonstrated that only 33% of assembled transcripts could be distinguished based on their sequences. A large majority of the genes (83.6% of the non parent distinguishable and 87.2% of the phylogenetic topology analyzed clusters expressed above background level (more than 5 reads showed similar overall expression levels. Homeologous sequences could be identified for 968 gene clusters, and 90% (6% of all genes of the set maintained expression of only one of the tobacco homeologs. When both homeologs were expressed, only 15% (0.5% of the total showed evidence of differential expression, providing limited evidence of subfunctionalization. Comparing the rate of synonymous nucleotide substitution (Ks and non-synonymous nucleotide substitution (Kn provided limited evidence for positive selection during the evolution of tobacco since the polyploidization event took place. Conclusions Polyploidization is a powerful mechanism for plant speciation that can occur during one generation; however millions of generations may be necessary for duplicate genes to acquire a new function. Analysis of the tobacco leaf transcriptome reveals that polyploidization, even in a young tetraploid such as tobacco, can lead to complex changes in gene expression. Gene loss and gene silencing, or subfunctionalization may explain why both homeologs are not expressed by the associated genes. With Whole Genome Duplication (WGD events, polyploid genomes usually maintain a high percentage of

  3. Transcriptome Assembly and Comparison of an Allotetraploid Weed Species, Annual Bluegrass, with its Two Diploid Progenitor Species, Poa supina Schrad and Poa infirma Kunth

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    Shu Chen

    2016-03-01

    Full Text Available Annual bluegrass ( L. is one of the most widespread weed species in this world. As a young allotetraploid, has occupied diverse environments from Antarctic area to subtropical regions. To unveil the evolutionary mystery behind ’s wide distribution, extensive adaptability and phenotypic plasticity needs collaboration from multiple research scopes from ecology and plant physiology to population genetics and molecular biology. However, the lack of omic data and reference has greatly hampered the study. This is the first comprehensive transcriptome study on species. Total RNA was extracted from and its two proposed diploid parents, Schrad and Kunth, and sequenced in Illumina Hiseq2000. Optimized, nonredundant transcriptome references were generated for each species using four de novo assemblers (Trinity, Velvet, SOAPdenovo, and CLC Genomics Workbench and a redundancy-reducing pipeline (CD-HIT-EST and EvidentialGene tr2aacds. Using the constructed transcriptomes together with sequencing reads, we found high similarity in nucleotide sequences and homeologous polymorphisms between and the two proposed parents. Comparison of chloroplast and mitochondrion genes further confirmed as the maternal parent. Less nucleotide percentage differences were observed between and homeologs than between and homeologs, indicating a higher nucleotide substitution rates in homeologs than in homeologs. Gene ontology (GO enrichment analysis suggested the more compatible cytoplasmic environment and cellular apparatus for homeologs as the major cause for this phenomenon.

  4. Grain Unloading Of Arsenic Species In Rice

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    Rice (Oryza sativa) is the staple food for over half the world's population yet may represent a significant dietary source of inorganic arsenic (As), a nonthreshold, class 1 human carcinogen. Rice grain As is dominated by the inorganic species, and the organic species dim...

  5. Grain Unloading of Arsenic Species in Rice

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    Carey, Anne-Marie; Scheckel, Kirk G.; Lombi, Enzo; Newville, Matt; Choi, Yongseong; Norton, Gareth J.; Charnock, John M.; Feldmann, Joerg; Price, Adam H.; Meharg, Andrew A. (EPA); (U. South Australia); (Manchester); (Aberdeen); (UC)

    2010-01-11

    Rice (Oryza sativa) is the staple food for over half the world's population yet may represent a significant dietary source of inorganic arsenic (As), a nonthreshold, class 1 human carcinogen. Rice grain As is dominated by the inorganic species, and the organic species dimethylarsinic acid (DMA). To investigate how As species are unloaded into grain rice, panicles were excised during grain filling and hydroponically pulsed with arsenite, arsenate, glutathione-complexed As, or DMA. Total As concentrations in flag leaf, grain, and husk, were quantified by inductively coupled plasma mass spectroscopy and As speciation in the fresh grain was determined by x-ray absorption near-edge spectroscopy. The roles of phloem and xylem transport were investigated by applying a {+-} stem-girdling treatment to a second set of panicles, limiting phloem transport to the grain in panicles pulsed with arsenite or DMA. The results demonstrate that DMA is translocated to the rice grain with over an order magnitude greater efficiency than inorganic species and is more mobile than arsenite in both the phloem and the xylem. Phloem transport accounted for 90% of arsenite, and 55% of DMA, transport to the grain. Synchrotron x-ray fluorescence mapping and fluorescence microtomography revealed marked differences in the pattern of As unloading into the grain between DMA and arsenite-challenged grain. Arsenite was retained in the ovular vascular trace and DMA dispersed throughout the external grain parts and into the endosperm. This study also demonstrates that DMA speciation is altered in planta, potentially through complexation with thiols.

  6. A New Synthetic Allotetraploid (A1A1G2G2) between Gossypium herbaceum and G. australe: Bridging for Simultaneously Transferring Favorable Genes from These Two Diploid Species into Upland Cotton

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    Chen, Yu; Wang, Yingying; Chen, Jinjin; Zhang, Tianzhen; Zhou, Baoliang

    2015-01-01

    Gossypium herbaceum, a cultivated diploid cotton species (2n = 2x = 26, A1A1), has favorable traits such as excellent drought tolerance and resistance to sucking insects and leaf curl virus. G. australe, a wild diploid cotton species (2n = 2x = 26, G2G2), possesses numerous economically valuable characteristics such as delayed pigment gland morphogenesis (which is conducive to the production of seeds with very low levels of gossypol as a potential food source for humans and animals) and resistance to insects, wilt diseases and abiotic stress. Creating synthetic allotetraploid cotton from these two species would lay the foundation for simultaneously transferring favorable genes into cultivated tetraploid cotton. Here, we crossed G. herbaceum (as the maternal parent) with G. australe to produce an F1 interspecific hybrid and doubled its chromosome complement with colchicine, successfully generating a synthetic tetraploid. The obtained tetraploid was confirmed by morphology, cytology and molecular markers and then self-pollinated. The S1 seedlings derived from this tetraploid gradually became flavescent after emergence of the fifth true leaf, but they were rescued by grafting and produced S2 seeds. The rescued S1 plants were partially fertile due to the existence of univalents at Metaphase I of meiosis, leading to the formation of unbalanced, nonviable gametes lacking complete sets of chromosomes. The S2 plants grew well and no flavescence was observed, implying that interspecific incompatibility, to some extent, had been alleviated in the S2 generation. The synthetic allotetraploid will be quite useful for polyploidy evolutionary studies and as a bridge for transferring favorable genes from these two diploid species into Upland cotton through hybridization. PMID:25879660

  7. Genetic Diversity of Wild Rice Species in Yunnan Province of China

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    Zai-quan CHENG; Fu-you YING; Ding-qing LI; Teng-qiong YU; Jian FU; Hui-jun YAN; Qiao-fang ZHONG; Dun-yu ZHANG; Wei-jiao LI; Xing-qi HUANG

    2012-01-01

    Yunnan Province of China is one of the important centers for origin and evolution of cultivated rice worldwide. Wild rice is the ancestor of the cultivated rice. Many elite traits of wild rice have widened the genetic basis in cultivated rice. However, many populations of wild rice species have disappeared in the past few years. Therefore, the current status of wild rice resources should be updated and the genetic diversity of wild rice species should be examined for further germplasm preserv...

  8. Mycoflora and aflatoxigenic species in derivatives of milled rice

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    LIMA Carlos A. P.

    2000-01-01

    Full Text Available Thirty samples of rough rice stored for 6, 12 and 24 months in government authorized warehouses of the state of Rio Grande do Sul, Brazil, were simultaneously collected. After milling of the product, 90 samples (30 of polished rice, 30 of rice bran and 30 of rice hull were evaluated for their mycoflora, aflatoxigenic species and aflatoxin contamination. The following fungi, listed in decreasing order of frequency, were isolated on Potato-Dextrose Agar: Aspergillus spp., Nigrospora spp., Penicillium spp.; Fusarium spp.; Mucor spp.; Cladosporium spp.; Trichosporon spp. and non-sporulated fungi. The degree of fungal contamination (colony forming units per gram of product was lowest in polished rice, increasing progressively in samples of rice bran and rice hull. Among the Aspergillus species, A. flavus and A. candidus were isolated most frequently. Of the A. flavus isolates, 52.6% strains were found to be toxigenic and produced only Group B aflatoxins. Analysis of the 90 samples did not reveal the presence of aflatoxins in the rice derivatives.

  9. The genome structure of Arachis hypogaea (Linnaeus, 1753 and an induced Arachis allotetraploid revealed by molecular cytogenetics

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    Eliza F. de M. B. do Nascimento

    2018-03-01

    Full Text Available Peanut, Arachis hypogaea (Linnaeus, 1753 is an allotetraploid cultivated plant with two subgenomes derived from the hybridization between two diploid wild species, A. duranensis (Krapovickas & W. C. Gregory, 1994 and A. ipaensis (Krapovickas & W. C. Gregory, 1994, followed by spontaneous chromosomal duplication. To understand genome changes following polyploidy, the chromosomes of A. hypogaea, IpaDur1, an induced allotetraploid (A. ipaensis × A. duranensis4x and the diploid progenitor species were cytogenetically compared. The karyotypes of the allotetraploids share the number and general morphology of chromosomes; DAPI+ bands pattern and number of 5S rDNA loci. However, one 5S rDNA locus presents a heteromorphic FISH signal in both allotetraploids, relative to corresponding progenitor. Whilst for A. hypogaea the number of 45S rDNA loci was equivalent to the sum of those present in the diploid species, in IpaDur1, two loci have not been detected. Overall distribution of repetitive DNA sequences was similar in both allotetraploids, although A. hypogaea had additional CMA3+ bands and few slight differences in the LTR-retrotransposons distribution compared to IpaDur1. GISH showed that the chromosomes of both allotetraploids had preferential hybridization to their corresponding diploid genomes. Nevertheless, at least one pair of IpaDur1 chromosomes had a clear mosaic hybridization pattern indicating recombination between the subgenomes, clear evidence that the genome of IpaDur1 shows some instability comparing to the genome of A. hypogaea that shows no mosaic of subgenomes, although both allotetraploids derive from the same progenitor species. For some reasons, the chromosome structure of A. hypogaea is inherently more stable, or, it has been at least, partially stabilized through genetic changes and selection.

  10. Arsenic species in raw and cooked rice: Implications for human health in rural Bengal

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    Halder, Dipti, E-mail: dipti@kth.se [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden); Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Biswas, Ashis [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden); Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Šlejkovec, Zdenka [Environmental Sciences Department, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Chatterjee, Debashis [Department of Chemistry, University of Kalyani, Kalyani, 741 235, West Bengal (India); Nriagu, Jerome [Department of Environmental Health Sciences, School of Public Health, University of Michigan, 109 Observatory Street, Ann Arbor, MI 48109-2029 (United States); Jacks, Gunnar; Bhattacharya, Prosun [KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm (Sweden)

    2014-11-01

    This study compares the concentrations of total and different species of arsenic (As) in 29 pairs of raw and cooked rice samples collected from households in an area of West Bengal affected by endemic arsenicism. The aim is to investigate the effects of indigenous cooking practice of the rural villagers on As accumulation and speciation in cooked rice. It is found that inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). Cooking of rice with water low in As (< 10 μg L{sup −1}) significantly decreases the total and inorganic As content in cooked rice compared to raw rice. Arsenic concentration is mainly decreased during boiling of rice grains with excess water. Washing of rice grains with low As water has negligible effect on grain As concentration. The study suggests that rice cooking with low As water by the villagers is a beneficial risk reduction strategy. Despite reductions in As content in cooked rice because of cooking with low As water, the consumption of cooked rice represents a significant health threat (in terms of chronic As toxicity) to the study population. - Highlights: • Pairs of raw and cooked rice samples are collected from households. • Total and different species of As in raw and cooked rice samples are compared. • Cooking with As safe water reduces total and inorganic As contents in cooked rice. • Inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). • Risks of As exposure from cooked rice consumption exceed the safety standards.

  11. Arsenic species in raw and cooked rice: Implications for human health in rural Bengal

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    Halder, Dipti; Biswas, Ashis; Šlejkovec, Zdenka; Chatterjee, Debashis; Nriagu, Jerome; Jacks, Gunnar; Bhattacharya, Prosun

    2014-01-01

    This study compares the concentrations of total and different species of arsenic (As) in 29 pairs of raw and cooked rice samples collected from households in an area of West Bengal affected by endemic arsenicism. The aim is to investigate the effects of indigenous cooking practice of the rural villagers on As accumulation and speciation in cooked rice. It is found that inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). Cooking of rice with water low in As (< 10 μg L −1 ) significantly decreases the total and inorganic As content in cooked rice compared to raw rice. Arsenic concentration is mainly decreased during boiling of rice grains with excess water. Washing of rice grains with low As water has negligible effect on grain As concentration. The study suggests that rice cooking with low As water by the villagers is a beneficial risk reduction strategy. Despite reductions in As content in cooked rice because of cooking with low As water, the consumption of cooked rice represents a significant health threat (in terms of chronic As toxicity) to the study population. - Highlights: • Pairs of raw and cooked rice samples are collected from households. • Total and different species of As in raw and cooked rice samples are compared. • Cooking with As safe water reduces total and inorganic As contents in cooked rice. • Inorganic As is the predominant species in both raw (93.8%) and cooked rice (88.1%). • Risks of As exposure from cooked rice consumption exceed the safety standards

  12. Karyotype stability and unbiased fractionation in the paleo-allotetraploid Cucurbita genomes

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    Sun, Honghe; Wu, Shan; Zhang, Guoyu; Jiao, Chen; Guo, Shaogui; Ren, Yi; Zhang, Jie; Zhang, Haiying; Gong, Guoyi; Jia, Zhangcai; Zhang, Fan; Tian, Jiaxing; Lucas, William; Doyle, Jeff; Li, Haizhen

    2017-01-01

    The Cucurbita genus contains several economically important species in the Cucurbitaceae family. Interspecific hybrids between C. maxima and C. moschata are widely used as rootstocks for other cucurbit crops. We report high-quality genome sequences of C. maxima and C. moschata and provide evidence supporting an allotetraploidization event in Cucurbita. We are able to partition the genome into two homoeologous subgenomes based on different genetic distances to melon, cucumber and watermelon in...

  13. Recreating Stable Brachypodium hybridum Allotetraploids by Uniting the Divergent Genomes of B. distachyon and B. stacei

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    Dinh Thi, Vinh Ha; Coriton, Olivier; Le Clainche, Isabelle; Arnaud, Dominique; Gordon, Sean P.; Linc, Gabriella; Catalan, Pilar; Hasterok, Robert; Vogel, John P.; Jahier, Joseph; Chalhoub, Boulos

    2016-01-01

    Brachypodium hybridum (2n = 30) is a natural allopolyploid with highly divergent sub-genomes derived from two extant diploid species, B. distachyon (2n = 10) and B. stacei (2n = 20) that differ in chromosome evolution and number. We created synthetic B. hybridum allotetraploids by hybridizing various lines of B. distachyon and B. stacei. The initial amphihaploid F1 interspecific hybrids were obtained at low frequencies when B. distachyon was used as the maternal parent (0.15% or 0.245% depending on the line used) and were sterile. No hybrids were obtained from reciprocal crosses or when autotetraploids of the parental species were crossed. Colchicine treatment was used to double the genome of the F1 amphihaploid lines leading to allotetraploids. The genome-doubled F1 plants produced a few S1 (first selfed generation) seeds after self-pollination. S1 plants from one parental combination (Bd3-1×Bsta5) were fertile and gave rise to further generations whereas those of another parental combination (Bd21×ABR114) were sterile, illustrating the importance of the parental lineages crossed. The synthetic allotetraploids were stable and resembled the natural B. hybridum at the phenotypic, cytogenetic and genomic levels. The successful creation of synthetic B. hybridum offers the possibility to study changes in genome structure and regulation at the earliest stages of allopolyploid formation in comparison with the parental species and natural B. hybridum. PMID:27936041

  14. Speciation of arsenic in rice and estimation of daily intake of different arsenic species by Brazilians through rice consumption.

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    Batista, Bruno L; Souza, Juliana M O; De Souza, Samuel S; Barbosa, Fernando

    2011-07-15

    Rice is an important source of essential elements. However, rice may also contain toxic elements such as arsenic. Therefore, in the present study, the concentration of total arsenic and five main chemical species of arsenic (As(3+), As(5+), DMA, MMA and AsB) were evaluated in 44 different rice samples (white, parboiled white, brown, parboiled brown, parboiled organic and organic white) from different Brazilian regions using high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The mean level of total arsenic was 222.8 ng g(-1) and the daily intake of inorganic arsenic (the most toxic form) from rice consumption was estimated as 10% of the Provisional Tolerable Daily Intake (PTDI) with a daily ingestion of 88 g of rice. Inorganic arsenic (As(3+), As(5+)) and dimethylarsinic acid (DMA) are the predominant forms in all samples. The percentages of species were 38.7; 39.7; 3.7 and 17.8% for DMA, As(3+), MMA and As(5+), respectively. Moreover, rice samples harvested in the state of Rio Grande do Sul presented more fractions of inorganic arsenic than rice in Minas Gerais or Goiás, which could lead to different risks of arsenic exposure. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Proteomic analysis of seed storage proteins in wild rice species of the Oryza genus.

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    Jiang, Chunmiao; Cheng, Zaiquan; Zhang, Cheng; Yu, Tengqiong; Zhong, Qiaofang; Shen, J Qingxi; Huang, Xingqi

    2014-01-01

    The total protein contents of rice seeds are significantly higher in the three wild rice species (Oryza rufipogon Grill., Oryza officinalis Wall. and Oryza meyeriana Baill.) than in the cultivated rice (Oryza sativa L.). However, there is still no report regarding a systematic proteomic analysis of seed proteins in the wild rice species. Also, the relationship between the contents of seed total proteins and rice nutritional quality has not been thoroughly investigated. The total seed protein contents, especially the glutelin contents, of the three wild rice species were higher than those of the two cultivated rice materials. Based on the protein banding patterns of SDS-PAGE, O. rufipogon was similar to the two cultivated rice materials, followed by O. officinalis, while O. meyeriana exhibited notable differences. Interestingly, O. meyeriana had high contents of glutelin and low contents of prolamine, and lacked 26 kDa globulin band and appeared a new 28 kDa protein band. However, for O. officinali a 16 kDa protein band was absent and a row of unique 32 kDa proteins appeared. In addition, we found that 13 kDa prolamine band disappeared while special 14 kDa and 12 kDa protein bands were present in O. officinalis. Two-dimensional gel electrophoresis (2-DE) analysis revealed remarkable differences in protein profiles of the wild rice species and the two cultivated rice materials. Also, the numbers of detected protein spots of the three wild rice species were significantly higher than those of two cultivated rice. A total of 35 differential protein spots were found for glutelin acidic subunits, glutelin precursors and glutelin basic subunits in wild rice species. Among those, 18 protein spots were specific and 17 major spots were elevated. Six differential protein spots for glutelin acidic subunits were identified, including a glutelin type-A 2 precursor and five hypothetical proteins. This was the first report on proteomic analysis of the three wild rice species

  16. Molecular and cytogenetic evidence for an allotetraploid origin of Chenopodium quinoa and C. berlandieri (Amaranthaceae).

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    Kolano, Bozena; McCann, Jamie; Orzechowska, Maja; Siwinska, Dorota; Temsch, Eva; Weiss-Schneeweiss, Hanna

    2016-07-01

    Most of the cultivated chenopods are polyploids, but their origin and evolutionary history are still poorly understood. Phylogenetic analyses of DNA sequences of four plastid regions, nrITS and nuclear 5S rDNA spacer region (NTS) of two tetraploid chenopods (2n=4x=36), Andean C. quinoa and North American C. berlandieri, and their diploid relatives allowed inferences of their origin. The phylogenetic analyses confirmed allotetraploid origin of both tetraploids involving diploids of two different genomic groups (genomes A and B) and suggested that these two might share very similar parentage. The hypotheses on the origin of the two allopolyploid species were further tested using genomic in situ hybridization (GISH). Several diploid Chenopodium species belonging to the two lineages, genome A and B, suggested by phylogenetic analyses, were tested as putative parental taxa. GISH differentiated two sets of parental chromosomes in both tetraploids and further corroborated their allotetraploid origin. Putative diploid parental taxa have been suggested by GISH for C. quinoa and C. berlandieri. Genome sizes of the analyzed allotetraploids fit nearly perfectly the expected additive values of the putative parental taxa. Directional and uniparental loss of rDNA loci of the maternal A-subgenome was revealed for both C. berlandieri and C. quinoa. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Physiological and molecular characterization of Si uptake in wild rice species.

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    Mitani-Ueno, Namiki; Ogai, Hisao; Yamaji, Naoki; Ma, Jian Feng

    2014-07-01

    Cultivated rice (Oryza sativa) accumulates high concentration of silicon (Si), which is required for its high and sustainable production. High Si accumulation in cultivated rice is achieved by a high expression of both influx (Lsi1) and efflux (Lsi2) Si transporters in roots. Herein, we physiologically investigated Si uptake, isolated and functionally characterized Si transporters in six wild rice species with different genome types. Si uptake by the roots was lower in Oryza rufipogon, Oryza barthii (AA genome), Oryza australiensis (EE genome) and Oryza punctata (BB genome), but similar in Oryza glumaepatula and Oryza meridionalis (AA genome) compared with the cultivated rice (cv. Nipponbare). However, all wild rice species and the cultivated rice showed similar concentration of Si in the shoots when grown in a field. All species with AA genome showed the same amino acid sequence of both Lsi1 and Lsi2 as O. sativa, whereas species with EE and BB genome showed several nucleotide differences in both Lsi1 and Lsi2. However, proteins encoded by these genes also showed transport activity for Si in Xenopus oocyte. The mRNA expression of Lsi1 in all wild rice species was lower than that in the cultivated rice, whereas the expression of Lsi2 was lower in O. rufipogon and O. barthii but similar in other species. Similar cellular localization of Lsi1 and Lsi2 was observed in all wild rice as the cultivated rice. These results indicate that superior Si uptake, the important trait for rice growth, is basically conserved in wild and cultivated rice species. © 2013 Scandinavian Plant Physiology Society.

  18. Speciation of Six-Arsenic Species of Rice in Korea by HPLC/ICPMS

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    Kim J.Y.

    2013-04-01

    Full Text Available Determination of arsenic (As speciation in rice is necessary because inorganic As species are more toxic than organic As. Arsenic levels of rice in Korea were determined by microwave extraction and High Performance Liquid Chromatography coupled with Inductively Coupled Plasma-Mass Spectrometry. The extraction method showed a high recovery and low Limit of Detection (LOD and Limit of Quantitation (LOQ. Most of the As species in rice were noticed to be inorganic [Arsenite (AsIII, Dimethylarsinic acid (DMA]. The percentage of inorganic As/total As is 69.01 % (36.40-87.86 %. Arsenite and DMA were the major compounds in rice in Korea when compare to U.S. rice. The order and percentage of As species showed were AsIII (56-70 %>DMA (23-38 %>AsV (5 %>MMA(1 %.

  19. Mosquitoes of the rice agroecosystem of Malaysia: species composition and their abundance in relation to rice farming

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    Abu Hassan Ahmad; Che Salmah Md Rawi

    2002-01-01

    Mosquito abundance in relation to rice farming was studied in the Muda and the Kerian Irrigation Schemes. Mosquito larvae were collected using dippers for several growing seasons. Adult mosquitoes were collected by using human bait and cow bait and net trap at nights. Culex, Mansonia and Anopheles were the three genera of mosquito found in the rice agroecosystem. Four species of Mansonia were found biting on human bait. Culex mosquitoes were caught biting on human and cow baits. Culex tritaeniorhynchus, C pseudovishnui, C vishnui, C gelidus and C bitaeniorhynchus were the most common Culex mosquitoes found. Anoheles sinensis and A. peditaeniatus were the most dominant panopheline mosquitoes. High abundance of larvae and adult mosquitoes were observed during ploughing, planting, and tillering stages of rice farming. (Author)

  20. A walk on the wild side: Oryza species as source for rice abiotic stress tolerance.

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    Menguer, Paloma Koprovski; Sperotto, Raul Antonio; Ricachenevsky, Felipe Klein

    2017-01-01

    Oryza sativa, the common cultivated rice, is one of the most important crops for human consumption, but production is increasingly threatened by abiotic stresses. Although many efforts have resulted in breeding rice cultivars that are relatively tolerant to their local environments, climate changes and population increase are expected to soon call for new, fast generation of stress tolerant rice germplasm, and current within-species rice diversity might not be enough to overcome such needs. The Oryza genus contains other 23 wild species, with only Oryza glaberrima being also domesticated. Rice domestication was performed with a narrow genetic diversity, and the other Oryza species are a virtually untapped genetic resource for rice stress tolerance improvement. Here we review the origin of domesticated Oryza sativa from wild progenitors, the ecological and genomic diversity of the Oryza genus, and the stress tolerance variation observed for wild Oryza species, including the genetic basis underlying the tolerance mechanisms found. The summary provided here is important to indicate how we should move forward to unlock the full potential of these germplasms for rice improvement.

  1. Higher taxa as surrogates of species richness of spiders in insect-resistant transgenic rice

    Institute of Scientific and Technical Information of China (English)

    Sheng Lin; Min-Sheng You; Liette Vasseur; Guang Yang; Feng-Jing Liu; Feng Guo

    2012-01-01

    Biodiversity assessments can often be time- and resource-consuming.Several alternative approaches have been proposed to reduce sampling efforts,including indicator taxa and surrogates.In this study,we examine the reliability of higher taxon surrogates to predict species richness in two experimental rice fields of Fujian Province,southeastern China during 2005 and 2009.Spider samples in transgenic and nontransgenic plots were collected using a suction sampler.Both the genus and family surrogates had significant and positive linear relationships with species richness in the transgenic and nontransgenic rice fields.The rice varieties did not significantly influence the linear relationships.Our findings suggest that higher-taxon surrogacy could be a useful alternative to complete species inventory for risk assessments of transgenic rice.

  2. Ultrastructural morphologic description of the wild rice species Oryza latifolia (Poaceae in Costa Rica

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    Ethel Sánchez

    2003-06-01

    Full Text Available The wild rice species Oryza latifolia is endemic to Tropical America, allotetraploid and has a CCDD genome type. It belongs to the officinalis group of the genus Oryza. This species is widely distributed through-out the lowlands of Costa Rica and it is found on different life zones, having great morphologic diversity. The purpose of this research is to perform a morphologic description of O. latifolia samples of three Costa Rican localities (Carara, Liberia and Cañas and to see if the phenotypic diversity of the species is reflected at the ultra-structure level. Structures such as the leaf blade, ligule, auricles and spikelet were analyzed. Leaf blade morphology of the specimens from the three localities is characterized by the presence of diamond-shaped stomata with papillae, zipper-like rows of silica cells; a variety of evenly distributed epicuticular wax papillae and bulky prickle trichomes. The central vein of the leaf blade from the Cañas populations is glabrous, while those from Carara and Liberia have abundant papillae. There are also differences among the borders of the leaf blade between these locations. Cañas and Liberia present alternating large and small prickle trichomes ca. 81 and 150 µm, while Carara exhibits even sized prickle trichomes of ca. 93 µm. Auricles from Cañas are rectangular and present long trichomes along the surface ca. 1.5 mm, while those of Liberia and Carara wrap the culm and exhibit trichomes only in the borders. The ligule from the plants of Carara has an acute distal tip, while that of Cañas and Liberia is blunt. The Liberia spikelet has large lignified spines while Cañas and Carara show flexible trichomes.La especie silvestre Oryza latifolia es endémica de América, tetraploide y de genoma CCDD. Pertenece a las especies del género Oryza del grupo officinalis. Presenta una amplia distribución en las tierras bajas de Costa Rica y se le encuentra en varias zonas de vida, mostrando una gran diversidad

  3. Focal species candidates for pesticide risk assessment in European rice fields: A review.

    Science.gov (United States)

    Vallon, Martin; Dietzen, Christian; Laucht, Silke; Ludwigs, Jan-Dieter

    2018-04-25

    An assessment of potential risks of pesticides on wildlife is required during the process of product registration within Europe because of the importance of agricultural landscapes as wildlife habitats. Despite their peculiarity and their specific role as artificial wetlands, rice paddies are to date pooled with cereals in guidance documents on how to conduct risk assessments for birds and mammals in Europe. Hence, the focal species currently considered in risk assessments for rice paddies are those known from cereal fields and can therefore be expected to differ significantly from the species actually occurring in the wet environments of rice paddies. We present results of a comprehensive review on bird and mammal species regularly occurring in rice paddies during a time of potential pesticide exposure to identify appropriate focal species candidates for ecotoxicological pesticide risk assessment according to the European Food Safety Authority (EFSA). In addition, we present data on rice cultivation areas and agricultural practices in Europe to give background information supporting the species selection process. Our literature search identified a general scarcity of relevant data, particularly for mammals, which highlights the need for crop-specific focal species studies. However, our results clearly indicate that the relevant bird and mammal species in rice fields indeed differ strongly from the focal species used for the cereal risk assessment. They can thus be used as a baseline for more realistic wildlife risk assessments specific to rice and the development of a revised guidance document to bridge the gap for regulatory decision makers. Integr Environ Assess Manag 2018;00:000-000. © 2018 SETAC. © 2018 SETAC.

  4. Morphoagronomic genetic diversity in american wild rice species

    Directory of Open Access Journals (Sweden)

    Elizabeth Ann Veasey

    2008-02-01

    Full Text Available To characterize the genetic variability among species and populations of South American wild rice, eleven populations of Oryza glumaepatula, seven of O. grandiglumis, four of O. latifolia and one of O. alta, from Brazil and Argentina, were evaluated. A greenhouse experiment was conducted in completely randomized blocks with 23 treatments. Twenty morphoagronomic traits were assessed. Univariate analyses were performed with 16 quantitative traits with the partitioning of populations within species. Significant differences (pVisando caracterizar a diversidade genética entre espécies e populações de arroz selvagem da América do Sul, foram avaliadas 11 populações de Oryza glumaepatula, sete de O. grandiglumis, quatro de O. latifolia e uma população de O. alta, originárias do Brasil e Argentina. Foi conduzido um experimento em casa-de-vegetação em blocos ao acaso com 23 tratamentos. Vinte caracteres agro-morfológicos foram avaliados. Análises univariadas foram realizadas para 16 caracteres quantitativos, desdobrando-se o efeito de populações dentro de espécies. Diferenças significativas (p<0,001 entre espécies foram observadas para todos os caracteres bem como entre populações dentro de espécies. A mais variável foi O. glumaepatula seguida de O. latifolia. Análises de agrupamento e discriminante canônica confirmaram a separação das populações de O. glumaepatula das espécies tetraplóides, e a grande variação genética entre populações de O. latifolia. Diferenças morfológicas entre as três espécies tetraplóides parecem suficientes para classificá-las como espécies pelo menos na condição statu nascendi.

  5. Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

    Science.gov (United States)

    Selenium (Se) is an essential micronutrient in which up to 1 billion people worldwide are deficient, causing a range of health disorders and potentially an increased risk of certain cancers. Consequently, there is much interest in Se biofortification of rice, the staple food for...

  6. Karyotype Stability and Unbiased Fractionation in the Paleo-Allotetraploid Cucurbita Genomes.

    Science.gov (United States)

    Sun, Honghe; Wu, Shan; Zhang, Guoyu; Jiao, Chen; Guo, Shaogui; Ren, Yi; Zhang, Jie; Zhang, Haiying; Gong, Guoyi; Jia, Zhangcai; Zhang, Fan; Tian, Jiaxing; Lucas, William J; Doyle, Jeff J; Li, Haizhen; Fei, Zhangjun; Xu, Yong

    2017-10-09

    The Cucurbita genus contains several economically important species in the Cucurbitaceae family. Here, we report high-quality genome sequences of C. maxima and C. moschata and provide evidence supporting an allotetraploidization event in Cucurbita. We are able to partition the genome into two homoeologous subgenomes based on different genetic distances to melon, cucumber, and watermelon in the Benincaseae tribe. We estimate that the two diploid progenitors successively diverged from Benincaseae around 31 and 26 million years ago (Mya), respectively, and the allotetraploidization happened at some point between 26 Mya and 3 Mya, the estimated date when C. maxima and C. moschata diverged. The subgenomes have largely maintained the chromosome structures of their diploid progenitors. Such long-term karyotype stability after polyploidization has not been commonly observed in plant polyploids. The two subgenomes have retained similar numbers of genes, and neither subgenome is globally dominant in gene expression. Allele-specific expression analysis in the C. maxima × C. moschata interspecific F 1 hybrid and their two parents indicates the predominance of trans-regulatory effects underlying expression divergence of the parents, and detects transgressive gene expression changes in the hybrid correlated with heterosis in important agronomic traits. Our study provides insights into polyploid genome evolution and valuable resources for genetic improvement of cucurbit crops. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

  7. Effect of organic matter amendment, arsenic amendment and water management regime on rice grain arsenic species

    International Nuclear Information System (INIS)

    Norton, Gareth J.; Adomako, Eureka E.; Deacon, Claire M.; Carey, Anne-Marie; Price, Adam H.; Meharg, Andrew A.

    2013-01-01

    Arsenic accumulation in rice grain has been identified as a major problem in some regions of Asia. A study was conducted to investigate the effect of increased organic matter in the soil on the release of arsenic into soil pore water and accumulation of arsenic species within rice grain. It was observed that high concentrations of soil arsenic and organic matter caused a reduction in plant growth and delayed flowering time. Total grain arsenic accumulation was higher in the plants grown in high soil arsenic in combination with high organic matter, with an increase in the percentage of organic arsenic species observed. The results indicate that the application of organic matter should be done with caution in paddy soils which have high soil arsenic, as this may lead to an increase in accumulation of arsenic within rice grains. Results also confirm that flooding conditions substantially increase grain arsenic. -- Highlights: ► High soil arsenic and organic matter caused a reduction in plant growth. ► A delayed flowering time was observed in high arsenic and organic matter soil. ► Total grain arsenic increased in high arsenic and organic matter soil. ► Percentage organic arsenic in the grain altered in arsenic and organic matter soil. -- The addition of high amounts of organic matter to soils led to an increase in total rice grain arsenic, as well as alteration in the percentage arsenic species in the rice grains

  8. Microbial Species and Functional Diversity in Rice Rhizosphere of High-yield Special Ecological Areas

    Directory of Open Access Journals (Sweden)

    PAN Li-yuan

    2016-11-01

    Full Text Available Taoyuan, Yunnan Province is a special eco-site which keeps the highest yield records of rice cultivation in small planting areas. Soil microbial species and functional diversity were evaluated using cultivation method and BIOLOG ecoplates. The results showed that the microbial community of the high yield region was more abundant, and the total microbial population was 2 times of the control, furthermore, the areas belonged to the healthy "bacteria" soil, which was showed as bacteria > actinomycetes > fungi. Bacteria were the dominant populations in the rhizosphere of high yielding rice field, and the yield formation of rice was not correlated with the depth of soil layers. In order to obtain more species diversity information, Shannon diversity index H, Shannon evenness index E and Simpson index D were analyzed, and the results showed that microbial community diversity and evenness were not the main differences between the high and general yield areas. Then, the functional diversity of soil microbial community was investigated through the average well color development(AWCD and diversity index analyses. The results of AWCD analysis indicated that the metabolic activity of soil microbial community in high yield paddy soils were stronger than the control. Moreover, the difference range from large to small showed as tillering stage > harvest period > seedling period > rotation period, the stronger the rice growth, the greater the difference between the high yield region and the control. At tillering stage and harvest stage, due to the vigorous plant growth, the root exudates were rich, and the microbial communities of high yield paddy soils showed a strong metabolic activity and strong ability to use carbon sources. The results of Shannon, Simpson and McIntosh indices analysis indicated that common microbial species was not a key factor affecting the yield of rice. Tillering stage was a key period for the growth of high yield rice, and many

  9. Allotetraploid origin and divergence in Eleusine (Chloridoideae, Poaceae): evidence from low-copy nuclear gene phylogenies and a plastid gene chronogram.

    Science.gov (United States)

    Liu, Qing; Triplett, Jimmy K; Wen, Jun; Peterson, Paul M

    2011-11-01

    Eleusine (Poaceae) is a small genus of the subfamily Chloridoideae exhibiting considerable morphological and ecological diversity in East Africa and the Americas. The interspecific phylogenetic relationships of Eleusine are investigated in order to identify its allotetraploid origin, and a chronogram is estimated to infer temporal relationships between palaeoenvironment changes and divergence of Eleusine in East Africa. Two low-copy nuclear (LCN) markers, Pepc4 and EF-1α, were analysed using parsimony, likelihood and Bayesian approaches. A chronogram of Eleusine was inferred from a combined data set of six plastid DNA markers (ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3, and rpl32-trnL) using the Bayesian dating method. The monophyly of Eleusine is strongly supported by sequence data from two LCN markers. In the cpDNA phylogeny, three tetraploid species (E. africana, E. coracana and E. kigeziensis) share a common ancestor with the E. indica-E. tristachya clade, which is considered a source of maternal parents for allotetraploids. Two homoeologous loci are isolated from three tetraploid species in the Pepc4 phylogeny, and the maternal parents receive further support. The A-type EF-1α sequences possess three characters, i.e. a large number of variations of intron 2; clade E-A distantly diverged from clade E-B and other diploid species; and seven deletions in intron 2, implying a possible derivation through a gene duplication event. The crown age of Eleusine and the allotetraploid lineage are 3·89 million years ago (mya) and 1·40 mya, respectively. The molecular data support independent allotetraploid origins for E. kigeziensis and the E. africana-E. coracana clade. Both events may have involved diploids E. indica and E. tristachya as the maternal parents, but the paternal parents remain unidentified. The habitat-specific hypothesis is proposed to explain the divergence of Eleusine and its allotetraploid lineage.

  10. Determination of sixteen elements and arsenic species in brown, polished and milled rice.

    Science.gov (United States)

    Narukawa, Tomohiro; Matsumoto, Eri; Nishimura, Tsutomu; Hioki, Akiharu

    2014-01-01

    The concentrations of 16 elements in 10 rice flour samples and the distribution of the elements in the rice grains from which the flour were made were determined by ICP-MS and ICP-OES after microwave-assisted digestion of the samples. Arsenic speciation analysis was carried out by HPLC-ICP-MS following heat-assisted extraction of the sample. The concentrations of inorganic As (As(III) and As(V)), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) and their distribution in the rice grains were determined. Portions of the brown rice were polished/milled to different degrees to yield milled off samples and polished rice samples. All samples were powdered and analyzed for 16 elements and for As species. The recoveries and mass balances for all elements in all samples showed good agreements with the starting materials. As(III), As(V), MMAA and DMAA were detected, and the sums of the concentrations of all species in the extract were 86-105% of the total As concentration in each case.

  11. Ecogeographic variation in the morphology of two Asian wild rice species Oryza nivara and O. ruftipogon.

    NARCIS (Netherlands)

    Banaticla, M.C.N.; Sosef, M.S.M.; McNally, K.L.; Sackville Hamilton, R.; Berg, van den R.G.

    2013-01-01

    To search for variation patterns and diagnostic features between Asian wild rice species, several numerical methods were applied to phenotypic data obtained from 116 accessions representing sympatric populations of Oryza nivara and Oryza rufipogon from tropical continental Asia and O. rufipogon

  12. Arsenic species in wheat, raw and cooked rice: Exposure and associated health implications.

    Science.gov (United States)

    Rasheed, Hifza; Kay, Paul; Slack, Rebecca; Gong, Yun Yun

    2018-09-01

    Arsenic concentrations above 10μgL -1 were previously found in 89% of ground water sources in six villages of Pakistan. The present study has ascertained the health risks associated with exposure to total arsenic (tAs) and its species in most frequently consumed foods. Inorganic arsenic (iAs) concentrations were found to be 92.5±41.88μgkg -1 , 79.21±76.42μgkg -1 , and 116.38±51.38μgkg -1 for raw rice, cooked rice and wheat respectively. The mean tAs concentrations were 47.47±30.72μgkg -1 , 71.65±74.7μgkg -1 , 105±61.47μgkg -1 . Wheat is therefore demonstrated to be a significant source of arsenic exposure. Dimethylarsinic acid was the main organic species detected in rice, whilst monomethylarsonic acid was only found at trace levels. Total daily intake of iAs exceeded the provisional tolerable daily intake of 2.1μgkg -1 day -1 body weight in 74% of study participants due to concurrent intake from water (94%), wheat (5%) and raw rice (1%). A significant association between tAs in cooked rice and cooking water resulted in tAs intake 43% higher in cooked rice compared to raw rice. The study suggests that arsenic intake from food, particularly from wheat consumption, holds particular significance where iAs is relatively low in water. Chronic health risks were found to be significantly higher from wheat intake than rice, whilst the risk in terms of acute effects was below the USEPA's limit of 1.0. Children were at significantly higher health risk than adults due to iAs exposure from rice and/or wheat. The dietary exposure of participants to tAs was attributable to staple food intake with ground water iAs iAs in drinking water. Although the daily iAs intake from food was lower than total water intake, the potential health risk from exposure to arsenic and its species still exists and requires exposure control measures. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Comparison of arsenic uptake ability of barnyard grass and rice species for arsenic phytoremediation.

    Science.gov (United States)

    Sultana, Razia; Kobayashi, Katsuichiro; Kim, Ki-Hyun

    2015-01-01

    In this research, the relative performance in arsenic (As) remediation was evaluated among some barnyard grass and rice species under hydroponic conditions. To this end, four barnyard grass varieties and two rice species were selected and tested for their remediation potential of arsenic. The plants were grown for 2 weeks in As-rich solutions up to 10 mg As L(-1) to measure their tolerance to As and their uptake capabilities. Among the varieties of plants tested in all treatment types, BR-29 rice absorbed the highest amount of As in the root, while Nipponbare translocated the maximum amount of As in the shoot. Himetainubie barnyard grass produced the highest biomass, irrespective of the quantity of As in the solution. In all As-treated solutions, the maximum uptake of As was found in BR-29 followed by Choto shama and Himetainubie. In contrast, while the bioaccumulation factor was found to be the highest in Nipponbare followed by BR-29 and Himetainubie. The results suggest that both Choto shama and Himetainubie barnyard grass varieties should exhibit a great potential for As removal, while BR-29 and Nipponbare rice species are the best option for arsenic phytoremediation.

  14. Study on Analysis of Variance on the indigenous wild and cultivated rice species of Manipur Valley

    Science.gov (United States)

    Medhabati, K.; Rohinikumar, M.; Rajiv Das, K.; Henary, Ch.; Dikash, Th.

    2012-10-01

    The analysis of variance revealed considerable variation among the cultivars and the wild species for yield and other quantitative characters in both the years of investigation. The highly significant differences among the cultivars in year wise and pooled analysis of variance for all the 12 characters reveal that there are enough genetic variabilities for all the characters studied. The existence of genetic variability is of paramount importance for starting a judicious plant breeding programme. Since introduced high yielding rice cultivars usually do not perform well. Improvement of indigenous cultivars is a clear choice for increase of rice production. The genetic variability of 37 rice germplasms in 12 agronomic characters estimated in the present study can be used in breeding programme

  15. Biological control of rice brown spot with native isolates of three Trichoderma species

    Directory of Open Access Journals (Sweden)

    Elham Khalili

    2012-03-01

    Full Text Available Brown spot caused by Bipolaris oryzae is an important rice disease in Southern coast of Caspian Sea, the major rice growing region in Iran. A total of 45 Trichoderma isolates were obtained from rice paddy fields in Golestan and Mazandaran provinces which belonged to Trichoderma harzianum, T. virens and T. atroviride species. Initially, they were screened against B. oryzae by antagonism tests including dual culture, volatile and nonvolatile metabolites and hyperparasitism. Results showed that Trichoderma isolates can significantly inhibit mycelium growth of pathogen in vitro by producing volatile and nonvolatile metabolites Light microscopic observations showed no evidence of mycoparasitic behaviour of the tested isolates of Trichoderma spp. such as coiling around the B. oryzae. According to in vitro experiments, Trichoderma isolates were selected in order to evaluate their efficacy in controlling brown spot in glasshouse using seed treatment and foliar spray methods. Concerning the glasshouse tests, two strains of T. harzianum significantly controlled the disease and one strain of T. atroviride increased the seedling growth. It is the first time that the biological control of rice brown spot and increase of seedling growth with Trichoderma species have been studied in Iran.

  16. Determination of plant species for the phytoremediation of carbofuran residue in rice field soils

    Directory of Open Access Journals (Sweden)

    Alissara Reungsang

    2005-09-01

    Full Text Available This study searched for plant species suitable for accumulating carbofuran residue in rice field soil. Three groups of plant, i.e. grass crops, upland crops, and vegetable crops, were grown in 8 inches diameter plastic pots filled with soil containing 5 mg/kg carbofuran. Parts of plants (stems and leaves, roots, fruits were harvested at day 120 and analyzed for carbofuran residue using HPLC. The results indicated that Helianthus annuus L. (sunflower was the most suitable species for phytoremediation of carbofuran residue in rice field soil because it highly accumulated carbofuran up to 93.4 μg/kg dry weight in its stems and leaves. In addition, H. annuus L. (sunflower could tolerate carbofuran since it showed similar physical appearance (circumference and height to control not receiving carbofuran.

  17. Different localization patterns of anthocyanin species in the pericarp of black rice revealed by imaging mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Yukihiro Yoshimura

    Full Text Available Black rice (Oryza sativa L. Japonica contains high levels of anthocyanins in the pericarp and is considered an effective health-promoting food. Several studies have identified the molecular species of anthocyanins in black rice, but information about the localization of each anthocyanin species is limited because methodologies for investigating the localization such as determining specific antibodies to anthocyanin, have not yet been developed Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS is a suitable tool for investigating the localization of metabolites. In this study, we identified 7 species of anthocyanin monoglycosides and 2 species of anthocyanin diglycosides in crude extracts from black rice by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS analysis. We also analyzed black rice sections by MALDI-IMS and found 2 additional species of anthocyanin pentosides and revealed different localization patterns of anthocyanin species composed of different sugar moieties. Anthocyanin species composed of a pentose moiety (cyanidin-3-O-pentoside and petunidin-3-O-pentoside were localized in the entire pericarp, whereas anthocyanin species composed of a hexose moiety (cyanidin-3-O-hexoside and peonidin-3-O-hexoside were focally localized in the dorsal pericarp. These results indicate that anthocyanin species composed of different sugar moieties exhibit different localization patterns in the pericarp of black rice. This is the first detailed investigation into the localization of molecular species of anthocyanins by MALDI-IMS.

  18. Growth promotion and inhibition of the Amazonian wild rice species Oryza grandiglumis to survive flooding.

    Science.gov (United States)

    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.

  19. Characterization of mercury species in brown and white rice (Oryza sativa L.) grown in water-saving paddies

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, Sarah E., E-mail: rothenberg.sarah@gmail.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Feng Xinbin, E-mail: fengxinbin@vip.skleg.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Dong Bin, E-mail: dongbin@whu.edu.cn [State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 (China); Shang Lihai, E-mail: shanglihai@vip.gyig.ac.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Yin Runsheng, E-mail: yinrunsheng2002@163.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Yuan Xiaobo, E-mail: xiantao_131@163.com [College of Resources and the Environment, Southwest University, Chongqing 400716 (China)

    2011-05-15

    In China, total Hg (Hg{sub T}) and methylmercury (MeHg) were quantified in rice grain grown in three sites using water-saving rice cultivation methods, and in one Hg-contaminated site, where rice was grown under flooded conditions. Polished white rice concentrations of Hg{sub T} (water-saving: 3.3 {+-} 1.6 ng/g; flooded: 110 {+-} 9.2 ng/g) and MeHg (water-saving 1.3 {+-} 0.56 ng/g; flooded: 12 {+-} 2.4 ng/g) were positively correlated with root-soil Hg{sub T} and MeHg contents (Hg{sub T}: r{sup 2} = 0.97, MeHg: r{sup 2} = 0.87, p < 0.05 for both), which suggested a portion of Hg species in rice grain was derived from the soil, and translocation of Hg species from soil to rice grain was independent of irrigation practices and Hg levels, although other factors may be important. Concentrations of Hg{sub T} and other trace elements were significantly higher in unmilled brown rice (p < 0.05), while MeHg content was similar (p > 0.20), indicating MeHg infiltrated the endosperm (i.e., white rice) more efficiently than inorganic Hg(II). - Highlights: > First time that Hg{sub T} and MeHg were characterized in both brown and white rice. > MeHg translocation into the endosperm was more efficient than inorganic Hg(II). > In this respect, MeHg behaved like dimethylarsinic acid and organic Se species. > In white rice, Hg{sub T} and MeHg were positively correlated with soil Hg{sub T} and MeHg. > Uptake rates of Hg{sub T} and MeHg were independent of irrigation methods and Hg content. - Methylmercury was more efficiently translocated to the endosperm than inorganic mercury.

  20. Evaluating the non-rice host plant species of Sesamia inferens (Lepidoptera: Noctuidae) as natural refuges: resistance management of Bt rice.

    Science.gov (United States)

    Liu, Zhuorong; Gao, Yulin; Luo, Ju; Lai, Fengxiang; Li, Yunhe; Fu, Qiang; Peng, Yufa

    2011-06-01

    Although rice (Oryza sativa L.) lines that express Bacillus thuringiensis (Bt) toxins have shown great potential for managing the major Lepidoptera pests of rice in southern China, including Sesamia inferens, their long-term use is dependent on managing resistance development to Bt toxins in pest populations. The maintenance of "natural" refuges, non-Bt expressing plants that are hosts for a target pest, has been proposed as a means to minimize the evolution of resistance to Bt toxins in transgenic plants. In the current study, field surveys and greenhouse experiments were conducted to identify host plants of S. inferens that could serve as "natural" refuges in rice growing areas of southern China. A field survey showed that 34 plant species in four families can be alternative host plants of S. inferens. Based on injury level under field conditions, rice (Oryza sativa L.); water oat (Zizania latifolia Griseb.); corn (Zea mays L.); tidalmarsh flatsedge (Cyperus serotinus Rottb.); and narrow-leaved cat-tail (Typha angustifolia Linn.) were identified as the primary host plant species of S. inferens. Greenhouse experiments further demonstrated that water oat, corn, and narrow-leaved cat-tail could support the survival and development of S. inferens. Interestingly, greenhouse experiments showed that S. inferens preferred to lay eggs on tidalmarsh flatsedge compared with the other three nonrice host species, although no pupae were found in the plants examined in field surveys. Few larvae were found to survive on tidalmarsh flatsedge in greenhouse bioassays, suggesting that tidalmarsh flatsedge could serve as a "dead-end" trap crop for S. inferens, but is not a candidate to serve as natural refuge to maintain susceptible S. inferens. Overall, these results suggest that water-oat, corn, and narrow-leaved cat-tail might serve as "natural refuge" for S. inferens in rice planting area of southern China when Bt rice varieties are planted.

  1. Mitochondrial Genome Analysis of Wild Rice (Oryza minuta) and Its Comparison with Other Related Species.

    Science.gov (United States)

    Asaf, Sajjad; Khan, Abdul Latif; Khan, Abdur Rahim; Waqas, Muhammad; Kang, Sang-Mo; Khan, Muhammad Aaqil; Shahzad, Raheem; Seo, Chang-Woo; Shin, Jae-Ho; Lee, In-Jung

    2016-01-01

    Oryza minuta (Poaceae family) is a tetraploid wild relative of cultivated rice with a BBCC genome. O. minuta has the potential to resist against various pathogenic diseases such as bacterial blight (BB), white backed planthopper (WBPH) and brown plant hopper (BPH). Here, we sequenced and annotated the complete mitochondrial genome of O. minuta. The mtDNA genome is 515,022 bp, containing 60 protein coding genes, 31 tRNA genes and two rRNA genes. The mitochondrial genome organization and the gene content at the nucleotide level are highly similar (89%) to that of O. rufipogon. Comparison with other related species revealed that most of the genes with known function are conserved among the Poaceae members. Similarly, O. minuta mt genome shared 24 protein-coding genes, 15 tRNA genes and 1 ribosomal RNA gene with other rice species (indica and japonica). The evolutionary relationship and phylogenetic analysis revealed that O. minuta is more closely related to O. rufipogon than to any other related species. Such studies are essential to understand the evolutionary divergence among species and analyze common gene pools to combat risks in the current scenario of a changing environment.

  2. Insights into the Musa genome: Syntenic relationships to rice and between Musa species

    Directory of Open Access Journals (Sweden)

    Althoff Ryan

    2008-01-01

    Full Text Available Abstract Background Musa species (Zingiberaceae, Zingiberales including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning Musa genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no large-scale analyses of Musa genomic sequence have been conducted. This study compares genomic sequence in two Musa species with orthologous regions in the rice genome. Results We produced 1.4 Mb of Musa sequence from 13 BAC clones, annotated and analyzed them along with 4 previously sequenced BACs. The 443 predicted genes revealed that Zingiberales genes share GC content and distribution characteristics with eudicot and Poaceae genomes. Comparison with rice revealed microsynteny regions that have persisted since the divergence of the Commelinid orders Poales and Zingiberales at least 117 Mya. The previously hypothesized large-scale duplication event in the common ancestor of major cereal lineages within the Poaceae was verified. The divergence time distributions for Musa-Zingiber (Zingiberaceae, Zingiberales orthologs and paralogs provide strong evidence for a large-scale duplication event in the Musa lineage after its divergence from the Zingiberaceae approximately 61 Mya. Comparisons of genomic regions from M. acuminata and M. balbisiana revealed highly conserved genome structure, and indicated that these genomes diverged circa 4.6 Mya. Conclusion These results point to the utility of comparative analyses between distantly-related monocot species such as rice and Musa for improving our understanding of monocot genome evolution. Sequencing the genome of M. acuminata would provide a strong foundation for comparative genomics in the monocots. In addition a genome sequence would aid genomic and genetic analyses of cultivated Musa polyploid genotypes in research aimed at localizing and cloning genes controlling important agronomic

  3. Extraction techniques for arsenic species in rice flour and their speciation by HPLC-ICP-MS.

    Science.gov (United States)

    Narukawa, Tomohiro; Suzuki, Toshihiro; Inagaki, Kazumi; Hioki, Akiharu

    2014-12-01

    The extraction of arsenic (As) species present in rice flour samples was investigated using different extracting solvents, and the concentration of each species was determined by HPLC-ICP-MS after heat-assisted extraction. The extraction efficiencies for total arsenic species and especially for arsenite [As(III)] and arsenate [As(V)] were investigated. As(III), As(V) and dimethylarsinic acid (DMAA) were found in the samples, and the concentration of DMAA did not vary with treatment conditions. However, the concentrations of extracted total arsenic and those of As(III) and As(V) depended on the extracting solvents. When an extracting solvent was highly acidic, the concentrations of extracted total arsenic were in good agreement with the total arsenic concentration determined by ICP-MS after microwave-assisted digestion, though a part of the As(V) was reduced to As(III) during the highly acidic extraction process. Extraction under neutral conditions increased the extracted As(V), but extracted total arsenic was decreased because a part of the As(III) could not be extracted. Optimum conditions for the extraction of As(III) and As(V) from rice flour samples are discussed to allow the accurate determinations of As(III), As(V) and DMAA in the rice flour samples. Heat block extraction techniques using 0.05 mol L(-1) HClO4 and silver-containing 0.15 mol L(-1) HNO3 were also developed. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Efficient engineering of marker-free synthetic allotetraploids of Saccharomyces.

    Science.gov (United States)

    Alexander, William G; Peris, David; Pfannenstiel, Brandon T; Opulente, Dana A; Kuang, Meihua; Hittinger, Chris Todd

    2016-04-01

    Saccharomyces interspecies hybrids are critical biocatalysts in the fermented beverage industry, including in the production of lager beers, Belgian ales, ciders, and cold-fermented wines. Current methods for making synthetic interspecies hybrids are cumbersome and/or require genome modifications. We have developed a simple, robust, and efficient method for generating allotetraploid strains of prototrophic Saccharomyces without sporulation or nuclear genome manipulation. S. cerevisiae×S. eubayanus, S. cerevisiae×S. kudriavzevii, and S. cerevisiae×S. uvarum designer hybrid strains were created as synthetic lager, Belgian, and cider strains, respectively. The ploidy and hybrid nature of the strains were confirmed using flow cytometry and PCR-RFLP analysis, respectively. This method provides an efficient means for producing novel synthetic hybrids for beverage and biofuel production, as well as for constructing tetraploids to be used for basic research in evolutionary genetics and genome stability. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Cytomolecular analysis of ribosomal DNA evolution in a natural allotetraploid Brachypodium hybridum and its putative ancestors – dissecting complex repetitive structure of intergenic spacers

    Directory of Open Access Journals (Sweden)

    Natalia Borowska-Zuchowska

    2016-10-01

    Full Text Available Nucleolar dominance is an epigenetic phenomenon associated with nuclear 35S rRNA genes and consists in selective suppression of gene loci inherited from one of the progenitors in the allopolyploid. Our understanding of the exact mechanisms that determine this process is still fragmentary, especially in case of the grass species. This study aimed to shed some light on the molecular basis of this genome-specific inactivation of 35S rDNA loci in an allotetraploid Brachypodium hybridum (2n=30, which arose from the interspecific hybridization between two diploid ancestors that were very similar to modern B. distachyon (2n=10 and B. stacei (2n=20. Using fluorescence in situ hybridization with 25S rDNA and chromosome-specific BAC clones as probes we revealed that the nucleolar dominance is present not only in meristematic root-tip cells but also in differentiated cell fraction of B. hybridum. Additionally, the intergenic spacers (IGSs from both of the putative ancestors and the allotetraploid were sequenced and analyzed. The presumptive transcription initiation sites, spacer promoters and repeated elements were identified within the IGSs. Two different length variants, 2.3 kb and 3.5 kb, of IGSs were identified in B. distachyon and B. stacei, respectively, however only the IGS that had originated from B. distachyon-like ancestor was present in the allotetraploid. The amplification pattern of B. hybridum IGSs suggests that some genetic changes occurred in inactive B. stacei-like rDNA loci during the evolution of the allotetraploid. We hypothesize that their preferential silencing is an effect of structural changes in the sequence rather than just the result of the sole inactivation at the epigenetic level.

  6. Morphological identification of Candida species on glucose agar, rice extract agar and corn meal agar with and without Tween-80.

    Science.gov (United States)

    Joshi, K R; Solanki, A; Prakash, P

    1993-01-01

    A comparative study for the identification of 32 known strains of Candida species on the basis of morphology on glucose agar, rice extract agar and corn meal agar with and without Tween 80 revealed that when Tween 80 is incorporated in the media identification is possible for 96.8% of the species within 48 hours on rice extract agar and for 96.8% of the species within 48 hours on rice extract agar and for 90.6% of the species on glucose agar. The germ tubes and chlamydospores were also produced more on rice extract agar than on 0.1% glucose agar. Rice extract agar with Tween 80 can be used as single medium for morphologic identification of Candida species. The inoculated medium is first incubated at 37 degrees C for 3 hours and examined for germ tube formation and then incubated at 25 degrees C for 24 to 72 hours and examined for appearance of chlamydospores and mycelial morphology.

  7. Yield-enhancing heterotic QTL transferred from wild species to cultivated rice Oryza sativa L.

    Science.gov (United States)

    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.

  8. Comparative analysis of the transcriptional responses to low and high temperatures in three rice planthopper species.

    Science.gov (United States)

    Huang, Hai-Jian; Xue, Jian; Zhuo, Ji-Chong; Cheng, Ruo-Lin; Xu, Hai-Jun; Zhang, Chuan-Xi

    2017-05-01

    The brown planthopper (Nilaparvata lugens, BPH), white-backed planthopper (Sogatella furcifera, WBPH) and small brown planthopper (Laodelphax striatellus, SBPH) are important rice pests in Asia. These three species differ in thermal tolerance and exhibit quite different migration and overwintering strategies. To understand the underlying mechanisms, we sequenced and compared the transcriptome of the three species under different temperature treatments. We found that metabolism-, exoskeleton- and chemosensory-related genes were modulated. In high temperature (37 °C), heat shock protein (HSP) genes were the most co-regulated; other genes related with fatty acid metabolism, amino acid metabolism and transportation were also differentially expressed. In low temperature (5 °C), the differences in gene expression of the genes for fatty acid synthesis, transport proteins and cytochrome P450 might explain why SBPH can overwinter in high latitudes, while BPH and WBPH cannot. In addition, other genes related with moulting, and membrane lipid composition might also play roles in resistance to low and high temperatures. Our study illustrates the common responses and different tolerance mechanisms of three rice planthoppers in coping with temperature change, and provides a potential strategy for pest management. © 2017 John Wiley & Sons Ltd.

  9. Molecular identification of Aspergillus and Eurotium species isolated from rice and their toxin-producing ability.

    Science.gov (United States)

    Yazdani, D; Zainal Abidin, M A; Tan, Y H; Kamaruzaman, S

    2011-01-01

    Thirty milled rice samples were collected from retailers in 4 provinces of Malaysia. These samples were evaluated for Aspergillus spp. infection by direct plating on malt extract salt agar (MESA). All Aspergillus holomorphs were isolated and identified using nucleotide sequences of ITS 1 and ITS 2 of rDNA. Five anamorphs (Aspergillus flavus, A. oryzae, A. tamarii, A. fumigatus and A. niger) and 5 teleomorphs (Eurotium rubrum, E. amstelodami, E. chevalieri, E. cristatum and E. tonophilum) were identified. The PCR-sequencing based technique for sequences of ITS 1 and ITS 2 is a fast technique for identification of Aspergillus and Eurotium species, although it doesn't work flawlessly for differentiation of Eurotium species. All Aspergillus and Eurotium isolates were screened for their ability to produce aflatoxin and ochratoxin A (OTA) by HPLC and TLC techniques. Only A. flavus isolate UPM 89 was able to produce aflatoxins B1 and B2.

  10. Analytical method for the determination of various arsenic species in rice, rice food products, apple juice, and other juices by ion chromatography-inductively coupled plasma/mass spectrometry.

    Science.gov (United States)

    Ellingson, David; Zywicki, Richard; Sullivan, Darryl

    2014-01-01

    Recent studies have shown that there are detectable levels of arsenic (As) in rice, rice food products, and apple juice. This has created significant concern to the public, the food industry, and various regulatory bodies. Classic test methods typically measure total As and are unable to differentiate the various As species. Since different As species have greatly different toxicities, an analytical method was needed to separate and quantify the different inorganic and organic species of As. The inorganic species arsenite [As(+3)] and arsenate [As(+5)] are highly toxic. With this in mind, an ion chromatography-inductively coupled plasma (IC-ICP/MS) method was developed and validated for rice and rice food products that can separate and individually measure multiple inorganic and organic species of As. This allows for the evaluation of the safety or risk associated with any product analyzed. The IC-ICP/MS method was validated on rice and rice food products, and it has been used successfully on apple juice. This paper provides details of the validated method as well as some lessons learned during its development. Precision and accuracy data are presented for rice, rice food products, and apple juice.

  11. The new species Enterobacter oryziphilus sp. nov. and Enterobacter oryzendophyticus sp. nov. are key inhabitants of the endosphere of rice

    Science.gov (United States)

    2013-01-01

    Background Six independent Gram-negative, facultatively anaerobic, non-spore-forming, nitrogen-fixing rod-shaped isolates were obtained from the root endosphere of rice grown at the International Rice Research Institute (IRRI) and investigated in a polyphasic taxonomic study. Results The strains produced fatty acid patterns typical for members of the family Enterobacteriaceae. Comparative sequence analyses of the 16S rRNA as well as rpoB genes allocated the strains to two well-defined groups within the genus Enterobacter, family Enterobacteriaceae. The analyses indicated Enterobacter radicincitans, Enterobacter arachidis and Enterobacter oryzae to be the closest related species. An RpoB (translated) protein comparison supported the placement in the genus Enterobacter and the relatedness of our isolates to the aforementioned species. Genomic DNA:DNA hybridization analyses and biochemical analyses provided further evidence that the novel strains belong to two new species within the genus Enterobacter. The two species can be differentiated from each other and from existing enteric species by acid production from L-rhamnose and D-melibiose, decarboxylation of ornithine and utilization of D-alanine, D-raffinose L-proline and L-aspartic acid, among other characteristics. Members of both species revealed capacities to colonise rice roots, including plant-growth-promoting capabilities such as an active supply of fixed nitrogen to the plant and solubilisation of inorganic phosphorus, next to traits allowing adaptation to the plant. Conclusions Two novel proposed enterobacterial species, denominated Enterobacter oryziphilus sp. nov. (type strain REICA_142T=LMG 26429T=NCCB 100393T) and Enterobacter oryzendophyticus sp. nov. (type strain REICA_082T=LMG 26432T =NCCB 100390T) were isolated from rice roots. Both species are capable of promoting rice growth by supplying nitrogen and phosphorus. PMID:23865888

  12. Characterization of seeds of selected wild species of rice (Oryza) stored under high temperature and humidity conditions.

    Science.gov (United States)

    Das, Smruti; Nayak, Monalisa; Patra, B C; Ramakrishnan, B; Krishnan, P

    2010-06-01

    Wild progenitors of rice (Oryza) are an invaluable resource for restoring genetic diversity and incorporating useful traits back into cultivars. Studies were conducted to characterize the biochemical changes, including SDS-PAGE banding pattern of storage proteins in seeds of six wild species (Oryza alta, O. grandiglumis, O. meridionalis, O. nivara, O. officinalis and O. rhizomatis) of rice stored under high temperature (45 degrees C) and humidity (approixmately 100%) for 15 days, which facilitated accelerated deterioration. Under the treated conditions, seeds of different wild rice species showed decrease in per cent germination and concentrations of protein and starch, but increase in conductivity of leachate and content of sugar. The SDS-PAGE analysis of seed proteins showed that not only the total number of bands, but also their intensity in terms of thickness differed for each species under storage. The total number of bands ranged from 11 to 22, but none of the species showed all the bands. Similarity index for protein bands between the control and treated seeds was observed to be least in O. rhizomatis and O. alta, while the indices were 0.7 and 0.625 for O. officinalis and O. nivara, respectively. This study clearly showed that seed deterioration led to distinctive biochemical changes, including the presence or absence as well as altered levels of intensity of proteins. Hence, SDS-PAGE protein banding pattern can be used effectively to characterize deterioration of seeds of different wild species of rice.

  13. Parallel female preferences for call duration in a diploid ancestor of an allotetraploid treefrog.

    Science.gov (United States)

    Bee, Mark A

    2008-09-01

    The gray treefrog species complex (Hyla chrysoscelis and H. versicolor) comprises a single allotetraploid species (H. versicolor) that arose multiple times from hybrid matings between an extant diploid species (H. chrysoscelis) and at least two other extinct diploid treefrogs. While previous studies have investigated female preferences for call duration in the tetraploid, we know little about these preferences in its putative diploid anscestors. Here, I report results from two-choice phonotaxis experiments investigating call duration preferences in H. chrysoscelis. Females preferred an average-length call over shorter-than-average calls (0.5-2.0 standard deviations [SD] below average), and they preferred longer-than-average calls over average or shorter-than-average calls if the difference in pulse number was at least 2.0 SD. When the amplitude of the longer alternative was attenuated by 6 dB, females still preferred an average-length call over a shorter-than-average call, but there was no preference for longer-than-average calls over an average call. In the presence of chorus noise, female preferences for both average and longer-than-average calls over shorter alternatives were weakened or reversed. Together, the results from this study reveal patterns of female preferences for call duration that are strikingly similar among two members of a species complex with a novel evolutionary history. In both species, female preferences are directional, nonlinear, and limited by environmental noise. Furthermore, these results also highlight the need for caution in studies of sexual selection when extrapolating from patterns of female preference obtained under ideal laboratory conditions to conclusions about how those preferences are expressed in the real world.

  14. Multiple hybrid de novo genome assembly of finger millet, an orphan allotetraploid crop.

    Science.gov (United States)

    Hatakeyama, Masaomi; Aluri, Sirisha; Balachadran, Mathi Thumilan; Sivarajan, Sajeevan Radha; Patrignani, Andrea; Grüter, Simon; Poveda, Lucy; Shimizu-Inatsugi, Rie; Baeten, John; Francoijs, Kees-Jan; Nataraja, Karaba N; Reddy, Yellodu A Nanja; Phadnis, Shamprasad; Ravikumar, Ramapura L; Schlapbach, Ralph; Sreeman, Sheshshayee M; Shimizu, Kentaro K

    2017-09-05

    Finger millet (Eleusine coracana (L.) Gaertn) is an important crop for food security because of its tolerance to drought, which is expected to be exacerbated by global climate changes. Nevertheless, it is often classified as an orphan/underutilized crop because of the paucity of scientific attention. Among several small millets, finger millet is considered as an excellent source of essential nutrient elements, such as iron and zinc; hence, it has potential as an alternate coarse cereal. However, high-quality genome sequence data of finger millet are currently not available. One of the major problems encountered in the genome assembly of this species was its polyploidy, which hampers genome assembly compared with a diploid genome. To overcome this problem, we sequenced its genome using diverse technologies with sufficient coverage and assembled it via a novel multiple hybrid assembly workflow that combines next-generation with single-molecule sequencing, followed by whole-genome optical mapping using the Bionano Irys® system. The total number of scaffolds was 1,897 with an N50 length >2.6 Mb and detection of 96% of the universal single-copy orthologs. The majority of the homeologs were assembled separately. This indicates that the proposed workflow is applicable to the assembly of other allotetraploid genomes. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  15. The Complete Chloroplast Genome of Wild Rice (Oryza minuta) and Its Comparison to Related Species.

    Science.gov (United States)

    Asaf, Sajjad; Waqas, Muhammad; Khan, Abdul L; Khan, Muhammad A; Kang, Sang-Mo; Imran, Qari M; Shahzad, Raheem; Bilal, Saqib; Yun, Byung-Wook; Lee, In-Jung

    2017-01-01

    Oryza minuta , a tetraploid wild relative of cultivated rice (family Poaceae), possesses a BBCC genome and contains genes that confer resistance to bacterial blight (BB) and white-backed (WBPH) and brown (BPH) plant hoppers. Based on the importance of this wild species, this study aimed to understand the phylogenetic relationships of O. minuta with other Oryza species through an in-depth analysis of the composition and diversity of the chloroplast (cp) genome. The analysis revealed a cp genome size of 135,094 bp with a typical quadripartite structure and consisting of a pair of inverted repeats separated by small and large single copies, 139 representative genes, and 419 randomly distributed microsatellites. The genomic organization, gene order, GC content and codon usage are similar to those of typical angiosperm cp genomes. Approximately 30 forward, 28 tandem and 20 palindromic repeats were detected in the O . minuta cp genome. Comparison of the complete O. minuta cp genome with another eleven Oryza species showed a high degree of sequence similarity and relatively high divergence of intergenic spacers. Phylogenetic analyses were conducted based on the complete genome sequence, 65 shared genes and matK gene showed same topologies and O. minuta forms a single clade with parental O. punctata . Thus, the complete O . minuta cp genome provides interesting insights and valuable information that can be used to identify related species and reconstruct its phylogeny.

  16. Asymmetric evolution and domestication in allotetraploid cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    Lei Fang

    2017-04-01

    Full Text Available Polyploidy plays a major role in genome evolution, which corresponds to environmental changes over millions of years. The mechanisms of genome evolution, particularly during the process of domestication, are of broad interest in the fields of plant science and crop breeding. Upland cotton is derived from the hybridization and polyploidization of its ancient A and D diploid ancestors. As a result, cotton is a model for polyploid genome evolution and crop domestication. To explore the genomic mysteries of allopolyploid cotton, we investigated asymmetric evolution and domestication in the A and D subgenomes. Interestingly, more structural rearrangements have been characterized in the A subgenome than in the D subgenome. Correspondingly, more transposable elements, a greater number of lost and disrupted genes, and faster evolution have been identified in the A subgenome. In contrast, the centromeric retroelement (RT-domain related sequence of tetraploid cotton derived from the D subgenome progenitor was found to have invaded the A subgenome centromeres after allotetrapolyploid formation. Although there is no genome-wide expression bias between the subgenomes, as with expression-level alterations, gene expression bias of homoeologous gene pairs is widespread and varies from tissue to tissue. Further, there are more positively selected genes for fiber yield and quality in the A subgenome and more for stress tolerance in the D subgenome, indicating asymmetric domestication. This review highlights the asymmetric subgenomic evolution and domestication of allotetraploid cotton, providing valuable genomic resources for cotton research and enhancing our understanding of the basis of many other allopolyploids.

  17. [Determination of five arsenic species in rice by liquid chromatography-inductively coupled plasma-mass spectrometry].

    Science.gov (United States)

    Gong, Jiadi; Cao, Xiaolin; Cao, Zhaoyun; Bian, Yingfang; Yu, Shasha; Chen, Mingxue

    2014-07-01

    A method was developed for the simultaneous determination of arsenic acid [As (V)], arsenious acid [As (III)], arsenobetaine (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in rice by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). The extraction reagent was 0.3 mol/L nitric acid with heat-assistant condition for 1.5 h at 95 degrees C. Then, the five arsenic species were separated by an anion exchange column (Dionex IonPac AS19, 250 mm x 4 mm) and detected by ICP-MS. Four kinds of extracted solutions were compared through the extraction efficiency. The concentration of nitric acid, the temperature and the extraction time were optimized. The recoveries of the five arsenic species spiked in rice at two levels ranged from 89.6% to 99.5% with the relative standard deviations (RSDs, n = 5) of 0.6% - 3.6%. The measured values of the arsenic species in standard rice materials were consistent with their standard values. The linear ranges were 0.05 - 200 microg/L for AsB and DMA, 0.10-400 microg/L for As (III) and MMA, 0.15-600 microg/L for As (V). The limits of detection for the five arsenic species were 0.15-0.45 microg/kg. The results showed that the method is much more precise for the risk assessment of the rice. This method is simple, accurate and durable for the determination of arsenic species in rice.

  18. Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species

    Science.gov (United States)

    Elbeltagy, Adel; Nishioka, Kiyo; Sato, Tadashi; Suzuki, Hisa; Ye, Bin; Hamada, Toru; Isawa, Tsuyoshi; Mitsui, Hisayuki; Minamisawa, Kiwamu

    2001-01-01

    Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum, Ideonella, Enterobacter, and Azospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2 gas incorporation assays. Therefore, we conclude that Herbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis. PMID:11679357

  19. Structural and Functional Diversity of Weed Species in Organic and Conventional Rice Agro-Ecosystems

    Directory of Open Access Journals (Sweden)

    S. Y. Mousawi Toghani

    2016-02-01

    Full Text Available Introduction Diversity reflects the complexity of a system and can maintain its sustainability. Higherdiversity, results in higher inherent complexity of agro-ecosystems and strengthen their processes. It is necessary to realize the spatial distribution and temporal properties of the biodiversity components in agro-ecosystems, for the conservation and optimal utilization. Since weeds as a complementary component of agro-ecosystems and are inseparable, so the study of species, their functional and structural diversity of them can play an important role in weed management and balance in ecological systems. Materials and Methods This study was performed to determine the effects of different management systems on structural, and functional diversity of paddy weeds in Mazandaran province. Three rice fields, ranged from 0.3 to 0.5 ha, were chosen for each management system. Samples were collected from three fields running under each selected management system (organic and conventional. Data (number of weed species and their density were randomly gathered from 9 quadrates (1m×1m per each field in four stages (tillering, stem elongation, grain filling and after harvest. The diversity, evenness, frequency and similarity indices for weeds were determined at genera and species level. Data analysis carried out through T-test and grouping performed via cluster analysis as hierarchy. Results and Discussion All monitored weeds can be classified into four plant family including cereals (Poaceae, sedges (Cyperaceae, plantain (Plantaginaceae and chicory (Asteraceae.Under conventional systems the values of weed diversity indices were higher during tillering and stem elongation compared with organic ones, and were lower during grain filling and after harvest stages. However indices of weed evenness showed contrary tendency. Both Sympson and Shanon-Wiener diversity indices, consist of two clusters in 76% similarity. Evenness indices of Kamargo and Smith

  20. Regulation of reactive oxygen and nitrogen species by salicylic acid in rice plants under salinity stress conditions

    Science.gov (United States)

    Mun, Bong-Gyu; Khan, Abdul Latif; Waqas, Muhammad; Kim, Hyun-Ho; Shahzad, Raheem; Imran, Muhammad

    2018-01-01

    This study investigated the regulatory role of exogenous salicylic acid (SA) in rice and its effects on toxic reactive oxygen and nitrogen species during short-term salinity stress. SA application (0.5 and 1.0 mM) during salinity-induced stress (100 mM NaCl) resulted in significantly longer shoot length and higher chlorophyll and biomass accumulation than with salinity stress alone. NaCl-induced reactive oxygen species production led to increased levels of lipid peroxidation in rice plants, which were significantly reduced following SA application. A similar finding was observed for superoxide dismutase; however, catalase (CAT) and ascorbate peroxidase (APX) were significantly reduced in rice plants treated with SA and NaCl alone and in combination. The relative mRNA expression of OsCATA and OsAPX1 was lower in rice plants during SA stress. Regarding nitrogenous species, S-nitrosothiol (SNO) was significantly reduced initially (one day after treatment [DAT]) but then increased in plants subjected to single or combined stress conditions. Genes related to SNO biosynthesis, S-nitrosoglutathione reductase (GSNOR1), NO synthase-like activity (NOA), and nitrite reductase (NIR) were also assessed. The mRNA expression of GSNOR1 was increased relative to that of the control, whereas OsNOA was expressed at higher levels in plants treated with SA and NaCl alone relative to the control. The mRNA expression of OsNR was decreased in plants subjected to single or combination treatment, except at 2 DAT, compared to the control. In conclusion, the current findings suggest that SA can regulate the generation of NaCl-induced oxygen and nitrogen reactive species in rice plants. PMID:29558477

  1. Analysis of Rhizome Development in Oryza longistaminata, a Wild Rice Species.

    Science.gov (United States)

    Yoshida, Akiko; Terada, Yasuhiko; Toriba, Taiyo; Kose, Katsumi; Ashikari, Motoyuki; Kyozuka, Junko

    2016-10-01

    Vegetative reproduction is a form of asexual propagation in plants. A wide range of plants develop rhizomes, modified stems that grow underground horizontally, as a means of vegetative reproduction. In rhizomatous species, despite their distinct developmental patterns, both rhizomes and aerial shoots derive from axillary buds. Therefore, it is of interest to understand the basis of rhizome initiation and development. Oryza longistaminata, a wild rice species, develops rhizomes. We analyzed bud initiation and growth of O. longistaminata rhizomes using various methods of morphological observation. We show that, unlike aerial shoot buds that contain a few leaves only, rhizome buds initiate several leaves and bend to grow at right angles to the original rhizome. Rhizomes are maintained in the juvenile phase irrespective of the developmental phase of the aerial shoot. Stem elongation and reproductive transition are tightly linked in the aerial shoots, but are uncoupled in the rhizome. Our findings indicate that developmental programs operate independently in the rhizomes and aerial shoots. Temporal modification of the developmental pathways that are common to rhizomes and aerial shoots may be the source of developmental plasticity. Furthermore, the creation of new developmental systems appears to be necessary for rhizome development. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Suberized transport barriers in Arabidopsis, barley and rice roots: From the model plant to crop species.

    Science.gov (United States)

    Kreszies, Tino; Schreiber, Lukas; Ranathunge, Kosala

    2018-02-07

    Water is the most important prerequisite for life and plays a major role during uptake and transport of nutrients. Roots are the plant organs that take up the major part of water, from the surrounding soil. Water uptake is related to the root system architecture, root growth, age and species dependent complex developmental changes in the anatomical structures. The latter is mainly attributed to the deposition of suberized barriers in certain layers of cell walls, such as endo- and exodermis. With respect to water permeability, changes in the suberization of roots are most relevant. Water transport or hydraulic conductivity of roots (Lp r ) can be described by the composite transport model and is known to be very variable between plant species and growth conditions and root developmental states. In this review, we summarize how anatomical structures and apoplastic barriers of roots can diversely affect water transport, comparing the model plant Arabidopsis with crop plants, such as barley and rice. Results comparing the suberin amounts and water transport properties indicate that the common assumption that suberin amount negatively correlates with water and solute transport through roots may not always be true. The composition, microstructure and localization of suberin may also have a great impact on the formation of efficient barriers to water and solutes. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

  3. Population Dynamics Among six Major Groups of the Oryza rufipogon Species Complex, Wild Relative of Cultivated Asian Rice.

    Science.gov (United States)

    Kim, HyunJung; Jung, Janelle; Singh, Namrata; Greenberg, Anthony; Doyle, Jeff J; Tyagi, Wricha; Chung, Jong-Wook; Kimball, Jennifer; Hamilton, Ruaraidh Sackville; McCouch, Susan R

    2016-12-01

    Understanding population structure of the wild progenitor of Asian cultivated rice (O. sativa), the Oryza rufipogon species complex (ORSC), is of interest to plant breeders and contributes to our understanding of rice domestication. A collection of 286 diverse ORSC accessions was evaluated for nuclear variation using genotyping-by-sequencing (113,739 SNPs) and for chloroplast variation using Sanger sequencing (25 polymorphic sites). Six wild subpopulations were identified, with 25 % of accessions classified as admixed. Three of the wild groups were genetically and geographically closely related to the O. sativa subpopulations, indica, aus and japonica, and carried O. sativa introgressions; the other three wild groups were genetically divergent, had unique chloroplast haplotypes, and were located at the geographical extremes of the species range. The genetic subpopulations were significantly correlated (r 2  = 0.562) with traditional species designations, O. rufipogon (perennial) and O. nivara (annual), differentiated based on morphology and life history. A wild diversity panel of 95 purified (inbred) accessions was developed for future genetic studies. Our results suggest that the cultivated aus subpopulation is most closely related to an annual wild relative, japonica to a perennial wild relative, and indica to an admixed population of diverse annual and perennial wild ancestors. Gene flow between ORSC and O. sativa is common in regions where rice is cultivated, threatening the identity and diversity of wild ORSC populations. The three geographically isolated ORSC populations harbor variation rarely seen in cultivated rice and provide a unique window into the genetic composition of ancient rice subpopulations.

  4. Genome-Wide Distribution, Organisation and Functional Characterization of Disease Resistance and Defence Response Genes across Rice Species

    Science.gov (United States)

    Singh, Sangeeta; Chand, Suresh; Singh, N. K.; Sharma, Tilak Raj

    2015-01-01

    The resistance (R) genes and defense response (DR) genes have become very important resources for the development of disease resistant cultivars. In the present investigation, genome-wide identification, expression, phylogenetic and synteny analysis was done for R and DR-genes across three species of rice viz: Oryza sativa ssp indica cv 93-11, Oryza sativa ssp japonica and wild rice species, Oryza brachyantha. We used the in silico approach to identify and map 786 R -genes and 167 DR-genes, 672 R-genes and 142 DR-genes, 251 R-genes and 86 DR-genes in the japonica, indica and O. brachyanth a genomes, respectively. Our analysis showed that 60.5% and 55.6% of the R-genes are tandemly repeated within clusters and distributed over all the rice chromosomes in indica and japonica genomes, respectively. The phylogenetic analysis along with motif distribution shows high degree of conservation of R- and DR-genes in clusters. In silico expression analysis of R-genes and DR-genes showed more than 85% were expressed genes showing corresponding EST matches in the databases. This study gave special emphasis on mechanisms of gene evolution and duplication for R and DR genes across species. Analysis of paralogs across rice species indicated 17% and 4.38% R-genes, 29% and 11.63% DR-genes duplication in indica and Oryza brachyantha, as compared to 20% and 26% duplication of R-genes and DR-genes in japonica respectively. We found that during the course of duplication only 9.5% of R- and DR-genes changed their function and rest of the genes have maintained their identity. Syntenic relationship across three genomes inferred that more orthology is shared between indica and japonica genomes as compared to brachyantha genome. Genome wide identification of R-genes and DR-genes in the rice genome will help in allele mining and functional validation of these genes, and to understand molecular mechanism of disease resistance and their evolution in rice and related species. PMID:25902056

  5. Reactive oxygen species dynamics in roots of salt sensitive and salt tolerant cultivars of rice.

    Science.gov (United States)

    Saini, Shivani; Kaur, Navdeep; Pati, Pratap Kumar

    2018-06-01

    Salinity stress is one of the major constraints for growth and survival of plants that affects rice productivity worldwide. Hence, in the present study, roots of two contrasting salinity sensitive cultivars, IR64 (IR64, salt sensitive) and Luna Suvarna (LS, salt tolerant) were compared with regard to the levels of reactive oxygen species (ROS) to derive clues for their differential salt stress adaptation mechanisms. In our investigation, the tolerant cultivar exhibited longer primary roots, more lateral roots, higher root number leading to increased root biomass, with respect to IR64. It was observed that LS roots maintained higher level of H 2 O 2 in comparison to IR64. The activities of various enzymes involved in enzymatic antioxidant defense mechanism (SOD, CAT, GPX, DHAR and MDHAR) were found to be greater in LS roots. Further, the higher transcript level accumulation of genes encoding ROS generating (RbohA, RbohD and RbohE) and scavenging enzymes (Fe-SOD, Chloroplastic Cu/Zn-SOD, CAT and DHAR) were noticed in the roots of tolerant cultivar, LS. Moreover, the content of other stress markers such as total protein and proline were also elevated in LS roots. While, the expression of proline biosynthesis gene (P5CS) and proline catabolism gene (PDH) was observed to be lower in LS. Copyright © 2018. Published by Elsevier Inc.

  6. Non-introgressive genome chimerisation by malsegregation in autodiploidised allotetraploids during meiosis of Saccharomyces kudriavzevii x Saccharomyces uvarum hybrids.

    Science.gov (United States)

    Karanyicz, Edina; Antunovics, Zsuzsa; Kallai, Z; Sipiczki, M

    2017-06-01

    Saccharomyces strains with chimerical genomes consisting of mosaics of the genomes of different species ("natural hybrids") occur quite frequently among industrial and wine strains. The most widely endorsed hypothesis is that the mosaics are introgressions acquired via hybridisation and repeated backcrosses of the hybrids with one of the parental species. However, the interspecies hybrids are sterile, unable to mate with their parents. Here, we show by analysing synthetic Saccharomyces kudriavzevii x Saccharomyces uvarum hybrids that mosaic (chimeric) genomes can arise without introgressive backcrosses. These species are biologically separated by a double sterility barrier (sterility of allodiploids and F1 sterility of allotetraploids). F1 sterility is due to the diploidisation of the tetraploid meiosis resulting in MAT a /MAT α heterozygosity which suppresses mating in the spores. This barrier can occasionally be broken down by malsegregation of autosyndetically paired chromosomes carrying the MAT loci (loss of MAT heterozygosity). Subsequent malsegregation of additional autosyndetically paired chromosomes and occasional allosyndetic interactions chimerise the hybrid genome. Chromosomes are preferentially lost from the S. kudriavzevii subgenome. The uniparental transmission of the mitochondrial DNA to the hybrids indicates that nucleo-mitochondrial interactions might affect the direction of the genomic changes. We propose the name GARMe (Genome AutoReduction in Meiosis) for this process of genome reduction and chimerisation which involves no introgressive backcrossings. It opens a way to transfer genetic information between species and thus to get one step ahead after hybridisation in the production of yeast strains with beneficial combinations of properties of different species.

  7. Reactive Oxygen Species Generated by NADPH Oxidases Promote Radicle Protrusion and Root Elongation during Rice Seed Germination

    Directory of Open Access Journals (Sweden)

    Wen-Yan Li

    2017-01-01

    Full Text Available Seed germination is a complicated biological process that requires regulation through various enzymatic and non-enzymatic mechanisms. Although it has been recognized that reactive oxygen species (ROS regulate radicle emergence and root elongation in a non-enzymatic manner during dicot seed germination, the role of ROS in monocot seed germination remains unknown. NADPH oxidases (NOXs are the major ROS producers in plants; however, whether and how NOXs regulate rice seed germination through ROS generation remains unclear. Here, we report that diphenyleneiodinium (DPI, a specific NOX inhibitor, potently inhibited embryo and seedling growth—especially that of the radicle and of root elongation—in a dose-dependent manner. Notably, the DPI-mediated inhibition of radicle and root growth could be eliminated by transferring seedlings from DPI to water. Furthermore, ROS production/accumulation during rice seed germination was quantified via histochemistry. Superoxide radicals (O2−, hydrogen peroxide (H2O2 and hydroxyl radicals (•OH accumulated steadily in the coleorhiza, radicle and seedling root of germinating rice seeds. Expression profiles of the nine typical NOX genes were also investigated. According to quantitative PCR, OsNOX5, 7 and 9 were expressed relatively higher. When seeds were incubated in water, OsNOX5 expression progressively increased in the embryo from 12 to 48 h, whereas OsNOX7 and 9 expressions increased from 12 to 24 h and decreased thereafter. As expected, DPI inhibits the expression at predetermined time points for each of these genes. Taken together, these results suggest that ROS produced by NOXs are involved in radicle and root elongation during rice seed germination, and OsNOX5, 7 and 9 could play crucial roles in rice seed germination. These findings will facilitate further studies of the roles of ROS generated by NOXs during seed germination and seedling establishment and also provide valuable information for the

  8. Pythium species from rice roots differ in virulence, host colonization and nutritional profile

    OpenAIRE

    Van Buyten, Evelien; Höfte, Monica

    2013-01-01

    Background: Progressive yield decline in Philippine aerobic rice fields has been recently associated with three closely related Pythium spp., P. arrhenomanes, P. graminicola and P. inflatum. To understand their differential virulence towards rice seedlings, we conducted a comparative survey in which three isolates each of P. arrhenomanes, P. graminicola and P. inflatum were selected to investigate host colonization, host responses and carbon utilization profiles using histopathological analys...

  9. An injury equivalency system for establishing a common economic threshold for three species of rice planthoppers (Hemiptera: Delphacidae) in Taiwan.

    Science.gov (United States)

    Huang, Shou-Horng; Chen, Ching-Huan; Chen, Chiou-Nan; Wu, Wen-Jer

    2013-04-01

    The economic threshold (ET) for multiple pest species that share the same injury type on host plants (feeding guild) has been proposed for decision-making in integrated management framework of many defoliating insect pests. However, only a few consider agricultural pests with sucking mouthparts. This study presents the first injury equivalency system for the feeding guild made up of three rice (Oryza sativa L.) planthopper (Hemiptera: Delphacidae) species--Nilaparvata lugens (Stål), Sogatella furcifera (Harváth), and Laodelphax striatellus (Fallén)--by using relative amount of honeydew excretion of each species. The intraspecific injury equivalent coefficient was determined; this coefficient provides an exchange rate for different developmental stages in a species. N. lugens was chosen as the standard species to obtain interspecific injury equivalents for other individuals in the guild, allowing estimates of total guild injury feasible. For extension purposes, the injury equivalency was simplified by pooling all nymphs and adults in the guild to mitigate the potential confusion resulting from uncertainty of instars or wing form. A matrix of ETs established on previous studies and incorporating changes of management cost and rice price was used and served as a control decision guide for the guild samples. The validity of the proposed injury equivalency system was tested using several field data sets, and the results are generally promising and meaningfully elevate the accuracy of estimating combined injury and damage to rice, suggesting that the proposed system is a better integrated pest management decision-making system compared with conventional practices.

  10. The ultrastructure of pollen grain surface in allotetraploid petunia (Petunia hybrida hort. superbissima as revealed by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    S. Muszyński

    2015-01-01

    Full Text Available The ultrastructure of pollen grain surface in allotetraploid petunias was analyzed by scanning electron microscopy. The pollen grain wall is developed into characteristic pattern of convulations.

  11. Immediate Genetic and Epigenetic Changes in F1 Hybrids Parented by Species with Divergent Genomes in the Rice Genus (Oryza.

    Directory of Open Access Journals (Sweden)

    Ying Wu

    Full Text Available Inter-specific hybridization occurs frequently in higher plants, and represents a driving force of evolution and speciation. Inter-specific hybridization often induces genetic and epigenetic instabilities in the resultant homoploid hybrids or allopolyploids, a phenomenon known as genome shock. Although genetic and epigenetic consequences of hybridizations between rice subspecies (e.g., japonica and indica and closely related species sharing the same AA genome have been extensively investigated, those of inter-specific hybridizations between more remote species with different genomes in the rice genus, Oryza, remain largely unknown.We investigated the immediate chromosomal and molecular genetic/epigenetic instability of three triploid F1 hybrids produced by inter-specific crossing between species with divergent genomes of Oryza by genomic in situ hybridization (GISH and molecular marker analysis. Transcriptional and transpositional activity of several transposable elements (TEs and methylation stability of their flanking regions were also assessed. We made the following principle findings: (i all three triploid hybrids are stable in both chromosome number and gross structure; (ii stochastic changes in both DNA sequence and methylation occurred in individual plants of all three triploid hybrids, but in general methylation changes occurred at lower frequencies than genetic changes; (iii alteration in DNA methylation occurred to a greater extent in genomic loci flanking potentially active TEs than in randomly sampled loci; (iv transcriptional activation of several TEs commonly occurred in all three hybrids but transpositional events were detected in a genetic context-dependent manner.Artificially constructed inter-specific hybrids of remotely related species with divergent genomes in genus Oryza are chromosomally stable but show immediate and highly stochastic genetic and epigenetic instabilities at the molecular level. These novel hybrids might

  12. Secondary Metabolite Profiles and Mating Populations of Fusarium species in Section Liseola Associated with Bakanae Disease of Rice

    Directory of Open Access Journals (Sweden)

    Nur Ain Izzati, M. Z.

    2008-01-01

    Full Text Available A total of 25 strains of Fusarium species that belong to F. fujikuroi (a pathogen of bakanae disease, F. proliferatum, F. sacchari, F. subglutinans and F. verticillioides were isolated from rice plants showing typical bakanae symptoms in Malaysia and Indonesia and screened for their secondary metabolites. The objectives of the studies were to determine the physiological variability based on production of moniliformin (MON, fumonisin (FB1, gibberellic acid (GA3 and fusaric acid (FA as well as to ascertain the mating populations (MPs within the Gibberella fujikuroi species complex based on their ability to produce perithecia and viable ascospores. Production of GA3 could be used to separate F. fujikuroi that belongs to MP-C from other species. In crosses with seven standard testers of MPs, 76% of strains could be assigned to at least one of the G. fujikuroi species complex namely MP-A (G. moniliformis, MP-B (G. sacchari, MP-C (G. fujikuroi and MP-D (G. intermedia. Single strain (M3237P that was assigned as MP-C, and has also been identified morphologically as F. fujikuroi was also crossed-fertile with MP-D tester. The secondary metabolites profiles and the presence of MP-A, MP-B, MP-C and MP-D strains on samples of bakanae-infected rice plants are new records in Malaysia.

  13. Toxicity of essential oils from leaves of Piperaceae species in rice stalk stink bug eggs, Tibraca limbativentris (Hemiptera: Pentatomidae

    Directory of Open Access Journals (Sweden)

    Diones Krinski

    Full Text Available ABSTRACT Tibraca limbativentris to is an important rice pest and occurs in all rice-growing regions of Latin America. The control this insect is accomplished with synthetic chemical insecticides, however, new approaches are needed to reduce risks to the environment, to the natural enemies and also to avoid the onset of insecticides resistance. This study was designed to assess the toxicity of essential oils (EOs from leaves of Piper aduncum, P. gaudichaudianum, P. malacophyllum, P. marginatum and P. tuberculatum (Piperaceae on rice stalk stink bug eggs, T. limbativentris. Essential oils were extracted with steam distillation and dilutions were made for bioassays at concentrations of 0.25; 0.5; 1.0; 2.0 and 4.0%. Essential oils from all species of Piperaceae displayed ovicidal activity. The LC50 values indicated that both younger and older eggs were susceptible to these oils. Ovicidal activity is related to the potential toxicity of several compounds, especially dilapiolle, myristicin, cubebene, α-guaiene, longifolene, prezizane, spathulenol, sabinene and δ-2-carene. Thus, EOs tested showed promising results for use as biorational botanical insecticides.

  14. Ultrastructure of Oryza glumaepatula , a wild rice species endemic of tropical America

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    Ethel Sánchez

    2005-06-01

    Full Text Available Oryza glumaepatula is a perennial wild rice species,endemic to tropical America, previously known as the Latin American race of Oryza rufipogon .In Costa Rica, it is found in the northern region of the country, mainly in the wetland of the Medio Queso River, Los Chiles, Alajuela. It is diploid, of AA type genome and because of its genetic relatedness to cultivated rice it is included in the O.sativa complex. We describe the ultrastructure of leaf blade, spikelet, ligule and auricles. Special emphasis is given to those traits of major taxonomic value for O.glumaepatula and to those characters that distinguish this species from O. rufipogon and O. sativa . O. glumaepatula has a leaf blade covered with tombstone-shaped, oblong and spheroid epicuticular wax papillae. It has diamond-shaped stomata surrounded by spherical papillae, rows of zipper-like silica cells, bulky prickle trichomes of ca .40 mu m in length and small hirsute trichomes of ca. 32 mu m in length.The central vein is covered with large,globular papillae of ca. 146 mu m in length,a characteristic that distinguishes this species from O.rufipogon and O.sativa. The border of the leaf blade exhibits a row of even-sized bulky prickle trichomes of ca .42.5 mu m in length.Auricles have attenuated trichomes of ca .5.5 mm in length on the edges and small bicellular trichomes of 120 mu m in length on the surface.The ligule has a large number of short attenuated trichomes on its surface of 100 mu m in length.These latter two traits have important taxonomic value since they were found in O.glumaepatula but not found in O.sativa or in O.rufipogon . The spikelet has the typical morphology of the Oryza genus. Fertile lemmas have abundant spines, a trait shared with O.rufipogon but not with O.sativa. The sterile lemmas are wing-shaped with serrated borders,a characteristic that distinguishes this species from O. rufipogon and O.sativa. All the ultrastructure characters observed in O.glumaepatula from

  15. Photosynthetic /sup 14/CO/sub 2/ fixation in the leaves of rice and some other species

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, R; Samejima, M; Murata, Y [Tokyo Univ. (Japan). Faculty of Agriculture

    1977-03-01

    The activity of CO/sub 2/-fixing enzymes and the initial products of photosynthetic /sup 14/CO/sub 2/ fixation in two rice varieties, the one japonica and the other indica, were examined, comparing with those in several C/sub 3/ and C/sub 4/ crop species. Corn and barnyard grass as C/sub 4/ plants and barley and wheat as C/sub 3/ plants were used as comparison materials. The plants were cultured at 25 deg. C in daytime and 20 deg. C in night under natural light in a phytotron. After about a month from sowing, the fully expanded leaf blades were subjected to the experiments. The fresh leaf blades of one gram were homogenized in 5 ml of 50 mM Tris-H/sub 2/SO/sub 4/ buffer (pH 7.7) containing 4 mM EDTA, 10 mM dithiothreitol and 50 mg of polyamide powder. After filtration, the supernatant was used as the crude enzyme extract for assaying the activity of RuDP carboxylase and PEP carboxylase. The experiments revealed that (1) in C/sub 3/ plants, the RuDP carboxylase activity was higher, and the PEP carboxylase activity was lower than those in C/sub 4/ plants; (2) the initial products of photosynthetic /sup 14/CO/sub 2/ fixation in the japonica rice variety were mainly PGA and other sugar phosphates as in barley, whereas in corn, they were malic and aspartic acids; (3) the /sup 14/C incorporation into glycine and serine was high in the japonica rice and barley, whereas low in corn. From these results, rice could be regarded as C/sub 3/ plant.

  16. Morphological and Molecular Data Reveal Three Distinct Populations of Indian Wild Rice Oryza rufipogon Griff. Species Complex.

    Science.gov (United States)

    Singh, Balwant; Singh, Nisha; Mishra, Shefali; Tripathi, Kabita; Singh, Bikram P; Rai, Vandna; Singh, Ashok K; Singh, Nagendra K

    2018-01-01

    Wild relatives of crops possess adaptive mutations for agronomically important traits, which could play significant role in crop improvement for sustainable agriculture. However, global climate change and human activities pose serious threats to the natural habitats leading to erosion of genetic diversity of wild rice populations. The purpose of this study was to explore and characterize India's huge untapped wild rice diversity in Oryza rufipogon Griff. species complex from a wide range of ecological niches. We made strategic expeditions around diversity hot spots in 64 districts of nine different agro-climatic zones of the country and collected 418 wild rice accessions. Significant variation was observed among the accessions for 46 morphological descriptors, allowing classification into O. nivara, O. rufipogon , and O. sativa f. spontanea morpho-taxonomic groups. Genome-specific pSINE1 markers confirmed all the accessions having AA genome, which were further classified using ecotype-specific pSINE1 markers into annual, perennial, intermediate, and an unknown type. Principal component analysis revealed continuous variation for the morphological traits in each ecotype group. Genetic diversity analysis based on multi-allelic SSR markers clustered these accessions into three major groups and analysis of molecular variance for nine agro-climatic zones showed that 68% of the genetic variation was inherent amongst individuals while only 11% of the variation separated the zones, though there was significant correlation between genetic and spatial distances of the accessions. Model based population structure analysis using genome wide bi-allelic SNP markers revealed three sub-populations designated 'Pro-Indica,' 'Pro-Aus,' and 'Mid-Gangetic,' which showed poor correspondence with the morpho - taxonomic classification or pSINE1 ecotypes. There was Pan-India distribution of the 'Pro-Indica' and 'Pro-Aus' sub-populations across agro-climatic zones, indicating a more

  17. Morphological and Molecular Data Reveal Three Distinct Populations of Indian Wild Rice Oryza rufipogon Griff. Species Complex

    Science.gov (United States)

    Singh, Balwant; Singh, Nisha; Mishra, Shefali; Tripathi, Kabita; Singh, Bikram P.; Rai, Vandna; Singh, Ashok K.; Singh, Nagendra K.

    2018-01-01

    Wild relatives of crops possess adaptive mutations for agronomically important traits, which could play significant role in crop improvement for sustainable agriculture. However, global climate change and human activities pose serious threats to the natural habitats leading to erosion of genetic diversity of wild rice populations. The purpose of this study was to explore and characterize India’s huge untapped wild rice diversity in Oryza rufipogon Griff. species complex from a wide range of ecological niches. We made strategic expeditions around diversity hot spots in 64 districts of nine different agro-climatic zones of the country and collected 418 wild rice accessions. Significant variation was observed among the accessions for 46 morphological descriptors, allowing classification into O. nivara, O. rufipogon, and O. sativa f. spontanea morpho-taxonomic groups. Genome-specific pSINE1 markers confirmed all the accessions having AA genome, which were further classified using ecotype-specific pSINE1 markers into annual, perennial, intermediate, and an unknown type. Principal component analysis revealed continuous variation for the morphological traits in each ecotype group. Genetic diversity analysis based on multi-allelic SSR markers clustered these accessions into three major groups and analysis of molecular variance for nine agro-climatic zones showed that 68% of the genetic variation was inherent amongst individuals while only 11% of the variation separated the zones, though there was significant correlation between genetic and spatial distances of the accessions. Model based population structure analysis using genome wide bi-allelic SNP markers revealed three sub-populations designated ‘Pro-Indica,’ ‘Pro-Aus,’ and ‘Mid-Gangetic,’ which showed poor correspondence with the morpho-taxonomic classification or pSINE1 ecotypes. There was Pan-India distribution of the ‘Pro-Indica’ and ‘Pro-Aus’ sub-populations across agro-climatic zones

  18. Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding

    Directory of Open Access Journals (Sweden)

    Williams Warren M

    2012-04-01

    Full Text Available Abstract Background White clover (Trifolium repens is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. Results T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Conclusions Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens hybridized with a diploid coastal species (T. occidentale to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime, along with allotetraploidy, has led to a transgressive hybrid with a

  19. Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding.

    Science.gov (United States)

    Williams, Warren M; Ellison, Nicholas W; Ansari, Helal A; Verry, Isabelle M; Hussain, S Wajid

    2012-04-24

    White clover (Trifolium repens) is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH) and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens) hybridized with a diploid coastal species (T. occidentale) to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime), along with allotetraploidy, has led to a transgressive hybrid with a broad adaptive range.

  20. Interaction between Pyricularia oryzae, four Helminthosporium species and Curvularia lunata in rice leaves

    Directory of Open Access Journals (Sweden)

    M. Bahous

    2003-08-01

    Full Text Available The interaction between six fungal parasites of rice: Pyricularia oryzae, Helminthosporium oryzae, H. sativum, H. spiciferum, H. australiensis and Curvularia lunata was studied quantitatively by a modified plant ecology technique known as the de Wit replacement series. Each fungus was inoculated alone or in combination with one of the other five fungi in various proportions into rice plants under experimental conditions. Leaves developing lesions were harvested and incubated in a moist chamber. The yield of each fungus was its conidial production on the rice leaves. The artificial inoculations indicated that interactions between the pathogens in the mixture could be beneficial, antagonistic, or null. Interspecific interaction (i.e. antagonism occurred in the majority of paired combinations (H. oryzae + P. oryzae; H. sativum + H. spiciferum, H. australiensis, C. lunata or P. oryzae; H. australiensis + H. spiciferum, C. lunata or P. oryzae; and P. oryzae + C. lunata. The relative yield total (RYT lines were significantly lower than the expected value, which is 1. The RYT lines were concave upward, revealing a beneficial effect of one or both pathogens on the other, when H. oryzae was in mixture with H. sativum or H. spiciferum. A null effect between fungi occurred in four combinations (H. oryzae + H. australiensis or C. lunata; H. spiciferum + C. lunata; and P. oryzae + H. spiciferum showing that with these combinations inter- and intraspecific competitions were equal in intensity. Thus, the de Wit replacement series technique indicated that it was possible to quantify the interaction between all the pathogenic fungi tested.

  1. Rice as commodity and anti-commodity

    NARCIS (Netherlands)

    Richards, P.

    2016-01-01

    On the Upper West Africa coast rice belongs to two species — African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.). African rice was domesticated in the region, perhaps three millennia ago, from a presumed wild ancestor, O. barthii. Asian rice was introduced via trans-Saharan

  2. Determination of arsenic species in rice samples using CPE and ETAAS.

    Science.gov (United States)

    Costa, Bruno Elias Dos Santos; Coelho, Nívia Maria Melo; Coelho, Luciana Melo

    2015-07-01

    A highly sensitive and selective procedure for the determination of arsenate and total arsenic in food by electrothermal atomic absorption spectrometry after cloud point extraction (ETAAS/CPE) was developed. The procedure is based on the formation of a complex of As(V) ions with molybdate in the presence of 50.0 mmol L(-1) sulfuric acid. The complex was extracted into the surfactant-rich phase of 0.06% (w/v) Triton X-114. The variables affecting the complex formation, extraction and phase separation were optimized using factorial designs. Under the optimal conditions, the calibration graph was linear in the range of 0.05-10.0 μg L(-1). The detection and quantification limits were 10 and 33 ng L(-1), respectively and the corresponding value for the relative standard deviation for 10 replicates was below 5%. Recovery values of between 90.8% and 113.1% were obtained for spiked samples. The accuracy of the method was evaluated by comparison with the results obtained for the analysis of a rice flour sample (certified material IRMM-804) and no significant difference at the 95% confidence level was observed. The method was successfully applied to the determination of As(V) and total arsenic in rice samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Sites of infection by pythium species in rice seedlings and effects of plant age and water depth on disease development.

    Science.gov (United States)

    Chun, S C; Schneider, R W

    1998-12-01

    ABSTRACT Seedling disease, caused primarily by several species of Pythium, is one of the major constraints to water-seeded rice production in Louisiana. The disease, also known as water-mold disease, seed rot, and seedling damping-off, causes stand reductions and growth abnormalities. In severe cases, fields must be replanted, which may result in delayed harvests and reduced yields. To develop more effective disease management tactics including biological control, this study was conducted primarily to determine sites of infection in seeds and seedlings; effect of plant age on susceptibility to P. arrhenomanes, P. myriotylum, and P. dissotocum; and minimum exposure times required for infection and seedling death. In addition, the effect of water depth on seedling disease was investigated. Infection rates of seed embryos were significantly higher than those of endosperms for all three Pythium spp. The development of roots from dry-seeded seedlings was significantly reduced by P. arrhenomanes and P. myriotylum at 5 days after planting compared with that of roots from noninoculated controls. Susceptibility of rice to all three species was sharply reduced within 2 to 6 days after planting, and seedlings were completely resistant at 8 days after planting. There was a steep reduction in emergence through the flood water, relative to the noninoculated control, following 2 to 3 days of exposure to inoculum of P. arrhenomanes and P. myriotylum. In contrast, P. dissotocum was much less virulent and required longer exposure times to cause irreversible seedling damage. Disease incidence was higher when seeds were planted into deeper water, implying that seedlings become resistant after they emerge through the flood water. These results suggest that disease control tactics including flood water management need to be employed for a very short period of time after planting. Also, given that the embryo is the primary site of infection and it is susceptible for only a few days, the

  4. Identification and Evaluation of Single-Nucleotide Polymorphisms in Allotetraploid Peanut (Arachis hypogaea L.) Based on Amplicon Sequencing Combined with High Resolution Melting (HRM) Analysis.

    Science.gov (United States)

    Hong, Yanbin; Pandey, Manish K; Liu, Ying; Chen, Xiaoping; Liu, Hong; Varshney, Rajeev K; Liang, Xuanqiang; Huang, Shangzhi

    2015-01-01

    The cultivated peanut (Arachis hypogaea L.) is an allotetraploid (AABB) species derived from the A-genome (Arachis duranensis) and B-genome (Arachis ipaensis) progenitors. Presence of two versions of a DNA sequence based on the two progenitor genomes poses a serious technical and analytical problem during single nucleotide polymorphism (SNP) marker identification and analysis. In this context, we have analyzed 200 amplicons derived from expressed sequence tags (ESTs) and genome survey sequences (GSS) to identify SNPs in a panel of genotypes consisting of 12 cultivated peanut varieties and two diploid progenitors representing the ancestral genomes. A total of 18 EST-SNPs and 44 genomic-SNPs were identified in 12 peanut varieties by aligning the sequence of A. hypogaea with diploid progenitors. The average frequency of sequence polymorphism was higher for genomic-SNPs than the EST-SNPs with one genomic-SNP every 1011 bp as compared to one EST-SNP every 2557 bp. In order to estimate the potential and further applicability of these identified SNPs, 96 peanut varieties were genotyped using high resolution melting (HRM) method. Polymorphism information content (PIC) values for EST-SNPs ranged between 0.021 and 0.413 with a mean of 0.172 in the set of peanut varieties, while genomic-SNPs ranged between 0.080 and 0.478 with a mean of 0.249. Total 33 SNPs were used for polymorphism detection among the parents and 10 selected lines from mapping population Y13Zh (Zhenzhuhei × Yueyou13). Of the total 33 SNPs, nine SNPs showed polymorphism in the mapping population Y13Zh, and seven SNPs were successfully mapped into five linkage groups. Our results showed that SNPs can be identified in allotetraploid peanut with high accuracy through amplicon sequencing and HRM assay. The identified SNPs were very informative and can be used for different genetic and breeding applications in peanut.

  5. HYR1-mediated detoxification of reactive oxygen species is required for full virulence in the rice blast fungus.

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    Kun Huang

    2011-04-01

    Full Text Available During plant-pathogen interactions, the plant may mount several types of defense responses to either block the pathogen completely or ameliorate the amount of disease. Such responses include release of reactive oxygen species (ROS to attack the pathogen, as well as formation of cell wall appositions (CWAs to physically block pathogen penetration. A successful pathogen will likely have its own ROS detoxification mechanisms to cope with this inhospitable environment. Here, we report one such candidate mechanism in the rice blast fungus, Magnaporthe oryzae, governed by a gene we refer to as MoHYR1. This gene (MGG_07460 encodes a glutathione peroxidase (GSHPx domain, and its homologue in yeast was reported to specifically detoxify phospholipid peroxides. To characterize this gene in M. oryzae, we generated a deletion mutantΔhyr1 which showed growth inhibition with increased amounts of hydrogen peroxide (H₂O₂. Moreover, we observed that the fungal mutants had a decreased ability to tolerate ROS generated by a susceptible plant, including ROS found associated with CWAs. Ultimately, this resulted in significantly smaller lesion sizes on both barley and rice. In order to determine how this gene interacts with other (ROS scavenging-related genes in M. oryzae, we compared expression levels of ten genes in mutant versus wild type with and without H₂O₂. Our results indicated that the HYR1 gene was important for allowing the fungus to tolerate H₂O₂ in vitro and in planta and that this ability was directly related to fungal virulence.

  6. DNA methylation analysis of allotetraploid hybrids of red crucian carp (Carassius auratus red var. and common carp (Cyprinus carpio L..

    Directory of Open Access Journals (Sweden)

    Jun Xiao

    Full Text Available Hybridization and polyploidization may lead to divergence in adaptation and boost speciation in angiosperms and some lower animals. Epigenetic change plays a significant role in the formation and adaptation of polyploidy. Studies of the effects of methylation on genomic recombination and gene expression in allopolyploid plants have achieved good progress. However, relevant advances in polyploid animals have been relatively slower. In the present study, we used the bisexual, fertile, genetically stable allotetraploid generated by hybridization of Carassius auratus red var. and Cyprinus carpio L. to investigate cytosine methylation level using methylation-sensitive amplification polymorphism (MSAP analysis. We observed 38.31% of the methylation changes in the allotetraploid compared with the parents at 355 randomly selected CCGG sites. In terms of methylation status, these results indicate that the level of methylation modification in the allotetraploid may have increased relative to that in the parents. We also found that the major methylation changes were hypermethylation on some genomic fragments and genes related to metabolism or cell cycle regulation. These results provide circumstantial evidence that DNA methylation might be related to the gene expression and phenotype variation in allotetraploid hybrids. Our study partly fulfils the need for epigenetic research in polyploid animals, and provides evidence for the epigenetic regulation of allopolyploids.

  7. Simultaneous determination of arsenic and mercury species in rice by ion-pairing reversed phase chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Fang, Yong; Pan, Yushi; Li, Peng; Xue, Mei; Pei, Fei; Yang, Wenjian; Ma, Ning; Hu, Qiuhui

    2016-12-15

    An analytical method using reversed phase chromatography-inductively coupled plasma mass spectrometry for arsenic and mercury speciation analysis was described. The effect of ion-pairing reagent on simultaneous separation of four arsenic (arsenite, arsenate, monomethlyarsonate and dimethylarsinate) and three mercury species (inorganic mercury (Hg(II)), methylmecury and ethylmercury) was investigated. Parameters including concentrations and pH of the mobile phase were optimized. The separation and re-equilibration time was attained within 20min. Meanwhile, a sequential extraction method for arsenic and mercury in rice was tested. Subsequently, 1% HNO3 microwave-assisted extraction was chosen. Calibration curves based on peak area measurements were linear with correlation coefficient greater than 0.9958 for each species in the range studied. The detection limits of the species were in the range of 0.84-2.41μg/L for arsenic and 0.01-0.04μg/L for mercury, respectively. The proposed method was then successfully applied for the simultaneous determination of arsenic and mercury species in rice flour standard material and two kinds of rice from local markets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The new species Enterobacter oryziphilus sp nov and Enterobacter oryzendophyticus sp nov are key inhabitants of the endosphere of rice

    NARCIS (Netherlands)

    Hardoim, Pablo Rodrigo; Nazir, Rashid; Sessitsch, Angela; Elhottova, Dana; Korenblum, Elisa; van Overbeek, Leonard Simon; van Elsas, Jan Dirk

    2013-01-01

    Background: Six independent Gram-negative, facultatively anaerobic, non-spore-forming, nitrogen-fixing rod-shaped isolates were obtained from the root endosphere of rice grown at the International Rice Research Institute (IRRI) and investigated in a polyphasic taxonomic study. Results: The strains

  9. The new species Enterobacter oryzaphilus sp. nov. and Enterobacter oryzaendophyticus sp. nov. are key inhabitants of the endosphere of rice.

    NARCIS (Netherlands)

    Hardoim, P.R.; Nazir, R.; Sessitsch, A.; Elhottova, D.; Korenblum, E.; Overbeek, van L.S.; Elsas, J.D.

    2013-01-01

    BACKGROUND: Six independent Gram-negative, facultatively anaerobic, non-spore-forming, nitrogen-fixing rod-shaped isolates were obtained from the root endosphere of rice grown at the International Rice Research Institute (IRRI) and investigated in a polyphasic taxonomic study.
    RESULTS: The

  10. Insights into the Musa genome: Syntenic relationships to rice and between Musa species

    NARCIS (Netherlands)

    Piffanelli, P.; Ciampi, A.Y.; Silva, F.R.; Santos, C.R.; Dhont, A.; Vilarinhos, A.; Pappas, G.; Souza, M.T.; Milller, R.N.G.

    2008-01-01

    Musa species (Zingiberaceae, Zingiberales) including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning Musa genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no

  11. A novel blast resistance gene, Pi54rh cloned from wild species of rice, Oryza rhizomatis confers broad spectrum resistance to Magnaporthe oryzae.

    Science.gov (United States)

    Das, Alok; Soubam, D; Singh, P K; Thakur, S; Singh, N K; Sharma, T R

    2012-06-01

    The dominant rice blast resistance gene, Pi54 confers resistance to Magnaporthe oryzae in different parts of India. In our effort to identify more effective forms of this gene, we isolated an orthologue of Pi54 named as Pi54rh from the blast-resistant wild species of rice, Oryza rhizomatis, using allele mining approach and validated by complementation. The Pi54rh belongs to CC-NBS-LRR family of disease resistance genes with a unique Zinc finger (C(3)H type) domain. The 1,447 bp Pi54rh transcript comprises of 101 bp 5'-UTR, 1,083 bp coding region and 263 bp 3'-UTR, driven by pathogen inducible promoter. We showed the extracellular localization of Pi54rh protein and the presence of glycosylation, myristoylation and phosphorylation sites which implicates its role in signal transduction process. This is in contrast to other blast resistance genes that are predicted to be intracellular NBS-LRR-type resistance proteins. The Pi54rh was found to express constitutively at basal level in the leaves, but upregulates 3.8-fold at 96 h post-inoculation with the pathogen. Functional validation of cloned Pi54rh gene using complementation test showed high degree of resistance to seven isolates of M. oryzae collected from different geographical locations of India. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54rh cloned from wild species of rice provides broad spectrum resistance to M. oryzae hence can be used in rice improvement breeding programme.

  12. Sequencing of allotetraploid cotton (Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement.

    Science.gov (United States)

    Zhang, Tianzhen; Hu, Yan; Jiang, Wenkai; Fang, Lei; Guan, Xueying; Chen, Jiedan; Zhang, Jinbo; Saski, Christopher A; Scheffler, Brian E; Stelly, David M; Hulse-Kemp, Amanda M; Wan, Qun; Liu, Bingliang; Liu, Chunxiao; Wang, Sen; Pan, Mengqiao; Wang, Yangkun; Wang, Dawei; Ye, Wenxue; Chang, Lijing; Zhang, Wenpan; Song, Qingxin; Kirkbride, Ryan C; Chen, Xiaoya; Dennis, Elizabeth; Llewellyn, Danny J; Peterson, Daniel G; Thaxton, Peggy; Jones, Don C; Wang, Qiong; Xu, Xiaoyang; Zhang, Hua; Wu, Huaitong; Zhou, Lei; Mei, Gaofu; Chen, Shuqi; Tian, Yue; Xiang, Dan; Li, Xinghe; Ding, Jian; Zuo, Qiyang; Tao, Linna; Liu, Yunchao; Li, Ji; Lin, Yu; Hui, Yuanyuan; Cao, Zhisheng; Cai, Caiping; Zhu, Xiefei; Jiang, Zhi; Zhou, Baoliang; Guo, Wangzhen; Li, Ruiqiang; Chen, Z Jeffrey

    2015-05-01

    Upland cotton is a model for polyploid crop domestication and transgenic improvement. Here we sequenced the allotetraploid Gossypium hirsutum L. acc. TM-1 genome by integrating whole-genome shotgun reads, bacterial artificial chromosome (BAC)-end sequences and genotype-by-sequencing genetic maps. We assembled and annotated 32,032 A-subgenome genes and 34,402 D-subgenome genes. Structural rearrangements, gene loss, disrupted genes and sequence divergence were more common in the A subgenome than in the D subgenome, suggesting asymmetric evolution. However, no genome-wide expression dominance was found between the subgenomes. Genomic signatures of selection and domestication are associated with positively selected genes (PSGs) for fiber improvement in the A subgenome and for stress tolerance in the D subgenome. This draft genome sequence provides a resource for engineering superior cotton lines.

  13. Toward allotetraploid cotton genome assembly: integration of a high-density molecular genetic linkage map with DNA sequence information

    Science.gov (United States)

    2012-01-01

    Background Cotton is the world’s most important natural textile fiber and a significant oilseed crop. Decoding cotton genomes will provide the ultimate reference and resource for research and utilization of the species. Integration of high-density genetic maps with genomic sequence information will largely accelerate the process of whole-genome assembly in cotton. Results In this paper, we update a high-density interspecific genetic linkage map of allotetraploid cultivated cotton. An additional 1,167 marker loci have been added to our previously published map of 2,247 loci. Three new marker types, InDel (insertion-deletion) and SNP (single nucleotide polymorphism) developed from gene information, and REMAP (retrotransposon-microsatellite amplified polymorphism), were used to increase map density. The updated map consists of 3,414 loci in 26 linkage groups covering 3,667.62 cM with an average inter-locus distance of 1.08 cM. Furthermore, genome-wide sequence analysis was finished using 3,324 informative sequence-based markers and publicly-available Gossypium DNA sequence information. A total of 413,113 EST and 195 BAC sequences were physically anchored and clustered by 3,324 sequence-based markers. Of these, 14,243 ESTs and 188 BACs from different species of Gossypium were clustered and specifically anchored to the high-density genetic map. A total of 2,748 candidate unigenes from 2,111 ESTs clusters and 63 BACs were mined for functional annotation and classification. The 337 ESTs/genes related to fiber quality traits were integrated with 132 previously reported cotton fiber quality quantitative trait loci, which demonstrated the important roles in fiber quality of these genes. Higher-level sequence conservation between different cotton species and between the A- and D-subgenomes in tetraploid cotton was found, indicating a common evolutionary origin for orthologous and paralogous loci in Gossypium. Conclusion This study will serve as a valuable genomic resource

  14. CCQM-K108.2014: determination of arsenic species and total arsenic in brown rice flour

    Science.gov (United States)

    Inagaki, K.; Narukawa, T.; Hioki, A.; Miyashita, S.; Long, S. E.; Ellisor, M. B.; Peng, S. L.; Dewi, F.; Shin, R.; Kapp, T.; Wai-hong, F.; Hei-shing, C.; Chao, W.; Kaewkhomdee, N.; Taebunpakul, S.; Thiengmanee, U.; Yafa, C.

    2017-01-01

    The key comparison CCQM-K108.2014 was organised by the Inorganic Analysis Working Group (IAWG) of CCQM to test the abilities of the national metrology institutes (NMIs) or the designated institutes (DIs) to measure the mass fractions of inorganic arsenic (i-As, sum of the amount of arsenite [As(III)] and arsenate [As(V)]), dimethylarsinic acid (DMAA), and total arsenic (total As) in brown rice flour. This was the follow-up comparison for the CCQM-K108 & CCQM-P147 (Cd, As, inorganic arsenic, and DMAA in brown rice flour). For total As, no strong outliers among the reported values were observed, and the distribution of the results was narrow, within 3% around the median. For i-As and DMAA, the distributions of the results were slightly wider than that for total arsenic, but no strong outliers among the reported values of i-As and DMAA were observed. Two potentially bias sources, an extraction efficiency of As species (the ratio of the sum of i-As and DMAA to total As) and the quality of primary standard of DMAA, were discussed. The extraction efficiency was estimated as the ratio of the sum of i-As and DMAA to total As. In the previous comparison (CCQM-K108 & CCQM-P147), the extraction efficiency was one of the largest bias sources for i-As and DMAA. However, in this study, all the extraction efficiencies estimated from the reported values were close to 100 %. Regarding the quality of the primary standard solutions, no significant difference was observed among the primary standard solution used by the participants. These results suggest the two potential bias sources mentioned above would not have been majors in this study, and then the technical issues in the previous comparison had been overcome. Accounting for relative expanded uncertainty, a comparability of measurement was successfully demonstrated by the participating NMIs and DIs for the measurement of total As at the level of less than 0.7 mg/kg, i-As at the level of less than 0.6 mg/kg, and DMAA at the level

  15. Reactive oxygen species induced by heat stress during grain filling of rice (Oryza sativa L.) are involved in occurrence of grain chalkiness.

    Science.gov (United States)

    Suriyasak, Chetphilin; Harano, Keisuke; Tanamachi, Koichiro; Matsuo, Kazuhiro; Tamada, Aina; Iwaya-Inoue, Mari; Ishibashi, Yushi

    2017-09-01

    Heat stress during grain filling increases rice grain chalkiness due to increased activity of α-amylase, which hydrolyzes starch. In rice and barley seeds, reactive oxygen species (ROS) produced after imbibition induce α-amylase activity via regulation of gibberellin (GA) and abscisic acid (ABA) levels during seed germination. Here, we examined whether ROS is involved in induction of grain chalkiness by α-amylase in developing rice grains under heat stress. To elucidate the role of ROS in grain chalkiness, we grew post-anthesis rice plants (Oryza sativa L. cv. Koshihikari) under control (25°C) or heat stress (30°C) conditions with or without antioxidant (dithiothreitol) treatment. The developing grains were analyzed for expression of NADPH oxidases, GA biosynthesis genes (OsGA3ox1, OsGA20ox1), ABA catabolism genes (OsABA8'OH1, OsABA8'OH2) and an α-amylase gene (OsAmy3E), endogenous H 2 O 2 content and the grain quality. In grains exposed to heat stress, the expression of NADPH oxidase genes (especially, OsRbohB, OsRbohD, OsRbohF and OsRbohI) and the ROS content increased. Heat stress also increased the expression of OsGA3ox1, OsGA20ox1, OsABA8'OH1, OsABA8'OH2 and OsAmy3E. On the other hand, dithiothreitol treatment reduced the effects of heat stress on the expression of these genes and significantly reduced grain chalkiness induced by heat stress. These results suggest that, similar to cereal seed germination mechanism, ROS produced under heat stress is involved in α-amylase induction in maturating rice grains through GA/ABA metabolism, and consequently caused grain chalkiness. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Genomic and phylogenetic evidence that Maize rough dwarf and Rice black-streaked dwarf fijiviruses should be classified as different geographic strains of a single species.

    Science.gov (United States)

    Xie, L; Lv, M-F; Yang, J; Chen, J-P; Zhang, H-M

    Maize rough dwarf disease (MRDD) has long been known as one of the most devastating viral diseases of maize worldwide and is caused by single or complex infection by four fijiviruses: Maize rough dwarf virus (MRDV) in Europe and the Middle East, Mal de Rio Cuarto virus (MRCV) in South America, rice black-streaked dwarf virus (RBSDV), and Southern rice black-streaked dwarf virus (SRBSDV or Rice black-streaked dwarf virus 2, RBSDV-2) in East Asia. These are currently classified as four distinct species in the genus Fijivirus, family Reoviridae, but their taxonomic status has been questioned. To help resolve this, the nucleotide sequences of the ten genomic segments of an Italian isolate of MRDV have been determined, providing the first complete genomic sequence of this virus. Its genome has 29144 nucleotides and is similar in organization to those of RBSDV, SRBSDV, and MRCV. The 13 ORFs always share highest identities (81.3-97.2%) with the corresponding ORFs of RBSDV and phylogenetic analyses of the different genome segments and ORFs all confirm that MRDV clusters most closely with RBSDV and that MRCV and SRBSDV are slightly more distantly related. The results suggest that MRDV and RBSDV should be classified as different geographic strains of the same virus species and we suggest the name cereal black-streaked dwarf fijivirus (CBSDV) for consideration.

  17. Homeolog loss and expression changes in natural populations of the recently and repeatedly formed allotetraploid Tragopogon mirus (Asteraceae

    Directory of Open Access Journals (Sweden)

    Soltis Pamela S

    2010-02-01

    Full Text Available Abstract Background Although polyploidy has long been recognized as a major force in the evolution of plants, most of what we know about the genetic consequences of polyploidy comes from the study of crops and model systems. Furthermore, although many polyploid species have formed repeatedly, patterns of genome evolution and gene expression are largely unknown for natural polyploid populations of independent origin. We therefore examined patterns of loss and expression in duplicate gene pairs (homeologs in multiple individuals from seven natural populations of independent origin of Tragopogon mirus (Asteraceae, an allopolyploid that formed repeatedly within the last 80 years from the diploids T. dubius and T. porrifolius. Results Using cDNA-AFLPs, we found differential band patterns that could be attributable to gene silencing, novel expression, and/or maternal/paternal effects between T. mirus and its diploid parents. Subsequent cleaved amplified polymorphic sequence (CAPS analyses of genomic DNA and cDNA revealed that 20 of the 30 genes identified through cDNA-AFLP analysis showed additivity, whereas nine of the 30 exhibited the loss of one parental homeolog in at least one individual. Homeolog loss (versus loss of a restriction site was confirmed via sequencing. The remaining gene (ADENINE-DNA GLYCOSYLASE showed ambiguous patterns in T. mirus because of polymorphism in the diploid parent T. dubius. Most (63.6% of the homeolog loss events were of the T. dubius parental copy. Two genes, NUCLEAR RIBOSOMAL DNA and GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE, showed differential expression of the parental homeologs, with the T. dubius copy silenced in some individuals of T. mirus. Conclusions Genomic and cDNA CAPS analyses indicated that plants representing multiple populations of this young natural allopolyploid have experienced frequent and preferential elimination of homeologous loci. Comparable analyses of synthetic F1 hybrids showed only

  18. Similar patterns of rDNA evolution in synthetic and recently formed natural populations of Tragopogon (Asteraceae allotetraploids

    Directory of Open Access Journals (Sweden)

    Soltis Pamela S

    2010-09-01

    Full Text Available Abstract Background Tragopogon mirus and T. miscellus are allotetraploids (2n = 24 that formed repeatedly during the past 80 years in eastern Washington and adjacent Idaho (USA following the introduction of the diploids T. dubius, T. porrifolius, and T. pratensis (2n = 12 from Europe. In most natural populations of T. mirus and T. miscellus, there are far fewer 35S rRNA genes (rDNA of T. dubius than there are of the other diploid parent (T. porrifolius or T. pratensis. We studied the inheritance of parental rDNA loci in allotetraploids resynthesized from diploid accessions. We investigate the dynamics and directionality of these rDNA losses, as well as the contribution of gene copy number variation in the parental diploids to rDNA variation in the derived tetraploids. Results Using Southern blot hybridization and fluorescent in situ hybridization (FISH, we analyzed copy numbers and distribution of these highly reiterated genes in seven lines of synthetic T. mirus (110 individuals and four lines of synthetic T. miscellus (71 individuals. Variation among diploid parents accounted for most of the observed gene imbalances detected in F1 hybrids but cannot explain frequent deviations from repeat additivity seen in the allotetraploid lines. Polyploid lineages involving the same diploid parents differed in rDNA genotype, indicating that conditions immediately following genome doubling are crucial for rDNA changes. About 19% of the resynthesized allotetraploid individuals had equal rDNA contributions from the diploid parents, 74% were skewed towards either T. porrifolius or T. pratensis-type units, and only 7% had more rDNA copies of T. dubius-origin compared to the other two parents. Similar genotype frequencies were observed among natural populations. Despite directional reduction of units, the additivity of 35S rDNA locus number is maintained in 82% of the synthetic lines and in all natural allotetraploids. Conclusions Uniparental reductions of

  19. The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).

    Science.gov (United States)

    Wang, Kai; Wambugu, Peterson W; Zhang, Bin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

    2015-09-20

    The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Phylogenetic analysis and protein structure modelling identifies distinct Ca(2+)/Cation antiporters and conservation of gene family structure within Arabidopsis and rice species.

    Science.gov (United States)

    Pittman, Jon K; Hirschi, Kendal D

    2016-12-01

    The Ca(2+)/Cation Antiporter (CaCA) superfamily is an ancient and widespread family of ion-coupled cation transporters found in nearly all kingdoms of life. In animals, K(+)-dependent and K(+)-indendent Na(+)/Ca(2+) exchangers (NCKX and NCX) are important CaCA members. Recently it was proposed that all rice and Arabidopsis CaCA proteins should be classified as NCX proteins. Here we performed phylogenetic analysis of CaCA genes and protein structure homology modelling to further characterise members of this transporter superfamily. Phylogenetic analysis of rice and Arabidopsis CaCAs in comparison with selected CaCA members from non-plant species demonstrated that these genes form clearly distinct families, with the H(+)/Cation exchanger (CAX) and cation/Ca(2+) exchanger (CCX) families dominant in higher plants but the NCKX and NCX families absent. NCX-related Mg(2+)/H(+) exchanger (MHX) and CAX-related Na(+)/Ca(2+) exchanger-like (NCL) proteins are instead present. Analysis of genomes of ten closely-related rice species and four Arabidopsis-related species found that CaCA gene family structures are highly conserved within related plants, apart from minor variation. Protein structures were modelled for OsCAX1a and OsMHX1. Despite exhibiting broad structural conservation, there are clear structural differences observed between the different CaCA types. Members of the CaCA superfamily form clearly distinct families with different phylogenetic, structural and functional characteristics, and therefore should not be simply classified as NCX proteins, which should remain as a separate gene family.

  1. Methylobacterium Species Promoting Rice and Barley Growth and Interaction Specificity Revealed with Whole-Cell Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF/MS Analysis.

    Directory of Open Access Journals (Sweden)

    Akio Tani

    Full Text Available Methylobacterium species frequently inhabit plant surfaces and are able to utilize the methanol emitted from plants as carbon and energy sources. As some of the Methylobacterium species are known to promote plant growth, significant attention has been paid to the mechanism of growth promotion and the specificity of plant-microbe interactions. By screening our Methylobacterium isolate collection for the high growth promotion effect in vitro, we selected some candidates for field and pot growth tests for rice and barley, respectively. We found that inoculation resulted in better ripening of rice seeds, and increased the size of barley grains but not the total yield. In addition, using whole-cell matrix-assister laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS analysis, we identified and classified Methylobacterium isolates from Methylobacterium-inoculated rice plants. The inoculated species could not be recovered from the rice plants, and in some cases, the Methylobacterium community structure was affected by the inoculation, but not with predomination of the inoculated species. The isolates from non-inoculated barley of various cultivars grown in the same field fell into just two species. These results suggest that there is a strong selection pressure at the species level of Methylobacterium residing on a given plant species, and that selection of appropriate species that can persist on the plant is important to achieve growth promotion.

  2. Formation of heterocyclic amines in Chinese marinated meat: effects of animal species and ingredients (rock candy, soy sauce and rice wine).

    Science.gov (United States)

    Wang, Pan; Hong, Yanting; Ke, Weixin; Hu, Xiaosong; Chen, Fang

    2017-09-01

    Heterocyclic aromatic amines (HAAs) are one type of neo-formed contaminants in protein-rich foods during heat processing. Recently, accumulative studies have focused on the formation of HAs in Western foods. However, there is little knowledge about the occurrence of HAAs in traditional Chinese foods. The objective of this study was to determinate the contents of main HAs in traditional marinated meat products by UPLC-MS/MS, and to investigate the effects of animal species and the ingredients (soy sauce, rock candy, and rice wine) on the formation of HAAs in marinated meats. Five HAs - 2-amino-3-methylimidazo[4,5-f]-quinolone (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4-dimethylimidazo[4,5-f]quinoxaline (MeIQ), 9H-pyrido[3,4-b]indole (Norharman) and l-methyl-9H-pyrido[3,4-b]indole (Harman) - were detected in 12 marinated meats, but 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was only found in three chicken marinates. The animal species and ingredients (soy sauce, rock candy and rice wine) have significant influence on the formation of HAAs in meat marinates. Beef had the highest content of total HAAs compared with pork, mutton and chicken. Meanwhile, soy sauce contributed to the formation of HAAs more greatly than rock candy, soy sauce, and rice wine. Choice of raw materials and optimisation of ingredients recipe should be become a critical point to control the HAAs formation in marinated meats. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Comparative analyses reveal high levels of conserved colinearity between the finger millet and rice genomes.

    Science.gov (United States)

    Srinivasachary; Dida, Mathews M; Gale, Mike D; Devos, Katrien M

    2007-08-01

    Finger millet is an allotetraploid (2n = 4x = 36) grass that belongs to the Chloridoideae subfamily. A comparative analysis has been carried out to determine the relationship of the finger millet genome with that of rice. Six of the nine finger millet homoeologous groups corresponded to a single rice chromosome each. Each of the remaining three finger millet groups were orthologous to two rice chromosomes, and in all the three cases one rice chromosome was inserted into the centromeric region of a second rice chromosome to give the finger millet chromosomal configuration. All observed rearrangements were, among the grasses, unique to finger millet and, possibly, the Chloridoideae subfamily. Gene orders between rice and finger millet were highly conserved, with rearrangements being limited largely to single marker transpositions and small putative inversions encompassing at most three markers. Only some 10% of markers mapped to non-syntenic positions in rice and finger millet and the majority of these were located in the distal 14% of chromosome arms, supporting a possible correlation between recombination and sequence evolution as has previously been observed in wheat. A comparison of the organization of finger millet, Panicoideae and Pooideae genomes relative to rice allowed us to infer putative ancestral chromosome configurations in the grasses.

  4. Comparative genomics analysis of rice and pineapple contributes to understand the chromosome number reduction and genomic changes in grasses

    Directory of Open Access Journals (Sweden)

    Jinpeng Wang

    2016-10-01

    Full Text Available Rice is one of the most researched model plant, and has a genome structure most resembling that of the grass common ancestor after a grass common tetraploidization ~100 million years ago. There has been a standing controversy whether there had been 5 or 7 basic chromosomes, before the tetraploidization, which were tackled but could not be well solved for the lacking of a sequenced and assembled outgroup plant to have a conservative genome structure. Recently, the availability of pineapple genome, which has not been subjected to the grass-common tetraploidization, provides a precious opportunity to solve the above controversy and to research into genome changes of rice and other grasses. Here, we performed a comparative genomics analysis of pineapple and rice, and found solid evidence that grass-common ancestor had 2n =2x =14 basic chromosomes before the tetraploidization and duplicated to 2n = 4x = 28 after the event. Moreover, we proposed that enormous gene missing from duplicated regions in rice should be explained by an allotetraploid produced by prominently divergent parental lines, rather than gene losses after their divergence. This means that genome fractionation might have occurred before the formation of the allotetraploid grass ancestor.

  5. Linking hydrogen-mediated boron toxicity tolerance with improvement of root elongation, water status and reactive oxygen species balance: a case study for rice.

    Science.gov (United States)

    Wang, Yu; Duan, Xingliang; Xu, Sheng; Wang, Ren; Ouyang, Zhaozeng; Shen, Wenbiao

    2016-12-01

    Boron is essential for plant growth but hazardous when present in excess. As the antioxidant properties of hydrogen gas (H 2 ) were recently described in plants, oxidative stress induced by excess boron was investigated along with other biological responses during rice (Oryza sativa) seed germination to study the beneficial role of H 2 METHODS: Rice seeds were pretreated with exogenous H 2 Using physiological, pharmacological and molecular approaches, the production of endogenous H 2 , growth status, reactive oxygen species (ROS) balance and relative gene expression in rice were measured under boron stress to investigate mechanisms of H 2 -mediated boron toxicity tolerance. In our test, boron-inhibited seed germination and seedling growth, and endogenous H 2 production, were obviously blocked by exogenously applying H 2 The re-establishment of ROS balance was confirmed by reduced lipid peroxidation and ROS accumulation. Meanwhile, activities of catalase (CAT) and peroxidase (POX) were increased. Suppression of pectin methylesterase (PME) activity and downregulation of PME transcripts by H 2 were consistent with the alleviation of root growth inhibition caused by boron. Water status was improved as well. This result was confirmed by the upregulation of genes encoding specific aquaporins (AQPs), the maintenance of low osmotic potential and high content of soluble sugar. Increased transcription of representative AQP genes (PIP2;7 in particular) and BOR2 along with decreased BOR1 mRNA may contribute to lowering boron accumulation. Hydrogen provides boron toxicity tolerance mainly by improving root elongation, water status and ROS balance. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Simultaneous separation and determination of six arsenic species in rice by anion-exchange chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Ma, Li; Yang, Zhaoguang; Tang, Jie; Wang, Lin

    2016-06-01

    The simultaneous separation and determination of arsenite As(III), arsenate As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) in rice samples have been carried out in one single anion-exchange column run by high-performance liquid chromatography with inductively coupled plasma mass spectrometry. To estimate the effect of variables on arsenic (As) speciation, the chromatographic conditions including type of competing anion, ionic strength, pH of elution buffer, and flow rate of mobile phase have been investigated by a univariate approach. Under the optimum chromatographic conditions, baseline separation of six As species has been achieved within 10 min by gradient elution program using 4 mM NH4 HCO3 at pH 8.6 as mobile phase A and 4 mM NH4 HCO3 , 40 mM NH4 NO3 at pH 8.6 as mobile phase B. The method detection limits for As(III), As(V), MMA, DMA, AsB, and AsC were 0.4, 0.9, 0.2, 0.4, 0.5, and 0.3 μg/kg, respectively. The proposed method has been applied to separation and quantification of As species in real rice samples collected from Hunan Province, China. The main As species detected in all samples were As(III), As(V) and DMA, with inorganic As accounting for over 80% of total As in these samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. ABNORMAL INFLORESCENCE MERISTEM1 Functions in Salicylic Acid Biosynthesis to Maintain Proper Reactive Oxygen Species Levels for Root Meristem Activity in Rice.

    Science.gov (United States)

    Xu, Lei; Zhao, Hongyu; Ruan, Wenyuan; Deng, Minjuan; Wang, Fang; Peng, Jinrong; Luo, Jie; Chen, Zhixiang; Yi, Keke

    2017-03-01

    Root meristem activity determines root growth and root architecture and consequently affects water and nutrient uptake in plants. However, our knowledge about the regulation of root meristem activity in crop plants is very limited. Here, we report the isolation and characterization of a short root mutant in rice ( Oryza sativa ) with reduced root meristem activity. This root growth defect is caused by a mutation in ABNORMAL INFLORESCENCE MERISTEM1 ( AIM1 ), which encodes a 3-hydroxyacyl-CoA dehydrogenase, an enzyme involved in β-oxidation. The reduced root meristem activity of aim1 results from reduced salicylic acid (SA) levels and can be rescued by SA application. Furthermore, reduced SA levels are associated with reduced levels of reactive oxygen species (ROS) in aim1 , likely due to increased expression of redox and ROS-scavenging-related genes, whose increased expression is (at least in part) caused by reduced expression of the SA-inducible transcriptional repressors WRKY62 and WRKY76. Like SA, ROS application substantially increased root length and root meristem activity in aim1 These results suggest that AIM1 is required for root growth in rice due to its critical role in SA biosynthesis: SA maintains root meristem activity through promoting ROS accumulation by inducing the activity of WRKY transcriptional repressors, which repress the expression of redox and ROS-scavenging genes. © 2017 American Society of Plant Biologists. All rights reserved.

  8. Characterization and evolutionary analysis of ent-kaurene synthase like genes from the wild rice species Oryza rufipogon.

    Science.gov (United States)

    Toyomasu, Tomonobu; Miyamoto, Koji; Shenton, Matthew R; Sakai, Arisa; Sugawara, Chizu; Horie, Kiyotaka; Kawaide, Hiroshi; Hasegawa, Morifumi; Chuba, Masaru; Mitsuhashi, Wataru; Yamane, Hisakazu; Kurata, Nori; Okada, Kazunori

    2016-11-18

    Cultivated rice (Oryza sativa) possesses various labdane-related diterpene synthase genes, homologs of ent-copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS) that are responsible for the biosynthesis of phytohormone gibberellins. The CPS homologs and KS like (KSL) homologs successively converted geranylgeranyl diphosphate to cyclic diterpene hydrocarbons via ent-copalyl diphosphate or syn-copalyl diphosphate in O. sativa. Consequently, a variety of labdane-related diterpenoids, including phytoalexin phytocassanes, momilactones and oryzalexins, have been identified from cultivated rice. Our previous report indicated that the biosynthesis of phytocassanes and momilactones is conserved in Oryza rufipogon, the progenitor of Asian cultivated rice. Moreover, their biosynthetic gene clusters, containing OsCPS2 and OsKSL7 for phytocassane biosynthesis and OsCPS4 and OsKSL4 for momilactone biosynthesis, are also present in the O. rufipogon genome. We herein characterized O. rufipogon homologs of OsKSL5, OsKSL6, OsKSL8 responsible for oryzalexin S biosynthesis, and OsKSL10 responsible for oryzalexins A-F biosynthesis, to obtain more evolutionary insight into diterpenoid biosynthesis in O. sativa. Our phytoalexin analyses showed that no accumulation of oryzalexins was detected in extracts from O. rufipogon leaf blades. In vitro functional analyses indicated that unlike OsKSL10, O. rufipogon KSL10 functions as an ent-miltiradiene synthase, which explains the lack of accumulation of oryzalexins A-F in O. rufipogon. The different functions of KSL5 and KSL8 in O. sativa japonica to those in indica are conserved in each type of O. rufipogon, while KSL6 functions (ent-isokaurene synthases) are well conserved. Our study suggests that O. sativa japonica has evolved distinct specialized diterpenoid metabolism, including the biosynthesis of oryzalexins. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Cytoplasmic and Genomic Effects on Meiotic Pairing in Brassica Hybrids and Allotetraploids from Pair Crosses of Three Cultivated Diploids

    Science.gov (United States)

    Cui, Cheng; Ge, Xianhong; Gautam, Mayank; Kang, Lei; Li, Zaiyun

    2012-01-01

    Interspecific hybridization and allopolyploidization contribute to the origin of many important crops. Synthetic Brassica is a widely used model for the study of genetic recombination and “fixed heterosis” in allopolyploids. To investigate the effects of the cytoplasm and genome combinations on meiotic recombination, we produced digenomic diploid and triploid hybrids and trigenomic triploid hybrids from the reciprocal crosses of three Brassica diploids (B. rapa, AA; B. nigra, BB; B. oleracea, CC). The chromosomes in the resultant hybrids were doubled to obtain three allotetraploids (B. juncea, AA.BB; B. napus, AA.CC; B. carinata, BB.CC). Intra- and intergenomic chromosome pairings in these hybrids were quantified using genomic in situ hybridization and BAC-FISH. The level of intra- and intergenomic pairings varied significantly, depending on the genome combinations and the cytoplasmic background and/or their interaction. The extent of intragenomic pairing was less than that of intergenomic pairing within each genome. The extent of pairing variations within the B genome was less than that within the A and C genomes, each of which had a similar extent of pairing. Synthetic allotetraploids exhibited nondiploidized meiotic behavior, and their chromosomal instabilities were correlated with the relationship of the genomes and cytoplasmic background. Our results highlight the specific roles of the cytoplasm and genome to the chromosomal behaviors of hybrids and allopolyploids. PMID:22505621

  10. Rice microstructure

    Science.gov (United States)

    An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...

  11. The temporal and species dynamics of photosynthetic acclimation in flag leaves of rice (Oryza sativa) and wheat (Triticum aestivum) under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.; Zeng, Q.; Xie, Z.; Tang, H.; Zhu, C. (Chinese Academy of Sciences. State Key Lab. of Soil and Sustainable Agriculture, Institute of Soil Science, Nanjing (China)); Hasegawa, T. (National Institute for Agro-Environmental Sciences. Agro-Meteorology Div., Tsukuba (Japan)); Ziska, L. (Crop Systems and Global Change Lab., Beltsville, MD (United States)); Jia, X. (Chinese Academic of Sciences/Nanjing Botanical Garden Memorial Sun Yat-Sen. Jiangsu Institute of Botany, Nanjing (China))

    2012-07-15

    In this study, we tested for the temporal occurrence of photosynthetic acclimation to elevated [CO{sub 2}] in the flag leaf of two important cereal crops, rice and wheat. In order to characterize the temporal onset of acclimation and the basis for any observed decline in photosynthetic rate, we characterized net photosynthesis, g{sub s}, g{sub m}, C{sub i}/C{sub a}, C{sub i}/C{sub c}, V{sub cmax}, J{sub max}, cell wall thickness, content of Rubisco, cytochrome (Cyt) f, N, chlorophyll and carbohydrate, mRNA expression for rbcL and petA, activity for Rubisco, sucrose phosphate synthase (SPS) and sucrose synthase (SS) at full flag expansion, mid-anthesis and the late grain-filling stage. No acclimation was observed for either crop at full flag leaf expansion. However, at the mid-anthesis stage, photosynthetic acclimation in rice was associated with RuBP carboxylation and regeneration limitations, while wheat only had the carboxylation limitation. By grain maturation, the decline of Rubisco content and activity had contributed to RuBP carboxylation limitation of photosynthesis in both crops at elevated [CO{sub 2}]; however, the sharp decrease of Rubisco enzyme activity played a more important role in wheat. Although an increase in non-structural carbohydrates did occur during these later stages, it was not consistently associated with changes in SPS and SS or photosynthetic acclimation. Rather, over time elevated [CO{sub 2}] appeared to enhance the rate of N degradation and senescence so that by late-grain fill, photosynthetic acclimation to elevated [CO{sub 2}] in the flag leaf of either species was complete. These data suggest that the basis for photosynthetic acclimation with elevated [CO{sub 2}] may be more closely associated with enhanced rates of senescence, and, as a consequence, may be temporally dynamic, with significant species variation. (Author)

  12. Report of the key comparison CCQM-K108 determination of arsenic species, total arsenic and cadmium in brown rice flour

    Science.gov (United States)

    Hioki, Akiharu; Narukawa, Tomohiro; Inagaki, Kazumi; Miyashita, Shinichi; Kotzeva, Boriana; Kakoulides, Elias; Sxoina, Vasiliki; Fung, W. H.; Choi, Y. Y.; Yau, H. P.; Tsoi, Y. T.; Lee, C. L.; Kong, M. F.; Shin, Richard; Juan, Wang; Sin Yee, Ng; Uribe, Christian; Marques Rodrigues, Janaína; Caciano de Sena, Rodrigo; Silva Dutra, Emily; Bergamaschi, Luigi; Giordani, Laura; D'Agostino, Giancarlo; Valiente, Liliana; Horvat, Milena; Jacimovic, Radojko; Oduor Okumu, Tom; Kang'Iri, Jacqueline; Owiti Orwa, Tabitha; Chao, Wei; Jingbo, Chao; Taebunpakul, Sutthinun; Yafa, Charun; Kaewkhomdee, Nattikarn; Chailap, Benjamat; Pharat, Yanee; Phukphattanachai, Pranee; Turk, Gregory C.; Long, Stephen; Murphy, K. E.; Davis, Clay; Ellisor, Michael; Merrick, Jeffrey; White, Ian; Saxby, David; Linsky, S. M.; Barzev, A.; Botha, A.

    2015-01-01

    The CCQM-K108 key comparison was organised by the Inorganic Analysis Working Group (IAWG) of CCQM to test the abilities of national metrology institutes (NMIs) or designated institutes (DIs) to measure the mass fractions of arsenic species, total arsenic and cadmium in brown rice flour. The National Metrology Institute of Japan (NMIJ) acted as the coordinating laboratory. The participants used different measurement methods, though most of them used inductively coupled plasma mass spectrometry (ICP-MS) or isotope-dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) for Cd and ICP-MS for total arsenic. Regarding arsenic speciation, all participants used ICP-MS coupled with liquid chromatography (LC). Accounting for relative expanded uncertainty, comparability of measurement results for each of total arsenic and cadmium was successfully demonstrated by the participating NMIs or DIs for the measurement of the measurand at the level of less than 0.5 mg/kg. Regarding arsenic species (inorganic arsenic and dimethylarsinic acid (DMAA)), there was, however, a measurement problem still to be solved and that part of CCQM-K108 will be repeated. It is expected that arsenic, cadmium and other metals at mass fractions greater than approximately 0.1 mg/kg in rice flour can be determined by each participant using the same technique(s) employed for this key comparison to achieve similar uncertainties mentioned in the present report. Furthermore, the results of this key comparison can be utilised along with the IAWG core capability approach. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  13. Biomphalaria species distribution and its effect on human Schistosoma mansoni infection in an irrigated area used for rice cultivation in northeast Brazil

    Directory of Open Access Journals (Sweden)

    Delmany Moitinho Barboza

    2012-09-01

    Full Text Available The role of irrigated areas for the spread of schistosomiasis is of worldwide concern. The aim of the present study was to investigate the spatial distribution of the intermediate snail host Biomphalaria in an area highly endemic for schistosomiasis due to Schistosoma mansoni, evaluating the relationship between irrigation and types of natural water sources on one hand, and the influence of place and time of water exposure on the intensity of human infection on the other. A geographical information system (GIS was used to map the distribution of the intermediate snail hosts in Ilha das Flores, Sergipe, Brazil, combined with a clinical/epidemiological survey. We observed a direct correlation between the intensity of human infection with S. mansoni and irrigation projects. Malacological studies to identify snail species and infection rates showed that B. glabrata is the main species responsible for human schistosomiasis in the municipality, but that B. straminea also plays a role. Our results provide evidence for a competitive selection between the two snail species in rice fields with a predominance of B. glabrata in irrigation systems and B. straminea in natural water sources.

  14. Population genomics identifies the origin and signatures of selection of Korean weedy rice

    OpenAIRE

    He, Qiang; Kim, Kyu?Won; Park, Yong?Jin

    2016-01-01

    Summary Weedy rice is the same biological species as cultivated rice (Oryza sativa); it is also a noxious weed infesting rice fields worldwide. Its formation and population?selective or ?adaptive signatures are poorly understood. In this study, we investigated the phylogenetics, population structure and signatures of selection of Korean weedy rice by determining the whole genomes of 30 weedy rice, 30 landrace rice and ten wild rice samples. The phylogenetic tree and results of ancestry infere...

  15. Ethylene is not involved in adaptive responses to flooding in the Amazonian wild rice species Oryza grandiglumis.

    Science.gov (United States)

    Okishio, Takuma; Sasayama, Daisuke; Hirano, Tatsuya; Akimoto, Masahiro; Itoh, Kazuyuki; Azuma, Tetsushi

    2015-02-01

    The Amazonian wild rice Oryza grandiglumis has two contrasting adaptation mechanisms to flooding submergence: a quiescence response to complete submergence at the seedling stage and an escape response based on internodal elongation to partial submergence at the mature stage. We investigated possible factors that trigger these responses. In stem segments excised from mature O. grandiglumis plants, complete submergence only slightly promoted internodal elongation with increased ethylene levels in the internodes, while partial submergence substantially promoted internodal elongation without increased ethylene levels in the internodes. Incubation of non-submerged stem segments under a continuous flow of humidified ethylene-free air promoted internodal elongation to the same extent as that observed for partially submerged segments. Applied ethylene had little effect on the internodal elongation of non-submerged segments irrespective of humidity conditions. These results indicate that the enhanced internodal elongation of submerged O. grandiglumis plants is not triggered by ethylene accumulated during submergence but by the moist surroundings provided by submergence. The growth of shoots in O. grandiglumis seedlings was not promoted by ethylene or complete submergence, as is the case in O. sativa cultivars possessing the submergence-tolerant gene SUB1A. However, because the genome of O. grandiglumis lacks the SUB1A gene, the quiescence response of O. grandiglumis seedlings to complete submergence may be regulated by a mechanism distinct from that involved in the response of submergence-tolerant O. sativa cultivars. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. A Computational analysis on Lectin and Histone H1 protein of different pulse species as well as comparative study with rice for balanced diet.

    Science.gov (United States)

    Hasan, Md Anayet; Mannan, Adnan; Alam, Rashel; Islam, Md Taohidul; Amin, Mohammad Al; Khan, Md Sarowar Jahan; Islam, Md Ashraful; Muzahid, Nazmul Hasan

    2012-01-01

    The issue of balanced nutrition is of great concern to human. Meat and fish are the best sources of protein. The affordability of these resources for people in developing countries is less. Thus, there is an increasing interest in pulses and its derivates as an alternative to fish and meat. Lectin and histone H1 are the most common proteins in various pulses and our interest is in identifying the dominant essential amino acids in them for use as supplements. However, actin and lectin are common among Oryza Sativa and cicer arietinum. We describe the amount of lectin and histone H1 in cicer arietinum, Lens culinaris and Pisum sativum in a comparative manner. cicer arietinum was found to contain more essential amino acids than Lens culinaris and Pisum sativum. The secondary structures of lectin and histone H1 protein were analyzed to gain functional inferences in these species. The comparative study shows the relatively poor presence of the amino acid methionine in most pulses. However, Oryza Sativa was found to contain sufficient methionine. The study shows that pulses (especially cicer arietinum) were a suitable alternative source to meat and fish for Lectin and Histone H1 balance. Hence, pulses could be suggested with rice for balanced protein diet.

  17. Efficient generation of volatile species for cadmium analysis in seafood and rice samples by a modified chemical vapor generation system coupled with atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Yang, Xin-an; Chi, Miao-bin; Wang, Qing-qing; Zhang, Wang-bing

    2015-01-01

    Highlights: • We develop a modified chemical vapor generation method coupled with AFS for the determination of cadmium. • The response of Cd could be increased at least four-fold compared to conventional thiourea and Co(II) system. • A simple mixing sequences experiment is designed to study the reaction mechanism. • The interference of transition metal ions can be easily eliminated by adding DDTC. • The method is successfully applied in seafood samples and rice samples. - Abstract: A vapor generation procedure to determine Cd by atomic fluorescence spectrometry (AFS) has been established. Volatile species of Cd are generated by following reaction of acidified sample containing Fe(II) and L-cysteine (Cys) with sodium tetrahydroborate (NaBH 4 ). The presence of 5 mg L −1 Fe(II) and 0.05% m/v Cys improves the efficiency of Cd vapor generation substantially about four-fold compared with conventional thiourea and Co(II) system. Three experiments with different mixing sequences and reaction times are designed to study the reaction mechanism. The results document that the stability of Cd(II)–Cys complexes is better than Cys–THB complexes (THB means NaBH 4 ) while the Cys–THB complexes have more contribution to improve the Cd vapor generation efficiency than Cd(II)–Cys complexes. Meanwhile, the adding of Fe(II) can catalyze the Cd vapor generation. Under the optimized conditions, the detection limit of Cd is 0.012 μg L −1 ; relative standard deviations vary between 0.8% and 5.5% for replicate measurements of the standard solution. In the presence of 0.01% DDTC, Cu(II), Pb(II) and Zn(II) have no significant influence up to 5 mg L −1 , 10 mg L −1 and 10 mg L −1 , respectively. The accuracy of the method is verified through analysis of the certificated reference materials and the proposed method has been applied in the determination of Cd in seafood and rice samples

  18. Efficient generation of volatile species for cadmium analysis in seafood and rice samples by a modified chemical vapor generation system coupled with atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xin-an, E-mail: 13087641@qq.com; Chi, Miao-bin, E-mail: 1161306667@qq.com; Wang, Qing-qing, E-mail: wangqq8812@163.com; Zhang, Wang-bing, E-mail: ahutwbzh@163.com

    2015-04-15

    Highlights: • We develop a modified chemical vapor generation method coupled with AFS for the determination of cadmium. • The response of Cd could be increased at least four-fold compared to conventional thiourea and Co(II) system. • A simple mixing sequences experiment is designed to study the reaction mechanism. • The interference of transition metal ions can be easily eliminated by adding DDTC. • The method is successfully applied in seafood samples and rice samples. - Abstract: A vapor generation procedure to determine Cd by atomic fluorescence spectrometry (AFS) has been established. Volatile species of Cd are generated by following reaction of acidified sample containing Fe(II) and L-cysteine (Cys) with sodium tetrahydroborate (NaBH{sub 4}). The presence of 5 mg L{sup −1} Fe(II) and 0.05% m/v Cys improves the efficiency of Cd vapor generation substantially about four-fold compared with conventional thiourea and Co(II) system. Three experiments with different mixing sequences and reaction times are designed to study the reaction mechanism. The results document that the stability of Cd(II)–Cys complexes is better than Cys–THB complexes (THB means NaBH{sub 4}) while the Cys–THB complexes have more contribution to improve the Cd vapor generation efficiency than Cd(II)–Cys complexes. Meanwhile, the adding of Fe(II) can catalyze the Cd vapor generation. Under the optimized conditions, the detection limit of Cd is 0.012 μg L{sup −1}; relative standard deviations vary between 0.8% and 5.5% for replicate measurements of the standard solution. In the presence of 0.01% DDTC, Cu(II), Pb(II) and Zn(II) have no significant influence up to 5 mg L{sup −1}, 10 mg L{sup −1}and 10 mg L{sup −1}, respectively. The accuracy of the method is verified through analysis of the certificated reference materials and the proposed method has been applied in the determination of Cd in seafood and rice samples.

  19. Ectopic Expression of Hrf1 Enhances Bacterial Resistance via Regulation of Diterpene Phytoalexins, Silicon and Reactive Oxygen Species Burst in Rice

    Science.gov (United States)

    Zhong, Weigong; Yang, Jie; Okada, Kazunori; Yamane, Hisakazu; Zhang, Lei; Wang, Guang; Wang, Dong; Xiao, Shanshan; Chang, Shanshan; Qian, Guoliang; Liu, Fengquan

    2012-01-01

    Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo), Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpinXoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H2O2) concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H2O2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens. PMID:22970151

  20. Ectopic expression of Hrf1 enhances bacterial resistance via regulation of diterpene phytoalexins, silicon and reactive oxygen species burst in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo, Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpin(Xoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H(2O(2 concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM and energy-dispersive X-ray spectrometer (EDS. Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H(2O(2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens.

  1. Broadening the genetic base of Abyssinian mustard (Brassica carinata A. Braun through introgression of genes from related allotetraploid species

    Directory of Open Access Journals (Sweden)

    Farooq A. Sheikh

    2014-07-01

    Full Text Available Brassica carinata (BBCC, 2n=34 has still to emerge as a major oilseed crop owing to poor agronomic attributes like long stature, long maturity duration and low seed yield. The restricted amount of genetic variability available in natural B. carinata necessitates utilization of new sources of variability for broadening its genetic base. Interspecific hybridization followed by selection in selfed and back cross progenies was employed to generate useful variability into B. carinata cv ˈPC5ˈ from elite lines of Brassica napus (AACC, 2n=38 and Brassica juncea (AABB, 2n=36. The morphological evaluation of 24 stable introgressed progenies revealed wide range of variability for key economic traits. The progenies with mean maturity duration of 161 ± 2.1 days, short stature of 139.5 ± 6.5 cm and seed yield per plant of 18.6 ± 2.0 g in comparison to the corresponding figures of 168 ± 4.6 days, 230.6 ± 12.7 cm and 12.0 ± 2.4 g in ˈPC5ˈ (recurrent parent were recovered. Diversity analysis at morphological level revealed that 22 out of 24 stable introgressed progenies were grouped with B. carinata ˈPC5ˈ at average taxonomic distance of 1.19. The diversity at molecular level using 25 polymorphic and reproducible RAPD primers revealed that 19 out of 21 introgressed progenies grouped with B. carinata ˈPC5ˈ at a similarity coefficient of 0.68. The clusters in general represent a wide range of genetic diversity in the back cross lines of B. carinata as a result of introgression of genes from elite lines of B. napus and B. juncea parents.

  2. Chromosome isolation by flow sorting in Aegilops umbellulata and Ae. comosa and their allotetraploid hybrids Ae. biuncialis and Ae. geniculata.

    Directory of Open Access Journals (Sweden)

    István Molnár

    Full Text Available This study evaluates the potential of flow cytometry for chromosome sorting in two wild diploid wheats Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata. Flow karyotypes obtained after the analysis of DAPI-stained chromosomes were characterized and content of chromosome peaks was determined. Peaks of chromosome 1U could be discriminated in flow karyotypes of Ae. umbellulata and Ae. biuncialis and the chromosome could be sorted with purities exceeding 95%. The remaining chromosomes formed composite peaks and could be sorted in groups of two to four. Twenty four wheat SSR markers were tested for their position on chromosomes of Ae. umbellulata and Ae. comosa using PCR on DNA amplified from flow-sorted chromosomes and genomic DNA of wheat-Ae. geniculata addition lines, respectively. Six SSR markers were located on particular Aegilops chromosomes using sorted chromosomes, thus confirming the usefulness of this approach for physical mapping. The SSR markers are suitable for marker assisted selection of wheat-Aegilops introgression lines. The results obtained in this work provide new opportunities for dissecting genomes of wild relatives of wheat with the aim to assist in alien gene transfer and discovery of novel genes for wheat improvement.

  3. Benthic macroinvertebrates in Italian rice fields

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    Daniela Lupi

    2013-02-01

    Full Text Available Rice fields can be considered man-managed temporary wetlands. Five rice fields handled with different management strategies, their adjacent channels, and a spring were analysed by their benthic macroinvertebrate community to i evaluate the role of rice agroe- cosystem in biodiversity conservation; ii find indicator species which can be used to compare the ecological status of natural wetlands with rice agroecosystems; and iii find the influence of environmental variables on biodiversity. Different methods of data analysis with increasing degree of complexity – from diversity index up to sophisticated multivariate analysis – were used. The investigation provided a picture of benthic macroinvertebrates inhabiting rice agroecosystems where 173 taxa were identified, 89 of which detected in rice paddies. Among them, 4 phyla (Mollusca, Annelida, Nematomorpha, and Arthropoda, 8 classes (Bivalvia, Gastropoda, Oligochaeta, Hirudinea, Gordioida, Insecta, Branchiopoda, and Malacostraca, 24 orders, 68 families, 127 genera and 159 species have been found. Ten threatened and 3 invasive species were detected in the habitats examined. The information obtained by the different methods of data analysis allowed a more comprehensive view on the value of the components of rice agroecosystems. Data analyses highlighted significant differences between habitats (feeding channel and rice field, with higher diversity observed in channels, and emphasised the role of the water chemical-physical parameters. The period of water permanence in rice fields resulted to be only one of the factors influencing the community of benthic macroinvertebrates. The presence of rare/endangered species allowed characterising some stations, but it was less informative about management strategies in rice paddies because most of these species were absent in rice fields.

  4. Rice agroecosystem and the maintenance of biodiversity

    International Nuclear Information System (INIS)

    Ahyaudin Ali

    2002-01-01

    Rice fields are a special type of wetland. They are shallow, constantly disturbed and experience extremes in temperature and dissolved oxygen content. They receive nutrients in the form of fertilizers during rice cultivation. Rice fields; support a variety of flora and fauna that have adapted and adjusted themselves to the extreme conditions. Since rice fields also support populations of wild fish, rice?fish integration should be done in order to optimize land use and provide supplementary income to farmers. Rice?fish farming encourages farmers to judiciously apply pesticides and herbicides in their fields thus helping to control excessive and unwarranted use of these chemicals. Rice fields also support many migratory and nonmigratory bird species and provides habitat for small mammals. Thus the rice agroecosystem helps to maintain aquatic biodiversity. The Muda rice agroecosystem consists of a troika of interconnected ecosystems. The troika consisting of reservoirs, the connecting network of canals and the rice fields; should be investigated further. This data is needed for informed decision-making concerning development and management of the system so that productivity and biodiversity can be maintained and sustained. (Author)

  5. Cell fusion as a tool for rice improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y; Kyozuka, J; Terada, R; Nishibayashi, S; Shimamoto, K [Plantech Research Institute, Kamoshida, Midori-ku, Yokohama (Japan)

    1990-01-01

    Full text: Cell fusion offers a unique opportunity to hybridize sexually incompatible species and to mix cytoplasmic genomes in higher plants. Recent progress in plant regeneration from rice protoplasts facilitates an evaluation of the cell fusion method for rice improvement. By using electrofusion of protoplasts, we obtained hybrid/cybrid plants of the following combinations: Hybrids of rice x barnyard grass (E. oryzicola); Hybrids of rice x wild Oryza species; Cybrids of rice with transferred cms cytoplasm. For the latter, protoplasts irradiated with 70 krad x-rays were used. (author)

  6. Arsenic accumulation in rice: Consequences of rice genotypes and management practices to reduce human health risk.

    Science.gov (United States)

    Islam, Shofiqul; Rahman, Mohammad Mahmudur; Islam, M R; Naidu, Ravi

    2016-11-01

    Rice is an essential staple food and feeds over half of the world's population. Consumption of rice has increased from limited intake in Western countries some 50years ago to major dietary intake now. Rice consumption represents a major route for inorganic arsenic (As) exposure in many countries, especially for people with a large proportion of rice in their daily diet as much as 60%. Rice plants are more efficient in assimilating As into its grains than other cereal crops and the accumulation may also adversely affect the quality of rice and their nutrition. Rice is generally grown as a lowland crop in flooded soils under reducing conditions. Under these conditions the bioavailability of As is greatly enhanced leading to excessive As bioaccumulation compared to that under oxidizing upland conditions. Inorganic As species are carcinogenic to humans and even at low levels in the diet pose a considerable risk to humans. There is a substantial genetic variation among the rice genotypes in grain-As accumulation as well as speciation. Identifying the extent of genetic variation in grain-As concentration and speciation of As compounds are crucial to determining the rice varieties which accumulate low inorganic As. Varietal selection, irrigation water management, use of fertilizer and soil amendments, cooking practices etc. play a vital role in reducing As exposure from rice grains. In the meantime assessing the bioavailability of As from rice is crucial to understanding human health exposure and reducing the risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... tics, led us to predict that pollen cell abortion in this type of rice when ... averages of natural day-light-lengths and temperatures were used. A natural long ... blocks were allowed to grow under natural growth conditions (which.

  8. Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages

    OpenAIRE

    Rolon, A. S.; Godoy, R. S.; Maltchik, L.

    2017-01-01

    Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of n...

  9. Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

    Directory of Open Access Journals (Sweden)

    Gopala Krishnan S

    Full Text Available BACKGROUND: Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. RESULTS: We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts. Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. CONCLUSIONS: Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.

  10. Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

    Science.gov (United States)

    Krishnan S, Gopala; Waters, Daniel L E; Henry, Robert J

    2014-01-01

    Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts). Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.

  11. Diversity and population dynamics of pests and predators in irrigated rice fields with treated and untreated pesticide.

    Science.gov (United States)

    Rattanapun, W

    2012-01-01

    The monitoring of rice pests and their predators in pesticide untreated and treated rice fields was conducted at the southern of Thailand. Twenty-two species in 15 families and 6 orders of rice pests were sampled from untreated rice field. For treated rice field, 22 species in 14 families and 5 orders of rice pest were collected. Regardless of treatment type, dominant species and individual number of rice pest varied to physiological stage of rice. Lepidopteran pests had highest infestation during the vegetative stage of rice growth, while hemipteran pests composed of hopper species (Hemipetra: Auchenorrhyncha) and heteropteran species (Hemiptera: Heteroptera) were dominant groups during the reproductive stage and grain formation and ripening stage of rice growth. In contrast, dominant species of predator did not change throughout rice growing season. There were 35 species in 25 families and seven orders and 40 species in 29 families and seven orders of predators collected from untreated and treated rice field, respectively. Major predators of both rice fields were Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae), Tetragnatha sp. (Araneae: Tetragnathidae) and Agriocnemis pygmaea Rambur (Odonata: Agrionidae). The population dynamic of predators were not related with rice pest population in both treatments. However, the fluctuation of population pattern of rice pests in the untreated treatment were more distinctly synchronized with their predators than that of the treated treatment. There were no significant differences in the total number of rice pest and predator between two treatments at vegetative and reproductive stages of rice growth. Untreated rice field had a higher population number of predator and a lower population number of rice pest than that of treated rice field during grain formation and ripening stages. These results indicated the ago-ecosystem balance in rice fields could be produced through minimal pesticide application, in order to allow

  12. RPAN: rice pan-genome browser for ∼3000 rice genomes.

    Science.gov (United States)

    Sun, Chen; Hu, Zhiqiang; Zheng, Tianqing; Lu, Kuangchen; Zhao, Yue; Wang, Wensheng; Shi, Jianxin; Wang, Chunchao; Lu, Jinyuan; Zhang, Dabing; Li, Zhikang; Wei, Chaochun

    2017-01-25

    A pan-genome is the union of the gene sets of all the individuals of a clade or a species and it provides a new dimension of genome complexity with the presence/absence variations (PAVs) of genes among these genomes. With the progress of sequencing technologies, pan-genome study is becoming affordable for eukaryotes with large-sized genomes. The Asian cultivated rice, Oryza sativa L., is one of the major food sources for the world and a model organism in plant biology. Recently, the 3000 Rice Genome Project (3K RGP) sequenced more than 3000 rice genomes with a mean sequencing depth of 14.3×, which provided a tremendous resource for rice research. In this paper, we present a genome browser, Rice Pan-genome Browser (RPAN), as a tool to search and visualize the rice pan-genome derived from 3K RGP. RPAN contains a database of the basic information of 3010 rice accessions, including genomic sequences, gene annotations, PAV information and gene expression data of the rice pan-genome. At least 12 000 novel genes absent in the reference genome were included. RPAN also provides multiple search and visualization functions. RPAN can be a rich resource for rice biology and rice breeding. It is available at http://cgm.sjtu.edu.cn/3kricedb/ or http://www.rmbreeding.cn/pan3k. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. Influence of plant species and environmental conditions on epiphytic and endophytic pink-pigmented facultative methylotrophic bacterial populations associated with field-grown rice cultivars.

    Science.gov (United States)

    Madhaiyan, Munusamy; Poonguzhali, Selvaraj; Sa, Tongmin

    2007-10-01

    The total methylotrophic population associated with rice plants from different cultivars was enumerated at three different stages: vegetative, flowering, and harvesting. The bacterial population in the leaf, rhizosphere soil, endophytic in the stem and roots, and epiphytic in the florets and grains were determined from four rice cultivars, Il-mi, Nam-pyeoung, O-dae, and Dong-jin, sampled from three different field sites. The methylotrophic bacteria isolated on AMS media containing 0.5% methanol as the sole carbon source uniformly showed three distinct morphologies, which were recorded as separate groups and their distribution among the various samples was determined using the ecophysiological index. The growth stage at the time of sampling had a more significant effect on the methylotrophic population and their distribution than the field site or cultivar. A similar effect was also observed for the PPFMs, where their population in different plant parts increased from V10 to R4 and then decreased towards stage R9. A canonical discriminant analysis of the PPFM population from different parts of rice showed clear variations among the cultivars, sampled sites, and growth stages, although the variations were more prominent among the growth stages.

  14. Re-exploration of U's Triangle Brassica Species Based on Chloroplast Genomes and 45S nrDNA Sequences.

    Science.gov (United States)

    Kim, Chang-Kug; Seol, Young-Joo; Perumal, Sampath; Lee, Jonghoon; Waminal, Nomar Espinosa; Jayakodi, Murukarthick; Lee, Sang-Choon; Jin, Seungwoo; Choi, Beom-Soon; Yu, Yeisoo; Ko, Ho-Cheol; Choi, Ji-Weon; Ryu, Kyoung-Yul; Sohn, Seong-Han; Parkin, Isobel; Yang, Tae-Jin

    2018-05-09

    The concept of U's triangle, which revealed the importance of polyploidization in plant genome evolution, described natural allopolyploidization events in Brassica using three diploids [B. rapa (A genome), B. nigra (B), and B. oleracea (C)] and derived allotetraploids [B. juncea (AB genome), B. napus (AC), and B. carinata (BC)]. However, comprehensive understanding of Brassica genome evolution has not been fully achieved. Here, we performed low-coverage (2-6×) whole-genome sequencing of 28 accessions of Brassica as well as of Raphanus sativus [R genome] to explore the evolution of six Brassica species based on chloroplast genome and ribosomal DNA variations. Our phylogenomic analyses led to two main conclusions. (1) Intra-species-level chloroplast genome variations are low in the three allotetraploids (2~7 SNPs), but rich and variable in each diploid species (7~193 SNPs). (2) Three allotetraploids maintain two 45SnrDNA types derived from both ancestral species with maternal dominance. Furthermore, this study sheds light on the maternal origin of the AC chloroplast genome. Overall, this study clarifies the genetic relationships of U's triangle species based on a comprehensive genomics approach and provides important genomic resources for correlative and evolutionary studies.

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. CROP SPECIES RECOGNITION AND DISCRIMINATION PADDY-RICE-GROWINGFIELDS FROM REAPED-FIELDS BY THE RADAR VEGETATION INDEX (RVI OF ALOS-2/PALSAR2

    Directory of Open Access Journals (Sweden)

    Y. Yamada

    2016-06-01

    Full Text Available The Japanese ALOS-2 satellite was launched on May 24th, 2014. It has the L-band SAR, PALSAR-2. Kim,Y. and van Zyl, J.J. proposed a kind of Radar Vegetation Index (RVI as RVI = 8 * σ0hv / (σ0hh + σ0vv + 2* σ0hv by L-band full-polarimetric radar data. Kim, Y. and Jackson, T.J., et al. applied the equation into rice and soybean by multi-frequency polarimetric scatterometer above 4.16 meters from the ground. Their report showed the L-band was the most promising wave length for estimating LAI and NDVI from RVI. The author tried to apply the analysis to the actual paddy field areas, both Inashiki region and Miyagi region in the eastern main island, “Honshu”, areas of Japan by ALOS-2/PALSAR-2 full-polarimetry data in the summer season, the main crop growing time, of 2015. Judging from conventional methods, it will be possible to discriminate paddy rice growing fields from reaped fields or the other crops growing fields by the PALSAR-2 data. But the RVI value is vaguely related to such land use or biomass at the present preliminary experiment. The continuous research by the additional PALSAR-2 full-polarimetry data should be desired.

  17. Homoeologous Recombination of the V1r1-V1r2 Gene Cluster of Pheromone Receptors in an Allotetraploid Lineage of Teleosts

    Directory of Open Access Journals (Sweden)

    Lei Zhong

    2017-11-01

    Full Text Available In contrast to other olfactory receptor families that exhibit frequent lineage-specific expansions, the vomeronasal type 1 receptor (V1R family exhibits a canonical six-member repertoire in teleosts. V1r1 and V1r2 are present in no more than one copy in all examined teleosts, including salmons, which are ancient polyploids, implying strict evolutionary constraints. However, recent polyploids have not been examined. Here, we identified a young allotetraploid lineage of weatherfishes and investigated their V1r1-V1r2 cluster. We found a novel pattern that the parental V1r1-V1r2 clusters had recombined in the tetraploid genome and that the recombinant was nearly fixed in the tetraploid population. Subsequent analyses suggested strong selective pressure, for both a new combination of paralogs and homogeneity among gene duplicates, acting on the V1r1-V1r2 pair.

  18. Rice methylmercury exposure and mitigation: a comprehensive review

    Science.gov (United States)

    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, price 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.

  19. Ethanol production from rice on radioactively contaminated field toward sustainable rice farming

    International Nuclear Information System (INIS)

    Yokoyama, Shinya; Izumi, Bintaro; Oki, Kazuo

    2011-01-01

    Radioactive species such as 137 Cs were discharged from Fukushima Daiichi Nuclear Power Plant which was severely damaged by the enormous earthquake and tsunami. Cropland has been radioactively contaminated by 137 Cs etc. and it seems impossible to plant rice due to the non-suitability for food. According to the reports, 137 Cs transferred into the rice from soil is less than 1% on the average. Therefore, it is expected that the concentration of 137 Cs in bioethanol will be well below the tentative restriction value even if bioethanol could be produced from the rice. It is proposed that the rice field should be filled with water to avoid the flow of runoff contaminated by radioactive cesium compounds because they are insoluble in aqueous phase and that bioethanol should be produced from the rice in order to maintain the multifunction of rice field and to continue the agriculture. If rice farming is halted and neglected, agricultural function of rice field as well as local community will be permanently destroyed. (author)

  20. Fungal diversity of rice straw for meju fermentation.

    Science.gov (United States)

    Kim, Dae-Ho; Kim, Seon-Hwa; Kwon, Soon-Wo; Lee, Jong-Kyu; Hong, Seung-Beom

    2013-12-01

    Rice straw is closely associated with meju fermentation and it is generally known that the rice straw provides meju with many kinds of microorganisms. In order to elucidate the origin of meju fungi, the fungal diversity of rice straw was examined. Rice straw was collected from 12 Jang factories where meju are produced, and were incubated under nine different conditions by altering the media (MEA, DRBC, and DG18), and temperature (15°C, 25°C, and 35°C). In total, 937 strains were isolated and identified as belonging to 39 genera and 103 species. Among these, Aspergillus, Cladosporium, Eurotium, Fusarium, and Penicillium were the dominant genera. Fusarium asiaticum (56.3%), Cladosporium cladosporioides (48.6%), Aspergillus tubingensis (37.5%), A. oryzae (31.9%), Eurotium repens (27.1%), and E. chevalieri (25.0%) were frequently isolated from the rice straw obtained from many factories. Twelve genera and 40 species of fungi that were isolated in the rice straw in this study were also isolated from meju. Specifically, A. oryzae, C. cladosporioides, E. chevalieri, E. repens, F. asiaticum, and Penicillium polonicum (11.8%), which are abundant species in meju, were also isolated frequently from rice straw. C. cladosporioides, F. asiaticum, and P. polonicum, which are abundant in the low temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at 15°C and 25°C, whereas A. oryzae, E. repens, and E. chevalieri, which are abundant in the high temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at 25°C and 35°C. This suggests that the mycobiota of rice straw has a large influence in the mycobiota of meju. The influence of fungi on the rice straw as feed and silage for livestock, and as plant pathogens for rice, are discussed as well.

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

    Directory of Open Access Journals (Sweden)

    Seonghee Lee

    Full Text Available The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus, which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH, suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta, not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing.

  2. Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

    Science.gov (United States)

    Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

    2011-01-01

    The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312

  3. Fungi and some mycotoxins contaminating rice ( Oryza Sativa ) in ...

    African Journals Online (AJOL)

    The major fungal genera contaminating rice were Aspergillus, Penicillium, Fusarium, Alternaria, Mucor, Rhizopus, Trichoderma, Curvularia, elminthosporium and Cladosporium. The most prevalent fungal species on rice were .Penicillium spp., A. flavus, A. parasiticus, A. niger, Mucor spp., Rhizopus spp. and Alternaria spp.

  4. Adapting weed management in rice to changing climates

    NARCIS (Netherlands)

    Rodenburg, J.; Meinke, H.B.

    2011-01-01

    This paper provides some of the scientific background on how projected environmental conditions could affect weeds and weed management in rice in Africa. Elevated CO2 levels may have positive effects on rice competitiveness with C4 weeds, but these are generally outnumbered by C3 species in weed

  5. Acetylated starch of Ofada rice as a sustained polymer in ...

    African Journals Online (AJOL)

    Objectives: To formulate and evaluate repaglinide microspheres using acetylated starch of the indigenous rice species Oryza glaberrima Steud (Ofada) as polymer. Materials and Methods: Ofada rice starch was acetylated with acetic anhydride in pyridine (DS 2.68) and characterized for morphology (Scanning electron ...

  6. Effect of transgenic Bacillus thuringiensis rice lines on mortality and feeding behavior of rice stem borers (Lepidoptera: Crambidae).

    Science.gov (United States)

    Chen, Hao; Zhang, Guoan; Zhang, Qifa; Lin, Yongjun

    2008-02-01

    Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future.

  7. Rice peasants and rice research in Colombia

    NARCIS (Netherlands)

    Spijkers, P.A.N.M.

    1983-01-01

    Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp

  8. Characterization of paralogous protein families in rice

    Directory of Open Access Journals (Sweden)

    Zhu Wei

    2008-02-01

    Full Text Available Abstract Background High gene numbers in plant genomes reflect polyploidy and major gene duplication events. Oryza sativa, cultivated rice, is a diploid monocotyledonous species with a ~390 Mb genome that has undergone segmental duplication of a substantial portion of its genome. This, coupled with other genetic events such as tandem duplications, has resulted in a substantial number of its genes, and resulting proteins, occurring in paralogous families. Results Using a computational pipeline that utilizes Pfam and novel protein domains, we characterized paralogous families in rice and compared these with paralogous families in the model dicotyledonous diploid species, Arabidopsis thaliana. Arabidopsis, which has undergone genome duplication as well, has a substantially smaller genome (~120 Mb and gene complement compared to rice. Overall, 53% and 68% of the non-transposable element-related rice and Arabidopsis proteins could be classified into paralogous protein families, respectively. Singleton and paralogous family genes differed substantially in their likelihood of encoding a protein of known or putative function; 26% and 66% of singleton genes compared to 73% and 96% of the paralogous family genes encode a known or putative protein in rice and Arabidopsis, respectively. Furthermore, a major skew in the distribution of specific gene function was observed; a total of 17 Gene Ontology categories in both rice and Arabidopsis were statistically significant in their differential distribution between paralogous family and singleton proteins. In contrast to mammalian organisms, we found that duplicated genes in rice and Arabidopsis tend to have more alternative splice forms. Using data from Massively Parallel Signature Sequencing, we show that a significant portion of the duplicated genes in rice show divergent expression although a correlation between sequence divergence and correlation of expression could be seen in very young genes. Conclusion

  9. Transgenic Bacillus thuringiensis (Bt rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    Directory of Open Access Journals (Sweden)

    Guangsheng Li

    Full Text Available Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems.

  10. Selection of Wild Plant Species from Organic Rice Field in Sumberngepoh Village in Malang as Attractant of Trichogramma spp. (Hymenoptera, Trichogrammatidae

    Directory of Open Access Journals (Sweden)

    Wahyu Kusumayanti Putri

    2014-09-01

    Full Text Available One of the actions in biological control is the use of parasitoid. Some wild plant species can attract those parasitoid. By the fact, the objective of this research are to select some of wild plant species attracting Trichogramma spp. These wild plant were belong to Asteraceae (Eupatorium odoratum, Bidens pilosa, Crassocephalum crepidioides and Mimosaceae (Parkia speciosa, Leucaena glauca, Mimosa pudica. Mass rearing of trichogramma spp. was prepared for those purpose. The selection were conducted by using four armed olfactometer. The percentage of the tested Trichogramma spp. attracted to the wild plant species was noted as well as their orientation duration to select the plant species. The difference of the mean of their orientation duration was analyzed statistically by T-Test. Both of plant familia can attract the parasitoid. This were the plant species that attracted Trichogramma spp. From the most attractive to the lowest one : B. pilosa 22 %, E. odoratum 18.6 %, M. pudica 18.2 %, C. crepidioides 13.8 %, P. speciosa 13.6 %, and L. glauca 13.6 %. For the orientation duration, this are the plant species that can attract the parasitoid from the fastest one to the slowest one : P. speciosa 45.5 seconds, C. crepidioides 46.2 seconds, L. glauca 49 seconds, E. odoratum 50.6 seconds , B. pilosa 53.4 seconds, and M. pudica 55.2 seconds. Keywords : Asteraceae, Mimosaceae, Trichogramma spp.

  11. Physicochemical and antioxidative properties of black, brown and red rice varieties of northern Thailand

    Directory of Open Access Journals (Sweden)

    Noppawat Pengkumsri

    2015-06-01

    Full Text Available Rice, the seed of Oryza species, is the major cereal crop in most of the developing countries. Nearly 95% of global rice production is done in Asian countries, and about half of the world’s population consumes it. Some speciality rices are not commonly consumed. Colored rice is one of such variety. In these varieties, high amounts of anthocyanin pigment are deposited in the rice coat to form its black (also known as purple, brown and red colors. Minimum studies are there to explain the properties of these rice varieties of Thailand. Thus, the current study was aimed to assess the physicochemical and antioxidative properties of three rice varieties (Chiang Mai Black rice, Mali Red rice and Suphanburi-1 Brown rice of different cultivars of northern Thailand. Rice bran extracts of these three cultivars were prepared with different solvents (polar and non-polar for the evaluation of total phytochemical content and anti-oxidant free-radical-scavenging properties. Chiang Mai Black rice contained higher concentration of phenolic acid, flavonoids, and anthocyanins (Cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin chloride. Chiang Mai Black rice is richer in free-radical-scavenging compounds and activities than the other tested varieties. Polar extractions of rice bran are high in anti-oxidative compounds and activities than non-polar extractions.

  12. ANALYSIS ON THE DYNAMICS OF SPATIAL DISTRIBUTION PATTERN OF MIXED SPIDER POPULATION IN RICE FIELD

    Institute of Scientific and Technical Information of China (English)

    ZhiWang; Zhe-mingYuan; Da-xiangSong; Ming-shengZhu

    2004-01-01

    The results make it clear that there are total 11 families, 29 genera and 43 species of spiders in the rice field of Dong Fang Hong Farm. Among them, there are 8 families, 19 genera and 28 species in the early rice field, and 10 families, 27 genera and 36 species in the late rice field. The spatial distribution pattern of mixed spider populations in rice fields was different during different development stages of rice plant. During the prophase, metaphase and anaphase of early rice plant development, the spatial distribution pattern of mixed spider populations was aggregative, random and aggregative respectively. During the prophase, metaphase and anaphase of late rice plant development, the spatial distribution pattern was uniform, aggregative and uniform respectively.

  13. Bt rice in China - focusing the nontarget risk assessment.

    Science.gov (United States)

    Li, Yunhe; Zhang, Qingling; Liu, Qingsong; Meissle, Michael; Yang, Yan; Wang, Yanan; Hua, Hongxia; Chen, Xiuping; Peng, Yufa; Romeis, Jörg

    2017-10-01

    Bt rice can control yield losses caused by lepidopteran pests but may also harm nontarget species and reduce important ecosystem services. A comprehensive data set on herbivores, natural enemies, and their interactions in Chinese rice fields was compiled. This together with an analysis of the Cry protein content in arthropods collected from Bt rice in China indicated which nontarget species are most exposed to the insecticidal protein and should be the focus of regulatory risk assessment. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  14. Arsenic biotransformation and volatilization in transgenic rice

    Science.gov (United States)

    Meng, Xiang-Yan; Qin, Jie; Wang, Li-Hong; Duan, Gui-Lan; Sun, Guo-Xin; Wu, Hui-Lan; Chu, Cheng-Cai; Ling, Hong-Qing; Rosen, Barry P.; Zhu, Yong-Guan

    2011-01-01

    Summary Biotransformation of arsenic includes oxidation, reduction, methylation and conversion to more complex organic arsenicals. Members of the class of arsenite [As(III)] S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di- and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa L.) cultivar Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). Both monomethylarsenate [MAs(V)] and dimethylarsenate [DMAs(V)] were detected in the root and shoot of transgenic rice. After 12-d exposure to As(III), the transgenic rice gave off 10-fold more volatile arsenicals. The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, providing a potential stratagem for phytoremediation theoretically. PMID:21517874

  15. The deposition of radioiodine onto rice plant from atmosphere

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Muramatsu, Yasuyuki; Yoshida, Satoshi; Sumiya, Misako; Ohmomo, Yoichiro.

    1994-01-01

    Radiation dose estimations are usually made with the aid of assessment models in which model parameters such as the transfer factors of radionuclides from one environmental compartment to another are involved. In simple models the parameters are often described as the concentration ratio of a radionuclide between two compartments, when the system is under equilibrium condition. In this paper, the authors introduce the values of the parameters of radioiodine obtained by tracer experiments. Laboratory experiments on the transfer parameters of radionuclides from the atmosphere to rice plant were carried out in the atmosphere-to-crops system (deposition pathway). It is known that the typical chemical species of gaseous iodine in the atmosphere are elemental iodine (I 2 ) and methyliodide (CH 3 I). The deposition characteristics of both chemical species of gaseous iodine to rice grains were obtained. Mass normalized deposition velocity (V D ) and grain number normalized deposition velocity (V S ) of gaseous elemental iodine (I 2 ) and also methyliodide (CH 3 I) on unhulled rice were measured. Both V D and V S of methyliodide were about one percent of those of elemental iodine. Distribution pattern of methyliodide between unhulled rice and brown rice was significantly lower than that of elemental one. For wet deposition, we investigated the retention of radioiodines (iodide [I - ] and iodate [IO 3 - ] on rice grains and their translocation from the surface of the grains to brown rice. Though the ears were dipped into the solution containing 125 I - or 125 IO 3 - more than 15 min., both iodine species in the solutions were hardly taken up to the rice grains. The transfer rates of iodide and iodate, which are defined as 'the amount of the iodine in brown rice' divided by 'the amount of iodide in unhulled rice' were about 0.015 and 0.04, respectively. The rates were not changed with time after the radioiodine application. (author)

  16. Malaysian weedy rice shows its true stripes: wild Oryza and elite rice cultivars shape agricultural weed evolution in Southeast Asia.

    Science.gov (United States)

    Song, Beng-Kah; Chuah, Tse-Seng; Tam, Sheh May; Olsen, Kenneth M

    2014-10-01

    Weedy rice is a close relative of domesticated rice (Oryza sativa) that competes aggressively with the crop and limits rice productivity worldwide. Most genetic studies of weedy rice have focused on populations in regions where no reproductively compatible wild Oryza species occur (North America, Europe and northern Asia). Here, we examined the population genetics of weedy rice in Malaysia, where wild rice (O. rufipogon) can be found growing in close proximity to cultivated and weedy rice. Using 375 accessions and a combined analysis of 24 neutral SSR loci and two rice domestication genes (sh4, controlling seed shattering, and Bh4, controlling hull colour), we addressed the following questions: (i) What is the relationship of Malaysian weedy rice to domesticated and wild rice, and to weedy rice strains in the USA? (ii) To what extent does the presence of O. rufipogon influence the genetic and phenotypic diversity of Malaysian weeds? (iii) What do the distributions of sh4 and Bh4 alleles and associated phenotypes reveal about the origin and contemporary evolution of Malaysian weedy rice? Our results reveal the following: independent evolutionary origins for Malaysian weeds and US strains, despite their very close phenotypic resemblance; wild-to-weed gene flow in Malaysian weed populations, including apparent adaptive introgression of seed-shattering alleles; and a prominent role for modern Malaysian cultivars in the origin and recent proliferation of Malaysian weeds. These findings suggest that the genetic complexity and adaptability of weedy crop relatives can be profoundly influenced by proximity to reproductively compatible wild and domesticated populations. © 2014 John Wiley & Sons Ltd.

  17. A comparison of spider communities in Bt and non-Bt rice fields.

    Science.gov (United States)

    Lee, Sue Yeon; Kim, Seung Tae; Jung, Jong Kook; Lee, Joon-Ho

    2014-06-01

    To assess the potential adverse effects of a Bt rice line (Japonica rice cultivar, Nakdong) expressing a synthetic cry1Ac1 gene, C7-1-9-1-B, which was highly active against all larval stages of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), we investigated the community structure of spiders in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008 in Chungcheongnam-do, Korea. Spiders were surveyed with a sweep net and suction device. Suction sampling captured more spiders, measured in terms of species level and abundance, than sweeping. Araneidae and Thomisidae were captured more by sweeping, and certain species were captured only by sweeping. These findings show that both suction and sweep sampling methods should be used because these methods are most likely complementary. In total, 29 species in 23 genera and nine families were identified from the 4,937 spiders collected, and both Bt and non-Bt rice fields showed a typical Korean spider assemblage. The temporal patterns of spider species richness and spider abundance were very similar between Bt and non-Bt rice, although significant differences in species richness were observed on a few occasions. Overall, spider community structure, including diversity, the dominant species, and abundance did not differ between Bt and non-Bt rice. The results of the study indicated that the transgenic Cry1Ac rice lines tested in this study had no adverse effects on the spider community structure of the rice fields.

  18. Arsenic accumulation and phosphorus status in two rice (Oryza sativa L.) cultivars surveyed from fields in South China

    International Nuclear Information System (INIS)

    Lu Ying; Dong, Fei; Deacon, Claire; Chen Huojun; Raab, Andrea; Meharg, Andrew A.

    2010-01-01

    The consumption of paddy rice (Oryza sativa L.) is a major inorganic arsenic exposure pathway in S.E. Asia. A multi-location survey was undertaken in Guangdong Province, South China to assess arsenic accumulation and speciation in 2 rice cultivars, one an Indica and the other a hybrid Indica. The results showed that arsenic concentrations in rice tissue increased in the order grain < husk < straw < root. Rice grain arsenic content of 2 rice cultivars was significant different and correlated with phosphorus concentration and molar ratio of P/As in shoot, being higher for the Indica cultivar than for the hybrid Indica, which suggests altering shoot phosphorus status as a promising route for breeding rice cultivars with reduced grain arsenic. Speciation of grain arsenic, performed using HPLC-ICP-MS, identified inorganic arsenic as the dominant arsenic species present in the rice grain. - Altering rice shoot phosphorus status is a promising route for breeding rice cultivars with reduced grain arsenic.

  19. Rice (Oryza) hemoglobins

    Science.gov (United States)

    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...

  20. Responses of endogenous proline in rice seedlings under chromium exposure

    Directory of Open Access Journals (Sweden)

    X.Z. Yu

    2016-12-01

    Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p

  1. Chromosome studies of european cyprinid fishes: Cross-species painting reveals natural allotetraploid origin of a carassius female with 206 chromosomes

    Czech Academy of Sciences Publication Activity Database

    Knytl, M.; Kalous, L.; Symonová, Radka; Rylková, K.; Ráb, Petr

    2013-01-01

    Roč. 139, č. 4 (2013), s. 276-283 ISSN 1424-8581 R&D Projects: GA ČR(CZ) GPP506/11/P596 Institutional support: RVO:67985904 Keywords : fish cytogenetics * genome addition * GISH Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.905, year: 2013

  2. Selective determination of four arsenic species in rice and water samples by modified graphite electrode-based electrolytic hydride generation coupled with atomic fluorescence spectrometry.

    Science.gov (United States)

    Yang, Xin-An; Lu, Xiao-Ping; Liu, Lin; Chi, Miao-Bin; Hu, Hui-Hui; Zhang, Wang-Bing

    2016-10-01

    This work describes a novel non-chromatographic approach for the accurate and selective determining As species by modified graphite electrode-based electrolytic hydride generation (EHG) for sample introduction coupled with atomic fluorescence spectrometry (AFS) detection. Two kinds of sulfydryl-containing modifiers, l-cysteine (Cys) and glutathione (GSH), are used to modify cathode. The EHG performance of As has been changed greatly at the modified cathode, which has never been reported. Arsenite [As(III)] on the GSH modified graphite electrode (GSH/GE)-based EHG can be selectively and quantitatively converted to AsH3 at applied current of 0.4A. As(III) and arsenate [As(V)] on the Cys modified graphite electrode (Cys/GE) EHG can be selectively and efficiently converted to arsine at applied current of 0.6A, whereas monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) do not form any or only less volatile hydrides under this condition. By changing the analytical conditions, we also have achieved the analysis of total As (tAs) and DMA. Under the optimal condition, the detection limits (3s) of As(III), iAs and tAs in aqueous solutions are 0.25μgL(-1), 0.22μgL(-1) and 0.10μgL(-1), respectively. The accuracy of the method is verified through the analysis of standard reference materials (SRM 1568a). Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Genome-wide patterns of nucleotide polymorphism in domesticated rice

    DEFF Research Database (Denmark)

    Caicedo, Ana L; Williamson, Scott H; Hernandez, Ryan D

    2007-01-01

    Domesticated Asian rice (Oryza sativa) is one of the oldest domesticated crop species in the world, having fed more people than any other plant in human history. We report the patterns of DNA sequence variation in rice and its wild ancestor, O. rufipogon, across 111 randomly chosen gene fragments......, and use these to infer the evolutionary dynamics that led to the origins of rice. There is a genome-wide excess of high-frequency derived single nucleotide polymorphisms (SNPs) in O. sativa varieties, a pattern that has not been reported for other crop species. We developed several alternative models...... to explain contemporary patterns of polymorphisms in rice, including a (i) selectively neutral population bottleneck model, (ii) bottleneck plus migration model, (iii) multiple selective sweeps model, and (iv) bottleneck plus selective sweeps model. We find that a simple bottleneck model, which has been...

  4. The Evolutionary Basis of Naturally Diverse Rice Leaves Anatomy.

    Directory of Open Access Journals (Sweden)

    Jolly Chatterjee

    Full Text Available Rice contains genetically and ecologically diverse wild and cultivated species that show a wide variation in plant and leaf architecture. A systematic characterization of leaf anatomy is essential in understanding the dynamics behind such diversity. Therefore, leaf anatomies of 24 Oryza species spanning 11 genetically diverse rice genomes were studied in both lateral and longitudinal directions and possible evolutionary trends were examined. A significant inter-species variation in mesophyll cells, bundle sheath cells, and vein structure was observed, suggesting precise genetic control over these major rice leaf anatomical traits. Cellular dimensions, measured along three growth axes, were further combined proportionately to construct three-dimensional (3D leaf anatomy models to compare the relative size and orientation of the major cell types present in a fully expanded leaf. A reconstruction of the ancestral leaf state revealed that the following are the major characteristics of recently evolved rice species: fewer veins, larger and laterally elongated mesophyll cells, with an increase in total mesophyll area and in bundle sheath cell number. A huge diversity in leaf anatomy within wild and domesticated rice species has been portrayed in this study, on an evolutionary context, predicting a two-pronged evolutionary pathway leading to the 'sativa leaf type' that we see today in domesticated species.

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

    Science.gov (United States)

    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.

  6. The Rice Mitochondria Proteome and its Response During Development and to the Environment

    Directory of Open Access Journals (Sweden)

    Shaobai eHuang

    2013-02-01

    Full Text Available Rice (Oryza sativa L. is both a major crop species and the key model grass for molecular and physiological research. Mitochondria are important in rice, as in all crops, as the main source of ATP for cell maintenance and growth. However, the practical significance of understanding the function of mitochondria in rice is increased by the widespread farming practice of using hybrids to boost rice production. This relies on cytoplasmic male-sterile (CMS lines with abortive pollen caused by dysfunctional mitochondria. We provide an overview of what is known about the mitochondrial proteome of rice seedlings. To date, more than 320 proteins have been identified in purified rice mitochondria using mass spectrometry. The insights from this work include a broad understanding of the major subunits of mitochondrial respiratory complexes and TCA cycle enzymes, carbon and nitrogen metabolism enzymes as well as details of the supporting machinery for biogenesis and the subset of stress-responsive mitochondrial proteins. Many proteins with unknown functions have also been found in rice mitochondria. Proteomic analysis has also revealed the features of rice mitochondrial protein presequences required for mitochondrial targeting, as well as cleavage site features for processing of precursors after import. Changes in the abundance of rice mitochondrial proteins in response to different stresses, especially anoxia and light, are summarized. Future research on quantitative analysis of the rice mitochondrial proteomes at the spatial and developmental level, its response to environmental stresses and recent advances in understanding of basis of rice CMS systems are highlighted.

  7. Candida septic arthritis with rice body formation: A case report and review of literature

    International Nuclear Information System (INIS)

    Jeong, Yu Mi; Cho, Hyun Yee; Lee, Sheen Woo; Hwang, Yun Mi; Kim, Young Kyu

    2013-01-01

    Rice body formation in a joint or bursa is a rare condition, and is usually associated with rheumatoid arthritis or tuberculous arthritis. Here we describe a case of multiple rice body formation in a shoulder joint and in adjacent bursae, which was confirmed to be due to septic arthritis by Candida species. To the best of our knowledge, rice body formation in Candida septic arthritis in an immune-competent patient has not been previously reported.

  8. The orthopterans of the rice agroecosystem in western Lomellina (Lombardy, Italy)

    OpenAIRE

    Giuliano, Davide; Bogliani, Giuseppe

    2018-01-01

    Rice fields represent a valuable surrogate habitat for many wetland species, playing an important role for biodiversity conservation in human-managed landscapes. Despite the fact that several taxonomic groups have been thoroughly investigated in this agroecosystem, little is known about the orthopteran fauna which lives in and around rice paddies, especially in Europe. In this paper, we provide a first description of the orthopteran assemblages hosted in the rice agroecosystems of northern It...

  9. Candida septic arthritis with rice body formation: A case report and review of literature

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yu Mi; Cho, Hyun Yee; Lee, Sheen Woo; Hwang, Yun Mi; Kim, Young Kyu [Gachon University, Gil Hospital, Incheon (Korea, Republic of)

    2013-06-15

    Rice body formation in a joint or bursa is a rare condition, and is usually associated with rheumatoid arthritis or tuberculous arthritis. Here we describe a case of multiple rice body formation in a shoulder joint and in adjacent bursae, which was confirmed to be due to septic arthritis by Candida species. To the best of our knowledge, rice body formation in Candida septic arthritis in an immune-competent patient has not been previously reported.

  10. Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice

    International Nuclear Information System (INIS)

    Sumiya, Misako; Uchida, Shigeo; Muramatsu, Yasuyuki; Ohmomo, Yoichiro; Yamaguchi, Shuho; Obata, Hitoshi.

    1987-01-01

    Experiments were carried out in order to obtain information required for establishing transfer coefficients of gaseous iodine (I 2 ) to rough rice, brown rice and polished rice. The gaseous iodine deposited on young rice plants before the heading period was scarcely found in the rough rice harvested at the full ripe stage. The biological half life of iodine in hull, however, was much slower than that in leaves of 14 days. The translocation of iodine from leaves and stalks to rough rice was not clearly recognized. Therefore, it was deduced that iodine found in brown rice mainly should originate from that deposited on the hull. The distribution ratios of iodine between rough rice and brown rice, and between brown rice and polished rice were 100:4 and 100:30 on 100 grains basis, respectively. If average normalized deposition velocity (V d(m) ) or derived deposition velocity (V s ) are given, the transfer coefficients of gaseous iodine to rough rice (TF r ), brown rice (TF b ) and polished rice (TF p ) could be calculated. (author)

  11. Sequencing of Australian wild rice genomes reveals ancestral relationships with domesticated rice.

    Science.gov (United States)

    Brozynska, Marta; Copetti, Dario; Furtado, Agnelo; Wing, Rod A; Crayn, Darren; Fox, Glen; Ishikawa, Ryuji; Henry, Robert J

    2017-06-01

    The related A genome species of the Oryza genus are the effective gene pool for rice. Here, we report draft genomes for two Australian wild A genome taxa: O. rufipogon-like population, referred to as Taxon A, and O. meridionalis-like population, referred to as Taxon B. These two taxa were sequenced and assembled by integration of short- and long-read next-generation sequencing (NGS) data to create a genomic platform for a wider rice gene pool. Here, we report that, despite the distinct chloroplast genome, the nuclear genome of the Australian Taxon A has a sequence that is much closer to that of domesticated rice (O. sativa) than to the other Australian wild populations. Analysis of 4643 genes in the A genome clade showed that the Australian annual, O. meridionalis, and related perennial taxa have the most divergent (around 3 million years) genome sequences relative to domesticated rice. A test for admixture showed possible introgression into the Australian Taxon A (diverged around 1.6 million years ago) especially from the wild indica/O. nivara clade in Asia. These results demonstrate that northern Australia may be the centre of diversity of the A genome Oryza and suggest the possibility that this might also be the centre of origin of this group and represent an important resource for rice improvement. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  12. Prevalence of Rice Yellow Mottle Virus (RYMV) on Rice Plants ...

    African Journals Online (AJOL)

    Abstract. Incidence of Rice yellow mottle virus (RYMV) on rice plants (ofada) grown in two local government areas (LGAs) of Ogun State had been evaluated during a two year field survey. Six month old rice plants were observed for symptom expression and leaf samples collected for serological indexing. Of the 60 leaf ...

  13. Structure, Function, and Evolution of Rice Centromeres

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jiming

    2010-02-04

    The centromere is the most characteristic landmark of eukaryotic chromosomes. Centromeres function as the site for kinetochore assembly and spindle attachment, allowing for the faithful pairing and segregation of sister chromatids during cell division. Characterization of centromeric DNA is not only essential to understand the structure and organization of plant genomes, but it is also a critical step in the development of plant artificial chromosomes. The centromeres of most model eukaryotic species, consist predominantly of long arrays of satellite DNA. Determining the precise DNA boundary of a centromere has proven to be a difficult task in multicellular eukaryotes. We have successfully cloned and sequenced the centromere of rice chromosome 8 (Cen8), representing the first fully sequenced centromere from any multicellular eukaryotes. The functional core of Cen8 spans ~800 kb of DNA, which was determined by chromatin immunoprecipitation (ChIP) using an antibody against the rice centromere-specific H3 histone. We discovered 16 actively transcribed genes distributed throughout the Cen8 region. In addition to Cen8, we have characterized eight additional rice centromeres using the next generation sequencing technology. We discovered four subfamilies of the CRR retrotransposon that is highly enriched in rice centromeres. CRR elements are constitutively transcribed and different CRR subfamilies are differentially processed by RNAi. These results suggest that different CRR subfamilies may play different roles in the RNAi-mediated pathway for formation and maintenance of centromeric chromatin.

  14. Genome Sequences of Oryza Species

    KAUST Repository

    Kumagai, Masahiko; Tanaka, Tsuyoshi; Ohyanagi, Hajime; Hsing, Yue-Ie C.; Itoh, Takeshi

    2018-01-01

    This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

  15. Genome Sequences of Oryza Species

    KAUST Repository

    Kumagai, Masahiko

    2018-02-14

    This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

  16. Heat-assisted aqueous extraction of rice flour for arsenic speciation analysis.

    Science.gov (United States)

    Narukawa, Tomohiro; Chiba, Koichi

    2010-07-28

    A versatile heat-assisted pretreatment aqueous extraction method for the analysis of arsenic species in rice was developed. Rice flour certified reference materials NIST SRM1568a and NMIJ CRM 7503-a and a flour made from polished rice were used as samples, and HPLC-ICP-MS was employed for the determination of arsenic species. Arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) were detected in NIST SRM, and As(III), As(V) and DMAA were found in NMIJ CRM and the prepared polished rice flour. The sums of the concentrations of all species in each rice flour sample were 97-102% of the total arsenic concentration in each sample.

  17. Genomic patterns of nucleotide diversity in divergent populations of U.S. weedy rice

    Directory of Open Access Journals (Sweden)

    Olsen Kenneth M

    2010-06-01

    Full Text Available Abstract Background Weedy rice (red rice, a conspecific weed of cultivated rice (Oryza sativa L., is a significant problem throughout the world and an emerging threat in regions where it was previously absent. Despite belonging to the same species complex as domesticated rice and its wild relatives, the evolutionary origins of weedy rice remain unclear. We use genome-wide patterns of single nucleotide polymorphism (SNP variation in a broad geographic sample of weedy, domesticated, and wild Oryza samples to infer the origin and demographic processes influencing U.S. weedy rice evolution. Results We find greater population structure than has been previously reported for U.S. weedy rice, and that the multiple, genetically divergent populations have separate origins. The two main U.S. weedy rice populations share genetic backgrounds with cultivated O. sativa varietal groups not grown commercially in the U.S., suggesting weed origins from domesticated ancestors. Hybridization between weedy groups and between weedy rice and local crops has also led to the evolution of distinct U.S. weedy rice populations. Demographic simulations indicate differences among the main weedy groups in the impact of bottlenecks on their establishment in the U.S., and in the timing of divergence from their cultivated relatives. Conclusions Unlike prior research, we did not find unambiguous evidence for U.S. weedy rice originating via hybridization between cultivated and wild Oryza species. Our results demonstrate the potential for weedy life-histories to evolve directly from within domesticated lineages. The diverse origins of U.S. weedy rice populations demonstrate the multiplicity of evolutionary forces that can influence the emergence of weeds from a single species complex.

  18. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Science.gov (United States)

    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 Rice...

  19. Symbiont-mediated adaptation by planthoppers and leafhoppers to resistant rice varieties

    NARCIS (Netherlands)

    Ferrater, J.B.; Jong, de P.W.; Dicke, M.; Chen, Y.H.; Horgan, F.G.

    2013-01-01

    For over 50 years, host plant resistance has been the principal focus of public research to reduce planthopper and leafhopper damage to rice in Asia. Several resistance genes have been identified from native varieties and wild rice species, and some of these have been incorporated into high-yielding

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

    Science.gov (United States)

    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...

  1. Extraction of rice bran oil from local rice husk

    International Nuclear Information System (INIS)

    Anwar, J.; Zaman, W.; Salman, M.; Jabeen, N.

    2006-01-01

    Rice Bran Oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In the present work, extraction of rice bran oil from different samples of rice husk collected from local rice shellers by solvent extraction method has been studied. Experiments were conducted using a soxhelt apparatus, to extract rice bran oil using hexane, petroleum ether, ethanol and methanol as the solvents and the yields obtained under different conditions were compared. Batch extraction tests showed that the rate of extraction decreases with time and the solution approaches saturation at an exponential rate. (author)

  2. Gasification of rice husks

    Energy Technology Data Exchange (ETDEWEB)

    Marzetti, P. (ENEA, Rome (Italy). Dipt. Fonti Alternative e Risparmio Energetico)

    The paper outlines the thermochemical processes and equipment involved in the gasification of rice husks. An assessment is made of the feasibility (availability, technology requirements, economics of production and marketing) of this renewable energy source. Results, reported here in tabular form, of experimental trials at an Italian pilot plant (producing, with the use of 165 kg/h of rice husks, 350,000 kcal/h of gas with a conversion yield of 70%) indicated good feasibility. More research is required to improve the combustion qualities of the final product.

  3. Ecological mechanisms underlying the sustainability of the agricultural heritage rice-fish coculture system.

    Science.gov (United States)

    Xie, Jian; Hu, Liangliang; Tang, Jianjun; Wu, Xue; Li, Nana; Yuan, Yongge; Yang, Haishui; Zhang, Jiaen; Luo, Shiming; Chen, Xin

    2011-12-13

    For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice-fish coculture (RF), which has been designated a "globally important agricultural heritage system," has been maintained for over 1,200 y in south China. A field survey demonstrated that although rice yield and rice-yield stability are similar in RF and rice monoculture (RM), RF requires 68% less pesticide and 24% less chemical fertilizer than RM. A field experiment confirmed this result. We documented that a mutually beneficial relationship between rice and fish develops in RF: Fish reduce rice pests and rice favors fish by moderating the water environment. This positive relationship between rice and fish reduces the need for pesticides in RF. Our results also indicate a complementary use of nitrogen (N) between rice and fish in RF, resulting in low N fertilizer application and low N release into the environment. These findings provide unique insights into how positive interactions and complementary use of resource between species generate emergent ecosystem properties and how modern agricultural systems might be improved by exploiting synergies between species.

  4. Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.

    Science.gov (United States)

    Naito, Risa; Yamasaki, Michimasa; Lmanishi, Ayumi; Natuhara, Yosihiro; Morimoto, Yukihiro

    2012-09-01

    In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species.

  5. The New Transgenic cry1Ab/vip3H Rice Poses No Unexpected Ecological Risks to Arthropod Communities in Rice Agroecosystems.

    Science.gov (United States)

    Lu, Zengbin; Dang, Cong; Han, Naishun; Shen, Zhicheng; Peng, Yufa; Stanley, David; Ye, Gongyin

    2016-04-01

    The ecological risks to nontarget organisms should be rigorously assessed before Bt crops are released. Here, the impacts of a new Cry1Ab/Vip3H rice line on arthropod communities in rice agroecosystems were evaluated across 3 yr. Arthropods collected via vacuum were sorted into five guilds. The abundance and proportion of each guild as well as community-level parameters were determined in Cry1Ab/Vip3H and control rice fields. Changes in arthropod species assemblage over sampling dates were investigated by principal response curves (PRCs). Cry1Ab/Vip3H rice did not exert significant impacts on the seasonal density and proportion of each guild, except parasitoids. Detritivore seasonal density, but not its relative abundance, was significantly affected by Cry1Ab/Vip3H rice. Four community indices (species richness S, Shannon-Wiener index H', Simpson index D, and evenness index J') were similar between rice types. PRCs revealed a slight community difference between rice types in the past two tested years, with rice types accounting for 1.0-3.5% of the variance among arthropod communities. However, sampling dates explain 32.1-67.6% for these community differences. Of the 46 taxa with higher species weights, 26.1% of the taxa were significantly different, including seven taxa with higher abundance and five with lower density in Cry1Ab/Vip3H rice fields. These differences may be attributed to change in abundance of prey or hosts but not to direct effects of Bt proteins. We infer that this new Cry1Ab/Vip3H rice line poses no unintended ecological risks to the arthropod community. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Interspecific variation of total seed protein in wild rice germplasm using SDS-Page

    International Nuclear Information System (INIS)

    Shah, S.M.A.; Hidayat-ur-Rahman; Abbasi, F.M.; Ashiq, M.; Rabbani, A.M.; Khan, I.A.; Shinwari, Z.K.; Shah, Z.

    2011-01-01

    Variation in seed protein of 14 wild rice species (Oryza spp.) along with cultivated rice species (O. sativa) was studied using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to assess genetic diversity in the rice germplasm. SDS bands were scored as present (1) or absent (0) for protein sample of each genotype. On the basis of cluster analysis, four clusters were identified at a similarity level of 0.85. O. nivara, O. rufipogon and O. sativa with AA genomes constituted the first cluster. The second cluster comprised O. punctata of BB genome and wild rice species of CC genome i.e., O. rhizomatis and O. officinalis. However, it also contained O. barthii and O. glumaepatula of AA genome. O. australiensis with EE genome, and O. latifolia, O. alta and O. grandiglumis having CCDD genomes comprised the third cluster. The fourth cluster consisted of wild rice species, O. brachyantha with EE genome along with two other wild rice species, O. longistaminata and O. meridionalis of AA genome. Overall, on the basis of total seed protein, the grouping pattern of rice genotypes was mostly compatible with their genome status. The results of the present work depicted considerable interspecific genetic variation in the investigated germplasm for total seed protein. Moreover, the results obtained in this study also suggest that analysis of seed protein can also provide a better understanding of genetic affinity of the germplasm. (author)

  7. Weed populations and their buried seeds in rice fields of the MUDA area

    International Nuclear Information System (INIS)

    Ismail Sahid; Noor Faezah Zainuddin; Ho Nai Kin

    2002-01-01

    A total of 25 weed species belonging to 15 families were found in rice fields near Kampung Tandop, in the Muda Irrigation Scheme, Kedah, Malaysia. The dominant weeds in dry-seeded rice were Utricularia aurea Lour., Fimbristylis miliacea (L.) vahl., Echinochloa crusgalli (L.) Beauv., Monochoria vaginalis (Burm. Q Presl. and Najas graminea (Del.) Redl. In wet-seeded rice, the dominant species were N. graminea, Lemna minor L., Sphenoclea zeylanica Gaertn., U. aured, and Sagittaria guayanensis H. B. K., while in volunteer seedling rice fields, the dominant species were Echinochloa colonum (L.) Link., Fimbristylis alboviridis C. B. Clarke, E miliacea, Cyperus babakan Steud. and Fuirena umbellata Rottb. Dry-seeded rice fields contained the highest number of weed seeds (930 910/m 2 in the top 15 cm of soil); volunteer seedling rice fields contained 793.162/m 2 and wet-seeded rice fields 712 228/m 2 . In general, the seed numbers declined with increasing soil depth. At 1015 cm depth, seeds of U aurea and S. zeylanica were the most abundant in dry and wet-seeded rice fields, whilst seeds of Scirpusjuncoides Roxb. and E miliacea were most abundant in volunteer seedling fields. (Author)

  8. Diseases of wild rice

    Science.gov (United States)

    Diseases are much more pronounced in cultivated wild rice than in natural stands, most likely due to the narrower genetic base of the populations, plant stress due to high planting density and floodwater removal prior to harvest, and high relative humidity in the plant canopy. Yield losses occur as ...

  9. Promising rice mutants

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1988-01-01

    Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

  10. Antifungal activity of Leuconostoc citreum and Weissella confusa in rice cakes.

    Science.gov (United States)

    Baek, Eunjong; Kim, Hyojin; Choi, Hyejung; Yoon, Sun; Kim, Jeongho

    2012-10-01

    The antifungal activity of organic acids greatly improves the shelf life of bread and bakery products. However, little is known about the effect of lactic acid fermentation on fungal contamination in rice cakes. Here, we show that lactic acid fermentation in rice dough can greatly retard the growth of three fungal species when present in rice cakes, namely Cladosporium sp. YS1, Neurospora sp. YS3, and Penicillium crustosum YS2. The antifungal activity of the lactic acid bacteria against these fungi was much better than that of 0.3% calcium propionate. We found that organic acids including lactic and acetic acid, which are byproducts of lactic fermentation or can be artificially added, were the main antifungal substances. We also found that some Leuconostoc citreum and Weissella confusa strains could be good starter species for rice dough fermentation. These results imply that these lactic acid bacteria can be applicable to improve the preservation of rice cakes.

  11. Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

    Science.gov (United States)

    Kukusamude, C.; Kongsri, S.

    2017-10-01

    We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sungyod rice). Thai jasmine rice and Sungyod rice were cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sungyod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali 105) was cultivated from Thung Kula Rong Hai area, whereas Sungyod rice was cultivated from Phathalung province. Hypothesis testing of difference of each isotope between Thai jasmine rice and Sungyod rice was also studied. The study was the feasibility test whether the light stable isotopes can be the variables to identify Thai jasmine rice and Sungyod rice. The result shows that there was difference in the isotope patterns of Thai jasmine rice and Sungyod rice. Our results may provide the useful information in term of stable isotope profiles of Thai rice.

  12. Radiation disinfestation of Basmati rice

    International Nuclear Information System (INIS)

    Rao, V.S.; Gholap, A.S.; Adhikari, H.R.; Nair, P.M.

    1994-01-01

    Effect of low dose γ-radiation on prepackaged Basmati rice was studied in order to achieve disinfestation of rice. Basmati rice procured from local market was repacked in 1 kg pouches made from high density polyethylene (HDP) and biaxially oriented polypropylene: low density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25-1.0 kGy. Within one month of storage at room temperature, unirradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted due to irradiation in the functional properties of rice such as swelling index and water absorption and in total volatile components responsible for flavour of Basmati rice. In organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses at present due to infestation. (author). 24 refs., 5 tabs., 1 fig

  13. Southern rice black-streaked dwarf virus: a white-backed planthopper transmitted fijivirus threadening rice production in Asia

    Directory of Open Access Journals (Sweden)

    Guohui eZhou

    2013-09-01

    Full Text Available Southern rice black-streaked dwarf virus (SRBSDV, a nonenveloped icosahedral virus with a genome of 10 double-stranded RNA segments, is a novel species in the genus Fijivirus (family Reoviridae first recognized in 2008. Rice plants infected with this virus exhibit symptoms similar to those caused by Rice black-streaked dwarf virus. Since 2009, the virus has rapidly spread and caused serious rice losses in East and Southeast Asia. Significant progress has been made in recent years in understanding this disease, especially about the functions of the viral genes, rice–virus–insect interactions, and epidemiology and control measures. The virus can be efficiently transmitted by the white-backed planthopper (WBPH, Sogatella furcifera in a persistent circulative propagative manner but cannot be transmitted by the brown planthopper (Nilaparvata lugens and small brown planthopper (Laodelphax striatellus. Rice, maize, Chinese sorghum (Coix lacryma-jobi and other grass weeds can be infected via WBPH. However, only rice plays a major role in the virus infection cycle because of the vector's preference. In Southeast Asia, WBPH is a long-distance migratory rice pest. The disease cycle can be described as follows: SRBSDV and its WBPH vector overwinter in warm tropical or sub-tropical areas; viruliferous WBPH adults carry the virus from south to north via long-distance migration in early spring, transmit the virus to rice seedlings in the newly colonized areas, and lay eggs on the infected seedlings; the next generation of WBPHs propagate on infected seedlings, become viruliferous, disperse, and cause new disease outbreaks. Several molecular and serological methods have been developed to detect SRBSDV in plant tissues and individual insects. Control measures based on protection from WBPH, including seedbed coverage, chemical seed treatments, and chemical spraying of seedlings, have proven effective in China.

  14. Mercury flow through an Asian rice-based food web

    International Nuclear Information System (INIS)

    Abeysinghe, Kasun S.; Qiu, Guangle; Goodale, Eben; Anderson, Christopher W.N.; Bishop, Kevin; Evers, David C.; Goodale, Morgan W.; Hintelmann, Holger; Liu, Shengjie

    2017-01-01

    Mercury (Hg) is a globally-distributed pollutant, toxic to humans and animals. Emissions are particularly high in Asia, and the source of exposure for humans there may also be different from other regions, including rice as well as fish consumption, particularly in contaminated areas. Yet the threats Asian wildlife face in rice-based ecosystems are as yet unclear. We sought to understand how Hg flows through rice-based food webs in historic mining and non-mining regions of Guizhou, China. We measured total Hg (THg) and methylmercury (MeHg) in soil, rice, 38 animal species (27 for MeHg) spanning multiple trophic levels, and examined the relationship between stable isotopes and Hg concentrations. Our results confirm biomagnification of THg/MeHg, with a high trophic magnification slope. Invertivorous songbirds had concentrations of THg in their feathers that were 15x and 3x the concentration reported to significantly impair reproduction, at mining and non-mining sites, respectively. High concentrations in specialist rice consumers and in granivorous birds, the later as high as in piscivorous birds, suggest rice is a primary source of exposure. Spiders had the highest THg concentrations among invertebrates and may represent a vector through which Hg is passed to vertebrates, especially songbirds. Our findings suggest there could be significant population level health effects and consequent biodiversity loss in sensitive ecosystems, like agricultural wetlands, across Asia, and invertivorous songbirds would be good subjects for further studies investigating this possibility. - Highlights: • Hg concentrations were measured across rice-based food webs in Guizhou, China. • Of 38 animal species, THg concentrations were highest for invertivorous songbirds. • High THg levels in rice pests and in granivorous birds suggest rice as a source. • Levels of THg in songbird feathers at mining site were among highest ever recorded. • Even at non-mining site, THg in such

  15. Cytological and molecular analysis of nonhost resistance in rice to wheat powdery mildew and leaf rust pathogens.

    Science.gov (United States)

    Cheng, Yulin; Yao, Juanni; Zhang, Hongchang; Huang, Lili; Kang, Zhensheng

    2015-07-01

    Cereal powdery mildews caused by Blumeria graminis and cereal rusts caused by Puccinia spp. are constant disease threats that limit the production of almost all important cereal crops. Rice is an intensively grown agricultural cereal that is atypical because of its immunity to all powdery mildew and rust fungi. We analyzed the nonhost interactions between rice and the wheat powdery mildew fungus B. graminis f. sp. tritici (Bgt) and the wheat leaf rust fungus Puccinia triticina (Ptr) to identify the basis of nonhost resistance (NHR) in rice against cereal powdery mildew and rust fungi at cytological and molecular levels. No visible symptoms were observed on rice leaves inoculated with Bgt or Ptr. Microscopic observations showed that both pathogens exhibited aberrant differentiation and significantly reduced penetration frequencies on rice compared to wheat. The development of Bgt and Ptr was also completely arrested at early infection stages in cases of successful penetration into rice leaves. Attempted infection of rice by Bgt and Ptr induced similar defense responses, including callose deposition, accumulation of reactive oxygen species, and hypersensitive response in rice epidermal and mesophyll cells, respectively. Furthermore, a set of defense-related genes were upregulated in rice against Bgt and Ptr infection. Rice is an excellent monocot model for genetic and molecular studies. Therefore, our results demonstrate that rice is a useful model to study the mechanisms of NHR to cereal powdery mildew and rust fungi, which provides useful information for the development of novel and durable strategies to control these important pathogens.

  16. Study of Rice Marketing System in Iran

    OpenAIRE

    Feizabadi, Yaser

    2011-01-01

    Rice comes second after wheat in Iran`s food consumption economy. Rising population and recent growth in GDP has made Iran one of the greatest rice importer countries all over the world. That is why rice marketing has always been a controversial issue in Iran`s agricultural economics. To study rice marketing system in Iran, this paper aims to calculate rice marketing margin, market efficiency and marketing cost coefficient in seaside Mazandaran province( where 70 percent of domestic rice prod...

  17. The absorption ability for carbohydrate between vigorous and weak spikelets in hybrid rice and its restorers

    International Nuclear Information System (INIS)

    Wang Xi; Tao Longxing; Tian Shulan; Huang Xiaolin; Yu Meiyu

    2000-01-01

    Some hybrid rice combinations and their restorers, II you2070 (indica/Indica) and its restorer2070, Shuangyou23 (Japonica/Japonica) with its restorer 91-23, sub-species hybrid rice Xieyou 413 (Indica/Japonica) with its restorer Zhong 413, were selected as rice material and planted in pot and field to study the differences of absorption ability for labelled carbohydrate between vigorous and weak spikelets, and to demonstrate the phenomenon of 'inter-grain apical dominance' in rice. It was shown that the absorbing rate of hybrid rice and it restorer for store material and for photo-material was 50% and 80% respectively, and the absorbing rate of hybrid rice was a litter higher than that of its restorer. However, there was a big difference between vigorous spikelets and weak spikelets in the absorbing ability for carbohydrate. The absorbing amount of vigorous spikelets was 10 times higher than that of the weak spikelets, especially in hybrid rice combinations. It was also observed that the 'inter-grain apical dominance' in hybrid rice was stronger than its restorer, which might be one of the main reasons for low seed setting in hybrid rice combination

  18. Mechanism study of sulfur fertilization mediating copper translocation and biotransformation in rice (Oryza sativa L.) plants.

    Science.gov (United States)

    Sun, Lijuan; Yang, Jianjun; Fang, Huaxiang; Xu, Chen; Peng, Cheng; Huang, Haomin; Lu, Lingli; Duan, Dechao; Zhang, Xiangzhi; Shi, Jiyan

    2017-07-01

    Metabolism of sulfur (S) is suggested to be an important factor for the homeostasis and detoxification of Cu in plants. We investigated the effects of S fertilizers (S 0 , Na 2 SO 4 ) on Cu translocation and biotransformation in rice plants by using multiple synchrotron-based techniques. Fertilization of S increased the biomass and yield of rice plants, as well as the translocation factor of Cu from root to shoot and shoot to grain, resulting in enhanced Cu in grain. Sulfur K-edge X-ray near edge structure (XANES) analysis showed that fertilization of S increased the concentration of glutathione in different rice tissues, especially in rice stem and leaf. Copper K-edge XANES results indicated that a much higher proportion of Cu (I) species existed in rice grain than husk and leaf, which was further confirmed by soft X-ray scanning transmission microscopy results. Sulfur increased the proportion of Cu (I) species in rice grain, husk and leaf, suggesting the inducing of Cu (II) reduction in rice tissues by S fertilization. These results suggested that fertilization of S in paddy soils increased the accumulation of Cu in rice grain, possibly due to the reduction of Cu (II) to Cu (I) by enhancing glutathione synthesis and increasing the translocation of Cu from shoot to grain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Nicaragua - Rice and Banana Farmers

    Data.gov (United States)

    Millennium Challenge Corporation — This report is an impact evaluation of two components of the Rural Business Development Program (RBD) in Nicaragua, specifically the components benefitting rice and...

  20. Sorghum and rice: Mali

    International Nuclear Information System (INIS)

    2003-01-01

    Agriculture is the mainstay of the Malian economy and yet cereal imports absorb 6.5% of GDP. Food self-sufficiency is therefore a national priority. The Joint FAO/IAEA Division is supporting a programme to improve local varieties of sorghum and rice by using nuclear techniques to develop new cultivars that will produce higher yields under Mali's semi-arid climatic conditions. (IAEA)

  1. Sorbents based on carbonized rice peel

    International Nuclear Information System (INIS)

    Mansurova, R. M.; Taipova, R. A.; Zhylybaeva, N. K.; Mansurov, Z. A.; Bijsenbaev, M. A.

    2004-01-01

    The process receiving of sorbents based on carbonized rice peel (RP) was received and their sorption properties were investigated. Processing carbonization of samples leading on station, this was developed in laboratory of hybrid technology. Carbonization of samples was realized in nitric atmosphere on 400-8000 deg. C. On raising temperature of carbonization content of carbon in samples is rice, hydrogen and oxygen is reduce as a result isolation of volatility products is discover. The samples carbonized on 650 deg. C (910 m 2 /g) owners with maximum removed surface is discover. On carbonization temperature 600-800 deh. C the sorption of ions, which carbonized by sorbents based on rice peel is run to 95-100 %. Electron-microscopic investigation of samples leaded on EM-125 mechanism by accelerating pressure 100 kV. From electron-microscopic print of original samples of RP it is evident, that sample consists of carbonic fractions of different species: carbonic fiber of rounded fractions, fractions of ellipsoid form and of more thickly carbonic structure. Increasing sizes of pores and modification structure of synthesized sorbent is occur during carbonization process. The RP-samples, which carbonized by 650 deg. C has the higher specific surface. Samples consist of thin carbonic scum and reducing specific surface, by higher temperature

  2. Diversity of some endophytic fungi associated with rice black bug Paraeucosmetus pallicornis on rice plant

    OpenAIRE

    Nur, Amin; La Daha; Nurariaty, Agus; Ade, Rosmana; Muh., Fadlan

    2015-01-01

    A new rice insect pest was sighted in some rice producing areas of South Sulawesi Province, Indonesia. This pest is rice black bugs Paraeucosmetus pallicornis. The research aimed to isolation of fungi associated with rice black bugs Paraeucosmetus pallicornis, so as to know the cause of a bitter taste to the rice. The isolation of the fungi consist of three kinds of treatment, namely rice black bugs without sterilization, with sterilization and rice black bugs cut and sterilized. The resul...

  3. Broken rice kernels and the kinetics of rice hydration and texture during cooking.

    Science.gov (United States)

    Saleh, Mohammed; Meullenet, Jean-Francois

    2013-05-01

    During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.

  4. The Haitian Rice Tariff

    Directory of Open Access Journals (Sweden)

    Mats Lundahl

    2016-04-01

    Full Text Available Se ha argumentado que los problemas agríco-las de Haití derivan de la tarifa del arroz de a mediados de los años noventa. Antes, supues-tamente, Haití fue autosuficiente, abastecida por su producción doméstica. Después de la reducción, el mercado haitiano se inundó en importaciones de arroz barato de los EEUU, lo cual despojó a los campesinos de sus fincas, convirtiendolos en migrantes internos, hacia los empleos de bajo pago de las ciudades. El artículo rechaza ese argumento y demuestra que es falso. La malnutrición fue un fenómeno extendido en Haití mucho antes de la reducción de la tarifa del arroz, la cual tampoco tuvo un gran impacto en la importación y la producción doméstica del arroz. Lo que sí impulsó el aumento de las importaciones fue el crecimiento de la población. También el artículo argumenta que un aumento de la tarifa del arroz no solucionará el problema de la alimentación que sufre Haití. English: It has been argued that Haiti’s agricultural problems derive from the reduction of the rice tariff in the mid-1990s. Before that Haiti was allegedly able to meet its food needs by domestic production. After the reduction the Haitian market was swamped by imports of cheap American rice which drove the farmers off their lands and forced them to migrate to low-wage industrial jobs in the cities. The article demonstrates that the argument is false. Malnutrition was widespread in Haiti long before the rice tariff reduction, and the latter did not have much of an impact on rice imports and domestic production. Instead, the main driving force behind imports appears to be population growth. It is also shown that an increase of the rice tariff will not solve Haiti’s food problem.

  5. Impact of Day Intervals on Sequential Infestations of the Rice Leaffolder (Guenée (Lepidoptera: Pyralidae and the White-Backed Rice Planthopper (Horváth on Rice Grain Damage

    Directory of Open Access Journals (Sweden)

    Li-Ben Jiang

    2014-01-01

    Full Text Available The present study illustrates that different day intervals (DIs between the sequential infestations of two pest species, the rice leaffolder (RLF Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae and the white-backed rice planthopper (WBPH Sogatella furcifera Horváth (Hemiptera: Delphacidae, have a significant impact on the rice yield loss rate (YLR and on the carbohydrate contents of rice plants. For WBPH release after RLF release (WRARR, the YLR decreased with the increasing DIs, and the YLR at the 24 DI was significantly lower compared to that at the 6 and 12 DIs and had a minimum value for a simultaneous infestation of the two pest species (SITS. In contrast, for RLF release after WBPH release (RRAWR, the YLR at the 24 DI had a maximum value and was significantly higher compared to that at the 6 and 12 DIs and the SITS. These findings indicate that damaged rice plants gradually recover, with an increase in the DI for WRARR. The above results were demonstrated by biochemical tests. Therefore, the sequential infestation of the two pest species and their DIs should be considered for integrated pest management (IPM and control strategies for rice pests.

  6. Nutritional test of rice in rats

    International Nuclear Information System (INIS)

    Horii, Masaji; Yoshikawa, Seiji

    1980-01-01

    Behaviors on N derived from rice were followed up by means of 15 N-labeled rice. In the first test, the single unpolished rice diet and the diet of rice and bean lecithin (4.5%) produced urinary excretion of 10 - 12% of 15 N, and that of rice and mannan from devil's tongue (3%), 16 - 20%. The single unpolished rice diet showed slightly more urinary excretion of 15 N, and the other 2 diets showed a similar proportion of 15 N in 3 days. The results indicated that the diet containing mannan from devil's tongue resulted in a poor N absorption by rice, a large quantity of N being excreted over a long period of time. This suggested differences and time lags in the excretion of rice N into the stool and urine depending on the diet constitution. With the unpolished rice diet, a small quantity of rice protein was not absorbed, but was excreted. In the 2nd test with 15 N-polished rice, the urinary excretion rate was 11.44% for a single rice diet, 11.16% for a mixed diet of rice and bean (1:1 in protein), 10.99% for rice and egg yolk, 9.66% for rice, bean and egg yolk and 8.10% for rice and bean lecithin. This decrease in urinary excretion indicated a corresponding increase in absorption of rice protein. (Chiba, N.)

  7. Introgression from cultivated rice alters genetic structures of wild relative populations: implications for in situ conservation

    Science.gov (United States)

    Jin, Xin; Chen, Yu; Liu, Ping; Li, Chen; Cai, Xingxing; Rong, Jun

    2018-01-01

    Abstract Maintaining genetic integrity is essential for in situ and ex situ conservation of crop wild relative (CWR) species. However, introgression of crop alleles into CWR species/populations may change their genetic structure and diversity, resulting in more invasive weeds or, in contrast, the extinction of endangered populations. To determine crop-wild introgression and its consequences, we examined the genetic structure and diversity of six wild rice (Oryza rufipogon) populations under in situ conservation in China. Thirty-four simple sequence repeat (SSR) and 34 insertion/deletion markers were used to genotype the wild rice populations and two sets of rice cultivars (O. sativa), corresponding to the two types of molecular markers. Shared alleles and STRUCTURE analyses suggested a variable level of crop-wild introgression and admixture. Principal coordinates and cluster analyses indicated differentiation of wild rice populations, which was associated with the spatial distances to cultivated rice fields. The level of overall genetic diversity was comparable between wild rice populations and rice cultivars, but a great number of wild-specific alleles was detected in the wild populations. We conclude based on the results that crop-wild introgression can considerably alter the pattern of genetic structure and relationships of CWR populations. Appropriate measures should be taken for effective in situ conservation of CWR species under the scenario of crop-wild introgression. PMID:29308123

  8. [Exposure degree of important non-target arthropods to Cry2Aa in Bt rice fields].

    Science.gov (United States)

    Zhang, Qing-Ling; Li, Yun-He; Hua, Hong-Xia; Yang, Chang-Ju; Wu, Hong-Jin; Peng, Yu-Fa

    2013-06-01

    Based on the principle of "risk = hazard x exposure", the selected representative nontarget organisms in the assessment of the potential effects of insect-resistant genetically modified (GM) crops on non-target arthropods in laboratory are generally the arthropod species highly exposed to the insecticidal proteins expressed by the GM crops in farmland ecosystem. In order to understand the exposure degree of the important arthropod species to Cry proteins in Bt rice fields, and to select the appropriate non-target arthropods in the risk assessment of insect-resistant GM crops, the enzyme-linked immunosorbent assay (ELISA) was conducted to measure the Cry2Aa protein concentration in the arthropods collected from the cry2Aa rice fields at different rice growth stages. The results showed that there was a significant difference in the Cry2Aa content protein concentration in different arthropod species. Some species did not contain Cry2Aa protein, while some species contained larger amounts of Cry2Aa protein. Relative to the arthropods colleted after rice anthesis, the arthropods colleted in rice anthesis contained relative higher concentrations of Cry2Aa protein, especially for the predacious arthropods. No Cry proteins were detected in parasitic arthropods. This study provided references for the laboratory assessment of the effects of GM rice on nontarget arthropods.

  9. Characterization of 140 Japanese and world rice collections cultivated in Nihonmatsu-city in Fukushima in terms of radiocesium activity concentrations in seed grains and straws to explore rice cultivars with low radiocesium accumulation

    International Nuclear Information System (INIS)

    Katsuhiro Kojima; Djedidi Salem

    2017-01-01

    We studied varietal difference in radiocesium accumulation by using Japanese and World rice collection for future development of low accumulation varieties. As a result, the radiocesium activity concentration varied by 12- and 22-fold in seed grains and straws, respectively. When we examined the seed grain to straw ratio of radiocesium activity concentration, paddy rice cultivars of Japonica sub-species showed a lower result than Indica and Javanica paddy rice cultivars. These observations suggest that the Japonica paddy rice cultivars may have the property of repressing radioactive cesium translocation to edible parts. (author)

  10. A microarray analysis of the rice transcriptome and its comparison to Arabidopsis

    DEFF Research Database (Denmark)

    Ma, Ligeng; Chen, Chen; Liu, Xigang

    2005-01-01

    Arabidopsis and rice are the only two model plants whose finished phase genome sequence has been completed. Here we report the construction of an oligomer microarray based on the presently known and predicted gene models in the rice genome. This microarray was used to analyze the transcriptional...... with similar genome-wide surveys of the Arabidopsis transcriptome, our results indicate that similar proportions of the two genomes are expressed in their corresponding organ types. A large percentage of the rice gene models that lack significant Arabidopsis homologs are expressed. Furthermore, the expression...... patterns of rice and Arabidopsis best-matched homologous genes in distinct functional groups indicate dramatic differences in their degree of conservation between the two species. Thus, this initial comparative analysis reveals some basic similarities and differences between the Arabidopsis and rice...

  11. Phosphorus Use Efficiency by Brazilian Upland Rice Genotypes Evaluated by the {sup 32}P Dilution Technique

    Energy Technology Data Exchange (ETDEWEB)

    Franzini, V. I.; Mendes, F. L. [Brazilian Agricultural Research Corporation, EMBRAPA-Amazonia Oriental, Belem, PA (Brazil); Muraoka, T.; Da Silva, E. C. [Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP (Brazil); Adu-Gyamfi, J. J. [Soil and Water Management and Crop Nutrition Laboratory, International Atomic Energy Agency, Vienna (Austria)

    2013-11-15

    The objectives of this work were to identify the most efficient upland rice genotypes in phosphorus (P) utilization, and to verify if P from the seed affects the classification of upland rice genotypes on P uptake efficiency. The experiment was conducted in a greenhouse of the Center for Nuclear Energy in Agriculture (CENA/USP), Piracicaba, Sao Paulo, Brazil, using the {sup 32}P isotope technique, and plants were grown in pots with samples of dystrophic Typic Haplustox (Oxisol). The experimental design was completely randomized with four replications. The treatments consisted of 47 upland rice genotypes and two standard plant species, efficient or inefficient in P uptake. The results were assessed through correlation and cluster analysis (multivariate). The Carisma upland rice genotype was the most efficient in P uptake, and Caripuna was the most efficient on P utilization. The P derived from seed does not influence the identification of upland rice genotypes in P uptake efficiency. (author)

  12. Quantitative Trait Loci Analysis of Allelopathy in Rice

    DEFF Research Database (Denmark)

    Jensen, L B; Courtois, B; Olofsdotter, M

    2008-01-01

    The allelopathic potential of rice (Oryza sativa L.) against Echinochloa crus-galli (L.) Beauv. was investigated under both laboratory and greenhouse conditions. A population of 150 recombinant inbred lines (RILs) was derived through single-seed descent from a cross between the indica cultivar AC...... the population phenotype was normally distributed. Two quantitative trait loci (QTLs) were located on chromosomes 4 and 7, explaining 20% of the phenotypic variation. A second relay seeding experiment was set up, this time including charcoal in the perlite. This screening showed that the allelopathic rice...... varieties did not have any effect on the weed species when grown with charcoal, the charcoal reversing the effect of any potential allelochemicals exuded from the rice roots. The second phenotypic experiment was conducted under greenhouse conditions in pots. Thirteen QTLs were detected for four different...

  13. 21 CFR 137.350 - Enriched rice.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose and...

  14. Uptake, translocation and transformation of antimony in rice (Oryza sativa L.) seedlings.

    Science.gov (United States)

    Cai, Fei; Ren, Jinghua; Tao, Shu; Wang, Xilong

    2016-02-01

    Antimony (Sb), as a toxic metalloid, has been gaining increasing research concerns due mainly to its severe pollution in many places. Rice has been identified to be the dominant intake route of Sb by residents close to the Sb mining areas. A hydroponic experiment was conducted to investigate the difference in uptake, translocation and transformation of Sb in rice seedlings of four cultivars exposed to 0.2 or 1.0 mg/L of Sb(V). The results showed that mass concentration of iron plaque (mg/kg FW) formed at the root surfaces of cultivar N was the highest among all tested cultivars at both low and high exposure levels of Sb(V). The accumulated Sb concentration in iron plaque significantly increased with an increase in mass concentration of iron plaque formed at the rice root. The total amount of iron plaque (mg/pot) at rice root generally increased with increasing exposed Sb(V) concentration, which was closely associated with the increasing lipid peroxidation in roots. Concentration percentage of Sb in rice root significantly reduced as the corresponding value in the iron plaque increased, suggesting that iron plaque formation strongly suppressed uptake of Sb by rice root. Sb concentration in rice tissues followed an order: root > stem, leaf. The japonica rice (cultivars N and Z) exhibited a stronger translocation tendency of Sb from root to stem than indica hybrid rice (cultivars F and G). Translocation of Sb from root of cultivar F to its stem and leaf was sharply enhanced with increasing Sb exposure concentration. Sb(V) could be reduced to Sb(III) in rice tissues, especially in stems (10-26% of the total Sb). For the sake of food safety, the difference in uptake, translocation and transformation of Sb in rice species planted in Sb-contaminated soils should be taken into consideration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Speciation and Localization of Arsenic in White and Brown Rice Grains

    Energy Technology Data Exchange (ETDEWEB)

    Meharg, Andrew A.; Lombi, Enzo; Williams, Paul N.; Scheckel, Kirk G.; Feldmann, Joerg; Raab, Andrea; Zhu, Yongguan; Islam, Rafiql (EPA); (Bangladesh); (UCopenhagen); (Aberdeen); (Chinese Aca. Sci.)

    2008-06-30

    Synchrotron-based X-ray fluorescence (S-XRF) was utilized to locate arsenic (As) in polished (white) and unpolished (brown) rice grains from the United States, China, and Bangladesh. In white rice As was generally dispersed throughout the grain, the bulk of which constitutes the endosperm. In brown rice As was found to be preferentially localized at the surface, in the region corresponding to the pericarp and aleurone layer. Copper, iron, manganese, and zinc localization followed that of arsenic in brown rice, while the location for cadmium and nickel was distinctly different, showing relatively even distribution throughout the endosperm. The localization of As in the outer grain of brown rice was confirmed by laser ablation ICP?MS. Arsenic speciation of all grains using spatially resolved X-ray absorption near edge structure (?-XANES) and bulk extraction followed by anion exchange HPLC?ICP?MS revealed the presence of mainly inorganic As and dimethylarsinic acid (DMA). However, the two techniques indicated different proportions of inorganic:organic As species. A wider survey of whole grain speciation of white (n = 39) and brown (n = 45) rice samples from numerous sources (field collected, supermarket survey, and pot trials) showed that brown rice had a higher proportion of inorganic arsenic present than white rice. Furthermore, the percentage of DMA present in the grain increased along with total grain arsenic.

  16. Weed communities of rain-fed lowland rice vary with infestation by Rhamphicarpa fistulosa

    Science.gov (United States)

    Houngbédji, Tossimidé; Dessaint, Fabrice; Nicolardot, Bernard; Shykoff, Jacqui A.; Gibot-Leclerc, Stéphanie

    2016-11-01

    The facultative hemiparasitic plant Rhamphicarpa fistulosa (Orobanchaceae) thrives in seasonally wet soils in sub-Saharan Africa, mainly in marginal lowland rice growing environments where weeds are already a major constraint for rice production. Because lowland rice production is increasing in tropical Africa, it is important to ascertain the influence of R. fistulosa on weed plant communities in these rice-growing habitats. We investigated weed plant community richness and composition at four different levels of R. fistulosa infestation across two years of surveys from lowland rice fields in northern Togo (West Africa). Despite a lack of significant differences in community richness among sites with different R. fistulosa infestation levels, there were significant differences in community composition, both when estimated from presence-absence data and from relative abundance data, after controlling statistically for geographic proximity among sites. Rhamphicarpa fistulosa infestation, therefore, may influence the competitive balance between rice and its weeds and shape weed community structure. However, experimental studies are required to elucidate the weed host range of R. fistulosa and the direct and indirect effects of this hemiparasite in rice fields in order to predict its net impact on rice and its weed species.

  17. Uptake, translocation and transformation of antimony in rice (Oryza sativa L.) seedlings

    International Nuclear Information System (INIS)

    Cai, Fei; Ren, Jinghua; Tao, Shu; Wang, Xilong

    2016-01-01

    Antimony (Sb), as a toxic metalloid, has been gaining increasing research concerns due mainly to its severe pollution in many places. Rice has been identified to be the dominant intake route of Sb by residents close to the Sb mining areas. A hydroponic experiment was conducted to investigate the difference in uptake, translocation and transformation of Sb in rice seedlings of four cultivars exposed to 0.2 or 1.0 mg/L of Sb(V). The results showed that mass concentration of iron plaque (mg/kg FW) formed at the root surfaces of cultivar N was the highest among all tested cultivars at both low and high exposure levels of Sb(V). The accumulated Sb concentration in iron plaque significantly increased with an increase in mass concentration of iron plaque formed at the rice root. The total amount of iron plaque (mg/pot) at rice root generally increased with increasing exposed Sb(V) concentration, which was closely associated with the increasing lipid peroxidation in roots. Concentration percentage of Sb in rice root significantly reduced as the corresponding value in the iron plaque increased, suggesting that iron plaque formation strongly suppressed uptake of Sb by rice root. Sb concentration in rice tissues followed an order: root > stem, leaf. The japonica rice (cultivars N and Z) exhibited a stronger translocation tendency of Sb from root to stem than indica hybrid rice (cultivars F and G). Translocation of Sb from root of cultivar F to its stem and leaf was sharply enhanced with increasing Sb exposure concentration. Sb(V) could be reduced to Sb(III) in rice tissues, especially in stems (10–26% of the total Sb). For the sake of food safety, the difference in uptake, translocation and transformation of Sb in rice species planted in Sb-contaminated soils should be taken into consideration. - Highlights: • Sb(V) caused lipid peroxidation and increased iron plaque formation at root surface. • The iron plaque may suppress uptake of Sb by rice. • Cultivars

  18. Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market.

    Science.gov (United States)

    Katsurayama, Aline M; Martins, Ligia M; Iamanaka, Beatriz T; Fungaro, Maria Helena P; Silva, Josué J; Frisvad, Jens C; Pitt, John I; Taniwaki, Marta H

    2018-02-02

    The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production systems, wetland from the state of Rio Grande do Sul, dryland, from the state of Maranhão and market samples from the state of São Paulo, were analyzed for fungi belonging to Aspergillus section Flavi and the presence of aflatoxins. Twenty-three soil samples from wetland and dryland were also analyzed. A total of 383 Aspergillus section Flavi strains were isolated from rice and soil samples. Using a polyphasic approach, with phenotypic (morphology and extrolite profiles) and molecular data (beta-tubulin gene sequences), five species were identified: A. flavus, A. caelatus, A. novoparasiticus, A. arachidicola and A. pseudocaelatus. This is the first report of these last three species from rice and rice plantation soil. Only seven (17%) of the A. flavus isolates produced type B aflatoxins, but 95% produced kojic acid and 69% cyclopiazonic acid. Less than 14% of the rice samples were contaminated with aflatoxins, but two of the market samples were well above the maximum tolerable limit (5μg/kg), established by the Brazilian National Health Surveillance Agency. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Speciation and monitoring test for inorganic arsenic in white rice flour.

    Science.gov (United States)

    Narukawa, Tomohiro; Hioki, Akiharu; Chiba, Koichi

    2012-02-01

    A monitoring test for arsenic species in white rice flour was developed and applied to flours made from 20 samples of polished rice collected from locations all over Japan. The arsenic species in white rice flour made from five samples each of four types of rice were analyzed by HPLC-ICP-MS after a heat-assisted aqueous extraction. The total arsenic and major and minor element concentrations in the white rice flours were measured by ICP-MS and ICP-OES after microwave-assisted digestion. 91 ± 1% of the arsenic in the flours was extractable. Concentrations of arsenite [As(III)], arsenate [As(V)], and dimethylarsinic acid (DMAA) were closely positively correlated with the total arsenic concentrations. The total arsenic concentration in flours made from rice collected around Japan was 0.15 ± 0.07 mg kg(-1) (highest, 0.32 mg kg(-1)), which is very low. It was thus confirmed that the white rice flour samples collected in this experiment were not suffered from noticeable As contamination.

  20. Fenton process-affected transformation of roxarsone in paddy rice soils: Effects on plant growth and arsenic accumulation in rice grain.

    Science.gov (United States)

    Qin, Junhao; Li, Huashou; Lin, Chuxia

    2016-08-01

    Batch and greenhouse experiments were conducted to examine the effects of Fenton process on transformation of roxarsone in soils and its resulting impacts on the growth of and As uptake by a rice plant cultivar. The results show that addition of Fenton reagent markedly accelerated the degradation of roxarsone and produced arsenite, which was otherwise absent in the soil without added Fenton reagent. Methylation of arsenate was also enhanced by Fenton process in the earlier part of the experiment due to abundant supply of arsenate from Roxarsone degradation. Overall, addition of Fenton reagent resulted in the predominant presence of arsenate in the soils. Fenton process significantly improved the growth of rice in the maturity stage of the first crop, The concentration of methylated As species in the rice plant tissues among the different growth stages was highly variable. Addition of Fenton reagent into the soils led to reduced uptake of soil-borne As by the rice plants and this had a significant effect on reducing the accumulation of As in rice grains. The findings have implications for understanding As biogeochemistry in paddy rice field receiving rainwater-borne H2O2 and for development of mitigation strategies to reduce accumulation of As in rice grains. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice

    OpenAIRE

    Wang, Hongru; Garrett Vieira, Filipe Jorge; Crawford, Jacob E.; Chu, Chengcai; Nielsen, Rasmus

    2017-01-01

    The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon, are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genome...

  2. Detection of DNA fingerprints of cultivated rice by hybridization with a human minisatellite DNA probe

    International Nuclear Information System (INIS)

    Dallas, J.F.

    1988-01-01

    A human minisatellite DNA probe detects several restriction fragment length polymorphisms in cultivars of Asian and African rice. Certain fragments appear to be inherited in a Mendelian fashion and may represent unlinked loci. The hybridization patterns appear to be cultivar-specific and largely unchanged after the regeneration of plants from tissue culture. The results suggest that these regions of the rice genome may be used to generate cultivar-specific DNA fingerprints. The demonstration of similarity between a human minisatellite sequence and polymorphic regions in the rice genome suggests that such regions also occur in the genomes of many other plant species

  3. Zinc fertilization of flooded rice

    International Nuclear Information System (INIS)

    1981-02-01

    Local scientists studied Zn fertilization of flooded rice soils in Bangladesh, India, Indonesia, the Republic of Korea, Egypt, the Philippines, Thailand and Turkey. Diagnosis of Zn deficiency was carried out for submerged rice soils. Soil maps were prepared, designating areas as low, medium and high in Zn, based on Zn extraction with DTPA and HCl solutions and on rice leaf analysis. The effectiveness of various Zn fertilizer sources and methods of application in field and greenhouse experiments was measured, using 65 Zn. The percent Zn derived from fertilizer was shown to be a much more sensitive measure of efficiency than yield or total uptake

  4. The parasitoids of the African white rice borer, Maliarpha separatella Ragonot (Lepidoptera: Pyralidae)

    OpenAIRE

    Polaszek, A.; Fitton, M.G.; Bianchi, G.; Huddleston, T.

    2017-01-01

    A key is provided for the recognition of the hymenopterous parasitoids of the African white rice borer, Maliarpha separatella Ragonot, a pest of rice in Africa and Madagascar. Five species are described as new: Braconidae: Chelonus maudae Huddleston, Rhacanotus carinafus Polaszek; Ichneumonidae: Prisfomerus bullis Fitton, Prisfomerus caris Fitton, Venturia jordanae Fitton. The following synonyms are proposed: Goniozus indicus Muesebeck, G. natalensis Gordh and G. procerae Risbec are synonymiz...

  5. Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

    OpenAIRE

    Pazini,Juliano de Bastos; Grützmacher,Anderson Dionei; Martins,José Francisco da Silva; Pasini,Rafael Antônio; Rakes,Matheus

    2016-01-01

    ABSTRACT Telenomus and Trichogramma species stand out as agents for the biological control in rice crops, and the main strategy for preserving them is the use of selective pesticides. This study aimed at evaluating the toxicity of pesticides used in irrigated rice crop on Telenomus podisi Ashmead (Hymenoptera: Platygastridae) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). Adults of these parasitoids were exposed to dry residues of pesticides, in a completely randomized exp...

  6. Rice vaikib salavanglaist / Tõnis Erilaid

    Index Scriptorium Estoniae

    Erilaid, Tõnis, 1943-

    2005-01-01

    Euroopasse visiidile sõitev USA välisminister Condoleezza Rice külastab Saksamaad, Rumeeniat, Ukrainat ja Belgiat. Süüdistusi CIA lennukite maandumiste ja salavanglate kohta ei olevat tal kavas kommenteerida

  7. Red Yeast Rice: An Introduction

    Science.gov (United States)

    ... rice are used in food products in Chinese cuisine, including Peking duck. Others have been sold as ... Medicine . 2010;170(19):1722–1727. Halbert SC, French B, Gordon RY, et al. Tolerability of red ...

  8. indica rice (Oryza sativa L.)

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... fresh weight, regeneration, proline level and total protein content in salt sensitive indica rice cv. IR 64. For callus ... INTRODUCTION. Salinity is one of the ... Proline is reported to reduce the enzyme denaturation caused due.

  9. Os11Gsk gene from a wild rice, Oryza rufipogon improves yield in rice.

    Science.gov (United States)

    Thalapati, Sudhakar; Batchu, Anil K; Neelamraju, Sarla; Ramanan, Rajeshwari

    2012-06-01

    Chromosomal segments from wild rice species Oryza rufipogon, introgressed into an elite indica rice restorer line (KMR3) using molecular markers, resulted in significant increase in yield. Here we report the transcriptome analysis of flag leaves and fully emerged young panicles of one of the high yielding introgression lines IL50-7 in comparison to KMR3. A 66-fold upregulated gene Os11Gsk, which showed no transcript in KMR3 was highly expressed in O. rufipogon and IL50-7. A 5-kb genomic region including Os11Gsk and its flanking regions could be PCR amplified only from IL50-7, O. rufipogon, japonica varieties of rice-Nipponbare and Kitaake but not from the indica varieties, KMR3 and Taichung Native-1. Three sister lines of IL50-7 yielding higher than KMR3 showed presence of Os11Gsk, whereas the gene was absent in three other ILs from the same cross having lower yield than KMR3, indicating an association of the presence of Os11Gsk with high yield. Southern analysis showed additional bands in the genomic DNA of O. rufipogon and IL50-7 with Os11Gsk probe. Genomic sequence analysis of ten highly co-expressed differentially regulated genes revealed that two upregulated genes in IL50-7 were derived from O. rufipogon and most of the downregulated genes were either from KMR3 or common to KMR3, IL50-7, and O. rufipogon. Thus, we show that Os11Gsk is a wild rice-derived gene introduced in KMR3 background and increases yield either by regulating expression of functional genes sharing homology with it or by causing epigenetic modifications in the introgression line.

  10. Investigating Pigment Radicals in Black Rice Using HPLC and Multi-EPR.

    Science.gov (United States)

    Nakagawa, Kouichi; Maeda, Hayato

    2017-01-01

    We investigated the location and distribution of paramagnetic species in black and white rice using electron paramagnetic resonance (EPR), X-band (9 GHz) EPR imaging (EPRI), and HPLC. EPR primarily detected two paramagnetic species in black rice, which were identified as a stable radical and Mn 2+ species, based on the g values and hyperfine components of the EPR signals. The signal from the stable radical appeared at g ≈ 2.00 and was relatively strong and stable. Subsequent noninvasive two-dimensional (2D) EPRI revealed that this stable radical was primarily located in the pigmented region of black rice, while very few radicals were observed in the rice interior. Pigments extracted from black rice were analyzed using HPLC; the major compound was found to be cyanidin-3-glucoside. EPR and HPLC results indicate that the stable radical was only found within the pigmented region of the rice, and that it could either be cyanidin-3-glucoside, or one of its oxidative decomposition products.

  11. Metabolomic Profiles of Aspergillus oryzae and Bacillus amyloliquefaciens During Rice Koji Fermentation

    Directory of Open Access Journals (Sweden)

    Da Eun Lee

    2016-06-01

    Full Text Available Rice koji, used early in the manufacturing process for many fermented foods, produces diverse metabolites and enzymes during fermentation. Using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS, ultrahigh-performance liquid chromatography linear trap quadrupole ion trap tandem mass spectrometry (UHPLC-LTQ-IT-MS/MS, and multivariate analysis we generated the metabolite profiles of rice koji produced by fermentation with Aspergillus oryzae (RK_AO or Bacillus amyloliquefaciens (RK_BA for different durations. Two principal components of the metabolomic data distinguished the rice koji samples according to their fermenter species and fermentation time. Several enzymes secreted by the fermenter species, including α-amylase, protease, and β-glucosidase, were assayed to identify differences in expression levels. This approach revealed that carbohydrate metabolism, serine-derived amino acids, and fatty acids were associated with rice koji fermentation by A. oryzae, whereas aromatic and branched chain amino acids, flavonoids, and lysophospholipids were more typical in rice koji fermentation by B. amyloliquefaciens. Antioxidant activity was significantly higher for RK_BA than for RK_AO, as were the abundances of flavonoids, including tricin, tricin glycosides, apigenin glycosides, and chrysoeriol glycosides. In summary, we have used MS-based metabolomics and enzyme activity assays to evaluate the effects of using different microbial species and fermentation times on the nutritional profile of rice koji.

  12. Mutant heterosis in rice

    International Nuclear Information System (INIS)

    1987-01-01

    In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent

  13. Assessing farmers' community readiness towards the enhancement of natural enemy population in rice fields in Malacca

    Science.gov (United States)

    Fairuz, K.; Idris, A. G.; Syahrizan, S.; Hatijah, K.

    2018-04-01

    Malacca has committed to be a green technology state by the year 2020. Agriculture is one of the main industries that have been highlighted to achieve this goal especially rice farming activities. Some limitations for this issue have restricted the accomplishment of the plan including pesticide usage among rice farmers. The use of chemicals in rice field need to be reduced significantly in order to support the goal. One of the indicators to the successfulness of pesticide reduction is the increasing numbers of natural enemies' species abundance and population in the rice field. Natural enemies were important to regulate pest populations in rice field naturally. Farmers' readiness to participate in this issue is very important to ensure the successfulness. The level of readiness of farmers' community will determine whether they are ready or not to execute the plan. Unfortunately, such information in rice farmers' community was not properly measured. Thus this study was aimed to assess the readiness level of rice farmers' community to change in order to enhance natural enemies in their rice field. This study was adapting the CR model as its theoretical framework. Three rice farming area in Malacca were involved in this study namely, Jasin, Melaka Tengah and Alor Gajah. Questionnaires were used as major instrument and were randomly distributed to 224 farmers. Data collected were tested for their reliability, significance and level of readiness. Knowledge of issue, knowledge of effort and resources dimensions were found influencing the readiness dimension significantly, whilst the attitude and leadership dimensions were not. Generally, the level of readiness for farmers' community in Malacca was found in the sixth or initial stage, where some of them initially have started to practice a few related activities to enhance the natural enemies' population in their rice field. Continuous support and assistant from the leaders and local authorities are crucially needed in

  14. Fusarium spp. associated with rice Bakanae: ecology, genetic diversity, pathogenicity and toxigenicity

    DEFF Research Database (Denmark)

    Wulff, E.G.; Sørensen, Jens Laurids; Lubeck, M.

    2010-01-01

    symptoms of Bakanae on rice, some species (i.e. F. fujikuroi) being more pathogenic than others. The ability to produce fumonisins (FB1 and FB2) and gibberellin A3 in vitro also differed according to the Fusarium species. While fumonisins were produced by most of the strains of F. verticillioides and F....... proliferatum, gibberellin A3 was only produced by F. fujikuroi. Neither fumonisin nor gibberellin was synthesized by most of the strains of F. andiyazi. These findings provide new information on the variation within the G. fujikuroi species complex associated with rice seed and Bakanae disease....

  15. Realistic Simulation of Rice Plant

    Directory of Open Access Journals (Sweden)

    Wei-long DING

    2011-09-01

    Full Text Available The existing research results of virtual modeling of rice plant, however, is far from perfect compared to that of other crops due to its complex structure and growth process. Techniques to visually simulate the architecture of rice plant and its growth process are presented based on the analysis of the morphological characteristics at different stages. Firstly, the simulations of geometrical shape, the bending status and the structural distortion of rice leaves are conducted. Then, by using an improved model for bending deformation, the curved patterns of panicle axis and various types of panicle branches are generated, and the spatial shape of rice panicle is therefore created. Parametric L-system is employed to generate its topological structures, and finite-state automaton is adopted to describe the development of geometrical structures. Finally, the computer visualization of three-dimensional morphologies of rice plant at both organ and individual levels is achieved. The experimental results showed that the proposed methods of modeling the three-dimensional shapes of organs and simulating the growth of rice plant are feasible and effective, and the generated three-dimensional images are realistic.

  16. Increasing rice plant growth by Trichoderma sp.

    Science.gov (United States)

    Doni, Febri; Isahak, Anizan; Zain, Che Radziah Che Mohd; Sulaiman, Norela; Fathurahman, F.; Zain, Wan Nur Syazana Wan Mohd.; Kadhimi, Ahsan A.; Alhasnawi, Arshad Naji; Anhar, Azwir; Yusoff, Wan Mohtar Wan

    2016-11-01

    Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

  17. Storage stability of flour-blasted brown rice

    Science.gov (United States)

    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. Stomatal conductance, mesophyll conductance, and transpiration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought.

    Science.gov (United States)

    Ouyang, Wenjing; Struik, Paul C; Yin, Xinyou; Yang, Jianchang

    2017-11-02

    Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (gs) and mesophyll conductance (gm) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the gm/gs ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low gs in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher gm, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in gm under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the gm/gs ratio via modifying anatomical traits. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  19. Massive gene losses in Asian cultivated rice unveiled by comparative genome analysis

    Directory of Open Access Journals (Sweden)

    Itoh Takeshi

    2010-02-01

    Full Text Available Abstract Background Rice is one of the most important food crops in the world. With increasing world demand for food crops, there is an urgent need to develop new cultivars that have enhanced performance with regard to yield, disease resistance, and so on. Wild rice is expected to provide useful genetic resources that could improve the present cultivated species. However, the quantity and quality of these unexplored resources remain unclear. Recent accumulation of the genomic information of both cultivated and wild rice species allows for their comparison at the molecular level. Here, we compared the genome sequence of Oryza sativa ssp. japonica with sets of bacterial artificial chromosome end sequences (BESs from two wild rice species, O. rufipogon and O. nivara, and an African rice species, O. glaberrima. Results We found that about four to five percent of the BESs of the two wild rice species and about seven percent of the African rice could not be mapped to the japonica genome, suggesting that a substantial number of genes have been lost in the japonica rice lineage; however, their close relatives still possess their counterpart genes. We estimated that during evolution, O. sativa has lost at least one thousand genes that are still preserved in the genomes of the other species. In addition, our BLASTX searches against the non-redundant protein sequence database showed that disease resistance-related proteins were significantly overrepresented in the close relative-specific genomic portions. In total, 235 unmapped BESs of the three relatives matched 83 non-redundant proteins that contained a disease resistance protein domain, most of which corresponded to an NBS-LRR domain. Conclusion We found that the O. sativa lineage appears to have recently experienced massive gene losses following divergence from its wild ancestor. Our results imply that the domestication process accelerated large-scale genomic deletions in the lineage of Asian

  20. Phylogeny and biogeography of North-American wild rice (Zizania L.Poaceae)

    Science.gov (United States)

    The wild-rice genus Zizania includes four species disjunctly distributed in eastern Asia and North America, with three species (Z. aquatica, Z. palustris, and Z. texana) in North America and one (Z. latifolia) in eastern Asia. The phylogeny and biogeography of Zizania were explored using sequences o...

  1. Application of induced mutations and modern technologies for rice improvement at the Philippine Rice Research Institute (PhilRice)

    International Nuclear Information System (INIS)

    Padolina, Thelma F.

    2015-01-01

    The application of mutation techniques, i.e. gamma rays and other physical and chemical mutagens has generated a vast amount of genetic variability and has played a significant role in plant breeding and genetics. The widespread use of mutation techniques in plant breeding programs throughout the world has led to the official release of more than 3000 mutant varieties from different plant species. These varieties provide higher yields, better quality, resistance to diseases and resilience to climate change and variability. In the Philippine Rice Research Institute (PhilRice), classical induced mutagenesis and/or in combination with modern technologies as an important tool in rice breeding have been widely utilized by breeders. These recent advances offered new and exciting challenges for the development of new varieties. Moreover, it has the advantage of free regulatory restrictions imposed on genetically modified organisms. To date, high generation of new varieties, elite lines and pre-breeding materials have been derived from chemical and physical mutagenesis, another culture, in vitro mutagenesis, and molecular marker technologies. Directly benefitting the farmers are three Philippine released varieties: PSB Rc78 developed through gamma ray induction in year 2000; and NSIC Rc272 (2011) and Rc346 (2013) developed by combination of Co60 induction and another culture technology. These varieties are intended for the lowlands. In the current works, diverse mutant lines and pre-breeding materials of different target traits were generated and are now under evaluation as potential varieties and/or for use in the inbred and hybrid breeding programs. These genetic materials are in the background of traditional and modern rice varieties. Accordingly, for inbreds, mutated traits ranged from changes in morphological traits, yield, maturity, grain quality, nutritional traits, abiotic resistance such as heat, salinity, and drought tolerance, biotic resistance such as bacterial

  2. Processing Conditions, Rice Properties, Health and Environment

    Directory of Open Access Journals (Sweden)

    Nobutaka Nakamura

    2011-06-01

    Full Text Available 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.

  3. Elemental composition of Malawian rice.

    Science.gov (United States)

    Joy, Edward J M; Louise Ander, E; Broadley, Martin R; Young, Scott D; Chilimba, Allan D C; Hamilton, Elliott M; Watts, Michael J

    2017-08-01

    Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic elements including arsenic (As), cadmium (Cd) and lead (Pb). The aim of this study was to determine the mineral composition of rice sampled from farmers' fields and markets in Malawi. Rice was sampled from 18 extension planning areas across Malawi with 21 white (i.e. polished) and 33 brown samples collected. Elemental composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Arsenic speciation was performed using high-performance liquid chromatography (HPLC)-ICP-MS. Concentration of PA was determined using a PA-total phosphorus assay. Median total concentrations (mg kg -1 , dry weight) of elements important for human nutrition in brown and white rice, respectively, were: Ca = 66.5 and 37.8; Cu = 3.65 and 2.49; Fe = 22.1 and 7.2; I = 0.006 and rice samples, respectively, median PA concentrations were 5438 and 1906 mg kg -1 , and median PA:Zn molar ratios were 29 and 13. Concentrations of potentially toxic elements (mg kg -1 , dry weight) in brown and white rice samples, respectively, were: As = 0.030 and 0.006; Cd  ≤ 0.002 and 0.006; Pb = 0.008 and 0.008. Approximately 95 % of As was found to be inorganic As, where this could be quantified. Malawian rice, like the more widely consumed staple grain maize, contains inadequate Ca, I, Se or Zn to meet dietary requirements. Biofortification strategies could significantly increase Se and Zn concentrations and require further investigation. Concentrations of Fe in rice grain varied

  4. 75 FR 56911 - Request for Public Comment on the United States Standards for Rough Rice, Brown Rice for...

    Science.gov (United States)

    2010-09-17

    ... for Rough Rice, Brown Rice for Processing, and Milled Rice AGENCY: Grain Inspection, Packers and... reviewing the United States Standards and grading procedures for Rough Rice, Brown Rice for Processing, and Milled Rice under the Agriculture Marketing Act of 1946 (AMA). Since the standards were last revised...

  5. Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

    OpenAIRE

    Imam, Mustapha Umar; Musa, Siti Nor Asma; Azmi, Nur Hanisah; Ismail, Maznah

    2012-01-01

    Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations inst...

  6. Diversity of global rice markets and the science required for consumer-targeted rice breeding

    Science.gov (United States)

    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 ...

  7. Use of radiation disinfestation in the control of rice insect pests during storage

    International Nuclear Information System (INIS)

    El-Kady, E.A.

    1981-01-01

    Rice weevil (Sitophilus oryzae), red flour beetle (Tribolium castaeneum), saw-toothed grain beetle (Oryzaephilus surinamensis), and flour moth (Ephestia kuehniella) are commonly found in Egyptian stored rice. The aim of this project is to carry out a study of a pilot-scale radiation disinfestation of these rice insect pests in an amount large enough to extrapolate data for later commercial practice. Fumigation treatments with phostoxin, methyl bromide and a combination treatment (methyl bromide + 7.5 krad) were also performed as a comparison to reveal the most effective way to control these rice pests. The most effective of all treatments tested was the 50-krad treatment. Complete sterility for the adults of these pests was obtained after treating rice directly, while complete mortality was reached within 30-60 days. Regarding fumigation treatments - phostoxin, methylbromide and combined treatment (methylbromide + 7.5 krad), the living stages of the four insect pests in rice varied during the storage period. However, the combination treatment gave the best results. Adults of the three Coleopteran species appeared in rice after four months because the 7.5-krad dose was not enough to kill the eggs which might have been laid by young females before being killed by fumigants. (author)

  8. Multi Stakeholders' Attitudes toward Bt rice in Southwest, Iran: Application of TPB and Multi Attribute Models.

    Science.gov (United States)

    Ghoochani, Omid M; Ghanian, Mansour; Baradaran, Masoud; Azadi, Hossein

    2017-03-01

    Organisms that have been genetically engineered and modified (GM) are referred to as genetically modified organisms (GMOs). Bt crops are plants that have been genetically modified to produce certain proteins from the soil bacteria Bacillus thuringiensis (Bt), which makes these plants resistant to certain lepidopteran and coleopteran species. Genetically Modified (GM) rice was produced in 2006 by Iranian researchers from Tarom Mowla'ii and has since been called 'Bt rice'. As rice is an important source of food for over 3 billion inhabitants on Earth, this study aims to use a correlational survey in order to shed light on the predicting factors relating to the extent of stakeholders' behavioral intentions towards Bt rice. It is assumed and the results confirm that "attitudes toward GM crops" can be used as a bridge in the Attitude Model and the Behavioral Intention Model in order to establish an integrated model. To this end, a case study was made of the Southwest part of Iran in order to verify this research model. This study also revealed that as a part of the integrated research framework in the Behavior Intention Model both constructs of attitude and the subjective norm of the respondents serve as the predicting factors of stakeholders' intentions of working with Bt rice. In addition, the Attitude Model, as the other part of the integrated research framework, showed that the stakeholders' attitudes toward Bt rice can only be determined by the perceived benefits (e.g. positive outcomes) of Bt rice.

  9. Mechanism and capacities of reducing ecological cost through rice-duck cultivation.

    Science.gov (United States)

    Long, Pan; Huang, Huang; Liao, Xiaolan; Fu, Zhiqiang; Zheng, Huabin; Chen, Aiwu; Chen, Can

    2013-09-01

    Rice-duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. The duck's secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich species diversity and improve the field environment. The rice-duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers. The control effects can be up to 98.47% and 100% respectively; it also has effects on the control of Chilo suppressalis, Tryporyza incertulas and the rice leafrollers. Notable control results are found on sheath blight, while the effects on other diseases are about 50%. Harm from weeds is placed under primary control; prevention of weeds is sequenced by broadleaf weeds > sedge weeds > Gramineae weeds. Contents of soil organic matter, N, P and K are improved by the system; nutrient utilization is accelerated, resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1-2% and duck fodder is saved in this system. There is also an obvious economic benefit. Compared to conventional rice cultivation, rice-duck cultivation shows great benefits to ecologic cost and economic income. © 2013 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  10. Rice varieties in relation to rice bread quality.

    Science.gov (United States)

    Han, Hye Min; Cho, Jun Hyeon; Kang, Hang Won; Koh, Bong Kyung

    2012-05-01

    It is difficult to predict rice bread quality only from the amylose content (AC) or dough characteristics of new lines produced by rice breeding programmes. This study investigated the AC relative to bread baking quality of rice varieties developed in Korea, and identified specific characteristics that contribute to rice bread quality. Manmibyeo, Jinsumi, Seolgaeng and Hanareumbyeo were classified as low AC, YR24088 Acp9, Suweon517, Chenmaai and Goamibyeo as intermediate AC and Milyang261 as high AC. Suweon517, Milyang261 and Manmibyeo had a high water absorption index (WAI), while Goamibyeo, YR24088 Acp9, Jinsumi, Seolgaeng, Hanareumbyeo and Chenmaai had a low WAI. The gelatinisation enthalpy of flour varied from 9.2 J g(-1) in Milyang261 to 14.8 J g(-1) in YR24088 Acp9. After 7 days of storage the rate of flour retrogradation and crumb firmness were weakly correlated, with the exception of Jinsumi. Bread volumes of Jinsumi, Chenmaai, YR24088 Acp9 and Goamibyeo were comparable to that of wheat flour, but the rest were unsuited to bread making because of their low volume and hard crumb texture. Based on volume, texture and crumb firmness ratio, Chenmaai and Goamibyeo were the most appropriate varieties for making bread. An intermediate AC and low WAI were the primary indicators of rice bread flour quality. Copyright © 2011 Society of Chemical Industry.

  11. Deciphering the role of a miRNA in rice domestication

    Directory of Open Access Journals (Sweden)

    Swetha Chenna

    2017-10-01

    Full Text Available MicroRNAs (miRNAs are a class of 21 nt non-coding small RNAs (sRNAs produced from endogenously expressed MIR genes. miRNAs are mostly involved in development and disease resistance. We are interested in identifying key miRNAs that are differentially expressed among wild and cultivated rice species. Analysis of sRNA datasets from two wild species (O. nivara and O. rufipogon and one cultivated species of rice (O. sativa var. indica Pusa Basmati-1, revealed a surprisingly higher abundance of small RNAs originating from Chromosome 2 in wild rice species. This locus codes for a novel 22 nt miRNA. This novel miRNA was found to be highly abundant in flag leaf of wild species, a tissue that usually provides 70% of energy required for grain filling. This miRNA targets a group of proteins (Os03g0273200, Os01g0827300, Os01g0850700, Os11g0708100 and Os01g0842500 which are involved in secondary metabolite production, although a functional significance of this interaction has not been understood. The expression of these targets also differs across the species. Typical of 22 nt miRNAs, the identified miRNA also triggers a secondary cascade silencing by producing small interfering RNAs (siRNAs from target mRNAs in O. nivara. These secondary siRNAs are observed only among wild rice species but not in cultivated rice. Currently we are using a range of genetic, biochemical and molecular techniques to understand role of this novel miRNA in domestication of rice.

  12. Photoperiod shift effects on yield characteristics of rice

    Science.gov (United States)

    Volk, G. M.; Mitchell, C. A.

    1995-01-01

    Edible yield must be maximized for each crop species selected for inclusion in the Controlled Ecological Life-Support System (CELSS) proposed by NASA to support long-term manned space missions. In a greenhouse study aimed at increasing biomass partitioning to rice (Oryza sativa L.) grain, plants of the high yielding semi-dwarf rice cultivar Ai-Nan-Tsao were started in pots under 8-h photoperiods at a density of 212 plants m-2. After different periods of time under 8-h photoperiods, pots were switched to continuous light for the remainder of the cropping cycle. Continuous light did not delay time to first panicle emergence (60 d) or time to harvest (83 d). There was a positive correlation between the length of continuous light treatments and nongrain biomass. Grain yield (1.6 +/- 0.2 g plant-1) did not increase in continuous light. Yield-efficiency rate (grain weight per length of cropping cycle, canopy volume, and weight of nongrain shoot biomass) was used to compare treatments. Small Ai-Nan-Tsao rice canopies grown under 8-h photoperiods were more efficient producers of grain than canopies grown under continuous light for a portion of the rice cropping cycle.

  13. Combined Mass Spectrometry-Based Metabolite Profiling of Different Pigmented Rice (Oryza sativa L. Seeds and Correlation with Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Ga Ryun Kim

    2014-09-01

    Full Text Available Nine varieties of pigmented rice (Oryza sativa L. seeds that were black, red, or white were used to perform metabolite profiling by using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS and gas chromatography (GC TOF-MS, to measure antioxidant activities. Clear grouping patterns determined by the color of the rice seeds were identified in principle component analysis (PCA derived from UPLC-Q-TOF-MS. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimer, proanthocyanidin trimer, apigenin-6-C-glugosyl-8-C-arabiboside, tricin-O-rhamnoside-O-hexoside, and lipids were identified as significantly different secondary metabolites. In PCA score plots derived from GC-TOF-MS, Jakwangdo (JKD and Ilpoom (IP species were discriminated from the other rice seeds by PC1 and PC2. Valine, phenylalanine, adenosine, pyruvate, nicotinic acid, succinic acid, maleic acid, malonic acid, gluconic acid, xylose, fructose, glucose, maltose, and myo-inositol were significantly different primary metabolites in JKD species, while GABA, asparagine, xylitol, and sucrose were significantly distributed in IP species. Analysis of antioxidant activities revealed that black and red rice seeds had higher activity than white rice seeds. Cyanidin-3-glucoside, peonidin-3-glucoside, proanthocyanidin dimers, proanthocyanidin trimers, and catechin were highly correlated with antioxidant activities, and were more plentiful in black and red rice seeds. These results are expected to provide valuable information that could help improve and develop rice-breeding techniques.

  14. A Non-destructive and Continuous Measurement of Gelatinization of Rice in Rice Cooking Process

    OpenAIRE

    Hagura, Yoshio; Suzuki, Kanichi

    2002-01-01

    A non-destructive and continuous method to measure gelatinization of rice samples in a rice-water system during rice cooking process was examined. An aluminum pot and a lid of a rice cooker were used as two electrode plates, and changes in dielectric properties (capacitance : C, and dielectric dissipation factor : tan δ) of the samples in the rice cooking process were measured by a capacitance meter. Differential scanning calorimetry (DSC) was used to measure gelatinization enthalpy and to de...

  15. Effect of Rice bran on the Quality of Rice Flour Breads (Gluten-free)

    OpenAIRE

    仲上, 晴世; 矢部, えん; Haruyo, Nakagami; En, Yabe

    2016-01-01

    Over recent years progress has been made in the development of substitute foods for allergy patients. One such is rice flour bread. However, typically rice flour bread uses polysaccharide thickener in substitution for the gluten in wheat. Most polysaccharide thickeners are of dietary fiber origin, and the nutritive value is poor. Therefore, in this study, I made rice flour bread adding rice bran in place of polysaccharide thickener. Various nutrients are included in rice bran, including vitam...

  16. Community-wise evaluation of rice beer prepared by some ethnic tribes of Tripura

    Directory of Open Access Journals (Sweden)

    Sushanta Ghosh

    2016-12-01

    Full Text Available Tripura is inhabited by many indigenous communities having unique ethno-socio-cultural lifestyle with age-old rice beer brewing techniques using wild herbs and local rice varieties popularly known as chuwak or zu. The present study is focused on comparative evaluation of brewing methods and nutritional aspects of rice beer among Debbarma, Jamatia, Koloi, and Molsom tribes of Tripura. Sample ingredients and plant species are properly identified before reporting. Rice beer is also prepared in laboratory conditions for comparative studies of qualitative and quantitative aspects. Thirteen different plant species are used by these four tribes for preparation of starter cultures using soaked rice flour. Markhamia stipulate (Wall. Seem. is common to all communities for starter cake preparation. Litsea monopetala (Roxb. Pers. is used by all three communities except Jamatia. The use of Ananus comosus Mill. is common among Debbarma and Jamatia tribes, whereas that of Artocarpus heterophyllus Lam. is common among Molsom and Koloi tribes. However, Aporusa diocia (Roxb. Muell., Combretum indicum (L. DeFilipps., and Citrus sinensis (L. Osbeck. are used only by Debbarma tribe for unique tangy flavor. The physicochemical properties of rice beer varied within tribes for its moisture content, carbohydrate content, reducing sugar, and alcohol percentage. The concentration of alcohol increases with aging and prolonged fermentation. The plants reported here are also reported for having nutritional and medicinal benefits for the metabolic stability in humans, which make the process more prospective for commercialization if a standard for maintaining a quality and associated risk can be determined.

  17. Crown sheath rot of rice: host-range and varietal resistance to Gaeumannomyces graminis var. graminis

    Directory of Open Access Journals (Sweden)

    Cecília do Nascimento Peixoto

    2014-09-01

    Full Text Available Several gramineous plants occurring in rice fields show symptoms of crown sheath rot of rice, caused by Gaeumannomyces graminis var. graminis (Ggg, under natural conditions of infection. The pathogenicity of the Ggg-a 01 isolate, collected from rice, was tested on seven grass species and eight cereals, under greenhouse conditions, in order to get information on host-range and resistance of rice genotypes to crown sheath rot. The inoculation tests showed that the rice isolate was pathogenic to weeds such as Echinochloa crusgalli, Pennisetum setosum, Brachiaria sp., Digitaria horizontalis, Brachiaria plantaginea, Eleusine indica and Cenchrus echinatus, and that these species are potential hosts to the pathogen. Winter cereals such as wheat, oat, rye, barley and triticale, as well as sorghum, maize and millet, presented different degrees of susceptibility to the Ggg-a isolate. Significant differences were observed in relation to lesion height and production of hyphopodia and perithecia on culms. Perithecia were not observed on millet, sorghum, southern sandbur and maize. The resistance of 58 upland rice genotypes was tested, and the SCIA16 and SCIA08 genotypes presented lesion height significantly smaller, being considered resistant, when compared to the highly susceptible CNAS10351 genotype.

  18. Sodium bicarbonate absorption and anabolism by detatched root of young paddy rice, corn and wheat plants

    International Nuclear Information System (INIS)

    Yamakawa, Takeo; Yamada, Yoshio

    1985-01-01

    This work is aimed at investigating species-to-species difference in the capability of absorption and anabolism through the root and examining the effects of sodium bicarbonate on the capability. Roots detatched from young plants of paddy rice, corn and wheat are used as the samples. The respiratory rate and anabolic rate of the detatched roots are measured by using the 14 C tracer. It is found that paddy rice whows the greatest initial anabolic rate, while the rates of corn and wheat are 14 - 30 % of that of paddy rice. The initial anabolic rate is almost independent of the concentration of sodium bicarbonate. The initial absorption rate is greatest in paddy rice, followed by corn (30 - 78 %) and wheat (16 - 21 %). It is also shown that paddy rice has the greatest capability both in anabolism and absorption. The anabolism and absorption capabilities of corn are 17 - 29 % and 31 - 80 % of those of paddy rice, respectively. The corresponding values of wheat are 16 - 38 % and 24 - 66 %. Sidium bicarbonate has little effect on the anabolism capability, while the absorption capability is affected above a high concentration of 50 mM. (Nogami, K.)

  19. Development of a simple, sensitive and inexpensive ion-pairing cloud point extraction approach for the determination of trace inorganic arsenic species in spring water, beverage and rice samples by UV-Vis spectrophotometry.

    Science.gov (United States)

    Gürkan, Ramazan; Kır, Ufuk; Altunay, Nail

    2015-08-01

    The determination of inorganic arsenic species in water, beverages and foods become crucial in recent years, because arsenic species are considered carcinogenic and found at high concentrations in the samples. This communication describes a new cloud-point extraction (CPE) method for the determination of low quantity of arsenic species in the samples, purchased from the local market by UV-Visible Spectrophotometer (UV-Vis). The method is based on selective ternary complex of As(V) with acridine orange (AOH(+)) being a versatile fluorescence cationic dye in presence of tartaric acid and polyethylene glycol tert-octylphenyl ether (Triton X-114) at pH 5.0. Under the optimized conditions, a preconcentration factor of 65 and detection limit (3S blank/m) of 1.14 μg L(-1) was obtained from the calibration curve constructed in the range of 4-450 μg L(-1) with a correlation coefficient of 0.9932 for As(V). The method is validated by the analysis of certified reference materials (CRMs). Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Genetic structure and diversity of indigenous rice (Oryza sativa) varieties in the Eastern Himalayan region of Northeast India.

    Science.gov (United States)

    Choudhury, Baharul; Khan, Mohamed Latif; Dayanandan, Selvadurai

    2013-12-01

    The Eastern Himalayan region of Northeast (NE) India is home to a large number of indigenous rice varieties, which may serve as a valuable genetic resource for future crop improvement to meet the ever-increasing demand for food production. However, these varieties are rapidly being lost due to changes in land-use and agricultural practices, which favor agronomically improved varieties. A detailed understanding of the genetic structure and diversity of indigenous rice varieties is crucial for efficient utilization of rice genetic resources and for developing suitable conservation strategies. To explore the genetic structure and diversity of rice varieties in NE India, we genotyped 300 individuals of 24 indigenous rice varieties representing sali, boro, jum and glutinous types, 5 agronomically improved varieties, and one wild rice species (O. rufipogon) using seven SSR markers. A total of 85 alleles and a very high level of gene diversity (0.776) were detected among the indigenous rice varieties of the region. Considerable level of genetic variation was found within indigenous varieties whereas improved varieties were monoporphic across all loci. The comparison of genetic diversity among different types of rice revealed that sali type possessed the highest gene diversity (0.747) followed by jum (0.627), glutinous (0.602) and boro (0.596) types of indigenous rice varieties, while the lowest diversity was detected in agronomically improved varieties (0.459). The AMOVA results showed that 66% of the variation was distributed among varieties indicating a very high level of genetic differentiation in rice varieties in the region. Two major genetically defined clusters corresponding to indica and japonica groups were detected in rice varieties of the region. Overall, traditionally cultivated indigenous rice varieties in NE India showed high levels of genetic diversity comparable to levels of genetic diversity reported from wild rice populations in various parts of the

  1. FLUORIDE LEVELS IN COMMERCIALLY AVAILABLE RICE IN ...

    African Journals Online (AJOL)

    Preferred Customer

    2013-05-05

    May 5, 2013 ... Rice is one of the commonly consumed cereals for more than half of the ... also used as flour, for making rice wine, as ingredient for beer and liquor, ... Fluoride is a necessary element to human health, and a moderate amount of fluoride intake ... For Ethiopian red rice (ERR) Fogera was selected to collect.

  2. Impact of bio-processing on rice

    Directory of Open Access Journals (Sweden)

    ANCA NICOLAU

    2011-07-01

    Full Text Available The usual way of preparing rice is boiling, thermal process that gives it a lower digestibility as compared to instantiation, extrusion or expandation. Having in view this fact, the possibility to biotechnologically improve the boiled rice digestibility was investigated in a laboratory study. In this respect, boiled rice wassolid state fermented using a strain of Saccharomycopsis fibuligera, an amylase producing yeast originating from ragi. Fermented rice was then analyzed from the point of view of its content in easily assimilable sugars, protein, amino-acids, phosphorus and vitamins from B group. Biochemical analyses revealed that the fermented rice has a ten times higher content of reducing sugars than boiled rice, due to starch hydrolysis, while chromatographic studies proved that the fermented rice contains glucose, maltose, maltotriose and maltotetrose that are easily assimilable carbohydrates.Fermented rice has a protein content that is two times higher than that of boiled rice because it contains the yeast biomass, and is enriched in vitamins from B group (B1, B2, and B6 that are synthesized by the yeast. Inorganic phosphorus present in rice doubles its concentration in fermented rice, which means thatphosphorus bioavailability is increased.The sensorial profile of boiled rice is also improved by fermentation.This study proves the possibility to have a processing method which is relatively cheap, practical and of which the resulting product has good nutritive qualities and does not pose safety problems due to pure culture utilization as starter.

  3. PICTORIAL INTERLUDES Flake-shaped rice bodies

    African Journals Online (AJOL)

    removing the rice bodies and the bursa.3. In summary: rice bodies can occur without underlying systemic disorder, have different shapes and sizes, and have specific signal characteristics on. MRI that allow discrimination from synovial chondromatosis. 1. Cheung HS, Ryan LM, Kozin F, McCarty DJ. Synovial origins of rice ...

  4. New market opportunities for rice grains

    Science.gov (United States)

    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 ...

  5. Arsenic in rice: A cause for concern

    DEFF Research Database (Denmark)

    Hojsak, Iva; Braegger, Christian; Bronsky, Jiri

    2015-01-01

    Inorganic arsenic intake is likely to affect long-term health. High concentrations are found in some rice-based foods and drinks widely used in infants and young children. In order to reduce exposure we recommend avoidance of rice drinks for infants and young children. For all rice products, stri...

  6. Consumer preference mapping for rice product concepts

    NARCIS (Netherlands)

    Suwannaporn, P.; Linnemann, A.R.; Chaveesuk, R.

    2008-01-01

    Purpose - Rice consumption per capita in many Asian countries is decreasing constantly, but American and European citizens are eating more rice nowadays. A preference study among consumers was carried out with the aim of determining new rice product characteristics in order to support export of Thai

  7. Microbial-driven arsenic cycling in rice paddies amended with monosodium methanearsonate

    Science.gov (United States)

    Maguffin, S. C.; McClung, A.; Rohila, J. S.; Derry, L. A.; Huang, R.; Reid, M. C.

    2017-12-01

    Rice consumption is the second largest contributor to human arsenic exposure worldwide and is linked to many serious diseases. Because rice is uniquely adapted for agricultural production under flooded soils, arsenic species solubilized in such environments can be effectively transported into plant tissue via root transporters. Through this process, both inorganic and organic (methylated) arsenic species can accumulate to problematic concentrations and may affect grain yield as well as crop value. The distribution of these species in plant tissue is determined by arsenic sources, as well as enzymatic redox and methylation-demethylation reactions in soils and pore water. Historic use of organoarsenic-based pesticides in US agriculture may provide an enduring source of arsenic in rice paddies. However, it is unclear how persistent these organic species are in the adsorbed phase or how available they remain to rice cultivars throughout the growing season. We conducted a field experiment in a 2x2 factorial design examining the effects of irrigation methods (continuous flooding and alternate wetting and drying) and monosodium methanearsonate (MSMA) application on the abundance and speciation of arsenic in pore water, soil, and rice plant tissues. We monitored arsenic speciation and partitioning between these reservoirs at semi-weekly to semi-monthly frequencies. Pore water arsenic speciation was determined using LC-ICP-MS, and X-ray absorption near-edge structure (XANES) analysis was employed to speciate the arsenic within solid-phase soil and plant tissue throughout the growing season. These data help clarify the role of two irrigation methods and MSMA amendments for arsenic bioavailability and speciation in rice. Furthermore, the study illuminates the significance of microbial metabolism in the reapportionment of arsenic within the soil-plant-water system and its impact on arsenic levels in rice grains.

  8. Comparative genome analysis of rice-pathogenic Burkholderia provides insight into capacity to adapt to different environments and hosts.

    Science.gov (United States)

    Seo, Young-Su; Lim, Jae Yun; Park, Jungwook; Kim, Sunyoung; Lee, Hyun-Hee; Cheong, Hoon; Kim, Sang-Mok; Moon, Jae Sun; Hwang, Ingyu

    2015-05-06

    In addition to human and animal diseases, bacteria of the genus Burkholderia can cause plant diseases. The representative species of rice-pathogenic Burkholderia are Burkholderia glumae, B. gladioli, and B. plantarii, which primarily cause grain rot, sheath rot, and seedling blight, respectively, resulting in severe reductions in rice production. Though Burkholderia rice pathogens cause problems in rice-growing countries, comprehensive studies of these rice-pathogenic species aiming to control Burkholderia-mediated diseases are only in the early stages. We first sequenced the complete genome of B. plantarii ATCC 43733T. Second, we conducted comparative analysis of the newly sequenced B. plantarii ATCC 43733T genome with eleven complete or draft genomes of B. glumae and B. gladioli strains. Furthermore, we compared the genome of three rice Burkholderia pathogens with those of other Burkholderia species such as those found in environmental habitats and those known as animal/human pathogens. These B. glumae, B. gladioli, and B. plantarii strains have unique genes involved in toxoflavin or tropolone toxin production and the clustered regularly interspaced short palindromic repeats (CRISPR)-mediated bacterial immune system. Although the genome of B. plantarii ATCC 43733T has many common features with those of B. glumae and B. gladioli, this B. plantarii strain has several unique features, including quorum sensing and CRISPR/CRISPR-associated protein (Cas) systems. The complete genome sequence of B. plantarii ATCC 43733T and publicly available genomes of B. glumae BGR1 and B. gladioli BSR3 enabled comprehensive comparative genome analyses among three rice-pathogenic Burkholderia species responsible for tissue rotting and seedling blight. Our results suggest that B. glumae has evolved rapidly, or has undergone rapid genome rearrangements or deletions, in response to the hosts. It also, clarifies the unique features of rice pathogenic Burkholderia species relative to other

  9. Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice.

    Science.gov (United States)

    Wang, Hongru; Vieira, Filipe G; Crawford, Jacob E; Chu, Chengcai; Nielsen, Rasmus

    2017-06-01

    The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon , are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genomes consisting of 203 domesticated and 435 wild rice accessions. We show that most modern wild rice is heavily admixed with domesticated rice through both pollen- and seed-mediated gene flow. In fact, much presumed wild rice may simply represent different stages of feralized domesticated rice. In line with this hypothesis, many presumed wild rice varieties show remnants of the effects of selective sweeps in previously identified domestication genes, as well as evidence of recent selection in flowering genes possibly associated with the feralization process. Furthermore, there is a distinct geographical pattern of gene flow from aus , indica , and japonica varieties into colocated wild rice. We also show that admixture from aus and indica is more recent than gene flow from japonica , possibly consistent with an earlier spread of japonica varieties. We argue that wild rice populations should be considered a hybrid swarm, connected to domesticated rice by continuous and extensive gene flow. © 2017 Wang et al.; Published by Cold Spring Harbor Laboratory Press.

  10. Effects of Extraction Methods on Phytochemicals of Rice Bran Oils Produced from Colored Rice.

    Science.gov (United States)

    Mingyai, Sukanya; Srikaeo, Khongsak; Kettawan, Aikkarach; Singanusong, Riantong; Nakagawa, Kiyotaka; Kimura, Fumiko; Ito, Junya

    2018-02-01

    Rice bran oil (RBO) especially from colored rice is rich in phytochemicals and has become popular in food, cosmetic, nutraceutical and pharmaceutical applications owing to its offering health benefits. This study determined the contents of phytochemicals including oryzanols, phytosterols, tocopherols (Toc) and tocotrienols (T3) in RBOs extracted using different methods namely cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Two colored rice, Red Jasmine rice (RJM, red rice) and Hom-nin rice (HN, black rice), were studied in comparison with the popular Thai fragrant rice Khao Dawk Mali 105 (KDML 105, white rice). RBOs were found to be the rich source of oryzanols, phytosterols, Toc and T3. Rice varieties had a greater effect on the phytochemicals concentrations than extraction methods. HN rice showed the significantly highest concentration of all phytochemicals, followed by RJM and KDML 105 rice, indicating that colored rice contained high concentration of phytochemicals in the oil than non-colored rice. The RBO samples extracted by the CPE method had a greater concentration of the phytochemicals than those extracted by the SC-CO 2 and SE methods, respectively. In terms of phytochemical contents, HN rice extracted using CPE method was found to be the best.

  11. Geographic and Research Center Origins of Rice Resistance to Asian Planthoppers and Leafhoppers: Implications for Rice Breeding and Gene Deployment

    Directory of Open Access Journals (Sweden)

    Finbarr G. Horgan

    2017-09-01

    Full Text Available This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs indicated a clade of highly resistant varieties from South Asia with two further South Asian clades of moderate resistance. Greenhouse bioassays indicated that planthoppers can develop virulence against multiple resistance genes including genes introgressed from wild rice species. Nilaparvata lugens populations from Punjab (India and the Mekong Delta (Vietnam were highly virulent to a range of key resistance donors irrespective of variety origin. Sogatella furcifera populations were less virulent to donors than N. lugens; however, several genes for resistance to S. furcifera are now ineffective in East Asia. A clade of International Rice Research Institute (IRRI-bred varieties and breeding lines, without identified leafhopper-resistance genes, were highly resistant to the green leafhopper, Nephotettix virescens. Routine phenotyping during breeding programs likely maintains high levels of quantitative resistance to leafhoppers. We discuss these results in the light of breeding and deploying resistant rice in Asia.

  12. Field performance and genetic makeup of RU1001161, a good quality selection from crosses between weed-suppressive indica rice and commercial U.S. southern long grains

    Science.gov (United States)

    Sustainable, economically viable weed control is an ongoing challenge in U.S. rice production, particularly in light of increased resistance to herbicides in populations of Echinochloa crus-galli (barnyardgrass) and other weed species. Indica rice lines such as PI 312777 and PI 338046 have been sho...

  13. High-resolution mapping of Rsn1, a locus controlling sensitivity of rice to a necrosis-inducing phytotoxin from Rhizoctonia solani AG1-IA

    Science.gov (United States)

    Rhizoctonia solani is a necrotrophic fungal pathogen that causes disease on all major crop-plant species. Anastomosis group 1-IA is the causal agent of sheath blight of rice (Oryza sativa), one of the most important rice diseases worldwide. R. solani AG-IA produces a necrosis-inducing phytotoxin a...

  14. The Effect of Dietary Replacement of Ordinary Rice with Red Yeast Rice on Nutrient Utilization, Enteric Methane Emission and Rumen Archaeal Diversity in Goats.

    Directory of Open Access Journals (Sweden)

    L Z Wang

    Full Text Available Twenty castrated Boer crossbred goats were used in the present study with two treatments to examine the effect of dietary replacement of ordinary rice with red yeast rice on nutrient utilization, enteric methane emission and ruminal archaea structure and composition. Two treatment diets contained (DM basis 70.0% of forage, 21.8% of concentrates and 8.2% of either ordinary rice (control or red yeast rice (RYR. Nutrient utilization was measured and enteric methane emissions were determined in respiration chambers. Results showed that RYR had significantly lower digestibility of N and organic matter compared to control group. However, feeding red yeast rice did not affect N retention as g/d or a proportion of N intake, and reduced heat production as MJ/d or as a proportion of metabolizable energy intake, thus leading to a higher proportion of metabolizable energy intake to be retained in body tissue. RYR also had significantly lower methane emissions either as g/d, or as a proportion of feed intake. Although feeding red yeast rice had no negative effect on any rumen fermentation variables, it decreased serum contents of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol. In the present study, 75616 archaeal sequences were generated and clustered into 2364 Operational Taxonomic Units. At the genus level, the predominant archaea in the rumen of goats was Methanobrevibacter, which was significantly inhibited with the supplementation of red yeast rice. In conclusion, red yeast rice is a potential feed ingredient for mitigation of enteric methane emissions of goats. However, caution should be taken when it is used because it may inhibit the digestibility of some nutrients. Further studies are required to evaluate its potential with different diets and animal species, as well as its effects on animal health and food safety.

  15. The role of Bh4 in parallel evolution of hull colour in domesticated and weedy rice.

    Science.gov (United States)

    Vigueira, C C; Li, W; Olsen, K M

    2013-08-01

    The two independent domestication events in the genus Oryza that led to African and Asian rice offer an extremely useful system for studying the genetic basis of parallel evolution. This system is also characterized by parallel de-domestication events, with two genetically distinct weedy rice biotypes in the US derived from the Asian domesticate. One important trait that has been altered by rice domestication and de-domestication is hull colour. The wild progenitors of the two cultivated rice species have predominantly black-coloured hulls, as does one of the two U.S. weed biotypes; both cultivated species and one of the US weedy biotypes are characterized by straw-coloured hulls. Using Black hull 4 (Bh4) as a hull colour candidate gene, we examined DNA sequence variation at this locus to study the parallel evolution of hull colour variation in the domesticated and weedy rice system. We find that independent Bh4-coding mutations have arisen in African and Asian rice that are correlated with the straw hull phenotype, suggesting that the same gene is responsible for parallel trait evolution. For the U.S. weeds, Bh4 haplotype sequences support current hypotheses on the phylogenetic relationship between the two biotypes and domesticated Asian rice; straw hull weeds are most similar to indica crops, and black hull weeds are most similar to aus crops. Tests for selection indicate that Asian crops and straw hull weeds deviate from neutrality at this gene, suggesting possible selection on Bh4 during both rice domestication and de-domestication. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  16. Isotope studies on rice fertilization

    International Nuclear Information System (INIS)

    1978-01-01

    The aim of the report is to provide practical information on the efficient utilization of nitrogen fertilizers in rice production. Results obtained from field investigations during the years 1970 to 1974 in ten countries (Bangladesh, Burma, Indonesia, Republic of Korea, Sri Lanka, Taiwan, Thailand, Vietnam, India, Philippines), using 15 N-labelled nitrogen fertilizers (ammonium sulfate, urea) are given. The experiments, which were conducted both during the dry and wet seasons, included comparison of varieties, effect of placement, source and time of nitrogen fertilizer application on the yield and quality of rice. The data from the project is presented in table form. In most of the experiments, the addition of nitrogen increased the rice grain yield. The role of soil nitrogen vs. fertilizer nitrogen is compared, and it is concluded that the physiological growth stage at which fertilizer-derived nitrogen is absorbed is of great importance

  17. Iron biofortification of Myanmar rice

    Directory of Open Access Journals (Sweden)

    May Sann Aung

    2013-05-01

    Full Text Available Iron (Fe deficiency causes 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 and/or 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.

  18. Histology of two rice bodies isolated from the stifle of an adult draught horse stallion.

    Science.gov (United States)

    Schneider, Nicole; Heimann, Marianne; Lejeune, Jean-Philippe; Verwilghen, Denis R V G; Deby-Dupont, Ginette P; Serteyn, Didier A

    2006-03-01

    In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia.

  19. Dolce Vita in the Rice Paddy - Characterization of weedy rice groups in Northern Italy and investigation of their evolutionary origins

    OpenAIRE

    Grimm, Annabelle

    2014-01-01

    The thesis deals with the topic of the invasive rice form called weedy rice or red rice. Studies focused on the geographical area of Italy. Different populations of weedy rice in Italy were genetically characterized. The evolutionary origins of different weedy rice groups were investigated using molecular, morphological and physiological methods. Invasion of wild rice as well as de-domestication of cultivars could be identified as evolutionary sources of weedy rice in Northern Italy.

  20. Small brown planthopper resistance loci in wild rice (Oryza officinalis).

    Science.gov (United States)

    Zhang, Weilin; Dong, Yan; Yang, Ling; Ma, Bojun; Ma, Rongrong; Huang, Fudeng; Wang, Changchun; Hu, Haitao; Li, Chunshou; Yan, Chengqi; Chen, Jianping

    2014-06-01

    Host-plant resistance is the most practical and economical approach to control the rice planthoppers. However, up to date, few rice germplasm accessions that are resistant to the all three kinds of planthoppers (1) brown planthopper (BPH; Nilaparvata lugens Stål), (2) the small brown planthopper (SBPH; Laodelphax striatellus Fallen), and (3) the whitebacked planthopper (WBPH, Sogatella furcifera Horvath) have been identified; consequently, the genetic basis for host-plant broad spectrum resistance to rice planthoppers in a single variety has been seldom studied. Here, one wild species, Oryza officinalis (Acc. HY018, 2n = 24, CC), was detected showing resistance to the all three kinds of planthoppers. Because resistance to WBPH and BPH in O. officinalis has previously been reported, the study mainly focused on its SBPH resistance. The SBPH resistance gene(s) was (were) introduced into cultivated rice via asymmetric somatic hybridization. Three QTLs for SBPH resistance detected by the SSST method were mapped and confirmed on chromosomes 3, 7, and 12, respectively. The allelic/non-allelic relationship and relative map positions of the three kinds of planthopper resistance genes in O. officinalis show that the SBPH, WBPH, and BPH resistance genes in O. officinalis were governed by multiple genes, but not by any major gene. The data on the genetics of host-plant broad spectrum resistance to planthoppers in a single accession suggested that the most ideally practical and economical approach for rice breeders is to screen the sources of broad spectrum resistance to planthoppers, but not to employ broad spectrum resistance gene for the management of planthoppers. Pyramiding these genes in a variety can be an effective way for the management of planthoppers.

  1. Objective evaluation of whiteness of cooked rice and rice cakes using a portable spectrophotometer.

    Science.gov (United States)

    Goto, Hajime; Asanome, Noriyuki; Suzuki, Keitaro; Sano, Tomoyoshi; Saito, Hiroshi; Abe, Yohei; Chuba, Masaru; Nishio, Takeshi

    2014-03-01

    The whiteness of cooked rice and rice cakes was evaluated using a portable spectrophotometer with a whiteness index (WI). Also, by using boiled rice for measurement of Mido values by Mido Meter, it was possible to infer the whiteness of cooked rice without rice cooking. In the analysis of varietal differences of cooked rice, 'Tsuyahime', 'Koshihikari' and 'Koshinokaori' showed high whiteness, while 'Satonoyuki' had inferior whiteness. The whiteness of rice cakes made from 'Koyukimochi' and 'Dewanomochi' was higher than the whiteness of those made from 'Himenomochi' and 'Koganemochi'. While there was a significant correlation (r = 0.84) between WI values and whiteness scores of cooked rice by the sensory test, no correlation was detected between the whiteness scores and Mido values, indicating that the values obtained by a spectrophotometer differ from those obtained by a Mido Meter. Thus, a spectrophotometer may be a novel device for measurement of rice eating quality.

  2. RiceAtlas, a spatial database of global rice calendars and production.

    Science.gov (United States)

    Laborte, Alice G; Gutierrez, Mary Anne; Balanza, Jane Girly; Saito, Kazuki; Zwart, Sander J; Boschetti, Mirco; Murty, M V R; Villano, Lorena; Aunario, Jorrel Khalil; Reinke, Russell; Koo, Jawoo; Hijmans, Robert J; Nelson, Andrew

    2017-05-30

    Knowing where, when, and how much rice is planted and harvested is crucial information for understanding the effects of policy, trade, and global and technological change on food security. We developed RiceAtlas, a spatial database on the seasonal distribution of the world's rice production. It consists of data on rice planting and harvesting dates by growing season and estimates of monthly production for all rice-producing countries. Sources used for planting and harvesting dates include global and regional databases, national publications, online reports, and expert knowledge. Monthly production data were estimated based on annual or seasonal production statistics, and planting and harvesting dates. RiceAtlas has 2,725 spatial units. Compared with available global crop calendars, RiceAtlas is nearly ten times more spatially detailed and has nearly seven times more spatial units, with at least two seasons of calendar data, making RiceAtlas the most comprehensive and detailed spatial database on rice calendar and production.

  3. Labelling of rice seedlings and rice plants with 32P

    International Nuclear Information System (INIS)

    Achmad Nasroh, K.

    1989-01-01

    Labelling of rice seedlings and rice plants with 32 P. Labelled rice seedlings can be used to tag insect pests that feed on. Radioactivity counting of 32 P in the endosperm and in the shoot of rice seeds that soaked for 72 hours in KH 2 32 PO 4 solution of 1 μCi/ml were 29,300 and 9,500 cpm respectively. When these labelled seedlings were grown in unlabelled medium the radioactivity in the shoot increased. It was due to the 32 P that was translocated to the shoot from the endosperm. The 32 P translocation reached maximum about one week after the seedling were grown in the unlabelled medium. Labelled seedlings could also be produced by growing 5, 10 and 15 days old seedlings hydroponically in Kimura B solution containing 32 P. Ten days after growing, the radioactivity concentration of the seedlings stem reached about 115,000; 85,000 and 170,000 cpm/mg dry weight for the 5, 10 and 15 days old seedlings respectively. For the implementation of this method, 20 ml labelled Kimura B was needed for labelling of one seedling. The seedlings should be prepared in tap water. During the growth the 32 P in the labelled seedlings was distributed throughout the plant, so that new leaves and tillers became also radioactive. (author). 5 refs

  4. Effect of Cooking on Speciation and In Vitro Bioaccessibility of Hg and As from Rice, Using Ordinary and Pressure Cookers.

    Science.gov (United States)

    Liao, Wen; Wang, Guang; Li, Kaiming; Zhao, Wenbo; Wu, Ye

    2018-05-03

    Rice is the most widely consumed staple food for a large part of the world's human population, and owing to environmental pollution, it is a major source of human exposure to mercury (Hg) and arsenic (As). We evaluated the impact of cooking on the speciation and bioaccessibility of Hg and As from rice in this study. Results show that the dominant Hg and As species in rice from Guangzhou market in China were their inorganic forms (iHg and iAs), respectively. The cooking process modified the levels of Hg and As. Average Hg and As bioaccessibility in raw rice was 69.74 and 80.32%, respectively. Hg bioaccessibility decreased to 46.22 and 42.37% for pressure- and ordinary-cooked rice, respectively. In contrast, As bioaccessibility remained unchanged except after cooking with a large amount of water. Protein denaturation and the amount of soluble and volatile forms determine the bioaccessibility of Hg and As in cooked rice by being released into the cooking water or into the air. From the bioaccessibility data, the average established daily intake (EDI) values of Hg and As from pressure-cooked rice for children and adults were 0.034 and 0.025 μg kg -1  day -1 (Hg), and 0.735 and 0.559 μg kg -1  day -1 (As), respectively. This study provides novel insights into Hg and As exposure due to rice cooking.

  5. Sustainable rice production in Malaysia beyond 2000

    International Nuclear Information System (INIS)

    Nashriyah Mat; Ho Nai Kin; Ismail Sahid; Ahyaudin Ali; Lum Keng Yeang; Mashhor Mansor

    2002-01-01

    This book is a compendium of works carried out by various institutions on subjects related to sustainable rice production. The institutions comprise Department of Agriculture, Malaysian Agricultural Research and Development Institute, Malaysian Institute for Nuclear Technology Research, Muda Agricultural Development Authority, Universiti Kebangsaan Malaysia, Universiti Putra Malaysia, Universiti Sains Malaysia, International Islamic University of Malaysia and the Agrochemical Company Mosanto. Integrated Biodiversity Management parallel with the Integrated Weed / Pest / Disease Management, rice-fish farming networking, agrochemical residue monitoring in rice and marine ecosystems, and application of biotechnology in rice productivity are taken as the future direction towards achieving sustainable rice production beyond 2000. Challenges from social and technical agroecosystem constraints, agricultural input management and maintenance of agroecosystem biodiversity are highlighted. It is imperative that the challenges are surmounted to attain the target that would be reflected by tangible rice output of 10 t/ha, and at the same time maintaining the well-being of rice-farmers. (Author)

  6. Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

    Directory of Open Access Journals (Sweden)

    Yong-liang LU

    2014-09-01

    Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and

  7. Evaluation of tall rice mutant

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1989-01-01

    One tall mutant (Mut NS1) of rice variety Nizersail was put to multilocation on-farm trial. It showed improvement over the parent in respect of by earlier maturity and higher grain yield at all locations and thus it appears as an improved mutant of Nizersail. (author). 6 refs

  8. Genome-wide transcription analyses in rice using tiling microarrays

    DEFF Research Database (Denmark)

    Li, Lei; Wang, Xiangfeng; Stolc, Viktor

    2006-01-01

    . We report here a full-genome transcription analysis of the indica rice subspecies using high-density oligonucleotide tiling microarrays. Our results provided expression data support for the existence of 35,970 (81.9%) annotated gene models and identified 5,464 unique transcribed intergenic regions...... that share similar compositional properties with the annotated exons and have significant homology to other plant proteins. Elucidating and mapping of all transcribed regions revealed an association between global transcription and cytological chromosome features, and an overall similarity of transcriptional......Sequencing and computational annotation revealed several features, including high gene numbers, unusual composition of the predicted genes and a large number of genes lacking homology to known genes, that distinguish the rice (Oryza sativa) genome from that of other fully sequenced model species...

  9. Identiifcation and validation of root-speciifc promoters in rice

    Institute of Scientific and Technical Information of China (English)

    HUANG Li-yu; ZHANG Fan; QIN Qiao; WANG Wen-sheng; ZHANG Ting; FU Bin-ying

    2015-01-01

    Novel promoters that confer root-speciifc expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-speciifc expression in rice. The isolation and characterization of upstream promoter regions of ifve selected genes rice root-speciifc promoter (rRSP) 1 to 5 (rRSP1-rRSP5) and A2P (the promoter ofOsAct2) revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-speciifc activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-speciifc enhancement of target gene(s).

  10. Mechanisms of flood tolerance in wheat and rice

    DEFF Research Database (Denmark)

    Herzog, Max

    Most crops are sensitive to excess water, and consequently floods have detrimental effects on crop yields worldwide. In addition, global climate change is expected to regionally increase the number of floods within decades, urging for more flood-tolerant crop cultivars to be released. The aim...... of this thesis was to assess mechanisms conferring rice (Oryza sativa) and wheat (Triticum aestivum) flood tolerance, focusing on the role of leaf gas films during plant submergence. Reviewing the literature showed that wheat germplasm holds genetic variation towards waterlogging (soil flooding), and highlighted...... that the contrasting submergence tolerance could rather be governed by tolerance to radical oxygen species or contrasting metabolic responses (other than carbohydrate consumption) to ethylene accumulation. Manipulating leaf gas film presence affected wheat and rice submergence tolerance such as plant growth...

  11. Draft genome sequence of an inbred line of Chenopodium quinoa, an allotetraploid crop with great environmental adaptability and outstanding nutritional properties.

    Science.gov (United States)

    Yasui, Yasuo; Hirakawa, Hideki; Oikawa, Tetsuo; Toyoshima, Masami; Matsuzaki, Chiaki; Ueno, Mariko; Mizuno, Nobuyuki; Nagatoshi, Yukari; Imamura, Tomohiro; Miyago, Manami; Tanaka, Kojiro; Mise, Kazuyuki; Tanaka, Tsutomu; Mizukoshi, Hiroharu; Mori, Masashi; Fujita, Yasunari

    2016-12-01

    Chenopodium quinoa Willd. (quinoa) originated from the Andean region of South America, and is a pseudocereal crop of the Amaranthaceae family. Quinoa is emerging as an important crop with the potential to contribute to food security worldwide and is considered to be an optimal food source for astronauts, due to its outstanding nutritional profile and ability to tolerate stressful environments. Furthermore, plant pathologists use quinoa as a representative diagnostic host to identify virus species. However, molecular analysis of quinoa is limited by its genetic heterogeneity due to outcrossing and its genome complexity derived from allotetraploidy. To overcome these obstacles, we established the inbred and standard quinoa accession Kd that enables rigorous molecular analysis, and presented the draft genome sequence of Kd, using an optimized combination of high-throughput next generation sequencing on the Illumina Hiseq 2500 and PacBio RS II sequencers. The de novo genome assembly contained 25 k scaffolds consisting of 1 Gbp with N50 length of 86 kbp. Based on these data, we constructed the free-access Quinoa Genome DataBase (QGDB). Thus, these findings provide insights into the mechanisms underlying agronomically important traits of quinoa and the effect of allotetraploidy on genome evolution. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  12. Induced Mutations in Thai Rice

    International Nuclear Information System (INIS)

    Klakhaeng, Kanchana

    2014-01-01

    Rice is the primary source of food for more than half of the world's population. It benefits greatly from technological inputs in the area of breeding such as induced mutation. Induced mutation can produce mutants with significant improvement in plant type, maturity, yields and protein ratio when compared to the parent. These improved traits enable the mutants to fit into farming systems with either shorter or longer growing seasons. Three induced mutant rice varieties, including RD6, RD10 and RD15, are well accepted by farmers and consumers in Thailand. RD6 and RD15 were aromatic, photosensitive varieties which were derived from KDML105 by acute irradiation of 20 and 15 kilorad gamma ray, respectively. After induced mutation, pedigree selection was applied. RD6 showed drought tolerance and also good grain quality including softness and good aroma with a higher average yield than the famous glutinous variety, San-Pah-Tong. Additionally, it was resistant to blast and brown spot diseases with an average yield of 4.19 tons/ha. RD15 showed drought tolerance and resistance to brown spot disease with the highest yield of 3.5 tons/ha. These two mutant varieties are currently the most famous aromatic rice varieties in Thailand. On the other hand, RD10 is a glutinous, photoperiod insensitive rice variety which was derived from RD1 by irradiation of 1 kilorad fast neutrons. RD10 showed good grain quality such as softness and stickiness with the yield of 4.25 tons/ha. As an on-going project, recommended rice varieties were irradiated with electron beam for anaerobic germination ability, submergence tolerance, stagnant-flood tolerance and also internode elongation.

  13. [Effects of fish on field resource utilization and rice growth in rice-fish coculture].

    Science.gov (United States)

    Zhang, Jian; Hu, Liang Liang; Ren, Wei Zheng; Guo, Liang; Wu, Min Fang; Tang, Jian Jun; Chen, Xin

    2017-01-01

    Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.

  14. [Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

    Science.gov (United States)

    Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

    2012-01-01

    Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).

  15. A comparative study of competitiveness between different genotypes of weedy rice (Oryza sativa) and cultivated rice.

    Science.gov (United States)

    Dai, Lei; Dai, Weimin; Song, Xiaoling; Lu, Baorong; Qiang, Sheng

    2014-01-01

    Competition from weedy rice can cause serious yield losses to cultivated rice. However, key traits that facilitate competitiveness are still not well understood. To explore the mechanisms behind the strong growth and competitive ability, replacement series experiments were established with six genotypes of weedy rice from different regions and one cultivated rice cultivar. (1) Weedy rice from southern China had the greatest impact on growth and yield of cultivated rice throughout the entire growing season. Weedy rice from the northeast was very competitive during the early vegetative stage while the competitive effects of eastern weedy rice were more detrimental at later crop-growth stages. (2) As the proportion of weedy rice increased, plant height, tillers, above-ground biomass, and yield of cultivated rice significantly declined; the crop always being at disadvantage regardless of proportion. (3) Weedy biotypes with greater diversity as estimated by their Shannon indexes were more detrimental to the growth and yield of cultivated rice. Geographic origin (latitude) of weedy rice biotype, its mixture proportion under competition with the crop and its genetic diversity are determinant factors of the outcome of competition and the associated decline in the rice crop yield. © 2013 Society of Chemical Industry. © 2013 Society of Chemical Industry.

  16. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    Directory of Open Access Journals (Sweden)

    Maria Lígia de Souza Silva

    2014-04-01

    Full Text Available Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

  17. Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability

    Science.gov (United States)

    Li, Honghong; Liu, Yuting; Chen, Yanhui; Wang, Shanli; Wang, Mingkuang; Xie, Tuanhui; Wang, Guo

    2016-08-01

    This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment.

  18. Golden rice: scientific, regulatory and public information processes of a genetically modified organism.

    Science.gov (United States)

    Moghissi, A Alan; Pei, Shiqian; Liu, Yinzuo

    2016-01-01

    Historically, agricultural development evolved in three phases. During the first phase the plants were selected on the basis of the availability of a plant with desirable properties at a specific location. The second phase provided the agricultural community with crossbreeding plants to achieve improvement in agricultural production. The evolution of biological knowledge has provided the ability to genetically engineer (GE) crops, one of the key processes within genetically modified organisms (GMO). This article uses golden rice, a species of transgenic Asian rice which contains a precursor of vitamin A in the edible part of the plant as an example of GE/GMO emphasizing Chinese experience in agricultural evolution. It includes a brief review of agricultural evolution to be followed by a description of golden rice development. Golden rice was created as a humanitarian project and has received positive comments by the scientific community and negative voices from certain environmental groups. In this article, we use the Best Available Science (BAS) Concept and Metrics for Evaluation of Scientific Claims (MESC) derived from it to evaluate claims and counter claims on scientific aspects of golden rice. This article concludes that opposition to golden rice is based on belief rather than any of its scientifically derived nutritional, safety or environmental properties.

  19. Local mat-forming cyanobacteria effectively facilitate decontamination of radioactive cesium in rice fields

    International Nuclear Information System (INIS)

    Yamamoto, Atsushi; Yoshida, Shigeru; Okumura, Hiroshi; Inagaki, Masayo; Yamanishi, Hirokuni; Ito, Tetsuo; Furukawa, Michio

    2015-01-01

    The most effective and widespread method to decontaminate radioactive cesium from the Fukushima Daiichi Nuclear Power Plant Disaster was peeling topsoil. But the method had problems, such as large amounts of discarded soil and large-scale work. In nature, cyanobacteria formed biomats on the ground surface and facilitated peeling topsoil when the biomats dried. The cyanobacteria-facilitating peeling decontamination method utilized these cyanobacterial properties. Cyanobacteria are located all over Japan and 'local' cyanobacteria could be used for decontamination without introducing new species. Utilizing cyanobacteria could decrease the amount of discarded soil to about 30% and downsize the execution-scale to individual locations. Cyanobacterial biomats were easily cultivated, especially in rice fields, by maintaining wet conditions and exposure to 100 - 83% solar radiation. Shading by a thin net was helpful in maintaining an environment suitable for cyanobacteria. Nowadays, to prevent uptake of radioactive cesium into rice, K + is usually added to fertilizer in rice fields. The K + fertilization in rice fields might also enhance cyanobacterial capture of radioactive cesium, because high concentrations of K + enhanced cyanobacterial uptake of Cs + . Cyanobacteria could also mitigate the risk of radioactive cesium moving away from a decontaminating rice field. Therefore, the cyanobacteria-facilitating peeling decontamination method was proposed as an easy and safe 'D.I.Y.' method for both farmers and the environment. Besides, plowing rice fields with water before peeling improved the efficiency of this method, because plowing increased the radioactive cesium concentration in the topsoil. (author)

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

    Science.gov (United States)

    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

  1. Aerobic rice mechanization: techniques for crop establishment

    Science.gov (United States)

    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.

  2. Assessment of Rice Associated Bacterial Ability to Enhance Rice Seed Germination and Rice Growth Promotion

    Directory of Open Access Journals (Sweden)

    R. Gholamalizadeh

    2017-08-01

    Full Text Available ABSTRACT The application of beneficial bacteria has recently been used for sustainable agriculture. In current research, 71 bacterial isolates were obtained from rice plant and the rhizosphere soil of different paddy fields in Guilan province, Iran. After primitive investigation, 40 bacteria with typical predominant characteristics were selected. By PCR-RFLP of their 16S r-DNA gene, 8 Operational Taxonomic Units (OTUs totally consisted of 33 isolates were obtained. From all of them, 8 isolates were selected for rice seed germination experiment, then, effective isolates were used for pot experiment to evaluate their ability for promoting rice growth. All of them were able to increase rice growth and yield, but in different potential. These tested isolates were identified as Alcaligenes faecalis (DEp8, O1R4, Pantoea ananatis (AEn1, Bacillus vietnamensis (MR5, Bacillus idriensis (MR2 and Stenotrophomonas maltophilia by partial sequencing of their 16S r-DNA gene. Among them, AEn1 and MR5 produced indole-3- acetic acid (IAA in larger amounts than the other isolates and the isolates AEn1 and O1R4 were able to solubilize phosphate in higher amounts. According to the results obtained, it can be concluded that AEn1, O1R4 and MR5 can be considered as bacterial inoculants to use as alternatives for chemical fertilizers.

  3. RiceFOX: a database of Arabidopsis mutant lines overexpressing rice full-length cDNA that contains a wide range of trait information to facilitate analysis of gene function.

    Science.gov (United States)

    Sakurai, Tetsuya; Kondou, Youichi; Akiyama, Kenji; Kurotani, Atsushi; Higuchi, Mieko; Ichikawa, Takanari; Kuroda, Hirofumi; Kusano, Miyako; Mori, Masaki; Saitou, Tsutomu; Sakakibara, Hitoshi; Sugano, Shoji; Suzuki, Makoto; Takahashi, Hideki; Takahashi, Shinya; Takatsuji, Hiroshi; Yokotani, Naoki; Yoshizumi, Takeshi; Saito, Kazuki; Shinozaki, Kazuo; Oda, Kenji; Hirochika, Hirohiko; Matsui, Minami

    2011-02-01

    Identification of gene function is important not only for basic research but also for applied science, especially with regard to improvements in crop production. For rapid and efficient elucidation of useful traits, we developed a system named FOX hunting (Full-length cDNA Over-eXpressor gene hunting) using full-length cDNAs (fl-cDNAs). A heterologous expression approach provides a solution for the high-throughput characterization of gene functions in agricultural plant species. Since fl-cDNAs contain all the information of functional mRNAs and proteins, we introduced rice fl-cDNAs into Arabidopsis plants for systematic gain-of-function mutation. We generated >30,000 independent Arabidopsis transgenic lines expressing rice fl-cDNAs (rice FOX Arabidopsis mutant lines). These rice FOX Arabidopsis lines were screened systematically for various criteria such as morphology, photosynthesis, UV resistance, element composition, plant hormone profile, metabolite profile/fingerprinting, bacterial resistance, and heat and salt tolerance. The information obtained from these screenings was compiled into a database named 'RiceFOX'. This database contains around 18,000 records of rice FOX Arabidopsis lines and allows users to search against all the observed results, ranging from morphological to invisible traits. The number of searchable items is approximately 100; moreover, the rice FOX Arabidopsis lines can be searched by rice and Arabidopsis gene/protein identifiers, sequence similarity to the introduced rice fl-cDNA and traits. The RiceFOX database is available at http://ricefox.psc.riken.jp/.

  4. Inorganic arsenic contents in rice-based infant foods from Spain, UK, China and USA

    International Nuclear Information System (INIS)

    Carbonell-Barrachina, Ángel A.; Wu, Xiangchun; Ramírez-Gandolfo, Amanda; Norton, Gareth J.; Burló, Francisco; Deacon, Claire; Meharg, Andrew A.

    2012-01-01

    Spanish gluten-free rice, cereals with gluten, and pureed baby foods were analysed for total (t-As) and inorganic As (i-As) using ICP-MS and HPLC–ICP-MS, respectively. Besides, pure infant rice from China, USA, UK and Spain were also analysed. The i-As contents were significantly higher in gluten-free rice than in cereals mixtures with gluten, placing infants with celiac disease at high risk. All rice-based products displayed a high i-As content, with values being above 60% of the t-As content and the remainder being dimethylarsinic acid (DMA). Approximately 77% of the pure infant rice samples showed contents below 150 μg kg −1 (Chinese limit). When daily intake of i-As by infants (4–12 months) was estimated and expressed on a bodyweight basis (μg d −1 kg −1 ), it was higher in all infants aged 8–12 months than drinking water maximum exposures predicted for adults (assuming 1 L consumption per day for a 10 μg L −1 standard). Highlights: ► Inorganic As was higher in rice-based foods than in items based on other cereals. ► Total As was very high in fish-based foods but As was present as non-toxic species. ► The maximum daily intake of i-As was found between 8 and 12 months of age. ► Pure infant rice samples from Spain presented relatively low i-As contents. ► Infants with the celiac disease are exposed to elevated levels of i-As. - Infants with the celiac disease are exposed to high levels of inorganic arsenic because of their high consumption of rice-based foods.

  5. Comparative proteomic analysis provides new insights into cadmium accumulation in rice grain under cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Dawei, E-mail: dwxue@hznu.edu.cn [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Jiang, Hua [State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Science, Hangzhou 310021 (China); Deng, Xiangxiong; Zhang, Xiaoqin [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Wang, Hua [State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Science, Hangzhou 310021 (China); Xu, Xiangbin [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); Hu, Jiang; Zeng, Dali [State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Guo, Longbiao, E-mail: guolongbiao@caas.cn [State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China); Qian, Qian, E-mail: qianqian188@hotmail.com [College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036 (China); State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006 (China)

    2014-09-15

    Graphical abstract: - Highlights: • Cd is the most toxic heavy metal and is a major pollutant in rice grains. • The mechanism of Cd accumulation in rice grains has not been well demonstrated. • Proteomics analysis is carried out and the verification is implemented by QPCR. • Proteins associated with ROS and photosynthesis showed large variation in expression. - Abstract: Rice is one of the most important staple crops. During the growth season, rice plants are inevitably subjected to numerous stresses, among which heavy metal stress represented by cadmium contamination not only hindering the yield of rice but also affecting the food safety by Cd accumulating in rice grains. The mechanism of Cd accumulation in rice grains has not been well elucidated. In this study, we compare the proteomic difference between two genotypes with different Cd accumulation ability in grains. Verification of differentially expressed protein-encoding genes was analyzing by quantitative PCR (QPCR) and reanalysis of microarray expression data. Forty-seven proteins in total were successfully identified through proteomic screening. GO and KEGG enrichment analysis showed Cd accumulation triggered stress-related pathways in the cells, and strongly affecting metabolic pathways. Many proteins associated with nutrient reservoir and starch-related enzyme were identified in this study suggesting that a considerably damage on grain quality was caused. The results also implied stress response was initiated by the abnormal cells and the transmission of signals may mediated by reactive oxygen species (ROS). Our research will provide new insights into Cd accumulation in rice grain under Cd stress.

  6. Comparative Proteomic Analysis of Susceptible and Resistant Rice Plants during Early Infestation by Small Brown Planthopper

    Directory of Open Access Journals (Sweden)

    Yan Dong

    2017-10-01

    Full Text Available The small brown planthopper (Laodelphax striatellus Fallén, Homoptera, Delphacidae-SBPH is one of the major destructive pests of rice (Oryza sativa L.. Understanding on how rice responds to SBPH infestation will contribute to developing strategies for SBPH control. However, the response of rice plant to SBPH is poorly understood. In this study, two contrasting rice genotypes, Pf9279-4 (SBPH-resistant and 02428 (SBPH-susceptible, were used for comparative analysis of protein profiles in the leaf sheath of rice plants in responses to SBPH infestation. One hundred and thirty-two protein spots that were differentially expressed between the resistant and susceptible rice lines were identified with significant intensity differences (≥2-fold, P < 0.05 at 0, 6, and 12 h after SBPH infestation. Protein expression profile analysis in the leaf sheath of SBPH-resistant and SBPH-susceptible rice lines after SBPH infestation showed that proteins induced by SBPH feeding were involved mainly in stress response, photosynthesis, protein metabolic process, carbohydrate metabolic process, energy metabolism, cell wall-related proteins, amino acid metabolism and transcriptional regulation. Gene expression analysis of 24 differentially expressed proteins (DEPs showed that more than 50% DEPs were positively correlated with their mRNA levels. Analysis of some physiological indexes mainly involved in the removal of oxygen reactive species showed that the levels of superoxide dismutase (SOD and glutathione (GSH were considerably higher in Pf9279-4 than 02428 during SBPH infestation. The catalase (CAT activity and hydroxyl radical inhibition were lower in Pf9279-4 than 02428. Analysis of enzyme activities indicates that Pf9279-4 rice plants defend against SBPH through the activation of the pathway of the salicylic acid (SA-dependent systemic acquired resistance. In conclusion, this study provides some insights into the molecular networks involved on cellular and

  7. Tier I Rice Model - Version 1.0 - Guidance for Estimating Pesticide Concentrations in Rice Paddies

    Science.gov (United States)

    Describes a Tier I Rice Model (Version 1.0) for estimating surface water exposure from the use of pesticides in rice paddies. The concentration calculated can be used for aquatic ecological risk and drinking water exposure assessments.

  8. Levels and patterns of nucleotide variation in domestication QTL regions on rice chromosome 3 suggest lineage-specific selection.

    Directory of Open Access Journals (Sweden)

    Xianfa Xie

    Full Text Available Oryza sativa or Asian cultivated rice is one of the major cereal grass species domesticated for human food use during the Neolithic. Domestication of this species from the wild grass Oryza rufipogon was accompanied by changes in several traits, including seed shattering, percent seed set, tillering, grain weight, and flowering time. Quantitative trait locus (QTL mapping has identified three genomic regions in chromosome 3 that appear to be associated with these traits. We would like to study whether these regions show signatures of selection and whether the same genetic basis underlies the domestication of different rice varieties. Fragments of 88 genes spanning these three genomic regions were sequenced from multiple accessions of two major varietal groups in O. sativa--indica and tropical japonica--as well as the ancestral wild rice species O. rufipogon. In tropical japonica, the levels of nucleotide variation in these three QTL regions are significantly lower compared to genome-wide levels, and coalescent simulations based on a complex demographic model of rice domestication indicate that these patterns are consistent with selection. In contrast, there is no significant reduction in nucleotide diversity in the homologous regions in indica rice. These results suggest that there are differences in the genetic and selective basis for domestication between these two Asian rice varietal groups.

  9. Herbicidal activity of pre and post emergent herbicide on control of Eleusine indica in aerobic rice system

    International Nuclear Information System (INIS)

    Selvarajh, G.; Zain, N.M.; Aminudin, A.; Seng, C.T.

    2018-01-01

    Aerobic rice system can be an alternate way to cultivate rice in less water conditions. However, weeds are a major constrain in aerobic rice field which decline its success. Weeds are being controlled by herbicides in aerobic rice but not all herbicides are effective in controlling various types of weeds. In this study, two pre-emergent (pretilachor and pendimethalin) and two post-emergent (cyhalofop-butyl and bispyribac-sodium) herbicides were evaluated for effective control of the bioassay species, Eleusine indica. It was found that pendimethalin at a higher application rate of 1.0 kg ai ha-1 strongly inhibit the emergence and shoot growth of E. indica by >75% with negligible effect on the rice growth with stimulation on the leaf greenness. Conversely, pretilachor, cyhalofop-butyl and bispyribac-sodium gave moderate inhibition (55-60% inhibition) on weed emergence and shoot growth at higher application rates of 0.44, 0.1 and 0.035 kg ai ha-1, respectively. Significant inhibitory effects on rice root growth were noticed at highest application rates of pretilachor, cyhalofop-butyl and bispyribac-sodium (40-50% inhibition) across the growth stage of rice seedlings. Great reduction in shoot height, shoot fresh weight, and greenness of rice plant also was evident at 0 DAS across herbicides rates. However, with increasing growth stages, the rice plant became less susceptible to the applied treatments. The finding suggested that pendimethalin at 1.0 kg ai ha-1 was the most suitable application rate for inhibiting E. indica without injuring the rice seedlings. (author)

  10. significance of rice sheath photosynthesis: yield determination by c ...

    African Journals Online (AJOL)

    ACSS

    1State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, P.R. China. 2School of ... for contribution rates of sheath photosynthesis to economical yield. ..... related processes during ripening in rice plants.

  11. Perceived factors limiting rice production in Pategi Local ...

    African Journals Online (AJOL)

    user

    perceived limiting factors in rice production include lack of rice processing ... This production increase has not been enough to meet the consumption demand of ... of Kwara State, Nigeria seeks to determine some of the factors limiting rice ...

  12. potential for biological control of rice yellow mottle virus vectors

    African Journals Online (AJOL)

    Administrator

    Insect pests and disease infestations are the primary constraints in rice (Oryza sativa) production .... Asia. Of all the rice diseases, the one caused by the rice yellow mottle virus (RYMV), first reported ..... yellow mottle virus in Central Africa.

  13. Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

    Directory of Open Access Journals (Sweden)

    Shi-ping LIU

    2007-09-01

    Full Text Available The interplanting with zero-tillage of rice, i.e. direct sowing rice 10–20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting, ZI (Zero-tillage, no straw manure and rice interplanting, PTS (Plowing tillage, straw manure and rice transplanting, and PT (Plowing tillage, no straw manure and rice transplanting, were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003. Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments

  14. A comprehensive crop genome research project: the Superhybrid Rice Genome Project in China.

    Science.gov (United States)

    Yu, Jun; Wong, Gane Ka-Shu; Liu, Siqi; Wang, Jian; Yang, Huanming

    2007-06-29

    In May 2000, the Beijing Institute of Genomics formally announced the launch of a comprehensive crop genome research project on rice genomics, the Chinese Superhybrid Rice Genome Project. SRGP is not simply a sequencing project targeted to a single rice (Oryza sativa L.) genome, but a full-swing research effort with an ultimate goal of providing inclusive basic genomic information and molecular tools not only to understand biology of the rice, both as an important crop species and a model organism of cereals, but also to focus on a popular superhybrid rice landrace, LYP9. We have completed the first phase of SRGP and provide the rice research community with a finished genome sequence of an indica variety, 93-11 (the paternal cultivar of LYP9), together with ample data on subspecific (between subspecies) polymorphisms, transcriptomes and proteomes, useful for within-species comparative studies. In the second phase, we have acquired the genome sequence of the maternal cultivar, PA64S, together with the detailed catalogues of genes uniquely expressed in the parental cultivars and the hybrid as well as allele-specific markers that distinguish parental alleles. Although SRGP in China is not an open-ended research programme, it has been designed to pave a way for future plant genomics research and application, such as to interrogate fundamentals of plant biology, including genome duplication, polyploidy and hybrid vigour, as well as to provide genetic tools for crop breeding and to carry along a social burden-leading a fight against the world's hunger. It began with genomics, the newly developed and industry-scale research field, and from the world's most populous country. In this review, we summarize our scientific goals and noteworthy discoveries that exploit new territories of systematic investigations on basic and applied biology of rice and other major cereal crops.

  15. Characterization of Mediator Complex and its Associated Proteins from Rice.

    Science.gov (United States)

    Samanta, Subhasis; Thakur, Jitendra Kumar

    2017-01-01

    The Mediator complex is a multi-protein complex that acts as a molecular bridge conveying transcriptional messages from the cis element-bound transcription factor to the RNA Polymerase II machinery. It is found in all eukaryotes including members of the plant kingdom. Increasing number of reports from plants regarding different Mediator subunits involved in a multitude of processes spanning from plant development to environmental interactions have firmly established it as a central hub of plant regulatory networks. Routine isolation of Mediator complex in a particular species is a necessity because of many reasons. First, composition of the Mediator complex varies from species to species. Second, the composition of the Mediator complex in a particular species is not static under all developmental and environmental conditions. Besides this, at times, Mediator complex is used in in vitro transcription systems. Rice, a staple food crop of the world, is used as a model monocot crop. Realizing the need of a reliable protocol for the isolation of Mediator complex from plants, we describe here the isolation of Mediator complex from rice.

  16. Assessing the impacts of climate change on rice yields in the main rice areas of China

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Fengmei [College of Earth Sciences, The Graduate University of the Chinese Academy of Sciences, 19A, Yuquan Road, Beijing, 100049 (China); Xu, Yinglong; Lin, Erda [Agricultural Environment and Sustainable Development Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 (China); Yokozawa, Masayuki [National Institute for Agro-environmental Sciences, Tsukuba 305-8604 (Japan); Zhang, Jiahua [Chinese Academy of Meteorological Sciences, Beijing, 100081 (China)

    2007-02-15

    This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within {+-} 10% of observed flowering duration and {+-} 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations.

  17. Assessing the impacts of climate change on rice yields in the main rice areas of China

    International Nuclear Information System (INIS)

    Yao, Fengmei; Xu, Yinglong; Lin, Erda; Yokozawa, Masayuki; Zhang, Jiahua

    2007-01-01

    This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within ± 10% of observed flowering duration and ± 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations

  18. Rice Seedling Substrate Produced by Coal Gangue

    Directory of Open Access Journals (Sweden)

    SHAO Yu-fei

    2017-10-01

    Full Text Available Peats are the mostly used material in making rice seedling substrate. However, mining peats could cause environmental problems. In order to reduce or replace peats in rice seedling substrate industry, this paper studied suitable way to configure rice seedling. The coal gangue was used to experiment cultivating rice. Four rice seeding experiments were carried out based on physical and chemical properties of materials attributes. The results showed:(1 Coal gangue was feasible for rice seedling; (2 The maximum adding amount of coal gangue was 80%(volume ratio though the coal gangue need to be activated; (3 In the case of no activated treatment only 38%(volume ratio of coal gangue could be added to the substrate.

  19. Improvement of rice starch by gamma irradiation

    International Nuclear Information System (INIS)

    Duan Zhiying; Wu Dianxing; Shen Shengquan; Han Juanying; Xia Yingwu

    2003-01-01

    Three types of rice cultivars, Indica, Japonica and hybrid rice, with similar intermediate apparent amylose content (AAC) as well as early Indica rice cultivars with different amounts of AAC were selected for studying the effects of gamma irradiation on starch viscosity, physico-chemical properties and starch granule structure. Four major parameters of RVA profile, peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV) and consistence viscosity (CSV) were considerably decreased with increasing dose levels. Gamma irradiation reduced the amylose contents in the cultivars with low AAC, intermediate AAC, and glutinous rice, but had no effects on the high AAC cultivar. No visible changes in alkali spreading value (ASV) were detected after irradiation, but the peak time (PKT) were reduced with the dose level. Gel consistency (GC) were significantly increased in the tested cultivars, especially in the high AAC Indica rice, suggesting that it is promising to use gamma irradiation to improve eating and cooking quality of rice

  20. Rice terpene synthase 24 (OsTPS24) encodes a jasmonate-responsive monoterpene synthase that produces an antibacterial γ-terpinene against rice pathogen.

    Science.gov (United States)

    Yoshitomi, Kayo; Taniguchi, Shiduku; Tanaka, Keiichiro; Uji, Yuya; Akimitsu, Kazuya; Gomi, Kenji

    2016-02-01

    Rice is one of the most important crops worldwide and is widely used as a model plant for molecular studies of monocotyledonous species. The plant hormone jasmonic acid (JA) is involved in rice-pathogen interactions. In addition, volatile compounds, including terpenes, whose production is induced by JA, are known to be involved in the rice defense system. In this study, we analyzed the JA-induced terpene synthase OsTPS24 in rice. We found that OsTPS24 was localized in chloroplasts and produced a monoterpene, γ-terpinene. The amount of γ-terpinene increased after JA treatment. γ-Terpinene had significant antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo); however, it did not show significant antifungal activity against Magnaporthe oryzae. The antibacterial activity of the γ-terpinene against Xoo was caused by damage to bacterial cell membranes. These results suggest that γ-terpinene plays an important role in JA-induced resistance against Xoo, and that it functions as an antibacterial compound in rice. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. RiceAtlas, a spatial database of global rice calendars and production

    NARCIS (Netherlands)

    Laborte, Alice G.; Gutierrez, Mary Anne; Balanza, Jane Girly; Saito, Kazuki; Zwart, Sander; Boschetti, Mirco; Murty, M. V.R.; Villano, Lorena; Aunario, Jorrel Khalil; Reinke, Russell; Koo, Jawoo; Hijmans, Robert J.; Nelson, Andrew

    2017-01-01

    Knowing where, when, and how much rice is planted and harvested is crucial information for understanding the effects of policy, trade, and global and technological change on food security. We developed RiceAtlas, a spatial database on the seasonal distribution of the world's rice production. It

  2. DETERMINATION OF SPATIAL INTEGRATION AND SUBSTITUTION OF FOREIGN RICE FOR LOCAL RICE IN GHANA

    Directory of Open Access Journals (Sweden)

    Philip Kofi ADOM

    2014-11-01

    Full Text Available This study tested for spatial integration in the rice market and the substitution of imported rice for local rice in Ghana. It is established that the markets for domestic imported rice are well-integrated, but not complete. The imperfect spatial integration of domestic foreign rice markets implies that the market provides opportunities for arbitrage. Price leadership roles are found to be determined by the kind of sub-inter-regional-trade network defined. However, in all, the Accra market emerged as a dominant market leader in the domestic foreign rice market. There is evidence of significant regional substitution of foreign rice for local rice in the long run, but the result is mixed in the short run. The result that local rice is not a perfect substitute for imported rice implies that price disincentive measures such as increasing the import tariffs on foreign rice will only produce a mild effect on increasing the producer price faced by local rice farmers, but aggravate the burden on households’ budget.

  3. Soil to rice transfer factors for 210Pb: a study on rice grown in India

    International Nuclear Information System (INIS)

    Karunakara, N.; Rao, Chetan; Ujwal, P.; Yashodhara, I.; Sudeep Kumara; Somashekarappa, H.M.; Bhaskara Shenoy, K.; Ravi, P.M.

    2013-01-01

    India is the second largest producer of rice (Oryza sativa L.) in the world and rice is the essential component of the diet for the majority of the population of India. However, detailed studies aimed at evaluation of radionuclide transfer factors (F v ) for rice grown in India are almost non-existent. This paper presents soil to rice transfer factors for 210 Pb for rice grown in natural field conditions on the West Coast of India. A rice field was developed very close to the Kaiga nuclear power plant for the field studies. For a comparative study of radionuclide transfer factors, rice samples were also collected from the rice fields of nearby villages. The soil to un-hulled rice grain 210 Pb varied in the range <1.2 x10 -2 to 8.1 x 10 -1 with a mean of 1.4 x 10 -1 . The mean values of un-hulled grain to white rice processing retention factors (F r ) was 0.03 for 210 Pb. Using the processing retention factors the soil to white rice transfer factor was estimated and found to have the mean value of 4.2 x 10 -3 . The study has shown that the transfer of 210 Pb was retained in the root and its transfer to above ground organs of rice plant is significantly lower. (author)

  4. An Economic Risk Analysis of Weed Suppressive Rice Cultivars in Rice Production

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the United States, most rice cultivars are not inherently weed-suppressive and require substantial herbicide inputs to achieve agronomic and economic viability. Intensive herbicide application in rice also has many potential drawbacks, resulting in...

  5. Salinity alters the protein composition of rice endosperm and the physicochemical properties of rice flour.

    Science.gov (United States)

    Baxter, Graeme; Zhao, Jian; Blanchard, Christopher

    2011-09-01

    Salinity is one of the major threats to production of rice and other agricultural crops worldwide. Although numerous studies have shown that salinity can severely reduce rice yield, little is known about its impact on the chemical composition, processing and sensory characteristics of rice. The objective of the current study was to investigate the effect of salinity on the pasting and textural properties of rice flour as well as on the protein content and composition of rice endosperm. Rice grown under saline conditions had significantly lower yields but substantially higher protein content. The increase in protein content was mainly attributed to increases in the amount of glutelin, with lesser contributions from albumin. Salinity also altered the relative proportions of the individual peptides within the glutelin fraction. Flours obtained from rice grown under saline conditions showed significantly higher pasting temperatures, but lower peak and breakdown viscosities. Rice gels prepared from the flour showed significantly higher hardness and adhesiveness values, compared to the freshwater controls. Salinity can significantly affect the pasting and textural characteristics of rice flour. Although some of the effects could be attributed to changes in protein content of the rice flour, especially the increased glutelin level, the impact of salinity on the physicochemical properties of rice is rather complex and may involve the interrelated effects of other rice components such as starch and lipids. Copyright © 2011 Society of Chemical Industry.

  6. Medicinal and nutritional importance of rice bran

    International Nuclear Information System (INIS)

    Ahmad, R.; Salim, M.; Rauf, R.; Baloach, M.K.

    2005-01-01

    Rice-bran is produced from the outer layer of brown rice and is stabilized through steam-heating. The rice-bran and its products are safe for human and animal consumption. The microbiological safety and rigorous quality-control practices merits its use as nutritional and dietary supplement for overall health-maintenance and as a part of a healthy diet and life-style, as it contributes to the reduction of certain diseases and health-related conditions. Stabilized rice-barn contain 15% of high nutritional- value protein, 20% of high-quality fat with Omega-3 and Omega-6 fatty acids, and nutritional dietary fiber. In addition to several phytonutrients, rice-bran contains vitamins and minerals, while over 100 potent antioxidants have been identified to date. Several scientific papers have reported the analysis and bioavailibility of rice-bran nutrients. Various chemical studies demonstrated the biological effects of the nutrients found in rice-bran. So far, more than 250 scientific publications are available on rice-bran, establishing the striking medicinal properties of rice-bran products. The oil-fraction of rice-bran has concentrated all tire fat-soluble phytonutrient in it, making itself an excellent health-promoting edible oil, as well as message oil The fiber-fraction of rice-bran has a profound effect on the gastrointestinal health, and improves bowel function. Rice-bran fiber along with phytonutrients was found to reduce cholesterol and lipid levels and maintain cardiovascular function. It has beneficial effect on tire kidney and urinary tract health and is helpful in weight-management and fiber replacement diets. (author)

  7. Chloroplast genes as genetic markers for inferring patterns of change, maternal ancestry and phylogenetic relationships among Eleusine species.

    Science.gov (United States)

    Agrawal, Renuka; Agrawal, Nitin; Tandon, Rajesh; Raina, Soom Nath

    2014-01-01

    Assessment of phylogenetic relationships is an important component of any successful crop improvement programme, as wild relatives of the crop species often carry agronomically beneficial traits. Since its domestication in East Africa, Eleusine coracana (2n = 4x = 36), a species belonging to the genus Eleusine (x = 8, 9, 10), has held a prominent place in the semi-arid regions of India, Nepal and Africa. The patterns of variation between the cultivated and wild species reported so far and the interpretations based upon them have been considered primarily in terms of nuclear events. We analysed, for the first time, the phylogenetic relationship between finger millet (E. coracana) and its wild relatives by species-specific chloroplast deoxyribonucleic acid (cpDNA) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and chloroplast simple sequence repeat (cpSSR) markers/sequences. Restriction fragment length polymorphism of the seven amplified chloroplast genes/intergenic spacers (trnK, psbD, psaA, trnH-trnK, trnL-trnF, 16S and trnS-psbC), nucleotide sequencing of the chloroplast trnK gene and chloroplast microsatellite polymorphism were analysed in all nine known species of Eleusine. The RFLP of all seven amplified chloroplast genes/intergenic spacers and trnK gene sequences in the diploid (2n = 16, 18, 20) and allotetraploid (2n = 36, 38) species resulted in well-resolved phylogenetic trees with high bootstrap values. Eleusine coracana, E. africana, E. tristachya, E. indica and E. kigeziensis did not show even a single change in restriction site. Eleusine intermedia and E. floccifolia were also shown to have identical cpDNA fragment patterns. The cpDNA diversity in Eleusine multiflora was found to be more extensive than that of the other eight species. The trnK gene sequence data complemented the results obtained by PCR-RFLP. The maternal lineage of all three allotetraploid species (AABB, AADD) was the same, with E. indica being the

  8. No direct effects of two transgenic Bt rice lines, T1C-19 and T2A-1, on the arthropod communities.

    Science.gov (United States)

    Lu, Z B; Tian, J C; Han, N S; Hu, C; Peng, Y F; Stanley, David; Ye, G Y

    2014-10-01

    A 2-yr field trial was conducted to assess the impacts of two new transgenic Bt rice lines, T1C-19 expressing Cry1C protein and T2A-1 expressing Cry2A protein, on the arthropod community sampled via vacuum. All the arthropods were classified into five guilds, including herbivores, parasitoids, predators, detritivores, and others. The seasonal density and dominance distribution of each guild and community-level indices (species richness, Shannon-Wiener diversity index, Simpson diversity index, and evenness index) were compared among rice types. Principal response curves were used to investigate the differences of entire arthropod community of Bt rice plots relative to non-Bt rice plots. The results showed no significant difference was detected in the community-level indices and dominance distribution of guilds between Bt and non-Bt rice plots. The seasonal density of herbivores, detritivores, and others as well as density of the arthropod overall community were also not significantly affected by rice types in either year, although the density of predators and parasitoids in Bt rice plots was significantly lower than those in non-Bt rice plots. The lower abundances of Braconidae, Eulophidae, Cyrtorhinus lividipennis (Reuter) (Hemiptera: Miridae), and Theridiidae in Bt rice plots are likely attributed to the lower abundances of prey species or hosts. Principal response curves revealed that arthropod community in Bt was similar with that in non-Bt rice plots. In conclusion, our findings indicate that these two tested Bt rice lines had no marked negative effects on the arthropod community in the paddy fields.

  9. Could abiotic stress tolerance in wild relatives of rice be used to improve Oryza sativa?

    Science.gov (United States)

    Atwell, Brian J; Wang, Han; Scafaro, Andrew P

    2014-02-01

    Oryza sativa and Oryza glaberrima have been selected to acquire and partition resources efficiently as part of the process of domestication. However, genetic diversity in cultivated rice is limited compared to wild Oryza species, in spite of 120,000 genotypes being held in gene banks. By contrast, there is untapped diversity in the more than 20 wild species of Oryza, some having been collected from just a few coastal locations (e.g. Oryza schlechteri), while others are widely distributed (e.g. Oryza nivara and Oryza rufipogon). The extent of DNA sequence diversity and phenotypic variation is still being established in wild Oryza, with genetic barriers suggesting a vast range of morphologies and function even within species, such as has been demonstrated for Oryza meridionalis. With increasing climate variability and attempts to make more marginal land arable, abiotic and biotic stresses will be managed over the coming decades by tapping into the genetic diversity of wild relatives of O. sativa. To help create a more targeted approach to sourcing wild rice germplasm for abiotic stress tolerance, we have created a climate distribution map by plotting the natural occurrence of all Oryza species against corresponding temperature and moisture data. We then discuss interspecific variation in phenotype and its significance for rice, followed by a discussion of ways to integrate germplasm from wild relatives into domesticated rice. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Effect of a combination of two rice herbicides on the cyanobacterium, Nostoc spongiaeforme

    Science.gov (United States)

    Cyanobacteria grow in California rice fields where they form large mats that may smoother seedlings or cause them to dislodge, resulting in yield loss. The most troublesome species is Nostoc spongiaeforme. It is very difficult to control using currently accepted methods, i.e., aerial applications of...

  11. Parasitic weed incidence and related economic losses in rice in Africa

    NARCIS (Netherlands)

    Rodenburg, Jonne; Demont, Matty; Zwart, Sander J.; Bastiaans, Lammert

    2016-01-01

    Parasitic weeds pose increasing threats to rain-fed rice production in Africa. Most important species are Striga asiatica, S. aspera and S. hermonthica in rain-fed uplands, and Rhamphicarpa fistulosa in rain-fed lowlands. Information on the regional spread and economic importance of parasitic weeds

  12. Identity and relative importance of egg predators of rice leaffolders (Lepidoptera:Pyralidae.)

    NARCIS (Netherlands)

    Kraker, de J.; Huis, van A.; Lenteren, van J.C.; Heong, K.L.; Rabbinge, R.

    2000-01-01

    Field andlaboratory studies on predation of rice leaffolder eggs (i.e., Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley) were conducted to identify major predator species. Direct observations of predation on field-exposed eggs showed that in two seasons Metioche vittaticollis (Stål)

  13. Rice breeding with induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    1968-06-01

    The Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture decided in 1964 to organize a co-ordinated research programme on the use of induced mutations in rice breeding. The programme was organized within the framework of activities of the International Rice Commission. This is a report of the Third Co-ordination Meeting of the participants, which was held in Taipei, 5-9 June 1967. As the projects, which together make up the co-ordinated programme, are at different stages of progress, the report contains a variety of papers including completed studies, field and progress reports, and highlights of the discussions with some additional recommendations prepared by the participants. Refs, figs and tabs.

  14. Bioethanol production from rice straw residues

    Directory of Open Access Journals (Sweden)

    Elsayed B. Belal

    2013-01-01

    Full Text Available A rice straw -cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 ºC, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L-1.

  15. Response Of Lowland Rice To Soil Compaction

    International Nuclear Information System (INIS)

    Idawati; Haryanto

    2000-01-01

    Soil compaction, as a new tillage practice for paddy soil, is to substitute pudding in order to reduce land preparation cost. To study response of lowland rice to soil compaction, a pot experiment has been conducted which took place in the greenhouse of P3TIR-BATAN. Soil for experiment was taken from pusakanegara. Two factors (degree of soil compaction and rice variety) were combined. Degree of compaction was split into 3 levels (DI = normal; D215% more compact than normal; 30 % more compact than normal), and rice variety into 2 levels (IR64 and Atomita IV). KH 2 32 PO 4 solution was injected into the soil surrounding rice clump to test the root activity at blooming stage of rice plant. Data resulted from this experiment is presented together with additional data from some other experiments of fertilization in the research s erie to study soil compaction. Some information's from experiment results are as following. Both rice varieties tested gave the same response to soil compaction. Root activity, according to data of 32 P absorbed by plant, was not harmed by soil compaction at the degree tested in the experiment. This prediction is supported by the growth by rice observed at generative growth stage, in pot experiment as well as in field experiment, which showed that soil compaction tested did not decrease rice yield but in opposite in tended to increase the yield. In practising soil compaction in land preparation, fertilizers should be applied by deep placement to have higher increasing is rice yield

  16. Enzymatic hydrolsis of pretreated rice straw

    Energy Technology Data Exchange (ETDEWEB)

    Vlasenko, E.Y.; Shoemaker, S.P. [California Inst. of Food and Agricultural Research, Davis, CA (United States); Ding, H. [California Univ., Davis (Canada). Dept. of Food Science and Technology; Labavitch, J.M. [California Univ., Davis, CA (United States). Dept. of Pomology

    1997-02-01

    California rice straw is being evaluated as a feedstock for production of power and fuel. This paper examines the initial steps in the process: pretreatment of rice straw and enzymatic hydrolysis of the polysaccharides in the pretreated material to soluble sugars. Rice straw was subjected to three distinct pretreatment procedures: acid-catalyzed steam explosion (Swan Biomass Company), acid hydrolysis (U.S. DOE National Renewable Energy Laboratory), and ammonia fiber explosion or AFEX (Texas A and M University). Standard conditions for each pretreatment were used, but none was optimized for rice straw specifically. Six commercial cellulases, products of Genencor International (USA), Novo (Denmark), Iogen (Canada) and Fermtech (Russia) were used for hydrolysis. The Swan- and the acid-pretreatments effectively removed hemicellulose from rice straw, providing high yields of fermentable sugars. The AFEX-pretreatment was distinctly different from other pretreatments in that it did not significantly solubilize hemicellulose. All three pretreatment procedures substantially increased enzymatic digestibility of rice straw. Three commercial Trichoderma-reesei-derived enzyme preparations: Cellulase 100L (Iogen), Spezyme CP (Genencor), and Al (Fermtech), were more active on pretreated rice straw compared than others tested. Conditions for hydrolysis of rice straw using Cellulase 100L were evaluated. The supplementation of this enzyme preparation with cellobiase (Novozyme 188) significantly improved the parameters of hydrolysis for the Swan- and the acid-pretreated materials, but did not affect the hydrolysis of the AFEX-pretreated rice straw. (Author)

  17. Compressive Load Resistance Characteristics of Rice Grain

    OpenAIRE

    Sumpun Chaitep; Chaiy R. Metha Pathawee; Pipatpong Watanawanyoo

    2008-01-01

    Investigation was made to observe the compressive load property of rice gain both rough rice and brown grain. Six rice varieties (indica and japonica) were examined with the moisture content at 10-12%. A compressive load with reference to a principal axis normal to the thickness of the grain were conducted at selected inclined angles of 0°, 15°, 30°, 45°, 60° and 70°. The result showed the compressive load resistance of rice grain based on its characteristic of yield s...

  18. Phloem Transport Of Arsenic Species From Flag Leaf To Grain During Grain Filling

    Science.gov (United States)

    Strategies to reduce arsenic (As) in rice grain, below concentrations that represent a serious human health concern, require that the mechanisms of As accumulation within grain be established. Therefore, retranslocation of As species from flag leaves into filling rice grain was ...

  19. Elemental composition of Malawian rice.

    OpenAIRE

    Joy, EJM; Louise Ander, E; Broadley, MR; Young, SD; Chilimba, AD; Hamilton, EM; Watts, MJ

    2016-01-01

    Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic...

  20. Gamma irradiation of rice grains

    International Nuclear Information System (INIS)

    Roy, M.K.; Ghosh, S.K.; Chatterjee, S.R.

    1991-01-01

    Rice grains of the variety, Pusa-33, at 12.0% moisture, were irradiated with doses of 0-150 kGy. The crystallinity of starch, soluble amylose and yellowness of treated grains increased with increment in the dose of radiation but water absorption and volume expansion on cooling decreased. irradiation at doses of 3-5 kGy increased imperceptibly the hardening of rice cooled after cooking, but had no effect on edibility. The off-aroma in irradiated grains was perceptible at doses higher than 5 kGy. The changes in colour and aroma persisted also on cooking. Upto a dose of 5 kGy, the sensory scores of rice, both cooked and uncooked, were at or above acceptable limit of score (5,5). The doses of 3 and 5 kGy were highly effective in reducing fungal population in irradiated grains, but in view of the changes in colour and cooking qualities, 3 kGy is the preferred dose-limit of irradiation. (author). 17 refs., 5 tabs., 1 fig

  1. Proteomics of Rice Seed Germination

    Directory of Open Access Journals (Sweden)

    Dongli eHe

    2013-07-01

    Full Text Available Seed is a condensed form of plant. Under suitable environmental conditions, it can resume the metabolic activity from physiological quiescent status, and mobilize the reserves, biosynthesize new proteins, regenerate organelles and cell membrane, eventually protrude the radicle and enter into seedling establishment. So far, how these activities are regulated in a coordinated and sequential manner is largely unknown. With the availability of more and more genome sequence information and the development of mass spectrometry (MS technology, proteomics has been widely applied in analyzing the mechanisms of different biological processes, and proved to be very powerful. Regulation of rice seed germination is critical for rice cultivation. In recent years, a lot of proteomic studies have been conducted in exploring the gene expression regulation, reserves mobilization and metabolisms reactivation, which brings us new insights on the mechanisms of metabolism regulation during this process. Nevertheless, it also invokes a lot of questions. In this mini-review, we summarized the progress in the proteomic studies of rice seed germination. The current challenges and future perspectives were also discussed, which might be helpful for the following studies.

  2. Clustering of 18 Local Black Rice Base on Total Anthocyanin

    Directory of Open Access Journals (Sweden)

    Kristamtini Kristamtini

    2017-10-01

    Full Text Available Black rice has a high anthocyanin content in the pericarp layer, which provides a dark purple color. Anthocyanin serve as an antioxidant that control cholesterol level in the blood, prevent anemia, potentially improve the body's resistance to disease, improve damage to liver cells (hepatitis and chirrosis, prevent impaired kidney function, prevent cancer/tumors, slows down antiaging, and prevent atherosclerosis and cardiovascular disease. Exploration results at AIAT Yogyakarta, Indonesia from 2011 to 2014 obtained 18 cultivar of local black rice Indonesia. The names of the rice are related to the color (black, red or purple formed by anthocyanin deposits in the pericarp layer, seed coat or aleuron. The objective of the study was to classify several types of local black rice from explorations based on the total anthocyanin content. The study was conducted by clustering analyzing the total anthocyanin content of 18 local black rice cultivars in Indonesia. Cluster analysis of total anthocyanin content were done using SAS ver. 9.2. Clustering dendogram shows that there were 4 groups of black rice cultivars based on the total anthocyanin content. Group I consists of Melik black rice, Patalan black rice, Yunianto black rice, Muharjo black rice, Ngatijo black rice, short life of Tugiyo black rice, Andel hitam 1, Jlitheng, and Sragen black rice. Group II consists of Pari ireng, Magelang black hairy rice, Banjarnegara-Wonosobo black rice, and Banjarnegara black rice. Group III consists of NTT black rice, Magelang non hairy black rice, Sembada hitam, and longevity Tugiyo black rice. Group IV consist only one type of black rice namely Cempo ireng. The grouping result indicate the existence of duplicate names among the black rice namely Patalan with Yunianto black rice, and short life Tugiyo with Andel hitam 1 black rice.

  3. Co-occurrence of citrinin and ochratoxin A in rice in Asia and its implications for human health.

    Science.gov (United States)

    Ali, Nurshad

    2018-04-01

    Citrinin (CIT) and ochratoxin A (OTA) are nephrotoxic mycotoxins, produced by several Aspergillus and Penicillium species and their co-occurrence in rice may cause health effects in humans. Rice is an important food crop worldwide and is a major staple food in Asia which may be invaded by CIT and OTA producing fungal spores in the field, during harvest and storage. Humans are exposed to these mycotoxins through ingestion of contaminated rice and other food commodities. Yet, data on the combined presence to these food contaminants are still insufficient to estimate human exposure in Asia. This review describes the prevalence of CIT and OTA in rice in Asia and its implications on human health, which may help in establishing and carrying out proper management strategies against mould development on rice. From the health point of view, combined exposition of CIT and OTA should be a public concern as both are nephrotoxic and long-term exposure can pose detrimental health effects. Thus, it is necessary for local farmers and food factories to implement strict measures and to improve methods for rice preservation during the distribution to consumers, particularly in the markets. Moreover, regular surveys for CIT and OTA occurrence in rice and human biomonitoring are recommended to reduce the health effects in Asian population. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios

    OpenAIRE

    Streck,Nereu A.; Uhlmann,Lilian O.; Gabriel,Luana F.

    2013-01-01

    The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence dat...

  5. Potential of mutation breeding in improving Indonesian local rice varieties

    International Nuclear Information System (INIS)

    Sobrizal

    2016-01-01

    Rice (Oryza sativa L.) is an important cereal crops for human nutrition, this species can be divided into sub-species i.e. Indica and Japonica. Japonica sub-species consists of Temprate and Tropical Japonica (it is called as Javanica) groups. Mostly Javanica group originated from Indonesia, the people mentioned as Indonesian local varieties, it was covering more than 8000 varieties. This paper aims is to discuss the potential of mutation breeding, success stories and on going activities improved genetically the local rice varieties. Indonesian local varieties have been tested naturally for resistance to biotic and abiotic stresses so that they become useful collections of genetic resources. They usually adapted well toa specific environment where they grow largely, having good aroma and eating quality, but they have some weakness such very long growth duration, susceptible to lodging, unresponsive to fertilizer, and low yield. Seed multiplication is usually conducted by collecting seeds from farmer's fields so that the seed quality, especially for seeds purity level is very low. Improvements of seed quality is usually conducted through purification of exciting varieties, then, the result is released as a new variety. Other ways, some new varieties were improved through mutation breeding, for example, an early maturing mutant variety of Pandan Putri derived from irradiated Pandan Wangi variety from Cianjur area. The success story to reduce harvest age of Pandan Wangi variety through mutation breeding, it was triggers other local governments to use nuclear technology in improving agronomic traits of their local rice varieties, without altered another good characters. (author)

  6. Micronutrient-fortified rice can increase hookworm infection risk

    DEFF Research Database (Denmark)

    de Gier, Brechje; Campos Ponce, Maiza; Perignon, Marlene

    2016-01-01

    or inflammation after iron supplementation. OBJECTIVE: To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. METHODS: A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program....... Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice.......6%, but differed considerably among schools (range 0%- 48.1%).Micronutrient-fortified rice significantly increased risk of new hookworm infection. This effect was modified by baseline hookworm prevalence at the school; hookworm infection risk was increased by all three types of fortified rice in schools where...

  7. Nutrient management for rice production

    International Nuclear Information System (INIS)

    Khan, A.R.; Chandra, D.; Nanda, P.; Singh, S.S.; Singh, S.R.; Ghorai, A.K.

    2002-06-01

    The nutrient removed by the crops far exceeds the amounts replenished through fertilizer, causing a much greater strain on the native soil reserves. The situation is further aggravated in countries like India, where sub-optimal fertilizer used by the farmers is a common phenomenon rather than an exception. The total consumption of nutrients of all crops in India, even though reached 15 million tons in 1997, remains much below the estimated nutrient removal of 25 million tons (Swarup and Goneshamurthy, 1998). The gap between nutrient removal supplied through fertilizer has widened further in 2000 to 34 million tons of plant nutrients from the soil against an estimated fertilizer availability of 18 million tons (Singh and Dwivedi, 1996). Nitrogen is the nutrient which limits the most the rice production worldwide. In Asia, where more than 90 percent of the world's rice is produced, about 60 percent of the N fertilizer consumed is used on rice (Stangel and De Dutta, 1985). Conjunctive use of organic material along with fertilizer has been proved an efficient source of nitrogen. Organic residue recycling is becoming an increasingly important aspect of environmentally sound sustainable agriculture. Returning residues like green manure to the soil is necessary for maintaining soil organic matter, which is important for favourable soil structure, soil water retention and soil microbial flora and fauna activities. Use of organic manures in conjunction or as an alternative to chemical fertilizer is receiving attention. Green manure, addition to some extent, helps not only in enhancing the yield but also in improving the physical and chemical nature of soils. The excessive application of chemical fertilizers made it imperative that a part of inorganic fertilizer may be substituted with the recycling of organic wastes. Organic manure has been recorded to enhance the efficiency and reduce the requirement of chemical fertilizers. Partial nitrogen substitution through organic

  8. BGI-RIS: an integrated information resource and comparative analysis workbench for rice genomics

    DEFF Research Database (Denmark)

    Zhao, Wenming; Wang, Jing; He, Ximiao

    2004-01-01

    Rice is a major food staple for the world's population and serves as a model species in cereal genome research. The Beijing Genomics Institute (BGI) has long been devoting itself to sequencing, information analysis and biological research of the rice and other crop genomes. In order to facilitate....... Designed as a basic platform, BGI-RIS presents the sequenced genomes and related information in systematic and graphical ways for the convenience of in-depth comparative studies (http://rise.genomics.org.cn/). Udgivelsesdato: 2004-Jan-1...

  9. Bird poisoning from misuse of the carbamate Furadan in a Texas rice field

    Science.gov (United States)

    Flickinger, Edward L.; Mitchell, C.A.; White, D.H.; Kolbe, E.J.

    1986-01-01

    More than 100 birds consisting largely of dickcissels and savannah sparrows, as well as 9 other species of songbirds and sandpipers, died from feeding on planted rice seed treated illegally with Furadan 4F. Brain ChE activity was depressed between 32-85% in 44% of the birds. Carbofuran residues in GI tract contents of birds averaged 3.4 ppm (0.54-10 ppm). Two samples of planted rice seed contained 91 ppm and 22 ppm carbofuran. Known mortality of birds continued for about 2 weeks.

  10. An overview of the sustainability of rice agroecosystem through rice-fish integration

    International Nuclear Information System (INIS)

    Ahyaudin Ali

    2002-01-01

    Rice-fish integration in the rice agroecosystem has been introduced and is expanding in Malaysia. This type of farm integration has resulted in land optimization, thus enabling farmers to grow both fish and rice in one farming system. Introducing fish into the ricefield has also increased seasonal income as well as reduced pesticide use. Although basic ecological knowledge on rice-fish integration has allowed rice-fish integration to be introduced, further research is required to allow for fine tuning of the methodologies used. Thus research on the ecology, management, production methods and the characterization of rice-fish farming system of Malaysia is needed. Further characterization and description is needed on the ecology of the rice-fish farming system of Malaysia in terms of production, food webs, nutrient flow and system diversity. To increase the sustainability efficiency and productivity of the system, implementation of management techniques formulated through research is required. (Author)

  11. Residues and accumulation of molinate in rice crops and aquatic weeds in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Nashriyah Mat; Sabri Junoh; Nuriati Nurdin; Ramli Ishak

    2002-01-01

    Plant and soil residue levels and its accumulation in rice crops and rice aquatic weed plants were studied. Molinate residue levels in rice, weeds and soil were not significantly different between the recycled and the non-recycled area, even though they were higher in the non-recycled area. In the rice plant, the residue level at 10 DAT (days after treatment) was significantly higher than 30 DAT in the recycled area. In rice aquatic weed plants, the residue level was significantly higher at 10 DAT as compared to 30 DAT in the non-recycled area. Molinate residue levels in soil at 10 DAT and 30 DAT were similar. Molinate accumulated (ratio of molinate concentration in plant over soil) more in the rice crop as compared to rice aquatic weeds at 10 DAT, in both the recycled and the non-recycled areas. (Author)

  12. Effect of gamma irradiation on fungi in stored rice

    International Nuclear Information System (INIS)

    Zainal Abidin Mior Ahmad.

    1987-01-01

    The objective of this study is to examine the effect of different doses of gamma irradiation on fungi infecting rice stored in various packaging materials. The agar plate test method was used. It was observed that the percentage of fungi did not appear to decrease with the increase of irradiation up to 2 kGy and also no indication of any significant reduction in percentage of fungi isolated with increasing time of storage at all levels of radiation treatment. The majority of the fungi isolated were Aspergillus and Penicillium species. (A.J.)

  13. [Characterization and microbial community shifts of rice strawdegrading microbial consortia].

    Science.gov (United States)

    Wang, Chunfang; Ma, Shichun; Huang, Yan; Liu, Laiyan; Fan, Hui; Deng, Yu

    2016-12-04

    To study the relationship between microbial community and degradation rate of rice straw, we compared and analyzed cellulose-decomposing ability, microbial community structures and shifts of microbial consortia F1 and F2. We determined exoglucanase activity by 3, 5-dinitrosalicylic acid colorimetry. We determined content of cellulose, hemicellulose and lignin in rice straw by Van Soest method, and calculated degradation rates of rice straw by the weight changes before and after a 10-day incubation. We analyzed and compared the microbial communities and functional microbiology shifts by clone libraries, Miseq analysis and real time-PCR based on the 16S rRNA gene and cel48 genes. Total degradation rate, cellulose, and hemicellulose degradation rate of microbial consortia F1 were significantly higher than that of F2. The variation trend of exoglucanase activity in both microbial consortia F1 and F2 was consistent with that of cel48 gene copies. Microbial diversity of F1 was complex with aerobic bacteria as dominant species, whereas that of F2 was simple with a high proportion of anaerobic cellulose decomposing bacteria in the later stage of incubation. In the first 4 days, unclassified Bacillales and Bacillus were dominant in both F1 and F2. The dominant species and abundance became different after 4-day incubation, Bacteroidetes and Firmicutes were dominant phyla of F1 and F2, respectively. Although Petrimonas and Pusillimonas were common dominant species in F1 and F2, abundance of Petrimonas in F2 (38.30%) was significantly higher than that in F1 (9.47%), and the abundance of Clostridiales OPB54 in F2 increased to 14.85% after 8-day incubation. The abundance of cel48 gene related with cellulose degradation rate and exoglucanase activity, and cel48 gene has the potential as a molecular marker to monitor the process of cellulose degradation. Microbial community structure has a remarkable impact on the degradation efficiency of straw cellulose, and Petrimonas

  14. A maize resistance gene functions against bacterial streak disease in rice

    OpenAIRE

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-01-01

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, wh...

  15. Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils.

    Science.gov (United States)

    Wu, Fuyong; Hu, Junli; Wu, Shengchun; Wong, Ming Hung

    2015-06-01

    A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p rice production when growing in As-contaminated soils.

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

    Science.gov (United States)

    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

    2016-08-09

    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.

  17. Cross genome comparisons of serine proteases in Arabidopsis and rice

    Directory of Open Access Journals (Sweden)

    Sowdhamini R

    2006-08-01

    Full Text Available Abstract Background Serine proteases are one of the largest groups of proteolytic enzymes found across all kingdoms of life and are associated with several essential physiological pathways. The availability of Arabidopsis thaliana and rice (Oryza sativa genome sequences has permitted the identification and comparison of the repertoire of serine protease-like proteins in the two plant species. Results Despite the differences in genome sizes between Arabidopsis and rice, we identified a very similar number of serine protease-like proteins in the two plant species (206 and 222, respectively. Nearly 40% of the above sequences were identified as potential orthologues. Atypical members could be identified in the plant genomes for Deg, Clp, Lon, rhomboid proteases and species-specific members were observed for the highly populated subtilisin and serine carboxypeptidase families suggesting multiple lateral gene transfers. DegP proteases, prolyl oligopeptidases, Clp proteases and rhomboids share a significantly higher percentage orthology between the two genomes indicating substantial evolutionary divergence was set prior to speciation. Single domain architectures and paralogues for several putative subtilisins, serine carboxypeptidases and rhomboids suggest they may have been recruited for additional roles in secondary metabolism with spatial and temporal regulation. The analysis reveals some domain architectures unique to either or both of the plant species and some inactive proteases, like in rhomboids and Clp proteases, which could be involved in chaperone function. Conclusion The systematic analysis of the serine protease-like proteins in the two plant species has provided some insight into the possible functional associations of previously uncharacterised serine protease-like proteins. Further investigation of these aspects may prove beneficial in our understanding of similar processes in commercially significant crop plant species.

  18. Mobilization of retrotransposons in synthetic allotetraploid tobacco

    Czech Academy of Sciences Publication Activity Database

    Petit, M.; Guidat, C.; Daniel, J.; Montoriol, E.; Bui, Q.T.; Lim, K.Y.; Kovařík, Aleš; Leitch, A.R.; Grandbastien, M.-A.; Mhiri, C.

    2010-01-01

    Roč. 186, č. 1 (2010), s. 135-147 ISSN 0028-646X R&D Projects: GA MŠk(CZ) MEB020823; GA ČR(CZ) GA521/07/0116 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : allopolyploidy * evolution * retrotransposition Subject RIV: AQ - Safety, Health Protection, Human - Machine Impact factor: 6.516, year: 2010

  19. Novel gene expression tools for rice biotechnology

    Science.gov (United States)

    Biotechnology is an effective and important method of improving both quality and agronomic traits in rice. We are developing novel molecular tools for genetic engineering, with a focus on developing novel transgene expression control elements (i.e. promoters) for rice. A suite of monocot grass promo...

  20. Recent advances on bioactivities of black rice.

    Science.gov (United States)

    Dias, Aécio L de S; Pachikian, Barbara; Larondelle, Yvan; Quetin-Leclercq, Joëlle

    2017-11-01

    Black rice has been consumed for centuries in Asian countries such as China, Korea or Japan. Nowadays, extracts and derivatives are considered as beneficial functional foods because of their high content in several bioactive molecules such as anthocyanins, other phenolics and terpenoids. The purpose of this review is to summarize and discuss recent developments on black rice bioactivities. Some sterols and triterpenoids with potential anticancer properties already tested in vitro and in vivo have been isolated and identified from bran extracts of black rice. Protection against osteoporosis has been suggested for the first time for black rice extracts. Because of its antioxidant and anti-inflammatory properties, black rice also protects liver and kidney from injuries. One clinical study reported the interest of black rice in case of alcohol withdrawal. Several advances have been recently achieved on the understanding of the potential biological effects of black rice and its derivatives. They further confirm that black rice should be considered as a promising source of health-promoting functional foods targeting a large set of noninfectious diseases. However, more clinical studies are needed to support the findings highlighted in this review.

  1. Functional genomics strategies with transposons in rice

    NARCIS (Netherlands)

    Greco, R.

    2003-01-01

    Rice is a major staple food crop and a recognizedmonocotylenedousmodel plant from which gene function discovery is projected to contribute to improvements in a variety of cereals like wheat and maize. The recent release of rough drafts of the rice genome sequence for public

  2. 33 CFR 117.324 - Rice Creek.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge, mile...

  3. Soil quality assessment in rice production systems

    NARCIS (Netherlands)

    Rodrigues de Lima, A.C.

    2007-01-01

    In the state of Rio Grande do Sul, Brazil, rice production is one of the most important regional activities. Farmers are concerned that the land use practices for rice production in the Camaquã region may not be sustainable because of detrimental effects on soil quality. The study presented in this

  4. Land Titles and Rice Production in Vietnam

    DEFF Research Database (Denmark)

    Van Den Broeck, Katleen; Newman, Carol; Tarp, Finn

    analysis of plot level rice yields that land titles are indeed important. Only exclusively held titles have the expected positive effects, and the positive effect on yields is found in male headed households. Furthermore, a household level rice yield function reveals that exclusive user rights...

  5. Adoption of Recommended Rice Production Practices among ...

    African Journals Online (AJOL)

    User

    rice production practices by women farmers in Nasarawa State. A total of 203 women rice farmers were selected for the study using multi- ... RRPPs were unavailability of credit facilities, poor marketing system and ... economy which provides employment opportunity for about 70-80 percent of the total ..... shown in Table 1.

  6. Characterisation of the microbiota of rice sourdoughs and description of Lactobacillus spicheri sp. nov.

    Science.gov (United States)

    Meroth, Christiane B; Hammes, Walter P; Hertel, Christian

    2004-03-01

    The microbiota of two industrially processed rice sourdoughs was characterised by bacteriological culture in combination with PCR-denaturing gradient gel electrophoresis (DGGE) and 16S/28S rDNA sequence analysis. Rice sourdough I was continuously propagated for several years by back-slopping every week, whereas sourdough II was processed by using a commercial starter culture and back-slopping daily for three days. In rice sourdough II Candida krusei and Saccharomyces cerevisiae as well as Lactobacillus fermentum, Lactobacillus gallinarum, Lactobacillus kimchii, Lactobacillus plantarum, and Lactobacillus pontis dominated at the first day of fermentation. RAPD analysis of lactobacilli revealed identical profiles for each of the species except for L. fermentum and L. pontis indicating the presence of different strains. Fluctuations within the LAB community during fermentation were monitored by PCR-DGGE. L. pontis decreased in numbers over time and L. curvatus became dominant after 3 days of fermentation. Rice sourdough I contained S. cerevisiae, Lactobacillus paracasei (present with three different RAPD types), Lactobacillus paralimentarius, and a Lactobacillus strain which could not be allotted to any valid species. Phylogenetic analysis based on 16S rDNA sequences revealed Lactobacillus brevis as the closest relative (97.3% sequence similarity). Differences in some phenotypic characteristics and DNA-DNA relatedness indicated that the strain represents a new Lactobacillus species, for which the name Lactobacillus spicheri is proposed.

  7. Biodiversity Insects Used Three Traps Of Upland Rice Fields In Simalungun District

    Directory of Open Access Journals (Sweden)

    Ameilia Zuliyanti Siregar

    2017-02-01

    Full Text Available Rice and fish are the main food source for the peoples of Indonesia especially in Northern Sumatra. This research was done to determine biodiversity insects used by purposive random sampling from March until July 2016 which 3 traps yellow trap sweeping net and core sampler repeated five times in control and fish farming sites in Purwosari village Pematang Bandar Simalungun District Northern Sumatra Indonesia. The results showed the insects were caught on land fish-rice farming consist of 9 orders 40 families and 42 species 2028 individuals identified. From the research the fish farming has been done obtained the highest number of individuals insects caught used yellow trap are 1111 individuals followed by sweep net 800 individuals and the lower used the core sampler 117 individuals. Meanwhile 1288 individuals are highest of insects collected use by yellow trap followed by Sweep net 704 individuals and Core sampler 137 individuals. The value of species richness in rice-fish farming 5.384 index Margalef and 0.932 index Menhinick more than a value of species richness in control 5.089 index Margalef and 0.866 index Menhinick. The result value Index of Evenness in rice-fish farming 0.80 and control 0.78. The suitable traps for detected of biodiversity insects in paddy plantation and fish farming used the yellow trap..

  8. Effects of Transgenic cry1Ca Rice on the Development of Xenopus laevis.

    Directory of Open Access Journals (Sweden)

    Xiuping Chen

    Full Text Available In fields of genetically modified, insect-resistant rice expressing Bacillus thuringiensis (Bt proteins, frogs are exposed to Bt Cry proteins by consuming both target and non-target insects, and through their highly permeable skin. In the present study, we assessed the potential risk posed by transgenic cry1Ca rice (T1C-19 on the development of a frog species by adding purified Cry1Ca protein or T1C-19 rice straw into the rearing water of Xenopus laevis tadpoles, and by feeding X. laevis froglets diets containing rice grains of T1C-19 or its non-transformed counterpart MH63. Our results showed that there were no significant differences among groups receiving 100 μg L-1 or 10 μg L-1 Cry1Ca and the blank control in terms of time to completed metamorphosis, survival rate, body weight, body length, organ weight and liver enzyme activity after being exposed to the Cry1Ca (P > 0.05. Although some detection indices in the rice straw groups were significantly different from those of the blank control group (P < 0.05, there was no significant difference between the T1C-19 and MH63 rice straw groups. Moreover, there were no significant differences in the mortality rate, body weight, daily weight gain, liver and fat body weight of the froglets between the T1C-19 and MH63 dietary groups after 90 days, and there were no abnormal pathological changes in the stomach, intestines, livers, spleens and gonads. Thus, we conclude that the planting of transgenic cry1Ca rice will not adversely affect frog development.

  9. Tillering and panicle branching genes in rice.

    Science.gov (United States)

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. A spectral analysis of rice grains

    International Nuclear Information System (INIS)

    McIlvaine, M.S.; Cua, F.T.; Navarro, E.F.

    1976-06-01

    With the advent of extensive nuclear testing and the development and use of highly potent pesticides and fertilizers, the hazardous threats of radioactive contamination due to fallout and to the absorption of pesticide residues have been given due consideration. Among the many forms of life exposed to these threats are food crops and among these is rice. Several rice grain samples - Japanese rice samples ''A'' and ''B'' submitted by the National Grains Authority (NGA) for analysis, random samples of rice being sold to the public at local markets, and ''black rice'' which were picked from along the shores of a Mindoro town were subjected to spectral analysis. Results revealed the presence of trace elements normally found in plants, such as; K-42, I-124, Cl-38, Na-24, Br-82, and Mn-56. No mercury was detected in the sample specimen analyzed

  11. Rice epigenomics and epigenetics: challenges and opportunities.

    Science.gov (United States)

    Chen, Xiangsong; Zhou, Dao-Xiu

    2013-05-01

    During recent years rice genome-wide epigenomic information such as DNA methylation and histone modifications, which are important for genome activity has been accumulated. The function of a number of rice epigenetic regulators has been studied, many of which are found to be involved in a diverse range of developmental and stress-responsive pathways. Analysis of epigenetic variations among different rice varieties indicates that epigenetic modification may lead to inheritable phenotypic variation. Characterizing phenotypic consequences of rice epigenomic variations and the underlining chromatin mechanism and identifying epialleles related to important agronomic traits may provide novel strategies to enhance agronomically favorable traits and grain productivity in rice. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Transmission Biology of Rice Stripe Mosaic Virus by an Efficient Insect Vector Recilia dorsalis (Hemiptera: Cicadellidae

    Directory of Open Access Journals (Sweden)

    Xin Yang

    2017-12-01

    Full Text Available Rice stripe mosaic virus (RSMV is a newly discovered species of cytorhabdovirus infecting rice plants that is transmitted by the leafhopper Recilia dorsalis. In this study, the transmission characteristics of RSMV by R. dorsalis were investigated. Under suitable growth conditions for R. dorsalis, the RSMV acquisition rate reached 71.9% in the second-generation population raised on RSMV-infected rice plants. The minimum acquisition and inoculation access periods of R. dorsalis were 3 and 30 min, respectively. The minimum and maximum latent transmission periods of RSMV in R. dorsalis were 6 and 18 d, respectively, and some R. dorsalis intermittently transmitted RSMV at 2–6 d intervals. Our findings revealed that the virus can replicate in the leafhopper body, but is likely not transovarially transmitted to offspring. These transmission characteristics will help guide the formulation of RSMV prevention and control strategies.

  13. Chemometrical characterization of four italian rice varieties based on genetic and chemical analyses.

    Science.gov (United States)

    Brandolini, Vincenzo; Coïsson, Jean Daniel; Tedeschi, Paola; Barile, Daniela; Cereti, Elisabetta; Maietti, Annalisa; Vecchiati, Giorgio; Martelli, Aldo; Arlorio, Marco

    2006-12-27

    This paper describes a method for achieving qualitative identification of four rice varieties from two different Italian regions. To estimate the presence of genetic diversity among the four rice varieties, we used polymerase chain reaction-randomly amplified polymorphic DNA (PCR-RAPD) markers, and to elucidate whether a relationship exists between the ground and the specific characteristics of the product, we studied proximate composition, fatty acid composition, mineral content, and total antioxidant capacity. Using principal component analysis on genomic and compositional data, we were able to classify rice samples according to their variety and their district of production. This work also examined the discrimination ability of different parameters. It was found that genomic data give the best discrimination based on varieties, indicating that RAPD assays could be useful in discriminating among closely related species, while compositional analyses do not depend on the genetic characters only but are related to the production area.

  14. Recent progress on the genetics and molecular breeding of brown planthopper resistance in rice.

    Science.gov (United States)

    Hu, Jie; Xiao, Cong; He, Yuqing

    2016-12-01

    Brown planthopper (BPH) is the most devastating pest of rice. Host-plant resistance is the most desirable and economic strategy in the management of BPH. To date, 29 major BPH resistance genes have been identified from indica cultivars and wild rice species, and more than ten genes have been fine mapped to chromosome regions of less than 200 kb. Four genes (Bph14, Bph26, Bph17 and bph29) have been cloned. The increasing number of fine-mapped and cloned genes provide a solid foundation for development of functional markers for use in breeding. Several BPH resistant introgression lines (ILs), near-isogenic lines (NILs) and pyramided lines (PLs) carrying single or multiple resistance genes were developed by marker assisted backcross breeding (MABC). Here we review recent progress on the genetics and molecular breeding of BPH resistance in rice. Prospect for developing cultivars with durable, broad-spectrum BPH resistance are discussed.

  15. Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

    Directory of Open Access Journals (Sweden)

    Juliano de Bastos Pazini

    2016-09-01

    Full Text Available Telenomus and Trichogramma species stand out as agents for the biological control in rice crops, and the main strategy for preserving them is the use of selective pesticides. This study aimed at evaluating the toxicity of pesticides used in irrigated rice crop on Telenomus podisi Ashmead (Hymenoptera: Platygastridae and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae. Adults of these parasitoids were exposed to dry residues of pesticides, in a completely randomized experiment, with 25 treatments (24 pesticides + control and four replications. The insecticides clorantraniliprole, flubendiamide and diflubenzuron and the biological insecticides based on Beauveria bassiana and Metarhizium anisopliae were harmless to T. podisi and T. pretiosum. The harmless herbicides were: 2.4-D amine, profoxydim, quinclorac, ethoxysulfuron and saflufenacil. The fungicide epoxiconazole + kresoxim-methyl was also harmless to these two biological control agents. Therefore, these pesticides are indicated for the integrated pest management, in flooded rice areas.

  16. Fluoride levels in commercially available rice in Ethiopia | Tegegne ...

    African Journals Online (AJOL)

    Alkaline fusion was used for sample preparation of six varieties for both the raw rice and rice cooked with tap water and fluoridated water. Fluoride levels ranged from 0.1-5.5 mg/kg in raw rice sample. Rice which was cooked with different fluoride levels of water showed increment depending on the method of cooking.

  17. Signatures of adaptation in the weedy rice genome

    Science.gov (United States)

    Weedy rice is a common problem of by product of domestication that has evolved multiple times from cultivated and wild rice relatives. Here we use whole genome sequences to examine the origin and adaptation of the two major US weedy red rice strains, with a comparison to Chinese weedy red rice. We f...

  18. The economic power of the Golden Rice opposition

    NARCIS (Netherlands)

    Wesseler, J.H.H.; Zilberman, D.

    2014-01-01

    Vitamin A enriched rice (Golden Rice) is a cost-efficient solution that can substantially reduce health costs. Despite Golden Rice being available since early 2000, this rice has not been introduced in any country. Governments must perceive additional costs that overcompensate the benefits of the

  19. Significance of rice sheath photosynthesis: Yield determination by ...

    African Journals Online (AJOL)

    Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these ...

  20. Genomic diversity among Basmati rice ( Oryza sativa L) mutants ...

    African Journals Online (AJOL)

    Mutation breeding can be considered successful in obtaining new cultivars and broadening the genetic base of rice crop. In order to obtain new varieties of rice with improved agronomic and grain characteristics, gamma radiation (60Co) has been used to generate novel mutants of the Basmati rice. In this study rice cultivars ...

  1. 7 CFR 868.301 - Definition of milled rice.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of milled rice. 868.301 Section 868.301... FOR CERTAIN AGRICULTURAL COMMODITIES United States Standards for Milled Rice Terms Defined § 868.301 Definition of milled rice. Whole or broken kernels of rice (Oryza sativa L.) from which the hulls and at...

  2. 7 CFR 868.201 - Definition of rough rice.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of rough rice. 868.201 Section 868.201... FOR CERTAIN AGRICULTURAL COMMODITIES United States Standards for Rough Rice Terms Defined § 868.201 Definition of rough rice. Rice (Oryza sativa L.) which consists of 50 percent or more of paddy kernels (see...

  3. 21 CFR 573.160 - Ammoniated rice hulls.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ammoniated rice hulls. 573.160 Section 573.160... Additive Listing § 573.160 Ammoniated rice hulls. The food additive ammoniated rice hulls may be safely... obtained by the treatment of ground rice hulls with monocalcium phosphate and anhydrous ammonia at a...

  4. Rice field for the treatment of pond aquaculture effluents | Wang ...

    African Journals Online (AJOL)

    We conducted an experiment to evaluate the efficiency of rice fields in treating pond aquaculture effluent and its responses to different fertilizer treatments. Four treatments was considered in the experiment: no rice planted as the control (CT); rice planted and no fertilizer input (RE); rice planted and a rate of approximately ...

  5. Questioning triple rice intensification on the Vietnamese mekong delta floodplains

    NARCIS (Netherlands)

    Tran, Dung Duc; Halsema, van Gerardo; Hellegers, Petra J.G.J.; Ludwig, Fulco; Wyatt, Andrew

    2018-01-01

    Large areas of the Vietnamese Mekong Delta floodplains (VMDF) are protected by high dikes to facilitate three rice crops per year. While this has increased rice production, there is evidence that triple rice systems have negative long-term effects, both environmental and economic. Double rice

  6. Does African catfish ( Clarias gariepinus ) affect rice in integrated ...

    African Journals Online (AJOL)

    An experiment was conducted for 98 days in the Lake Victoria Basin to investigate the interactions of fish and rice growth performance in rice paddies. The experiment was laid out in a split-plot design, with rice cultivar as the main plot and method of rice-fish culture as the sub-plot. Treatments consisted of two levels of ...

  7. EFFECT OF ALUMINUM ON PLANT GROWTH, PHOSPORUS AND CALCIUM UPTAKE OF TROPICAL RICE (Oryza sativa, MAIZE (Zea mays, AND SOYBEAN (Glycine max

    Directory of Open Access Journals (Sweden)

    D. Nursyamsi

    2018-01-01

    Full Text Available Aluminum toxicity is the most limiting factor to plant growth on acid soils. Structural and functional damages in the root system by Al decrease nutrient uptake and lead to reduce plant growth and mineral deficiency in shoot. Greenhouse experiment was conducted to study the effect of Al on plant growth, and P and Ca uptake of rice, maize, and soybean. The plants were grown in hydroponic solution added with 0, 5, 10, and 30 ppm Al, at pH 4.0. The results showed that relative growth of shoots and roots of upland rice, lowland rice, maize, and soybean decreased with an increase of Al level. However, sometimes the low Al level (5 ppm stimulated shoot and root growth of some varieties in these species. According to total AlRG30 values, which is Al concentration in solution when relative growth decreased to 50%, Al tolerance of species was in order of barley < maize < soybean < lowland rice < upland rice. For maize, Al tolerance was in the order of Arjuna < Kalingga < P 3540 < SA 5 < SA 4 < PM 95 A < SA 3 < Antasena; for soybean was Wilis < INPS < Galunggung < Kerinci < Kitamusume; for lowland rice was RD 23 < Kapuas < Cisadane < KDML 105 < IR 66 < RD 13, and for upland rice was Dodokan < JAC165 < Cirata < Orizyca sabana 6 < Danau Tempe < Laut Tawar. Based on the rank of Al tolerance, rice was the useful crop to be planted in acid soils. Antasena (maize, Kitamusume ( soybean , RD 13 (lowland rice, and Laut Tawar (upland rice were also recommended for acid soils. P and Ca concentration in shoots and roots commonly decreased with an increase of Al level. However, the low Al level stimulated absorption of P and Ca concentrations in shoots and roots.

  8. Imazethapyr and imazapic, bispyribac-sodium and penoxsulam: Zooplankton and dissipation in subtropical rice paddy water

    Energy Technology Data Exchange (ETDEWEB)

    Reimche, Geovane B., E-mail: geovane_reimche@yahoo.com.br [Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS (Brazil); Machado, Sérgio L.O. [Department of Plant Protection, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS (Brazil); Oliveira, Maria Angélica [Department of Biology, Federal University of Santa Maria, Santa Maria, RS (Brazil); Zanella, Renato; Dressler, Valderi Luiz; Flores, Erico M.M. [Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS (Brazil); Gonçalves, Fábio F. [School of Chemistry and Food, Federal Foundation University of Rio Grande (FURG), 95500-000 Santo Antônio da Patrulha, RS (Brazil); Donato, Filipe F.; Nunes, Matheus A.G. [Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS (Brazil)

    2015-05-01

    Herbicides are very effective at eliminating weed and are largely used in rice paddy around the world, playing a fundamental role in maximizing yield. Therefore, considering the flooded environment of rice paddies, it is necessary to understand the side effects on non-target species. Field experiment studies were carried out during two rice growing seasons in order to address how the commonly-used herbicides imazethapyr and imazapic, bispyribac-sodium and penoxsulam, used at recommended dosage, affect water quality and the non-target zooplankton community using outdoor rice field microcosm set-up. The shortest (4.9 days) and longest (12.2 days) herbicide half-life mean, estimated of the dissipation rate (k) is shown for imazethapyr and bispyribac-sodium, respectively. Some water quality parameters (pH, conductivity, hardness, BOD{sub 5}, boron, potassium, magnesium, phosphorus and chlorides) achieved slightly higher values at the herbicide treatment. Zooplankton community usually quickly recovered from the tested herbicide impact. Generally, herbicides led to an increase of cladocera, copepods and nauplius population, while rotifer population decreased, with recovery at the end of the experiment (88 days after herbicide treatment). - Highlights: • Selective herbicides in paddy rice fields, do not affect water quality. • Zooplankton communities show good response with herbicide dissipation. • The use of commercial herbicide mixture has strong effects on freshwater Rotifers.

  9. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus

    Directory of Open Access Journals (Sweden)

    Fangquan Wang

    2016-05-01

    Full Text Available Rice black-streaked dwarf virus (RBSDV belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21–24 nt small interfering RNA (siRNA. By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.

  10. Hairpin RNA Targeting Multiple Viral Genes Confers Strong Resistance to Rice Black-Streaked Dwarf Virus.

    Science.gov (United States)

    Wang, Fangquan; Li, Wenqi; Zhu, Jinyan; Fan, Fangjun; Wang, Jun; Zhong, Weigong; Wang, Ming-Bo; Liu, Qing; Zhu, Qian-Hao; Zhou, Tong; Lan, Ying; Zhou, Yijun; Yang, Jie

    2016-05-11

    Rice black-streaked dwarf virus (RBSDV) belongs to the genus Fijivirus in the family of Reoviridae and causes severe yield loss in rice-producing areas in Asia. RNA silencing, as a natural defence mechanism against plant viruses, has been successfully exploited for engineering virus resistance in plants, including rice. In this study, we generated transgenic rice lines harbouring a hairpin RNA (hpRNA) construct targeting four RBSDV genes, S1, S2, S6 and S10, encoding the RNA-dependent RNA polymerase, the putative core protein, the RNA silencing suppressor and the outer capsid protein, respectively. Both field nursery and artificial inoculation assays of three generations of the transgenic lines showed that they had strong resistance to RBSDV infection. The RBSDV resistance in the segregating transgenic populations correlated perfectly with the presence of the hpRNA transgene. Furthermore, the hpRNA transgene was expressed in the highly resistant transgenic lines, giving rise to abundant levels of 21-24 nt small interfering RNA (siRNA). By small RNA deep sequencing, the RBSDV-resistant transgenic lines detected siRNAs from all four viral gene sequences in the hpRNA transgene, indicating that the whole chimeric fusion sequence can be efficiently processed by Dicer into siRNAs. Taken together, our results suggest that long hpRNA targeting multiple viral genes can be used to generate stable and durable virus resistance in rice, as well as other plant species.

  11. Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

    Science.gov (United States)

    Semsang, Nuananong; Yu, LiangDeng

    2013-07-01

    Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29-60 keV and ion fluences of 1 × 1016 ions cm-2. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

  12. Spider assemblages associated with different crop stages of irrigated rice agroecosystems from eastern Uruguay.

    Science.gov (United States)

    Bao, Leticia; Ginella, Juaquín; Cadenazzi, Mónica; Castiglioni, Enrique A; Martínez, Sebastián; Casales, Luis; Caraballo, María P; Laborda, Álvaro; Simo, Miguel

    2018-01-01

    The rice crop and associated ecosystems constitute a rich mosaic of habitats that preserve a rich biological diversity. Spiders are an abundant and successful group of natural predators that are considered efficient in the biocontrol of the major insect pests in agroecosystems. Spider diversity in different stages of the rice crop growth from eastern Uruguay was analysed. Field study was developed on six rice farms with rotation system with pasture, installed during intercropping stage as cover crop. Six rice crops distributed in three locations were sampled with pitfall and entomological vaccum suction machine. Sixteen families, representing six guilds, were collected. Lycosidae, Linyphiidae, Anyphaenidae and Tetragnathidae were the most abundant families (26%, 25%, 20% and 12%, respectively) and comprised more than 80% of total abundance. Other hunters (29%), sheet web weavers (25%) and ground hunters (24%) were the most abundant guilds. Species composition along different crop stages was significantly different according to the ANOSIM test. The results showed higher spider abundance and diversity along the crop and intercrop stages. This study represents the first contribution to the knowledge of spider diversity associated with rice agroecosystem in the country.

  13. Influence of aspartic acid and lysine on the uptake of gold nanoparticles in rice.

    Science.gov (United States)

    Ye, Xinxin; Li, Hongying; Wang, Qingyun; Chai, Rushan; Ma, Chao; Gao, Hongjian; Mao, Jingdong

    2018-02-01

    The interactions between plants and nanomaterials (NMs) can shed light on the environmental consequences of nanotechnology. We used the major crop plant rice (Oryza sativa L.) to investigate the uptake of gold nanoparticles (GNPs) coated with either negatively or positively charged ligands, over a 5-day period, in the absence or presence of one of two amino acids, aspartic acid (Asp) or lysine (Lys), acting as components of rice root exudates. The presence of Asp or Lys influenced the uptake and distribution of GNPs in rice, which depended on the electrical interaction between the coated GNPs and each amino acid. When the electrical charge of the amino acid was the same as that of the surface ligand coated onto the GNPs, the GNPs could disperse well in nutrient solution, resulting in increased uptake of GNPs into rice tissue. The opposite was true where the charge on the surface ligand was different from that on the amino acid, resulting in agglomeration and reduced Au uptake into rice tissue. The behavior of GNPs in the hydroponic nutrient solution was monitored in terms of agglomeration, particle size distribution, and surface charge in the presence and absence of Asp or Lys, which depended strongly on the electrostatic interaction. Results from this study indicated that the species of root exudates must be taken into account in assessing the bioavailability of nanomaterials to plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Physicochemical and Antioxidant Properties of Rice Bran Oils Produced from Colored Rice Using Different Extraction Methods.

    Science.gov (United States)

    Mingyai, Sukanya; Kettawan, Aikkarach; Srikaeo, Khongsak; Singanusong, Riantong

    2017-06-01

    This study investigated the physicochemical and antioxidant properties of rice bran oil (RBO) produced from the bran of three rice varities; Khao Dawk Mali 105 (white rice), Red Jasmine rice (red rice) and Hom-nin rice (black rice) using three extraction methods including cold-press extraction (CPE), solvent extraction (SE) and supercritical CO 2 extraction (SC-CO 2 ). Yields, color, acid value (AV), free fatty acid (FFA), peroxide value (PV), iodine value (IV), total phenolic compound (TPC), γ-oryzanol, α-tocopherol and fatty acid profile were analyzed. It was found that the yields obtained from SE, SC-CO 2 and CPE extractions were 17.35-20.19%, 14.76-18.16% and 3.22-6.22%, respectively. The RBO from the bran of red and black rice samples exhibited high antioxidant activities. They also contained higher amount of γ-oryzanol and α-tocopherol than those of white rice sample. In terms of extraction methods, SC-CO 2 provided better qualities of RBO as evidenced by their physicochemical and antioxidant properties. This study found that RBO produced from the bran of black rice samples using SC-CO 2 extraction method showed the best physicochemical and antioxidant properties.

  15. The Caryopsis of Red-Grained Rice Has Enhanced Resistance to Fungal Attack

    Directory of Open Access Journals (Sweden)

    Alberto Gianinetti

    2018-06-01

    Full Text Available Seed persistence in the soil is threatened by microorganisms, but the seed coat helps protect the seed from them. Although modern rice (Oryza sativa L. cultivars have a whitish caryopsis, some varieties have a red caryopsis coat, a trait typical of wild Oryza species. The red colour is due to the oxidation of proanthocyanidins, a class of flavonoids that is found in the outer layers of the seed in many species. We aimed to assess whether these natural compounds (proanthocyanidins and proanthocyanidin-derived pigment have some protective effect against microbial attacks. Dehulled caryopses of white-grained and red-grained rice genotypes were employed to assay fungal infection. Specifically, three white-grained rice cultivars (Perla, Augusto, and Koral and three red-grained rice varieties (Perla Rosso, Augusto Rosso, and Koral Rosso were used. In a first test, the caryopses were infected with Epicoccum nigrum at 10 °C, and seedling growth was then assessed at 30 °C. In a second test, the degree of infection by the mycotoxigenic fungus Fusarium sporotrichioides was assayed by measuring the accumulation of T-2/HT-2 toxins in the caryopses. Infection was performed at 10 °C to prevent rice germination while allowing fungal growth. In both the tests, red caryopses showed reduced, or delayed, infection with respect to white ones. One black-grained cultivar (Venere was assayed for the accumulation of T-2/HT-2 toxins as well, with results corresponding to those of the red-grained rice varieties. We argue that the red pigment accumulating in the caryopsis coat, and/or the proanthocyanidins associated with it, provides a protective barrier against challenging microorganisms.

  16. Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

    Energy Technology Data Exchange (ETDEWEB)

    Semsang, Nuananong, E-mail: nsemsang@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, LiangDeng [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► Ion beam bombarded rice seeds in vacuum. ► Studied seed survival from the ion bombardment. ► Determined various antioxidant enzyme activities and lipid peroxidation level. ► Discussed vacuum, ion species and ion energy effects. ► Attributed the changes to free radical formation due to ion bombardment. -- Abstract: Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29–60 keV and ion fluences of 1 × 10{sup 16} ions cm{sup −2}. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

  17. Isotopic tracer aided studies of fenvalerate residues in stored rice

    International Nuclear Information System (INIS)

    Varca, L.M.; Sanchez, T.E.; Magallona, E.D.

    1990-01-01

    Following application of 14 C-fenvalerate to milled rice and paddy rice at a concentration of 0.33 mg/kg, only insignificant losses were measured after 9 months. Distribution patterns in surface, methanol extractable and bound residues were studied. Paddy rice contained less extractable residues than milled rice, with the major part being found in the husk. Bound residues in both milled and paddy rice decreased also with length of storage; as much as 30% was found as bound residues after nine months. Cooking reduced the insecticide residues in milled rice by 33-40% and residues in paddy rice by 58%. (author). 8 refs, 1 fig., 4 tabs

  18. Engineered Dwarf Male-Sterile Rice: A Promising Genetic Tool for Facilitating Recurrent Selection in Rice.

    Science.gov (United States)

    Ansari, Afsana; Wang, Chunlian; Wang, Jian; Wang, Fujun; Liu, Piqing; Gao, Ying; Tang, Yongchao; Zhao, Kaijun

    2017-01-01

    Rice is a crop feeding half of the world's population. With the continuous raise of yield potential via genetic improvement, rice breeding has entered an era where multiple genes conferring complex traits must be efficiently manipulated to increase rice yield further. Recurrent selection is a sound strategy for manipulating multiple genes and it has been successfully performed in allogamous crops. However, the difficulties in emasculation and hand pollination had obstructed efficient use of recurrent selection in autogamous rice. Here, we report development of the dwarf male-sterile rice that can facilitate recurrent selection in rice breeding. We adopted RNAi technology to synergistically regulate rice plant height and male fertility to create the dwarf male-sterile rice. The RNAi construct pTCK-EGGE, targeting the OsGA20ox2 and OsEAT1 genes, was constructed and used to transform rice via Agrobacterium -mediated transformation. The transgenic T0 plants showing largely reduced plant height and complete male-sterile phenotypes were designated as the dwarf male-sterile plants. Progenies of the dwarf male-sterile plants were obtained by pollinating them with pollens from the wild-type. In the T1 and T2 populations, half of the plants were still dwarf male-sterile; the other half displayed normal plant height and male fertility which were designated as tall and male-fertile plants. The tall and male-fertile plants are transgene-free and can be self-pollinated to generate new varieties. Since emasculation and hand pollination for dwarf male-sterile rice plants is no longer needed, the dwarf male-sterile rice can be used to perform recurrent selection in rice. A dwarf male-sterile rice-based recurrent selection model has been proposed.

  19. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    International Nuclear Information System (INIS)

    Navedo, Juan G.; Hahn, Steffen; Parejo, Manuel; Abad-Gómez, José M.; Gutiérrez, Jorge S.; Villegas, Auxiliadora; Sánchez-Guzmán, Juan M.; Masero, José A.

    2015-01-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m −2 , with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m −2 in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha −1 ) of N and an additional 5.0 tons (0.2 kg·ha −1 ) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important for the

  20. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    Energy Technology Data Exchange (ETDEWEB)

    Navedo, Juan G., E-mail: jgnavedo@uach.cl [Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Facultad de Ciencias, Campus Isla Teja, 5090000 Valdivia (Chile); Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Hahn, Steffen [Department Bird Migration, Swiss Ornithological Institute, Seerose 1, 6204 Sempach (Switzerland); Parejo, Manuel; Abad-Gómez, José M. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Gutiérrez, Jorge S. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel (Netherlands); Villegas, Auxiliadora; Sánchez-Guzmán, Juan M.; Masero, José A. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain)

    2015-04-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m{sup −2}, with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m{sup −2} in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha{sup −1}) of N and an additional 5.0 tons (0.2 kg·ha{sup −1}) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important

  1. Consumer Preferences and Buying Criteria in Rice: A Study to Identify Market Strategy for Thailand Jasmine Rice Export

    NARCIS (Netherlands)

    Suwannaporn, P.; Linnemann, A.R.

    2008-01-01

    Rice consumption per capita in many Asian countries decreased, but it is consumed more in non-rice-eating countries. This study aimed to investigate consumer preferences and attitudes toward Jasmine rice among consumers in target rice export countries to identify opportunities and strategic

  2. The mitochondrial gene orfH79 plays a critical role in impairing both male gametophyte development and root growth in CMS-Honglian rice.

    Science.gov (United States)

    Peng, Xiaojue; Wang, Kun; Hu, Chaofeng; Zhu, Youlin; Wang, Ting; Yang, Jing; Tong, Jiping; Li, Shaoqing; Zhu, Yingguo

    2010-06-24

    Cytoplasmic male sterility (CMS) has often been associated with abnormal mitochondrial open reading frames. The mitochondrial gene orfH79 is a candidate gene for causing the CMS trait in CMS-Honglian (CMS-HL) rice. However, whether the orfH79 expression can actually induce CMS in rice remains unclear. Western blot analysis revealed that the ORFH79 protein is mainly present in mitochondria of CMS-HL rice and is absent in the fertile line. To investigate the function of ORFH79 protein in mitochondria, this gene was fused to a mitochondrial transit peptide sequence and used to transform wild type rice, where its expression induced the gametophytic male sterile phenotype. In addition, excessive accumulation of reactive oxygen species (ROS) in the microspore, a reduced ATP/ADP ratio, decreased mitochondrial membrane potential and a lower respiration rate in the transgenic plants were found to be similar to those in CMS-HL rice. Moreover, retarded growth of primary and lateral roots accompanied by abnormal accumulation of ROS in the root tip was observed in both transgenic rice and CMS-HL rice (YTA). These results suggest that the expression of orfH79 in mitochondria impairs mitochondrial function, which affects the development of both male gametophytes and the roots of CMS-HL rice.

  3. Mutant-inducing effect of γ-ray irradiation for hybrid rice F1 derived from cross of black glutinous rice x wild rice

    International Nuclear Information System (INIS)

    Mao Dezhi; Tang Yilan

    1998-01-01

    The hybrid rice F 1 plant derived from the back crossing of glutinous rice x wild rice was irradiated with γ-ray. The result of investigation to the induced mutant showed that through the selection and backcross, a black glutinous rice strain with the short stem, cold tolerance and high yield was developed. The analysis of the ability of heredity variance showed that the selection was effective for the husk colour, black glutinous and black Indica rice, but ineffective for the white Indica rice and seed setting

  4. Influence of sulfur on the accumulation of mercury in rice plant (Oryza sativa L.) growing in mercury contaminated soils.

    Science.gov (United States)

    Li, Yunyun; Zhao, Jiating; Guo, Jingxia; Liu, Mengjiao; Xu, Qinlei; Li, Hong; Li, Yu-Feng; Zheng, Lei; Zhang, Zhiyong; Gao, Yuxi

    2017-09-01

    Sulfur (S) is an essential element for plant growth and its biogeochemical cycling is strongly linked to the species of heavy metals in soil. In this work, the effects of S (sulfate and elemental sulfur) treatment on the accumulation, distribution and chemical forms of Hg in rice growing in Hg contaminated soil were investigated. It was found that S could promote the formation of iron plaque on the root surface and decrease total mercury (T-Hg) and methylmercury (MeHg) accumulation in rice grains, straw, and roots. Hg in the root was dominated in the form of RS-Hg-SR. Sulfate treatment increased the percentage of RS-Hg-SR to T-Hg in the rice root and changed the Hg species in soil. The dominant Hg species (70%) in soil was organic substance bound fractions. Sulfur treatment decreased Hg motility in the rhizosphere soils by promoting the conversion of RS-Hg-SR to HgS. This study is significant since it suggests that low dose sulfur treatment in Hg-containing water irrigated soil can decrease both T-Hg and MeHg accumulation in rice via inactivating Hg in the soil and promoting the formation of iron plaque in rice root, which may reduce health risk for people consuming those crops. Copyright © 2017. Published by Elsevier Ltd.

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

    Directory of Open Access Journals (Sweden)

    Louca Vasilis

    2009-07-01

    Full Text Available Abstract 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

  6. Evaluation of Heavy Metals Contamination from Environment to Food Matrix by TXRF: The Case of Rice and Rice Husk

    Directory of Open Access Journals (Sweden)

    Fabjola Bilo

    2015-01-01

    Full Text Available This paper is devoted to the chemical analysis of contaminated soils of India and the rice grown in the same area. Total reflection X-ray fluorescence spectroscopy is a well-established technique for elemental chemical analysis of environmental samples, and it can be a useful tool to assess food safety. Metals uptake in rice crop grown in soils from different areas was studied. In this work soil, rice husk and rice samples were analyzed after complete solubilization of samples by microwave acid digestion. Heavy metals concentration detected in rice samples decreases in the following order: Mn > Zn > Cu > Ni > Pb > Cr. The metal content in rice husk was higher than in rice. This study suggests, for the first time, a possible role of heavy metals filter played by rice husk. The knowledge of metals sequestration capability of rice husk may promote some new management practices for rice cultivation to preserve it from pollution.

  7. [Quality of pastas supplemented with rice bran].

    Science.gov (United States)

    Sangronis, E; Rebolledo, M A

    1997-06-01

    The objective of this research was to investigate the potential of using rice bran as an ingredient in pastas spaghetti type. Two of the pastas were made with semolina from durum as raw material, supplemented with 10 and 20% rice bran. The other two were made with granular flour and the same percentage of rice bran. Proximate composition of raw material was analyzed. Pastas were elaborated in a local industry. Composition, proximal, color, texture, and sensorial quality of pastas were determined. Protein content (13.9-15.0%), ash (1.47-3.09%) and dietary fiber (6.71-8.45%) of pastas increased according to the percentage of rice bran added. The hardest pastas were those elaborated with semolina from durum wheat and with a 10% of substitution. Also, they were the most yellow. The sensory panel found differences in quality among the pastas evaluated. Pastas with 10% rice bran had the best quality. The results demonstrated that is possible to elaborate pastas with 20% as maximum of rice bran resulting products with high protein, ash and dietetic fiber content, but some undesirable characteristics were given by the rice bran as white spots, wrinkles and color changes.

  8. Using rice straw to manufacture ceramic bricks

    Directory of Open Access Journals (Sweden)

    Gorbunov German Ivanovich

    2014-12-01

    Full Text Available In the article, the co-authors offer their advanced and efficient methodologies for the recycling of the rice straw, as well as the novel approaches to the ceramic brick quality improvement through the application of the rice straw as the combustible additive and through the formation of amorphous silica in the course of the rice straw combustion. The co-authors provide characteristics of the raw materials, production techniques used to manufacture ceramic bricks, and their basic properties in the article. The co-authors describe the simulated process of formation of amorphous silica. The process in question has two independent steps (or options: 1 rice straw combustion and ash formation outside the oven (in the oxidizing medium, and further application of ash as the additive in the process of burning clay mixtures; 2 adding pre-treated rice straw as the combustible additive into the clay mixture, and its further burning in compliance with the pre-set temperature mode. The findings have proven that the most rational pre-requisite of the rice straw application in the manufacturing of ceramic bricks consists in feeding milled straw into the clay mixture to be followed by molding, drying and burning. Brick samples are highly porous, and they also demonstrate sufficient compressive strength. The co-authors have also identified optimal values of rice straw and ash content in the mixtures under research.

  9. Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

    Science.gov (United States)

    Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

    2017-08-01

    Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

  10. A rice husk gasifier for paddy drying

    International Nuclear Information System (INIS)

    Mirani, A.A.; Kalwar, S.A.; Ahmad, M.

    2013-01-01

    Due to energy crisis and constant increase in the price of fossil fuels, the world's trend changes to renewable sources of energy like solar, wind and biomass gasification. Substantial biomass potential is available in Pakistan in the form of agriculture or forest residue (rice straw, rice husk, cotton stalks, corn cobs, wood chips, wood saw, etc.). These can be best utilised for the production of producer gas or synthetic gas that can be used for drying of agricultural crops. The drying process is an important activity of post harvest processing for long-term storage. Rice husk is nowadays commonly used for biomass gasification and its heat content value is about 15MJ/kg. It constitutes about 30 percent of rice production. A rice husk gasifier was developed and evaluated on paddy drying at Japan International Cooperation Agency (JICA), Tsukuba International Center (TBIC), Japan. Rice husk gasifier has following major components; husk feeding system, ash chamber, burner, centrifugal fan, drying chamber, gasifier reactor, air duct and an electric motor of 0.37kW. The average drying plenum air temperature was recorded as 45 degree C during the drying process. The paddy 'IR 28' from initial moisture content of 24% was dried up to 14% moisture content for about 3.33h consuming 3kg/h of rice husk. The efficiency was found to be 58%. The rice husk gasifier can also be used for drying the fruits and vegetables, provided that heat exchanger should be attached with it. The overall performance of rice husk gasifier was satisfactory and will be beneficial for small scale farmers, food processors and millers as well. (author)

  11. Change in Localizations of Arsenic in Rice Grains After Cooking with High Arsenic Waters - µXRF and XANES studies

    Science.gov (United States)

    Datta, S.; Ryan, B.; Kumar, N.; Bortz, T.; Bolen, Z. T.

    2016-12-01

    Threats of Arsenic (As) through food uptake, via consumption of rice, is a potential pathway that presents a concern not only for the millions of inhabitants who reside in river valleys and irrigate their soil with contaminated water, but the global rice market as well. This study focuses on high As rice from India and Bangladesh grown in such soils, and the effect of boiling rice with As-contaminated water in preparation for dietary intake. Husked and unhusked rice grains were boiled with >500 µg/L As-bearing water from the field to simulate local cooking methods. The resulting cooked water was analyzed using iCAP low limit detection via ICP-MS to understand the changes in dissolved elemental concentrations before and after cooking, and HPLC was introduced to measure for changes in As speciation in the waters. Using spectroscopic methods such as µXRF mapping associated with µXANES, distribution/localization and speciation changes of As in rice grains were identified. Further, with Linear Combination Fitting (LCF) of XANES spectra utilizing relevant reference compounds (As-S, AsIII, AsV, MMA and DMA), organic and inorganic As species were able to be mapped within rice grains. The results for uncooked/raw grains showed that predominantly As-S combined with AsIII and AsV accounted for 90% of speciation in most samples, localized in areas such as the outer aleurone layer. When analyzing cooked rice grains, the speciation appears to be an unidentified As species while the best LCF shows between 63-93% of As as MMA. Arsenic was found less localized throughout the cooked grains but rather heterogeneously distributed when compared to the uncooked/raw samples. The analyses of boiled/cooked water resulted in a significant decrease in dissolved As post-cooking (90%), but a subsequent increase in elements such as K, La, Li, Mo, Na, Ni, and Zr was observed; As-V was shown to be the main in-As species in the cooked water. The impact that this study portrays is consuming rice

  12. Wolbachia infection complexity among insects in the tropical rice-field community.

    Science.gov (United States)

    Kittayapong, P; Jamnongluk, W; Thipaksorn, A; Milne, J R; Sindhusake, C

    2003-04-01

    Wolbachia are a group of intracellular bacteria that cause reproductive alterations in their arthropod hosts. Widely discordant host and Wolbachia phylogenies indicate that horizontal transmission of these bacteria among species sometimes occurs. A likely means of horizontal transfer is through the feeding relations of organisms within communities. Feeding interactions among insects within the rice-field insect community have been well documented in the past. Here, we present the results of a polymerase chain reaction-based survey and phylogenetic analysis of Wolbachia strains in the rice-field insect community of Thailand. Our field survey indicated that 49 of 209 (23.4%) rice-field insect species were infected with Wolbachia. Of the 49 infected species, 27 were members of two feeding complexes: (i) a group of 13 hoppers preyed on by 2 mirid species and parasitized by a fly species, and (ii) 2 lepidopteran pests parasitized by 9 wasp species. Wolbachia strains found in three hoppers, Recilia dorsalis, Nephotettix malayanus and Nisia nervosa, the two mirid predators, Cyrtorhinus lividipennis and Tytthus chinensis, and the fly parasitoid, Tomosvaryella subvirescens, were all in the same Wolbachia clade. In the second complex, the two lepidopteran pests, Cnaphalocrocis medinalis and Scirpophaga incertulas, were both infected with Wolbachia from the same clade, as was the parasitoid Tropobracon schoenobii. However, none of the other infected parasitoid species in this feeding complex was infected by Wolbachia from this clade. Mean (+/- SD) genetic distance of Wolbachia wsp sequences among interacting species pairs of the hopper feeding complex (0.118 +/- 0.091 nucleotide sequence differences), but not for the other two complexes, was significantly smaller than that between noninteracting species pairs (0.162 +/- 0.079 nucleotide sequence differences). Our results suggest that some feeding complexes, such as the hopper complex described here, could be an important

  13. Distribution, genetic diversity and potential spatiotemporal scale of alien gene flow in crop wild relatives of rice (Oryza spp.) in Colombia.

    Science.gov (United States)

    Thomas, Evert; Tovar, Eduardo; Villafañe, Carolina; Bocanegra, José Leonardo; Moreno, Rodrigo

    2017-12-01

    Crop wild relatives (CWRs) of rice hold important traits that can contribute to enhancing the ability of cultivated rice (Oryza sativa and O. glaberrima) to produce higher yields, cope with the effects of climate change, and resist attacks of pests and diseases, among others. However, the genetic resources of these species remain dramatically understudied, putting at risk their future availability from in situ and ex situ sources. Here we assess the distribution of genetic diversity of the four rice CWRs known to occur in Colombia (O. glumaepatula, O. alta, O. grandiglumis, and O. latifolia). Furthermore, we estimated the degree of overlap between areas with suitable habitat for cultivated and wild rice, both under current and predicted future climate conditions to assess the potential spatiotemporal scale of potential gene flow from GM rice to its CWRs. Our findings suggest that part of the observed genetic diversity and structure, at least of the most exhaustively sampled species, may be explained by their glacial and post-glacial range dynamics. Furthermore, in assessing the expected impact of climate change and the potential spatiotemporal scale of gene flow between populations of CWRs and GM rice we find significant overlap between present and future suitable areas for cultivated rice and its four CWRs. Climate change is expected to have relatively limited negative effects on the rice CWRs, with three species showing opportunities to expand their distribution ranges in the future. Given (i) the sparse presence of CWR populations in protected areas (ii) the strong suitability overlap between cultivated rice and its four CWRs; and (iii) the complexity of managing and regulating areas to prevent alien gene flow, the first priority should be to establish representative ex situ collections for all CWR species, which currently do not exist. In the absence of studies under field conditions on the scale and extent of gene flow between cultivated rice and its Colombian

  14. Analysis of rice purchase decision on rice consumer in Bandung city

    Science.gov (United States)

    Kusno, K.; Imannurdin, A.; Syamsiyah, N.; Djuwendah, E.

    2018-03-01

    This study was conducted at three kinds of purchase location which were traditional market, rice kiosk, and supermarket in Bandung City, with survey data of 108 respondents which were selected by systematic random sampling. The aim of this study is to (1) identify consumer characteristics, (2) identify which atribute is considered by consumer in buying rice, and (3) analyze the relationship between purchase decision and income class. Data were analyzed by descriptive analysis and Chi Square test. The results showed most consumers in the traditional market were middle-educated and lower middle-income, at the rice kiosk, the consumer were generally middle-educated and middle-income, and in the supermarkets, the majority were high-educated and upper middle-income consumers. “Kepulenan” be the first priority of most consumers, but for the lower-middle class, the main priority was price. Thus, in case of scarcity and rice price increase, the government should immediately arrange market operations which targeting to lower-middle class consumers. There was a significant relationship between (1) the quality of rice consumed, (2) the frequency of rice purchase per month, and (3) attitudes toward rice price increase; each with the income class. Although the price of rice increase, consumers of middle and upper-middle were remain loyal to the quality of rice they consumed. This indicates rice market in Bandung city is an ideal market for premium rice so that traders and producers are expected to maintain the quality of rice, such as keep using superior seeds and applying good cultivation based on Good Agricultural Practice (GAP) rules.

  15. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  16. Spatial Field Variability Mapping of Rice Crop using Clustering Technique from Space Borne Hyperspectral Data

    Science.gov (United States)

    Moharana, S.; Dutta, S.

    2015-12-01

    Precision farming refers to field-specific management of an agricultural crop at a spatial scale with an aim to get the highest achievable yield and to achieve this spatial information on field variability is essential. The difficulty in mapping of spatial variability occurring within an agriculture field can be revealed by employing spectral techniques in hyperspectral imagery rather than multispectral imagery. However an advanced algorithm needs to be developed to fully make use of the rich information content in hyperspectral data. In the present study, potential of hyperspectral data acquired from space platform was examined to map the field variation of paddy crop and its species discrimination. This high dimensional data comprising 242 spectral narrow bands with 30m ground resolution Hyperion L1R product acquired for Assam, India (30th Sept and 3rd Oct, 2014) were allowed for necessary pre-processing steps followed by geometric correction using Hyperion L1GST product. Finally an atmospherically corrected and spatially deduced image consisting of 112 band was obtained. By employing an advanced clustering algorithm, 12 different clusters of spectral waveforms of the crop were generated from six paddy fields for each images. The findings showed that, some clusters were well discriminated representing specific rice genotypes and some clusters were mixed treating as a single rice genotype. As vegetation index (VI) is the best indicator of vegetation mapping, three ratio based VI maps were also generated and unsupervised classification was performed for it. The so obtained 12 clusters of paddy crop were mapped spatially to the derived VI maps. From these findings, the existence of heterogeneity was clearly captured in one of the 6 rice plots (rice plot no. 1) while heterogeneity was observed in rest of the 5 rice plots. The degree of heterogeneous was found more in rice plot no.6 as compared to other plots. Subsequently, spatial variability of paddy field was

  17. A maize resistance gene functions against bacterial streak disease in rice.

    Science.gov (United States)

    Zhao, Bingyu; Lin, Xinghua; Poland, Jesse; Trick, Harold; Leach, Jan; Hulbert, Scot

    2005-10-25

    Although cereal crops all belong to the grass family (Poacea), most of their diseases are specific to a particular species. Thus, a given cereal species is typically resistant to diseases of other grasses, and this nonhost resistance is generally stable. To determine the feasibility of transferring nonhost resistance genes (R genes) between distantly related grasses to control specific diseases, we identified a maize R gene that recognizes a rice pathogen, Xanthomonas oryzae pv. oryzicola, which causes bacterial streak disease. Bacterial streak is an important disease of rice in Asia, and no simply inherited sources of resistance have been identified in rice. Although X. o. pv. oryzicola does not cause disease on maize, we identified a maize gene, Rxo1, that conditions a resistance reaction to a diverse collection of pathogen strains. Surprisingly, Rxo1 also controls resistance to the unrelated pathogen Burkholderia andropogonis, which causes bacterial stripe of sorghum and maize. The same gene thus controls resistance reactions to both pathogens and nonpathogens of maize. Rxo1 has a nucleotide-binding site-leucine-rich repeat structure, similar to many previously identified R genes. Most importantly, Rxo1 functions after transfer as a transgene to rice, demonstrating the feasibility of nonhost R gene transfer between cereals and providing a valuable tool for controlling bacterial streak disease.

  18. Carbon-14 dynamics in rice: an extension of the ORYZA2000 model

    Energy Technology Data Exchange (ETDEWEB)

    Galeriu, D.; Melintescu, A. [' ' Horia Hulubei' ' National Institute for Physics and Nuclear Engineering, Life and Environmental Physics Department, 30 Reactorului St., POB MG-6, Bucharest-Magurele (Romania)

    2014-03-15

    Carbon-14 ({sup 14}C) is a radionuclide of major interest in nuclear power production. The Fukushima accident changed the public attitude on the use of nuclear energy all over the world. In terms of nuclear safety, the need of quality-assured radiological models was emphasized by many international organizations, and for models used by decision-makers (i.e. regulatory environmental models and radiological models), a moderate conservatism, transparency, relative simplicity and user friendliness are required. Because the interaction between crops and the environment is complex and regulated by many feedback mechanisms, however, these requirements are difficult to accomplish. The present study makes a step forward regarding the development of a robust model dealing with food contamination after a short-term accidental emission and considers a single crop species, rice (Oryza sativa), one of the most widely used rice species. Old and more recent experimental data regarding the carbon dynamics in rice plants are reviewed, and a well-established crop growth model, ORYZA2000, is used and adapted in order to assess the dynamics of {sup 14}C in rice after a short-term exposure to {sup 14}CO{sub 2}. Here, the model is used to investigate the role of the genotype, management and weather on the concentration of radiocarbon at harvest. (orig.)

  19. Laboratory Screening for Resistance in Rice to Rice Stem Borer Chilo Suppressalis Walker

    International Nuclear Information System (INIS)

    Singgih Sutrisno

    2004-01-01

    Rice stem borer Chilo suppressalis Walker is one of the major insect pests in rice in Indonesia. The use of insect pest resistant variety of rice is one of the effective techniques against pests. Breeding of resistance to insect pests rice crops often faced difficulties in obtaining a lot of insect amounts due to the unavailability of enough number insects pests in the field so that a laboratory bioassay is needed. In this experiments five rice varieties were used: a Pelita I/1, Atomita I, Cisadane, Cisanggarung, and IR 36. Rice seedling 7 days of age were put in 1 liter plastic vials for rice resistance test against the attack of insect pest C. suppressalis. The parameters observed were larval and pupal viability, pupal weight, and eggs production. The larval and pupal viability which were reared on of Pelita I/1 and Atomita I rice seedlings were 68.5 % - 55.5 % and 57.3 % - 46.7 % respectively. The respective lowest percentages were found in IR 36 which was about 41.3 % - 29.8 % .The experiment results on the parameters of pupal weight and egg production showed similar results to that on the parameters of larval and pupal viability. Rice variety of IR 36 showed more resistance to the other varieties, while Pelita I/1 and Atomita I showed the most susceptible to the attack of insect pest C. suppressalis. (author)

  20. Understanding the evolution of rice technology in China - from traditional agriculture to GM rice today.

    Science.gov (United States)

    Shen, Xiaobai

    2010-01-01

    This paper provides an historical survey of the evolution of rice technology in China, from the traditional farming system to genetically modified rice today. Using sociotechnological analytical framework, it analyses rice technology as a socio-technical ensemble - a complex interaction of material and social elements, and discusses the specificity of technology development and its socio-technical outcomes. It points to two imperatives in rice variety development: wholesale transporting agricultural technology and social mechanism to developing countries are likely lead to negative consequences; indigenous innovation including deploying GM technology for seed varietal development and capturing/cultivating local knowledge will provide better solutions.

  1. PhosphoRice: a meta-predictor of rice-specific phosphorylation sites

    Directory of Open Access Journals (Sweden)

    Que Shufu

    2012-02-01

    Full Text Available Abstract Background As a result of the growing body of protein phosphorylation sites data, the number of phosphoprotein databases is constantly increasing, and dozens of tools are available for predicting protein phosphorylation sites to achieve fast automatic results. However, none of the existing tools has been developed to predict protein phosphorylation sites in rice. Results In this paper, the phosphorylation site predictors, NetPhos 2.0, NetPhosK, Kinasephos, Scansite, Disphos and Predphosphos, were integrated to construct meta-predictors of rice-specific phosphorylation sites using several methods, including unweighted voting, unreduced weighted voting, reduced unweighted voting and weighted voting strategies. PhosphoRice, the meta-predictor produced by using weighted voting strategy with parameters selected by restricted grid search and conditional random search, performed the best at predicting phosphorylation sites in rice. Its Matthew's Correlation Coefficient (MCC and Accuracy (ACC reached to 0.474 and 73.8%, respectively. Compared to the best individual element predictor (Disphos_default, PhosphoRice archieved a significant increase in MCC of 0.071 (P Conclusions PhosphoRice is a powerful tool for predicting unidentified phosphorylation sites in rice. Compared to the existing methods, we found that our tool showed greater robustness in ACC and MCC. PhosphoRice is available to the public at http://bioinformatics.fafu.edu.cn/PhosphoRice.

  2. International tourist preference of Lodok Rice Field natural elements, the cultural rice field from Manggarai - Indonesia

    Science.gov (United States)

    March Syahadat, Ray; Trie Putra, Priambudi; Nuraini; Nailufar, Balqis; Fatmala Makhmud, Desy

    2017-10-01

    Lodok Rice Field or usually known as spiderweb rice field is a system of land division. It cultural rice field only found on Manggarai, Province of East Nusa Tenggara, Indonesia. The landscape of Lodok Rice Field was aesthetic and it has big potential for tourism development. The aim of this study was to know the perception of natural elements of Lodok Rice Field landscape that could influence international tourist to visited Lodok Rice Field. If we know the elements that could influenced the international tourist, we could used the landscape image for tourism media promotion. The methods of this study used scenic beauty estimation (SBE) by 85 respondents from 34 countries and Kruskal Wallis H test. The countries grouped by five continents (Asia, America, Europe, Africa, and Oceania). The result showed that the Asian respondents liked the elements of sky, mountain, and the rice field. Then, the other respondent from another continent liked the elements of sunshine, mountain, and the rice field. Although the Asian had different perception about landscape elements of rice field’s good view, it’s not differ significantly by Kruskal Wallis H test.

  3. Creation of transgenic rice plants producing small interfering RNA of Rice tungro spherical virus.

    Science.gov (United States)

    Le, Dung Tien; Chu, Ha Duc; Sasaya, Takahide

    2015-01-01

    Rice tungro spherical virus (RTSV), also known as Rice waika virus, does not cause visible symptoms in infected rice plants. However, the virus plays a critical role in spreading Rice tungro bacilliform virus (RTBV), which is the major cause of severe symptoms of rice tungro disease. Recent studies showed that RNA interference (RNAi) can be used to develop virus-resistance transgenic rice plants. In this report, we presented simple procedures and protocols needed for the creation of transgenic rice plants capable of producing small interfering RNA specific against RTSV sequences. Notably, our study showed that 60 out of 64 individual hygromycin-resistant lines (putative transgenic lines) obtained through transformation carried transgenes designed for producing hairpin double-stranded RNA. Northern blot analyses revealed the presence of small interfering RNA of 21- to 24-mer in 46 out of 56 confirmed transgenic lines. Taken together, our study indicated that transgenic rice plants carrying an inverted repeat of 500-bp fragments encoding various proteins of RTSV can produce small interfering RNA from the hairpin RNA transcribed from that transgene. In light of recent studies with other viruses, it is possible that some of these transgenic rice lines might be resistant to RTSV.

  4. Lead in rice: analysis of baseline lead levels in market and field collected rice grains.

    Science.gov (United States)

    Norton, Gareth J; Williams, Paul N; Adomako, Eureka E; Price, Adam H; Zhu, Yongguan; Zhao, Fang-Jie; McGrath, Steve; Deacon, Claire M; Villada, Antia; Sommella, Alessia; Lu, Ying; Ming, Lei; De Silva, P Mangala C S; Brammer, Hugh; Dasgupta, Tapash; Islam, M Rafiqul; Meharg, Andrew A

    2014-07-01

    In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 μg g(-1) lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Characterization of Volatile Flavor Compounds in Chinese Rice Wine Fermented from Enzymatic Extruded Rice.

    Science.gov (United States)

    Xu, Enbo; Long, Jie; Wu, Zhengzong; Li, Hongyan; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

    2015-07-01

    Enzymatic extrusion, instead of traditional steam cooking, to treat rice is an efficient and alternative pretreatment for Chinese rice wine fermentation. In order to determine the formation of volatiles in enzymatic extrusion-processed rice wine (EE), and to confirm its characteristic flavor compounds, headspace solid-phase micro-extraction followed by GC-MS was used. A total of 66 volatile compounds were identified in EE. During fermentation, most volatiles generated from enzymatic extruded rice had the similar trends with those from steam-cooked rice, but the differences in the concentration of volatiles indicated a changed balance of flavors release caused by enzymatic extrusion. Besides, the concentrations and sorts of volatiles in EEs fermented from different rice particle sizes, were not dramatically different. By principal component analysis, EE could be distinctly separated from other traditional Chinese rice wines according to its characteristic volatiles, namely, 2-heptanol, 1-octen-3-ol, ethyl 4-hydroxybenzoate, methylpentyl 2-propenoate, γ-hexalactone, and 4-vinylguaiacol. Enzymatic extrusion liquefaction has been a popular thermal treatment for cereals, and gradually being applied in fermentation and liquor-making industry all over the world. The characterization of volatile flavor compounds in Chinese rice wine processed by enzymatic extrusion liquefaction pretreatment, might be made use not only for a better understanding of this new-type rice wine, but for the further utilization of enzymatic extrusion in other wine or alcohol production as well. © 2015 Institute of Food Technologists®

  6. An update on the use of co-products from the milling of rice in value added food products

    Science.gov (United States)

    Because of the huge quantity of rice produced annually, milled-rice co-products; such as, rice bran, rice oil, rice wax, rice flour, and rice hull are plentiful and readily available. These co-products could be valuable sources of food ingredients, but they have been vastly under-utilized. Rice bra...

  7. Interactions among spectral components of radiation in the growth responses of rice, tomato and strawberry

    International Nuclear Information System (INIS)

    Inada, K.; Matsuno, A.

    1985-01-01

    Effects of spectral components and their ratios of radiation on simultaneous growth responses were investigated with rice, tomato and strawberry plants exposed to lights with a high fluence rate (350 or 408 μmol m -2 s -1 , 400-700 nm) during every daytime. Both elongation growth and Ieaf area development in rice and strawberry were promoted by red (R) but inhibited by blue (B) component depending on the each fluence rate. However, leaf area in tomato responded in opposite direction to these. The elongation growth was remarkably increased with the fluence rate of far-red (FR) in tomato and strawberry, but not in rice. These responses were lineary increased, except FR and UV effects, with logarithmic R/B ratio in rice and strawberry but not in tomato. A very low R/FR ratio caused a strong promotion of both elongation and leaf area in tomato, while it promoted petiole elengation but inhibited leaf area development in strawberry. The elongation and leaf area development responded to R/FR in reverse way between rice and strawberry. Chlorophyll content of leaves was generally decreased with the increase of logarithmic R/B ratio in all the species. Areal weight of leaf and dry weight increment/leaf area were more or less increased with R/B and R/ FR ratios, Dry weight increment varied with the spectral ratios in almost the same way as leaf area, suggesting that spectral dependence of photosynthetic production was not much different between the species. Some discussions were made on the photoreceptor pigments involved in the elongation growth and leaf area development, and on the selection of light quantity to ensure a normal growth of each plant species

  8. Prokaryote community dynamics in anaerobic co-digestion of swine manure, rice straw and industrial clay residuals.

    Science.gov (United States)

    Jiménez, Janet; Theuerl, Susanne; Bergmann, Ingo; Klocke, Michael; Guerra, Gilda; Romero-Romero, Osvaldo

    The aim of this study was to analyze the effect of the addition of rice straw and clay residuals on the prokaryote methane-producing community structure in a semi-continuously stirred tank reactor fed with swine manure. Molecular techniques, including terminal restriction fragment length polymorphism and a comparative nucleotide sequence analyses of the prokaryotic 16S rRNA genes, were performed. The results showed a positive effect of clay addition on methane yield during the co-digestion of swine manure and rice straw. At the digestion of swine manure, the bacterial phylum Firmicutes and the archaeal family Methanosarcinaceae, particularly Methanosarcina species, were predominant. During the co-digestion of swine manure and rice straw the microbial community changed, and with the addition of clay residual, the phylum Bacteroidetes predominated. The new nutritional conditions resulted in a shift in the archaeal family Methanosarcinaceae community as acetoclastic Methanosaeta species became dominant.

  9. Evidence for biotrophic lifestyle and biocontrol potential of dark septate endophyte Harpophora oryzae to rice blast disease.

    Directory of Open Access Journals (Sweden)

    Zhen-Zhu Su

    Full Text Available The mutualism pattern of the dark septate endophyte (DSE Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the elongation zone, and heavy colonization in the differentiation zone. H. oryzae adopted a biotrophic lifestyle in roots accompanied by programmed cell death. Real-time PCR facilitated the accurate quantification of fungal growth and the respective plant response. The biocontrol potential of H. oryzae was visualized by inoculation with eGFP-tagged M. oryzae in rice. H. oryzae protected rice from M. oryzae root invasion by the accumulation of H2O2 and elevated antioxidative capacity. H. oryzae also induced systemic resistance against rice blast. This systemic resistance was mediated by the OsWRKY45-dependent salicylic acid (SA signaling pathway, as indicated by the strongly upregulated expression of OsWRKY45. The colonization pattern of H. oryzae was consistent with the typical characteristics of DSEs. H. oryzae enhanced local resistance by reactive oxygen species (ROS and high antioxidative level and induced OsWRKY45-dependent SA-mediated systemic resistance against rice blast.

  10. The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Thomas, Nicholas C; Oksenberg, Nir; Liu, Furong; Caddell, Daniel; Nalyvayko, Alina; Nguyen, Yen; Schwessinger, Benjamin; Ronald, Pamela C

    2018-01-01

    Rice ( Oryza sativa ) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo . To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo . We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo . These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo .

  11. Mapping paddy rice planting area in rice-wetland coexistent areas through analysis of Landsat 8 OLI and MODIS images.

    Science.gov (United States)

    Zhou, Yuting; Xiao, Xiangming; Qin, Yuanwei; Dong, Jinwei; Zhang, Geli; Kou, Weili; Jin, Cui; Wang, Jie; Li, Xiangping

    2016-04-01

    Accurate and up-to-date information on the spatial distribution of paddy rice fields is necessary for the studies of trace gas emissions, water source management, and food security. The phenology-based paddy rice mapping algorithm, which identifies the unique flooding stage of paddy rice, has been widely used. However, identification and mapping of paddy rice in rice-wetland coexistent areas is still a challenging task. In this study, we found that the flooding/transplanting periods of paddy rice and natural wetlands were different. The natural wetlands flood earlier and have a shorter duration than paddy rice in the Panjin Plain, a temperate region in China. We used this asynchronous flooding stage to extract the paddy rice planting area from the rice-wetland coexistent area. MODIS Land Surface Temperature (LST) data was used to derive the temperature-defined plant growing season. Landsat 8 OLI imagery was used to detect the flooding signal and then paddy rice was extracted using the difference in flooding stages between paddy rice and natural wetlands. The resultant paddy rice map was evaluated with in-situ ground-truth data and Google Earth images. The estimated overall accuracy and Kappa coefficient were 95% and 0.90, respectively. The spatial pattern of OLI-derived paddy rice map agrees well with the paddy rice layer from the National Land Cover Dataset from 2010 (NLCD-2010). The differences between Rice Landsat and Rice NLCD are in the range of ±20% for most 1-km grid cell. The results of this study demonstrate the potential of the phenology-based paddy rice mapping algorithm, via integrating MODIS and Landsat 8 OLI images, to map paddy rice fields in complex landscapes of paddy rice and natural wetland in the temperate region.

  12. Genomic selection and association mapping in rice (Oryza sativa): effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Science.gov (United States)

    Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R

    2015-02-01

    Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  13. Genomic selection and association mapping in rice (Oryza sativa: effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Directory of Open Access Journals (Sweden)

    Jennifer Spindel

    2015-02-01

    Full Text Available Genomic Selection (GS is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  14. Genomic Selection and Association Mapping in Rice (Oryza sativa): Effect of Trait Genetic Architecture, Training Population Composition, Marker Number and Statistical Model on Accuracy of Rice Genomic Selection in Elite, Tropical Rice Breeding Lines

    Science.gov (United States)

    Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R.

    2015-01-01

    Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline. PMID:25689273

  15. Rice saabus Euroopat taltsutama / Tõnu Prei

    Index Scriptorium Estoniae

    Prei, Tõnu, 1950-

    2005-01-01

    USA välisminister Condolezza Rice alustas ringreisi Euroopas, eesmärgiks anda vastulöök USA-d tabanud kriitikale sõjavangide kohtlemise ja teistes riikides oma luuretalituse salavanglate pidamise pärast

  16. USING RICE BRAN IN LAYING HEN DIETS

    Directory of Open Access Journals (Sweden)

    H ERSIN SAMLI

    2006-10-01

    Full Text Available Rice bran is an energy and protein rich ingredient used in poultry feeding. To balance energy and protein requirements. The purpose of this study is to examine the effects of rice bran on performance and egg quality during peak production of a commercial White laying strain of 22 week of age. Dietary treatments were consisted by inclusion of rice bran at 0, 5, 10 and 15% levels. Each treatment had 6 reps in which 12 birds were randomly assigned in wired fl oor battery cages equipped with nipple drinkers and through feeders. Layers accessed to feed and water freely. Lighting regimen was adjusted to 16h light/8h dark. The experiment lasted for 10 weeks. Overall results of the present experiment indicated that rice bran could be included up to 10% without any adverse affect on laying performance, egg quality and digestive organs.

  17. Reconciling the conservation of the purple swamphen (Porphyrio porphyrio and its damage in Mediterranean rice fields through sustainable non-lethal techniques

    Directory of Open Access Journals (Sweden)

    Rubén Moreno-Opo

    2018-04-01

    Full Text Available Resolving human–wildlife conflicts requires the assessment and implementation of appropriate technical measures that minimize negative impacts on socio-economic uses, including agriculture, and ensure the adequate protection of biological diversity. Rice paddies are widely distributed in the western Mediterranean region. Because of their high productivity, they can be a good habitat for waterbirds, including the purple swamphen Porphyrio porphyrio, particularly in areas where natural wetlands have been removed or reduced. As a result of its population growth, there have been increasing levels of damage caused by this species in rice fields due to stem-cutting and opening of bald patches in rice fields. With the aim of reducing damage, we evaluated the effectiveness of passive and active measures that would limit access to rice fields and deter/scare away purple swamphens in affected areas of the Ebro Delta (NE Spain. We selected the techniques according to the growth phase of rice and the activity of birds in the rice fields (perimeter fences and clearing vegetation around the rice plots during sprouting and growing phases, and falconry at maturation. There were positive results during the sprouting and growing phases thanks to fences and clearing vegetation, reducing the affected area by 37.8% between treatment and control plots. This would mean an economic savings of 18,550 €/year in compensation payments by regional administrations including the investment in implementing and maintaining passive protection measures. Active deterrence through falconry did not reduce the level of damage. The analysis of purple swamphen home range, activity centers (centroids, and the proportion of locations in and outside of rice fields showed no differences before and after dissuasive practices. These results were influenced by multiple concurrent factors including weather, the structural configuration of the rice plots and their location. In summary, we

  18. The Potency of White Rice (Oryza sativa), Black Rice (Oryza sativa L. indica), and Red Rice (Oryza nivara) as Antioxidant and Tyrosinase Inhibitor

    Science.gov (United States)

    Batubara, I.; Maharni, M.; Sadiah, S.

    2017-04-01

    Rice is known to have many beneficial biological activities and is often used as “bedak dingin”, a face powder. The content of vitamins, minerals, fiber, and several types of antioxidants, such as ferulic acid, phytic acid, tocopherol, and oryzanols [1-2] are predicted to be potential as a tyrosinase inhibitor. The purpose of this study is to determine the potency of extracts from there types of rice, namely white, red, and black rice as an antioxidant and tyrosinase inhibitor. The rice was extracted with three different solvents, n-hexane, ethyl acetate, and methanol. The results showed that the highest antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl method was found in the methanol extract of black rice (IC50 290 μg/mL). Meanwhile, ethyl acetate extract of white rice has the highest antioxidant activity withphosphomolybdic acid method (41 mmol α-tocopherol equivalents/g sample). Thus, methanol extract of black rice and ethyl acetate extract of white rice are potential as an antioxidant. For tyrosinase inhibitor, n-hexane extract of red rice (IC50 3156 μg/mL) was the most active extract. The active component for radical scavenging is polar compound and for antioxidant by phosphomolybdate method is less polar compounds in black rice methanol extract based on TLC bioautogram. In conclusion, the black rice is the most potent in antioxidant while red rice is for tyrosinase inhibition.

  19. Reconstruction of putative DNA virus from endogenous rice tungro bacilliform virus-like sequences in the rice genome: implications for integration and evolution

    Directory of Open Access Journals (Sweden)

    Kishima Yuji

    2004-10-01

    Full Text Available Abstract Background Plant genomes contain various kinds of repetitive sequences such as transposable elements, microsatellites, tandem repeats and virus-like sequences. Most of them, with the exception of virus-like sequences, do not allow us to trace their origins nor to follow the process of their integration into the host genome. Recent discoveries of virus-like sequences in plant genomes led us to set the objective of elucidating the origin of the repetitive sequences. Endogenous rice tungro bacilliform virus (RTBV-like sequences (ERTBVs have been found throughout the rice genome. Here, we reconstructed putative virus structures from RTBV-like sequences in the rice genome and characterized to understand evolutionary implication, integration manner and involvements of endogenous virus segments in the corresponding disease response. Results We have collected ERTBVs from the rice genomes. They contain rearranged structures and no intact ORFs. The identified ERTBV segments were shown to be phylogenetically divided into three clusters. For each phylogenetic cluster, we were able to make a consensus alignment for a circular virus-like structure carrying two complete ORFs. Comparisons of DNA and amino acid sequences suggested the closely relationship between ERTBV and RTBV. The Oryza AA-genome species vary in the ERTBV copy number. The species carrying low-copy-number of ERTBV segments have been reported to be extremely susceptible to RTBV. The DNA methylation state of the ERTBV sequences was correlated with their copy number in the genome. Conclusions These ERTBV segments are unlikely to have functional potential as a virus. However, these sequences facilitate to establish putative virus that provided information underlying virus integration and evolutionary relationship with existing virus. Comparison of ERTBV among the Oryza AA-genome species allowed us to speculate a possible role of endogenous virus segments against its related disease.

  20. [Effects of rice cleaning and cooking process on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice].

    Science.gov (United States)

    Satoh, Motoaki; Sakaguchi, Masayuki; Kobata, Masakazu; Sakaguchi, Yoko; Tanizawa, Haruna; Miura, Yuri; Sasano, Ryoichi; Nakanishi, Yutaka

    2003-02-01

    We studied the effect of cleaning and cooking on the residues of flutolanil, fenobucarb, silafluofen and buprofezin in rice. The rice had been sprayed in a paddy field in Wakayama city, with 3 kinds of pesticide application protocols: spraying once at the usual concentration of pesticides, repeated spraying (3 times) with the usual concentration of pesticides and spraying once with 3 times the usual concentration of pesticides. The residue levels of pesticide decreased during the rice cleaning process. Silafluofen, which has a higher log Pow value, remained in the hull of the rice. Fenobucarb, which has a lower log Pow value, penetrated inside the rice. The residue concentration of pesticide in polished rice was higher than that in pre-washed rice processed ready for cooking. During the cooking procedure, the reduction of pesticides in polished rice was higher than that in brown rice.

  1. A review of microsatellite markers and their applications in rice breeding programs to improve blast disease resistance.

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Islam, Kh Nurul; Latif, Mohammad Abdul

    2013-11-14

    Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR), and they are typically composed of 1-6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS) can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS in rice breeding

  2. A Review of Microsatellite Markers and Their Applications in Rice Breeding Programs to Improve Blast Disease Resistance

    Directory of Open Access Journals (Sweden)

    Mohammad Abdul Latif

    2013-11-01

    Full Text Available Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR, and they are typically composed of 1–6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS

  3. Biophysical and Mechanical properties of rice varieties: attributes to ...

    African Journals Online (AJOL)

    It requires about 25N for the rice grain (IITA306) to fail at 0.7mm at horizontal and 150N to crack the rice grain in vertical position at 21.0mm, it takes 60N for the rice grain (MAS) to fail at 1.4mm and 150N to crack the rice grain at 22.5mm as well as 58N for the rice grain (R18) to fail at 1.2mm and 125N to crack the rice grain ...

  4. Effect of gamma irradiation on rice and its food products

    International Nuclear Information System (INIS)

    Sung, W.-C.

    2005-01-01

    Two milled indica rice varieties were exposed to gamma radiation with doses ranging from 0 to 1.0 kGy. The effects of gamma irradiation on rice flour pasting properties and the qualities of its food product, rice curd, were compared to the effects of storage. A dose of 1 kGy can decrease the flour paste viscosity and tenderize the texture of the rice curd to similar levels as those obtained after 12 months of storage. It was thus shown that gamma irradiation could shorten the indica rice aging time and improve the processing stability and quality of rice products

  5. Effect of gamma irradiation on rice and its food products

    Energy Technology Data Exchange (ETDEWEB)

    Sung, W.-C. [Department of Hotel and Restaurant Management, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Sec. 1, Pao-An, Jen-Te Hsiang, Tainan 717, Taiwan (China)]. E-mail: sungwilliam2001@yahoo.com.tw

    2005-07-01

    Two milled indica rice varieties were exposed to gamma radiation with doses ranging from 0 to 1.0 kGy. The effects of gamma irradiation on rice flour pasting properties and the qualities of its food product, rice curd, were compared to the effects of storage. A dose of 1 kGy can decrease the flour paste viscosity and tenderize the texture of the rice curd to similar levels as those obtained after 12 months of storage. It was thus shown that gamma irradiation could shorten the indica rice aging time and improve the processing stability and quality of rice products.

  6. An update on the use of rice in value-added food products.

    Science.gov (United States)

    Because of the huge quantity of rice produced annually, milled-rice co-products; such as, rice flour, rice bran, rice wax, and rice hull are plentiful and readily available. These co-products could be valuable sources of food ingredients, but they have been vastly under-utilized. This is a report ...

  7. Comparative "Omics" of the Fusarium fujikuroi Species Complex Highlights Differences in Genetic Potential and Metabolite Synthesis

    NARCIS (Netherlands)

    Niehaus, E.-M.; Münsterkötter, M.; Proctor, R.H.; Brown, D.W.; Sharon, A.; Idan, Y.; Oren-Young, L.; Sieber, C.M.; Novák, O.; Pěnčík, A.; Tarkowská, D.; Hromadová, K.; Freeman, S.; Maymon, M.; Elazar, M.; Youssef, S.A.; El-Shabrawy, E.S.M.; Shalaby, A.B.A.; Houterman, P.; Brock, N.L.; Burkhardt, I.; Tsavkelova, E.A.; Dickschat, J.S.; Galuszka, P.; Güldener, U.; Tudzynski, B.

    2016-01-01

    Species of the Fusarium fujikuroi species complex (FFC) cause a wide spectrum of often devastating diseases on diverse agricultural crops, including coffee, fig, mango, maize, rice, and sugarcane. Although species within the FFC are difficult to distinguish by morphology, and their genes often share

  8. Volatile constituents of the essential oils of two Polygonum species from Vietnam

    NARCIS (Netherlands)

    Dung, N.X.; Van, le H.; Moi, La Dinh; Cu, Lu'u Dam; Leclercq, P.A.

    1994-01-01

    Polygonum species grown in many places in Vietnam, esp. on the rice-field. It is used in the traditional medicine. After Pham Hoang Ho until now in Vietnam, 40 Polygonum species have been found. From the polygonum genus (Family Polygonaceae) the essential oils of 2 species are reported: Polygonum

  9. Genetic diversity in Oryza glumaepatula wild rice populations in Costa Rica and possible gene flow from O. sativa.

    Science.gov (United States)

    Fuchs, Eric J; Meneses Martínez, Allan; Calvo, Amanda; Muñoz, Melania; Arrieta-Espinoza, Griselda

    2016-01-01

    Wild crop relatives are an important source of genetic diversity for crop improvement. Diversity estimates are generally lacking for many wild crop relatives. The objective of the present study was to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated the likelihood of gene flow between wild and commercial rice species because the latter is commonly sympatric with wild rice populations. Introgression may change wild species by incorporating alleles from domesticated species, increasing the risk of losing original variation. Specimens from all known O. glumaepatula populations in Costa Rica were analyzed with 444 AFLP markers to characterize genetic diversity and structure. We also compared genetic diversity estimates between O. glumaepatula specimens and O. sativa commercial rice. Our results showed that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. Despite the restricted distribution of this species in Costa Rica, populations are fairly large, reducing the effects of drift on genetic diversity. We found a dismissible but significant structure (θ = 0.02 ± 0.001) among populations. A Bayesian structure analysis suggested that some individuals share a significant proportion of their genomes with O. sativa. These results suggest that gene flow from cultivated O. sativa populations may have occurred in the recent past. These results expose an important biohazard: recurrent hybridization may reduce the genetic diversity of this wild rice species. Introgression may transfer commercial traits into O. glumaepatula, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.

  10. Rice is the seed of the monocot plants Oryza sativa (Asian rice) or ...

    African Journals Online (AJOL)

    BIOTECH

    2013-10-16

    Oct 16, 2013 ... of culture. The regenerated plantlets were transferred to pots for acclimatization. About 80% of plants were survived in the greenhouse condition. Key words: Somatic embryogenesis, immature zygotic embryos, Indica rice, plant regeneration. INTRODUCTION. Rice (Oryza sativa L.) is one of the most ...

  11. Genomic dissection of small RNAs in wild rice (Oryza rufipogon): lessons for rice domestication.

    Science.gov (United States)

    Wang, Yu; Bai, Xuefei; Yan, Chenghai; Gui, Yiejie; Wei, Xinghua; Zhu, Qian-Hao; Guo, Longbiao; Fan, Longjiang

    2012-11-01

    The lack of a MIRNA set and genome sequence of wild rice (Oryza rufipogon) has prevented us from determining the role of MIRNA genes in rice domestication. In this study, a genome, three small RNA populations and a degradome of O. rufipogon were sequenced by Illumina platform and the expression levels of microRNAs (miRNAs) were investigated by miRNA chips. A de novo O. rufipogon genome was assembled using c. 55× coverage of raw sequencing data and a total of 387 MIRNAs were identified in the O. rufipogon genome based on c. 5.2 million unique small RNA reads from three different tissues of O. rufipogon. Of these, O. rufipogon MIRNAs, 259 were not found in the cultivated rice, suggesting a loss of these MIRNAs in the cultivated rice. We also found that 48 MIRNAs were novel in the cultivated rice, suggesting that they were potential targets of domestication selection. Some miRNAs showed significant expression differences between wild and cultivated rice, suggesting that expression of miRNA could also be a target of domestication, as demonstrated for the miR164 family. Our results illustrated that MIRNA genes, like protein-coding genes, might have been significantly shaped during rice domestication and could be one of the driving forces that contributed to rice domestication. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  12. Development and characterization of emulsions containing purple rice bran and brown rice oils

    Science.gov (United States)

    The aims of this study were to characterize purple rice bran oil (PRBO) as extracted from the bran, and to produce and characterize a nano-emulsion containing purple rice bran oil. An emulsion was prepared using PRBO (10%), sodium caseinate (5%) and water (85%). The mixture was sonicated followed ...

  13. Do rice water weevils and rice stem borers compete when sharing a host plant?

    Science.gov (United States)

    Shi, Sheng-Wei; He, Yan; Ji, Xiang-Hua; Jiang, Ming-Xing; Cheng, Jia-An

    2008-07-01

    The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) is an invasive insect pest of rice Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 2~4 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated negatively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.

  14. Do rice water weevils and rice stem borers compete when sharing a host plant?*

    Science.gov (United States)

    Shi, Sheng-wei; He, Yan; Ji, Xiang-hua; Jiang, Ming-xing; Cheng, Jia-an

    2008-01-01

    The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) is an invasive insect pest of rice Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 2~4 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated negatively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice. PMID:18600788

  15. Simultaneous rough rice drying and rice bran stabilization using infrared radiation heating

    Science.gov (United States)

    The objective of this study was to develop a new rice drying method by using IR heating followed by tempering. Freshly harvested medium grain rice (M206) samples with different initial moisture contents (IMCs) were used in this study. The samples were dried for one- and two-passes by using a catalyt...

  16. Rice-eating quality among consumers in different rice grain preference countries

    NARCIS (Netherlands)

    Suwannaporn, P.; Linnemann, A.R.

    2008-01-01

    More rice is eaten nowadays in traditionally nonrice-eating countries. This study investigated consumer eating quality preferences among consumers in target rice export countries to identify opportunities and strategic implications. A quantitative study with 1,128 consumers of target nationalities

  17. Evidence for the Emergence of New Rice Types of Interspecific Hybrid Origin in West African Farmers' Fields

    NARCIS (Netherlands)

    Nuijten, H.A.C.P.; Treuren, van R.; Struik, P.C.; Mokuwa, G.A.; Okry, F.; Teeken, B.W.E.; Richards, P.

    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

  18. Tiling microarray analysis of rice chromosome 10 to identify the transcriptome and relate its expression to chromosomal architecture

    DEFF Research Database (Denmark)

    Li, Lei; Wang, Xiangfeng; Xia, Mian

    2005-01-01

    BACKGROUND: Sequencing and annotation of the genome of rice (Oryza sativa) have generated gene models in numbers that top all other fully sequenced species, with many lacking recognizable sequence homology to known genes. Experimental evaluation of these gene models and identification of new mode...

  19. Electricity generation from rice husk in Indian rice mills: potential and financial viability

    International Nuclear Information System (INIS)

    Kapur, T.; Kandpal, T.C.; Garg, H.P.

    1998-01-01

    Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in the rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (35 Rs approximates to SUS 1.). (author)

  20. Electricity generation from rice husk in Indian rice mills: potential and financial viability

    Energy Technology Data Exchange (ETDEWEB)

    Kapur, T.; Kandpal, T.C.; Garg, H.P. [Indian Inst. of Technology, Centre for Energy Studies, New Delhi (India)

    1998-12-31

    Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in the rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (35 Rs approximates to SUS 1.). (author)

  1. Evidence for Non-Transmission of Rice Yellow Mottle Virus (RYMV through Rice Seed

    Directory of Open Access Journals (Sweden)

    Sy, AA.

    2004-01-01

    Full Text Available An indexing of the organs (radicle and plumule and components (husk, endosperm and embryo of rice seeds using Enzyme Linked Immunosorbent Assay (ELISA was carried out to detect Rice yellow mottle virus (RYMV and establish the exact location of the virus in the rice seed. RYMV was detected only in the husk (seed coat but not in the endosperm, plumule, radicle, nor embryo. None of the seedlings raised from the seeds expressed RYMV symptoms. No virus particle was detected by the ELISA test in the leaves of the screenhouse-reared plants obtained from seeds of infected plants. The results indicate that RYMV is apparently not transmitted through rice seed probably because the virus is seed-borne in the husk (seed coat of mature rice seeds.

  2. Effect of Temperature on Chinese Rice Wine Brewing with High Concentration Presteamed Whole Sticky Rice

    Directory of Open Access Journals (Sweden)

    Dengfeng Liu

    2014-01-01

    Full Text Available Production of high quality Chinese rice wine largely depends on fermentation temperature. However, there is no report on the ethanol, sugars, and acids kinetics in the fermentation mash of Chinese rice wine treated at various temperatures. The effects of fermentation temperatures on Chinese rice wine quality were investigated. The compositions and concentrations of ethanol, sugars, glycerol, and organic acids in the mash of Chinese rice wine samples were determined by HPLC method. The highest ethanol concentration and the highest glycerol concentration both were attained at the fermentation mash treated at 23°C. The highest peak value of maltose (90 g/L was obtained at 18°C. Lactic acid and acetic acid both achieved maximum values at 33°C. The experimental results indicated that temperature contributed significantly to the ethanol production, acid flavor contents, and sugar contents in the fermentation broth of the Chinese rice wines.

  3. Effect of Temperature on Chinese Rice Wine Brewing with High Concentration Presteamed Whole Sticky Rice

    Science.gov (United States)

    Zhang, Hong-Tao; Xiong, Weili; Hu, Jianhua; Xu, Baoguo; Lin, Chi-Chung; Xu, Ling; Jiang, Lihua

    2014-01-01

    Production of high quality Chinese rice wine largely depends on fermentation temperature. However, there is no report on the ethanol, sugars, and acids kinetics in the fermentation mash of Chinese rice wine treated at various temperatures. The effects of fermentation temperatures on Chinese rice wine quality were investigated. The compositions and concentrations of ethanol, sugars, glycerol, and organic acids in the mash of Chinese rice wine samples were determined by HPLC method. The highest ethanol concentration and the highest glycerol concentration both were attained at the fermentation mash treated at 23°C. The highest peak value of maltose (90 g/L) was obtained at 18°C. Lactic acid and acetic acid both achieved maximum values at 33°C. The experimental results indicated that temperature contributed significantly to the ethanol production, acid flavor contents, and sugar contents in the fermentation broth of the Chinese rice wines. PMID:24672788

  4. Diversity and functional traits of culturable microbiome members, including cyanobacteria in the rice phyllosphere.

    Science.gov (United States)

    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. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  5. Development of Ozone Technology Rice Storage Systems (OTRISS) for Quality Improvement of Rice Production

    International Nuclear Information System (INIS)

    Nur, M; Kusdiyantini, E; Wuryanti, W; Winarni, T A; Widyanto, S A; Muharam, H

    2015-01-01

    This research has been carried out by using ozone to address the rapidly declining quality of rice in storage. In the first year, research has focused on the rice storage with ozone technology for small capacity (e.g., household) and the medium capacity (e.g., dormitories, hospitals). Ozone was produced by an ozone generator with Dielectric Barrier Discharge Plasma (DBDP). Ozone technology rice storage system (OTRISS) is using ozone charateristic which is a strong oxidizer. Ozone have a short endurance of existence and then decompose, as a result produce oxygen and radicals of oxygen. These characteristics could kill microorganisms and pests, reduce air humidity and enrich oxygen. All components used in SPBTO assembled using raw materials available in the big cities in Indonesia. Provider of high voltage (High Voltage Power Supply, 40-70 kV, 23 KH, AC) is one of components that have been assembled and tested. Ozone generator is assembled with 7 reactors of Dielectric Barrier Discharge Plasma (DBDP). Rice container that have been prepared for OTRISS have adjusted so can be integrated with generator, power supply and blower to blow air. OTRISS with a capacity of 75 kg and 100 kg have been made and tested. The ability of ozone to eliminate bacteria and fungi have been tested and resulted in a decrease of microorganisms at 3 log CFU/g. Testing in food chemistry showed that ozone treatment of rice had not changed the chemical content that still meet the standard of chemical content and nutritional applicable to ISO standard milled rice. The results of this study are very likely to be used as an alternative to rice storage systems in warehouse. Test and scale-up is being carried out in a mini warehouse whose condition is mimicked to rice in National Rice Storage of Indonesia (Bulog) to ensure quality. Next adaptations would be installed in the rice storage system in the Bulog. (paper)

  6. Integrated rice-duck farming mitigates the global warming potential in rice season.

    Science.gov (United States)

    Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Yu, Xichen; Hang, Yuhao

    2017-01-01

    Integrated rice-duck farming (IRDF), as a mode of ecological agriculture, is an important way to realize sustainable development of agriculture. A 2-year split-plot field experiment was performed to evaluate the effects of IRDF on methane (CH 4 ) and nitrous oxide (N 2 O) emissions and its ecological mechanism in rice season. This experiment was conducted with two rice farming systems (FS) of IRDF and conventional farming (CF) under four paddy-upland rotation systems (PUR): rice-fallow (RF), annual straw incorporating in rice-wheat rotation system (RWS), annual straw-based biogas residues incorporating in rice-wheat rotation system (RWB), and rice-green manure (RGM). During the rice growing seasons, IRDF decreased the CH 4 emission by 8.80-16.68%, while increased the N 2 O emission by 4.23-15.20%, when compared to CF. Given that CH 4 emission contributed to 85.83-96.22% of global warming potential (GWP), the strong reduction in CH 4 emission led to a significantly lower GWP of IRDF as compared to CF. The reason for this trend was because IRDF has significant effect on dissolved oxygen (DO) and soil redox potential (Eh), which were two pivotal factors for CH 4 and N 2 O emissions in this study. The IRDF not only mitigates the GWP, but also increases the rice yield by 0.76-2.43% compared to CF. Moreover, compared to RWS system, RF, RWB and RGM systems significantly reduced CH 4 emission by 50.17%, 44.89% and 39.51%, respectively, while increased N 2 O emission by 10.58%, 14.60% and 23.90%, respectively. And RWS system had the highest GWP. These findings suggest that mitigating GWP and improving rice yield could be simultaneously achieved by the IRDF, and employing suitable PUR would benefit for relieving greenhouse effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. WRKY transcription factor genes in wild rice Oryza nivara.

    Science.gov (United States)

    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. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  8. Long-term balancing selection at the Phosphorus Starvation Tolerance 1 (PSTOL1) locus in wild, domesticated and weedy rice (Oryza).

    Science.gov (United States)

    Vigueira, Cynthia C; Small, Linda L; Olsen, Kenneth M

    2016-04-22

    The ability to grow in phosphorus-depleted soils is an important trait for rice cultivation in many world regions, especially in the tropics. The Phosphorus Starvation Tolerance 1 (PSTOL1) gene has been identified as underlying the ability of some cultivated rice varieties to grow under low-phosphorus conditions; however, the gene is absent from other varieties. We assessed PSTOL1 presence/absence in a geographically diverse sample of wild, domesticated and weedy rice and sequenced the gene in samples where it is present. We find that the presence/absence polymorphism spans cultivated, weedy and wild Asian rice groups. For the subset of samples that carry PSTOL1, haplotype sequences suggest long-term selective maintenance of functional alleles, but with repeated evolution of loss-of-function alleles through premature stops and frameshift mutations. The loss-of-function alleles have evolved convergently in multiple rice species and cultivated rice varieties. Greenhouse assessments of plant growth under low- and high-phosphorus conditions did not reveal significant associations with PSTOL1 genotype variation; however, the striking signature of balancing selection at this locus suggests that further phenotypic characterizations of PSTOL1 allelic variants is warranted and may be useful for crop improvement. These findings suggest balancing selection for both functional and non-functional PSTOL1 alleles that predates and transcends Asian rice domestication, a pattern that may reflect fitness tradeoffs associated with geographical variation in soil phosphorus content.

  9. A Tribal Story Written in Silica: Using Phytoliths to Research the Effects of Mining on Past Wild Rice (Zizania palustris) Abundance in Sandy Lake, Minnesota

    Science.gov (United States)

    Clarke, I. R.; Jones, M. A.; Yost, C. L.; Drake, C.; Ladwig, J. L.; Myrbo, A.; Howes, T.

    2014-12-01

    Wild rice (Zizania palustris, manoomin) is an emergent aquatic plant that grows annually in the northern Great Lakes region of North America. This region is also rich in iron ore deposits and correspondingly has an extensive history of mining activities. Wild rice no longer grows in some areas where it was previously abundant. Sandy Lake, located in St. Louis County on federally protected lands that are ceded territory of the Fond du Lac Band of Lake Superior Chippewa in Minnesota and downstream of the nearby U.S. Steel Minntac mine, was selected as a test site. This lake has a history of ricing activities by the Ojibwe (Chippewa) People, for whom manoomin has cultural importance. Lake cores were taken on June 17, 2014 by LacCore and FDLRM staff and samples were obtained. This project used phytolith analysis to answer the question of past wild rice presence and abundance in Sandy Lake. Phytoliths are microscopic opal silica deposits produced in some plants. Zizania palustris produces phytolith morphotypes that are unequivocally diagnostic of this species in this region. Microscopic slides were prepared and analyzed for wild rice phytoliths. Concentration values ranged from 25 to 4379 phytoliths per cm3/year, and wild rice accumulation figures ranged from 7 to 789 phytoliths/cm2/year, the maximum values of which occurred in the 1920s and generally declined to the current lowest levels observed. Mining has likely impacted wild rice populations by causing increased sulfate levels and possibly contributing to higher lake levels.

  10. Development and Validation of a TaqMan Real-Time PCR Assay for the Specific Detection and Quantification of Fusarium fujikuroi in Rice Plants and Seeds.

    Science.gov (United States)

    Carneiro, Greice Amaral; Matić, Slavica; Ortu, Giuseppe; Garibaldi, Angelo; Spadaro, Davide; Gullino, Maria Lodovica

    2017-07-01

    Bakanae disease, which is caused by the seedborne pathogen Fusarium fujikuroi, is found throughout the world on rice. A TaqMan real-time PCR has been developed on the TEF 1-α gene to detect F. fujikuroi in different rice tissues. Three primer/probe sets were tested. The selected set produced an amplicon of 84 bp and was specific for F. fujikuroi with respect to eight Fusarium species of rice and six other rice common pathogens. The assay was validated for specificity, selectivity, sensitivity, repeatability, and reproducibility. The detection limit was set at 27.5 fg of DNA, which is approximately equivalent to one haploid genome of F. fujikuroi. The developed TaqMan real-time assay was able to efficiently detect and quantify F. fujikuroi from rice culms, leaves, roots, and seeds. At 1 week post-germination (wpg), the pathogen was more diffused in the green tissues, while at 3 wpg it was uniformly spread also in the roots. The highest concentration of F. fujikuroi was measured in the M6 cultivar, which showed around 1,450 fungal cells/g. The assay was sufficiently sensitive to detect a few genomic equivalents in the rice seeds, corresponding to 9.89 F. fujikuroi cells/g. The assay permitted bakanae disease to be detected in asymptomatic tissues at the early rice development stages.

  11. Variation of Body Size in Rice Water Weevil (Coleoptera: Curculionidae) and Its Associations with Population Biology

    OpenAIRE

    Huang, Yunshan; Ao, Yan; Jiang, Mingxing; Way, Michael O

    2018-01-01

    Abstract Life history characteristics help us to determine the ability of invasive species to establish and thrive in an exotic environment. However, so far, there have been very few reports concerning geographic variation in the body size of invasive insects and the associations between body size variation and population biology. In this study, we surveyed the geographic variation in body size of an invasive agricultural pest, the rice water weevil Lissorhoptrus oryzophilus Kuschel (Coleopte...

  12. Genome-wide analysis of Dongxiang wild rice (Oryza rufipogon Griff.) to investigate lost/acquired genes during rice domestication.

    Science.gov (United States)

    Zhang, Fantao; Xu, Tao; Mao, Linyong; Yan, Shuangyong; Chen, Xiwen; Wu, Zhenfeng; Chen, Rui; Luo, Xiangdong; Xie, Jiankun; Gao, Shan

    2016-04-26

    It is widely accepted that cultivated rice (Oryza sativa L.) was domesticated from common wild rice (Oryza rufipogon Griff.). Compared to other studies which concentrate on rice origin, this study is to genetically elucidate the substantially phenotypic and physiological changes from wild rice to cultivated rice at the whole genome level. Instead of comparing two assembled genomes, this study directly compared the Dongxiang wild rice (DXWR) Illumina sequencing reads with the Nipponbare (O. sativa) complete genome without assembly of the DXWR genome. Based on the results from the comparative genomics analysis, structural variations (SVs) between DXWR and Nipponbare were determined to locate deleted genes which could have been acquired by Nipponbare during rice domestication. To overcome the limit of the SV detection, the DXWR transcriptome was also sequenced and compared with the Nipponbare transcriptome to discover the genes which could have been lost in DXWR during domestication. Both 1591 Nipponbare-acquired genes and 206 DXWR-lost transcripts were further analyzed using annotations from multiple sources. The NGS data are available in the NCBI SRA database with ID SRP070627. These results help better understanding the domestication from wild rice to cultivated rice at the whole genome level and provide a genomic data resource for rice genetic research or breeding. One finding confirmed transposable elements contribute greatly to the genome evolution from wild rice to cultivated rice. Another finding suggested the photophosphorylation and oxidative phosphorylation system in cultivated rice could have adapted to environmental changes simultaneously during domestication.

  13. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

    2015-01-01

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494

  14. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

    2015-05-27

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.

  15. Efficacy and economics of different herbicides in aerobic rice system

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... options for effective and economic weed control in rice under aerobic system ... constraint to aerobic rice production and therefore, ... Herbicide has become an attractive alternative to manual ... MATERIALS AND METHODS.

  16. Water culture of the rice containing Cs-137

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

    2008-10-01

    Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137

  17. Identification of quantitative trait loci for salinity tolerance in rice ...

    Indian Academy of Sciences (India)

    2016-12-05

    Dec 5, 2016 ... most serious biophysical constraints of rice production in many rice-producing areas ..... Thus, the large gaps in the chromosomal regions without ..... an elite maize population: I. Linkage analysis and determination of QTLs for.