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Sample records for asian cultivated rice

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

    Science.gov (United States)

    2010-01-01

    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 cultivated rice and that the close

  2. 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

  3. Paleogenomic Analysis of the Short Arm of Chromosome 3 Reveals the History of the African and Asian Progenitors of Cultivated Rices

    OpenAIRE

    Roulin, Anne; Chaparro, Cristian; Pi?gu, Benoit; Jackson, Scott; Panaud, Olivier

    2010-01-01

    Rice is one of the most important crops, feeding more than half of the world population. There are two cultivated species, the African rice Oryza glaberrima and the Asian rice O. sativa. Although the African species is gradually replaced by O. sativa in most of African rice agrosystems, this species represents an important reservoir of genes of agronomical interest. Their exploitation for the development of modern African rice varieties requires a good understanding of the genetic relationshi...

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Romain Guyot

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

  6. Paleogenomic analysis of the short arm of chromosome 3 reveals the history of the African and Asian progenitors of cultivated rices.

    Science.gov (United States)

    Roulin, Anne; Chaparro, Cristian; Piégu, Benoit; Jackson, Scott; Panaud, Olivier

    2010-02-11

    Rice is one of the most important crops, feeding more than half of the world population. There are two cultivated species, the African rice Oryza glaberrima and the Asian rice O. sativa. Although the African species is gradually replaced by O. sativa in most of African rice agrosystems, this species represents an important reservoir of genes of agronomical interest. Their exploitation for the development of modern African rice varieties requires a good understanding of the genetic relationships between the two cultivated species. We took advantage of the recent availability of the sequence of the chromosome 3 short arm of O. glaberrima to estimate the date of radiation between O. glaberrima and O. sativa lineages, using all the long terminal repeat (LTR)-retrotransposons as paleogenomic markers. We first demonstrated that in two distinct lineages, LTR-retrotransposons mutate at the same rate. Based on LTR-retrotransposons shared by both species in orthologous position, we then estimated that O. glaberrima and O. sativa progenitors diverged 1.2 Ma. This constitutes one of the first studies using such a large sample of transposable elements to reconstruct the phylogeny of species. Given the number of genome sequencing projects, there is no doubt that such approach will allow to resolve phylogenetic incongruities. The application of this method to other plant genomes will also facilitate further understanding of evolution of LTR-retrotransposons and eventually of the whole genome in divergent plant lineages.

  7. Three geographically separate domestications of Asian rice.

    Science.gov (United States)

    Civáň, Peter; Craig, Hayley; Cox, Cymon J; Brown, Terence A

    2015-11-02

    Domesticated rice (Oryza sativa L.) accompanied the dawn of Asian civilization(1) and has become one of world's staple crops. From archaeological and genetic evidence various contradictory scenarios for the origin of different varieties of cultivated rice have been proposed, the most recent based on a single domestication(2,3). By examining the footprints of selection in the genomes of different cultivated rice types, we show that there were three independent domestications in different parts of Asia. We identify wild populations in southern China and the Yangtze valley as the source of the japonica gene pool, and populations in Indochina and the Brahmaputra valley as the source of the indica gene pool. We reveal a hitherto unrecognized origin for the aus variety in central India or Bangladesh. We also conclude that aromatic rice is a result of a hybridization between japonica and aus, and that the tropical and temperate versions of japonica are later adaptations of one crop. Our conclusions are in accord with archaeological evidence that suggests widespread origins of rice cultivation(1,4). We therefore anticipate that our results will stimulate a more productive collaboration between genetic and archaeological studies of rice domestication, and guide utilization of genetic resources in breeding programmes aimed at crop improvement.

  8. Complete Chloroplast Genome Sequence and Annotation of the Tropical japonica Group of Asian Cultivated Rice (Oryza sativa L.)

    OpenAIRE

    Wang, Shuo; Gao, Li-zhi

    2016-01-01

    We announce here the first complete chloroplast genome sequence of the tropical japonica rice, along with its genome structure and functional annotation. The plant was collected from Indonesia and deposited as a germplasm accession of the International Rice GenBank Collection (IRGC 66630) at the International Rice Research Institute (IRRI). This genome provides valuable data for the future utilization of the germplasm of rice.

  9. The Origin of Flooded Rice Cultivation

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    Hiroshi IKEHASHI

    2007-09-01

    Full Text Available Rice cultivation has long been considered to have originated from seeding of annual types of wild rice somewhere in subtropics, tropics or in the Yangtze River basin. That idea, however, contains a fatally weak point, when we consider the tremendous difficulty for primitive human to seed any cereal crop in the warm and humid climate, where weed thrives all year round. Instead of the accepted theory, we have to see a reality that vegetative propagation of edible plants is a dominant form of agriculture in such regions. The possibility is discussed that Job's tears and rice, two cereal crops unique to the region, might have been developed via vegetative propagation to obtain materials for medicine or herb tea in backyard gardens prior to cereal production. This idea is supported by the fact that rice in temperate regions is still perennial in its growth habit and that such backyard gardens with transplanted taro can still be seen from Yunnan Province of China to Laos. Thanks to detailed survey of wild rice throughout China for 1970–1980, it is now confirmed that a set of clones of wild rice exist in shallow swamps in Jiangxi Province, an area with severe winter cold. In early summer ancient farmers may have divided the sprouting buds and spread them by transplanting into flooded shallow marsh. Such way of propagation might have faster improved less productive rice through a better genetic potential for response to human interference than quick fixation in seed propagation, because vegetative parts are heterogeneous. Obviously, such a primitive manner of rice cultivation did include the essential parts of rice farming, i.e., nursery bed, transplanting in flooded field of shallow marsh like. Transfer from the primitive nursery to true nursery by seed may have later allowed rice cultivation to be extended to northern regions. In thus devised flooded cultivation there were a series of unique advantages, i.e.; continuous cropping of rice in a same

  10. Soil Management Methods under Rice Cultivation in Ndokwa ...

    African Journals Online (AJOL)

    The study examines the soil management methods under rice cultivation in. Ndokwa grassland soils with the aim of determining the most effective soil management measures for rice cultivation. Soil samples were collected at three locations where rice is presently cultivated in the area. Five plots of 20m x 20m were ...

  11. Seed wintering and deterioration characteristics between weedy and cultivated rice

    OpenAIRE

    Baek, Jung-Sun; Chung, Nam-Jin

    2012-01-01

    Background Incidences of weedy rice continuously occurred in paddy fields because its shattering seeds were able to over-winter. In this research, the seed deterioration of weedy rice was investigated compared with cultivated rice, and the wintering characteristics of these two types of rice were investigated with the field wintering test, freezing resistance test, and accelerated aging test. Results For the wintering test, the seeds of weedy rice were placed on the soil surface of a paddy wi...

  12. 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.

  13. Farmers' perception of risk in cultivating hybrid rice in Bangladesh ...

    African Journals Online (AJOL)

    Although there is an enormous potential for improving adoption of hybrid rice in Bangladesh, it is going through some difficulties in practice. Understanding farmers' perception about difficulties is critical to successful promotion. The present study was conducted to analyze farmers' perception of risk in cultivating hybrid rice ...

  14. All roads lead to weediness: Patterns of genomic divergence reveal extensive recurrent weedy rice origins from South Asian Oryza.

    Science.gov (United States)

    Huang, Zhongyun; Young, Nelson D; Reagon, Michael; Hyma, Katie E; Olsen, Kenneth M; Jia, Yulin; Caicedo, Ana L

    2017-06-01

    Weedy rice (Oryza spp.), a weedy relative of cultivated rice (O. sativa), infests and persists in cultivated rice fields worldwide. Many weedy rice populations have evolved similar adaptive traits, considered part of the 'agricultural weed syndrome', making this an ideal model to study the genetic basis of parallel evolution. Understanding parallel evolution hinges on accurate knowledge of the genetic background and origins of existing weedy rice groups. Using population structure analyses of South Asian and US weedy rice, we show that weeds in South Asia have highly heterogeneous genetic backgrounds, with ancestry contributions both from cultivated varieties (aus and indica) and wild rice. Moreover, the two main groups of weedy rice in the USA, which are also related to aus and indica cultivars, constitute a separate origin from that of Asian weeds. Weedy rice populations in South Asia largely converge on presence of red pericarps and awns and on ease of shattering. Genomewide divergence scans between weed groups from the USA and South Asia, and their crop relatives are enriched for loci involved in metabolic processes. Some candidate genes related to iconic weedy traits and competitiveness are highly divergent between some weed-crop pairs, but are not shared among all weed-crop comparisons. Our results show that weedy rice is an extreme example of recurrent evolution, and suggest that most populations are evolving their weedy traits through different genetic mechanisms. © 2017 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2014-10-01

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

  16. Single-base resolution maps of cultivated and wild rice methylomes and regulatory roles of DNA methylation in plant gene expression

    DEFF Research Database (Denmark)

    Li, Xin; Zhu, Jingde; Hu, Fengyi

    2012-01-01

    DNA methylation plays important biological roles in plants and animals. To examine the rice genomic methylation landscape and assess its functional significance, we generated single-base resolution DNA methylome maps for Asian cultivated rice Oryza sativa ssp. japonica, indica and their wild...

  17. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ..., delivered to a processor, or stored for seed. Harvest. Combining or threshing the cultivated wild rice for... mature seeds naturally falling to the ground from a cultivated wild rice plant. 2. Unit Division...) of the Basic Provisions is not applicable to the cultivated wild rice seed that naturally shatters...

  18. Phylogeography of Asian wild rice, Oryza rufipogon: a genome-wide view.

    Science.gov (United States)

    Huang, Pu; Molina, Jeanmaire; Flowers, Jonathan M; Rubinstein, Samara; Jackson, Scott A; Purugganan, Michael D; Schaal, Barbara A

    2012-09-01

    Asian wild rice (Oryza rufipogon) that ranges widely across the eastern and southern part of Asia is recognized as the direct ancestor of cultivated Asian rice (O. sativa). Studies of the geographic structure of O. rufipogon, based on chloroplast and low-copy nuclear markers, reveal a possible phylogeographic signal of subdivision in O. rufipogon. However, this signal of geographic differentiation is not consistently observed among different markers and studies, with often conflicting results. To more precisely characterize the phylogeography of O. rufipogon populations, a genome-wide survey of unlinked markers, intensively sampled from across the entire range of O. rufipogon is critical. In this study, we surveyed sequence variation at 42 genome-wide sequence tagged sites (STS) in 108 O. rufipogon accessions from throughout the native range of the species. Using Bayesian clustering, principal component analysis and amova, we conclude that there are two genetically distinct O. rufipogon groups, Ruf-I and Ruf-II. The two groups exhibit a clinal variation pattern generally from north-east to south-west. Different from many earlier studies, Ruf-I, which is found mainly in China and the Indochinese Peninsula, shows genetic similarity with one major cultivated rice variety, O. satvia indica, whereas Ruf-II, mainly from South Asia and the Indochinese Peninsula, is not found to be closely related to cultivated rice varieties. The other major cultivated rice variety, O. sativa japonica, is not found to be similar to either O. rufipogon groups. Our results support the hypothesis of a single origin of the domesticated O. sativa in China. The possible role of palaeoclimate, introgression and migration-drift balance in creating this clinal variation pattern is also discussed. © 2012 Blackwell Publishing Ltd.

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

    Science.gov (United States)

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

    2016-06-01

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

  20. Single-base resolution maps of cultivated and wild rice methylomes and regulatory roles of DNA methylation in plant gene expression

    Directory of Open Access Journals (Sweden)

    Li Xin

    2012-07-01

    Full Text Available Abstract Background DNA methylation plays important biological roles in plants and animals. To examine the rice genomic methylation landscape and assess its functional significance, we generated single-base resolution DNA methylome maps for Asian cultivated rice Oryza sativa ssp. japonica, indica and their wild relatives, Oryza rufipogon and Oryza nivara. Results The overall methylation level of rice genomes is four times higher than that of Arabidopsis. Consistent with the results reported for Arabidopsis, methylation in promoters represses gene expression while gene-body methylation generally appears to be positively associated with gene expression. Interestingly, we discovered that methylation in gene transcriptional termination regions (TTRs can significantly repress gene expression, and the effect is even stronger than that of promoter methylation. Through integrated analysis of genomic, DNA methylomic and transcriptomic differences between cultivated and wild rice, we found that primary DNA sequence divergence is the major determinant of methylational differences at the whole genome level, but DNA methylational difference alone can only account for limited gene expression variation between the cultivated and wild rice. Furthermore, we identified a number of genes with significant difference in methylation level between the wild and cultivated rice. Conclusions The single-base resolution methylomes of rice obtained in this study have not only broadened our understanding of the mechanism and function of DNA methylation in plant genomes, but also provided valuable data for future studies of rice epigenetics and the epigenetic differentiation between wild and cultivated rice.

  1. Oyster mushroom cultivation with rice and wheat straw.

    Science.gov (United States)

    Zhang, Ruihong; Li, Xiujin; Fadel, J G

    2002-05-01

    Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.

  2. Rice Crop Monitoring by Earth Observation Data in the Asian Region

    Science.gov (United States)

    Oyoshi, K.; Sobue, S.; Tomiyama, N.; Okumura, T.; Rakwatin, P.

    2012-12-01

    Food security is a critical issue for the international community. In June 2011, the meeting of G20 agriculture ministers was held to discuss global food security and they agreed on an "Action Plan on Food Price Volatility and Agriculture". This plan includes a GEO Global Agricultural Monitoring (GEO-GLAM) initiative which utilizes remote sensing to improve projections of crop production and weather forecasting. Hence, satellite remote sensing is expected to contribute national, regional and global food security through the systematic and efficient collection of food security related information such as agro-meteorological condition, crop growth or yield estimation. Food security related information is utilized to take mitigation strategies or policies to manage food shortages or trading, and ensure food security. Especially in Asia, rice is the most important cereal crop because Asian countries are responsible for approximately 90% of the world rice productions and consumptions. There- fore, Asian countries are expected to contribute GLAM through the construction of rice crop monitoring system. We demonstrated the estimation of rice production, the crop phenology monitoring by Earth Observation (EO) data. The aim of this study is to establish a prototype system designed to provide paddy rice area and yield estimation. Generally, crop yield estimation is consist of two components, cultivated area and yield per area. The cultivated areas of paddy field are detected by the seasonal pattern of SAR data over paddy field. This means paddy field is filled with water just before planting rice, then covered by dense vegetation in growing season. The paddy filed map was derived from the seasonal Advanced Land Observation Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data with a simple threshold method. Then, to estimate rice productivity, we applied a simple rice crop model. The input data to the model are physical and chemical properties of

  3. Photosynthesis and Transpiration Rates of Rice Cultivated Under the System of Rice Intensification and the Effects on Growth and Yield

    Directory of Open Access Journals (Sweden)

    Nurul Hidayati

    2016-04-01

    Full Text Available The system of rice intensification (SRI crop management method has been reported by many authors to significantly increase rice yield with lower inputs, but physiological bases of yielding improvement has not been studied. In this research we assessed some physiological parameters and the mechanism of rice yield improvement of rice plants under SRI cultivation method during both vegetative and generative phases compared to conventional rice cultivation methods. We measured photosynthetic rate, transpiration rate, leaf temperature, chlorophyll content, N and P uptake, plant growth parameters and yield for those comparison. SRI methods significantly increased both vegetative and reproductive (generative parameters of rice plants compared to conventional cultivation methods. Photosynthetic rate, chlorophyll content, N and P uptake under SRI cultivation were significantly higher compared to those of the conventional rice cultivation, but no differences were found in transpiration rate and leaf temperature. With SRI method, plants in their generative phase (especially in the grain-filling phase had the highest photosynthetic and the lowest transpiration rates. Grain yield under SRI method was significantly higher (ca. 24% than that of conventional method.

  4. Improving Yield of Transplanted Aman and Boro Rice Through Tegra Package of Cultivation

    Directory of Open Access Journals (Sweden)

    MA Kader, MSR Mia, MA Kafi, MS Hossain, N Islam

    2015-12-01

    Full Text Available The study investigated the yield performance of transplant aman rice cv. BRRI dhan49 and boro rice cv. BRRI dhan29 under improved package of cultivation (TEGRA as compared to farmers’ practice. TEGRA is a rice farming practice which includes use of quality seeds and healthy seedlings, transplanting with rice transplanter, use of herbicide, use of balanced fertilization and micronutrients, and preventive plant protection measures. The study during transplant aman season included two treatments on rice cultivation method viz. TEGRA package and farmers’ practice while in boro rice four treatments viz. TEGRA package, farmers’ practice with high inputs, farmers’ practice with medium inputs and farmers’ practice with low inputs. The yield and plant characters of both transplant aman and boro rice were significantly influenced by the TEGRA package of cultivation as compared to farmers’ practice. TEGRA package of cultivation as compared to farmers’ practice increased the grain yield by 18.3% in transplant aman rice and by 80% in boro rice with less cost of production as compared to farmers’ practice, which eventually resulted 23% increase in gross return and 400% in net return. As a result, the benefit cost ratio of TEGRA package was much higher (1.35 and 2.20 during transplant aman rice and boro rice, respectively compared to that of farmers’ practice (1.07 and 1.30.

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

    Science.gov (United States)

    Abeysinghe, Kasun S; Qiu, Guangle; Goodale, Eben; Anderson, Christopher W N; Bishop, Kevin; Evers, David C; Goodale, Morgan W; Hintelmann, Holger; Liu, Shengjie; Mammides, Christos; Quan, Rui-Chang; Wang, Jin; Wu, Pianpian; Xu, Xiao-Hang; Yang, Xiao-Dong; Feng, Xinbin

    2017-10-01

    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. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

  7. Implications of Water Use and Water Scarcity Footprint for Sustainable Rice Cultivation

    Directory of Open Access Journals (Sweden)

    Thapat Silalertruksa

    2017-12-01

    Full Text Available Rice cultivation is a vital economic sector of many countries in Asia, including Thailand, with the well-being of people relying significantly on selling rice commodities. Water-intensive rice cultivation is facing the challenge of water scarcity. The study assessed the volumetric freshwater use and water scarcity footprint of the major and second rice cultivation systems in the Chao Phraya, Tha Chin, Mun, and Chi watersheds of Thailand. The results revealed that a wide range of freshwater use, i.e., 0.9–3.0 m3/kg of major rice and 0.9–2.3 m3/kg of second rice, and a high water use of rice was found among the watersheds in the northeastern region, like the Mun and Chi watersheds. However, the water scarcity footprint results showed that the second rice cultivation in watersheds, like in Chao Phraya and Tha Chin in the central region, need to be focused for improving the irrigation water use efficiency. The alternate wetting and drying (AWD method was found to be a promising approach for substituting the pre-germinated seed broadcasting system to enhance the water use efficiency of second rice cultivation in the central region. Recommendations vis-à-vis the use of the water stress index as a tool for agricultural zoning policy were also discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongbo, E-mail: liuyb@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Liu, Fang [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Chao [Pearl River Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510380 (China); Quan, Zhanjun [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Junsheng, E-mail: lijsh@creas.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

    2016-09-15

    The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking. - Highlights: • We detect fusion Cry1Ab/1Ac proteins from Bt rice entering into aquatic ecosystems. • Bt-transgenic rice cultivation have no significant effect on zooplankton community. • Bt-transgenic rice cultivation have indirect effect on phytoplankton community. • Water quality explains the difference of plankton communities in adjacent ditches.

  9. Rice Chloroplast Genome Variation Architecture and Phylogenetic Dissection in Diverse Oryza Species Assessed by Whole-Genome Resequencing.

    Science.gov (United States)

    Tong, Wei; Kim, Tae-Sung; Park, Yong-Jin

    2016-12-01

    Chloroplast genome variations have been detected, despite its overall conserved structure, which has been valuable for plant population genetics and evolutionary studies. Here, we described chloroplast variation architecture of 383 rice accessions from diverse regions and different ecotypes, in order to mine the rice chloroplast genome variation architecture and phylogenetic. A total of 3677 variations across the chloroplast genome were identified with an average density of 27.33 per kb, in which wild rice showing a higher variation density than cultivated groups. Chloroplast genome nucleotide diversity investigation indicated a high degree of diversity in wild rice than in cultivated rice. Genetic distance estimation revealed that African rice showed a low level of breeding and connectivity with the Asian rice, suggesting the big distinction of them. Population structure and principal component analysis revealed the existence of clear clustering of African and Asian rice, as well as the indica and japonica in Asian cultivated rice. Phylogenetic analysis based on maximum likelihood and Bayesian inference methods and the population splits test suggested and supported the independent origins of indica and japonica within Asian cultivated rice. In addition, the African cultivated rice was thought to be domesticated differently from Asian cultivated rice. The chloroplast genome variation architecture in Asian and African rice are different, as well as within Asian or African rice. Wild rice and cultivated rice also have distinct nucleotide diversity or genetic distance. In chloroplast level, the independent origins of indica and japonica within Asian cultivated rice were suggested and the African cultivated rice was thought to be domesticated differently from Asian cultivated rice. These results will provide more candidate evidence for the further rice chloroplast genomic and evolution studies.

  10. Evaluation of nutrients status of soils under rice cultivation in cross ...

    African Journals Online (AJOL)

    Nutrients status of soils under rice cultivation in Cross River State Nigeria was evaluated to ascertain the present status and suggest management practices needed for an increased rice production. A reconnaissance survey of the entire State was undertaken. A total number of eight Local Government Areas, namely ...

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

    NARCIS (Netherlands)

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

    2015-01-01

    2-bromoethanesulfonate (BES) is a structural analogue of coenzyme M (Co-M) and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied.

  12. Pythium spp. affecting aerobic rice cultivation in the Philippines: characterization, virulence strategies and plant defense

    OpenAIRE

    Van Buyten, Evelien

    2013-01-01

    Global warming and a continuously rising world population are causing water scarcity for agricultural usage. The traditional rice cultivation in flooded paddy fields consumes tremendous amounts of fresh water and therefore, its sustainability is severely threatened. Since rice paddies provide 75% of the total rice production, this poses a huge problem on the future food security of billions of people mainly living in Asia. Several strategies have been developed to save water in paddy fields, ...

  13. Soil Management Methods under Rice Cultivation in Ndokwa ...

    African Journals Online (AJOL)

    User

    ... properties in the soil using the most probable instruments and analytical methods. The yield of rice harvested was measured in tons per hectares (He). The results revealed that the application of soil management techniques has enhanced rice yields by. 23.45tons/He. The combination of slash and burn, tillage and soil.

  14. Resequencing 50 accessions of cultivated and wild rice yields markers for identifying agronomically important genes

    DEFF Research Database (Denmark)

    Xu, Xun; Liu, Xin; Ge, Song

    2012-01-01

    Rice is a staple crop that has undergone substantial phenotypic and physiological changes during domestication. Here we resequenced the genomes of 40 cultivated accessions selected from the major groups of rice and 10 accessions of their wild progenitors (Oryza rufipogon and Oryza nivara) to >15 x...... raw data coverage. We investigated genome-wide variation patterns in rice and obtained 6.5 million high-quality single nucleotide polymorphisms (SNPs) after excluding sites with missing data in any accession. Using these population SNP data, we identified thousands of genes with significantly lower...... diversity in cultivated but not wild rice, which represent candidate regions selected during domestication. Some of these variants are associated with important biological features, whereas others have yet to be functionally characterized. The molecular markers we have identified should be valuable...

  15. Little white lies: pericarp color provides insights into the origins and evolution of Southeast Asian weedy rice

    Science.gov (United States)

    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy ...

  16. Allelopathy: Potential Role to Achieve New Milestones in Rice Cultivation

    Directory of Open Access Journals (Sweden)

    M.K. Amb

    2016-07-01

    Full Text Available Rice fields are ecosystems with many types of plants, microbes, invertebrates, birds and animals. The rice farming protects the biodiversity of the region and maintains the ecosystem for the benefit of environment. Some rice varieties release biocidal allelochemicals which might affect major weeds, microbial and pathogenic diversity around rice plants, even soil characteristics. A large number of compounds such as phenolic acids, fatty acids, indoles and terpenes have been identified in rice root exudates and decomposing rice residues, as putative allelochemicals which can interact with surrounding environment. Since these allelopathic interactions may be positive, they can be used as effective contributor for sustainable and eco-friendly agro-production system. Genetic modification of crop plants to improve their allelopathic properties and enhancement of desirable traits has been suggested. Development of crops with enhanced allelopathic traits by genetic modification should be done cautiously, keeping in view of the ecological risk assessment (non-toxic and safe for humans and ecosystem, crop productivity, ratio of benefit and cost, etc..

  17. Mapping regional risks from climate change for rainfed rice cultivation in India.

    Science.gov (United States)

    Singh, Kuntal; McClean, Colin J; Büker, Patrick; Hartley, Sue E; Hill, Jane K

    2017-09-01

    Global warming is predicted to increase in the future, with detrimental consequences for rainfed crops that are dependent on natural rainfall (i.e. non-irrigated). Given that many crops grown under rainfed conditions support the livelihoods of low-income farmers, it is important to highlight the vulnerability of rainfed areas to climate change in order to anticipate potential risks to food security. In this paper, we focus on India, where ~ 50% of rice is grown under rainfed conditions, and we employ statistical models (climate envelope models (CEMs) and boosted regression trees (BRTs)) to map changes in climate suitability for rainfed rice cultivation at a regional level (~ 18 × 18 km cell resolution) under projected future (2050) climate change (IPCC RCPs 2.6 and 8.5, using three GCMs: BCC-CSM1.1, MIROC-ESM-CHEM, and HadGEM2-ES). We quantify the occurrence of rice (whether or not rainfed rice is commonly grown, using CEMs) and rice extent (area under cultivation, using BRTs) during the summer monsoon in relation to four climate variables that affect rice growth and yield namely ratio of precipitation to evapotranspiration ( PER ), maximum and minimum temperatures ( T max and T min ), and total rainfall during harvesting. Our models described the occurrence and extent of rice very well (CEMs for occurrence, ensemble AUC = 0.92; BRTs for extent, Pearson's r = 0.87). PER was the most important predictor of rainfed rice occurrence, and it was positively related to rainfed rice area, but all four climate variables were important for determining the extent of rice cultivation. Our models project that 15%-40% of current rainfed rice growing areas will be at risk (i.e. decline in climate suitability or become completely unsuitable). However, our models project considerable variation across India in the impact of future climate change: eastern and northern India are the locations most at risk, but parts of central and western India may benefit from increased

  18. Advanced geospatial techniques and archaeological methods to investigate historical rice cultivation at Wormsloe Historic Site

    Science.gov (United States)

    Alessandro Pasqua

    2016-01-01

    Despite much of the environmental history of Wormsloe State Historic Site on the Isle of Hope, Georgia having previously been documented and described, there are still some aspects that require deeper investigation. For example, whether rice cultivation was ever performed at Wormsloe is a question which does not have a definitive answer.

  19. Rice, weeds and shifting cultivation in a tropical rain forest : a study of vegetation dynamics

    NARCIS (Netherlands)

    Rouw, de A.

    1991-01-01

    The study deals with the rain forest area in south-west Côte d'lvoire (Taï National Park). Descriptions are given of the area's history, agricultural practices, geology, geomorphology, soils, flora and vegetation. The shifting cultivation system based on upland rice was studied as it is

  20. Soil Management Methods under Rice Cultivation in Ndokwa ...

    African Journals Online (AJOL)

    User

    Soil samples were collected and analyzed for physical, chemical and heavy metals properties in the soil using the most probable instruments and analytical methods. The yield of rice harvested was measured in tons per hectares (He). The results revealed that the application of soil management techniques has enhanced ...

  1. Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... ed through interspecific hybridization of Asian and African rice, formed a cluster with Asian rice. Generally cultivated and wild species clearly observed to have separated groups in both UPGMA and neighbor joining analysis. The two methods showed almost the same tree topology with similar groupings ...

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

    Science.gov (United States)

    He, Ruifeng; Salvato, Fernanda; Park, Jeong-Jin; Kim, Min-Jeong; Nelson, William; Balbuena, Tiago S; Willer, Mark; Crow, John A; May, Greg D; Soderlund, Carol A; Thelen, Jay J; Gang, David R

    2014-02-12

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

  3. Assessment of reclaimed wastewater irrigation impacts on water quality, soil, and rice cultivation in paddy fields.

    Science.gov (United States)

    Kang, Moon Seong; Kim, Sang Min; Park, Seung Woo; Lee, Jeong Jae; Yoo, Kyung H

    2007-03-01

    The objective of this research was to monitor and assess the impact of reclaimed wastewater irrigation on water quality, soil, and rice cultivation by comparing the effects of various wastewater treatment levels on the growth and yield of rice. A randomized complete block design was used for the application methods of the wastewater effluents to paddy rice, with five treatments and six replications. The treatments were: control with groundwater irrigation (GW); irrigation with polluted water form a nearby stream (SW); and three treatments of reclaimed wastewater irrigation at different treatment levels. The three levels of wastewater treatments included wastewater effluents: (i) directly from the wastewater plant (WW); (ii) after passing through a sand filter (WSF); and (iii) after passing a sand filter followed by an ultraviolet treatment (WSFUV). Each plot was 4 x 4 m and was planted with rice (Oryza sativa L.) in 2002 and 2003. The results indicated that irrigation of rice with reclaimed municipal wastewater caused no adverse effects on the growth and yield of rice. The chemical compositions of the rice from all plots were within the normal ranges of brown rice quality in Korea. No adverse effects were observed on chemical concentrations including the heavy metals Cu, As, Cd, Zn, Hg, and Pb, in either the brown rice or the field. The results showed that treated municipal wastewater can be safely used as an alternative water source for the irrigation of rice, although continued monitoring will be needed to determine the long-term effects with regard to soil contamination and other potential health concerns.

  4. Initiation and Dissemination of Organic Rice Cultivation in Bali, Indonesia

    Directory of Open Access Journals (Sweden)

    Fumitaka Shiotsu

    2015-04-01

    Full Text Available Organic farming has attracted attention in Indonesia because consumers increasingly prefer the putative safety and health benefits of organic farm products. Although national standards for organic farm products were established in 2002, some products sold as organic products in supermarkets do not carry the certification mark. This study investigated organic rice farming on the island of Bali in Indonesia using fieldwork to ascertain the actual increase in organic farming. Results revealed that government certified organic farming used originally produced cattle manure to grow organic rice. At the market, however, some “quasi-organic farming” products, which had not been given the organic farming certification, were sold as organic rice. This eventuality suggests that although organic farming has been increasing steadily in Bali, development of sustainable recycling agriculture demands technical guidance and increased publicity for organic farming, based on national certification, to address misunderstandings and confusion about the definitions of organic farming and national standards that are transparent to producers and consumers.

  5. Rice improvement through radiation-induced mutation for cultivation in South Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh [Institute of Agricultural Science of South Vietnam, Ho Chi Minh (Viet Nam)

    2001-03-01

    For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of {sup 60}Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With {sup 60}Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

  6. Reduced weed seed shattering by silencing a cultivated rice gene: strategic mitigation for escaped transgenes.

    Science.gov (United States)

    Yan, Huanxin; Li, Lei; Liu, Ping; Jiang, Xiaoqi; Wang, Lei; Fang, Jia; Lin, Zhimin; Wang, Feng; Su, Jun; Lu, Bao-Rong

    2017-08-01

    Transgene flow form a genetically engineered (GE) crop to its wild relatives may result in unwanted environmental consequences. Mitigating transgenes via introducing a gene that is disadvantageous to wild relatives but beneficial to crops, and is tightly-linked with the target transgenes, may provide a promising solution to limit the spread of transgenes in wild/weedy populations. Here we demonstrate a novel system with significantly reduced seed shattering in crop-weed hybrid descendants by partially silenced expression of the seed-shattering gene SH4 in cultivated rice, using artificial microRNA and antisense RNA techniques. Accordingly, fewer seeds were found in the soil of the field plots where transgenic hybrid lineages were grown. However, no differences in productivity-related traits were detected between GE and non-GE cultivated rice. To silence seed-shattering genes provides a useful strategy to reduce the potential environmental impacts caused by transgene flow from commercial GE rice to weedy rice, in addition to the control of weedy rice.

  7. Effects of screenhouse cultivation and organic materials incorporation on global warming potential in rice fields.

    Science.gov (United States)

    Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Xiong, Ruiheng; Hang, Yuhao

    2017-03-01

    Global rice production will be increasingly challenged by providing healthy food for a growing population at minimal environmental cost. In this study, a 2-year field experiment was conducted to investigate the effects of a novel rice cultivation mode (screenhouse cultivation, SHC) and organic material (OM) incorporation (wheat straw and wheat straw-based biogas residue) on methane (CH 4 ) and nitrous oxide (N 2 O) emissions and rice yields. In addition, the environmental factors and soil properties were also determined. Relative to the traditional open-field cultivation (OFC), SHC decreased the CH 4 and N 2 O emissions by 6.58-18.73 and 2.51-21.35%, respectively, and the global warming potential (GWP) was reduced by 6.49-18.65%. This trend was mainly because of lower soil temperature and higher soil redox potential in SHC. Although the rice grain yield for SHC were reduced by 2.51-4.98% compared to the OFC, the CH 4 emissions and GWP per unit of grain yield (yield-scaled CH 4 emissions and GWP) under SHC were declined. Compared to use of inorganic fertilizer only (IN), combining inorganic fertilizer with wheat straw (WS) or wheat straw-based biogas residue (BR) improved rice grain yield by 2.12-4.10 and 4.68-5.89%, respectively. However, OM incorporation enhanced CH 4 emissions and GWP, leading to higher yield-scaled CH 4 emissions and GWP in WS treatment. Due to rice yield that is relatively high, there was no obvious effect of BR treatment on them. These findings suggest that apparent environmental benefit can be realized by applying SHC and fermenting straw aerobically before its incorporation.

  8. Nutrient Removal by Rice Cultivated in Newly Opened Wetland Rice in Bulungan District, East Kalimantan

    Directory of Open Access Journals (Sweden)

    Sukristiyonubowo

    2012-05-01

    Full Text Available Highly weathered Indonesian soils and potential acid sulphate soils are mainly granted for developing newlyopened wetland rice field to meet rice growing demand in Indonesia. Nutrient removal by rice harvest product ofCiliwung variety planted in newly opened wetland rice was studied in Bulungan District, in 2009. The aims were toexamine the nutrient taken out by rice harvest product and to properly manage its fertility status to sustain ricefarming. Six treatments were studied including T0: farmers practices, T1: farmer practices + compost + dolomite, T2:NPK recommended rate, N and K were split two times, T3: NPK recommended rate, N and K were split three times,T4: NPK recommended rate, N and K were split three times + compost + dolomite and T5: NPK recommended rate,N and K were split two times + compost + dolomite. The results indicated that the highest concentrations of N, P,and K in rice grain and rice straw were observed at NPK with recommendation rate in which N and K were split threetimes + straw compost + dolomite (T4. The T4 (NPK with recommendation rate in which N and K were split threetimes + straw compost + dolomite also showed the highest nutrient removal by harvest product. Depending on thetreatments, total nutrients removal through rice grains and rice straw varied from 61.81 to 101.71 kg N, 4.31 to13.69 kg P and from 95.77 to 171.16 kg K ha-1 season-1, meaning that at least about 137 to 225 kg urea, 50 to 160kg SP-36 and 190 to 339 kg KCl ha-1 season-1 should be given to replace nutrient removed by harvest product andto avoid any nutrients depletion. When all rice straws were returned to the field as compost, about 55 to 133 kg urea,25 to 110 kg SP-36 and 10 to 19 kg KCl ha-1 season-1 should be added to substitute nutrient removed by rice grain.

  9. Implication of blue green algae on yield attributes and economics of rice cultivation

    OpenAIRE

    Ranjana Sinha

    2017-01-01

    Indian agriculture is presently at cross roads as it has to increase output at one hand and has to take care of environmental aspects on the other hand. Rice cultivation is also facing the same dilemma. Use of blue green algae as bio fertilizer is one possible way to minimize application of synthetic fertilizers which have far reaching implications on environment and health. Present research study was formulated to screen most suitable combination of different species of cyanobacteria on yiel...

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

    Science.gov (United States)

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

    2015-08-01

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

  11. Remote sensing-based Information for crop monitoring: contribution of SAR and Moderate resolution optical data on Asian rice production

    Science.gov (United States)

    Boschetti, Mirco; Holectz, Francesco; Manfron, Giacinto; Collivignarelli, Francesco; Nelson, Andrew

    2013-04-01

    Updated information on crop typology and status are strongly required to support suitable action to better manage agriculture production and reduce food insecurity. In this field, remote sensing has been demonstrated to be a suitable tool to monitor crop condition however rarely the tested system became really operative. The ones today available, such as the European Commission MARS, are mainly based on the analysis of NDVI time series and required ancillary external information like crop mask to interpret the seasonal signal. This condition is not always guarantied worldwide reducing the potentiality of the remote sensing monitoring. Moreover in tropical countries cloud contamination strongly reduce the possibility of using optical remote sensing data for crop monitoring. In this framework we focused our analysis on the rice production monitoring in Asian tropical area. Rice is in fact the staple food for half of the world population (FAO 2004), in Asia almost 90% of the world's rice is produced and consumed and Rice and poverty often coincide. In this contest the production of reliable rice production information is of extreme interest. We tried to address two important issue in terms of required geospatial information for crop monitoring: rice crop detection (rice map) and seasonal dynamics analysis (phenology). We use both SAR and Optical data in order to exploit the potential complementarity of this system. Multi-temporal ASAR Wide Swath data are in fact the best option to deal with cloud contamination. SAR can easily penetrate the clouds providing information on the surface target. Temporal analysis of archive ASAR data allowed to derived accurate map, at 100m spatial resolution, of permanent rice cultivated areas. On the other and high frequency revisiting optical data, in this case MODIS, have been used to extract seasonal information for the year under analysis. MOD09A1 Surface Reflectance 8-Day L3 Global 500m have been exploited to derive time series of

  12. Determination of genetic variability of Asian rice (Oryza sativa L ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... context of global biodiversity loss, Pakistan missed seve- ral rice varities. Therefore, it is highly necessary ... are promising and effective tools for measuring genetic diversity in plants germplasm and elucidating .... measure the genetic similarity by Dice coefficients. The Dice co- efficients were employed by ...

  13. Submergence rice cultivation in southern Bangladesh: farmers opinion and adaptations practices

    Directory of Open Access Journals (Sweden)

    AKM Abdul Ahad Biswas

    2015-12-01

    Full Text Available Rice productivity in coastal Bangladesh is lower than the national average and total coastal area is considered to be submergence-prone and higher vulnerable in July to January cropping season. The selected study areas are Kalapara and Patuakhali Sadar Upazila that are too vulnerable to agriculture practices. Field survey was conducted during 01st June to 30th July, 2015 to investigate the impact of submergence on Aman rice cultivation (ARC, existing adopted local adaptation practices with impacts and options to address the submergence problem. Primary data was collected through Focus Group Discussion (FGD, Individual Interview and Key Informant Interview methods and secondary data was collected from different secondary sources. A well-structured pretested questionnaire schedule was developed keeping in mind the objectives and variables under this study. After cyclone SIDR and AILA devastation, the rate of traditional ARC is decreasing every year and in 2015 it was 26.51%. Recently farmers have adopted new cropping practices and strategies like modern ARC in Aman season as single crop; Boro-Aus-Aman season as triple crop and Aus-Aman season as double crop are practicing. Approximately all farmers have adopted to grow stress tolerant rice varieties (STRV; farmer’s curiosities to familiar with and to have the STRV are encouraging. Farmers were fully adopted BRRIdhan52 rice cultivation with positive perceptions of higher yield and lower production cost. Therefore it can be concluded that the intensity of adoption of adaptation and mitigation measures are significantly influenced positively by the STRV yield capability; farmer’s participation in intervention programs; livelihood diversification; frequency of extension personnel contact; submergence and inundation characteristics; tolerance attributes of STRV and availability of STRV cultivation information.International Journal of Environment Vol.4(4 2015: 100-113

  14. Evolutionary Insights Based on SNP Haplotypes of Red Pericarp, Grain Size and Starch Synthase Genes in Wild and Cultivated Rice

    Directory of Open Access Journals (Sweden)

    Nisha Singh

    2017-06-01

    Full Text Available The origin and domestication of rice has been a subject of considerable debate in the post-genomic era. Rice varieties have been categorized based on isozyme and DNA markers into two broad cultivar groups, Indica and Japonica. Among other well-known cultivar groups Aus varieties are closer to Indica and Aromatic varieties including Basmati are closer to Japonica, while deep-water rice varieties share kinship to both Indica and Japonica cultivar groups. Here, we analyzed haplotype networks and phylogenetic relationships in a diverse set of genotypes including Indian Oryza nivara/Oryza rufipogon wild rice accessions and representative varieties of four rice cultivar groups based on pericarp color (Rc, grain size (GS3 and eight different starch synthase genes (GBSSI, SSSI, SSIIa, SSIIb, SSIIIa, SSIIIb, SSIVa, and SSIVb. Aus cultivars appear to have the most ancient origin as they shared the maximum number of haplotypes with the wild rice populations, while Indica, Japonica and Aromatic cultivar groups showed varying phylogenetic origins of these genes. Starch synthase genes showed higher variability in cultivated rice than wild rice populations, suggesting diversified selection during and after domestication. O. nivara/O. rufipogon wild rice accessions belonging to different sub-populations shared common haplotypes for all the 10 genes analyzed. Our results support polyphyletic origin of cultivated rice with a complex pattern of migration of domestication alleles from wild to different rice cultivar groups. The findings provide novel insights into evolutionary and domestication history of rice and will help utilization of wild rice germplasm for genetic improvement of rice cultivars.

  15. Evolutionary Insights Based on SNP Haplotypes of Red Pericarp, Grain Size and Starch Synthase Genes in Wild and Cultivated Rice

    Science.gov (United States)

    Singh, Nisha; Singh, Balwant; Rai, Vandna; Sidhu, Sukhjeet; Singh, Ashok K.; Singh, Nagendra K.

    2017-01-01

    The origin and domestication of rice has been a subject of considerable debate in the post-genomic era. Rice varieties have been categorized based on isozyme and DNA markers into two broad cultivar groups, Indica and Japonica. Among other well-known cultivar groups Aus varieties are closer to Indica and Aromatic varieties including Basmati are closer to Japonica, while deep-water rice varieties share kinship to both Indica and Japonica cultivar groups. Here, we analyzed haplotype networks and phylogenetic relationships in a diverse set of genotypes including Indian Oryza nivara/Oryza rufipogon wild rice accessions and representative varieties of four rice cultivar groups based on pericarp color (Rc), grain size (GS3) and eight different starch synthase genes (GBSSI, SSSI, SSIIa, SSIIb, SSIIIa, SSIIIb, SSIVa, and SSIVb). Aus cultivars appear to have the most ancient origin as they shared the maximum number of haplotypes with the wild rice populations, while Indica, Japonica and Aromatic cultivar groups showed varying phylogenetic origins of these genes. Starch synthase genes showed higher variability in cultivated rice than wild rice populations, suggesting diversified selection during and after domestication. O. nivara/O. rufipogon wild rice accessions belonging to different sub-populations shared common haplotypes for all the 10 genes analyzed. Our results support polyphyletic origin of cultivated rice with a complex pattern of migration of domestication alleles from wild to different rice cultivar groups. The findings provide novel insights into evolutionary and domestication history of rice and will help utilization of wild rice germplasm for genetic improvement of rice cultivars. PMID:28649256

  16. 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.

  17. Water Productivity of Irrigated Rice under Transplanting, Wet Seeding and Dry Seeding Methods of Cultivation

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    Murali, NS.

    1997-01-01

    Full Text Available Water productivity (WP of irrigated lowland rice was determined during the 1994 dry (January to May and wet (August to December seasons on a heavy clay acid sulphate soil. Treatments consisted of three cultivation methods : transplanted rice, pregerminated seeds broadcasted on puddled soil (wet seeding and dry seeds broadcasted on unpuddled soil (dry seeding. In wet and dry seeded plots, continuous standing water condition was initiated 17 days after sowing. Total water requirement for rice production was highest in transplanted plots (755 mm in wet season and 1154 mm in dry season and was lowest in dry seeded plots (505 mm in wet season and 1040 mm in dry season. Dry seeding required no water for land preparation but transplanting and wet seeding methods required 18 - 20 % of total water requirement in dry season and 27 - 29 % in wet season. Total percolation was maximum (99 mm in wet season and 215 mm in dry season in dry seeding method and was minimum (62 mm in wet season and 94 mm in dry season in transplanting method. In dry and wet seeding methods, daily percolation gradually decreased with the age of the crop. Total seepage loss did not show any significant difference between the cultivation methods in the two seasons. Grain yield was not affected by the three cultivation methods in both seasons. Water productivity (the ratio between grain yield and total amount of water used in production was 3.5 - 4.1 kg ha-1 mm-1, 3.8 - 4.4 kg ha-1 mm-1 and 4.1 - 5.5 kg ha-1 mm-1 in transplanted, wet seeded and dry seeded rice, respectively. Labour requirement for land preparation and sowing was maximum in transplanted (219 - 226 man-hours ha-1 followed by wet (104 -112 man-hours ha-1 and dry seeded (94 - 99 man-hours ha-1 methods. However, in wet season extra labour (77 man-hours ha-1 was required for weeding after crop establishment in dry and wet seeding methods. Crop maturity was 20 days earlier in wet and dry seeding methods compared to

  18. Cultivating Medical Intentionality: The Phenomenology of Diagnostic Virtuosity in East Asian Medicine.

    Science.gov (United States)

    Kim, Taewoo

    2017-03-01

    This study examines the perceptual basis of diagnostic virtuosity in East Asian medicine, combining Merleau-Ponty's phenomenology and an ethnographic investigation of Korean medicine in South Korea. A novice, being exposed to numerous clinical transactions during apprenticeship, organizes perceptual experience that occurs between him or herself and patients. In the process, the fledgling practitioner's body begins to set up a medically-tinged "intentionality" interconnecting his or her consciousness and medically significant qualities in patients. Diagnostic virtuosity is gained when the practitioner embodies a cultivated medical intentionality. In the process of becoming a practitioner imbued with virtuosity, this study focuses on the East Asian notion of "Image" that maximizes the body's perceptual capacity, and minimizes possible reductions by linguistic re-presentation. "Image" enables the practitioner to somatically conceptualize the core notions of East Asian medicine, such as Yin-Yang, and to use them as an embodied litmus as the practitioner's cultivated body instinctively conjures up medical notions at clinical encounters. In line with anthropological critiques of reductionist frameworks that congeal human existential and perceptual vitality within a "scientific" explanatory model, this article attempts to provide an example of various knowing and caring practices, institutionalized external to the culture of science.

  19. Greenhouse Gas Emissions from Peat Soils Cultivated to Rice Field, Oil Palm and Vegetable

    Directory of Open Access Journals (Sweden)

    Rosenani Abu Bakar

    2012-05-01

    Full Text Available Presently, about 20% of oil palm (Elaeis guineensis Jacq fields in Indonesia are on peat soil, in addition to that otherarea of peat soil has been conventionally used for rice field and vegetables. To elucidate the global warmingpotentials of peat soils cultivated to oil palm, vegetable or rice field, field experiment has been carried out in SouthKalimantan. Air samples were taken from rice field, oil palm and vegetable fields in weekly basis for six month periodand analyzed for concentrations of N2O, CH4 and CO2. The global warming potentials (GWP of the three gases werecalculated by multiplying the emission of each gas with their respective mole warming potential. This step wasfollowed by the addition of the three gases’ GWP to have the total GWP. The results showed that the emissions ofgreenhouse gases from peat soils changed seasonally and varied with the crops cultivated. Oil palm has resultedthe highest GWP, mostly contributed by N2O. There was no statistical different in total GWP of paddy andvegetable fields. The annual N2O emission from oil palm field was 4,582 g N ha-1 yr-1. Water, nutrients and organicmatter managements are among the potential techniques to minimize gas emissions from oil palm field which needfield trials.

  20. Glycaemic and insulin responses, glycaemic index and insulinaemic index values of rice between three Asian ethnic groups.

    Science.gov (United States)

    Tan, V M H; Wu, T; Henry, C J; Lee, Y S

    2015-04-28

    Asians exhibit larger glycaemic response (GR) and insulin response (IR) than Caucasians, predisposing to an increased risk of type 2 diabetes mellitus (T2DM). We aimed to determine the GR and IR as well as the glycaemic index (GI) and insulinaemic index (II) of two rice varieties among three ethnic groups in Singapore. A total of seventy-five healthy males (twenty-five Chinese, twenty-five Malay and twenty-five Asian-Indians) were served the available equivalent carbohydrate amounts (50 g) of test foods (Jasmine rice and Basmati rice) and a reference food (glucose) on separate occasions. Postprandial blood glucose and plasma insulin concentrations were measured at fasting ( -5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min after food consumption. Using the trapezoidal rule, GR, IR, GI and II values were determined. The GR did not differ between ethnic groups for Jasmine rice and Basmati rice. The IR was consistently higher for Jasmine rice (P=0·002) and Basmati rice (P=0·002) among Asian-Indians, probably due to compensatory hyperinsulinaemia to maintain normoglycaemia. The GI and II of both rice varieties did not differ significantly between ethnicities. The overall mean GI for Jasmine rice and Basmati rice were 91 (sd 21) and 59 (sd 15), respectively. The overall mean II for Jasmine rice was 76 (sd 26) and for Basmati rice was 57 (sd 24). We conclude that the GI values presented for Jasmine rice and Basmati rice were applicable to all three ethnic groups in Singapore. Future studies should include deriving the II for greater clinical utility in the prevention and management of T2DM.

  1. Water balance of rice plots under three different cultivation methods: first season results

    Directory of Open Access Journals (Sweden)

    Enrico Antonio Chiaradia

    2013-09-01

    Full Text Available In the last years rice cultivation methods have been the object of an intense research activity aiming to implement new irrigation methods in addition to traditional flooding, in order to reduce water use. This change has concerned also the traditional paddy-rice territories of the north-west of Italy, where rice has been traditionally cultivated as flooded and where paddy fields are a strong landscape landmark and represent a central feature in the Italian and European network for nature protection. The new techniques introduced in these territories consist in a dry seeding followed by field flooding after about one month (third-fourth leaf, and in a full aerobic cultivation with intermittent irrigations, similarly to standard irrigated crops. This paper presents the results obtained after the first year of a monitoring activity carried out at the Ente Nazionale Risi Experimental Station of Castello d’Agogna-Mortara (PV, Italy, where the main terms of water balance have been measured or estimated during the whole crop season. Because there is a substantial lack of data concerning the water balance related to the new water management techniques, the data are of wide interest despite this study covered only one season. The results here presented show that dry seeding-delayed flooding method required a rather similar amount of water respect to the traditional flooding method (2200 mm and 2491 mm, respectively, whereas the aerobic technique required one order of magnitude less water (298 mm, also due to the very shallow depth of the surface aquifer. Since evapotranspiration was nearly the same for the three methods (578 mm, 555 mm, and 464 mm, respectively for traditional flooded, dry seeding-delayed flooding and aerobic methods, percolation was very high in the case of the two flooded methods and very limited in the case of the aerobic cultivation with intermittent irrigations. These results suggest that, if the aerobic cultivation of rice

  2. Little White Lies: Pericarp Color Provides Insights into the Origins and Evolution of Southeast Asian Weedy Rice.

    Science.gov (United States)

    Cui, Yongxia; Song, Beng Kah; Li, Lin-Feng; Li, Ya-Ling; Huang, Zhongyun; Caicedo, Ana L; Jia, Yulin; Olsen, Kenneth M

    2016-12-07

    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy rice, a multiple-origin model has been proposed based on neutral markers and analyses of domestication genes for hull color and seed shattering. Here, we examined variation in pericarp (bran) color and its molecular basis to address how this trait evolved in Malaysian weeds and its possible role in weed adaptation. Functional alleles of the Rc gene confer proanthocyanidin pigmentation of the pericarp, a trait found in most wild and weedy Oryzas and associated with seed dormancy; nonfunctional rc alleles were strongly favored during rice domestication, and most cultivated varieties have nonpigmented pericarps. Phenotypic characterizations of 52 Malaysian weeds revealed that most strains are characterized by the pigmented pericarp; however, some weeds have white pericarps, suggesting close relationships to cultivated rice. Phylogenetic analyses indicate that the Rc haplotypes present in Malaysian weeds likely have at least three distinct origins: wild O. rufipogon, white-pericarp cultivated rice, and red-pericarp cultivated rice. These diverse origins contribute to high Rc nucleotide diversity in the Malaysian weeds. Comparison of Rc allelic distributions with other rice domestication genes suggests that functional Rc alleles may confer particular fitness benefits in weedy rice populations, for example, by conferring seed dormancy. This may promote functional Rc introgression from local wild Oryza populations. Copyright © 2016 Cui et al.

  3. Genome wide association study (GWAS) for grain yield in rice cultivated under water deficit.

    Science.gov (United States)

    Pantalião, Gabriel Feresin; Narciso, Marcelo; Guimarães, Cléber; Castro, Adriano; Colombari, José Manoel; Breseghello, Flavio; Rodrigues, Luana; Vianello, Rosana Pereira; Borba, Tereza Oliveira; Brondani, Claudio

    2016-12-01

    The identification of rice drought tolerant materials is crucial for the development of best performing cultivars for the upland cultivation system. This study aimed to identify markers and candidate genes associated with drought tolerance by Genome Wide Association Study analysis, in order to develop tools for use in rice breeding programs. This analysis was made with 175 upland rice accessions (Oryza sativa), evaluated in experiments with and without water restriction, and 150,325 SNPs. Thirteen SNP markers associated with yield under drought conditions were identified. Through stepwise regression analysis, eight SNP markers were selected and validated in silico, and when tested by PCR, two out of the eight SNP markers were able to identify a group of rice genotypes with higher productivity under drought. These results are encouraging for deriving markers for the routine analysis of marker assisted selection. From the drought experiment, including the genes inherited in linkage blocks, 50 genes were identified, from which 30 were annotated, and 10 were previously related to drought and/or abiotic stress tolerance, such as the transcription factors WRKY and Apetala2, and protein kinases.

  4. 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

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

    Science.gov (United States)

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

    2009-01-01

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

  6. Decline of traditional rice farming constrains the recovery of the endangered Asian crested ibis (Nipponia nippon).

    Science.gov (United States)

    Sun, Yiwen; Wang, Tiejun; Skidmore, Andrew K; Wang, Qi; Ding, Changqing

    2015-12-01

    Traditional agriculture benefits a rich diversity of plants and animals. The winter-flooded rice fields in the Qinling Mountains, China, are the last refuge for the endangered Asian crested ibis (Nipponia nippon), and intensive efforts have been made to protect this anthropogenic habitat. Analyses of multi-temporal satellite data indicate that winter-flooded rice fields have been continuously reduced across the current range of crested ibis during the past two decades. The rate of loss of these fields in the core-protected areas has unexpectedly increased to a higher level than that in non-protected areas in the past decade. The best fit (R (2) = 0.87) numerical response model of the crested ibis population shows that a reduction of winter-flooded rice fields decreases population growth and predicts that the population growth will be constrained by the decline of traditional winter-flooded rice fields in the coming decades. Our findings suggest that the decline of traditional rice farming is likely to continue to pose a threat to the long-term survival and recovery of the crested ibis population in China.

  7. Effects of seedling age and cultivation density on agronomic characteristics and grain yield of mechanically transplanted rice.

    Science.gov (United States)

    Liu, Qihua; Zhou, Xuebiao; Li, Jingling; Xin, Caiyun

    2017-10-26

    Delayed transplantation frequently occurs in mechanically transplanted rice in China, leading to a significant reduction in grain yield. Thus, determining how to compensate grain yield loss is crucial for improving rice cultivation technology. A field experiment was conducted to investigate the effects of cultivation density and seedling age on agronomic traits and grain yield of mechanically transplanted rice. With increasing seedling age, rice tiller number, pre-anthesis dry matter accumulation, remobilization efficiency and contribution to grain yield, as well as post-anthesis photosynthesis amount decreased, causing reductions in the number of effective panicles, the total number of grains per panicle, the sink capacity per tiller, and grain yield. In rice transplanted at 30- and 35-day seedling ages, increasing cultivation density significantly enhanced the number of effective panicles and grain yield. Additionally, there existed strong, positive correlations between sink capacity per tiller and pre-anthesis dry matter remobilization efficiency and pre-anthesis dry matter contribution to grain yield. We conclude that in addition to cultivation density, enhancing the amount of pre-anthesis dry matter and the remobilization efficiency could be feasible for mitigating grain yield loss caused by delayed transplantation.

  8. Genetic variation for traits associated with domestication identified in a cultivated rice, Nipponbare (Oryza sativa ssp. japonica) x ancestral rice, O. nivara, mapping population

    Science.gov (United States)

    Oryza nivara, the progenitor of cultivated rice, O. sativa, has been the source of novel alleles for resistance to biotic and abiotic stresses, as well as for yield improvement. Many of these alleles were lost during the domestication process. To determine the molecular changes that occurred during ...

  9. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization.

    Science.gov (United States)

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11-4.28 and 4.78-7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52-3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48-4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26-9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield.

  10. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization

    Science.gov (United States)

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11–4.28 and 4.78–7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52–3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48–4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26–9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield. PMID:28174589

  11. To What Extent Do Improved Practices Increase Productivity of Small-Scale Rice Cultivation in A Rain-fed Area? : Evidence from Tanzania

    OpenAIRE

    Yuko Nakano; Yuki Tanaka; Keijiro Otsuka

    2014-01-01

    This paper investigates the impact of training provided by a large-scale private farm on the performance of surrounding small-scale rice farmers in a rain-fed area in Tanzania. We found that the training effectively enhances the adoption of improved rice cultivation practices, paddy yield, and profit of rice cultivation by small-holder farmers. In fact, the trainees achieve paddy yield of 5 tons per hectare on average, which is remarkably high for rain-fed rice cultivation. Our results sugges...

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

    Science.gov (United States)

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

    2006-09-01

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

  13. Phylogeography of the Asian rice gall midge Orseolia oryzae (Wood Mason) (Diptera: Cecidomyiidae) in Thailand.

    Science.gov (United States)

    Janique, Solene; Sriratanasak, Wantana; Ketsuwan, Kulchana; Jairin, Jirapong; Jeratthitikul, Ekgachai

    2017-02-01

    The Asian rice gall midge (RGM) Orseolia oryzae (Wood Mason) (Diptera: Cecidomyiidae) is a major pest of rice, leading to yield losses in Thailand and many Asian countries. Despite an increasing number of reported midge outbreaks and the presence of many susceptible rice varieties, only a few studies have focused on the genetic variation of the midges. Therefore, we analyzed the phylogeography among Thai RGM populations covering north, northeast and central Thailand. Two mitochondrial DNA genes, cytochrome C oxidase I (COI) and 12S, and a non-coding repeat region (RR) situated just before COI were amplified. Overall, the haplotype diversity for COI and 12S genes of the Thai population was high, but the nucleotide diversity was quite low. Altogether, the phylogenetic tree and pairwise F st values indicated that Thai RGM populations recently expanded and were homogeneously distributed throughout the country, except for some populations in the north, which most likely became recently isolated from the main population. Two non-coding repeat motifs, that were recently observed in the mitogenome of RGM in India, were absent in Thai populations and replaced by an 89 bp non-coding sequence. Tandem nucleotide repeats of the sequence TA were also observed. The repeat copy number varied from 2 to 11 and was not correlated with geographical repartition of the midge. Finally, COI barcoding divergence between Indian and Thai populations was high (6.3% in average), giving insights into the potential existence of an RGM species complex in Asia.

  14. The Interactive Effect of Diversification and Farming Scale on Productivity of Family Farm:Taking Rice Cultivation as An Example

    Science.gov (United States)

    Wei, Zhou

    2017-05-01

    Based on the diversification and cultivation scale, the rice cropping data of rural fixed observation points in 2011 were selected and the effect of diversification degree on rice productivity was analyzed by the Tobit model. The empirical results of the model show that diversification of sample farm will lead to loss of rice production efficiency. With the increase of rice planting scale, the loss of rice production efficiency will need to be further increased by diversification. Thus, we should stick to the family farm of specialized production operation. The transfer of land, the price and quantity of leasing, respecting the law of the market; the raising of funds can be considered non-subsidized capital market financing to help, while maintaining a certain degree of diversification, to avoid idle assets, low resource efficiency loss.

  15. Monitoring water fluxes in rice plots under three different cultivation methods

    Directory of Open Access Journals (Sweden)

    Enrico Antonio Chiaradia

    2013-09-01

    Full Text Available Italy is the leading producer of rice in Europe with over half of total production, almost totally concentrated in a large traditional paddy rice area between the Lombardy and Piedmont regions, in the north-western part of the country. In this area irrigation of rice has been traditionally carried out by flooding. The introduction of new combined irrigation and agronomic management practices (dry seeding followed by field flooding and in a full aerobic cultivation with intermittent irrigations, aiming to reduce the water consumption, can determine considerable effect on the landscape and the water cycle. With the aim to study in depth the water fluxes during the whole crop season, three experimental plots at the Ente Nazionale Risi-Rice Research Centre’s Experimental Station of Castello d’Agogna (PV were instrumented. In each plot the following instruments have been installed: 1 a long throated flume and a double shaped (V-notch and rectangular thin plate for superficial inputs and outputs, 3 a set of piezometers for groundwater levels, 4 one stage level gauge in each submerged field, 5 four tensiometers and moisture sensors clusters, 6 one eddy covariance station for vapour fluxes estimation. Most of the instruments were equipped with electrical sensors connected by cables to a wireless data logger that, in turn, send the data to a PC placed within ENR offices and web-connected by a LAN. In this way, besides the automatic download of data, it was possible to remotely control the devices, to quickly fix troubles, and to better plan the field trips. The management of the whole framework was done by a specifically developed software. In this paper the whole system, which presents some degree of innovation, is described in detail.

  16. Rice cultivation in the farming systems of Sukumaland, Tanzania : a quest for sustainable production under structural adjustment programmes

    NARCIS (Netherlands)

    Meertens, H.C.C.

    1999-01-01

    This thesis investigates options for sustainable rice cultivation and general agricultural development in the Mwanza and Shinyanga regions in northwestern Tanzania, often called Sukumaland due to the predominance of Wasukuma people. Generally Sukumaland has a semi-arid climate; agriculture

  17. Molecular analysis of utility of a retrotransposon, p-SINE1-r2 in the Asian wild rice and weedy rice populations.

    Science.gov (United States)

    Prathepha, Preecha

    2009-02-01

    The distribution of a retrotransposon, p-SINE1-r2 located at the waxy locus was analyzed by the PCR assay in the perennial wild rice (Oryza rufipogon) which inhabited in four isolated and six disturbed populations and in the weedy rice population. The level of clonality of the wild rice species was determined in populations subject to level of water supply and another disturbance. The results showed that all four isolated populations carried the genotype (-/-) and (-/+), while three genotypes (-/-), (-/+) and (+/+) was found on the six populations which grown near by rice fields. This finding was strongly supported the idea that the original wild rice populations of O. rufipogon exhibited prominent genotype (-/-) and (-/+) and mainly propagated by vegetative reproduction and the allele (+) which found in the wild rice plant with the genotype (+/+) may originated from gene flow from cultivated rice to wild rice. Weedy rice accessions used in this study showed the three genotypes based on this DNA locus. The distribution of this DNA locus in wild rice and weedy rice populations were deviated from the Hardy-Weinberg equilibrium. The perennial wild rice populations were annually under season drought (March to May of the year in Thailand, Laos and Cambodia), they tended to have small size clones with relatively high clonal diversity (i.e., number of genotypes), except for the population from Cambodia, which carried only the genotype (-/+). Although DNA maker used to detect genetic variation at population levels is too small, but this locus is very sensitive enough to be a useful indicator for genetic variation at the population level.

  18. Beneficial effect of compost utilization on reducing greenhouse gas emissions in a rice cultivation system through the overall management chain.

    Science.gov (United States)

    Jeong, Seung Tak; Kim, Gil Won; Hwang, Hyun Young; Kim, Pil Joo; Kim, Sang Yoon

    2018-02-01

    Livestock manure application can stimulate greenhouse gas (GHG) emissions, especially methane (CH4) in rice paddy. The stabilized organic matter (OM) is recommended to suppress CH4 emission without counting the additional GHG emission during the composting process. To evaluate the effect of compost utilization on the net global warming potential (GWP) of a rice cropping system, the fluxes of GHGs from composting to land application were calculated by a life cycle assessment (LCA) method. The model framework was composed of GHG fluxes from industrial activities and biogenic GHG fluxes from the composting and rice cultivation processes. Fresh manure emitted 30MgCO2-eq.ha-1, 90% and 10% of which were contributed by CH4 and nitrous oxide (N2O) fluxes, respectively, during rice cultivation. Compost utilization decreased net GWP by 25% over that of the fresh manure during the whole process. The composting process increased the GWP of the industrial processes by 35%, but the 60% reduction in CH4 emissions from the rice paddy mainly influenced the reduction of GWP during the overall process. Therefore, compost application could be a good management strategy to reduce GHG emissions from rice paddy systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Allele Distributions at Hybrid Incompatibility Loci Facilitate the Potential for Gene Flow between Cultivated and Weedy Rice in the US

    Science.gov (United States)

    Craig, Stephanie M.; Reagon, Michael; Resnick, Lauren E.; Caicedo, Ana L.

    2014-01-01

    The accumulation of independent mutations over time in two populations often leads to reproductive isolation. Reproductive isolation between diverging populations may be reinforced by barriers that occur either pre- or postzygotically. Hybrid sterility is the most common form of postzygotic isolation in plants. Four postzygotic sterility loci, comprising three hybrid sterility systems (Sa, s5, DPL), have been recently identified in Oryza sativa. These loci explain, in part, the limited hybridization that occurs between the domesticated cultivated rice varieties, O. sativa spp. japonica and O. sativa spp. indica. In the United States, cultivated fields of japonica rice are often invaded by conspecific weeds that have been shown to be of indica origin. Crop-weed hybrids have been identified in crop fields, but at low frequencies. Here we examined the possible role of these hybrid incompatibility loci in the interaction between cultivated and weedy rice. We identified a novel allele at Sa that seemingly prevents loss of fertility in hybrids. Additionally, we found wide-compatibility type alleles at strikingly high frequencies at the Sa and s5 loci in weed groups, and a general lack of incompatible alleles between crops and weeds at the DPL loci. Our results suggest that weedy individuals, particularly those of the SH and BRH groups, should be able to freely hybridize with the local japonica crop, and that prezygotic factors, such as differences in flowering time, have been more important in limiting weed-crop gene flow in the past. As the selective landscape for weedy rice changes due to increased use of herbicide resistant strains of cultivated rice, the genetic barriers that hinder indica-japonica hybridization cannot be counted on to limit the flow of favorable crop genes into weeds. PMID:24489758

  20. Allele distributions at hybrid incompatibility loci facilitate the potential for gene flow between cultivated and weedy rice in the US.

    Directory of Open Access Journals (Sweden)

    Stephanie M Craig

    Full Text Available The accumulation of independent mutations over time in two populations often leads to reproductive isolation. Reproductive isolation between diverging populations may be reinforced by barriers that occur either pre- or postzygotically. Hybrid sterility is the most common form of postzygotic isolation in plants. Four postzygotic sterility loci, comprising three hybrid sterility systems (Sa, s5, DPL, have been recently identified in Oryza sativa. These loci explain, in part, the limited hybridization that occurs between the domesticated cultivated rice varieties, O. sativa spp. japonica and O. sativa spp. indica. In the United States, cultivated fields of japonica rice are often invaded by conspecific weeds that have been shown to be of indica origin. Crop-weed hybrids have been identified in crop fields, but at low frequencies. Here we examined the possible role of these hybrid incompatibility loci in the interaction between cultivated and weedy rice. We identified a novel allele at Sa that seemingly prevents loss of fertility in hybrids. Additionally, we found wide-compatibility type alleles at strikingly high frequencies at the Sa and s5 loci in weed groups, and a general lack of incompatible alleles between crops and weeds at the DPL loci. Our results suggest that weedy individuals, particularly those of the SH and BRH groups, should be able to freely hybridize with the local japonica crop, and that prezygotic factors, such as differences in flowering time, have been more important in limiting weed-crop gene flow in the past. As the selective landscape for weedy rice changes due to increased use of herbicide resistant strains of cultivated rice, the genetic barriers that hinder indica-japonica hybridization cannot be counted on to limit the flow of favorable crop genes into weeds.

  1. Genetic diversity among salt-tolerant rice (Oryza sativa L. landraces cultivated in the coastal districts of Bangladesh

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    AKKAS ALI

    2014-04-01

    Full Text Available The aim of this study was to determine genetic diversity and relationships among the salt-tolerant rice landraces cultivated in the coastal districts of Bangladesh. DNA extracted from seedlings of nine salt-tolerant local rice landraces and three established salt-tolerant rice varieties was subjected to random amplified polymorphic DNA (RAPD analysis using a number of random decamer primers. Polymorphic bands generated with five primers were scored and used for determining polymorphic information contents (PIC and in deriving a dendrogram using the Jaccard similarity coefficient-based unweighted pair-group method with arithmetic means (UPGMA. The five primers generated 84 reproducible bands of the size range 0.24-1.90 kbp and 73% of the bands were polymorphic. The UPGMA dendrogram showed five major clusters at genetic similarity of 0.55. The PIC values ranged from 0.71 to 0.90 with an average of 0.85. The pair-wise similarity index values ranged 28.8-97.1% among the twelve genotypes. The three established rice verities formed a single cluster and the local landraces formed four clusters. Our result revealed high level of genetic diversity among the local rice landraces. The RAPD markers identified could be useful in developing high-yield salt-tolerant rice strains with improved grain quality.

  2. Identification of mildew resistance in wild and cultivated Central Asian grape germplasm

    Science.gov (United States)

    2013-01-01

    Background Cultivated grapevines, Vitis vinifera subsp. sativa, evolved from their wild relative, V. vinifera subsp. sylvestris. They were domesticated in Central Asia in the absence of the powdery mildew fungus, Erysiphe necator, which is thought to have originated in North America. However, powdery mildew resistance has previously been discovered in two Central Asian cultivars and in Chinese Vitis species. Results A set of 380 unique genotypes were evaluated with data generated from 34 simple sequence repeat (SSR) markers. The set included 306 V. vinifera cultivars, 40 accessions of V. vinifera subsp. sylvestris, and 34 accessions of Vitis species from northern Pakistan, Afghanistan and China. Based on the presence of four SSR alleles previously identified as linked to the powdery mildew resistance locus, Ren1, 10 new mildew resistant genotypes were identified in the test set: eight were V. vinifera cultivars and two were V. vinifera subsp. sylvestris based on flower and seed morphology. Sequence comparison of a 620 bp region that includes the Ren1-linked allele (143 bp) of the co-segregating SSR marker SC8-0071-014, revealed that the ten newly identified genotypes have sequences that are essentially identical to the previously identified mildew resistant V. vinifera cultivars: ‘Kishmish vatkana’ and ‘Karadzhandal’. Kinship analysis determined that three of the newly identified powdery mildew resistant accessions had a relationship with ‘Kishmish vatkana’ and ‘Karadzhandal’, and that six were not related to any other accession in this study set. Clustering procedures assigned accessions into three groups: 1) Chinese species; 2) a mixed group of cultivated and wild V. vinifera; and 3) table grape cultivars, including nine of the powdery mildew resistant accessions. Gene flow was detected among the groups. Conclusions This study provides evidence that powdery mildew resistance is present in V. vinifera subsp. sylvestris, the dioecious wild

  3. Malaysian water footprint accounts: Blue and green water footprint of rice cultivation and the impact of water consumption in Malaysia

    Science.gov (United States)

    Fadillah, M. G. Nor; Marlia, M. H.

    2016-11-01

    Following water footprint approach, this study estimates the blue and green water consumption of rice cultivation in 11 states located in Peninsular Malaysia. The latter part evaluates the potential of water deprivation for freshwater resources in Malaysia. Climate data such as rainfall, temperature, humidity, sunshine and wind speed were used to calculate evapotranspiration rate and crop water use. The water footprint for cultivating rice was estimated for both main and off seasons range between 1600 m3/ton to 3300 m3/ton. The result of this study showed that the green water footprint is higher compared to the blue water footprint for both seasons. In conclusion, the potential water deprivation can be determined by integrating the water footprint and water stress index of different watersheds of Malaysia.

  4. Soil concentration of glyphosate and AMPA under rice cultivation with contrasting levels of fertilization

    Science.gov (United States)

    Rey Montoya, Tania; Micaela Biassoni, María; Graciela Herber, Luciana; De Geronimo, Eduardo; Aparicio, Virginia

    2017-04-01

    Rice (Oryza sativa) is the world's most important crop species and occupies c. 150 mill ha. The province of Corrientes in Argentina leads the national production of rice cultivation. Glyphosate is a non-selective herbicide commonly used to control weeds. The molecule is inactivated once applied due to its adsorption in the soil, and once desorbed is degraded by soil microflora resulting in sarcosine and aminomethylphosphoric acid (AMPA) molecules. The objective of this investigation was to compare glyphosate and AMPA concentration in soil under different levels of fertilization along the growth season of the rice crop. A field experiment following a completely randomized design was carried out with four replicates. We evaluated four levels of fertilization (0-18-40): Control: 0 kg ha-1, Dose 1: 120 kg ha-1, Dose 2: 150 kg ha-1, Dose 3: 180 kg ha-1; and two levels of Glyphosate: with (Gly) or without (No) application. Four sampling moments were defined: pre-sowing (taken as reference), vegetative stage (V4, 30 days after application), in floral primordial differentiation-DPF (80 days post-application), and at physiological maturity-MF (125 days after application). Flooding was applied in V4 after sampling. The method used for determination and quantification was by ultra high-pressure liquid chromatography coupled to ESI UHPLC-MS / MS tandem mass spectrometer (+/-) (Acquit-Quattro Premier). We found that glyphosate and AMPA varied their concentration in soil according to the time of sampling. Detected levels of both molecules at pre-sowing indicate the persistence of this herbicide from earlier crop seasons. The highest concentration was measured in MF followed by V4. Interestingly, AMPA concentration showed higher values in V4 without application compared to the treatment with glyphosate application. On the other hand, in flooded soil both molecules presented a decrease in their concentration probably because of their dilution in water, increasing it again after

  5. Rice Cultivation under the Different Irrigation Systems in Nong Wai Pioneer Agriculture Project Area of Khon Kaen, Thailand

    OpenAIRE

    Wasano, Kikuo; Thanutong, Porntip; Tsuchiya, Keizo

    1987-01-01

    Field surveys of rice cultivation and hearing investigation of the farm managements were conducted in 1985 at the three villages of Khon Kaen in North-Eastern Thailand, for clarifying the effectiveness of the irrigation projects conducted and also for comparing the superiority of two different irrigation systems adopted at the areas from agronomical and economical viewpoints. The irrigation systems, both intensive (accompanied by land consolidation) and extensive (with only irrigation canal),...

  6. Systems Dynamics Modelling Identifies (Un)Sustainable Rice Cultivation Strategies for the Mekong Delta Under Upstream Hydropower Development

    Science.gov (United States)

    Darby, S. E.; Chapman, A.; Hackney, C. R.; Leyland, J.; Parsons, D. R.; Aalto, R. E.; Nicholas, A. P.; Best, J.

    2016-12-01

    The Vietnamese Mekong delta is one of the world's largest rice producing regions, but it is facing a major sustainability challenge. The delta is being `drowned' by rising relative sea-levels, a situation that is being exacerbated by a reduction in the supply of rivers sediments due to a combination of climate change and sediment trapping linked to the construction of large hydropower dams in upstream countries. Poverty is prevalent and farmers face many challenges, such as declining productivity, income insecurity and debt; they are therefore reliant on natural ecosystem services, notably soil nutrient replenishment by sediment deposition during floods, to minimise dependence on chemical fertilisers. Meanwhile, the drive to intensify rice production (a key national policy goal that has underpinned the region's recent economic development) has been achieved by replacing the traditional use of `low' (0-2m in height) dyke networks with `high' (>3.5m) dyke networks. Since rice production takes place within these dyke rings, this has enabled a switch from traditional cultivation techniques (double cropping within low dyke rings) to a new system of triple cropping (in which an extra crop can be grown due to the exclusion of flood waters during the monsoon season) within the high dykes. This involves trading off immediate benefits (protection against floods; improved rice production) against long term disadvantages (the exclusion of sediment accelerates relative sea-level rise, adding to flood risk in the long term, while sediment borne nutrients are key to agricultural productivity in the long term). Here we use systems dynamics modelling to demonstrate that current rice cultivation strategies are a maladaptation which, under a future of declining sediment loads due to upstream hydropower development, are not sustainable in the long term and present recommendations for more sustainable water management policies in the delta's rice growing region.

  7. Isolation and Characterization of Microsatellite Loci in the Asian Rice Gall Midge (Orseolia oryzae (Diptera: Cecidomyiidae

    Directory of Open Access Journals (Sweden)

    Charagonda Revathy

    2011-01-01

    Full Text Available Microsatellite loci were isolated from the genomic DNA of the Asian rice gall midge, Orseolia oryzae (Wood-Mason using a hybridization capture approach. A total of 90 non-redundant primer pairs, representing unique loci, were designed. These simple sequence repeat (SSR markers represented di (72%, tri (15.3%, and complex repeats (12.7%. Three biotypes of gall midge (20 individuals for each biotype were screened using these SSRs. The results revealed that 15 loci were hyper variable and showed polymorphism among different biotypes of this pest. The number of alleles ranged from two to 11 and expected heterozygosity was above 0.5. Inheritance studies with three markers (observed to be polymorphic between sexes revealed sex linked inheritance of two SSRs (Oosat55 and Oosat59 and autosomal inheritance of one marker (Oosat43. These markers will prove to be a useful tool to devise strategies for integrated pest management and in the study of biotype evolution in this important rice pest.

  8. Microbial activity promoted with organic carbon accumulation in macroaggregates of paddy soils under long-term rice cultivation

    Science.gov (United States)

    Liu, Yalong; Wang, Ping; Ding, Yuanjun; Lu, Haifei; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Filley, Timothy; Zhang, Xuhui; Zheng, Jinwei; Pan, Genxing

    2016-12-01

    While soil organic carbon (SOC) accumulation and stabilization has been increasingly the focus of ecosystem properties, how it could be linked to soil biological activity enhancement has been poorly assessed. In this study, topsoil samples were collected from a series of rice soils shifted from salt marshes for 0, 50, 100, 300 and 700 years from a coastal area of eastern China. Soil aggregates were fractioned into different sizes of coarse sand (200-2000 µm), fine sand (20-200 µm), silt (2-20 µm) and clay (properties were determined to investigate niche specialization of different soil particle fractions in response to long-term rice cultivation, including recalcitrant and labile organic carbon, microbial diversity of bacterial, archaeal and fungal communities, soil respiration and enzyme activity. The results showed that the mass proportion both of coarse-sand (2000-200 µm) and clay (< 2 µm) fractions increased with prolonged rice cultivation, but the aggregate size fractions were dominated by fine-sand (200-20 µm) and silt (20-2 µm) fractions across the chronosequence. SOC was highly enriched in coarse-sand fractions (40-60 g kg-1) and moderately in clay fractions (20-25 g kg-1), but was depleted in silt fractions (˜ 10 g kg-1). The recalcitrant carbon pool was higher (33-40 % of SOC) in both coarse-sand and clay fractions than in fine-sand and silt fractions (20-29 % of SOC). However, the ratio of labile organic carbon (LOC) to SOC showed a weakly decreasing trend with decreasing size of aggregate fractions. Total soil DNA (deoxyribonucleic acid) content in the size fractions followed a similar trend to that of SOC. Despite the largely similar diversity between the fractions, 16S ribosomal gene abundance of bacteria and of archaeal were concentrated in both coarse-sand and clay fractions. Being the highest generally in coarse-sand fractions, 18S rRNA gene abundance of fungi decreased sharply but the diversity gently, with decreasing size of the aggregate

  9. Pyrosequencing-Based Transcriptome Analysis of the Asian Rice Gall Midge Reveals Differential Response during Compatible and Incompatible Interaction

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    Jagadish S. Bentur

    2012-10-01

    Full Text Available The Asian rice gall midge (Orseolia oryzae is a major pest responsible for immense loss in rice productivity. Currently, very little knowledge exists with regard to this insect at the molecular level. The present study was initiated with the aim of developing molecular resources as well as identifying alterations at the transcriptome level in the gall midge maggots that are in a compatible (SH or in an incompatible interaction (RH with their rice host. Roche 454 pyrosequencing strategy was used to develop both transcriptomics and genomics resources that led to the identification of 79,028 and 85,395 EST sequences from gall midge biotype 4 (GMB4 maggots feeding on a susceptible and resistant rice variety, TN1 (SH and Suraksha (RH, respectively. Comparative transcriptome analysis of the maggots in SH and RH revealed over-representation of transcripts from proteolysis and protein phosphorylation in maggots from RH. In contrast, over-representation of transcripts for translation, regulation of transcription and transcripts involved in electron transport chain were observed in maggots from SH. This investigation, besides unveiling various mechanisms underlying insect-plant interactions, will also lead to a better understanding of strategies adopted by insects in general, and the Asian rice gall midge in particular, to overcome host defense.

  10. Cultivation of different strains of king oyster mushroom (Pleurotus eryngii) on saw dust and rice straw in Bangladesh.

    Science.gov (United States)

    Moonmoon, Mahbuba; Uddin, Md Nazim; Ahmed, Saleh; Shelly, Nasrat Jahan; Khan, Md Asaduzzaman

    2010-10-01

    Pleurotus eryngii is a popular mushroom due to its excellent consistency of cap and stem, culinary qualities and longer shelf life. In Bangladesh, where Pleurotus mushrooms are very popular, P. eryngii may take position among the consumers, but currently this mushroom is not cultivated in large scale there. In this study, 3 strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (germplasm collected from China) and Pe-3 (germplasm collected from Japan) were cultivated on saw dust and rice straw and their growth and yield parameters were investigated. Pe-1 on saw dust showed the highest biological yield and efficiency (73.5%) than other strains. Also, the mycelium run rate and number of fruiting bodies were higher in Pe-1 than other two strains. The quality of mushroom strains was near about similar. On saw dust, the yield and efficiency were better than those cultivated on rice straw, however, on straw; the mushroom fruiting bodies were larger in size. This study shows the prospects of P. eryngii cultivation in Bangladesh and suggests further study in controlled environment for higher yield and production.

  11. 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.

  12. Increasing Efficiency of Soil Fertility Map for Rice Cultivation Using Fuzzy Logic, AHP and GIS

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    javad seyedmohammadi

    2017-02-01

    fertility groups for better management of soil and plant nutrition. Weight of soil parameters was0.54, 0.29 and 0.17 for organic carbon, available phosphor and potassium, respectively. Fuzzy map of study area includes five soil fertility groups as: 22.9% very high fertility, 27.7% high fertility, 35.53% medium fertility, 10.48% low fertility and 3.39% very low fertility. Consequently, a separated map for soil fertility prepared to evaluate soil fertility of study area for rice cultivation. Toinvestigatethe efficiency of fuzzy model and AHP in increasing the accuracy of soil fertility map, soil fertility map with Boolean method prepared as well. Boolean map showed 58.88% fertile and 41.12% unfertile.15 soil samples from different soil fertility groups of study area were derived fromcontrol of maps accuracy. 13 renewed samples of 15 and 9 soil samples have matched with fuzzy and Boolean map, respectively. Comparison of parameters mean in fuzzy map fertility groups showed that parameters mean amounts of very high and high fertility groups are higher than optimum level except potassium that is a few lower than optimum level in high fertility group, therefore, addition of fertilizers in these groups could not be useful to increase rice crop production. Phosphorus parameter amount is lower than the critical level in very low, low and medium fertility groups, then in these groups phosphorus fertilizer should be added to the soil toincreaserice production. The amount of potassium parameter is higher than the critical level and lower than optimum limit in very low, low, medium and high fertility groups, then in these groups addition of potassium fertilizer will results in theincrease of production. Organic carbon amount is lower than optimum level in very low and low fertility groups. With regard to the relation between organic carbon andnitrogen and phosphorus, therefore, the addition of organic carbon fertilizer could compensate deficit of nitrogen and phosphorus in these groups

  13. Aflatoxin B1 degradation during co-cultivation of Aspergillus flavus and Pleurotus ostreatus strains on rice straw.

    Science.gov (United States)

    Das, Arijit; Bhattacharya, Sourav; Palaniswamy, Muthusamy; Angayarkanni, Jayaraman

    2015-06-01

    Aflatoxin B1 (AFB1) produced by Aspergillus flavus is known to have carcinogenic and teratogenic effects on animal health. Accidental feeding of AFB1-contaminated rice straw may be detrimental to dairy cattle. White-rot basidiomycetous fungus Pleurotus ostreatus can grow on different agronomic wastes by synthesizing different ligninolytic enzymes. These extracellular enzymes are capable of degrading many environmentally hazardous compounds including AFB1. The present study examines the ability of different strains of P. ostreatus to degrade AFB1 in contaminated rice straw. Different strains of A. flavus were inoculated on rice straw for AFB1 production. The moldy straw was then subjected to co-cultivation by different strains of P. ostreatus. The extent of AFB1 degradation was determined by high performance liquid chromatography. Results indicated the presence of AFB1 in the moldy straw samples at levels of 27.95 ± 0.23 and 21.26 ± 0.55 µg/g of dry substrate for A. flavus MTCC 2798 and A. flavus GHBF09, respectively. Co-cultivation of P. ostreatus strains on AFB1-contaminated rice straw revealed their ability to rapidly colonize the substrate by profuse hyphal ramification. Highest degradation of AFB1 (89.41 %) was recorded in the straw containing co-cultures of A. flavus MTCC 2798 and P. ostreatus GHBBF10. Natural isolate P. ostreatus GHBBF10 demonstrated higher AFB1-degradation potential than P.ostreatus MTCC 142. This basidiomycete strain can be further exploited to effectively degrade moderate concentrations of AFB1 in contaminated moldy rice straw.

  14. Managing Water and Soils to Achieve Adaptation and Reduce Methane Emissions and Arsenic Contamination in Asian Rice Production

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    Dennis Wichelns

    2016-04-01

    Full Text Available Rice production is susceptible to damage from the changes in temperature and rainfall patterns, and in the frequency of major storm events that will accompany climate change. Deltaic areas, in which millions of farmers cultivate from one to three crops of rice per year, are susceptible also to the impacts of a rising sea level, submergence during major storm events, and saline intrusion into groundwater and surface water resources. In this paper, I review the current state of knowledge regarding the potential impacts of climate change on rice production and I describe adaptation measures that involve soil and water management. In many areas, farmers will need to modify crop choices, crop calendars, and soil and water management practices as they adapt to climate change. Adaptation measures at the local, regional, and international levels also will be helpful in moderating the potential impacts of climate change on aggregate rice production and on household food security in many countries. Some of the changes in soil and water management and other production practices that will be implemented in response to climate change also will reduce methane generation and release from rice fields. Some of the measures also will reduce the uptake of arsenic in rice plants, thus addressing an important public health issue in portions of South and Southeast Asia. Where feasible, replacing continuously flooded rice production with some form of aerobic rice production, will contribute to achieving adaptation objectives, while also reducing global warming potential and minimizing the risk of negative health impacts due to consumption of arsenic contaminated rice.

  15. Interactions between the oomycete Pythium arrhenomanes and the rice root-knot nematode Meloidogyne graminicola in aerobic Asian rice varieties.

    Science.gov (United States)

    Verbeek, R E M; Banaay, C G B; Sikder, M; De Waele, D; Vera Cruz, C M; Gheysen, G; Höfte, M; Kyndt, Tina

    2016-12-01

    Aerobic rice fields are frequently infested by pathogenic oomycetes (Pythium spp.) and the rice root-knot nematode Meloidogyne graminicola. Here, the interaction between Pythium arrhenomanes and Meloidogyne graminicola was studied in rice roots of two aerobic rice varieties. In different experimental set-ups and infection regimes, plant growth, rice yield, Pythium colonization, as well as establishment, development and reproduction of M. graminicola were studied. In this study, it is shown that the presence of P. arrhenomanes delays the establishment, development and reproduction of M. graminicola compared to single nematode infected plants. The delay in establishment and development of M. graminicola becomes stronger with higher P. arrhenomanes infection pressure. Our data indicate that P. arrhenomanes antagonizes M. graminicola in the rice root and that the plant benefits from this antagonism as shown by the yield data, especially when either of the pathogens is present in high levels.

  16. Responses of water mite assemblages (Acari to environmental parameters at irrigated rice cultivation fields and native lakes

    Directory of Open Access Journals (Sweden)

    Guilherme L. da Silva

    2017-10-01

    Full Text Available ABSTRACT Many studies have revealed that water mite communities can be affected by the physical and chemical parameters of the water. The similarity between the water ‘mite assemblages in local water bodies and in irrigated rice areas can be a way to measure the water conditions, enabling an assessment of the anthropic impact in the environment. The aim of this study was to evaluate the distribution of water mites in lakes and irrigated rice fields in south Brazil. To accomplish that we characterized the distinctive environments using physical and chemical variables such as pH, turbidity (NTU, water temperature (°C and dissolved oxygen (mg/L, in order to verify the influence of these abiotic factors on the species composition of water mite communities; and to compare water mite abundance, richness and composition among different habitats. We assessed three native lakes and four sites with irrigated rice cultivation. Our results showed, for the first time in Brazil, strong correlations between the water mite fauna and turbidity. In addition, native lakes were richer and had greater mite abundance when compared with the irrigated rice areas.

  17. Effects of cultivation of OsrHSA transgenic rice on functional diversity of microbial communities in the soil rhizosphere

    Directory of Open Access Journals (Sweden)

    Xiaobing Zhang

    2015-04-01

    Full Text Available With the widespread cultivation of transgenic crops, there is increasing concern about unintended effects of these crops on soil environmental quality. In this study, we used the Biolog method and ELISA to evaluate the possible effects of OsrHSA transgenic rice on soil microbial utilization of carbon substrates under field conditions. There were no significant differences in average well-color development (AWCD values, Shannon–Wiener diversity index (H, Simpson dominance indices (D and Shannon–Wiener evenness indices (E of microbial communities in rhizosphere soils at eight samplings between OsrHSA transgenic rice and its non-transgenic counterpart. The main carbon sources utilized by soil microbes were carbohydrates, carboxylic acids, amino acids and polymers. The types, capacities and patterns of carbon source utilization by microbial communities in rhizosphere soils were similar throughout the detection period. We detected no OsrHSA protein in the roots of OsrHSA transgenic rice. We concluded that OsrHSA transgenic rice and the rHSA protein it produced did not alter the functional diversity of microbial communities in the rhizosphere.

  18. Organoleptic qualities and acceptability of fortified rice in two Southeast Asian countries

    DEFF Research Database (Denmark)

    Khanh Van, Tran; Burja, Kurt; Thuy Nga, Tran

    2014-01-01

    fortified rice (P rice was found to be highly acceptable in both countries. In Cambodia, schoolchildren consuming fortified rice had higher intakes than when consuming conventional rice (176 g/child/day and 168 g/child/day, respectively; P ...Fortified rice has the potential to improve the micronutrients status of vulnerable populations. However, fortified rice has to have acceptable organoleptic--the sensory properties of a particular food--qualities. Few data exist on the acceptability of fortified rice in Asia. To assess...... the acceptability of two types of fortified rice (cold and hot extruded) in Vietnam and Cambodia, triangle tests were conducted in Vietnam (53 women) and Cambodia (258 adults), testing fortified rice against conventional rice, with participants being asked to score the organoleptic qualities. In addition, Cambodian...

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Caroline Borges Bevilacqua

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

  1. Spatio-temporal variations in the areas suitable for the cultivation of rice and maize in China under future climate scenarios.

    Science.gov (United States)

    Zhang, Yajie; Wang, Yanfen; Niu, Haishan

    2017-12-01

    Predictions of changes in the distribution of areas suitable for the cultivation of rice and maize in China under future climate change scenarios may provide scientific support for the optimization of crop production and measures to mitigate climate change. We conducted a spatial grid-based analysis using projections of future climate generated by the National Center for Atmospheric Research Community Climate System Model version 4 for two representative concentration pathway scenarios (RCP2.6 and RCP8.5), adopted by the fifth phase of the Coupled Model Intercomparison Project to study the areas suitable for the cultivation of rice and maize in China. We investigated the migration of the centers of gravity of the cultivation areas based on climatic and hydrological factors from 2021 to 2100. The results indicated that, under RCP2.6, the areas suitable for the cultivation of rice were located throughout China, except for on the Qinghai-Tibetan Plateau, while the areas suitable for the cultivation of maize were located in northern, southwestern, central, eastern, parts of northeastern and some northern parts of western China. The distributions of both crops under RCP2.6 showed little change over time. In contrast, the areas suitable for the cultivation of rice and maize under RCP8.5 shifted northward and expanded from northwestern to northern China, as a result of greater warming in northern China and the faster warming trend under RCP8.5. This scenario would require much stronger climate mitigation policies to maintain the stable development of agriculture and to slow down the future migration of crop cultivation areas in China. The distribution of areas suitable for the cultivation of rice and maize should be studied further to design appropriate adaptation strategies for dealing with future climate change. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Ayoade, Modupe Alake

    2017-08-01

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

  3. Research Advances in High-Yielding Cultivation and Physiology of Super Rice

    Directory of Open Access Journals (Sweden)

    Jing FU

    2012-09-01

    Full Text Available In 1996, China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types. Today, approximately 80 super rice varieties have been released and some of them show high grain yields of 12–21 t/hm2 in field experiments. The main reasons for the high yields of super rice varieties, compared with those of conventional varieties, can be summarized as follows: more spikelets per panicle and larger sink size (number of spikelets per square meter; larger leaf area index, longer duration of green leaf, greater photosynthetic rate, higher lodging resistance, greater dry matter accumulation before the heading stage, greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period; and larger root system and greater root activity. However, there are two main problems in super rice production: poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets, and low and unstable seed-setting rate. Here, we review recent research advances in the crop physiology of super rice, focusing on biological features, formation of yield components, and population quality. Finally, we suggest further research on crop physiology of super rice.

  4. Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

    Directory of Open Access Journals (Sweden)

    Y.V. SINGH

    2013-03-01

    Full Text Available The system of rice intensification (SRI is reported to have advantages like lower seed requirement, less pest attack, shorter crop duration, higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation. With this background, SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute, New Delhi, India during two wet seasons (2009–2011. In the experiment laid out in a factorial randomized block design, two methods of rice cultivation [conventional transplanting (CT and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44 were used under seven crop nutrition treatments, viz. T1, 120 kg/hm2 N, 26.2 kg/hm2 P and 33 kg/hm2 K; T2, 20 t/hm2 farmyard manure (FYM; T3, 10 t/hm2 FYM + 60 kg/hm2 N; T4, 5 t/hm2 FYM + 90 kg/hm2 N; T5, 5 t/hm2 FYM + 60 kg/hm2 N + 1.5 kg/hm2 blue green algae (BGA; T6, 5 t/hm2 FYM + 60 kg/hm2 N + 1.0 t/hm2 Azolla, and T7, N0P0K0 (control, no NPK application to study the effect on seed quality, yield and water use. In SRI, soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2–3 cm was maintained during the reproductive phase of rice, however, in CT, standing water was maintained in crop growing season. Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI. Seed quality was superior in SRI as compared to CT. Integrated nutrient management (INM resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties. Grain yield attributes such as number of effective tillers per hill, panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone. Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer. The grain yield

  5. The impact of Rhizopus oryzae cultivation on rice bran: Gamma-oryzanol recovery and its antioxidant properties.

    Science.gov (United States)

    Massarolo, Kelly Cristina; Denardi de Souza, Taiana; Collazzo, Carolina Carvalho; Badiale Furlong, Eliana; Souza Soares, Leonor Almeida de

    2017-08-01

    This study evaluated the effect of the solid state cultivation (SSC) time of rice bran by Rhizopus oryzae on γ-oryzanol recovery and its antioxidant properties. Gamma-oryzanol was extracted with organic solvents and its extracts were characterized by GC-FID and HPLC-UV. The antioxidant capacity was assessed by DPPH and ABTS + assays, β-carotene/linoleic acid system, and reduction of oxidation in lipid system. The biomass showed the γ-oryzanol recovery increased by 51.5% (20.52mg/g), and 5.7% in polyunsaturated fatty acids. The γ-oryzanol major components changing in their profile. The γ-oryzanol extract from biomass (72h) showed the greatest DPPH inhibition (59.0%), while 90.5% inhibition of oxidation of β-carotene/linoleic acid system, and 30% reduction of the indicators of oxidation in olive oil was observed in the one cultivated at 96h, these behaviors were confirmed by PCA analyses. SSC provides an increase in the γ-oryzanol recovery followed by improving of the functional properties of rice bran. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-06-08

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

  7. Rice Cultivation and Greenhouse Gas Emissions: A Review and Conceptual Framework with Reference to Ghana

    Directory of Open Access Journals (Sweden)

    Kofi K. Boateng

    2017-01-01

    Full Text Available Rice is an essential crop in Ghana. Several aspects of rice have been studied to increase its production; however, the environmental aspects, including impact on climate change, have not been studied well. There is therefore a gap in knowledge, and hence the need for continuous research. By accessing academic portals, such as Springer Open, InTech Open, Elsevier, and the Kwame Nkrumah University of Science and Technology’s offline campus library, 61 academic publications including peer reviewed journals, books, working papers, reports, etc. were critically reviewed. It was found that there is a lack of data on how paddy rice production systems affect greenhouse gas (GHG emissions, particularly emissions estimation, geographical location, and crops. Regarding GHG emission estimation, the review identified the use of emission factors calibrated using temperate conditions which do not suit tropical conditions. On location, most research on rice GHG emissions have been carried out in Asia with little input from Africa. In regard to crops, there is paucity of in-situ emissions data from paddy fields in Ghana. Drawing on the review, a conceptual framework is developed using Ghana as reference point to guide the discussion on fertilizer application, water management rice cultivars, and soil for future development of adaptation strategies for rice emission reduction.

  8. Serine Proteases-Like Genes in the Asian Rice Gall Midge Show Differential Expression in Compatible and Incompatible Interactions with Rice

    Directory of Open Access Journals (Sweden)

    Suresh Nair

    2011-04-01

    Full Text Available The Asian rice gall midge, Orseolia oryzae (Wood-Mason, is a serious pest of rice. Investigations into the gall midge-rice interaction will unveil the underlying molecular mechanisms which, in turn, can be used as a tool to assist in developing suitable integrated pest management strategies. The insect gut is known to be involved in various physiological and biological processes including digestion, detoxification and interaction with the host. We have cloned and identified two genes, OoprotI and OoprotII, homologous to serine proteases with the conserved His87, Asp136 and Ser241 residues. OoProtI shared 52.26% identity with mosquito-type trypsin from Hessian fly whereas OoProtII showed 52.49% identity to complement component activated C1s from the Hessian fly. Quantitative real time PCR analysis revealed that both the genes were significantly upregulated in larvae feeding on resistant cultivar than in those feeding on susceptible cultivar. These results provide an opportunity to understand the gut physiology of the insect under compatible or incompatible interactions with the host. Phylogenetic analysis grouped these genes in the clade containing proteases of phytophagous insects away from hematophagous insects.

  9. Serine proteases-like genes in the asian rice gall midge show differential expression in compatible and incompatible interactions with rice.

    Science.gov (United States)

    Sinha, Deepak Kumar; Lakshmi, Mulagondla; Anuradha, Ghanta; Rahman, Shaik J; Siddiq, Ebrahimali A; Bentur, Jagadish S; Nair, Suresh

    2011-01-01

    The Asian rice gall midge, Orseolia oryzae (Wood-Mason), is a serious pest of rice. Investigations into the gall midge-rice interaction will unveil the underlying molecular mechanisms which, in turn, can be used as a tool to assist in developing suitable integrated pest management strategies. The insect gut is known to be involved in various physiological and biological processes including digestion, detoxification and interaction with the host. We have cloned and identified two genes, OoprotI and OoprotII, homologous to serine proteases with the conserved His(87), Asp(136) and Ser(241) residues. OoProtI shared 52.26% identity with mosquito-type trypsin from Hessian fly whereas OoProtII showed 52.49% identity to complement component activated C1s from the Hessian fly. Quantitative real time PCR analysis revealed that both the genes were significantly upregulated in larvae feeding on resistant cultivar than in those feeding on susceptible cultivar. These results provide an opportunity to understand the gut physiology of the insect under compatible or incompatible interactions with the host. Phylogenetic analysis grouped these genes in the clade containing proteases of phytophagous insects away from hematophagous insects.

  10. Characteristics of Water Budget Components in Paddy Rice Field under the Asian Monsoon Climate: Application of HSPF-Paddy Model

    Directory of Open Access Journals (Sweden)

    Young-Jin Kim

    2014-07-01

    Full Text Available The HSPF-Paddy model was applied to the Bochung watershed in Korea to compare water budget components by the land use types under the Asian monsoon climate. The calibration of HSPF-Paddy during 1992–2001 with PEST, a package program to optimize HSPF, and validation during 1985–1991 were carried out. The model efficiencies for monthly stream flow are 0.85 for calibration and 0.84 for validation. The simulation of annual mean runoff met the criteria of water budget analysis with the acceptable error level (less than 10 percent mean error. The simulation of the movement of water from paddy rice field to watershed was successful, and application of HSPF-Paddy coupled with PEST was able to improve accuracy of model simulation with reduced time and efforts for model calibration. The results of water budget analysis show that most of the outflow (86% for the urban area occurred through surface runoff, showing the highest rate among the land use types compared. Significant amounts of water are irrigated to paddy rice fields, and the runoff depth as well as evapotranspiration from paddy rice field is higher than other land use types. Hydrological characteristic of paddy rice field is that most of water movement occurred at the surface area, resulting from the low infiltration rate and manning’s coefficient, as well as ponded water throughout the growing season. Major impact on input and output of water were precipitation and runoff, respectively, influenced by an Asian monsoon climate.

  11. Habitat relationships of Asian elephants in shifting-cultivation landscapes of Meghalaya, Northeast India

    Science.gov (United States)

    Bruce G. Marcot; Ashish Kumar; G. Talukdar; A.K. Srivastava

    2011-01-01

    In Asia and India, Asian elephants (Elaphas maximus) attain their highest densities and numbers in Meghalaya, particularly in Garo Hills, of northeast India. Little quantitative work has been done on elephant-habitat relationships in this region where the species' distribution is known to be highly fragmented. If elephants and their habitat...

  12. An Investigation of Factors Affecting the Management of Risk for the Rice Cultivating Women in Sari Town with LISREL Application

    Directory of Open Access Journals (Sweden)

    M. charmchian Langerodi

    2016-03-01

    Full Text Available Introduction Agriculture relies on nature and farmers face environmental, social, financial and legal issues that makes farming to be consistently and strongly associated with risk. Agriculture can be considered to be the most risky economic venture. Ahmadi (1 listed several main sources of risk that farmers face. Economic risk includes price fluctuations for raw materials such as seed and fertilizer and for machinery at the pre-market delivery stage, difficulty obtaining bank credit and loans, price volatility for products in the post market delivery stage, inconsistent government policies for products and global fluctuations in the price of products. Social risk includes theft of crops, production and agricultural machinery and war. Nature-related risk includes natural disasters, climate change, agricultural pests and diseases. Market risk includes changes in the price of raw materials and products and increasing interest rates. Given that the range of agricultural activities having critical risk are diverse and the climate can vary widely, more sophisticated services are needed to meet the demands, cope with hazards and decrease risk. Understanding how women rice farmers deal with risk is essential for educators, and agriculture-related industries such as insurance, and policymakers. If the attitudes of these women towards risk are accurately recognized, risk management strategies, risk-related educational programs and risk strategies can be designed to meet their needs. The overallaim of this research isto investigate factors affecting risk management, and proposing and designing a model among rice cultivating women in Sari. Materials and Methods: The population of the study comprised 1677rice cultivating women in Sari of whom 248 were selected through stratified random sampling. A combination of quantitative, and descriptive-inferential statistics served as the methodology for the study and SPSS 16 and LISREL were applied for data analysis

  13. Utilization of composted sugar industry waste (pressmud) to improve properties of sodic soil for rice cultivation.

    Science.gov (United States)

    Seth, Rashi; Chandra, R; Kumar, Narendra; Tyagi, A K

    2005-07-01

    Sulphitation pressmud (SPM) and its composts were prepared by heap, pit, NADEP and vermicomposting methods and their effects were compared with soil properties and growth, yield and nutrient uptake by rice in a sodic soil under pot conditions. Application of 15 t ha(-1) SPM and its different composts significantly increased the plant height and dry matter accumulation at different intervals, grain and straw yields and N, P and K uptake by the crop over the control. NADEP compost of SPM alone recorded the maximum and significant plant height by 8.5 to 19.3% and plant dry matter by 14.6 to 32.8% over the raw SPM at different intervals. NADEP composts of SPM alone and SPM + rice straw were also found to be superior than raw SPM by recording 34.8 and 27.8% more grain yield respectively. The SPM composts prepared by NADEP and SPM by vermicomposting methods significantly accumulated higher N and K in rice grains and straw, while NADEP compost of SPM and SPM + rice straw recorded more P in grains and straw than raw SPM. Application of SPM and its composts reduced the pH, EC and bulk density of the soil after rice harvesting, though the reductions were not significant in comparison to the control. However, these treatments increased the soil organic C by 33.33 to 69.0%, available N by 41.4 to 74.8%, available P by 47.1 to 97.8%, available K by 11.8 to 59.2% and available S by 10.3 to 90.7% over the control. NADEP composts, in general, were found to be superior than the raw SPM and other composts in residual soil nutrient content after rice crop.

  14. Determination of Cadmium and Lead levels in high consumed rice (Oryza Sativa L. cultivated in Lorestan province and its comparison with national standards

    Directory of Open Access Journals (Sweden)

    roshanak Hedayatifar

    2011-03-01

    Full Text Available Rice is the main food of people in Iran and about 2.4 billion of the world population. Although its cultivation areas are less than wheat but 85% of the total product is used by people. Consumption of rice per person is estimated 42.5 kg in Iran. So it is the second high consumed agricultural product. The aim of this study was determination amount of toxic and heavy metals in high consumed rice varites cultivated in different areas of Lorestan province. Materials and Methods: In this study 99 rice samples (Tarem and Domsiah cultivated in three areas of Lorestan( khorramabad, Dorud and Borujerd province were collected. Amount of Lead and Cadmium were analyzed by atomic absorption model BRAIC WFX 130. Data were gathered and analyzed by SPSS software and compared with national standards. Results: The results for Cd and Pb were 0.037±0.06 and 0.077±0.08 mg/kg respectively. Conclusion: Cadmium and Lead levels in rice samples caltivated in Lorestan province were less than Permissible limit, so there is no risk for human health.

  15. From flooded to aerobic conditions in rice cultivation: consequences for zinc uptake

    NARCIS (Netherlands)

    Gao, X.; Zou, C.; Fan, X.; Zhang, F.S.; Hoffland, E.

    2006-01-01

    Scarcity of water causes a shift from flooded to aerobic conditions for rice production in zinc deficient areas in Northern China. This shift alters soil conditions that affect zinc availability to the crop. This paper concerns the effect of aerobic compared to flooded conditions on crop biomass

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

    Science.gov (United States)

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

    2015-02-20

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

  17. Eliminating Aluminum Toxicity in an Acid Sulfate Soil for Rice Cultivation Using Plant Growth Promoting Bacteria

    Directory of Open Access Journals (Sweden)

    Qurban Ali Panhwar

    2015-02-01

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

  18. High levels of inorganic arsenic in rice in areas where arsenic-contaminated water is used for irrigation and cooking.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-10-15

    Rice is the staple food for the people of arsenic endemic South (S) and South-East (SE) Asian countries. In this region, arsenic contaminated groundwater has been used not only for drinking and cooking purposes but also for rice cultivation during dry season. Irrigation of arsenic-contaminated groundwater for rice cultivation has resulted high deposition of arsenic in topsoil and uptake in rice grain posing a serious threat to the sustainable agriculture in this region. In addition, cooking rice with arsenic-contaminated water also increases arsenic burden in cooked rice. Inorganic arsenic is the main species of S and SE Asian rice (80 to 91% of the total arsenic), and the concentration of this toxic species is increased in cooked rice from inorganic arsenic-rich cooking water. The people of Bangladesh and West Bengal (India), the arsenic hot spots in the world, eat an average of 450g rice a day. Therefore, in addition to drinking water, dietary intake of arsenic from rice is supposed to be another potential source of exposure, and to be a new disaster for the population of S and SE Asian countries. Arsenic speciation in raw and cooked rice, its bioavailability and the possible health hazard of inorganic arsenic in rice for the population of S and SE Asia have been discussed in this review. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Comparison of the Composition and Antioxidant Activities of Phenolics from the Fruiting Bodies of Cultivated Asian Culinary-Medicinal Mushrooms.

    Science.gov (United States)

    Lin, Shaoling; Ching, Lai Tsz; Ke, Xinxin; Cheung, Peter Chi Keung

    2016-01-01

    The composition profile and the antioxidant properties of phenolics in water extracts obtained from the fresh fruiting bodies of 4 common cultivated Asian edible mushrooms-Agrocybe aegerita, Pleurotus ostreatus, P. eryngii, and Pholiota nameko were compared. The water extract from A. aegerita (AaE) had the highest total phenolic content (TPC) at 54.18 ± 0.27 gallic acid equivalents (μmol/L)/mg extract (P mushrooms were evaluated against 2,2-diphenyl-l-(2,4,6-trinitrophenyl) hydrazyl diphenylpicrylhydrazyl (DPPH), superoxide anion radicals, hydroxyl radicals, and hydrogen peroxide. Based on halfmaximal effective concentrations, AaE was more effective in scavenging hydrogen peroxide (mushroom water extracts. The differences in the half-maximal effective concentrations of individual mushroom water extracts were probably the result of the different numbers and amounts of individual phenolic acids in the extracts. The antioxidant activities of the mushroom water extracts were correlated with their TPC. The strongest antioxidant properties of AaE were consistent with its highest TPC and with the largest number and amount of phenolics identified in the extract. These results indicated that cultivated edible mushrooms could be a potential source of natural antioxidants with free radical scavenging properties for application as a functional food ingredient.

  20. Pollen and phytolith evidence for rice cultivation and vegetation change during the mid-late Holocene at the Jiangli site, Suzhou, East China.

    Science.gov (United States)

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

    2014-01-01

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

  1. Pollen and phytolith evidence for rice cultivation and vegetation change during the mid-late holocene at the Jiangli site, Suzhou, East China.

    Science.gov (United States)

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

    2014-01-01

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

  2. Pollen and phytolith evidence for rice cultivation and vegetation change during the mid-late Holocene at the Jiangli site, Suzhou, East China.

    Directory of Open Access Journals (Sweden)

    Zhenwei Qiu

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

  3. Pollen and phytolith evidence for rice cultivation and vegetation change during the mid-late holocene at the Jiangli site, Suzhou, East China.

    Directory of Open Access Journals (Sweden)

    Zhenwei Qiu

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-04-13

    MicroRNAs (miRNAs) are small noncoding RNAs that direct posttranscriptional gene silencing in eukaryotes. They are frequently clustered in the genomes of animals and can be independently transcribed or simultaneously transcribed into single polycistronic transcripts. Only a few miRNA clusters have been described in plants, and most of them are generated from independent transcriptional units. Here, we used a combination of bioinformatic tools and experimental analyses to discover new polycistronic miRNAs in rice. A genome-wide analysis of clustering patterns of MIRNA loci in the rice genome was carried out using a criterion of 3 kb as the maximal distance between two miRNAs. This analysis revealed 28 loci with the ability to form the typical hairpin structure of miRNA precursors in which 2 or more mature miRNAs mapped along the same structure. RT-PCR provided evidence for the polycistronic nature of seven miRNA precursors containing homologous or nonhomologous miRNA species. Polycistronic miRNAs and candidate polycistronic miRNAs are located across different rice chromosomes, except chromosome 12, and resided in both duplicated and nonduplicated chromosomal regions. Finally, most polycistronic and candidate polycistronic miRNAs showed a pattern of conservation in the genome of rice species with an AA genome. The diversity in the organization of MIR genes that are transcribed as polycistrons suggests a versatile mechanism for the control of gene expression in different biological processes and supports additional levels of complexity in miRNA functioning in plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Convergent Loss of Awn in Two Cultivated Rice Species Oryza sativa and Oryza glaberrima Is Caused by Mutations in Different Loci.

    Science.gov (United States)

    Furuta, Tomoyuki; Komeda, Norio; Asano, Kenji; Uehara, Kanako; Gamuyao, Rico; Angeles-Shim, Rosalyn B; Nagai, Keisuke; Doi, Kazuyuki; Wang, Diane R; Yasui, Hideshi; Yoshimura, Atsushi; Wu, Jianzhong; McCouch, Susan R; Ashikari, Motoyuki

    2015-09-02

    A long awn is one of the distinct morphological features of wild rice species. This organ is thought to aid in seed dispersal and prevent predation by animals. Most cultivated varieties of Oryza sativa and Oryza glaberrima, however, have lost the ability to form long awns. The causal genetic factors responsible for the loss of awn in these two rice species remain largely unknown. Here, we evaluated three sets of chromosome segment substitution lines (CSSLs) in a common O. sativa genetic background (cv. Koshihikari) that harbor genomic fragments from Oryza nivara, Oryza rufipogon, and Oryza glaberrima donors. Phenotypic analyses of these libraries revealed the existence of three genes, Regulator of Awn Elongation 1 (RAE1), RAE2, and RAE3, involved in the loss of long awns in cultivated rice. Donor segments at two of these genes, RAE1 and RAE2, induced long awn formation in the CSSLs whereas an O. sativa segment at RAE3 induced long awn formation in O. glaberrima. These results suggest that the two cultivated rice species, O. sativa and O. glaberrima, have taken independent paths to become awnless. Copyright © 2015 Furuta et al.

  7. Convergent Loss of Awn in Two Cultivated Rice Species Oryza sativa and Oryza glaberrima Is Caused by Mutations in Different Loci

    Science.gov (United States)

    Furuta, Tomoyuki; Komeda, Norio; Asano, Kenji; Uehara, Kanako; Gamuyao, Rico; Angeles-Shim, Rosalyn B.; Nagai, Keisuke; Doi, Kazuyuki; Wang, Diane R.; Yasui, Hideshi; Yoshimura, Atsushi; Wu, Jianzhong; McCouch, Susan R.; Ashikari, Motoyuki

    2015-01-01

    A long awn is one of the distinct morphological features of wild rice species. This organ is thought to aid in seed dispersal and prevent predation by animals. Most cultivated varieties of Oryza sativa and Oryza glaberrima, however, have lost the ability to form long awns. The causal genetic factors responsible for the loss of awn in these two rice species remain largely unknown. Here, we evaluated three sets of chromosome segment substitution lines (CSSLs) in a common O. sativa genetic background (cv. Koshihikari) that harbor genomic fragments from Oryza nivara, Oryza rufipogon, and Oryza glaberrima donors. Phenotypic analyses of these libraries revealed the existence of three genes, Regulator of Awn Elongation 1 (RAE1), RAE2, and RAE3, involved in the loss of long awns in cultivated rice. Donor segments at two of these genes, RAE1 and RAE2, induced long awn formation in the CSSLs whereas an O. sativa segment at RAE3 induced long awn formation in O. glaberrima. These results suggest that the two cultivated rice species, O. sativa and O. glaberrima, have taken independent paths to become awnless. PMID:26338659

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2015-01-01

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

  10. Traps as treats: a traditional sticky rice snack persisting in rapidly changing Asian kitchens.

    Science.gov (United States)

    Schwallier, Rachel; de Boer, Hugo J; Visser, Natasja; van Vugt, Rogier R; Gravendeel, Barbara

    2015-03-24

    An accessory to modern developing economies includes a shift from traditional, laborious lifestyles and cuisine to more sedentary careers, recreation and convenience-based foodstuffs. Similar changes in the developed western world have led to harmful health consequences. Minimization of this effect in current transitional cultures could be met by placing value on the maintenance of heritage-rich food. Vitally important to this is the preservation and dissemination of knowledge of these traditional foods. Here, we investigate the history and functionality of a traditional rice snack cooked in Nepenthes pitchers, one of the most iconic and recognizable plants in the rapidly growing economic environment of Southeast Asia. Social media was combined with traditional ethnobotanical surveys to conduct investigations throughout Malaysian Borneo. Interviews were conducted with 25 market customers, vendors and participants from various ethnical groups with an in-depth knowledge of glutinous rice cooked in pitcher plants. The acidity of pitcher fluid was measured during experimental cooking to analyze possible chemical avenues that might contribute to rice stickiness. Participants identifying the snack were almost all (96%) from indigenous Bidayuh or Kadazandusun tribal decent. They prepare glutinous rice inside pitcher traps for tradition, vessel functionality and because they thought it added fragrance and taste to the rice. The pH and chemical activity of traps analyzed suggest there is no corresponding effect on rice consistency. Harvest of pitchers does not appear to decrease the number of plants in local populations. The tradition of cooking glutinous rice snacks in pitcher plants, or peruik kera in Malay, likely carries from a time when cooking vessels were more limited, and persists only faintly in tribal culture today because of value placed on maintaining cultural heritage. Social media proved a valuable tool in our research for locating research areas and in

  11. Genetic Loci Governing Grain Yield and Root Development under Variable Rice Cultivation Conditions.

    Science.gov (United States)

    Catolos, Margaret; Sandhu, Nitika; Dixit, Shalabh; Shamsudin, Noraziya A A; Naredo, Ma E B; McNally, Kenneth L; Henry, Amelia; Diaz, Ma G; Kumar, Arvind

    2017-01-01

    Drought is the major abiotic stress to rice grain yield under unpredictable changing climatic scenarios. The widely grown, high yielding but drought susceptible rice varieties need to be improved by unraveling the genomic regions controlling traits enhancing drought tolerance. The present study was conducted with the aim to identify quantitative trait loci (QTLs) for grain yield and root development traits under irrigated non-stress and reproductive-stage drought stress in both lowland and upland situations. A mapping population consisting of 480 lines derived from a cross between Dular (drought-tolerant) and IR64-21 (drought susceptible) was used. QTL analysis revealed three major consistent-effect QTLs for grain yield (qDTY1.1, qDTY1.3 , and qDTY8.1 ) under non-stress and reproductive-stage drought stress conditions, and 2 QTLs for root traits (qRT9.1 for root-growth angle and qRT5.1 for multiple root traits, i.e., seedling-stage root length, root dry weight and crown root number). The genetic locus qDTY1.1 was identified as hotspot for grain yield and yield-related agronomic and root traits. The study identified significant positive correlations among numbers of crown roots and mesocotyl length at the seedling stage and root length and root dry weight at depth at later stages with grain yield and yield-related traits. Under reproductive stage drought stress, the grain yield advantage of the lines with QTLs ranged from 24.1 to 108.9% under upland and 3.0-22.7% under lowland conditions over the lines without QTLs. The lines with QTL combinations qDTY1.3 +qDTY8.1 showed the highest mean grain yield advantage followed by lines having qDTY1.1 +qDTY8.1 and qDTY1.1 +qDTY8.1 +qDTY1.3 , across upland/lowland reproductive-stage drought stress. The identified QTLs for root traits, mesocotyl length, grain yield and yield-related traits can be immediately deployed in marker-assisted breeding to develop drought tolerant high yielding rice varieties.

  12. Exploring the areas of applicability of whole-genome prediction methods for Asian rice (Oryza sativa L.).

    Science.gov (United States)

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

    2015-01-01

    Our simulation results clarify the areas of applicability of nine prediction methods and suggest the factors that affect their accuracy at predicting empirical traits. Whole-genome prediction is used to predict genetic value from genome-wide markers. The choice of method is important for successful prediction. We compared nine methods using empirical data for eight phenological and morphological traits of Asian rice cultivars (Oryza sativa L.) and data simulated from real marker genotype data. The methods were genomic BLUP (GBLUP), reproducing kernel Hilbert spaces regression (RKHS), Lasso, elastic net, random forest (RForest), Bayesian lasso (Blasso), extended Bayesian lasso (EBlasso), weighted Bayesian shrinkage regression (wBSR), and the average of all methods (Ave). The objectives were to evaluate the predictive ability of these methods in a cultivar population, to characterize them by exploring the area of applicability of each method using simulation, and to investigate the causes of their different accuracies for empirical traits. GBLUP was the most accurate for one trait, RKHS and Ave for two, and RForest for three traits. In the simulation, Blasso, EBlasso, and Ave showed stable performance across the simulated scenarios, whereas the other methods, except wBSR, had specific areas of applicability; wBSR performed poorly in most scenarios. For each method, the accuracy ranking for the empirical traits was largely consistent with that in one of the simulated scenarios, suggesting that the simulation conditions reflected the factors that affected the method accuracy for the empirical results. This study will be useful for genomic prediction not only in Asian rice, but also in populations from other crops with relatively small training sets and strong linkage disequilibrium structures.

  13. The Asian Rice Gall Midge (Orseolia oryzae Mitogenome Has Evolved Novel Gene Boundaries and Tandem Repeats That Distinguish Its Biotypes.

    Directory of Open Access Journals (Sweden)

    Isha Atray

    Full Text Available The complete mitochondrial genome of the Asian rice gall midge, Orseolia oryzae (Diptera; Cecidomyiidae was sequenced, annotated and analysed in the present study. The circular genome is 15,286 bp with 13 protein-coding genes, 22 tRNAs and 2 ribosomal RNA genes, and a 578 bp non-coding control region. All protein coding genes used conventional start codons and terminated with a complete stop codon. The genome presented many unusual features: (1 rearrangement in the order of tRNAs as well as protein coding genes; (2 truncation and unusual secondary structures of tRNAs; (3 presence of two different repeat elements in separate non-coding regions; (4 presence of one pseudo-tRNA gene; (5 inversion of the rRNA genes; (6 higher percentage of non-coding regions when compared with other insect mitogenomes. Rearrangements of the tRNAs and protein coding genes are explained on the basis of tandem duplication and random loss model and why intramitochondrial recombination is a better model for explaining rearrangements in the O. oryzae mitochondrial genome is discussed. Furthermore, we evaluated the number of iterations of the tandem repeat elements found in the mitogenome. This led to the identification of genetic markers capable of differentiating rice gall midge biotypes and the two Orseolia species investigated.

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

    Science.gov (United States)

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

    2008-01-01

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

  15. Temporary wetland restoration after rice cultivation: is soil transfer required for aquatic plant colonization?

    Directory of Open Access Journals (Sweden)

    Muller I.

    2013-09-01

    Full Text Available Mediterranean temporary wetlands have considerably declined in recent decades. Today, opportunities arise for the restoration of these wetlands due to land-use changes, such as the abandonment of cultivation. One critical question is whether communities, such as those observed in natural temporary wetlands, can develop alone or if active restoration should be implemented. In a series of experimental mesocosms, we transferred soil from several temporary wetlands chosen as a set of reference ecosystems. Four months after soil transfer, vegetation in transfer mesocosms was compared to that derived from spontaneous colonization (control mesocoms. Transfer mesocosms are colonized by all target hydrophyte species transferred with the soil and the resulting communities are similar to those of reference ecosystems. They also have fewer non-target species than the control mesocosms. Even though the study period was not sufficient to draw any definitive conclusion regarding the utility of forced dispersion by soil transfer, the preliminary results are promising for an application on a larger scale.

  16. Complete Genomic Structure of the Cultivated Rice Endophyte Azospirillum sp. B510

    Science.gov (United States)

    Kaneko, Takakazu; Minamisawa, Kiwamu; Isawa, Tsuyoshi; Nakatsukasa, Hiroki; Mitsui, Hisayuki; Kawaharada, Yasuyuki; Nakamura, Yasukazu; Watanabe, Akiko; Kawashima, Kumiko; Ono, Akiko; Shimizu, Yoshimi; Takahashi, Chika; Minami, Chiharu; Fujishiro, Tsunakazu; Kohara, Mitsuyo; Katoh, Midori; Nakazaki, Naomi; Nakayama, Shinobu; Yamada, Manabu; Tabata, Satoshi; Sato, Shusei

    2010-01-01

    We determined the nucleotide sequence of the entire genome of a diazotrophic endophyte, Azospirillum sp. B510. Strain B510 is an endophytic bacterium isolated from stems of rice plants (Oryza sativa cv. Nipponbare). The genome of B510 consisted of a single chromosome (3 311 395 bp) and six plasmids, designated as pAB510a (1 455 109 bp), pAB510b (723 779 bp), pAB510c (681 723 bp), pAB510d (628 837 bp), pAB510e (537 299 bp), and pAB510f (261 596 bp). The chromosome bears 2893 potential protein-encoding genes, two sets of rRNA gene clusters (rrns), and 45 tRNA genes representing 37 tRNA species. The genomes of the six plasmids contained a total of 3416 protein-encoding genes, seven sets of rrns, and 34 tRNAs representing 19 tRNA species. Eight genes for plasmid-specific tRNA species are located on either pAB510a or pAB510d. Two out of eight genomic islands are inserted in the plasmids, pAB510b and pAB510e, and one of the islands is inserted into trnfM-CAU in the rrn located on pAB510e. Genes other than the nif gene cluster that are involved in N2 fixation and are homologues of Bradyrhizobium japonicum USDA110 include fixABCX, fixNOQP, fixHIS, fixG, and fixLJK. Three putative plant hormone-related genes encoding tryptophan 2-monooxytenase (iaaM) and indole-3-acetaldehyde hydrolase (iaaH), which are involved in IAA biosynthesis, and ACC deaminase (acdS), which reduces ethylene levels, were identified. Multiple gene-clusters for tripartite ATP-independent periplasmic-transport systems and a diverse set of malic enzymes were identified, suggesting that B510 utilizes C4-dicarboxylate during its symbiotic relationship with the host plant. PMID:20047946

  17. 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.

  18. Combinations of the Ghd7, Ghd8 and Hd1 genes largely define the ecogeographical adaptation and yield potential of cultivated rice.

    Science.gov (United States)

    Zhang, Jia; Zhou, Xiangchun; Yan, Wenhao; Zhang, Zhanyi; Lu, Li; Han, Zhongmin; Zhao, Hu; Liu, Haiyang; Song, Pan; Hu, Yong; Shen, Guojing; He, Qin; Guo, Sibin; Gao, Guoqing; Wang, Gongwei; Xing, Yongzhong

    2015-12-01

    Rice cultivars have been adapted to favorable ecological regions and cropping seasons. Although several heading date genes have separately made contributions to this adaptation, the roles of gene combinations are still unclear. We employed a map-based cloning approach to isolate a heading date gene, which coordinated the interaction between Ghd7 and Ghd8 to greatly delay rice heading. We resequenced these three genes in a germplasm collection to analyze natural variation. Map-based cloning demonstrated that the gene largely affecting the interaction between Ghd7 and Ghd8 was Hd1. Natural variation analysis showed that a combination of loss-of-function alleles of Ghd7, Ghd8 and Hd1 contributes to the expansion of rice cultivars to higher latitudes; by contrast, a combination of pre-existing strong alleles of Ghd7, Ghd8 and functional Hd1 (referred as SSF) is exclusively found where ancestral Asian cultivars originated. Other combinations have comparatively larger favorable ecological scopes and acceptable grain yield. Our results indicate that the combinations of Ghd7, Ghd8 and Hd1 largely define the ecogeographical adaptation and yield potential in rice cultivars. Breeding varieties with the SSF combination are recommended for tropical regions to fully utilize available energy and light resources and thus produce greater yields. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  19. Differential analysis of protein expression in RNA-binding-protein transgenic and parental rice seeds cultivated under salt stress.

    Science.gov (United States)

    Nakamura, Rika; Nakamura, Ryosuke; Adachi, Reiko; Hachisuka, Akiko; Yamada, Akiyo; Ozeki, Yoshihiro; Teshima, Reiko

    2014-02-07

    Transgenic plants tolerant to various environmental stresses are being developed to ensure a consistent food supply. We used a transgenic rice cultivar with high saline tolerance by introducing an RNA-binding protein (RBP) from the ice plant (Mesembryanthemum crystallinum); differences in salt-soluble protein expression between nontransgenic (NT) and RBP rice seeds were analyzed by 2D difference gel electrophoresis (2D-DIGE), a gel-based proteomic method. To identify RBP-related changes in protein expression under salt stress, NT and RBP rice were cultured with or without 200 mM sodium chloride. Only two protein spots differed between NT and RBP rice seeds cultured under normal conditions, one of which was identified as a putative abscisic acid-induced protein. In NT rice seeds, 91 spots significantly differed between normal and salt-stress conditions. Two allergenic proteins of NT rice seeds, RAG1 and RAG2, were induced by high salt. In contrast, RBP rice seeds yielded seven spots and no allergen spots with significant differences in protein expression between normal and salt-stress conditions. Therefore, expression of fewer proteins was altered in RBP rice seeds by high salt than those in NT rice seeds.

  20. Differential Analysis of Protein Expression in RNA-Binding-Protein Transgenic and Parental Rice Seeds Cultivated under Salt Stress

    Science.gov (United States)

    2015-01-01

    Transgenic plants tolerant to various environmental stresses are being developed to ensure a consistent food supply. We used a transgenic rice cultivar with high saline tolerance by introducing an RNA-binding protein (RBP) from the ice plant (Mesembryanthemum crystallinum); differences in salt-soluble protein expression between nontransgenic (NT) and RBP rice seeds were analyzed by 2D difference gel electrophoresis (2D-DIGE), a gel-based proteomic method. To identify RBP-related changes in protein expression under salt stress, NT and RBP rice were cultured with or without 200 mM sodium chloride. Only two protein spots differed between NT and RBP rice seeds cultured under normal conditions, one of which was identified as a putative abscisic acid-induced protein. In NT rice seeds, 91 spots significantly differed between normal and salt-stress conditions. Two allergenic proteins of NT rice seeds, RAG1 and RAG2, were induced by high salt. In contrast, RBP rice seeds yielded seven spots and no allergen spots with significant differences in protein expression between normal and salt-stress conditions. Therefore, expression of fewer proteins was altered in RBP rice seeds by high salt than those in NT rice seeds. PMID:24410502

  1. Rice Cultivation Methods and Their Sustainability Aspects: Organic and Conventional Rice Production in Industrialized Tropical Monsoon Asia with a Dual Cropping System

    Directory of Open Access Journals (Sweden)

    Hung-Chun Lin

    2016-06-01

    Full Text Available Options to tackle the sustainability challenges faced in the production of rice, including global and local environmental perspectives, need to be discussed. Here, the global warming potential, water consumption and cumulative energy demand were analyzed using a life-cycle assessment to highlight the sustainability aspects of rice production in Taiwan, where a mixed organic and conventional rice production with a dual cropping system is practiced. The results show that the conventional farming method practiced in Houbi district contributes less to global warming and annual water consumption and consumes less energy than the organic method practiced in Luoshan village on a grain weight basis. It is also more lucrative for farmers because of the higher rice yield. Considering the yield ratio based on the data from two districts, the regional characteristics are more responsible for these differences. Giving up dual cropping to avail water to other sectors by fallowing during the second cropping season is preferable from the GHG emission and productivity perspectives. However, because water shortages usually occur in the first cropping season, it is more realistic to fallow during the first cropping season when domestic and other industrial users have the higher priority. The results presented here can serve as the foundation for exploring the possibilities of options, such as new biorefinery technologies and water allocation policies, in relation to influences on GHG emissions and the national self-sufficiency of rice.

  2. Screening of filamentous fungi to produce xylanase and xylooligosaccharides in submerged and solid-state cultivations on rice husk, soybean hull, and spent malt as substrates.

    Science.gov (United States)

    da Silva Menezes, Bruna; Rossi, Daniele Misturini; Ayub, Marco Antônio Záchia

    2017-03-01

    We investigated the enzymatic complex produced by selected fungi strains isolated from the environment using the agro-industrial residues rice husk, soybean hull, and spent malt as substrates. Microbial growth was carried out in solid-state cultivation (SSC) and in submerged cultivations (SC) and the enzymatic activities of xylanase, cellulase, β-xylosidase, and β-glucosidase were determined. All substrates were effective in inducing enzymatic activities, with one strain of Aspergillus brasiliensis BLf1 showing maximum activities for all enzymes, except for cellulases. Using this fungus, the enzymatic activities of xylanase, cellulase, and β-glucosidase were generally higher in SSC compared to SC, producing maxima activities of 120.5, 25.3 and 47.4 U g-1 of dry substrate, respectively. β-xylosidase activity of 28.1 U g-1 of dry substrate was highest in SC. Experimental design was carried out to optimize xylanase activity by A. brasiliensis BLf1 in SSC using rice husk as substrate, producing maximum xylanase activity 183.5 U g-1 dry substrate, and xylooligosaccharides were produced and characterized. These results suggest A. brasiliensis BLf1 can be used to produce important lytic enzymes to be applied in the preparation of xylooligosaccharides.

  3. Differential Analysis of Protein Expression in RNA-Binding-Protein Transgenic and Parental Rice Seeds Cultivated under Salt Stress

    OpenAIRE

    Nakamura, Rika; Nakamura, Ryosuke; Adachi, Reiko; Hachisuka, Akiko; Yamada, Akiyo; Ozeki, Yoshihiro; Teshima, Reiko

    2014-01-01

    Transgenic plants tolerant to various environmental stresses are being developed to ensure a consistent food supply. We used a transgenic rice cultivar with high saline tolerance by introducing an RNA-binding protein (RBP) from the ice plant (Mesembryanthemum crystallinum); differences in salt-soluble protein expression between nontransgenic (NT) and RBP rice seeds were analyzed by 2D difference gel electrophoresis (2D-DIGE), a gel-based proteomic method. To identify RBP-related changes in pr...

  4. Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios Desenvolvimento foliar de arroz cultivado e arroz vermelho em cenários de aumento de temperatura

    Directory of Open Access Journals (Sweden)

    Nereu A. Streck

    2013-02-01

    Full Text Available 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 date using 100 years of synthetic daily weather data and six climate scenarios, including current, +1, +2, +3, +4 and +5 ºC increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum temperature. The increase in air temperature scenarios decreased the duration of the EM-FL phase in the earlier emergence dates (08/20, 09/20, 10/20 whereas in mid (11/20 and late emergence dates (12/20 and 01/20 the longest EM-FL phase was in the symmetric +5 ºC scenario and the shortest duration was in the asymmetric +3 and +4 ºC scenarios. The timing of the onset of flooding irrigation and nitrogen dressing may be altered if global warming takes place and weedy red rice has a potential to enhance its competitiveness with cultivated rice in future climates.Objetivou-se com este estudo simular o desenvolvimento foliar de genótipos de arroz cultivados e biótipos invasores de arroz vermelho em cenários de mudança climática em Santa Maria, Rio Grande do Sul, Brasil. Um modelo de aparecimento de folhas foi usado para simular o número de folhas acumuladas, representadas pelo Estádio de Haun, a partir da emergência da cultura até o aparecimento da folha bandeira (EM-FB. Foram utilizados três genótipos de arroz cultivados e dois biótipos de arroz vermelho, em seis épocas de emergência. O modelo foi rodado em cem anos de seis cenários climáticos: atual, +1, +2, +3, +4 e +5 ºC, com aumentos simétricos e assimétricos na

  5. Prevalence, isolation and characterization of Bacillus cereus strains from rice of local cultivators of Sabah, Sarawak, and Peninsular Malaysia

    Science.gov (United States)

    Sawei, Jelin; Sani, Norrakiah Abdullah

    2016-11-01

    Bacillus cereus is a spore-forming, facultative anaerobic, motile microorganism that has been identified as a causative agent of two types of gastrointestinal diseases such as emetic and diarrhea. This foodborne pathogen is found in both vegetative cells and endospores form in foods such as rice either raw or cooked. The aim of this study is to investigate and determine the prevalence, characterize and identify the isolation of vegetative cells and endospores of B. cereus in thirty varieties (n=3) of raw rice from Sabah, Sarawak and Peninsular Malaysia. A total of 90 (n=90) raw rice were examined and 84 (93.33%) samples were positive to vegetative cells of B. cereus. However, only 32 (35.56%) samples were positive for endospore cells that able to germinate after samples were heated at 75°C for 15 mins. The mean log cfu/g for vegetative cells were higher range (0.00 - 4.1533) than visible endospores (0.00 - 3.7533 mean log cfu/g). Sample of raw red rice (UKMRC9) had significantly higher contamination by both vegetative cells and endospores at p<0.05, than the other raw rice samples.

  6. Towards higher nitrogen efficiency in European rice cultivation : a case study for the Camargue, South of France

    NARCIS (Netherlands)

    Stutterheim, N.C.

    1995-01-01

    This study focuses on an increase in the efficiency of fertilizer nitrogen in irrigated, direct seeded rice. Three indicators for efficiency were used: agronomic efficiency, utilization efficiency and recovery. Experiments were conducted in the Camargue in the South of France, to quantify

  7. Effect of fluoride on photosynthesis, growth and accumulation of four widely cultivated rice (Oryza sativa L.) varieties in India.

    Science.gov (United States)

    Mondal, Naba Kumar

    2017-10-01

    Long-term use of fluoride contaminated groundwater to irrigate crops; especially paddy rice (Oryza sativa L.) has resulted in elevated soil fluoride levels in Eastern India. There is, therefore, growing concern regarding accumulation of fluoride in rice grown on these soils. A laboratory experiment was conducted to investigate the effect of F on germination and phytotoxicity of four varieties of rice (Orzya sativa L.) (MTU-1010; IET-4094; IET-4786 and GB-1) grown in petri dish in a green house with inorganic sodium fluoride (NaF). Three different levels (0, 5, 10 and 20mg/L) of NaF solution were applied. At the end of the experiment (28 days), biochemical analysis (pigment, sugar, protein, amino acid and phenol), lipid peroxidation, root ion leakage and catalase activity along with fluoride accumulation and fresh and dry weight of roots and shoots of four cultivars were measured. The results revealed that all the four studied varieties exhibited gradual decrease of germination pattern with increasing concentration of F. Pigment and growth morphological study clearly demonstrated that the variety IET-4094 was the least influenced by F compare to the other three varieties of rice. The translocation factor (TF) was recorded to be the highest for variety IET-4786 (0.215 ± 0.03) at 5mg/L F concentration. All the four varieties showed higher level of fluoride accumulation in root than in shoot. Variable results were recorded for biochemical parameters and lipid peroxidation. Catalase activity and relative conductivity (root ion leakage) gradually increased with increasing F concentration for all the four varieties. It is speculated that fluoride accumulation in rice straw at very high levels will affect the feeding cattle and such contaminated straw could be a direct threat to their health and also, indirectly, to human health via presumably contaminated meat and milk. Copyright © 2017. Published by Elsevier Inc.

  8. The use of 32P Method to Evaluate the Growth of Lowland Rice Cultivated in a System of Rice Intensification (SRI

    Directory of Open Access Journals (Sweden)

    A. Citraresmini

    2013-08-01

    Full Text Available A pot experiment has been conducted to evaluate the growth of the Dyah Suci, a lowland rice variety, in an SRI (System of Rice Intensification planting system. The phosphorus-32 (32P isotope technique was used to evaluate the growth of plants in relation with their phosphorus uptake. The uptake was assumed to vary in the same direction as the growth of the plant. The 32P uptake is assumed to vary in the opposite direction to the plant’s total phosphorus uptake. Here the 32P uptake is expressed in count per minutes (cpm which is then transformed to disintegration per minute (dpm. The results show that, in terms of promoting the plant’s uptake of phosphorus, the SRI planting system is superior to the conventional planting system, and it is manifested in the higher dry weight of straw and grain. From this experiment it is concluded that the 32P method can be used satisfactorily as a tool for explaining the relation between P-uptake and plant growth

  9. Factors affecting the soil arsenic bioavailability, accumulation in rice and risk to human health: a review.

    Science.gov (United States)

    Azam, Shah Md Golam Gousul; Sarker, Tushar C; Naz, Sabrina

    2016-10-01

    Arsenic (As), a class one carcinogen, reflects a disastrous environmental threat due to its presence in each and every compartment of the environment. The high toxicity of As is notably present in its inorganic forms. Irrigation with As contaminated groundwater in rice fields increases As concentration in topsoil and its bioavailability for rice crops. However, most of the As in paddy field topsoils is present as As(III) form, which is predominant in rice grain. According to the OECD-FAO, rice is the second most extensively cultivated cereal throughout the world. This cereal is a staple food for a large number of populations in most of the developing countries in sub-Saharan Africa, Latin America, South and South-east Asia. Rice consumption is one of the major causes of chronic As diseases including cancer for Asian populations. Thus, this review provides an overview concerning the conditions involved in soil that leads to As entrance into rice crops, phytotoxicity and metabolism of As in rice plants. Moreover, the investigations of the As uptake in raw rice grain are compiled, and the As biotransfer into the human diet is focused. The As uptake by rice crop represents an important pathway of As exposure in countries with high rice and rice-based food consumption because of its high (more than the hygienic level) As levels found in edible plant part for livestock and humans.

  10. Manejo de água e de fertilizante potássico na cultura de arroz irrigado Water and potassium fertilization management for irrigated rice cultivation

    Directory of Open Access Journals (Sweden)

    Alberto Baêta dos Santos

    1999-04-01

    Full Text Available O manejo da água de irrigação e as doses e épocas de aplicação de fertilizantes tornam-se aspectos de extrema importância no êxito do aproveitamento das várzeas para o cultivo de arroz (Oryza sativa L. irrigado ou este seguido de outras espécies. Com o objetivo de comparar distintas formas de manejo de água e de fertilizante potássico no comportamento do arroz irrigado, foram conduzidos experimentos por três anos consecutivos, em um Inceptissolo. Foram estudados os efeitos de manejo de água (MA1 - inundação contínua e MA2 - inundação intermitente seguida de contínua e o modo de aplicação de fertilizante potássico (K1 - na semeadura; K2 - parcelada e K3 - meia dose parcelada. O manejo de água apresentou efeito mais expressivo sobre o comportamento do arroz que o do fertilizante potássico. A inundação contínua durante todo o ciclo da cultura proporcionou maiores rendimentos de grãos, expressando maiores valores dos parâmetros produtivos, e melhorou a qualidade industrial dos grãos. Com esta irrigação, o parcelamento da adubação potássica aumentou o aproveitamento do fertilizante. Os manejos do fertilizante potássico afetaram diferentemente o comportamento da cultura do arroz nas distintas formas de manejo de água.Irrigation water levels and timing of potassium fertilization is extremely important for the use of lowlands for irrigated rice (Oryza sativa L. cultivation in crop rotation. A field experiment was conduced for three consecutive years in Inceptisol to study the effects of water management (WM1 - continuous flooding and WM2 - intermittent flooding followed continuous flooding and mode of potassium fertilizer application (K1 - at sowing; K2 - fractional application and K3 - fractional application of half levels on grain yield and yield components of irrigated rice. Water management presented expressive effect on rice performance as compared to potassium fertilization. Continuous flooding during whole

  11. GENE FLOW BETWEEN RED RICE AND CULTIVATED RICE ESTIMATED BY MICROSATELLITE MARKERS FLUXO GÊNICO ENTRE ARROZ VERMELHO E ARROZ CULTIVADO ESTIMADO POR MEIO DE MARCADORES MICROSSATÉLITES

    Directory of Open Access Journals (Sweden)

    Francisco , Moura Neto

    2007-09-01

    Full Text Available

    The study aimed to evaluate the capacity of SSR markers to detect the gene flow between the red rice (RR and the cultivated rice (CR. SSR is currently used in plant genomic analysis due to the high information content, to be co-dominant, and based on the PCR reaction. The field experiment was organized in ten concentric circles, 5 m to 50 m apart from a central red rice plant, assumed as the pollen donor. One hundred twenty rice CR plants, cv. BR-Irga 409, were planted in the intersections of the concentric circles and the twelve radii. From 51 SSR markers, four were selected due to their capacity to detect the polymorphism between RR and CR, aiming to identify RR alleles in seeds produced by BR-Irga 409 plants. The maximum distance found for gene flow between RR and CR plants was 10 m from the RR plant. In theory, at 0.1% cross pollination rate, this distance can generate 4,710 hybrids between RR and CR. In the next generation, about 3,532 plants would produce exclusively rice grains with red color. The SSR markers were able to identify the gene flow between RR and CR; therefore, they can be useful to increase the precision of cross pollination rate estimates in rice, mainly if used with other methodologies (e.g., herbicide tolerant plants.

    KEY WORDS: Cross pollination; microsatellite markers; Oryza sativa.

    Este trabalho objetivou avaliar a capacidade de marcadores SSR em detectar a ocorrência de fluxo gênico entre o arroz vermelho (AV e o arroz cultivado (AC. Marcadores SSR são utilizados em análise genômica de plantas devido ao alto conteúdo informativo, serem co-dominantes e baseados na reação de PCR. O ensaio de campo foi realizado em dez círculos concêntricos de 5 m a 50 m de distância, a partir de uma planta AV central, que foi a fonte

  12. EFFECT OF FLUCTUATION OF WETTING AND DRYING PHENOMENA ON SOIL FERTILITY STATUS UNDER RICE CULTIVATION IN WETLAND SOIL IN RWANDA

    Directory of Open Access Journals (Sweden)

    Hamudu Rukangantambara

    2014-01-01

    Full Text Available Since 1980, wetland s in Rwanda have been considered as important areas for agriculture intensification through improving food security and incomes to the farmers. However, changes in the soil nutrient status due to repeatedly wetting and drying phenomena may considerably affect soil fertility status thus leading to low crop productivity of the wetlands. This has consequently created fear to the wetland users especially the local farmers, extension workers and agronomists. The comparative study was conducted to assess the effect of drained and irrigated phenomena at Mamba, Rwasave and Rugeramigozi marshlands on soil fertility change under rice growing. 24 samples were taken with 12 samples under drained and 12 under irrigated areas. The samples were collected randomly from top soil ( 0- 20 cm. The following parameters were quantified; soil pH( H 2O in soil water suspension with ratio 1:2.5; Al exchangeable( 1N Kcl, organic carbon( walkely and black method in Sumner method modified (1984, Total nitrogen kjeldahl (TNK in Bremner modified method, available phosphorus ( bray 1. Bases exchangeable with 1 N ammonium acetate following AAS and CEC and available Fe, Zn, Cu and Mn (DTDA diethylenetriaminepentaacetic acid. Data analyses were processed with GEN STAT version 3. The results showed that the fluctuation of wet and dry water have significantly affected soil fertility status at p= 0,05. The phosphorus and potassium are in the low levels of deficiency 2.32 ppm and 47.72 ppm in irrigated area while crop requirement nutrients are 20 ppm and 200 ppm respectively. And Al is in toxic level conditions, 27.5% in drained area while rice tolerance is 20%. Fe was 641.51 ppm in irrigated area while requirement narrowed to 300 ppm. As conclusion, the soil fertility is low and toxic which constitutes a limitation. The wetland soil in Rwanda should offer opportunities for paddy growing ( rice, etc, if soil fertility factors would be amended by lime for its

  13. RICE CULTIVATION ASPECTS OF DEVELOPMENT TIDAL SWAMPS AGRICULTURE SUPPORTED TO FOOD SECURITY (Case study of Danda Besar Unit, Barito Kuala district

    Directory of Open Access Journals (Sweden)

    Agus Supriyo

    2017-09-01

    Full Text Available k of reclamation. Research was carried out in July 2012. Method: "participatory rural appraisal" and interviews. Secondary data were obtained from "desk study". Data were analyzed using SWOT. Results: aspects of rice cultivating in land development tidal marsh consisting problem: (a land management (land arrangement lowland system start area upstream to downstream, low soil fertility, ground is not yet mature, (b arrangements water (macro and micro, (c participation of farmers (labor and skills are limited, and (d external support (KUD is not functioning optimally, number of extension limited to one PPL serves 659 farmers and "cover" area of land covering an area of 1,546 ha. Scenario development of tidal marsh Danda Besar can be divided into (a arrangement of land, (b setting micro water management by creating a channel quarter and channel worms and sanitation channel tertiary (c mechanization of agriculture by means of pre-harvest and post-harvest systems business services, training, technological innovation swamp land for farmer groups, and (d revitalizing function of cooperatives, increasing number of personnel PPLn and labor observers water associated with task forces village

  14. scale rice farmers in nigeria

    African Journals Online (AJOL)

    Admin

    of world rice, with China and India accounting for over half of the world's output. Worldwide, rice production has ... reported that rice indeed is no longer a luxury food in. Nigeria, and that it has become a major source of ... declined in China and Japan but this trend is not observed in other Asian countries; instead, the share ...

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

    Science.gov (United States)

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

    2014-12-01

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

  16. Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated ...

    African Journals Online (AJOL)

    Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated rice species from Ethiopia. ... African Journal of Biotechnology ... The genetic diversity of three wild rice populations of Ethiopia along with three cultivated rice populations were studied using Inter simple sequence repeats (ISSRs) as a molecular marker.

  17. Asia Rice Crop Estimation and Monitoring (Asia-RiCE) for GEOGLAM

    Science.gov (United States)

    Oyoshi, K.; Tomiyama, N.; Okumura, T.; Sobue, S.

    2013-12-01

    Food security is a critical issue for the international community because of rapid population and economic growth, and climate change. In June 2011, the meeting of G20 agriculture ministers was held to discuss food security and food price volatility, and they agreed on an 'Action Plan on Food Price Volatility and Agriculture'. This plan includes a GEO Global Agricultural Monitoring (GEOGLAM) initiative. The aim of GEOGLAM is to reinforce the international community's ability to produce and disseminate relevant, timely, and accurate forecasts of agricultural production on regional, national, and global scales by utilizing remote sensing technology. GEOGLAM focused on four major grain crops, wheat, maize, soybeans and rice. In particular, Asian countries are responsible for approximately 90% of the world rice production and consumption, rice is the most significant cereal crop in Asian region. Hence, Asian space and agricultural agencies with an interest in the development of rice crop monitoring technology launched an Asia-Rice Crop Estimation & Monitoring (Asia-RiCE) component for the GEOGLAM initiative. In Asian region, rice is mainly cultivated in rainy season, and a large amount of cloud limits rice crop monitoring with optical sensors. But, Synthetic Aperture RADAR (SAR) is all-weather sensor and can observe land surface even if the area is covered by cloud. Therefore, SAR technology would be powerful tool to monitor rice crop in Asian region. Asia-RiCE team required mainly SAR observation data including ALOS-2, RISAT-1, Sentinel-1 and RADARSAT, TerraSAR-X, COSMO-SkyMed for Asia-RiCE GEOGLAM Phase 1 implementation (2013-2015) to the Committee on Earth Observations (CEOS) in the GEOGLAM-CEOS Global Agricultural Monitoring Co-community Meeting held in June 2013. And also, rice crop has complicated cropping systems such as rein-fed or irrigated cultivation, single, double or sometimes triple cropping. In addition, each agricultural field is smaller than that of

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

    Science.gov (United States)

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

    2015-09-10

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

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

    Science.gov (United States)

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

    2011-01-01

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

  20. Growth, Metabolism and Yield of Rice Cultivated in Soils Amended with Fly Ash and Cyanobacteria and Metal Loads in Plant Parts

    OpenAIRE

    Padhy, Rabindra N.; Nayak, Nabakishore; Dash-Mohini, Rajesh R.; Rath, Shakti; Sahu, Rajani K

    2016-01-01

    Soil amendment with fly ash (FA) and combined supplementation with N2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grow...

  1. Impact of volunteer rice infestation on yield and grain quality of rice.

    Science.gov (United States)

    Singh, Vijay; Burgos, Nilda R; Singh, Shilpa; Gealy, David R; Gbur, Edward E; Caicedo, Ana L

    2017-03-01

    Volunteer rice (Oryza sativa L.) grains may differ in physicochemical traits from cultivated rice, which may reduce the quality of harvested rice grain. To evaluate the effect of volunteer rice on cultivated rice, fields were surveyed in Arkansas in 2012. Cropping history that included hybrid cultivars in the previous two years (2010 and 2011) had higher volunteer rice infestation (20%) compared with fields planted previously with inbred rice (5.5%). The total grain yield of rice was reduced by 0.4% for every 1% increase in volunteer rice density. The grain quality did not change in fields planted with the same cultivar for three years. Volunteer rice density of at least 7.6% negatively impacted the head rice and when infestation reached 17.7%, it also reduced the rice grain yield. The protein and amylose contents of rice were not affected until volunteer rice infestation exceeded 30%. Crop rotation systems that include hybrid rice are expected to have higher volunteer rice infestation than systems without hybrid rice. It is predicted that, at 8% infestation, volunteer rice will start to impact head rice yield and will reduce total yield at 18% infestation. It could alter the chemical quality of rice grain at >30% infestation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. The Emissions of Carbon Dioxide, Methane, and Nitrous Oxide during Winter without Cultivation in Local Saline-Alkali Rice and Maize Fields in Northeast China

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-10-01

    Full Text Available Agricultural ecosystems are important contributors to atmospheric greenhouse gasses (GHGs; however, in situ winter emission data in saline-alkali fields are scarce. Gas samples were collected during different periods, from three rice (R1–R3 and three maize (M1–M3 fields with different soil pH levels and salinity conditions. Carbon dioxide (CO2 emissions in the rice and maize fields decreased with decreasing temperature during the freezing period and increased with the rising temperature during the thawing period, with the majority of winter CO2 emissions occurring during these two periods. Peaks in methane (CH4 emissions were observed during the freezing period in the rice fields and during the snow-melting period in the rice and maize fields. CH4 emissions in the rice fields and CH4 uptake rates in the maize fields were significantly (P < 0.05 related to surface soil temperature. Nitrous oxide (N2O emissions remained relatively low, except for during the peaks observed during the snow-melting period in both the rice and maize fields, leading to the high GHG contribution of the snow-melting period throughout the winter. Higher pH and salinity conditions consistently resulted in lower CO2, CH4, and N2O emissions, CH4 uptake, and lower global warming potential (GWP. These results can contribute to the assessment of the GWP during winter in saline-alkali regions.

  3. FLUORIDE LEVELS IN COMMERCIALLY AVAILABLE RICE IN ...

    African Journals Online (AJOL)

    Preferred Customer

    2013-05-05

    May 5, 2013 ... shattering-prone Oryza glaberrima. It contains 2% more protein than their African or Asian parents. It is taller than most rice, making harvesting easier, pest resistant and tolerant to drought and infertile soils better than Asian varieties [18]. Rice is a cereal foodstuff which forms an important part of the diet of ...

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

    Directory of Open Access Journals (Sweden)

    Katherine E. Wilkins

    2015-07-01

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

  5. 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.

  6. Saving water? : analysis of options for rice-based farms in Tamil Nadu, India

    NARCIS (Netherlands)

    Senthilkumar, K.

    2008-01-01

    Keywords: Modified rice cultivation, Water-saving, Farm typology, Technology adoption, Policy interventions, Farmers livelihoods, Resource use efficiency and Linear programming. The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative management

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

    Science.gov (United States)

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

    2014-09-01

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

  8. Selective sweep with significant positive selection serves as the driving force for the differentiation of japonica and indica rice cultivars.

    Science.gov (United States)

    Yuan, Yang; Zhang, Qijun; Zeng, Shuiyun; Gu, Longjiang; Si, Weina; Zhang, Xiaohui; Tian, Dacheng; Yang, Sihai; Wang, Long

    2017-04-19

    Asian cultivated rice (Oryza sativa L.), including japonica and indica, is unarguable the most important crop in Asia as well as worldwide. However, a decisive conclusion of its origination and domestication processes are still lacking. Nowadays, the ever-increasing high-throughput sequencing data of numerous rice samples have provided us new opportunities to get close to the answer of these questions. By compiling 296 whole-genome sequenced rice cultivars and 39 diverse wild rice, two types of domesticated regions (DR-I and DR-II) with strong selective sweep signals between different groups were detected. DR-I regions included 28 blocks which significantly differentiated between japonica and indica subspecies, while DR-II regions were consisted of another 28 blocks which significantly differentiated between wild and cultivated rice, each covered 890 kb and 640 kb, respectively. In-depth analysis suggested that both DR-Is and DR-IIs could have originated from Indo-China Peninsula to southern China, and DR-IIs might be introgressed from indica to japonica. Functional bias with significant positive selection has also been detected in the genes of DR-I, suggesting important role of the selective sweep in differentiation of japonica and indica. This research promoted a new possible model of the origin of the cultivated rice that DR-Is in japonica and indica maybe independently originated from the divergent wild rice in the Indo-China Peninsula to southern China, and then followed by frequent introgression. Genes with significant positive selection and biased functions were also detected which could play important roles in rice domestication and differentiation processes.

  9. Dispersal distance of rice (Oryza Sativa L.) pollen at the Tana River ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... chances of gene flow from transgenic rice to conventional or wild rices. Key words: Pollen dispersal, gene ... However, cultivation of GM rice may have agronomic and environmental ..... Taxonomy of Zea (Gramineae). I. A sub-.

  10. Quantitative and qualitative damage caused by Oebalus poecilus (Hemiptera, Pentatomidae to upland rice cultivated in new agricultural frontier of the Amazon rainforest (Brazil

    Directory of Open Access Journals (Sweden)

    Diones Krinski

    Full Text Available ABSTRACT Oebalus poecilus (Dallas 1851 is one of the stink bug species of great economic importance for rice producers in Brazil of irrigated, flood and upland cropping systems. These pentatomids are known as stink bugs of panicles, because both nymphs and adults feed mainly on panicles. Stink bug attacks result in pecky (spots seeds, lower mass, germinative reduction and deformed grains. Bearing these factors in mind, the aim of this study was to evaluate the quantitative and qualitative losses in commercial cultivars of upland rice (Cambará variety, submitted to different population levels of stink bugs of panicles, O. poecilus, at different reproductive growth stages. The results show that in upland rice (Cambará variety, the rice grains are susceptible to quantitative (number and weight and qualitative (pecky, atrophy, chalky and broken grains damage during all panicle development. However, when the insects feed during anthesis/caryopsis and milky stage cause significantly greater percentage of empty grains (up to 83% than when they feed of grains during later phases of panicle development. This characteristic was also observed for the reduction in grain weight. This information may benefit producers and other researchers, allowing them to focus on the monitoring efforts of O. poecilus in most susceptible phases of the attack of this insect. This will enable decision-making about what control measures should be taken, and when, in order to control stink bugs of panicles.

  11. 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

  12. Biochar amendment reduced methylmercury accumulation in rice plants

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Rui; Wang, Yongjie [School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People’s Republic of China (China); Zhong, Huan, E-mail: zhonghuan@nju.edu.cn [School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, People’s Republic of China (China); Environmental and Life Sciences Program (EnLS), Trent University, Peterborough, Ontario (Canada)

    2016-08-05

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

  13. 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...

  14. Tracing ancestor rice of Suriname Maroons back to its African origin.

    Science.gov (United States)

    van Andel, Tinde R; Meyer, Rachel S; Aflitos, Saulo A; Carney, Judith A; Veltman, Margaretha A; Copetti, Dario; Flowers, Jonathan M; Havinga, Reinout M; Maat, Harro; Purugganan, Michael D; Wing, Rod A; Schranz, M Eric

    2016-10-03

    African rice (Oryza glaberrima) and African cultivation practices are said to have influenced emerging colonial plantation economies in the Americas(1,2). However, the level of impact of African rice practices is difficult to establish because of limited written or botanical records(2,3). Recent findings of O. glaberrima in rice fields of Suriname Maroons bear evidence of the high level of knowledge about rice among African slaves and their descendants, who consecrate it in ancestor rituals(4,5). Here we establish the strong similarity, and hence likely origin, of the first extant New World landrace of O. glaberrima to landraces from the Upper Guinean forests in West Africa. We collected African rice from a Maroon market in Paramaribo, Suriname, propagated it, sequenced its genome(6) and compared it with genomes of 109 accessions representing O. glaberrima diversity across West Africa. By analysing 1,649,769 single nucleotide polymorphisms (SNPs) in clustering analyses, the Suriname sample appears sister to an Ivory Coast landrace, and shows no evidence of introgression from Asian rice. Whereas the Dutch took most slaves from Ghana, Benin and Central Africa(7), the diaries of slave ship captains record the purchase of food for provisions when sailing along the West African Coast(8), offering one possible explanation for the patterns of genetic similarity. This study demonstrates the utility of genomics in understanding the largely unwritten histories of crop cultures of diaspora communities.

  15. Cultivable Methylobacterium species diversity in rice seeds identified with whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis.

    Science.gov (United States)

    Okumura, Marie; Fujitani, Yoshiko; Maekawa, Masahiko; Charoenpanich, Jittima; Murage, Hunja; Kimbara, Kazuhide; Sahin, Nurettin; Tani, Akio

    2017-02-01

    Methylobacterium species are methylotrophic bacteria that widely inhabit plant surfaces. In addition to studies on methylotrophs as model organisms, research has also been conducted on their mechanism of plant growth promotion as well as the species-species specificity of plant-microbe interaction. We employed whole-cell matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (WC-MS) analysis, which enables the rapid and accurate identification of bacteria at the species level, to identify Methylobacterium isolates collected from the rice seeds of different cultivars harvested in Japan, Thailand, and Kenya. Rice seeds obtained from diverse geographical locations showed different communities of Methylobacterium species. We found that M. fujisawaense, M. aquaticum, M. platani, and M. radiotolerans are the most frequently isolated species, but none were isolated as common species from 18 seed samples due to the highly biased communities in some samples. These findings will contribute to the development of formulations containing selected species that promote rice growth, though it may be necessary to customize the formulations depending on the cultivars and farm conditions. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Monitoring Changes in Rice Cultivated Area from SAR and Optical Satellite Images in Ben Tre and Tra Vinh Provinces in Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Kirsi Karila

    2014-05-01

    Full Text Available The objective of this study was to obtain up-to-date information on land use and to identify long term changes in land use, especially rice, aquaculture and other crops in Ben Tre and Tra Vinh provinces in Vietnam’s Mekong Delta. Long-term changes in land-use of the study area have not been studied using long time series of SAR and optical Earth observation (EO data before. EO data from 1979–2012 was used: ENVISAT ASAR Wide Swath Mode, SPOT and Landsat imagery. An unsupervised ISODATA classification was performed on multitemporal SAR images. The results were validated using ground truth data. Using the Synthetic Aperture Radar (SAR imagery maps for 2005, 2009 and 2011 were obtained. Different rice crops, aquaculture and fruit trees could be distinguished with an overall accuracy of 80%. Using available optical imagery the time series was extended from 2005 to 1979. Long-term decrease in the rice acreage and increase in the aquaculture acreage could be detected.

  17. Growth, Metabolism and Yield of Rice Cultivated in Soils Amended with Fly Ash and Cyanobacteria and Metal Loads in Plant Parts

    Directory of Open Access Journals (Sweden)

    Rabindra N. Padhy

    2016-01-01

    Full Text Available Soil amendment with fly ash (FA and combined supplementation with N2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grown at FA level 4.0 kg/m2. Basic soil properties, pH value, percentage of silt, percentage of clay, water-holding capacity, electrical conductivity, cation exchange capacity, and organic carbon content increased due to the FA amendment. Parallel supplementation of FA amended plots with 1.0 kg/m2 N2-fixing cyanobacteria mass caused further significant increments of the most soil properties, and rice growth and yield parameters. 1000-grain weight of rice plants grown at FA level 4.0 kg/m2 along with cyanobacteria supplementation was the maximum. Cyanobacteria supplementation caused increase of important basic properties of soil including the total N-content. Estimations of elemental content in soils and plant parts (root and seed were done by the atomic absorption spectrophotometry. Accumulations of K, P, Fe and several plant micronutrients (Mn, Ni, Co, Zn and Cu and toxic elements (Pb, Cr and Cd increased in soils and plant parts as a function of the FA gradation, but Na content remained almost unchanged in soils and seeds. Supplementation of cyanobacteria had ameliorating effect on toxic metal contents of soils and plant parts. The FA level 4.0 kg/m2, with 1.0 kg/m2 cyanobacteria mass supplementation, could be taken ideal, since there would be recharging of the soil with essential micronutrients as well as toxic chemicals in comparative lesser proportions, and cyanobacteria mass would cause lessening toxic metal loads with usual N2-fixation.

  18. Effect of volunteer rice infestation on grain quality and yield of rice

    Science.gov (United States)

    Volunteer rice (Oryza sativa L.) plants arise from shattered seeds of the previous crop, which could reduce the yield of cultivated rice and the commercial value of harvested grain. Volunteer rice plants from a cultivar other than the current crop produce grains that may differ in physico-chemical t...

  19. Produtividade, fitotoxicidade e controle de arroz-vermelho na sucessão de cultivo de arroz irrigado no Sistema CLEARFIELD® Productivity, injury and control of red rice in succession of irrigated rice cultivation in System CLEARFIELD®

    Directory of Open Access Journals (Sweden)

    Enio Marchesan

    2011-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o sistema CLEARFIELD® quanto ao controle do arroz-vermelho, influência sobre a produtividade, bem como a fitotoxicidade ocasionada pelo possível residual no solo da mistura formulada de imazethapyr e imazapic em genótipo de arroz tolerante (IRGA 422CL e não-tolerante (IRGA 417, os quais serviram como plantas indicadoras. O delineamento experimental foi de blocos ao acaso em esquema bifatorial (4x3 com parcelas subdivididas, sendo as parcelas principais representadas pela rotação entre arroz tolerante (IRGA 422CL e o arroz não-tolerante a imidazolinonas (IRGA 417. Nas sub-parcelas foram aplicados os tratamentos para o controle de arroz-vermelho em diferentes épocas de aplicação (pós-emergência (V4, pré+ pós emergência (no dia da semeadura + V4. A fitotoxicidade foi caracterizada com base na cor das folhas, largura, crescimento e desenvolvimento do limbo foliar. Observou-se que a fitotoxicidade foi maior quando o herbicida foi aplicado em pós-emergência permanecendo seus efeitos até 383 dias após a aplicação. O controle de arroz-vermelho não é eficiente com a utilização de apenas um ano agrícola do sistema CLEARFIELD® e o melhor nível de controle e produtividade foi obtido após dois ou três anos consecutivos desse sistema.The objective of this study was to evaluate the CLEARFIELD ® system regarding the control of red rice, influences on productivity, as well as the possible phytotoxicity caused by carryover soil formulated mixture of imazethapyr and imazapic in tolerant rice genotype (IRGA 422CL and non-tolerant (IRGA 417, which served as indicator plants. The experimental design was randomized blocks in a factorial scheme (4x3 with subplots, the main plots represented by rotating tolerant rice (IRGA 422CL and rice not tolerant to imidazolinone (IRGA 417. In sub-plot treatments were applied to control red rice in different stages of the post-emergence (V4, pre + post emergence

  20. 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.

  1. Extensive sequence divergence between the reference genomes of two elite indica rice varieties Zhenshan 97 and Minghui 63.

    Science.gov (United States)

    Zhang, Jianwei; Chen, Ling-Ling; Xing, Feng; Kudrna, David A; Yao, Wen; Copetti, Dario; Mu, Ting; Li, Weiming; Song, Jia-Ming; Xie, Weibo; Lee, Seunghee; Talag, Jayson; Shao, Lin; An, Yue; Zhang, Chun-Liu; Ouyang, Yidan; Sun, Shuai; Jiao, Wen-Biao; Lv, Fang; Du, Bogu; Luo, Meizhong; Maldonado, Carlos Ernesto; Goicoechea, Jose Luis; Xiong, Lizhong; Wu, Changyin; Xing, Yongzhong; Zhou, Dao-Xiu; Yu, Sibin; Zhao, Yu; Wang, Gongwei; Yu, Yeisoo; Luo, Yijie; Zhou, Zhi-Wei; Hurtado, Beatriz Elena Padilla; Danowitz, Ann; Wing, Rod A; Zhang, Qifa

    2016-08-30

    Asian cultivated rice consists of two subspecies: Oryza sativa subsp. indica and O. sativa subsp. japonica Despite the fact that indica rice accounts for over 70% of total rice production worldwide and is genetically much more diverse, a high-quality reference genome for indica rice has yet to be published. We conducted map-based sequencing of two indica rice lines, Zhenshan 97 (ZS97) and Minghui 63 (MH63), which represent the two major varietal groups of the indica subspecies and are the parents of an elite Chinese hybrid. The genome sequences were assembled into 237 (ZS97) and 181 (MH63) contigs, with an accuracy >99.99%, and covered 90.6% and 93.2% of their estimated genome sizes. Comparative analyses of these two indica genomes uncovered surprising structural differences, especially with respect to inversions, translocations, presence/absence variations, and segmental duplications. Approximately 42% of nontransposable element related genes were identical between the two genomes. Transcriptome analysis of three tissues showed that 1,059-2,217 more genes were expressed in the hybrid than in the parents and that the expressed genes in the hybrid were much more diverse due to their divergence between the parental genomes. The public availability of two high-quality reference genomes for the indica subspecies of rice will have large-ranging implications for plant biology and crop genetic improvement.

  2. Molecular and cultivation-dependent analysis of metal-reducing bacteria implicated in arsenic mobilisation in south-east asian aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Hery, Marina; Gault, Andrew G.; Rowland, Helen A.L.; Lear, Gavin; Polya, David A. [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom); Lloyd, Jonathan R. [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom)], E-mail: jon.lloyd@manchester.ac.uk

    2008-11-15

    The reduction of sorbed As(V) to the potentially more mobile As(III) by As-respiring anaerobic bacteria has been implicated in the mobilisation of the toxic metalloid in aquifer sediments in SE Asia. However, there is currently only a limited amount of information on the identity of the organisms that can respire As(V) in these sediment systems. Here experiments are described that have targeted As(V)-respiring bacteria using cultivation-independent molecular techniques, and also more traditional microbiological approaches that have used growth media highly selective for organisms that can grow using arsenate as the sole electron acceptor supplied for anaerobic growth. The molecular techniques used have initially targeted DNA from microcosms displaying maximal rates of arsenate reduction, both with and without added electron donor. More recent studies from the authors' laboratory have used stable isotope probing techniques, targeting DNA from the active microbial fraction in microcosms labelled with [{sup 13}C]acetate supplied as an electron donor for arsenate reduction. Phylogenetic analyses using a highly conserved genetic marker (the 16S rRNA gene) have suggested the involvement of Sulfurospirillum and Geobacter species in arsenate-respiration, and this has been supported further by complimentary experiments using more traditional microbiological techniques. Additional research required to clarify the role of these organisms in the mobilisation of As in situ are discussed.

  3. 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.

  4. Wheat products as acceptable substitutes for rice.

    Science.gov (United States)

    Yu, B H; Kies, C

    1993-07-01

    The objective of the study was to compare the acceptability to semi-trained US American and Asian palatability panelist, of four wheat products processed to be possible replacers of rice in human diets. Products evaluated using rice as the control standard of excellence were steamed whole wheat, couscous (steamed, extracted wheat flour semolina), rosamarina (rice shaped, extracted wheat flour pasta), and bulgar (steamed, pre-cooked partly debranned, cracked wheat). Using a ten point hedonic rating scale, both groups of panelists gave rosamarina closely followed by couscous, most favorable ratings although these ratings were somewhat lower than that of the positive control, steamed polished rice. Bulgar wheat was given the lowest evaluation and was, in general, found to be an unacceptable replacement for rice by both American and Asian judges because of its dark, 'greasy' color and distinctive flavor. In their personal dietaries, judges included rice from 0.25 to 18 times per week with the Asian judges consuming rice significantly more times per week than did the American judges (10.8 +/- 4.71 vs 1.75 +/- 1.65, p < 0.01). However, rice consumption patterns, nationality, race, or sex of the judges was not demonstrated to affect scoring of the wheat products as rice replacers.

  5. Global Rice Atlas: Disaggregated seasonal crop calendar and production

    NARCIS (Netherlands)

    Balanza, Jane Girly; Gutierrez, Mary Anne; Villano, Lorena; Nelson, A.D.; Zwart, S.J.; Boschetti, Mirco; Koo, Jawoo; Reinke, Russell; Murty, M. V.R.; Laborte, Alice G.

    2014-01-01

    Purpose: Rice is an important staple crop cultivated in more than 163 million ha globally. Although information on the distribution of global rice production is available by country and, at times, at subnational level, information on its distribution within a year is often lacking in different rice

  6. Rice crop growth and outlook monitoring using SAR in Asia

    Science.gov (United States)

    Hamamoto, K.; Sobue, S.; Oyoshi, K.; Ikehata, Y.

    2016-12-01

    The Asia-RiCE initiative (http://www.asia-rice.org) has been organized to enhance rice production estimates through the use of Earth observation satellites data, and seeks to ensure that Asian rice crops are appropriately represented within GEO Global Agriculture Monitoring (GEO-GLAM) to support FAO Agriculture Market Information System (FAO-AMIS). Asia-RiCE is composed of national teams that are actively contributing to the Crop Monitor for AMIS and developing technical demonstrations of rice crop monitoring activities using both Synthetic Aperture Radar (SAR) data (Radarsat-2 from 2013; Sentinel-1 and ALOS-2 from 2015; TerraSAR-X, Cosmo-SkyMed, RISAT, and others) and optical imagery (such as from MODIS, SPOT-5, Landsat, and Sentinel-2) for 100x100km Technical Demonstration Sites (TDS) as a phase 1 (2013-2015) in Asia. with satellite -based cultivated area and growing stage map. The Asia-RiCE teams are also developing satellite-based agro-met information for rice crop outlook, crop calendars and damage assessment in cooperation with ASEAN food security information system (AFSIS) for selected countries (currently Indonesia, Thailand, Vietnam, Philippine, and Japan; http://www.afsisnc.org/blog), using JAXA's Satellite-based MonItoring Network system as a contribution to the FAO AMIS outlook (JASMIN) with University of Tokyo (http://suzaku.eorc.jaxa.jp/cgi-bin/gcomw/jasm/jasm_top.cgi). Because of continous El Nino in South East Asia, there are less precipitation and rain fall pattern change in South East Asia, crop pattern has been changed and production may be decreased, especially for dry season crop. JAXA provides drought index (KBDI) and accumulated precipitation of Tak province, Thailand where main reservior is located, to AFSIS and national experts to assess rice crop outlook and NDVI time seriese to Ang Tong province where is main rice production area in downstream area of that reservior.From 2016 as a phase 2, Asia-RiCE initiative deploy up-scaling activity

  7. Evaluation of effectiveness of seed priming with selenium in rice during germination under arsenic stress.

    Science.gov (United States)

    Moulick, Debojyoti; Ghosh, Dibakar; Chandra Santra, Subhas

    2016-12-01

    Due to extensive use of arsenic (As) contaminated ground water in rice cultivation As toxicity has become a growing concern to rice growers of south east Asian countries. The presence of As in soil and irrigation water causes impaired crop growth and development. Selenium (Se) at lower concentration (1.0 mg L-1) is reported to be stimulatory on crop growth and it has also an antagonistic behavior with As. With this rationale the present study was conducted to investigate into the potentiality of seed priming technology with Se to ameliorate the As stress on rice seed germination and seedling growth. The seed germination percentage, seedling growth, total phenolics, proline and malonaldehyde content as well as total As uptake pattern of rice seedlings grown under As stressed condition were measured. The As induced toxicity markedly reduced the germination percentage by 70%, whereas, Se supplementation through seed priming enhanced the rice seed germination by 9% and root and shoot length vis-a-vis seedling biomass accumulation by 1.3, 1.6 and 1.4 fold respectively. The inhibitory effect of As stress was more on root growth than that of shoot. The toxicity due to arsenite stress was higher than the arsenate stress. Seed priming with Se enhanced seed germination and seedling growth by reducing As uptake, suppressing the oxidative damage through increase in antioxidants accumulation in rice seedlings. Seed primed with 0.8 mg Se L-1 was more effective in improving rice seed germination and seedling growth, compared to 1.0 mg Se L-1. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Origin of rice (Oryza sativa L.) domestication genes

    OpenAIRE

    Civ??, Peter; Brown, Terence A.

    2017-01-01

    A number of genes that contribute to the domestication traits of cultivated rice have been identified. These include Sh4, Rc, PROG1 and LABA1, which are associated with non-shattering rachis, white pericarp, erect growth and barbless awns, respectively. The mutations giving rise to the ?domestication alleles? of these genes are either invariable in cultivated rice, or have variability that is strictly associated with the phenotypic trait. This observation forms the basis to those current rice...

  9. Tolerance to zinc deficiency in rice correlates with zinc uptake and translocation

    NARCIS (Netherlands)

    Gao, X.; Zou, C.Q.; Zee, van der S.E.A.T.M.; Hoffland, E.

    2005-01-01

    To study variation in zinc efficiency (ZE) among current Chinese rice genotypes, a pot experiment was conducted with 15 aerobic and 8 lowland rice genotypes. Aerobic rice is currently bred by crossing lowland with upland rice genotypes, for growth in an aerobic cultivation system, which is saving

  10. Can herbicide safeners allow selective control of weedy rice infesting rice crops?

    Science.gov (United States)

    Busi, Roberto; Nguyen, Nghia K; Chauhan, Bhagirath S; Vidotto, Francesco; Tabacchi, Maurizio; Powles, Stephen B

    2017-01-01

    Rice is a major field crop of paramount importance for global food security. However, the increased adoption of more profitable and resource-efficient direct-seeded rice (DSR) systems has contributed to greater weed infestations, including weedy rice, which has become a severe problem in several Asian regions. In this study we have developed a conceptually novel method to protect rice plants at high doses of clomazone and triallate. The insecticide phorate applied to rice seeds provided a substantial level of protection against the herbicides clomazone or triallate. A quantity of 15 kg phorate ha(-1) significantly increased the LD50 values, which were more than twofold greater than for rice plants treated only with clomazone. A quantity of 20 kg phorate ha(-1) in combination with 2000 g triallate ha(-1) safened rice plants (80% survival) with LD50 >3.4-fold greater than in phorate-untreated rice. Weed control efficacy was not lowered by the presence of phorate-treated rice seeds. Weedy rice is one of the most damaging global weeds and a major threat to DSR systems. In this study we have developed a proof-of-concept method to allow selective weedy rice control in rice crops. We call for herbicide discovery programmes and research to identify candidate safener and herbicide combinations to achieve selective herbicide control of weedy rice and alleviate weed infestations in global rice crops. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. A single-nucleotide polymorphism causes smaller grain size and loss of seed shattering during African rice domestication.

    Science.gov (United States)

    Wu, Wenguang; Liu, Xiaoyun; Wang, Muhua; Meyer, Rachel S; Luo, Xiaojin; Ndjiondjop, Marie-Noelle; Tan, Lubin; Zhang, Jianwei; Wu, Jianzhong; Cai, Hongwei; Sun, Chuanqing; Wang, Xiangkun; Wing, Rod A; Zhu, Zuofeng

    2017-05-08

    Grain size is one of the most important components of grain yield and selecting large seeds has been a main target during plant domestication. Surprisingly, the grain of African cultivated rice (Oryza glaberrima Steud.) typically is smaller than that of its progenitor, Oryza barthii. Here we report the cloning and characterization of a quantitative trait locus, GL4, controlling the grain length on chromosome 4 in African rice, which regulates longitudinal cell elongation of the outer and inner glumes. Interestingly, GL4 also controls the seed shattering phenotype like its orthologue SH4 gene in Asian rice. Our data show that a single-nucleotide polymorphism (SNP) mutation in the GL4 gene resulted in a premature stop codon and led to small seeds and loss of seed shattering during African rice domestication. These results provide new insights into diverse domestication practices in African rice, and also pave the way for enhancing crop yield to meeting the challenge of cereal demand in West Africa.

  12. 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.

  13. Técnicas de cultivo de arroz irrigado: relação com a qualidade de água, protozoários e diversidade fitoplanctônica Irrigated rice cultivation techniques: relationship between water quality, protozoa and phytoplanktonic diversity

    Directory of Open Access Journals (Sweden)

    Ricardo D. Furtado

    2003-04-01

    Full Text Available O efeito de técnicas de cultivo do arroz irrigado sobre a qualidade da água efluente foi avaliado através de parâmetros físicos, químicos e biológicos. A pesquisa foi desenvolvida na Estação Experimental do Instituto Riograndense do Arroz (IRGA no município de Cachoeirinha, RS, bacia do Rio Gravataí. Os testes foram realizados com 3 técnicas distintas e usuais de plantio: convencional, pré-germinado e direto. Constatou-se que, nos primeiros 30 dias de irrigação, os parâmetros medidos dentro dos quadros de plantio apresentaram valores superiores aos da entrada; após este período, a situação se inverteu. Com o crescimento, as plantas de arroz funcionaram como um banhado natural, extraindo da água e do solo uma quantidade significativa de nutrientes, não somente durante sua fase inicial, mas, também, durante todo o seu ciclo. Esses nutrientes foram extraídos do meio líquido, melhorando a qualidade ambiental da água efluente. Dentre todas as técnicas de cultivo, o menor impacto sobre a qualidade da água foi apresentado pelo plantio direto.The purpose of this study was to evaluate the effect of techniques of rice cultivation on the physical, chemical and biological parameters of effluent water. The research was conducted at the Experimental Station of IRGA (Rio Grande do Sul Rice Institute, in the municipality of Cachoeirinha, RS, in the Gravataí river basin. The tests were performed using 3 usual techniques of rice cultivation, conventional, pre-germinated and direct planting. During the first 30 days of irrigation, the physical and chemical parameters of the paddy fields presented higher values compared to that of inflow. This shows that during this period the impact on water quality was highest. After this period, the situation changed completely. After reaching adult size, the rice plants acted as a natural swamp, extracting most of the contaminants from the water and the soil until the harvest. Thus the impact of

  14. 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.

  15. Impacts of climate change on paddy rice yield in a temperate climate.

    Science.gov (United States)

    Kim, Han-Yong; Ko, Jonghan; Kang, Suchel; Tenhunen, John

    2013-02-01

    The crop simulation model is a suitable tool for evaluating the potential impacts of climate change on crop production and on the environment. This study investigates the effects of climate change on paddy rice production in the temperate climate regions under the East Asian monsoon system using the CERES-Rice 4.0 crop simulation model. This model was first calibrated and validated for crop production under elevated CO2 and various temperature conditions. Data were obtained from experiments performed using a temperature gradient field chamber (TGFC) with a CO2 enrichment system installed at Chonnam National University in Gwangju, Korea in 2009 and 2010. Based on the empirical calibration and validation, the model was applied to deliver a simulated forecast of paddy rice production for the region, as well as for the other Japonica rice growing regions in East Asia, projecting for years 2050 and 2100. In these climate change projection simulations in Gwangju, Korea, the yield increases (+12.6 and + 22.0%) due to CO2 elevation were adjusted according to temperature increases showing variation dependent upon the cultivars, which resulted in significant yield decreases (-22.1% and -35.0%). The projected yields were determined to increase as latitude increases due to reduced temperature effects, showing the highest increase for any of the study locations (+24%) in Harbin, China. It appears that the potential negative impact on crop production may be mediated by appropriate cultivar selection and cultivation changes such as alteration of the planting date. Results reported in this study using the CERES-Rice 4.0 model demonstrate the promising potential for its further application in simulating the impacts of climate change on rice production from a local to a regional scale under the monsoon climate system. © 2012 Blackwell Publishing Ltd.

  16. Studies on the Ecological Adaptability of Growing Rice with Floating Bed on the Dilute Biogas Slurry

    Directory of Open Access Journals (Sweden)

    Qun Kang

    2016-01-01

    Full Text Available This study aimed to explore the ecological adaptability and the possibility of growing rice with floating bed on the dilute biogas slurry. The results of the experiments show that the growth stage, rice plant height, and rice yield and quality were significantly affected by multiple dilutions; rice plants cultivated with 45 multiple dilutions had better ecological adaptability than others. In the 45 multiple dilutions’ group, the yield of rice was 13.3 g/bucket (8 rice plants, milled rice rate was 63.1%, and the content of crude protein in the rice was 6.3%. The concentrations of heavy metals in the rice cultivated with 30 multiple dilutions’ slurry, such as total lead, cadmium, mercury, chromium, and arsenic, were all below the national standard. The study shows that it is possible and safe to cultivate rice plants with no soil but diluted biogas slurry. In the experiments, the yield, milled rice rate, and crude protein of the rice cultivated with slurry were not as much as those of rice cultivated with regular way in soil. This study provides the basic theoretical support for the development of biogas projects and the potential achievement of organic farming in special agricultural facilities and circular economy.

  17. Studies on the Ecological Adaptability of Growing Rice with Floating Bed on the Dilute Biogas Slurry

    Science.gov (United States)

    Du, Qi; Cheng, Bowen; Liao, Zhiqi; Sun, Chengcheng

    2016-01-01

    This study aimed to explore the ecological adaptability and the possibility of growing rice with floating bed on the dilute biogas slurry. The results of the experiments show that the growth stage, rice plant height, and rice yield and quality were significantly affected by multiple dilutions; rice plants cultivated with 45 multiple dilutions had better ecological adaptability than others. In the 45 multiple dilutions' group, the yield of rice was 13.3 g/bucket (8 rice plants), milled rice rate was 63.1%, and the content of crude protein in the rice was 6.3%. The concentrations of heavy metals in the rice cultivated with 30 multiple dilutions' slurry, such as total lead, cadmium, mercury, chromium, and arsenic, were all below the national standard. The study shows that it is possible and safe to cultivate rice plants with no soil but diluted biogas slurry. In the experiments, the yield, milled rice rate, and crude protein of the rice cultivated with slurry were not as much as those of rice cultivated with regular way in soil. This study provides the basic theoretical support for the development of biogas projects and the potential achievement of organic farming in special agricultural facilities and circular economy. PMID:27882324

  18. Diabetes in Asians

    Directory of Open Access Journals (Sweden)

    Eun-Jung Rhee

    2015-09-01

    Full Text Available The prevalence of diabetes is increasing globally, particularly in Asia. According to the 2013 Diabetes Atlas, an estimated 366 million people are affected by diabetes worldwide; 36% of those affected live in the Western Pacific region, with a significant proportion in East Asia. The reasons for this marked increase in the prevalence of diabetes can be extrapolated from several distinct features of the Asian region. First, the two most populated countries, China and India, are located in Asia. Second, Asians have experienced extremely rapid economic growth, including rapid changes in dietary patterns, during the past decades. As a result, Asians tend to have more visceral fat within the same body mass index range compared with Westerners. In addition, increased insulin resistance relative to reduced insulin secretory function is another important feature of Asian individuals with diabetes. Young age of disease onset is also a distinctive characteristic of these patients. Moreover, changing dietary patterns, such as increased consumption of white rice and processed red meat, contributes to the deteriorated lifestyle of this region. Recent studies suggest a distinctive responsiveness to novel anti-diabetic agents in Asia; however, further research and efforts to reverse the increasing prevalence of diabetes are needed worldwide.

  19. African Rice in the History of the New World

    Directory of Open Access Journals (Sweden)

    Judith Carney

    2017-09-01

    Full Text Available Rice was introduced to multiple regions of the Americas during the colonial period. Rice plantations flourished in the U.S. southeast and eighteenth-century Brazil. Long attributed to European initiative, recent scholarship suggests that enslaved Africans provided more than labor to the emergence of rice as a food crop in the western hemisphere. This emerges from scholarly consensus that rice was independently domesticated in West Africa 3,000 years ago and further recognition of its role as provisions on transatlantic slave ships. This article summarizes the research findings in support of African agency in New World rice cultivation. A comparative historical approach to Atlantic rice culture suggests African cultural antecedents. The discussion examines the role of enslaved rice-growing Africans in transferring the seed and cultivation skills critical for pioneering the crop’s establishment in the Americas.

  20. Plant growth and cultivation.

    Science.gov (United States)

    Podar, Dorina

    2013-01-01

    There is a variety of methods used for growing plants indoor for laboratory research. In most cases plant research requires germination and growth of plants. Often, people have adapted plant cultivation protocols to the conditions and materials at hand in their own laboratory and growth facilities. Here I will provide a guide for growing some of the most frequently used plant species for research, i.e., Arabidopsis thaliana, barley (Hordeum vulgare) and rice (Oryza sativa). However, the methods presented can be used for other plant species as well, especially if they are related to the above-mentioned species. The presented methods include growing plants in soil, hydroponics, and in vitro on plates. This guide is intended as a starting point for those who are just beginning to work on any of the above-mentioned plant species. Methods presented are to be taken as suggestive and modification can be made according to the conditions existing in the host laboratory.

  1. Cultivation of oyster mushroom ( Pleurotus spp.) on palm oil ...

    African Journals Online (AJOL)

    Oyster mushroom is a popular mushroom due to its nutritional, medicinal and potential commercial value. In Malaysia, the fungus is currently cultivated on sawdust and rice husk. In this study, the efficiency of cultivating oyster mushroom was assessed using palm oil mesocarp fibre as a substrate. The experiment consisted ...

  2. Assessment of cultivated and wild, weedy rice lines to concurrent changes in CO2 concentration and air temperature: Determining traits for enhanced seed yield with increasing atmospheric CO2

    Science.gov (United States)

    Although a number of studies have examined intra-specific variability in growth and yield to projected atmospheric CO2 concentration, [CO2], none have compared the relative responses of cultivated and wild, weedy crop lines. We quantified the growth and seed yield response for three cultivated ("44...

  3. Interação entre silício e nitrogênio em arroz cultivado sob solução nutritiva Silicon-nitrogen interaction in rice cultivated under nutrient solution

    Directory of Open Access Journals (Sweden)

    Fabrício William Ávila

    2010-06-01

    Full Text Available O presente estudo objetivou avaliar o efeito da interação entre silício e nitrogênio nos teores de clorofila, nitrato, amônio e nitrogênio total, na produção de biomassa e nos números de perfilhos e de panículas em arroz cultivado em solução nutritiva. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 5 x 2, sendo duas concentrações de silício (0 e 50 mg L-1 e cinco as de nitrogênio (20; 50; 100; 200 e 400 mg L-1, com três repetições. No estádio de formação do colar da folha bandeira foram realizadas a leitura SPAD e as determinações dos teores de clorofila a e b, nitrogênio nítrico, amoniacal e total. No estádio de maturidade completa da panícula, foram avaliados os números de perfilhos e de panículas e determinaram-se os pesos de matéria seca de raiz e parte aérea e o acúmulo de silício na planta. Os resultados mostraram que o fornecimento de silício não alterou o perfilhamento, a produção de matéria seca e os teores de nitrogênio total. O silício elevou os valores SPAD, os teores de clorofila a e b, os teores de nitrato nas raízes e o número de panículas, especialmente em doses elevadas de nitrogênio.The present study aimed to evaluate the interaction effect between silicon and nitrogen in the content of chlorophyll, nitrate, ammonium and total nitrogen, dry matter production, number of tillers and number of panicles rice-plant cultivated in nutritional solution. A factorial design 5 x 2 trial installed in a completely randomized design was used being two silicon (0 and 50mg L-1 and five nitrogen (20; 50; l00; 200 and 400 mg L-1 concentrations. In the stadium of the flag leaf collar formation SPDA reading and the a and b chlorophyll contents, ammoniacal and total nitrogen determinations in plants were detemined. During the panicle complete maturity stadium, the number of tillers and panicles were evaluated and the aerial part and root dry matter contents and silicon

  4. 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

  5. Yes we can! Improving rice yield with diverse genetic resources

    Science.gov (United States)

    Rice breeding programs have been successful in using diverse germplasm for enhancement of pest resistance traits in rice, but traditionally have been less successful in using these materials for yield improvement. However, over the last decade Asian germplasm resources have proven to be fundamental ...

  6. Utilization of organic fertilizer to increase paddy growth and productivity using System of Rice Intensification (SRI method in saline soil

    Directory of Open Access Journals (Sweden)

    V . O . Subardja

    2016-01-01

    Full Text Available Soil salinity has negative effect on soil biodiversity as well as microbial activities. Hence, rice growth also effected by salinity. Application of organic fertilizer and adoption of System of Rice Intensification (SRI cultivation might improve the (biological soil properties and increase rice yield. The aim of this study was to evaluate the effect of two different rice cultivation methods namely conventional rice cultivation method and System of Rice Intensification (SRI rice cultivation method and two kinds organic fertilizer on improvement of soil biological properties and rice yield. In this study, a split plot experimental design was applied where rice cultivation method (conventional and SRI was the main plot and two kinds of organic fertilizer (market waste and rice straw was the sub plot. The treatments had four replicates. The results showed that SRI cultivation with market waste organic fertilizer could increase soil biological properties (population of microbe, fungi and soil respiration. The same treatment also increased rice growth and production. Combination of SRI and market waste organic fertilizer yielded the highest rice production (7.21 t/ha.

  7. 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

  8. 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.

  9. The Subtelomere of Oryza sativa Chromosome 3 Short Arm as a Hot Bed of New Gene Origination in Rice

    Science.gov (United States)

    Fan, Chuanzhu; Zhang, Yong; Yu, Yeisoo; Rounsley, Steve; Long, Manyuan; Wing, Rod A.

    2008-01-01

    Despite general observations of non-random genomic distribution of new genes, it is unclear whether or not new genes preferentially occur in certain genomic regions driven by related molecular mechanisms. Using 1.5 Mb of genomic sequences from short arms of chromosome 3 of Oryza glaberrima and O. punctata, we conducted a comparative genomic analysis with the reference O. sativa ssp. japonica genome. We identified a 60-kb segment located in the middle of the subtelomeric region of chromosome 3, which is unique to the species O. sativa. The region contained gene duplicates that occurred in Asian cultivated rice species that diverged from the ancestor of Asian and African cultivated rice one million years ago (MYA). For the 12 genes and one complete retrotransposon identified in this segment in O. sativa ssp. japonica, we searched for their parental genes. The high similarity between duplicated paralogs further supports the recent origination of these genes. We found that this segment was recently generated through multiple independent gene recombination and transposon insertion events. Among the 12 genes, we found that five had chimeric gene structures derived from multiple parental genes. Nine out of the 12 new genes seem to be functional, as suggested by Ka/Ks analysis and the presence of cDNA and/or MPSS data. Furthermore, for the eight transcribed genes, at least two genes could be classified as defense or stress response-related genes. Given these findings, and the fact that subtelomeres are associated with high rates of recombination and transcription, it is likely that subtelomeres may facilitate gene recombination and transposon insertions and serve as hot spots for new gene origination in rice genomes. PMID:19825586

  10. Agronomic evaluation of rain fed rice varieties in Seke - Banza area ...

    African Journals Online (AJOL)

    Six rain fed rice varieties from INERA (National Institute for Agronomic Study and Research) YANGAMBI center were cultivated at INERA GIMBI station. The objective was to get high yield rain fed rice varieties adapted to Seke-Banza area conditions in view to increase farmers' production and to reduce import of rice in the ...

  11. BIBLE A whole-air sampling as a window on Asian biogeochemistry

    Science.gov (United States)

    Elliott, Scott; Blake, Donald R.; Blake, Nicola J.; Dubey, Manvendra K.; Rowland, F. Sherwood; Sive, Barkley C.; Smith, Felisa A.

    2003-02-01

    Asian trace gas and aerosol emissions into carbon, nitrogen, and other elemental cycles will figure prominently in near term Earth system evolution. Atmospheric hydrocarbon measurements resolve numerous chemical species and can be used to investigate sourcing for key geocarriers. A recent aircraft study of biomass burning and lightning (BIBLE A) explored the East Asian atmosphere and was unique in centering on the Indonesian archipelago. Samples of volatile organics taken over/between the islands of Japan, Saipan, Java, and Borneo are here examined as a guide to whole-air-based studies of future Asian biogeochemistry. The midlatitude onshore/offshore pulse and tropical convection strongly influence concentration distributions. As species of increasing molecular weight are considered, rural, combustion, and industrial source regimes emerge. Methane-rich inputs such as waste treatment and rice cultivation are evidenced in the geostrophic outflow. The Indonesian atmosphere is rich in biomass burning markers and also those of vehicular activity. Complexity of air chemistry in the archipelago is a direct reflection of diverse topography, land use, and local economies in a rapidly developing nation. Conspicuous in its absence is the fingerprint for liquefied petroleum gas leakage, but it can be expected to appear as demand for clean fossil fuels rises along with per capita incomes. Combustion tracers indicate high nitrogen mobilization rates, linking regional terrestrial geocycles with open marine ecosystems. Sea to air fluxes are superimposed on continental and marine backgrounds for the methyl halides. However, ocean hot spots are not coordinated and suggest an intricate subsurface kinetics. Levels of long-lived anthropogenic halocarbons attest to the success of international environmental treaties while reactive chlorine containing species track industrial air masses. The dozens of hydrocarbons resolvable by gas chromatographic methods will enable monitoring of

  12. Genetics of wide compatible gene and variability studies in rice ...

    Indian Academy of Sciences (India)

    production and productivity on a sustainable basis. Exploita- tion of heterosis in rice has resulted in release of several hybrids for commercial cultivation in India. One of ... However, rice being the staple food of. Indians, improving its productivity has become a critically important issue (Subbaiah et al. 2011). Knowledge on ...

  13. Determinants of Yield Gap in Upland Rice Production in ...

    African Journals Online (AJOL)

    Respondents cultivated three improved rice varieties – ITA 150, WAB 189 and FARO 55 with average yield gaps of 1.52, 1.38 and 0.91 tons per hectare, respectively. This makes these rice varieties under-exploited as farmers operate at levels where they obtain an average of 49% of the potential yield. Factors which would ...

  14. Physical and Pasting Properties of 'Ofada' Rice ( Oryza sativa L ...

    African Journals Online (AJOL)

    In this study, grain physical and pasting properties of ofada rice cultivated in South-West Nigeria was evaluated using Standard Evaluation System (SES) for rice with the aim of providing basic information for brand development and utilization of ofada in the development of novel food products. Results showed that size and ...

  15. Survey of Rice Cropping Systems in Kampong Chhnang Province, Cambodia

    Directory of Open Access Journals (Sweden)

    Volker KLEINHENZ

    2013-03-01

    Full Text Available Although Cambodia might have achieved self-sufficiency and an exported surplus in rice production, its rice-based farming systems are widely associated with low productivity, low farmer income and rural poverty. The study is based on a questionnaire village survey in 14 communes containing 97 villages of Kampong Chhnang Province from March to June, 2011. It analyzes the prevailing rice-based cropping systems and evaluates options for their improvement. Differences in cropping systems depend on the distance from the Tonle Sap water bodies. At distances greater than 10 km, transplanted wet-season rice cropping system with low productivity of about 1.6 t/hm2 prevails. This deficiency can be primarily attributed to soils with high coarse sand fractions and low pH ( 4.0. Farmers predominantly cultivate dry-season recession rice between January and April. Seventy-nine percent of the area is sown directly and harvested by combines. Adoption ratio of commercial rice seeds is 59% and yields average 3.2 t/hm2. Introduction of the second dry-season rice between April and July may double annual yields in this rice cropping system. Besides upgrading other cultivation technologies, using seeds from commercial sources will improve yield and rice quality. Along with rice, farmers grow non-rice crops at different intensities ranging from single annual crops to intensive sequences at low yields.

  16. Determinants of Yield Gap in Lowland Rice Production in North ...

    African Journals Online (AJOL)

    Results indicated that rice farmers in the area cultivated four improved rice varieties WITA 4, FARO 15, FARO 35 and FARO 44 with average yield gaps of 1.48, 2.85, 3.03 and 3.20 tons per hectare respectively. This makes these rice varieties under-exploited as farmers operate at levels where they obtain an average of 49% ...

  17. Rice Nutrition

    Science.gov (United States)

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

  18. Dinitrogen fixation of rice-Klebsiella associations

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, I.D.; Fujii, T.; Sano, Y.; Komagata, K.; Yoneyama, T.; Iyama, S.; Hirota, Y.

    N/sub 2/ fixation by Klebsiella oxytoca strain NG13, isolated from the rhizosphere of a rice (Oryza sativa L.) plant, in association with Indica type rice strain, C5444 is reported. The C/sub 2/H/sub 2/-reduction assays, biomass measurements, N content determinations, and /sup 15/N isotopic dilution assays indicated that inoculation of C5444 with NG13 resulted in a 6% increase of total plant+soil N content, and a 19% /sup 15/N isotopic dilution of plant N after 120 days of cultivation. Our results demonstrated significant levels of N/sub 2/ fixation by K. oxytoca when associated with rice. By optimizing such rice plant-bacterial N/sub 2/ fixation capacity, the N uptake by rice could be enhanced.

  19. Response of aerobic rice to Piriformospora indica.

    Science.gov (United States)

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

    2014-03-01

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

  20. 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.

  1. Zinco, chumbo e cádmio em plantas de arroz (Oryza Sativa L. cultivadas em solo após adição de resíduo siderúrgico Zinc, lead and cadmium influence in rice plants (Oryza Sativa L. cultivated in soil with addition of siderurgical residue

    Directory of Open Access Journals (Sweden)

    André Fernão Martins de Andrade

    2008-10-01

    horizon of an Entisol, from Pinheiral municipality, State of Rio de Janeiro, and the rice (Oryza Sativa L. variety utilized was the "BRS Curinga". There were applied four dosages of residue (94; 281; 844 and 2531kg ha-1 plus the testimony, without residue. The amount of zinc, cadmium and lead was determined in the root and aerial part of the rice plants. The plants cultivated in the A horizon of the Entisol presented the biggest dry biomass production, the highest zinc accumulation, and the smallest cadmium level. The plants cultivated in the Oxisol B horizon had the smallest dry biomass production, lowest zinc accumulation, and the highest level of lead. As for the Oxisol A horizon, the rice plants showed a good dry biomass production. The zinc and lead concentrated, mainly, in the roots; and cadmium in the aerial part. Based on the characteristics of the studied soils, and the fitotoxicity by lead showed in the rice plants grown on the Oxisol B horizon, the application of the siderurgical residue, is not recommended, as a zinc source for the rice crop.

  2. Asian Ginseng

    Science.gov (United States)

    ... senticosus) is not related to true ginseng. In traditional Chinese medicine, Asian ginseng was used as a ... recommend against its use by infants, children, and women who are pregnant or breastfeeding. The most common ...

  3. Molecular evolution of shattering loci in U.S. weedy rice

    Science.gov (United States)

    Thurber, Carrie S.; Reagon, Michael; Gross, Briana L.; Olsen, Kenneth M.; Jia, Yulin; Caicedo, Ana L.

    2010-01-01

    Cultivated rice fields worldwide are plagued with weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Here, we investigate the shattering phenotype in a collection of U.S. weedy rice accessions, as well as wild and cultivated relatives. We find that all U.S. weedy rice groups shatter seeds easily, despite multiple origins, and in contrast to a decrease in shattering ability seen in cultivated groups. We assessed allelic identity and diversity at the major shattering locus, sh4, in weedy rice; we find that all cultivated and weedy rice, regardless of population, share similar haplotypes at sh4, and all contain a single derived mutation associated with decreased seed shattering. Our data constitute the strongest evidence to date of an evolution of weeds from domesticated backgrounds. The combination of a shared cultivar sh4 allele and a highly shattering phenotype, suggests that U.S. weedy rice have re-acquired the shattering trait after divergence from their progenitors through alternative genetic mechanisms. PMID:20584132

  4. The competitiveness of domestic rice production in East Africa: A domestic resource cost approach in Uganda

    Directory of Open Access Journals (Sweden)

    Masao Kikuchi

    2016-03-01

    Full Text Available The rapid increase of rice imports in sub-Saharan Africa under the unstable situation in the world rice market during the 2000s has made it an important policy target for the countries in the region to increase self-sufficiency in rice in order to enhance food security. Whether domestic rice production can be competitive with imported rice is a serious question in East African countries that lie close, just across the Arabian Sea, to major rice exporting countries in South Asia. This study investigates the international competitiveness of domestic rice production in Uganda in terms of the domestic resource cost ratio. The results show that rainfed rice cultivation, which accounts for 95% of domestic rice production, does not have a comparative advantage with respect to rice imported from Pakistan, the largest supplier of imported rice to Uganda. However, the degree of non-competitiveness is not serious, and a high possibility exists for Uganda’s rainfed rice cultivation to become internationally competitive by improving yield levels by applying more modern inputs and enhancing labour productivity. Irrigated rice cultivation, though very limited in area, is competitive even under the present input-output structure when the cost of irrigation infrastructure is treated as a sunk cost. If the cost of installing irrigation infrastructure and its operation and maintenance is taken into account, the types of irrigation development that are economically feasible are not large-scale irrigation projects, but are small- and microscale projects for lowland rice cultivation and rain-water harvesting for upland rice cultivation.

  5. Resilience and adaptability of rice terrace social-ecological systems: a case study of a local community's perception in Banaue, Philippines

    Directory of Open Access Journals (Sweden)

    Adam C. Castonguay

    2016-06-01

    Full Text Available The social-ecological systems of rice terraces across Southeast Asia are the result of centuries of long-term interactions between human communities and their surrounding ecosystems. Processes and structures in these systems have evolved to provide a diversity of ecosystem services and benefits to human societies. However, as Southeast Asian countries experience rapid economic growth and related land-use changes, the remaining extensive rice cultivation systems are increasingly under pressure. We investigated the long-term development of ecosystem services and the adaptive capacity of the social-ecological system of rice terrace landscapes using a case study of Banaue (Ifugao Province, Northern-Luzon, Philippines. A set of indicators was used to describe and assess changes in the social-ecological state of the study system. The resilience of the rice terraces and the human communities that maintain them was examined by comparing the current state of the system with results from the literature. Our findings indicate that, although the social-ecological system has not yet shifted to an alternative state, pressures are increasing and some cultural ecosystem services have already been lost.

  6. EFFECT OF CULTURAL CONDITIONS ON LOVASTATIN PRODUCTION BY ASPERGILLUS NIGER SAR I USING COMBINATION OF RICE BRAN AND BROWN RICE AS SUBSTRATE

    OpenAIRE

    Syarifah Abdul Rashid; Darah Ibrahim; I Nyoman Pugeg Aryantha

    2013-01-01

    A local fungal isolate Aspergillus niger SAR I produced high level of lovastatin activity when cultivated under solid substrate fermentation using a combination of rice bran and brown rice as substrate. The highest lovastatin production of 305.08±14.65 ug/g dry solid and 12±0.01 mg glucosamine/g substrate of fungal growth were achieved at the 10th day of cultivation after using all the optimized parameters (5 gram of unground rice bran and brown rice at the ratio of 1:1, water content of 70% ...

  7. (SRI) to Increase Rice Water Productivity

    African Journals Online (AJOL)

    , and 40x40 for T5 were ... cultivation by changing the management of plants, ..... Sustainability of. System of Rice Intensification: Benefits of SRI focusing on effects of intermittent irrigation on yield increase and water savings. In: Proceeding of ...

  8. AN ASSESSMENT OF LAND SUITABILITY FOR RICE ...

    African Journals Online (AJOL)

    Osondu

    Abstract. This study examined the suitability of the soil in Dobi, Gwagwalada Area Council, FCT, Nigeria for rice cultivation. Soil samples were collected from the plot using systematic sampling procedure, at two standard depths of 0-15cm (top soil) and 16-30cm (sub soil). Standard procedures as applied to tropical soils ...

  9. mediated transformation in two indica rice

    African Journals Online (AJOL)

    Agrobacterium tumefaciens strain EHA 105 carrying binary vector pCAMBIA 1301 was used for transformation in two economically important highly recalcitrant indica rice cultivars HKR-46 and HKR-126. High concentrations of acetosyringone in the agrobacterium culture and co-cultivation medium proved to be ...

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

    Science.gov (United States)

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

    2016-08-01

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

  11. De novo Transcriptome Assembly of Common Wild Rice (Oryza rufipogon Griff.) and Discovery of Drought-Response Genes in Root Tissue Based on Transcriptomic Data.

    Science.gov (United States)

    Tian, Xin-Jie; Long, Yan; Wang, Jiao; Zhang, Jing-Wen; Wang, Yan-Yan; Li, Wei-Min; Peng, Yu-Fa; Yuan, Qian-Hua; Pei, Xin-Wu

    2015-01-01

    The perennial O. rufipogon (common wild rice), which is considered to be the ancestor of Asian cultivated rice species, contains many useful genetic resources, including drought resistance genes. However, few studies have identified the drought resistance and tissue-specific genes in common wild rice. In this study, transcriptome sequencing libraries were constructed, including drought-treated roots (DR) and control leaves (CL) and roots (CR). Using Illumina sequencing technology, we generated 16.75 million bases of high-quality sequence data for common wild rice and conducted de novo assembly and annotation of genes without prior genome information. These reads were assembled into 119,332 unigenes with an average length of 715 bp. A total of 88,813 distinct sequences (74.42% of unigenes) significantly matched known genes in the NCBI NT database. Differentially expressed gene (DEG) analysis showed that 3617 genes were up-regulated and 4171 genes were down-regulated in the CR library compared with the CL library. Among the DEGs, 535 genes were expressed in roots but not in shoots. A similar comparison between the DR and CR libraries showed that 1393 genes were up-regulated and 315 genes were down-regulated in the DR library compared with the CR library. Finally, 37 genes that were specifically expressed in roots were screened after comparing the DEGs identified in the above-described analyses. This study provides a transcriptome sequence resource for common wild rice plants and establishes a digital gene expression profile of wild rice plants under drought conditions using the assembled transcriptome data as a reference. Several tissue-specific and drought-stress-related candidate genes were identified, representing a fully characterized transcriptome and providing a valuable resource for genetic and genomic studies in plants.

  12. Improvement of Salinity Stress Tolerance in Rice: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Thi My Linh Hoang

    2016-10-01

    Full Text Available Rice (Oryza sativa L. is an important staple crop that feeds more than one half of the world’s population and is the model system for monocotyledonous plants. However, rice is very sensitive to salinity and is the most salt sensitive cereal crop with a threshold of 3 dSm−1 for most cultivated varieties. Despite many attempts using different strategies to improve salinity tolerance in rice, the achievements so far are quite modest. This review aims to discuss challenges that hinder the improvement of salinity stress tolerance in rice as well as potential opportunities for enhancing salinity stress tolerance in this important crop.

  13. Pathways of Rice Diversification across Asia

    Directory of Open Access Journals (Sweden)

    Dorian Q Fuller

    2016-12-01

    Full Text Available The archaeology of rice has made important methodological advances over the past decade that have contributed new data on the domestication process, spread and ecology of cultivation. Growing evidence from spikelet bases indicates that non-shattering, domesticated forms evolved gradually in the Yangtze basin and that there were at least two distinct processes around the Middle Yangtze region pre-dating 6000 BC, and the in the Lower Yangtze region between 6000 and 4000 BC. Early rice cultivation in these areas was based on wet field ecologies, in contrast to rainfed rice that is indicated among the earliest systems in India. When rice first spread north it was not entirely suited to shorter temperate summer growth seasons, and we are able to infer from high levels of apparently green-harvested spikelets that genetic adaptations to temperate conditions evolved after 2000 BC. When rice first spread south, to mainland Southeast Asia, after 2500 BC, it was grown in rainfed, dry ecologies that were less labour- demanding and less-productive. More productive and intensive irrigated rice then redeveloped in Southeast Asia around 2000 years ago, supporting growing population densities and social complexity.

  14. Hydroponic cultivation of Oncidium baueri

    Directory of Open Access Journals (Sweden)

    Daniele Brandstetter Rodrigues

    2017-08-01

    Full Text Available In Brazil, orchid cultivation has been increasing steadily over the last few years and contributing significantly to the economy. It has been reported that several vegetable crops and ornamentals have been successfully grown by soilless cultivation. The orchid Oncidium baueri Lindl. is grown on pot substrates. Nevertheless, hydroponics is an excellent alternative, especially for the production of cut flowers and bare root plants. The objective of this study was to evaluate the development of Oncidium baueri on two soilless systems: (a pots containing Amafibra® coconut fiber, carbonized rice husk, and pine bark (1:1:1 irrigated with nutrient solution every 15 d; and (b a nutrient film technique (NFT hydroponic system irrigated with nutrient solution daily. Shoot height, pseudobulb diameter, and number of sprouts were evaluated monthly. The number of flowering plants, number of flowers, dry mass of shoots, and dry mass of roots were evaluated 11 months after onset of experiment. The pot cultivation system yielded more flowers and higher values for all vegetative parameters than the NFT hydroponic system.

  15. 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.

  16. Doubling genome size without polyploidization: Dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice

    Science.gov (United States)

    Piegu, Benoit; Guyot, Romain; Picault, Nathalie; Roulin, Anne; Saniyal, Abhijit; Kim, Hyeran; Collura, Kristi; Brar, Darshan S.; Jackson, Scott; Wing, Rod A.; Panaud, Olivier

    2006-01-01

    Retrotransposons are the main components of eukaryotic genomes, representing up to 80% of some large plant genomes. These mobile elements transpose via a “copy and paste” mechanism, thus increasing their copy number while active. Their accumulation is now accepted as the main factor of genome size increase in higher eukaryotes, besides polyploidy. However, the dynamics of this process are poorly understood. In this study, we show that Oryza australiensis, a wild relative of the Asian cultivated rice O. sativa, has undergone recent bursts of three LTR-retrotransposon families. This genome has accumulated more than 90,000 retrotransposon copies during the last three million years, leading to a rapid twofold increase of its size. In addition, phenetic analyses of these retrotransposons clearly confirm that the genomic bursts occurred posterior to the radiation of the species. This provides direct evidence of retrotransposon-mediated variation of genome size within a plant genus. PMID:16963705

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

    Science.gov (United States)

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

    2005-09-01

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

  18. Barnyard grass-induced rice allelopathy and momilactone B.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2011-07-01

    Here, we investigated chemical-mediated interaction between crop and weeds. Allelopathic activity of rice seedlings exhibited 5.3-6.3-fold increases when rice and barnyard grass seedlings were grown together, where there may be the competitive interference between rice and barnyard grass for nutrients. Barnyard grass is one of the most noxious weeds in rice cultivation. The momilactone B concentration in rice seedlings incubated with barnyard grass seedlings was 6.9-fold greater than that in rice seedlings incubated independently. Low nutrient growth conditions also increased allelopathic activity and momilactone B concentrations in rice seedlings. However, the increases in the low nutrient-induced allelopathic activity and momilactone B concentration were much lower than those in barnyard grass-induced allelopathic activity and momilactone B concentration. Root exudates of barnyard grass seedlings increased allelopathic activity and momilactone B concentration in rice seedlings at concentrations greater than 30 mg/L of the root exudates, and increasing the exudate concentration increased the activity and momilactone B concentration. Therefore, barnyard grass-induced allelopathic activity of rice seedlings may be caused not only by nutrient competition between two species, but also by components in barnyard grass root exudates. As momilactone B shows strong allelopathic activities, barnyard grass-induced allelopathic activity of rice may be due to the increased concentration of momilactone B in rice seedlings. The present research suggests that rice may respond to the presence of neighboring barnyard grass by sensing the components in barnyard grass root exudates and increasing allelopathic activity by production of elevated concentration of momilactone B. Thus, rice allelopathy may be one of the inducible defense mechanisms by chemical-mediated plant interaction between rice and barnyard grass, and the induced-allelopathy may provide a competitive advantage for

  19. Cultivation of Schizophyllum commune mushroom on different wood substrates

    Directory of Open Access Journals (Sweden)

    P.N. Dasanayaka

    2017-07-01

    Full Text Available Schizophyllum commune is an edible mushroom grown on wood under natural conditions. Present study focused on cultivation of S.commune on different wood substrates since it is not commercially cultivated. A pure culture of S. commune was obtained by growing a tissue of the mushroom on Potato Dextrose Agar (PDA medium. Spawns were produced by growing the mycelium on paddy grains. Mushroom was cultivated on sawdust of seven different wood substrates. The maximum yield was observed in sawdust of jackfruit (Artocarpusheterophyllus followed by sawdust of rambutan (Nepheliumlappaceum and country almond (Terminaliacatappa. A significant difference was not observed when mango (Mangiferaindica elephant apple (Dilleniaindica, tulip wood tree (Harpulliaarborea and thungfaa (Alstoniamacrophylla sawdust used as substrate. The lowest yield was observed in thungfaa (Alstoniamacrophylla sawdust. Effect of some additives on the yield was studied and significant difference in yield was observed when rice bran and used-tea leaves used as additives. Effect of rice bran on yield was studied using different ratios of sawdust to rice bran and the highest was observed in 2:1 ratio of sawdust to rice bran. The best incubating temperature for mycelial growth on the substrate was 350C. The composition of the mushroom on a dry weight basis was; 71.4% moisture, 23.35% crude protein and 6% ash. Tested wood species are promising substrates for cultivation of S.communeas cottage industry.

  20. Silicon-mediated resistance in a susceptible rice variety to the rice leaf folder, Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Han, Yongqiang; Lei, Wenbin; Wen, Lizhang; Hou, Maolin

    2015-01-01

    The rice leaf folder, Cnaphalocrocis medinalis (Guenée), is one of the most destructive rice pests in Asian countries. Rice varieties resistant to the rice leaf folder are generally characterized by high silicon content. In this study, silicon amendment, at 0.16 and 0.32 g Si/kg soil, enhanced resistance of a susceptible rice variety to the rice leaf folder. Silicon addition to rice plants at both the low and high rates significantly extended larval development and reduced larval survival rate and pupation rate in the rice leaf folder. When applied at the high rate, silicon amendment reduced third-instars' weight gain and pupal weight. Altogether, intrinsic rate of increase, finite rate of increase and net reproduction rate of the rice leaf folder population were all reduced at both the low and high silicon addition rates. Although the third instars consumed more in silicon-amended treatments, C:N ratio in rice leaves was significantly increased and food conversion efficiencies were reduced due to increased silicon concentration in rice leaves. Our results indicate that reduced food quality and food conversion efficiencies resulted from silicon addition account for the enhanced resistance in the susceptible rice variety to the rice leaf folder.

  1. Silicon-mediated resistance in a susceptible rice variety to the rice leaf folder, Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae.

    Directory of Open Access Journals (Sweden)

    Yongqiang Han

    Full Text Available The rice leaf folder, Cnaphalocrocis medinalis (Guenée, is one of the most destructive rice pests in Asian countries. Rice varieties resistant to the rice leaf folder are generally characterized by high silicon content. In this study, silicon amendment, at 0.16 and 0.32 g Si/kg soil, enhanced resistance of a susceptible rice variety to the rice leaf folder. Silicon addition to rice plants at both the low and high rates significantly extended larval development and reduced larval survival rate and pupation rate in the rice leaf folder. When applied at the high rate, silicon amendment reduced third-instars' weight gain and pupal weight. Altogether, intrinsic rate of increase, finite rate of increase and net reproduction rate of the rice leaf folder population were all reduced at both the low and high silicon addition rates. Although the third instars consumed more in silicon-amended treatments, C:N ratio in rice leaves was significantly increased and food conversion efficiencies were reduced due to increased silicon concentration in rice leaves. Our results indicate that reduced food quality and food conversion efficiencies resulted from silicon addition account for the enhanced resistance in the susceptible rice variety to the rice leaf folder.

  2. Modern elite rice varieties of the 'Green Revolution' have retained a large introgression from wild rice around the Pi33 rice blast resistance locus.

    Science.gov (United States)

    Ballini, Elsa; Berruyer, Romain; Morel, Jean-Benoît; Lebrun, Marc-Henri; Nottéghem, Jean-Loup; Tharreau, Didier

    2007-01-01

    During the breeding process of cultivated crops, resistance genes to pests and diseases are commonly introgressed from wild species. The size of these introgressions is predicted by theoretical models but has rarely been measured in cultivated varieties. By combining resistance tests with isogenic strains, genotyping and sequencing of different rice accessions, it was shown that, in the elite rice variety IR64, the resistance conferring allele of the rice blast resistance gene Pi33 was introgressed from the wild rice Oryza rufipogon (accession IRGC101508). Further characterization of this introgression revealed a large introgression at this locus in IR64 and the related variety IR36. The introgressed fragment represents approximately half of the short arm of rice chromosome 8. This is the first report of a large introgression in a cultivated variety of rice. Such a large introgression is likely to have been maintained during backcrossing only if a selection pressure was exerted on this genomic region. The possible traits that were selected are discussed.

  3. Aroma chemistry of African Oryza glaberrima and Oryza sativa rice and their interspecific hybrids

    NARCIS (Netherlands)

    Cho, S.; Nuijten, H.A.C.P.; Shewfelt, R.L.; Kays, S.J.

    2014-01-01

    BackgroundTo increase rice production in Africa, considerable research has focused on creating interspecific hybrids between African (Oryza glaberrima Steud.) and Asian (O. sativa L.) rice in an attempt to obtain the positive attributes of each in new cultivars. Since flavor is a key criterion in

  4. Higher yields and lower methane emissions with new rice cultivars.

    Science.gov (United States)

    Jiang, Yu; van Groenigen, Kees Jan; Huang, Shan; Hungate, Bruce A; van Kessel, Chris; Hu, Shuijin; Zhang, Jun; Wu, Lianhai; Yan, Xiaojun; Wang, Lili; Chen, Jin; Hang, Xiaoning; Zhang, Yi; Horwath, William R; Ye, Rongzhong; Linquist, Bruce A; Song, Zhenwei; Zheng, Chengyan; Deng, Aixing; Zhang, Weijian

    2017-11-01

    Breeding high-yielding rice cultivars through increasing biomass is a key strategy to meet rising global food demands. Yet, increasing rice growth can stimulate methane (CH4 ) emissions, exacerbating global climate change, as rice cultivation is a major source of this powerful greenhouse gas. Here, we show in a series of experiments that high-yielding rice cultivars actually reduce CH4 emissions from typical paddy soils. Averaged across 33 rice cultivars, a biomass increase of 10% resulted in a 10.3% decrease in CH4 emissions in a soil with a high carbon (C) content. Compared to a low-yielding cultivar, a high-yielding cultivar significantly increased root porosity and the abundance of methane-consuming microorganisms, suggesting that the larger and more porous root systems of high-yielding cultivars facilitated CH4 oxidation by promoting O2 transport to soils. Our results were further supported by a meta-analysis, showing that high-yielding rice cultivars strongly decrease CH4 emissions from paddy soils with high organic C contents. Based on our results, increasing rice biomass by 10% could reduce annual CH4 emissions from Chinese rice agriculture by 7.1%. Our findings suggest that modern rice breeding strategies for high-yielding cultivars can substantially mitigate paddy CH4 emission in China and other rice growing regions. © 2017 John Wiley & Sons Ltd.

  5. Potential for phytoextraction of copper, lead, and zinc by rice (Oryza sativa L.), soybean (Glycine max [L.] Merr.), and maize (Zea mays L.).

    Science.gov (United States)

    Murakami, Masaharu; Ae, Noriharu

    2009-03-15

    Phytoextraction by hyperaccumulators has been proposed for decreasing toxic-metal concentrations of contaminated soils. However, hyperaccumulators have several shortcomings to introduce these species into Asian Monsoon's agricultural fields contaminated with low to moderate toxic-metals. To evaluate the phytoextraction potential, maize (Gold Dent), soybean (Enrei and Suzuyutaka), and rice (Nipponbare and Milyang 23) were pot-grown under aerobic soil conditions for 60d on the Andosol or Fluvisol with low to moderate copper (Cu), lead (Pb), and zinc (Zn) contamination. After 2 months cultivation, the Gold Dent maize and Milyang 23 rice shoots took up 20.2-29.5% and 18.5-20.2% of the 0.1molL(-1) HCl-extractable Cu, 10.0-37.3% and 8.5-34.3% of the DTPA-extractable Cu, and 2.4-6.5% and 2.1-5.9% of the total Cu, respectively, in the two soils. Suzuyutaka soybean shoot took up 23.0-29.4% of the 0.1molL(-1) HCl-extractable Zn, 35.1-52.6% of the DTPA-extractable Zn, and 3.8-5.3% of the total Zn in the two soils. Therefore, there is a great potential for Cu phytoextraction by the Gold Dent maize and the Milyang 23 rice and for Zn phytoextraction by the Suzuyutaka soybean from paddy soils with low to moderate contamination under aerobic soil conditions.

  6. Classification of cultivated plants.

    NARCIS (Netherlands)

    Brandenburg, W.A.

    1986-01-01

    Agricultural practice demands principles for classification, starting from the basal entity in cultivated plants: the cultivar. In establishing biosystematic relationships between wild, weedy and cultivated plants, the species concept needs re-examination. Combining of botanic classification, based

  7. Balanço de nutrientes e da fitomassa em um Argissolo Amarelo sob floresta tropical amazônica após a queima e cultivo com arroz Nutrient and phytomass dynamics in a yellow Argissol under Amazonian tropical forest after burning and rice cultivation

    Directory of Open Access Journals (Sweden)

    F. A. R. Sampaio

    2003-12-01

    burned areas with cultivation of rice (cultivated. Furthermore, these areas were compared with an area of primary vegetation (forest used as reference. Burning consumed 36.3% of the initial biomass and produced 5.5 Mg ha-1 of ashes with significant amounts of nutrients, mainly Ca, Mg, and K. To clear areas by means of burning turned out to be a practice of low efficiency, because only a small percentage of the original biomass was converted into ashes and the greatest part remained in the form of residues. Even with the restitution of nutrients such as Ca, Mg, K by rain, there was a considerable removal of N, P, K, Ca, Mg, and S, on the one hand by direct action of the fire, on the other through the carrying off of the ashes by the wind, and/or the removal by the crop. Results indicated that nutrient loss in the burned uncultivated area was greater than in the burned cultivated one, demonstrating the importance of soil covering to keep the elements in the system. At the end of the culture cycle, the residual effect of the ashes was still noticeable in the system, clearly expressed by the P, K, Ca, and Mg values which were higher than those measured in the control area (forest.

  8. Gene, protein and network of male sterility in rice

    OpenAIRE

    Wang eKun; Peng eXiaojue; Ji eYanxiao; Pingfang eYang; Zhu eYingguo; Shaoqing eLi

    2013-01-01

    Rice is one of the most important model crop plants whose heterosis has been well exploited in commercial hybrid seed production via a variety of types of male sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes an...

  9. Gene, protein, and network of male sterility in rice

    OpenAIRE

    Wang, Kun; Peng, Xiaojue; Ji, Yanxiao; Yang, Pingfang; Zhu, Yingguo; Li, Shaoqing

    2013-01-01

    Rice is one of the most important model crop plants whose heterosis has been well-exploited in commercial hybrid seed production via a variety of types of male-sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and prot...

  10. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    OpenAIRE

    Zhang, Yu-Zhu; Liu, Yang; Zeng, Xiang; Chen, Kai-Lin; Ze-hui HUANG; Hong-ke XIE

    2011-01-01

    The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-22

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

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

    Science.gov (United States)

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

    2015-07-30

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

  13. 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...... explanations for patterns of variation in domesticated rice varieties. If selective sweeps are indeed the explanation for the observed nucleotide data of domesticated rice, it suggests that strong selection can leave its imprint on genome-wide polymorphism patterns, contrary to expectations that selection...

  14. 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.

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

    Science.gov (United States)

    Gross, Briana L.; Zhao, Zhijun

    2014-01-01

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

  16. Letter to the editor: Rice: location is vital in crop management

    NARCIS (Netherlands)

    Hengsdijk, H.; Bindraban, P.S.

    2004-01-01

    Your News Feature about rice cultivation, "Feast or famine?" (Nature 428, 360–361; 2004), is a classic example of how the debate on a potentially interesting technique can be blurred by its opponents and proponents. In this case, proponents of the System of Rice Intensification (SRI) are reported to

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    2010-01-01

    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. PMID:20550656

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

    Science.gov (United States)

    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

  20. Human exposure to mercury in a compact fluorescent lamp manufacturing area: By food (rice and fish) consumption and occupational exposure.

    Science.gov (United States)

    Liang, Peng; Feng, Xinbin; Zhang, Chan; Zhang, Jin; Cao, Yucheng; You, Qiongzhi; Leung, Anna Oi Wah; Wong, Ming-Hung; Wu, Sheng-Chun

    2015-03-01

    To investigate human Hg exposure by food consumption and occupation exposure in a compact fluorescent lamp (CFL) manufacturing area, human hair and rice samples were collected from Gaohong town, Zhejiang Province, China. The mean values of total mercury (THg) and methylmercury (MeHg) concentrations in local cultivated rice samples were significantly higher than in commercial rice samples which indicated that CFL manufacturing activities resulted in Hg accumulation in local rice samples. For all of the study participants, significantly higher THg concentrations in human hair were observed in CFL workers compared with other residents. In comparison, MeHg concentrations in human hair of residents whose diet consisted of local cultivated rice were significantly higher than those who consumed commercial rice. These results demonstrated that CFL manufacturing activities resulted in THg accumulation in the hair of CFL workers. However, MeHg in hair were mainly affected by the sources of rice of the residents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Improvement of the Value of Green Manure via Mixed Hairy Vetch and Barley Cultivation in Temperate Paddy Soil

    NARCIS (Netherlands)

    Hwang, Hyun Young; Kim, Gil Won; Lee, Yong Bok; Kim, Pil Joo; Kim, Sang Yoon

    2015-01-01

    Legume hairy vetch and non-legume barley mixtures are broadly cultivated to improve the value of cover crops in mono-rice paddies. Nevertheless, the effects of mixing conditions of the two cover crops on biomass and nutrient productivities and on the yield characteristics of subsequent rice crops

  2. Caracterização da fração protéica da cianobactéria Aphanothece Microscopica Nägeli cultivada no efluente da parboilização do arroz Protein characterisation of the Aphanothece Microscopica Nägeli cyanobacterium cultivated in parboiled rice effluent

    Directory of Open Access Journals (Sweden)

    Eduardo Jacob-Lopes

    2006-06-01

    Full Text Available O objetivo do presente trabalho foi avaliar a fração protéica da cianobactéria Aphanothece microscopica Nägeli cultivada no efluente da parboilização do arroz quando submetida a diferentes condições de secagem. A produção da biomassa foi realizada a partir da água residuária do processo de parboilização do arroz em bioreatores de coluna de bolhas. A biomassa foi separada do efluente por centrifugação e desidratada em secador descontínuo de bandejas nas condições de 40, 50 e 60ºC e espessuras de bandejas de 5 e 7 mm. O comportamento eletroforético das proteínas da biomassa foi analisado por eletroforese em gel de poliacrilamamida na presença de dodecil sulfato de sódio (SDS-PAGE e apresentou bandas com peso molecular de 15 kDa a 62,5 kDa. O perfil aminoacídico mostrou teores superiores aos recomendados pelo padrão FAO, com exceção dos aminoácidos lisina e dos sulfurados (MET+CYS. A caracterização funcional, expressa em termos de solubilidade e capacidade emulsificante, demonstrou a influência da condição de secagem na funcionalidade protéica da biomassa.The objective of the present work was to evaluate the protein fraction of Aphanothece microscopica Nägeli cyanobacteria cultivated in the parboiled rice effluent, submitted to different drying conditions. The production of the biomass was done by using wastewater from the process of rice parboiling in a bubble column bioreactor. The biomass was separated from the effluent by centrifugation and dehydrated in a tray dryer at 40, 50 and 60ºC and thicknesses of 5 and 7 mm. The eletroforetic profile of proteins of the biomass was analysed by SDS-PAGE and presented bands with molecular weight between 62.5-15kDa. The amino acid profile was higher than the concentrations recommended by standard FAO, with the exception of the amino acids (LYS and the sulphurated (MET+CYS. The functional properties characterisation in terms of protein solubility and emulsification

  3. Eficiência de extratores de fósforo para um solo adubado com fosfatos e cultivado com arroz The efficiency of phosphorus extractants for a soil treated with phosphatic fertilizers and cultivated to rice

    Directory of Open Access Journals (Sweden)

    J.S.DE Holanda

    1995-12-01

    Full Text Available Visando comparar a eficiência de extratores químicos e isotópico na avaliação da disponibilidade de fósforo no solo, foi conduzido um experimento em casa de vegetação com Latossolo Vermelho-Amarelo. Foram realizados dois cultivos anteriores, com aplicação de fosfatos somente no primeiro. Os fosfatos usados foram: superfosfato simples, termofosfato Yoorin, Fosmag, fosfatos de Araxá e de Gafsa, nas doses de 50 e 150 mg.kg-1 terra. Neste experimento, terceiro cultivo, foram avaliados os extratores: Mehlich 1, Bray-1, resina e valor "E". As maiores correlações entre P-extraível do solo com produção de matéria seca e absorção de P pelo arroz foram apresentadas pelos extratores Bray-1 (r = 0,92 e resina (r = 0,91. O fósforo determinado pelo extrator Mehlich-1 somente apresentou alta correlação com os parâmetros da ¡danta (r = 0,96 quando da exclusão dos tratamentos com fosfato de Araxá. Os resultados de fósforo extraído pelo Bray-1 e resina foram altamente correlacionados entre si (r = 0,98.In order to assess the efficiency of several extracting procedures for soil phosphorus a pot experiment was carried out using a Red Yellow Latosol. Previously two successive croppings had been made, P fertilizers being applied only in the first one. The following products were used at the rates of 50 and 150 mg.kg-1 soil: Yoorin (thermo-phosphate, "Fosmag", Araxa and Gafsa rock phosphates. Mehlich-1, Bray-1, anion exchange resin, and isotopic dilution ("E" value methods were used as extracting procedures of available soil-P. The closest correlations between soil - P and either dry matter yield or phosphorus taken up by the rice plant were found with Bray-1 (r = 0.92 and resin (r = 0.91. Phosphorus determined by Mehlich-1 extracting solution showed high correlation with plant parameters (r = 0.96 only when the Araxa rock phosphate treatments were excluded from the calculation. High correlations (r = 0.98 were found between the values

  4. Assessing rice crop damage and restoration using remote sensing in tsunami-affected areas, Japan

    Science.gov (United States)

    Chen, Chi-Farn; Son, Nguyen-Thanh; Chen, Cheng-Ru; Cho, Kohei; Hsiao, Ya-Yun; Chiang, Shou-Hao; Chang, Ly-Yu

    2015-01-01

    The tsunami that occurred on March 11, 2011, in Japan caused widespread devastation of infrastructure and rice cultivation areas. This study assessed the rice growing areas damaged due to this event and the restoration progress using moderate resolution imaging spectroradiometer data. The data were processed for 2010 to 2013, comprising four main steps: (1) data preprocessing to construct the smooth time-series enhanced vegetation index 2 data, (2) rice crop mapping using the dynamic time warping algorithm, (3) accuracy assessment, and (4) change analysis of rice cultivation areas. The mapping results validated using the ground reference data indicated overall accuracies and kappa coefficients generally >84.3% and 0.69, respectively. The results, also verified with the government's rice area statistics, reaffirmed a close correlation between these two datasets (R2>0.77). When examining changes of rice cultivation between 2010 and 2013, the rice area damaged by the tsunami during 2010 to 2011 was ˜17,550 ha. The rice area restored after one year (2012) was ˜6663 ha, but this regressed slightly in 2013 (5656 ha). Such information could be used by officials to better understand the tsunami-damaged rice area and the restoration progress for crop management in the study region.

  5. Young Asian Dutch constructing Asianness: Understanding the role of Asian popular culture

    OpenAIRE

    Kartosen, R.A.

    2016-01-01

    This doctoral thesis is about young Asian Dutch, panethnic Asian identities and identifications, and Asian/Asian Dutch popular culture. It addresses several pressing questions, including: why do young Asian Dutch, who were born and/or raised in the Netherlands, identify as Asian and construct Asian identities? What is the content or meaning of these Asian identities and identifications young Asian Dutch imagine? And how do these relate to young Asian Dutch’ Dutch and homeland identities and i...

  6. 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

  7. 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.

  8. Duplication and Loss of Function of Genes Encoding RNA Polymerase III Subunit C4 Causes Hybrid Incompatibility in Rice

    Directory of Open Access Journals (Sweden)

    Giao Ngoc Nguyen

    2017-08-01

    Full Text Available Reproductive barriers are commonly observed in both animals and plants, in which they maintain species integrity and contribute to speciation. This report shows that a combination of loss-of-function alleles at two duplicated loci, DUPLICATED GAMETOPHYTIC STERILITY 1 (DGS1 on chromosome 4 and DGS2 on chromosome 7, causes pollen sterility in hybrid progeny derived from an interspecific cross between cultivated rice, Oryza sativa, and an Asian annual wild rice, O. nivara. Male gametes carrying the DGS1 allele from O. nivara (DGS1-nivaras and the DGS2 allele from O. sativa (DGS2-T65s were sterile, but female gametes carrying the same genotype were fertile. We isolated the causal gene, which encodes a protein homologous to DNA-dependent RNA polymerase (RNAP III subunit C4 (RPC4. RPC4 facilitates the transcription of 5S rRNAs and tRNAs. The loss-of-function alleles at DGS1-nivaras and DGS2-T65s were caused by weak or nonexpression of RPC4 and an absence of RPC4, respectively. Phylogenetic analysis demonstrated that gene duplication of RPC4 at DGS1 and DGS2 was a recent event that occurred after divergence of the ancestral population of Oryza from other Poaceae or during diversification of AA-genome species.

  9. Aerobic rice: crop performance and water use efficiency

    Directory of Open Access Journals (Sweden)

    Chiara Grassi

    2011-11-01

    Full Text Available Rice (Oryza sativa production largely depends on traditional flooded rice systems whose sustainability is threatened by a progressive decrease in water availability and a constant increase in rice demand due to strong demographic boom in world population. A newly developed water-saving rice system is aerobic rice in which rice grows in nonflooded and unsaturated soil. From 2001, at the International Rice Research Institute in the Philippines, this system has been monitored to identify potentially promising varieties of rice able to grow as an irrigated upland crop and quantify yield potential and water use efficiency. This study reports on the results of cultivating the upland rice variety Apo under different water conditions in 2004-2005 at the IRRI farm in both the dry and wet seasons. The water treatments considered were: aerobic and flooded conditions, alternated flooded and aerobic conditions and aerobic after fallow. Yield and water productivity were compared between aerobic and flooded treatment in both seasons, with the objective of analysing the differences between water treatments. In the experiment the effect of different nitrogen (N application is also considered. The results indicate that the aerobic rice yield was lower than rice production under flood treatment, confirming that observed over past years. Nevertheless, when the aerobic condition is alternated with the anaerobic condition, or a fallow period, the production under aerobic treatment provides good yields (respectively 4.2 and 4.4 ha-1. The fallow period was introduced to observe the response of rice grown under this management. Water productivity was higher in aerobic fields, especially after fallow (0.88 g kg-1. The nitrogen application induced an increase in yield and water productivity, partially compensating for the lack of water in aerobic fields.

  10. Red Yeast Rice

    Directory of Open Access Journals (Sweden)

    Thu Nguyen

    2017-03-01

    Full Text Available Red yeast rice (RYR, produced by the fermentation of the Monascus purpureus mold, has been used for a long time in Asian cuisine and traditional medicine. It consists of multiple bioactive substances, including monacolins, which potentially can be used as a nutraceutical. Monacolin K, which is chemically identical to lovastatin, has been recognized as responsible for the cholesterolreducing effect of this compound. While the European Food Safety Authority maintains that the use of monacolin K from RYR preparations of at least 10 mg can produce a normal blood cholesterol level, the United States Food and Drug Administration considers monacolin K, due to its similarity with lovastatin, an unapproved drug, and therefore marketing of products that label the monacolin content is prohibited. This mini-review summarizes the benefit of RYR in hyperlipidemia, maintains RYR use as a food, and addresses the importance of regulation regarding RYR and the need for clinical data and clear label information for consumers with reference to a toxin-free, nonaugmented, standardized amount of monacolins.

  11. Red Yeast Rice.

    Science.gov (United States)

    Nguyen, Thu; Karl, Mitchell; Santini, Antonello

    2017-03-01

    Red yeast rice (RYR), produced by the fermentation of the Monascus purpureus mold, has been used for a long time in Asian cuisine and traditional medicine. It consists of multiple bioactive substances, including monacolins, which potentially can be used as a nutraceutical. Monacolin K, which is chemically identical to lovastatin, has been recognized as responsible for the cholesterolreducing effect of this compound. While the European Food Safety Authority maintains that the use of monacolin K from RYR preparations of at least 10 mg can produce a normal blood cholesterol level, the United States Food and Drug Administration considers monacolin K, due to its similarity with lovastatin, an unapproved drug, and therefore marketing of products that label the monacolin content is prohibited. This mini-review summarizes the benefit of RYR in hyperlipidemia, maintains RYR use as a food, and addresses the importance of regulation regarding RYR and the need for clinical data and clear label information for consumers with reference to a toxin-free, nonaugmented, standardized amount of monacolins.

  12. 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.

  13. Young Asian Dutch constructing Asianness: Understanding the role of Asian popular culture

    NARCIS (Netherlands)

    Kartosen, R.A.

    2016-01-01

    This doctoral thesis is about young Asian Dutch, panethnic Asian identities and identifications, and Asian/Asian Dutch popular culture. It addresses several pressing questions, including: why do young Asian Dutch, who were born and/or raised in the Netherlands, identify as Asian and construct Asian

  14. Effect of acetic acid on rice seeds coated with rice husk ash

    Directory of Open Access Journals (Sweden)

    Lizandro Ciciliano Tavares

    2013-06-01

    Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

  15. Effects of soaking, germination and fermentation on phytic acid, total and in vitro soluble zinc in brown rice

    NARCIS (Netherlands)

    Liang, J.; Han, B.Z.; Nout, M.J.R.; Hamer, R.J.

    2008-01-01

    Rice is an important staple food in Asian countries. In rural areas it is also a major source of micronutrients. Unfortunately, the bioavailability of minerals, e.g. zinc from rice, is low because it is present as an insoluble complex with food components such as phytic acid. We investigated the

  16. What are Asian-American youth consuming? A systematic literature review.

    Science.gov (United States)

    Diep, Cassandra S; Foster, Margaret J; McKyer, E Lisako J; Goodson, Patricia; Guidry, Jeffrey J; Liew, Jeffrey

    2015-04-01

    Numerous studies have explored dietary practices among children, but there are limited studies on children of Asian background in the US. This review had three aims: (a) review literature regarding Asian-American youth's dietary behaviors, (b) critically evaluate the methodological quality of such research, and (c) provide recommendations for future nutrition-related research on Asian-American youth. The authors conducted a systematic literature review through MEDLINE (EBSCO), CINAHL Plus with Full Text (EBSCO), and Embase (Ovid); extracted descriptive data; and evaluated methodological quality. Thirteen articles were included. Major findings included: (a) frequent consumption of milk, fruit, meat, unenriched white rice, vegetables, and high-fat and high-sugar items among Asian-American children and (b) acculturation's influences on diet, resulting in Asian-American youth consuming diets characterized by both Asian and American foods. Findings from this review may inform education and promotion programs and services for Asian Americans in the US.

  17. Evaluation of gravel concentration and soil strength in upland rice ...

    African Journals Online (AJOL)

    Evaluation of gravel concentration and soil strength in upland rice cultivation in Abeokuta, Southwestern Nigeria. FK Salako, O Osiname. Abstract. No Abstract. Nigerian Journal of Soil Sciences Vol. 16 (1) 2006: pp. 67-76. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  18. Socio-Economic Determinants Of Upland Rice Production Among ...

    African Journals Online (AJOL)

    It is recommended that Research institutes should develop and transfer sustainable technologies on rice cultivation, processing, packaging and marketing using other method of information dissemination other than print to the farmers. There should be provision of irrigation facilities for the farmers so that they can be able to ...

  19. Evaluation of spectral reflectance of seven Iranian rice varieties canopies

    NARCIS (Netherlands)

    Darvishsefat, A.A.; Abbasi, M.; Schaepman, M.E.

    2011-01-01

    Rice cultivated areas and yield information is indispensable for sustainable management and economic policy making for this strategic food crop. Introduction of high spectral and special resolution satellite data has enabled production of such information in a timely and accurate manner. Knowledge

  20. Characterization of wide cross derivatives in rice Oryza sativa L ...

    African Journals Online (AJOL)

    hope&shola

    2010-10-04

    Oct 4, 2010 ... Interspecific crosses provide a bridge by which the gene pool of rice can be increased. Introduction of alien genes requires hybridization followed by meiotic pairing and recombination between the chromosomes of cultivated and wild species. Attempts have been made to visualize the genomic constitution ...

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Euan; Kempson, Ivan; Juhasz, Albert L.; Weber, John; Skinner, William M.; Gräfe, Markus; (U. South Australia); (Sydney)

    2009-09-14

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

  3. Spirulina cultivation in China

    Science.gov (United States)

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

    1998-03-01

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

  4. Seed treatment, soil compaction and nitrogen management affect upland rice

    Directory of Open Access Journals (Sweden)

    Veneraldo Pinheiro

    2016-03-01

    Full Text Available Water availability for cultivation of irrigated rice (Oryza sativa L. is decreasing worldwide. Therefore, new technologies are needed to grow rice under aerobic conditions, in order to produce rice grains without yield losses and with lower water consumption. This study aimed at determining the best combination of management options for producing upland rice. A randomized blocks design, in a factorial scheme, was used. The treatments consisted of a combination of five rice cultivars (BRS Caçula, BRS Serra Dourada, BRS Primavera, BRS Sertaneja and BRS Esmeralda with two compaction pressures in the seed furrow (25 kPa or 126 kPa, two types of seed treatment (with or without pesticide and two types of N management (all at sowing or all at topdressing. Applying N at sowing instead of at topdressing produced higher grain yield in the no-tillage system (NTS. Under this system, upland rice genotypes show higher grain yield with higher compaction pressure. Seed treatment with pesticide provided greater grain yield for the BRS Sertaneja, in NTS, and for all genotypes in the conventional tillage system (CTS. BRS Esmeralda, in NTS, and BRS Esmeralda and BRS Primavera, in CTS, were the most productive genotypes. Moreover, in NTS, the application of N at sowing and the compaction pressure on the seed furrow are important for increasing upland rice grain yield. In CTS, seed treatment is important to improve upland rice grain yield.

  5. Rice bran: a novel functional ingredient.

    Science.gov (United States)

    Sharif, Mian Kamran; Butt, Masood Sadiq; Anjum, Faqir Muhammad; Khan, Saima Hafiz

    2014-01-01

    Rice (Oryza sativa) is the most important staple food for a large part of the world's human population, especially in East and South Asia, the Middle East, Latin America, and the West Indies. It provides more than one fifth of the calories consumed worldwide by the human. It is the second leading cereal crop and staple food of half of the world's population. It is grown in at least 114 countries with global production of 645 million tons; share of Asian farmers is about 90% of the total produce. Rice bran, brown outer layer of rice kernel, is mainly composed of pericarp, aleurone, subaleurone layer, and germ. It contains appreciable quantities of nutrients like protein, fat, and dietary fiber. Furthermore, it contains substantial amount of minerals like K, Ca, Mg, and Fe. Presence of antioxidants like tocopherols, tocotrienols, and γ-oryzanol also brighten prospects of rice bran utilization for humans as functional ingredient to mitigate the life-threatening disorders. Moreover, in the developing countries, budding dilemma of food crisis, arising due to lower crop yields and escalating population, needs to utilize each pent of available resources. To provide enough food to all people, there is the holistic approach of using the by-products generated during food processing and preparations. Rice is being processed in well-established industry, but the major apprehension is the utilization of its by-products; rice bran (5-8%) and polishing (2-3%) that are going as waste. Rice processing or milling produces several streams of materials including milled rice, bran, and husk. In developing countries, rice bran is considered as a by-product of the milling process and commonly used in animal feed or discarded as a waste. The potential of producing rice bran at the global level is 29.3 million tons annually, whereas the share of Pakistan is worked out to be 0.5 million tons. In present paper, attempt has been made to highlight the significance of these valuable but

  6. Identifying the Most Appropriate Cultivar for Sustainability of Rice Production System Using Analytic Hierarchy Process (AHP

    Directory of Open Access Journals (Sweden)

    H. Moumenihelali

    2015-09-01

    Full Text Available In general, the ultimate goal of a sustainable system is to maximize the benefits of existing resources and to minimize the threats to the environment that occur due to the present conventional agricultural activities. Meanwhile, seed, as a rice cultivar in the present study, is presented as an important factor in sustainability. Therefore, identifying the most suitable cultivar of rice for sustaining the rice cultivation system is considered to be the main goal of the research. The population of the present study involves all specialists who have enough knowledge on components of sustainability and rice cultivars. To this end, 16 people were identified and studied through non-probability sampling method (purposeful and snowball. Face and content validity was used to determine the validity of the questionnaire. In addition, to assess the reliability, inconsistency ratio was used. Analytical Hierarchy Process (AHP technique was used in order to achieve the main objective, which is to identify the most suitable varieties for sustainable rice cultivation system. Expert Choice 2000 software was applied to calculate the data.The prerequisite of applying AHP technique is to consider the criteria (sustainability of rice cultivation system which include: economical, ecological, technical, social, and policy sustainability and their sub-criteria in the one hand, and decision alternatives (rice cultivars including: Hashemi, Tarom, Neda, Fajr, Khazar and Shirudi in the other hand. The results of prioritizing the criteria of rice cultivation stability showed that the economical (32%, ecological (23.9% and technical (21.1% stability are more important than the stability of social (14.8% and policy (8.3% aspects. Likewise, research findings showed that the cultivars of Hashemi (20.6% and Tarom (20.1% with a slight difference against each other are the most proper cultivars, respectively, in the sustainability of rice cultivation system.

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

    Science.gov (United States)

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

    2014-01-01

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

  8. Signatures of adaptation in the weedy rice genome.

    Science.gov (United States)

    Li, Lin-Feng; Li, Ya-Ling; Jia, Yulin; Caicedo, Ana L; Olsen, Kenneth M

    2017-05-01

    Crop domestication provided the calories that fueled the rise of civilization. For many crop species, domestication was accompanied by the evolution of weedy crop relatives, which aggressively outcompete crops and reduce harvests. Understanding the genetic mechanisms that underlie the evolution of weedy crop relatives is critical for agricultural weed management and food security. Here we use whole-genome sequences to examine the origin and adaptation of the two major strains of weedy rice found in the United States. We find that de-domestication from cultivated ancestors has had a major role in their evolution, with relatively few genetic changes required for the emergence of weediness traits. Weed strains likely evolved both early and late in the history of rice cultivation and represent an under-recognized component of the domestication process. Genomic regions identified here that show evidence of selection can be considered candidates for future genetic and functional analyses for rice improvement.

  9. Contribution of seedling vigour and anoxia/hypoxia-responsive genes to submergence tolerance in Vietnamese lowland rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Hien Thi Thu Vu

    2016-09-01

    Full Text Available A direct-seeded rice cultivation system has been widely adopted in Asian countries. Optimum germination and vigorous seedling growth under submergence are key traits for the practice of direct seeding. We studied the post-germination seedling vigour in Vietnamese lowland rice accessions based on three bio-parameters, shoot elongation growth under five-day submergence in water-filled test-tubes, seedling recovery rate five days after transferring submerged seedlings to pots with soil and seedling survival rate 21 days after sowing seeds in nursery beds and immediate incubation under submergence. A large diversity was found in seedling vigour thus estimated among the accessions. Significantly high correlations were observed among all three bio-parameters, verifying the contribution of seedling vigour to the manifestation of submergence tolerance at this critical stage of rice development. To examine the roles of anoxia/hypoxia-responsive genes, the expression of 17 candidate genes was studied by reverse transcription polymerase chain reaction (RT-PCR and compared between selected vigorous and non-vigorous groups of accessions. Transcripts of all but two genes showed marked accumulation in submerged seedlings. No differences, however, were found between the two contrasting groups. The observed common and coordinate expression of anoxia/hypoxia-induced genes suggests that they might assume roles in attaining baseline tolerance against submergence stress. It was also suggested that some unknown genetic factors are operating in determining cultivar/genotype-specific levels of submergence tolerance as assessed by post-germination seedling vigour.

  10. ECONOMIC ANALYSIS OF SMALL HOLDER RICE PRODUCTION SYSTEMS IN EBONYI STATE SOUTH EAST, NIGERIA

    Directory of Open Access Journals (Sweden)

    Nwaobiala C.U.

    2013-11-01

    Full Text Available Economic analysis of Upland and Swamp rice production in Ebonyi State, South east Nigeria was studied and analyzed in 2011 farming season. Purposive and multistage random sampling technique was used to select agricultural blocks, circles and rice farmers. The sample size was 240 rice farmers (120 Agricultural Development Programme (ADP Upland rice contact farmers and 120 Agricultural Development Programme (ADP Swamp contact rice farmers. Data for the analysis were collected from a structured questionnaire. The result indicates that mean ages of upland rice farmers was 37.3 years while swamp rice farmers had 39.2 years. The mean farming experience for both farmers were 8.5 years (upland rice farmers and 8.8 years (swamp rice farmers with farm sizes of 1.2 and 1.1 hectares for upland rice farmers and swamp rice farmers respectively. Upland rice farmers had an annual farm income of 189,410.00 NGN (1,222USD as against 201,166.00 NGN (1,297.85USD for Swamp rice farmers. The multiple regression (Cobb Douglas estimates of the determinants of output of upland rice showed that coefficients age, farming experience, farm size, variable inputs and farm income were positively signed at given levels of probability while capital inputs was negative. The Cobb Douglas regression estimates of the determinants of output of Swamp rice showed that the coefficients of education, labour cost, farm size, variable inputs and farm income were positively signed and significant at given levels of probability as well as capital inputs which was negative. The result indicates that net profit from Upland rice cultivation was 92,800.00 NGN (598.71USD with a Benefit Cost Ratio of N1.55 (1.56USD. The net profit from Swamp rice cultivation was 132,090.00 NGN (852.19USD and a Benefit Cost Ratio of 1.75 NGN (1.75USD. Access to credit to rice farmers, subsidy on farm inputs, dissemination of improved rice technologies by extension agents and formation of farmer groups were advocated

  11. Low Rice Intake Is Associated with Proteinuria in Participants of Korea National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Lee, Se Jin; Lee, So Young; Sung, Su Ah; Chin, Ho Jun; Lee, Sung Woo

    2017-01-01

    Little is known about the risk factors of proteinuria in the Asian population. On the basis of the association between rice intake patterns and chronic diseases, we hypothesized that rice intake patterns are associated with proteinuria in the Asian population. Data, including data regarding rice intake frequency and dipstick urinalysis results, from the Korea National Health and Nutrition Examination Survey in 1998, 2001, 2005, and 2007 were analyzed. The study involved 19,824 participants who were older than 20 years of age. Low rice intake was defined as consumption of rice ≤ 1 time/day. Proteinuria was defined as dipstick urinalysis protein ≥ 1 positive. Among the 19,824 participants, the prevalence of low rice intake and proteinuria were 17.3% and 2.9%, respectively. The low rice intake group showed a higher rate of proteinuria than the non-low rice intake group did (3.8% vs. 2.7%, P proteinuria was 1.54 (95% confidence interval (CI): 1.25-1.89; P proteinuria in the Asian population, which might have been affected by the associations of low rice intake with high blood pressure and diabetes. Future prospective studies are needed to confirm the results of this study.

  12. Changing Asian American Stereotypes

    Science.gov (United States)

    Salvador-Burris, Juanita

    1978-01-01

    Social science literature on stereotypes is reviewed. Negative stereotypes of Asian Americans are examined and their relationship to Asian American political and economic status and self image is discussed. Specific actions to counter these stereotypes are advocated. (GC)

  13. Obesity and Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

  14. Glaucoma in Asian Populations

    Science.gov (United States)

    ... Involved News About Us Donate In This Section Glaucoma In Asian Populations email Send this article to ... lower than in their Asian counterparts. Normal Tension Glaucoma affects Japanese Japanese populations, however, have a substantially ...

  15. Asian Australian Literatures

    OpenAIRE

    Madsen, Deborah Lea

    2007-01-01

    This article offers an overview of the range of Asian-Australian writers, within the context of changing historical and political conditions, as well as the complexity of defining a single category of literature written by Australians of Asian heritage. Such a category is difficult to define in strictly nationalistic terms as ‘Asian Australian literature’: where Australian literature is the controlling noun and ‘Asian’ functions as an adjective. Some Asian Australian writers are Australian-bo...

  16. Mapping and characterizing mangrove rice growing environments in West-Africa using remote sensing and secondary data

    NARCIS (Netherlands)

    Adefurin, O.; Hamdy, M; Zwart, S.J.

    2016-01-01

    Rice is one of the major staple foods consumed in Africa and its demand continues to increase as a result of population growth, urbanization and changing diets. Mangrove rice cultivation is of importance along the West-African Atlantic coast from Senegal and Gambia down to Guinea-Bissau,

  17. Rice Agriculture in the River Parishes: The Historical Archeology of the Vacherie Site (16 SJ 40), St. James Parish, Louisiana

    Science.gov (United States)

    1990-09-01

    India Company to request additional rice seed and slaves knowledgeable about rice cultivation. Botanical evidence supports the theory that the first...use. Besides coins and keys, this group included items of cosmetic and personal hygiene, such as combs and brushes, and all writing materials. The only

  18. 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

  19. Remote sensing based change analysis of rice environments in Odisha, India.

    Science.gov (United States)

    Gumma, Murali Krishna; Mohanty, Samarendu; Nelson, Andrew; Arnel, Rala; Mohammed, Irshad A; Das, Satya Ranjan

    2015-01-15

    The rainfed rice-growing environment is perhaps one of the most vulnerable to water stress such as drought and floods. It is important to determine the spatial extent of the stress-prone areas to effectively and efficiently promote proper technologies (e.g., stress-tolerant varieties) to tackle the problem of sustainable food production. This study was conducted in Odisha state located in eastern India. Odisha is predominantly a rainfed rice ecosystem (71% rainfed and 29% canal irrigated during kharif-monsoon season), where rice is the major crop and staple food of the people. However, rice productivity in Odisha is one of the lowest in India and a significant decline (9%) in rice cultivated area was observed in 2002 (a drought year). The present study analyzed the temporal rice cropping pattern in various ecosystems and identified the stress-prone areas due to submergence (flooding) and water shortage. The spatial distribution of rice areas was mapped using MODIS (MOD09Q1) 250-m 8-day time-series data (2000-2010) and spectral matching techniques. The mapped rice areas were strongly correlated (R(2) = 90%) with district-level statistics. Also the class accuracy based on field-plot data was 84.8%. The area under the rainfed rice ecosystem continues to dominate, recording the largest share among rice classes across all the years. The use of remote-sensing techniques is rapid, cost-effective, and reliable to monitor changes in rice cultivated area over long periods of time and estimate the reduction in area cultivated due to abiotic stress such as water stress and submergence. Agricultural research institutes and line departments in the government can use these techniques for better planning, regular monitoring of land-use changes, and dissemination of appropriate technologies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Produtividade do arroz irrigado por aspersão em função do espaçamento e da densidade de semeadura Yield of upland rice cultivated under sprinkler irrigation as a function of row spacing and seed density

    Directory of Open Access Journals (Sweden)

    CARLOS ALEXANDRE COSTA CRUSCIOL

    2000-06-01

    Full Text Available Com o objetivo de estudar o efeito de três espaçamentos entre fileiras (30, 40 e 50 cm e três densidades de semeadura (100, 150 e 200 sementes viáveis/m² sobre o desenvolvimento da planta, os componentes da produção e a produtividade do arroz irrigado por aspersão até a tensão de reposição de água de -0,070 MPa, foi instalado um experimento em condições de campo, em um Latossolo Vermelho-Escuro, epieutrófico, textura argilosa, em Selvíria, MS. A cultivar avaliada foi a IAC 201. Esta cultivar apresenta suscetibilidade ao acamamento, no sistema de irrigação por aspersão, até uma tensão de reposição de água, no solo, de -0,070 Mpa. O número de colmos e de panículas é incrementado com a redução do espaçamento. A densidade de 100 sementes/m² é a mais indicada para a cultivar IAC 201 irrigada por aspersão, por proporcionar menor gasto de sementes. O espaçamento de 30 cm entre fileiras de plantas proporciona maior produtividade de grãos da cultivar IAC 201 no sistema de irrigação por aspersão.Plant development, plant phenology, yield components and grain yield of upland rice, cv. IAC 201, submitted to three different row spacings (30, 40 and 50 cm and densities (100, 150 and 200 viable seeds/m² were studied. The experiment was set under field conditions in a Dark-Red Latosol, loamy texture, in Selvíria, MS, Brazil, under sprinkler irrigation conditions with water replacement tension of -0.070 MPa. The number of stalks and panicles per area increased with row spacing reduction; density of 100 viable seeds/m² is more indicated for IAC 201 cultivated under sprinkler irrigation conditions, because seed spend is smaller; row spacing of 30 cm allowed the maximum grain yield.

  1. Meloidogyne graminicola: a major threat to rice agriculture.

    Science.gov (United States)

    Mantelin, Sophie; Bellafiore, Stéphane; Kyndt, Tina

    2017-01-01

    Superkingdom Eukaryota; Kingdom Metazoa; Phylum Nematoda; Class Chromadorea; Order Tylenchida; Suborder Tylenchina; Infraorder Tylenchomorpha; Superfamily Tylenchoidea; Family Meloidogynidae; Subfamily Meloidogyninae; Genus Meloidogyne. Microscopic non-segmented roundworm. Plant pathogen; obligate sedentary endoparasitic root-knot nematode. Reproduction: facultative meiotic parthenogenetic species in which amphimixis can occur at a low frequency (c. 0.5%); relatively fast life cycle completed in 19-27 days on rice depending on the temperature range. Reported to infect over 100 plant species, including cereals and grass plants, as well as dicotyledonous plants. Main host: rice (Oryza sativa). Characteristic hook-shaped galls (root swellings), mainly formed at the root tips of infected plants. Alteration of the root vascular system causes disruption of water and nutrient transport, stunting, chlorosis and loss of vigour, resulting in poor growth and reproduction of the plants with substantial yield losses in crops. Nematicides, chemical priming, constant immersion of rice in irrigated fields, crop rotation with resistant or non-host plants, use of nematode-free planting material. Some sources of resistance to Meloidogyne graminicola have been identified in African rice species (O. glaberrima and O. longistaminata), as well as in a few Asian rice cultivars. Major threat to rice agriculture, particularly in Asia. Adapted to flooded conditions, Meloidogyne graminicola causes problems in all types of rice agrosystems. © 2016 BSPP and John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    Ana L Caicedo

    2007-09-01

    Full Text Available 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 the dominant demographic model for domesticated species, cannot explain the derived nucleotide polymorphism site frequency spectrum in rice. Instead, a bottleneck model that incorporates selective sweeps, or a more complex demographic model that includes subdivision and gene flow, are more plausible explanations for patterns of variation in domesticated rice varieties. If selective sweeps are indeed the explanation for the observed nucleotide data of domesticated rice, it suggests that strong selection can leave its imprint on genome-wide polymorphism patterns, contrary to expectations that selection results only in a local signature of variation.

  3. Indica rice genome assembly, annotation and mining of blast disease resistance genes.

    Science.gov (United States)

    Mahesh, H B; Shirke, Meghana Deepak; Singh, Siddarth; Rajamani, Anantharamanan; Hittalmani, Shailaja; Wang, Guo-Liang; Gowda, Malali

    2016-03-16

    Rice is a major staple food crop in the world. Over 80% of rice cultivation area is under indica rice. Currently, genomic resources are lacking for indica as compared to japonica rice. In this study, we generated deep-sequencing data (Illumina and Pacific Biosciences sequencing) for one of the indica rice cultivars, HR-12 from India. We assembled over 86% (389 Mb) of rice genome and annotated 56,284 protein-coding genes from HR-12 genome using Illumina and PacBio sequencing. Comprehensive comparative analyses between indica and japonica subspecies genomes revealed a large number of indica specific variants including SSRs, SNPs and InDels. To mine disease resistance genes, we sequenced few indica rice cultivars that are reported to be highly resistant (Tetep and Tadukan) and susceptible (HR-12 and Co-39) against blast fungal isolates in many countries including India. Whole genome sequencing of rice genotypes revealed high rate of mutations in defense related genes (NB-ARC, LRR and PK domains) in resistant cultivars as compared to susceptible. This study has identified R-genes Pi-ta and Pi54 from durable indica resistant cultivars; Tetep and Tadukan, which can be used in marker assisted selection in rice breeding program. This is the first report of whole genome sequencing approach to characterize Indian rice germplasm. The genomic resources from our work will have a greater impact in understanding global rice diversity, genetics and molecular breeding.

  4. Farmer’s Knowledge and Perceptions on Rice Insect Pests and Their Management in Uganda

    Directory of Open Access Journals (Sweden)

    Simon Alibu

    2016-08-01

    Full Text Available Rice is a new crop in Uganda, but has quickly grown in importance. Between 2000 and 2010, total area under rice cultivation in the country grew by 94% from 140,000 ha. Changes in the agro ecosystem due to expansion in rice area may have altered the pest status of rice insect pests. However, far too little attention has been paid to assessing the prevalence and importance of rice insect-pests in Uganda. In this study, we interviewed 240 lowland-rice farming households from eight districts within the north, east and central regions of Uganda about their perceived insect-pest problems and control measures employed, if any. A semi-structured questionnaire was used. The farmers ranked rice insect pests as the most important biotic constraint in rice production, with stem borers and the African rice gall midge (AfRGM perceived to be the 1st and 2nd most detrimental insect pests, respectively. In spite of this, only 36% of the respondents could positively identify symptoms of AfRGM damage on rice plants, while 64% were familiar with stem borer damage. Over 60% of interviewed farmers expressed confidence in the effectiveness of insecticides for controlling rice insect pests. Cultural control measures were not popular among the farmers.

  5. Comparison of saccharification and fermentation of steam exploded rice straw and rice husk.

    Science.gov (United States)

    Wood, Ian P; Cao, Huong-Giang; Tran, Long; Cook, Nicola; Ryden, Peter; Wilson, David R; Moates, Graham K; Collins, Samuel R A; Elliston, Adam; Waldron, Keith W

    2016-01-01

    Rice cultivation produces two waste streams, straw and husk, which could be exploited more effectively. Chemical pretreatment studies using rice residues have largely focussed on straw exploitation alone, and often at low substrate concentrations. Moreover, it is currently not known how rice husk, the more recalcitrant residue, responds to steam explosion without the addition of chemicals. The aim of this study has been to systematically compare the effects of steam explosion severity on the enzymatic saccharification and simultaneous saccharification and fermentation of rice straw and husk produced from a variety widely grown in Vietnam (Oryza sativa, cv. KhangDan18). Rice straw and husk were steam exploded (180-230 °C for 10 min) into hot water and washed to remove fermentation inhibitors. In both cases, pretreatment at 210 °C and above removed most of the noncellulosic sugars. Prolonged saccharification at high cellulase doses showed that rice straw could be saccharified most effectively after steam explosion at 210 °C for 10 min. In contrast, rice husk required more severe pretreatment conditions (220 °C for 10 min), and achieved a much lower yield (75 %), even at optimal conditions. Rice husk also required a higher cellulase dose for optimal saccharification (10 instead of 6 FPU/g DM). Hemicellulase addition failed to improve saccharification. Small pilot scale saccharification at 20 % (w/v) substrate loading in a 10 L high torque bioreactor resulted in similarly high glucose yields for straw (reaching 9 % w/v), but much less for husk. Simultaneous saccharification and fermentation under optimal pretreatment and saccharification conditions showed similar trends, but the ethanol yield from the rice husk was less than 40 % of the theoretical yield. Despite having similar carbohydrate compositions, pretreated rice husk is much less amenable to saccharification than pretreated rice straw. This is likely to attenuate its use as a biorefinery

  6. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    Directory of Open Access Journals (Sweden)

    Yu-zhu ZHANG

    2011-09-01

    Full Text Available The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control. The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological environment of rice population, a significant reduction under the rice canopy temperature, especially during high-temperature periods. Rice plants under mulching cultivation conditions displayed a stronger transpiration and lower leaf temperature, thereby improving the ability of anti-high temperature stress and markedly increasing the photosynthetic rate. Furthermore, the yield components of rice were significantly optimized under mulching cultivation, of which with plastic film mulching displayed the highest grain number per panicle and seed-setting rate, and a yield increase of 16.81% compared with the control; and with straw mulching displayed an increase of effective panicle number and a 9.59% increase of total yield compared to the control.

  7. IMPACT OF MARKET-DETERMINED EXCHANGE RATES ON RICE PRODUCTION AND IMPORT IN NIGERIA

    Directory of Open Access Journals (Sweden)

    Aliyu Aishat Ammani

    2013-10-01

    Full Text Available Rice is an economically important food security crop, cultivated in almost all of Nigeria’s 36 States. Nigeria spends more than 356 billion naira (2.24 billion US dollars annually on rice import. This paper set out to analyze the trend in rice production, productivity, import, value of import and consumption that follows the adoption of the Structural Adjustment Programme (SAP in Nigeria, with emphasis on the effects of exchange rate (ER deregulation on domestic rice production and rice imports over the period 1986-2010. Relevant time series data were collected and used. A semi-log growth rate model and 2simple linear regression models were developed and estimated. Highlights of the findings include (i accelerated rate of growth in rice production (Instantaneous Growth Rate (IGR 2.2%; Cumulative Growth Rate (CGR 2.2%; rice hectarage (IGR 3.7%; CGR 3.8%; rice importation (IGR 8.5%; CGR8.9%; expenditure on rice importation (IGR 10.6%; CGR 11.2% and rice consumption (IGR 3.4%; CGR 3.5% alongside a significant deceleration in rice yield (IGR -1.4%; CGR -201.4% (ii The observed significant increase in domestic rice production cannot be confidently attributed to ER deregulation alone because it does not lead to a decrease in rice importation into Nigeria. (iii The significant increase in domestic rice importation as observed contradicts a priori expectation that ER deregulation will lead to significant decrease in rice importation. The study concluded that free market approach alone cannot stimulate local agricultural production in countries where farmers producing under low-technology-agriculture are put in direct competition with farmers from advancedtechnology-agriculture; hence governments need to restrict importation to protect local producers.

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

    OpenAIRE

    Saleh, Mohammed; Meullenet, Jean-Francois

    2013-01-01

    Rice milling plays a key factor in determining rice quality and value. Therefore accurate quality assessments are critical to the rice industry. This study was undertaken to assess the effect of exposing rice to elevated temperatures during milling, on cooked rice texture and rice flour pasting properties. Two long (Cybonnett and Francis) and one medium (Jupiter) rice (oryzae sativa L.) cultivars were milled using McGill laboratory mill for 30 and 40 s after warmed up the mill before milling....

  9. Ecological balance between supply and demand based on cultivated land ecological footprint method in Guizhou Province

    Science.gov (United States)

    Qian, Qinghuan; Zhou, Dequan; Bai, Xiaoyong; Xiao, Jianyong; Chen, Fei; Zeng, Cheng

    2018-01-01

    In order to construct the indicators of the balance between supply and demand of the cultivated land ecological carrying capacity, basing on the relation of the cultivated land ecological carrying capacity supply and demand, applying the model of Cultivated Land Ecological Footprints and the method of CIS and considering the factors of cultivated land production, taking the statistical data of 2015 as an example, and then made a systematic evaluation of the balance between supply and demand of the cultivated land ecological carrying capacity in Guizhou Province. The results show that (1) the spatial distribution of supply and demand of cultivated land ecological carrying capacity in Guizhou is unbalanced, and the northern and eastern parts are the overloading area, the middle, the south and the west parts are the balance area. (2) From the perspective of cultivated land structure, the crops with ecological carrying capacity surplus were rice, vegetables and peanuts, among which rice was the highest and the ecological balance index was 0.7354. The crops with ecological carrying capacity overload were potato, wheat, maize, rapeseeds, soybeans and cured tobacco, of which the index of potato up to 7.11, other types of indices are less than 1.5. The research can provide the ecological security early warning, the overall plan of land use and sustainable development of the area cultivated land with scientific evidence and decision support.

  10. Rice husk-originating silicon-graphite composites for advanced lithium ion battery anodes

    Science.gov (United States)

    Kim, Hye Jin; Choi, Jin Hyeok; Choi, Jang Wook

    2017-09-01

    Rice husk is produced in a massive amount worldwide as a byproduct of rice cultivation. Rice husk contains approximately 20 wt% of mesoporous SiO2. We produce mesoporous silicon (Si) by reducing the rice husk-originating SiO2 using a magnesio-milling process. Taking advantage of meso-porosity and large available quantity, we apply rice husk-originating Si to lithium ion battery anodes in a composite form with commercial graphite. By varying the mass ratio between these two components, trade-off relation between specific capacity and cycle life was observed. A controllable pre-lithiation scheme was adopted to increase the initial Coulombic efficiency and energy density. The series of electrochemical results suggest that rice husk-originating Si-graphite composites are promising candidates for high capacity lithium ion battery anodes, with the prominent advantages in battery performance and scalability.

  11. Genomic variation associated with local adaptation of weedy rice during de-domestication

    Science.gov (United States)

    Qiu, Jie; Zhou, Yongjun; Mao, Lingfeng; Ye, Chuyu; Wang, Weidi; Zhang, Jianping; Yu, Yongyi; Fu, Fei; Wang, Yunfei; Qian, Feijian; Qi, Ting; Wu, Sanling; Sultana, Most Humaira; Cao, Ya-Nan; Wang, Yu; Timko, Michael P.; Ge, Song; Fan, Longjiang; Lu, Yongliang

    2017-01-01

    De-domestication is a unique evolutionary process by which domesticated crops are converted into ‘wild predecessor like' forms. Weedy rice (Oryza sativa f. spontanea) is an excellent model to dissect the molecular processes underlying de-domestication. Here, we analyse the genomes of 155 weedy and 76 locally cultivated rice accessions from four representative regions in China that were sequenced to an average 18.2 × coverage. Phylogenetic and demographic analyses indicate that Chinese weedy rice was de-domesticated independently from cultivated rice and experienced a strong genetic bottleneck. Although evolving from multiple origins, critical genes underlying convergent evolution of different weedy types can be found. Allele frequency analyses suggest that standing variations and new mutations contribute differently to japonica and indica weedy rice. We identify a Mb-scale genomic region present in weedy rice but not cultivated rice genomes that shows evidence of balancing selection, thereby suggesting that there might be more complexity inherent to the process of de-domestication. PMID:28537247

  12. A Methodological Investigation of Cultivation.

    Science.gov (United States)

    Rubin, Alan M.; And Others

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

  13. 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

    African and Asian populations of Fusarium spp. (Gibberella fujikuroi species complex) associated with Bakanae of rice (Oryzae sativa L.) were isolated from seeds and characterized with respect to ecology, phylogenetics, pathogenicity and mycotoxin production. Independent of the origin, Fusarium spp....... were detected in the different rice seed samples with infection rate ranges that varied from 0.25% to 9%. Four Fusaria (F. andiyazi, F. fujikuroi, F. proliferatum and F. verticillioides) were found associated with Bakanae of rice. While three of the Fusaria were found in both African and Asian seed....... 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....

  14. Variations in nutrient and trace element composition of rice in an organic rice-frog coculture system.

    Science.gov (United States)

    Sha, Zhimin; Chu, Qingnan; Zhao, Zheng; Yue, Yubo; Lu, Linfang; Yuan, Jing; Cao, Linkui

    2017-11-16

    Introducing frogs into paddy fields can control pests and diseases, and organic farming can improve soil fertility and rice growth. The aim of this 2-year field study was compare the yield and elemental composition of rice between an organic farming system including frogs (ORF) and a conventional rice culture system (CR). The grain yields were almost the same in the ORF system and the CR system. The ORF significantly increased the contents of phosphorus (P), ion (Fe), zinc (Zn), molybdenum (Mo) and selenium (Se) in rice grain at one or both years. However, the ORF system decreased the calcium (Ca) content in grice grains, and increased the concentration of cadmium, which is potentially toxic. A principal components analysis showed the main impacts of ORF agro-ecosystem on the rice grain ionome was to increase the concentration of P and trace metal(loid)s. The results showed that the ORF system is an ecologically, friendly strategy to avoid excessive use of chemical fertilizers, herbicides and pesticides without decreasing yields, and to improve the nutritional status of rice by increasing the micronutrient contents. The potential risks of increasing Cd contents in rice grain should be addressed if this cultivation pattern is used in the long term.

  15. Deciphering DNA methylation under heat stress in contrasting rice genotypes

    OpenAIRE

    Fradique, João Manuel Silva, 1988-

    2012-01-01

    Tese de mestrado. Biologia (Biologia Evolutiva e do Desenvolvimento). Universidade de Lisboa, Faculdade de Ciências, 2012 Rice is one of the foremost crops in the history of humanity and today it feeds billions of people worldwide, as it is the second most cultivated crop. However, rice can be affected by various environmental stresses. Global climatic models predict a gradual increase in temperature by an average of 2-4ºC by the end of this century (IPCC, 2007). Thus, future climates with...

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

    Science.gov (United States)

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

    2010-05-01

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

  17. Soil erosion from shifting cultivation and other smallholder land use in Sarawak, Malaysia

    DEFF Research Database (Denmark)

    Neergaard, Andreas de; Magid, Jakob; Mertz, Ole

    2008-01-01

    to compare soil erosion from three land use types in a shifting cultivation system, namely upland rice, pepper gardens and native forest. We used two sample sites within the humid tropical lowland zone in Sarawak, Malaysia. Both areas had steep slopes between 25° and 50°, and were characterised by a mosaic...

  18. Rice that Filipinos Grow and Eat

    OpenAIRE

    de Leon, John C.

    2011-01-01

    This paper introduces rice to the reader and analyzes the changes it has gone through these past 100 years in the shaping hands of varietal improvement science. Here, the richness of the crop as a genetic material and resource is revealed. Landrace rice, pureline selection rice, crossbred rice, semidwarf rice, hybrid rice, new plant type rice, designer rice - from the traditional to modern to futuristic - rice becomes all of these while traversing time in the Philippines. There is rice for th...

  19. Environmental Life Cycle Assessment of long-term organic rice production in a Subtropical area of China

    DEFF Research Database (Denmark)

    Xueqing, He; Qiao, Yuhui; Liang, Long

    2018-01-01

    conversion and compare it to conventional rice (CR) in subtropical China. The life cycle assessment (LCA) method was used to assess environmental impact of rice production systems with regard to nine environmental impact categories: Non-renewable Energy Depletion (NED), Water Depletion (WD), Land Occupation......Organic farming is considered as a promising solution for reducing the environmental burden related to agricultural practices. China is one of the top-five countries with the largest organic area in the world and produces a major part of the world's organic rice. Rice cultivation causes...... a considerable environmental impact and changing from conventional to organic rice cultivation might therefore have a potentially great impact. Meanwhile, it takes time for the organic farming systems to reach a new steady state after conversion to organic. Thus, the environmental profile of the organic products...

  20. Osteoporosis and Asian American Women

    Science.gov (United States)

    ... Breadcrumb Home Osteoporosis Osteoporosis and Asian American Women Osteoporosis and Asian American Women Asian American women are ... Are Available? Resources For Your Information What Is Osteoporosis? Osteoporosis is a condition in which the bones ...

  1. The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah

    OpenAIRE

    CARVALHO, M. T. de M.

    2015-01-01

    Abstract Keywords: tropical Savannah, biochar, soil fertility, aerobic rice, grain yield, N2O emission Márcia Thaís de Melo Carvalho (2015). The impact of wood biochar as a soil amendment in aerobic rice systems of the Brazilian Savannah. PhD thesis, Wageningen University, The Netherlands, with summaries in English, Dutch and Portuguese,  160 pp. Rice is a staple food for 3 billion people in the world. In Brazil, rice is a traditional staple food mostly cultivated by smallh...

  2. Microbial Activity and Silica Degradation in Rice Straw

    Science.gov (United States)

    Kim, Esther Jin-kyung

    increased. Silicase activity did not change across nitrogen treatments despite a shift in microbial community with varied nitrogen concentration. Samples treated with different nitrogen concentrations had similar levels of diversity, however the microbial community composition differed with added nitrogen. The results demonstrated that adding nitrogen to rice straw during thermophilic decomposition nurtured a more active microbial community and promoted enzyme secretion thus improving the ability to discover enzymes for rice straw deconstruction. These results can inform future experiments for cultivating a unique, thriving compost-derived microbial community that can successfully decompose rice straw. Understanding the silicase activity of microorganisms may alleviate the challenges associated with silica in various feedstocks.

  3. Agronomic performance of F1, F2 and F3 hybrids between weedy rice and transgenic glufosinate-resistant rice.

    Science.gov (United States)

    Song, Xiaoling; Wang, Zhou; Qiang, Sheng

    2011-08-01

    Studies of hybrid fitness, of which agronomic performance may be an indicator, can help in evaluating the potential for introgression of a transgene from a transgenic crop to wild relatives. The objective of this study was to assess the agronomic performance of reciprocal hybrids between two transgenic glufosinate-resistant rice lines, Y0003 and 99-t, and two weedy rice accessions, WR1 and WR2, in the greenhouse. F1 hybrids displayed heterosis in height, flag leaf area and number of spikelets per panicle. The agronomic performance of F1 between WR1 and Y0003 was not affected by crossing direction. The tiller and panicle numbers of F1 individuals were higher than their F2 counterparts. However, these traits did not change significantly from the F2 to the F3 generation or in hybrids with weedy rice as maternal or paternal plants. For all hybrids, the in vitro germination rates of fresh pollen were similar and significantly lower than those of their parents, seed sets were similar to or of lower value than those of weedy rice parents and seed shattering characteristics were partially suppressed, but the survival of hybrids over winter in the field was similar to that of weedy rice parents. All F1, F2 and F3 hybrids had similar composite agronomic performance to weedy rice parents. There was no significant decrease in the composite agronomic performance of any of the hybrids compared with weedy rice. This implies that gene flow from transgenic cultivated rice to weedy rice could occur under natural conditions. Copyright © 2011 Society of Chemical Industry.

  4. Transition in nori cultivation

    DEFF Research Database (Denmark)

    Delaney, Alyne

    2011-01-01

    of social and environmental sustainability, we must understand both society and cultural institutions. With this in mind, this article focuses on the division of labor among cultivators, particularly along gender lines and the impacts, on a cultural level, of technological change on nori production...

  5. Cultivating the Grapevine.

    Science.gov (United States)

    Rauschenberg, Gretchen

    1988-01-01

    Although administrators may view grapevines as threats to established leadership, informal communication is necessary to keep an organization functioning smoothly. No one can completely control the grapevine or its accuracy, but astute administrators can learn to cultivate and use informal communication systems wisely. (MLH)

  6. Estrutura fitossociológia de um fragmento natural de floresta inundável em área de orizicultura irrigada, município de Lagoa da Confusão, Tocantins Phytosociologial structure of a natural fragment of floodplain forest in area of irrigated rice cultivation, municipal district of Lagoa da Confusão, Tocantins, Brazil

    Directory of Open Access Journals (Sweden)

    Elizabeth Rodrigues Brito

    2006-10-01

    , inserted in area of irrigated rice cultivation. For the phytosociological survey, all the tree/shrub individuals with perimeter at 1.30m (PBH > 15 cm were sampled. On the whole, 807 individuals, 35 families and 70 species were sampled. The species with higher VC, in descending order, were Hirtella racemosa Lam., Qualea multiflora Mart. and Cecropia pachystachya Trécul. The richest families in species were Fabaceae (9, Vochysiaceae (6, Annonaceae and Malvaceae (4. The Shannon diversity index (H' was 3.44. The distribution of diameter classes showed an inverted "J" curve, with most of the individuals being in the first class.

  7. Chemical Safety of Unpolished Nigerian Rice

    Directory of Open Access Journals (Sweden)

    Akinsola Francis Awopetu

    2017-03-01

    Full Text Available Levels of arsenic (As, lead (Pb, cadmium (Cd, calcium (Ca, chromium (Cr, potassium (K, sodium (Na, and zinc (Zn in locally cultivated rice consumed in Ondo and Ekiti States of Nigeria were investigated. The rice samples were obtained from six different rice-producing towns; Akure, Ondo, Ado, Igbemo, Ikole and Erinjiyan. The estimated dietary intake (EDI of these elements were determined and compared with the provisional tolerable daily intake (PTDI and dietary reference intake (DRI values for toxic and essential elements respectively. The measured mean levels of Pb, As, Cr, Cd, Zn, Na, Ca and K were 0.047 ± 0.007, 0.041 ± 0.004, 0.570 ± 0.032, 0.026 ± 0.003, 7.856 ± 0.659, 42.15 ± 0.191, 337.11 ± 0.315, and 2650.09 ± 0.337 µg/g respectively while the average EDI were 00.101 ± 0.042 µg/day, 0.088 ± 0.14µg/day, 1.234 ± 0.045 µg/day, 0.057 ± 0.002 µg/day, 0.017 ± 0.071 mg/day, 0.091 ± 0.013 mg/day, 0.73 ± 0.018 mg/day and 5.742 ± 0.337 mg/day respectively. The EDIs were not significantly higher than the reference values for the elements except Cr. Also the rice samples were not rich enough in sodium, calcium and potassium compared to the dietary reference intakes for these elements. It is recommended that rice diets should be supplemented with other food items such as meat, fruits and vegetables.

  8. Determinants for grading Malaysian rice

    Science.gov (United States)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

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

  9. Emerging Asian Economics.

    Science.gov (United States)

    Trezise, Philip H.

    What we can expect in the future from the miracle economies of Japan, South Korea, Taiwan, Singapore, and Hong Kong, whether they pose a threat to the older industrial states of Western Europe and North American, and whether China is to be the next emerging Asian economy are discussed. The amazing economic recovery of these East Asian countries…

  10. Glycemic index of American-grown jasmine rice classified as high.

    Science.gov (United States)

    Truong, Teresa H; Yuet, Wei Cheng; Hall, Micki D

    2014-06-01

    The primary objective was to determine the glycemic index (GI) of jasmine rice grown in the United States (US). Secondary objective was to compare the GI of US grown jasmine rice to those grown in Thailand. Twelve healthy subjects were served all four brands of jasmine rice and a reference food (glucose), each containing 50 g of available carbohydrate. Fingerstick blood glucose was measured at 0, 15, 30, 45, 60, 90, and 120 min after consumption following a fasting state. The GI was calculated using the standard equation. The GI values for test foods ranged from 96 to 116 and were all classified as high GI foods. No difference in GI was found between American-grown and Thailand-grown jasmine rice. Although not statistically significant, observations show glycemic response among Asian American participants may be different. GI should be considered when planning meals with jasmine rice as the main source carbohydrate.

  11. Molecular Basis and Regulation of Ammonium Transporter in Rice

    Directory of Open Access Journals (Sweden)

    Bao-zhen LI

    2009-12-01

    Full Text Available Rice grows in flooded paddy fields and takes up ammonium as the preferred nitrogen (N source. Ammonium uptake is facilitated by a family of integral membrane proteins known as ammonium transporters found in all domains of life. However, the molecular mechanism and functional characteristics of the ammonium transporters (AMT in rice have not been determined in detail yet. In this review, we report a genome-wide search for AMT genes in rice, resulting in the increase of the number of potential AMT proteins to at least 12, including members of both the alpha and beta sub-groups. Analysis of the predicted protein sequences for the 12 OsAMT proteins identified many conserved phosphorylation sites in both the alpha and beta group members, which could potentially play a role in controlling the activity of the transporters. Present knowledge of the expression of rice AMT genes is also summarized in detail. Future studies should focus on the structural and functional characteristics of OsAMT proteins to provide insight into the mechanism of ammonium uptake and its regulation in rice. Such research could improve utilization and decrease wastage of N fertilizer in rice cultivation.

  12. Microbial community structure in the rhizosphere of rice plants

    Directory of Open Access Journals (Sweden)

    Björn eBreidenbach

    2016-01-01

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

  13. Potential of rice straw for bio-refining: An overview.

    Science.gov (United States)

    Abraham, Amith; Mathew, Anil Kuruvilla; Sindhu, Raveendran; Pandey, Ashok; Binod, Parameswaran

    2016-09-01

    The biorefinery approach for the production of fuels and chemicals is gaining more and more attraction in recent years. The major advantages of biorefineries are the generation of multiple products with complete utilization of biomass with zero waste generation. Moreover the process will be economically viable when it targets low volume high value products in addition to high volume low value products like bioethanol. The present review discuss about the potential of rice straw based biorefinery. Since rice is a major staple food for many Asian countries, the utilization of the rice straw residue for fuel and chemicals would be very economical. The review focuses the availability and the potential of this residue for the production of fuel and other high value chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The Representation of Older People in East Asian Television Advertisements.

    Science.gov (United States)

    Prieler, Michael; Ivanov, Alex; Hagiwara, Shigeru

    2017-06-01

    In this study, 432 television advertisements from Hong Kong, Japan, and South Korea were analyzed to determine their representations of older people. Findings demonstrate that in East Asian advertisements, older people are highly underrepresented, appear in major roles, mostly alongside younger people, and older men clearly outnumber older women. The other variables investigated (i.e., setting and product categories) led to no conclusive findings for the three societies. In short, our study, employing ethnolinguistic vitality theory to analyze television advertisements, demonstrates how East Asian societies greatly marginalize older people. Potential effects of such representations are discussed using social cognitive theory and cultivation theory.

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

    Science.gov (United States)

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

    2016-02-01

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

  16. Studies on mosquitoes (Diptera: Culicidae and anthropicenvironment: 5- Breeding of Anopheles albitarsis in flooded rice fields in South-Eastern Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1994-10-01

    Full Text Available Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small. That inverse correlation may give potential direction to control measures.

  17. 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...

  18. economics of rice production

    African Journals Online (AJOL)

    ABSTRACT. Local rice production is being promoted in Ghana to reduce the' dependence on im- ports, ensure stable low-prices food for the population and also create employment. This paper examines three rice production systems; Upland, Valley Bottom and Irri- gated, in the Upper East Region of Ghana with a view to ...

  19. Consumers' Preferences for a Local Food Product: The Case of a New Carnaroli Rice Product in Lombardy.

    Science.gov (United States)

    Ferrazzi, Giovanni; Ventura, Vera; Ratti, Sabrina; Balzaretti, Claudia

    2017-04-13

    Italy, with a cultivated area of 218,000 ha, is a European leader of rice production. In particular Lombardy region accounts for 40% of total rice cultivation and the case study in object accounts for 3.2% of Lombardy total rice area (2773 ha). Starting from 2012, through a regional project titled Buono, Sano e Vicino (good, healthy and close), Riso e Rane rural district supported local rice farmers in developing innovation in rice production and promoting an alternative supply chain to increase farmers bargaining power and promote new market strategies. More specifically, the innovation introduced is a new biotech method for variety certification, named DNA controllato (DNA tested). In the first step of the project, the attention was focused on an Italian traditional variety of rice: Carnaroli rice. Thanks to a commercial agreement with one of the most important large retailers in Lombardy, the Riso e Rane rice is offered for sale both in the traditional and wholegrain version. In this context, this work aims to evaluate the determinants of consumer's quality perception of this product, through a preference study of the commercial rice package. Preliminary results reveal that consumers perceive information about origin, local food-system and tradition more easily than DNA tested certification. In conclusion, this work contributes to evaluate the role of bio economy applications to the food sector and offers new insights for the debate about the relationships between tradition and innovation.

  20. Estimating Rice Yield under Changing Weather Conditions in Kenya Using CERES Rice Model

    Directory of Open Access Journals (Sweden)

    W. O. Nyang’au

    2014-01-01

    Full Text Available Effects of change in weather conditions on the yields of Basmati 370 and IR 2793-80-1 cultivated under System of Rice Intensification (SRI in Mwea and Western Kenya irrigation schemes were assessed through sensitivity analysis using the Ceres rice model v 4.5 of the DSSAT modeling system. Genetic coefficients were determined using 2010 experimental data. The model was validated using rice growth and development data during the 2011 cropping season. Two SRI farmers were selected randomly from each irrigation scheme and their farms were used as research fields. Daily maximum and minimum temperatures and precipitation were collected from the weather station in each of the irrigation schemes while daily solar radiation was generated using weatherman in the DSSAT shell. The study revealed that increase in both maximum and minimum temperatures affects Basmati 370 and IR 2793-80-1 grain yield under SRI. Increase in atmospheric CO2 concentration led to an increase in grain yield for both Basmati and IR 2793-80-1 under SRI and increase in solar radiation also had an increasing impact on both Basmati 370 and IR 2793-80-1 grain yield. The results of the study therefore show that weather conditions in Kenya affect rice yield under SRI and should be taken into consideration to improve food security.

  1. [Dendrobium officinale stereoscopic cultivation method].

    Science.gov (United States)

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

    2014-12-01

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

  2. Greenhouse gas budget from a rice paddy field in the Albufera of Valencia, Spain.

    Science.gov (United States)

    Meijide, Ana; López-Ballesteros, Ana; Calvo-Roselló, Esperanza; López-Jiménez, Ramón; Recio-Huetos, Jaime; Calatayud, Vicent; Carrara, Arnaud; Serrano-Ortiz, Penelope

    2017-04-01

    Rice paddy fields are large sources of anthropogenic methane (CH4) and therefore many studies have assessed CH4 fluxes from rice paddy fields, mainly in Asia where most of the rice cultivation takes place. However, rice is also cultivated in the Mediterranean, where climatic and management conditions greatly differ. In the Albufera of Valencia, the largest freshwater lagoon in Spain, rice paddy fields have the particularity of being flooded not only while the rice grows, but also after the harvest during the winter. These flooding conditions might result in emissions which are very specific of this ecosystem, and cannot be extrapolated from other studies. We studied CH4 fluxes in a rice paddy field in the Albufera of Valencia at different stages of rice cultivation using the eddy covariance technique and static chambers. We additionally measured carbon dioxide (CO2), water fluxes and nitrous oxide (N2O) fluxes with eddy covariance and chamber methods respectively, in order to obtain a full greenhouse gas (GHG) budget. Our study also aimed at providing a mechanistic understanding of GHG emissions at different stages of rice cultivation, and therefore we also used the Enhanced and Normalized Vegetation Indexes (EVI and NDVI, respectively), derived from remote sensing images. The general ecosystem functioning encompasses three different phases. The first one, over the autumn and the winter, a biological dormancy period causes low CO2 emissions (ca. 1-5 µmol m-2 s-1), which coincides with the EVI and NDVI. The intermittent flooding taking place during this period is expected to cause CH4 emissions. Then, during the spring months (March-May), larger CO2 respiratory emissions take place during the daytime (> 5 µmol m-2 s-1) due to an increase in air temperature, which turn to neutral at the end of spring due to the start of photosynthesis by the rice. The third phase corresponds to the vegetation growth, when the net CO2 uptake increases gradually up to maximum CO2

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Economic Performance of Traditional and Modern Rice Varieties under Different Water Management Systems

    Directory of Open Access Journals (Sweden)

    Manel Ben Hassen

    2017-02-01

    Full Text Available Italian rice production is progressively threatened by water scarcity. Some strategies have been developed to reduce water use. Nevertheless, reducing water irrigation amounts may lower paddy rice production. This publication compares the productivity and the economic performances of traditional and modern rice varieties in northern Italy using two different water management systems. The objective of this analysis is to enhance Italian rice cultivation at the economic, environmental and agronomic levels. Some positive variations of water productivity and economic water productivity were observed for the two varieties when using a lower amount of irrigation water. However, actual production costs and most water supply fees are the same for all the irrigation methods. Furthermore, the study of agronomic traits shows that during the recent years, there were no significant differences or increases of yield among varieties. Consequently, to be adopted by farmers, the irrigation costs coupled with improved rice accessions need to be optimized.

  5. Chemical, Sensorial and Rheological Properties of a New Organic Rice Bran Beverage

    Directory of Open Access Journals (Sweden)

    Gerson Luis FACCIN

    2009-09-01

    Full Text Available Rice bran is a solid residue from rice polishing that is used in animal nutrition and rice oil production. Cultivation conditions with agro-toxics, lipids instability, and tendency for mycotoxin contamination restrict its application in human nutrition. Therefore, organic agriculture is an alternative to use the properties of rice bran. Rice bran beverage is a new cereal product from organic rice. This work presents the preliminary results of the chemical and rheological studies of a bath pasteurized rice bran beverage. Compared with integral defatted milk, soy extracts, and brown rice low-fat milk, the rice bran beverage studied in this work presents itself as an important source of minerals and unsaturated lipids. All essential amino acids were found in this product. Glutamic and aspartic acids were predominant. Bath pasteurization at boiling water temperature for 15 and 30 min was adequate for microbiological safety. Refrigeration storage for 20 days, evaluated by pH and acidity variations, was ideal for assessment of the beverage conservation time. The beverage viscosity was of the Newtonian standard behavior, and its viscosity during storage was not a good parameter to evaluate shelf life. Sensory preference tests showed positive perspectives for this new beverage.

  6. Effects of Low Light on Agronomic and Physiological Characteristics of Rice Including Grain Yield and Quality

    Directory of Open Access Journals (Sweden)

    Qi-hua LIU

    2014-09-01

    Full Text Available Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components (milling and appearance as well as cooking, eating and nutritional qualities under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.

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

    Science.gov (United States)

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

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

  8. Cultivating strategic thinking skills.

    Science.gov (United States)

    Shirey, Maria R

    2012-06-01

    This department highlights change management strategies that may be successful in strategically planning and executing organizational change initiatives. With the goal of presenting practical approaches helpful to nurse leaders advancing organizational change, content includes evidence-based projects, tools, and resources that mobilize and sustain organizational change initiatives. In this article, the author presents an overview of strategic leadership and offers approaches for cultivating strategic thinking skills.

  9. Cultivating an entrepreneurial mindset.

    Science.gov (United States)

    Matheson, Sandra A

    2013-01-01

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

  10. Cultivating Leaders of Indiana

    OpenAIRE

    yaryyeva, Annagul; Sdunzik, Jennifer

    2016-01-01

    "Cultivating Leaders of Indiana" was developed to establish connections between the Purdue student body and the Frankfort community. By engaging high school students in workshops that focused on local, national, and global identities, the goal of the project was to encourage students to appreciate their individuality and to motivate them to translate their skills into a global perspective.Moreover, workshops centering on themes such as culture, citizenship, media, and education were designed ...

  11. Improvement of traditional local rice varieties through induced mutations using nuclear techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pham Van Ro; Do Huu At [Cuu Long Delta Rice Research Institute (Viet Nam)

    2001-03-01

    'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

  12. Gene interaction at seed-awning loci in the genetic background of wild rice.

    Science.gov (United States)

    Ikemoto, Mai; Otsuka, Mitsuharu; Thanh, Pham Thien; Phan, Phuong Dang Thai; Ishikawa, Ryo; Ishii, Takashige

    2017-09-12

    Seed awning is one of the important traits for successful propagation in wild rice. During the domestication of rice by ancient humans, plants with awnless seeds may have been selected because long awns hindered collection and handling activities. To investigate domestication of awnless rice, QTL analysis for seed awning was first carried out using backcross recombinant inbred lines between Oryza sativa Nipponbare (recurrent parent) and O. rufipogon W630 (donor parent). Two strong QTLs were detected in the same regions as known major seed-awning loci, An-1 and RAE2. Subsequent causal mutation surveying and fine mapping confirmed that O. rufipogon W630 has functional alleles at both loci. The gene effects and interactions at these loci were examined using two backcross populations with reciprocal genetic backgrounds of O. sativa Nipponbare and O. rufipogon W630. As awn length in wild rice varied among seeds even in the same plant, awn length was measured based on spikelet position. In the genetic background of cultivated rice, the wild alleles at An-1 and RAE2 had awning effects, and plants having both wild homozygous alleles produced awns whose length was about 70% of those of the wild parent. On the other hand, in the genetic background of wild rice, the substitution of cultivated alleles at An-1 and RAE2 contributed little to awn length reduction. These results indicate that the domestication process of awnless seeds was complicated because many genes are involved in awn formation in wild rice.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Dissipation gradients of phenanthrene and pyrene in the Rice rhizosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Y.; Wu, S.C.; Yu, X.Z. [Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong (Hong Kong); Wong, M.H., E-mail: mhwong@hkbu.edu.h [Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong (Hong Kong); Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China)

    2010-08-15

    An experiment was conducted to reveal the effects of rice cultivation as well as polycyclic aromatic carbohydrates (PAHs) degrading bacterium (Acinetobacter sp.) on the dissipation gradients of two PAHs (PHE and PYR) in the rhizosphere. The results showed that the presence of rice root and bacteria significantly accelerated the dissipation rate of PHE and PYR. The root exudates contributed to the formation of dissipation gradients of PHE and PYR along the vertical direction of roots, with a higher dissipation rate in the rhizosphere and near rhizosphere zone than the soil far away the rhizosphere. - The formation of dissipation gradients of PAHs were attributed to the presence of rice root and the degrading bacteria in paddy soil.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Takahide eSasaya

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-13

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

  18. Monitoring and Management of Imidazolinone-Resistant Red Rice (Oryza sativa L., var. sylvatica in Clearfield® Italian Paddy Rice

    Directory of Open Access Journals (Sweden)

    Laura Scarabel

    2012-12-01

    Full Text Available The introduction in Italy of Clearfield® rice cultivars carrying imidazolinone-resistant traits provides an efficient option to control red rice, a conspecific weed of cultivated rice. However, despite the promulgation of specific guidelines for Clearfield® technology management, imazamox red rice survivors have been reported by farmers. Forty-two fields were monitored in 2010 and 2011 throughout the Piedmont and Lombardy regions and field cases were recorded of herbicides use and agronomic practices. Whole-plant sensitivity to imazamox was assessed and the resistance mechanism was determined by molecular analysis. Twenty-six red rice populations out of 42 were imazamox-resistant and plants of all the resistant populations possess a Ser to Asn substitution at locus 653 of the ALS gene determining the target-site resistance. Farmers frequently grow Clearfield® varieties for more than two consecutive years so increasing the selection pressure exerted by imazamox and favoring the evolution of resistant red rice. To maintain the sustainability of this new technology, a proper management based on crop rotation, utilization of certified seeds and strict control of red rice escapes has to be implemented. More generally, all stakeholders must increase their awareness that the selection pressure exerted by ALS inhibitors in rice cropping system should be reduced.

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Factors Affecting the Growth and Production of Milk-Clotting Enzyme by Amylomyces rouxii in Rice Liquid Medium

    Directory of Open Access Journals (Sweden)

    Pei-Jing Yu

    2005-01-01

    Full Text Available Amylomyces rouxii is one of the main fungi usually coexisting with yeasts in Chinese yeast ball, the starter of chiu-niang, a traditional Chinese fermented product from rice. In the present study, growth and production of milk-clotting enzyme (MCE in gelatinous rice liquid culture of A. rouxii as influenced by waxy (gelatinous rice content in the medium (5–20 %, temperature (25–40 °C, cultivation time (1–6 days, shaking speeds (0–150 rpm and metal ions (Na+, K+, Zn2+, Mg2+, Mn2+, Cu2+, Ca2+, Fe3+ and Al3+ were investigated. Results revealed that rice content in the medium, shaking speed, temperature and cultivation time all affected the mycelial propagation and the production of milk-clotting enzyme by A. rouxii in the rice liquid culture. The maximum milk-clotting enzyme activity of ca. 1.22 unit/mL of medium was observed in the 3-day static culture of test organism grown at 30 °C in the medium containing 20 % of gelatinous rice, while mycelial propagation increased with the increase of cultivation time and shaking speed. Furthermore, a significant increase (p<0.05 in the milk-clotting enzyme activity of ca. 1.90 unit/mL of medium, which was about 1.55-fold of the control, was observed when Al3+ was added to the rice liquid medium.

  1. Cultivation of oyster mushroom (Pleurotus ostreatus on oil palm residues

    Directory of Open Access Journals (Sweden)

    Tongwised, A.

    2001-11-01

    Full Text Available This study is aimed to use oil palm residues to cultivate the oyster mushroom, Pleurotus ostreatus, which is one of the most important mushrooms cultivated worldwide. Spawn was prepared on sorghum seeds and inoculated on substrate in plastic bags. Oil palm fronds were cut and used to grow Pleurotus ostreatus. The first fructification occurred 20 days after waterring. The biological efficiency reached at 28.6%. When sawdust of para rubber logs was added to the cut oil palm fronds at the rate of 1:1 (vol : vol., the biological efficiency reached at 39.3%.Supplementary material at the rate of 5% was also added into the combination of cut oil palm frond and sawdust. The result showed that rice bran, corn meal or oil palm-kernel meal give yields between 142.2-165.0 g/bag (B.E. = 42.8-49.6, which were not statistically different. Oil palm pericarp waste was also used as main substrate for P. ostreatus cultivation. The average yield obtained during 40 days havesting period was 112.6 g/bag (B.E. = 64.3%. Addition of sawdust or rice bran into pericarp waste decreased the yield of the basidiocarps. Palm-kernel meal at the rate of 5-20% was used as a supplement material. Addition of 20% palmkernel meal into sawdust supported higher yield. The biological efficiency reached 55.8%. From the above results, four formulae of the substrate were prepared. Treatment of oil palm pericarp waste + 3% rice bran + 3% corn meal + 0.75% Ca(OH2 supported higher yield of the basidiocarps. The average yield obtained from 950 g of substrate was 190.2 g during 60 days havesting (B.E. = 57.2%. Using 6% palm-kernel substitute 3% rice bran + 3% corn meal supported the same yield (B.E. = 56.2% Using sawdust as the main substrate, the yield achieved was less than that obtained with oil palm pericarp waste. The average yield from treatment of sawdust + 3% rice bran + 3% corn meal + 0.75% Ca (OH2 was 154.0 g/bag (B.E. = 46.3% while treatment of sawdust + 6% palm-kernel meal + 0

  2. Incorporation of whole, ancient grains into a modern Asian Indian diet to reduce the burden of chronic disease.

    Science.gov (United States)

    Dixit, Anjali A; Azar, Kristen Mj; Gardner, Christopher D; Palaniappan, Latha P

    2011-08-01

    Refined carbohydrates, such as white rice and white flour, are the mainstay of the modern Asian Indian diet, and may contribute to the rising incidence of type 2 diabetes and cardiovascular disease in this population. Prior to the 1950s, whole grains such as amaranth, barley, brown rice, millet, and sorghum were more commonly used in Asian Indian cooking. These grains and other non-Indian grains such as couscous, quinoa, and spelt are nutritionally advantageous and may be culturally acceptable carbohydrate substitutes for Asian Indians. This review focuses on practical recommendations for culturally sensitive carbohydrate modification in a modern Asian Indian diet to reduce type 2 diabetes and cardiovascular disease in this population. © 2011 International Life Sciences Institute.

  3. Incorporation of Whole, Ancient Grains into a Modern Asian Indian Diet: Practical Strategies to Reduce the Burden of Chronic Disease

    Science.gov (United States)

    Dixit, Anjali A.; Azar, Kristen M. J.; Gardner, Christopher D.; Palaniappan, Latha P.

    2011-01-01

    Refined carbohydrates, such as white rice and white flour, are the mainstay of the modern Asian Indian diet, and may contribute to the rising incidence of type 2 diabetes and cardiovascular disease in this population. Prior to the 1950s, whole grains such as amaranth, barley, brown rice, millet, and sorghum were more commonly used in Asian Indian cooking. These grains and other non-Indian grains such as couscous, quinoa, and spelt are nutritionally advantageous and may be culturally acceptable carbohydrate substitutes for Asian Indians. This review focuses on practical recommendations for culturally sensitive carbohydrate modification in a modern Asian Indian diet, in an effort to reduce type 2 diabetes and cardiovascular disease in this population. PMID:21790614

  4. Asian Art on Display

    DEFF Research Database (Denmark)

    Borggreen, Gunhild Ravn

    2010-01-01

    Med udgangspunkt i seminaret Visualising Asian Modernity diskuteres forholdet mellem antropologi og samtidskunst i lyset af hvorledes asiatisk kunst fremvises og formidles i vestlig og dansk sammenhæng....

  5. Profile: Asian Americans

    Science.gov (United States)

    ... and diabetes. Asian Americans also have a high prevalence of the following conditions and risk factors: chronic obstructive pulmonary disease, hepatitis B, HIV/AIDS, smoking, tuberculosis, and liver ...

  6. Central Asian Republic Info

    Data.gov (United States)

    US Agency for International Development — CAR Info is designed and managed by the Central Asian Republic Mission to fill in the knowledge and reporting gaps in existing agency systems for that Mission. It...

  7. The South Asian genome.

    Directory of Open Access Journals (Sweden)

    John C Chambers

    Full Text Available The genetic sequence variation of people from the Indian subcontinent who comprise one-quarter of the world's population, is not well described. We carried out whole genome sequencing of 168 South Asians, along with whole-exome sequencing of 147 South Asians to provide deeper characterisation of coding regions. We identify 12,962,155 autosomal sequence variants, including 2,946,861 new SNPs and 312,738 novel indels. This catalogue of SNPs and indels amongst South Asians provides the first comprehensive map of genetic variation in this major human population, and reveals evidence for selective pressures on genes involved in skin biology, metabolism, infection and immunity. Our results will accelerate the search for the genetic variants underlying susceptibility to disorders such as type-2 diabetes and cardiovascular disease which are highly prevalent amongst South Asians.

  8. Rice-eating pattern and the risk of metabolic syndrome especially waist circumference in Korean Genome and Epidemiology Study (KoGES).

    Science.gov (United States)

    Ahn, Younjhin; Park, Seon-Joo; Kwack, Hye-Kyoung; Kim, Mi Kyung; Ko, Kwang-Pil; Kim, Sung Soo

    2013-01-22

    Metabolic syndrome poses a serious health threat in Asian countries. Rice is a staple food in Korea, and carbohydrate intake is associated with the risk of MetS. We hypothesized that various rice-eating patterns in a carbohydrate-based diet would have different effects on the risk of MetS. Participants were 26,006 subjects enrolled in the Korean Genome and Epidemiology Study between 2004 and 2006. They were classified into four dietary patterns - white rice, rice with beans, rice with multi-grains, and mixed based on their food frequency questionnaire responses. We compared metabolic risk traits according to the rice-eating patterns. Nutrients consumption and the presence of MetS risk factors differed according to rice-eating patterns. In men odds ratio(OR) for central obesity was slightly elevated in mixed group(1.18). In women, the risk for central obesity and abnormal fasting glucose were lower in the rice with beans group (adjusted OR =0.79, 0.83 respectively) and central obesity in rice with multi-grains(adjusted OR=0.91) than the white rice group. In postmenopausal women, ORs for central obesity (0.78) and abnormal fasting glucose (0.75) in the rice with beans group and ORs for central obesity (0.83), abnormal HDL-cholesterol (0.87) and MetS(0.85) in the rice with multi-grains group was lower than those in white rice group. In premenopausal women, the risk for central obesity (OR=0.77) was reduced in the rice with beans group. The risk for MetS was lower in the rice with beans and rice with multi-grains groups compared with the white rice group, particularly in postmenopausal women.

  9. The Asian Face Lift

    OpenAIRE

    Bergeron, Léonard; Chen, Yu-Ray

    2009-01-01

    The face-lift procedure (rhytidectomy) is increasingly popular in Asia. There is extensive literature on different techniques in Western patients. Cultural and anthropomorphologic differences between Asian and Caucasians require the adaptation of current techniques to obtain a satisfactory outcome for both the patient and the surgeon. This article therefore attempts to define important differences between Asians and Caucasians in terms of signs of facial aging, perception of beauty, and surgi...

  10. Tibet as a Potential Domestication Center of Cultivated Barley of China

    Science.gov (United States)

    Ren, Xifeng; Nevo, Eviatar; Sun, Dongfa; Sun, Genlou

    2013-01-01

    The importance of wild barley from Qinghai-Tibet Plateau in the origin and domestication of cultivated barley has long been underestimated. Population-based phylogenetic analyses were performed to study the origin and genetic diversity of Chinese domesticated barley, and address the possibility that the Tibetan region in China was an independent center of barley domestication. Wild barley (Hordeum vulgare ssp. spontaneum) populations from Southwest Asia, Central Asia, and Tibet along with domesticated barley from China were analyzed using two nuclear genes. Our results showed that Tibetan wild barley distinctly diverged from Southwest Asian (Near East) wild barley, that Central Asian wild barley is related to Southwest Asian wild barley, and that Chinese domesticated barley shares the same haplotypes with Tibetan wild barley. Phylogenetic analysis showed a close relationship between Chinese domesticated barley and the Tibetan wild barley, suggesting that Tibetan wild barley was the ancestor of Chinese domesticated barley. Our results favor the polyphyletic origin for cultivated barley. PMID:23658764

  11. Potassium hydroxide pulping of rice straw in biorefinery initiatives.

    Science.gov (United States)

    Jahan, M Sarwar; Haris, Fahmida; Rahman, M Mostafizur; Samaddar, Purabi Rani; Sutradhar, Shrikanta

    2016-11-01

    Rice straw is supposed to be one of the most important lignocellulosic raw materials for pulp mill in Asian countries. The major problem in rice straw pulping is silica. The present research is focused on the separation of silica from the black liquor of rice straw pulping by potassium hydroxide (KOH) and pulp evaluation. Optimum KOH pulping conditions of rice straw were alkali charge 12% as NaOH, cooking temperature 150°C for 2h and material to liquor ratio, 1:6. At this condition pulp yield was 42.4% with kappa number 10.3. KOH pulp bleached to 85% brightness by D0EpD1 bleaching sequences with ClO2 consumption of 25kg/ton of pulp. Silica and lignin were separated from the black liquor of KOH pulping. The amount of recovered silica, lignin and hemicelluloses were 10.4%, 8.4% and 13.0%. The papermaking properties of KOH pulp from rice straw were slightly better than those of corresponding NaOH pulp. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. In Vivo Hypocholesterolemic Effect of MARDI Fermented Red Yeast Rice Water Extract in High Cholesterol Diet Fed Mice

    OpenAIRE

    Swee Keong Yeap; Boon Kee Beh; Joan Kong; Wan Yong Ho; Hamidah Mohd Yusof; Nurul Elyani Mohamad; Aminuddin bin Hussin; Indu Bala Jaganath; Noorjahan Banu Alitheen; Anisah Jamaluddin; Kamariah Long

    2014-01-01

    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of γ-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities w...

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

    Science.gov (United States)

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

    2014-03-01

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

  14. Evaluating Crossbred Red Rice Variants for Postprandial Glucometabolic Responses: A Comparison with Commercial Varieties

    Directory of Open Access Journals (Sweden)

    Chee-Hee Se

    2016-05-01

    Full Text Available Consumption of white rice predisposes some Asian populations to increased risk of type 2 diabetes. We compared the postprandial glucometabolic responses to three newly-developed crossbred red rice variants (UKMRC9, UKMRC10, UKMRC11 against three selected commercial rice types (Thai red, Basmati white, Jasmine white using 50-g carbohydrate equivalents provided to 12 normoglycaemic adults in a crossover design. Venous blood was drawn fasted and postprandially for three hours. Glycaemic (GI and insulin (II indices, incremental areas-under-the-curves for glucose and insulin (IAUCins, indices of insulin sensitivity and secretion, lactate and peptide hormones (motilin, neuropeptide-Y, orexin-A were analyzed. The lowest to highest trends for GI and II were similar i.e., UKMRC9 < Basmati < Thai red < UKMRC10 < UKMRC11 < Jasmine. Postprandial insulinaemia and IAUCins of only UKMRC9 were significantly the lowest compared to Jasmine. Crude protein and fiber content correlated negatively with the GI values of the test rice. Although peptide hormones were not associated with GI and II characteristics of test rice, early and late phases of prandial neuropeptide-Y changes were negatively correlated with postprandial insulinaemia. This study indicated that only UKMRC9 among the new rice crossbreeds could serve as an alternative cereal option to improve diet quality of Asians with its lowest glycaemic and insulinaemic burden.

  15. Migration, isolation and hybridization in island crop populations: the case of Madagascar rice.

    Science.gov (United States)

    Mather, Kristie A; Molina, Jeanmaire; Flowers, Jonathan M; Rubinstein, Samara; Rauh, Brad L; Lawton-Rauh, Amy; Caicedo, Ana L; McNally, Kenneth L; Purugganan, Michael D

    2010-11-01

    Understanding how crop species spread and are introduced to new areas provides insights into the nature of species range expansions. The domesticated species Oryza sativa or Asian rice is one of the key domesticated crop species in the world. The island of Madagascar off the coast of East Africa was one of the last major Old World areas of introduction of rice after the domestication of this crop species and before extensive historical global trade in this crop. Asian rice was introduced in Madagascar from India, the Malay Peninsula and Indonesia approximately 800-1400 years ago. Studies of domestication traits characteristic of the two independently domesticated Asian rice subspecies, indica and tropical japonica, suggest two major waves of migrations into Madagascar. A population genetic analysis of rice in Madagascar using sequence data from 53 gene fragments provided insights into the dynamics of island founder events during the expansion of a crop species' geographic range and introduction to novel agro-ecological environments. We observed a significant decrease in genetic diversity in rice from Madagascar when compared to those in Asia, likely the result of a bottleneck on the island. We also found a high frequency of a unique indica type in Madagascar that shows clear population differentiation from most of the sampled Asian landraces, as well as differential exchange of alleles between Asia and Madagascar populations of the tropical japonica subspecies. Finally, despite partial reproductive isolation between japonica and indica, there was evidence of indica/japonica recombination resulting from their hybridization on the island. © 2010 Blackwell Publishing Ltd.

  16. Cambodia Rice Sector Review

    OpenAIRE

    World Bank Group

    2015-01-01

    Cambodia’s rice harvests have been rising significantly since 2005, powered by improved and expanded irrigation and attractive farm gate prices. In 2010, the Cambodian government announced an export target of 1.0 million tons of milled rice by 2015. This analysis, which updates reports prepared in 2009 and 2011, seeks to identify short-term policy measures that can assist Cambodian exporte...

  17. The Evolutionary Basis of Naturally Diverse Rice Leaves Anatomy

    Science.gov (United States)

    Chatterjee, Jolly; Dionora, Jacqueline; Elmido-Mabilangan, Abigail; Wanchana, Samart; Thakur, Vivek; Bandyopadhyay, Anindya; Brar, Darshan S.; Quick, William Paul

    2016-01-01

    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. PMID:27792743

  18. Genealogy of the "Green Revolution" gene in rice.

    Science.gov (United States)

    Nagano, Hironori; Onishi, Kazumitsu; Ogasawara, Mitsuhiro; Horiuchi, Yuki; Sano, Yoshio

    2005-10-01

    During the "Green Revolution" of rice, high-yielding varieties (HYVs) were developed using a semi-dwarf gene (sd1 or OsGA20ox2). The presence or absence of the two mutant alleles (DGWG type in Dee-geo-woo-gen and JKK type in Jikkoku) were surveyed by PCR using 256 accessions of eight wild and two cultivate rice species. The DGWG allele was detected in a landrace (Oryza sativa) and two accessions of wild rice (O. rufipogon), all of which are from China, showing their limited distribution. Genealogical studies of the OsGA20ox2 gene showed that the 62 sequences of O. sativa and O. rufipogon included 20 distinct haplotypes, indicating that the species complex contained OsGA20ox2 genes from two different lineages. The silent site nucleotide diversities (pi and theta(w)) were extremely low in Japonica rice, suggesting a genetic bottleneck. The haplotype network showed that the DGWG and JKK alleles were derived in different lineages. The DGWG carrier (W1944) had unique polymorphisms in the surrounding region of the locus, suggesting that the DGWG allele has been preserved in the wild progenitor, rather than that the DGWG allele has been introgressed from HYVs to W1944. Although a semi-dwarfing plant is a weak competitor under saturated fields, the crossing experiment revealed that the DGWG variant might have been preserved as a hidden variation in the genetic background of wild rice, without expressing a short-stature.

  19. Cutaneous Mycoses among Rice Farmers in Anambra State, Nigeria

    Directory of Open Access Journals (Sweden)

    Chito Clare Ekwealor

    2013-01-01

    Full Text Available Rice grain is one of the world's most important food crops, and its cultivation is a major occupation in Anambra State, Nigeria. These rice farmers are exposed to various agents that predispose them to cutaneous mycoses. The aim of this work was to screen rice farmers for lesions suggestive of cutaneous mycoses and to isolate and identify fungal agents associated with the infection. This survey was carried out between November 2009 and June 2011 in Anambra State, Nigeria. Clinical samples collected from 201 farmers with lesions suggestive of cutaneous mycoses were processed and the organisms identified. Questionnaires were used to obtain other necessary data and were statistically analyzed. Of the 2,580 rice farmers screened, 201 (7.79% showed positive lesions. Organisms recovered included Microsporum audouinii, Microsporum ferrugineum, Trichophyton megnini, Trichophyton tonsurans, Trichophyton rubrum, Aspergillus terrus, Aspergillus candidus, Aspergillus scleriotorum, Aspergillus niger, Aspergillus flavus, Scopulariopsis sp., Chrysosporium sp., Eupenicillium javanicum, Fusarium sp., Penicillium aculeatum, and Penicillium pinophilum. At the end of this work, onychomycosis was observed to be the most prevalent with nondermatophyte molds now becoming very important agents of cutaneous mycoses among rice farmer.

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

    Science.gov (United States)

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

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

  1. 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.

  2. Gene, protein and network of male sterility in rice

    Directory of Open Access Journals (Sweden)

    Wang eKun

    2013-04-01

    Full Text Available Rice is one of the most important model crop plants whose heterosis has been well exploited in commercial hybrid seed production via a variety of types of male sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and proteins related to cytoplasmic male sterility, photoperiod sensitive male sterility, self-incompatibility and other types of microspores deterioration have been characterized through genetics or proteomics. Especially the latter, offers us a powerful and high throughput approach to discern the novel proteins involving in male-sterile pathways which may help us to breed artificial male-sterile system. This represents an alternative tool to meet the critical challenge of further development of hybrid rice. In this paper, we reviewed the recent developments in our understanding of male sterility in rice hybrid production across gene, protein and integrated network levels, and also, present a perspective on the engineering of male sterile lines for hybrid rice production.

  3. Environmental relations between inland rice culture and the Cooper and Wando River watersheds, South Carolina

    Science.gov (United States)

    Hayden R. Smith

    2016-01-01

    This study explains the geographical importance of the Cooper and Wando River watersheds, located east of Charleston (SC), in relation to inland rice cultivation during the colonial and antebellum periods. By focusing on the geological formation of this watershed, this paper will explain the connection between this plantation enterprise and the natural environment. The...

  4. Dissipation of clomazone, imazapyr and imazapic herbicides in paddy water under two rice flood management regimes

    Science.gov (United States)

    Pesticides are frequently detected in rivers, lakes and groundwater sources in regions where rice is cultivated in Brazil. The transport of these compounds to water sources is strongly related to the irrigation system adopted in paddy fields. However, information on the dissipation of clomazone, ima...

  5. Response of high yielding rice varieties to NaCl salinity in ...

    African Journals Online (AJOL)

    Salinity is one the biggest constraint to obtain crop potential yield throughout paddy fields in some part of the coastal line of rice cultivated area in Iran. In order to find resistant varieties and study the reaction of some newly released high yielding varieties to different levels of salinity of irrigation water an experiment was ...

  6. Genetic Control of a Transition from Black to Straw-White Seed Hull in Rice Domestication1[C][W][OA

    Science.gov (United States)

    Zhu, Bo-Feng; Si, Lizhen; Wang, Zixuan; Jingjie Zhu, Yan Zhou; Shangguan, Yingying; Lu, Danfeng; Fan, Danlin; Li, Canyang; Lin, Hongxuan; Qian, Qian; Sang, Tao; Zhou, Bo; Minobe, Yuzo; Han, Bin

    2011-01-01

    The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication. PMID:21263038

  7. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  8. 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

  9. Physical, chemical, and biological properties of soil under soybean cultivation and at an adjacent rainforest in Amazonia

    Science.gov (United States)

    T.P. Beldini; R.C. Oliveira Junior; Michael Keller; P.B. de Camargo; P.M. Crill; A. Damasceno da Silva; D. Bentes dos Santos; D. Rocha de Oliveira

    2015-01-01

    Land-use change in the Amazon basin has occurred at an accelerated pace during the last decade, and it is important that the effects induced by these changes on soil properties are better understood. This study investigated the chemical, physical, and biological properties of soil in a field under cultivation of soy and rice, and at an adjacent primary rain forest....

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

    Science.gov (United States)

    Josephs, Ingrid E.; Fuhrer, Urs

    1998-01-01

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

  11. Rice straw addition as sawdust substitution in oyster mushroom (Pleurotus ostreatus) planted media

    Science.gov (United States)

    Utami, Christine Pamardining; Susilawati, Puspita Ratna

    2017-08-01

    Oyster mushroom is favorite by the people because of the high nutrients. The oyster mushroom cultivation usually using sawdust. The availability of sawdust become difficult to find. It makes difficulties of mushroom cultivation. Rice straw as an agricultural waste can be used as planted media of oyster mushroom because they contain much nutrition needed to the mushroom growth. The aims of this research were to analysis the influence of rice straw addition in a baglog as planted media and to analysis the concentration of rice straw addition which can substitute sawdust in planted media of oyster mushroom. This research used 4 treatment of sawdust and rice straw ratio K = 75 % : 0 %, P1 = 60 % : 15 %, P2 = 40 % : 35 %, P3 = 15 % : 60 %. The same material composition of all baglog was bran 20%, chalk 5%, and water 70%. The parameters used in this research were wet weight, dry weight, moisture content and number of the mushroom fruit body. Data analysis was used ANOVA test with 1 factorial. The results of this research based on statistical analysis showed that there was no influence of rice straw addition in a planted media on the oyster mushroomgrowth. 15% : 60% was the concentrationof rice straw additionwhich can substitute the sawdust in planted media of oyster mushroom.

  12. Prediction of protein-protein interactions between fungus (Magnaporthe grisea) and rice (Oryza sativa L.).

    Science.gov (United States)

    Ma, Shiwei; Song, Qi; Tao, Huan; Harrison, Andrew; Wang, Shaobo; Liu, Wei; Lin, Shoukai; Zhang, Ziding; Ai, Yufang; He, Huaqin

    2017-10-11

    Rice blast disease caused by the fungus Magnaporthe grisea (M. grisea) is one of the most serious diseases for the cultivated rice Oryza sativa (O. sativa). A key factor causing rice blast disease and defense might be protein-protein interactions (PPIs) between rice and fungus. In this research, we have developed a computational pipeline to predict PPIs between blast fungus and rice. After cross-prediction by interolog-based and domain-based method, we achieved 532 potential PPIs between 27 fungus proteins and 236 rice proteins. Accuracy of jackknife test, 10-fold cross-validation test and independent test for these PPIs were 90.43, 93.85 and 84.67%, respectively, by using support vector machine classification method. Meanwhile, the pathogenic genes of blast fungus were enriched in the predicted PPIs network when compared with 1000 random interaction networks. The rice regulatory network was downloaded and divided into 228 subnetworks with over six nodes, and the top seven subnetworks affected by blast fungus through PPIs were investigated. The results indicated that 34 upregulated and 12 downregulated master regulators in rice interacting with the fungus proteins in response to the infection of blast fungus. The common master regulators in rice in response to the infection of M. grisea, Xanthomonas oryzae pv.oryzae and rice stripe virus were analyzed. The ubiquitin proteasome pathway was the common pathway in rice regulated by these three pathogens, while apoptosis signaling pathway was induced by fungus and bacteria. In summary, the results in this article provide insight into the process of blast fungus infection. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Starting from grape cultivation.

    Science.gov (United States)

    Yoshida, A

    1992-06-01

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

  14. An alternative treatment of hyperlipidemia with red yeast rice: a case report.

    Science.gov (United States)

    Lin, James S

    2010-01-08

    Hyperlipidemia is prevalent and is highly associated with coronary heart disease. Some patients are reluctant or opt not to take lipid-lowering prescription medications for fear of adverse drug reactions. There are currently few well-designed randomized controlled trials showing the possibility of reducing cholesterol using red yeast rice. Meanwhile, adverse effects have also been reported. A 64-year-old Asian man was diagnosed with hyperlipidemia despite a healthy lifestyle. In addition to diet changes, the patient used red yeast rice and succeeded in lowering his level of serum lipids. Based on this case and a review of current literature, in addition to therapeutic lifestyle change, red yeast rice may be a useful alternative treatment for primary hyperlipidemia in patients with low cardiac risk and who refuse to take any lipid-lowering prescription medication or who maybe be statin intolerant.However, primary care physicians must be aware of the potential side effects of taking red yeast rice.

  15. Plasticity of Tiller Dynamics in Wild Rice Oryza rufipogon Griff.: A Strategy for Resilience in Suboptimal Environments

    Directory of Open Access Journals (Sweden)

    Pravat K. Mohapatra

    2011-01-01

    Full Text Available Rice cultivation in tropical Asia is susceptible to drought and flood and the need is high for stress resistant genes. Wild rice Oryza rufipogon Griff., grows in close sympatric association with cultivated rice in various habitats across the globe and possesses traits for survival under challenging environments. The species adapts according to the level of soil moisture available and modifies phenology, biomass production and grain yield. Variation in tiller dynamics of the species between contrasting environments gives an estimate of the adaptation. The species possesses AA genome, which permits genetic compatibility for cross breeding with cultivated rice. Utility of the species as possible repository of stress resistant genes is evaluated in this review by examining variation in assimilate partitioning between different classes of tillers of ecotypes growing across a gradation of habitats against background knowledge available for cultivated rice. Models have been constructed to explain mechanisms of tillering and tiller dynamics, and reveal the genotypic permissibility for resilience in sub-optimal environments. It is concluded that environmentally cued alteration in assimilate production and partitioning mask genetic potential for tiller production and survival. Tiller number in excess of resource capacity is corrected by senescence of late-tillers possibly through an ethylene-mediated signal.

  16. Comparison between rice husk ash grown in different regions for stabilizing fly ash from a solid waste incinerator.

    Science.gov (United States)

    Benassi, L; Bosio, A; Dalipi, R; Borgese, L; Rodella, N; Pasquali, M; Depero, L E; Bergese, P; Bontempi, E

    2015-08-15

    The Stabilization of heavy metals from municipal solid waste incineration (MSWI) fly ash by rice husk ash (RHA) is under intense study as an effective strategy to recover and reuse industrial and agricultural waste together. We compare the metal entrapment performances of RHA from different Asian rice sources – namely from Japonica rice grown in Italy and Indica rice grown in India – Physicochemical and morphological characterization of the final stabilized material show that the same thermal treatment may result in marked structural differences in the silica contained in the two RHA. Remarkably, one of them displays a crystalline silica content, although obtained by a thermal treatment below 800 °C. We also find that the presence of an alkali metal ion (potassium) in the rice husk plays a crucial role in the attainment of the final silica phase. These physicochemical differences are mirrored by different stabilization yields by the two RHA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Concentration of some heavy metals in rice types available in Shiraz market and human health risk assessment.

    Science.gov (United States)

    Naseri, Mahmood; Vazirzadeh, Arya; Kazemi, Robabeh; Zaheri, Farnaz

    2015-05-15

    This investigation was conducted to survey the levels of some heavy metals such as cadmium, lead, chromium, nickel and cobalt in domestic cultivated and imported rice sold on the Shiraz - Iran markets. The potential human health risk assessment was conducted by considering estimated weekly intake (EWI) of toxic metals from eating rice and compared calculated values with provisional tolerable weekly intake (PTWI). The mean values for lead and cadmium in domestic cultivated and imported rice were considerably higher than allowable limits set by FAO/WHO. In combination of recent rice consumption data, the estimated weekly intakes of toxic element were calculated for Iranian population. EWI for cadmium, nickel, chromium through imported and domestic cultivated rice consumption was lower than the PTWI. The EWI for lead were considerably higher than other measured toxic metals. The highest mean level of EWI for lead was observed in some imported rice samples (25.76 μg/kg body weight). Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Mental Health and Asian Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Asian American > Mental Health Mental Health and Asian Americans Suicide was the 9th leading ... Americans is half that of the White population. MENTAL HEALTH STATUS Serious psychological distress among adults 18 years ...

  19. Hybrid origins of cultivated potatoes

    Science.gov (United States)

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

  20. "Logistic analysis of algae cultivation"

    NARCIS (Netherlands)

    Slegers, P.M.; Leduc, S.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2015-01-01

    Energy requirements for resource transport of algae cultivation are unknown. This work describes the quantitative analysis of energy requirements for water and CO2 transport. Algae cultivation models were combined with the quantitative logistic decision model ‘BeWhere’ for the regions Benelux

  1. Adapting rice production to climate change for sustainable blue water consumption: an economic and virtual water analysis

    Science.gov (United States)

    Darzi-Naftchali, Abdullah; Karandish, Fatemeh

    2017-12-01

    Sustainable utilization of blue water resources under climate change is of great significance especially for producing high water-consuming crops in water-scarce regions. Based on the virtual water concept, we carried out a comprehensive field-modeling research to find the optimal agricultural practices regarding rice blue water consumption under prospective climate change. The DSSAT-CERES-Rice model was used in combination with 20 GCMs under three Representative Concentration Pathways of low (RCP2.6), intermediate (RCP4.6), and very high (RCP8.5) greenhouse concentrations to predict rice yield and water requirement and related virtual water and economic return for the base and future periods. The crop model was calibrated and validated based on the 2-year field data obtained from consolidated paddy fields of the Sari Agricultural Sciences and Natural Resources University during 2011 and 2012 rice cropping cycles. Climate change imposes an increase of 0.02-0.04 °C in air temperature which consequently shifts rice growing seasons to winter season, and shorten the length of rice physiological maturity period by 2-15 days. While rice virtual water reduces by 0.1-20.6% during 2011-2070, reduced rice yield by 3.8-22.6% over the late twenty-first century results in a considerable increase in rice virtual water. By increasing the contribution of green water in supplying crop water requirement, earlier cropping could diminish blue water consumption for rice production in the region while cultivation postponement increases irrigation water requirement by 2-195 m3 ha-1. Forty days delay in rice cultivation in future will result in 29.9-40.6% yield reduction and 43.9-60% increase in rice virtual water under different scenarios. Earlier cropping during the 2011-2040 and 2041-2070 periods would increase water productivity, unit value of water, and economic value of blue water compared to the base period. Based on the results, management of rice cultivation calendar is a

  2. Rice is the seed of the monocot plants Oryza sativa (Asian rice) or ...

    African Journals Online (AJOL)

    BIOTECH

    2013-10-16

    tests. Biometrics 11:1-. 42. FAOSTAT (2001). FAO Statistical Databases. Available online at http://apps.fao.org/. Accessed 2 May 2001. Ghanti SK, Sujata KG, Rao S, Udayakumar M, Kavi Kishore PB (2009). Role of enzymes and ...

  3. Life cycle GHG evaluation of organic rice production in northern Thailand.

    Science.gov (United States)

    Yodkhum, Sanwasan; Gheewala, Shabbir H; Sampattagul, Sate

    2017-07-01

    Greenhouse gas (GHG) emission is one of the serious international environmental issues that can lead to severe damages such as climate change, sea level rise, emerging disease and many other impacts. Rice cultivation is associated with emissions of potent GHGs such as methane and nitrous oxide. Thai rice has been massively exported worldwide however the markets are becoming more competitive than ever since the green market has been hugely promoted. In order to maintain the same level or enhance of competitiveness, Thai rice needs to be considered for environmentally conscious products to meet the international environmental standards. Therefore, it is necessary to evaluate the greenhouse gas emissions throughout the life cycle of rice production in order to identify the major emission sources and possible reduction strategies. In this research, the rice variety considered is Khao Dawk Mali 105 (KDML 105) cultivated by organic practices. The data sources were Don-Chiang Organic Agricultural Cooperative (DCOAC), Mae-teang district, Chiang Mai province, Thailand and the Office of Agricultural Economics (OAE) of Thailand with onsite records and interviews of farmers in 2013. The GHG emissions were calculated from cradle-to-farm by using the Life Cycle Assessment (LCA) approach and the 2006 IPCC Guideline for National Greenhouse Gas Inventories. The functional unit is defined as 1 kg of paddy rice at farm gate. Results showed that the total GHG emissions of organic rice production were 0.58 kg CO 2 -eq per kg of paddy rice. The major source of GHG emission was from the field emissions accounting for 0.48 kg CO 2 -eq per kg of paddy rice, about 83% of total, followed by land preparation, harvesting and other stages (planting, cultivation and transport of raw materials) were 9, 5 and 3% of total, respectively. The comparative results clearly showed that the GHG emissions of organic paddy rice were considerably lower than conventional rice production due to the

  4. Crop and varietal diversification of rainfed rice based cropping systems for higher productivity and profitability in Eastern India.

    Science.gov (United States)

    Lal, B; Gautam, Priyanka; Panda, B B; Raja, R; Singh, Teekam; Tripathi, R; Shahid, M; Nayak, A K

    2017-01-01

    Rice-rice system and rice fallows are no longer productive in Southeast Asia. Crop and varietal diversification of the rice based cropping systems may improve the productivity and profitability of the systems. Diversification is also a viable option to mitigate the risk of climate change. In Eastern India, farmers cultivate rice during rainy season (June-September) and land leftovers fallow after rice harvest in the post-rainy season (November-May) due to lack of sufficient rainfall or irrigation amenities. However, in lowland areas, sufficient residual soil moistures are available in rice fallow in the post-rainy season (November-March), which can be utilized for raising second crops in the region. Implementation of suitable crop/varietal diversification is thus very much vital to achieve this objective. To assess the yield performance of rice varieties under timely and late sown conditions and to evaluate the performance of dry season crops following them, three different duration rice cultivars were transplanted in July and August. In dry season several non-rice crops were sown in rice fallow to constitute a cropping system. The results revealed that tiller occurrence, biomass accumulation, dry matter remobilization, crop growth rate, and ultimately yield were significantly decreased under late transplanting. On an average, around 30% yield reduction obtained under late sowing may be due to low temperature stress and high rainfall at reproductive stages of the crop. Dry season crops following short duration rice cultivars performed better in terms of grain yield. In the dry season, toria was profitable when sown earlier and if sowing was delayed greengram was suitable. Highest system productivity and profitability under timely sown rice may be due to higher dry matter remobilization from source to sink. A significant correlation was observed between biomass production and grain yield. We infer that late transplanting decrease the tiller occurrence and assimilate

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

    Science.gov (United States)

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

    2014-12-01

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

  6. Decreased use of pesticides for increased yields of rice and fish-options for sustainable food production in the Mekong Delta.

    Science.gov (United States)

    Berg, Håkan; Tam, Nguyen Thanh

    2018-04-01

    This study assesses the use of pesticides and the attitude to pest management strategies among rice and rice-fish farmers in the Can Tho and Tien Giang provinces in Vietnam. Interviews were made with 80 farmers. The farmers were divided in to farmers cultivating only rice with a high use (RHP) and low use (RLP) of pesticides, and farmers cultivating rice and fish with a high use (RFHP) and low use (RFLP) of pesticides. 80% of the HP farmers relied mainly on pesticides to control pests, while >80% of the LP farmers also applied IPM strategies. Insecticides were the most commonly used pesticides. 85% of all farmers experienced health effects from using pesticides. 80% of the farmers felt that the yield of fish had decreased over the last three years, and that this mainly was caused by pesticides. The RFHP farmers had lower fish survival and fish yields as compared to the RFLP farmers. The RFHP farmers also had significant lower rice yields than the RFLP farmers, and there were significant correlations between both decreased fish yields and rice yields with increased use of pesticides among rice-fish farmers. Increased rice yields were positively correlated with increased fish survival, indicating the synergistic effects between rice and fish production. Overall, the RFLP farmers had the highest income of the four farmers´ groups, while RFHP farmers had the lowest income. This shows that rice-fish farming provides a competitive and sustainable alternative to intensive rice-farming, but only if the farmer restricts the use of pesticides. This would not only help to reduce the production costs, but also to decrease environmental and health effects, and it is proposed that rice-fish farming with a low use of pesticides provides an attractive alternative to rice-monocropping for a sustainable and diversified food production in the Mekong Delta. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Scrolling and Strolling, Asian Style

    Science.gov (United States)

    Sterling, Joan

    2012-01-01

    In this article, the author describes a lesson on Asian cultures. Asian cultures demonstrate respect for nature through their art. Students learned how to use Asian brush techniques and designs to create scrolls. They also learned how to write Haiku, a three-line form of poetry that uses a pattern of syllables.

  8. Genetic diversity of high performance cultivars of upland and irrigated Brazilian rice.

    Science.gov (United States)

    Coelho, G R C; Brondani, C; Hoffmann, L V; Valdisser, P A M R; Borba, T C O; Mendonça, J A; Rodrigues, L A; de Menezes, I P P

    2017-09-21

    The objective of this study was to analyze the diversity and discrimination of high-performance Brazilian rice cultivars using microsatellite markers. Twenty-nine rice cultivars belonging to EMBRAPA Arroz e Feijão germplasm bank in Brazil were genotyped by 24 SSR markers to establish their structure and genetic discrimination. It was demonstrated that the analyzed germplasm of rice presents an expressive and significant genetic diversity with low heterogeneity among the cultivars. All 29 cultivars were differentiated genetically, and were organized into two groups related to their upland and irrigated cultivation systems. These groups showed a high genetic differentiation, with greater diversity within the group that includes the cultivars for irrigated system. The genotyping data of these cultivars, with the morphological e phenotypical data, are valuable information to be used by rice breeding programs to develop new improved cultivars.

  9. Deep RNA sequencing at single base-pair resolution reveals high complexity of the rice transcriptome

    DEFF Research Database (Denmark)

    Zhang, Guojie; Guo, Guangwu; Hu, Xueda

    2010-01-01

    Understanding the dynamics of eukaryotic transcriptome is essential for studying the complexity of transcriptional regulation and its impact on phenotype. However, comprehensive studies of transcriptomes at single base resolution are rare, even for modern organisms, and lacking for rice. Here, we...... present the first transcriptome atlas for eight organs of cultivated rice. Using high-throughput paired-end RNA-seq, we unambiguously detected transcripts expressing at an extremely low level, as well as a substantial number of novel transcripts, exons, and untranslated regions. An analysis of alternative...... splicing in the rice transcriptome revealed that alternative cis-splicing occurred in approximately 33% of all rice genes. This is far more than previously reported. In addition, we also identified 234 putative chimeric transcripts that seem to be produced by trans-splicing, indicating that transcript...

  10. Asian American Health

    Science.gov (United States)

    Every racial or ethnic group has specific health concerns. Differences in the health of groups can result from Genetics Environmental factors Access to care Cultural factors On this page, you'll find links to health issues that affect Asian Americans.

  11. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds,

  12. HIV Among Asians

    Science.gov (United States)

    ... Prevention VIH En Español Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... Email Updates on HIV Syndicated Content Website Feedback HIV Among Asians in the United States Format: Select ...

  13. Malaysian Cinema, Asian Film

    NARCIS (Netherlands)

    Heide, van der William

    2002-01-01

    This title series departs from traditional studies of national cinema by accentuating the intercultural and intertextual links between Malaysian films and Asian (as well as European and American) film practices. Using cross-cultural analysis, the author characterizes Malaysia as a pluralist society

  14. QTL map meets population genomics: an application to rice.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Fawcett

    Full Text Available Genes involved in the transition from wild to cultivated crop species should be of great agronomic importance. Population genomic approaches utilizing genome resequencing data have been recently applied for this purpose, although it only reports a large list of candidate genes with no biological information. Here, by resequencing more than 30 genomes altogether of wild rice Oryza rufipogon and cultivated rice O. sativa, we identified a number of regions with clear footprints of selection during the domestication process. We then focused on identifying candidate domestication genes in these regions by utilizing the wealth of QTL information in rice. We were able to identify a number of interesting candidates such as transcription factors that should control key domestication traits such as shattering, awn length, and seed dormancy. Other candidates include those that might have been related to the improvement of grain quality and those that might have been involved in the local adaptation to dry conditions and colder environments. Our study shows that population genomic approaches and QTL mapping information can be used together to identify genes that might be of agronomic importance.

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

    Science.gov (United States)

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

    2015-04-01

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

  16. Use of the p-SINE1-r2 in inferring evolutionary relationships of Thai rice varieties with AA genome

    Directory of Open Access Journals (Sweden)

    Preecha Prathepha

    2006-01-01

    Full Text Available In a previous study we described the prevalence and distribution in Thailand of the retroposon p- SINE1-r2, in the intron 10 of the waxy gene in cultivated and wild rice with the AA genome. In this study, additional varieties of rice were collected and sequencing was used to further characterize p-SINE1-r2. It was found that the length of the p-SINE1-r2 nucleotide sequences was about 125 bp, flanked by identical direct repeats of a 14 bp sequence. These sequences were compared and found to be similar to the sequences of p- SINE1-r2 found in Nipponbare, a rice strain discussed in a separate study. However, when compared the 48 DNA sequences identified in this study, much dissimilarity was found within the nucleotide sequences of p- SINE1-r2, in the form of base substitution mutations. Phylogenetic relationships inferred from the nucleotide sequences of these elements in cultivated rice (O. sativa and wild rice (O. nivara. It was found that rice accessions collected from the same geographical distribution have been placed in the same clade. The phylogenetic tree supports the origin and distribution of these rice strains.

  17. Detection and diagnosis of rice-infecting viruses

    Directory of Open Access Journals (Sweden)

    Tamaki Uehara Ichiki

    2013-10-01

    Full Text Available Rice-infecting viruses have caused serious damage to rice production in Asian, American, and African countries, where about 30 rice viruses and diseases have been reported. To control these diseases, developing accurate, quick methods to detect and diagnose the viruses in the host plants and any insect vectors of the viruses is very important. Based on an antigen–antibody reaction, serological methods such as latex agglutination reaction (LAR and enzyme-linked immunosorbent assay (ELISA have advanced to detect viral particles or major proteins derived from viruses. They aid in forecasting disease and surveying disease spread and are widely used for virus detection at plant protection stations and research laboratories. From the early 2000s, based on sequence information for the target virus, several other methods such as reverse transcription-polymerase chain reaction (RT-PCR and reverse transcription- loop-mediated isothermal amplification (RT-LAMP have been developed that are sensitive, rapid, and able to differentiate closely related viruses. Recent techniques such as real-time RT-PCR can be used to quantify the pathogen in target samples and monitor population dynamics of a virus, and metagenomic analyses using next-generation sequencing and microarrays show potential for use in the diagnosis of rice diseases.

  18. Competitive and Allelopathic Effects of Wild Rice Accessions (Oryza longistaminata) at Different Growth Stages.

    Science.gov (United States)

    Shen, Shicai; Xu, Gaofeng; Clements, David Roy; Jin, Guimei; Zhang, Fudou; Tao, Dayun; Xu, Peng

    2016-01-01

    The competitive and allelopathic effects of wild rice (Oryza longistaminata) accessions on barnyard grass at different growth stages determined by days after sowing (0, 30, 60 and 90 days) were studied in greenhouse pot experiments. Wild rice accession RL159 exhibited the greatest height and tillering. The weed suppression rates of wild rice accessions OL and F1 on barnyard grass were significantly higher than for other rice accessions, with the lowest being O. sativa cultivar RD23. The highest suppression rates of OL and F1 were 80.23 and 73.96% at barnyard grass growth stages of 90 days and 60 days. At a 90 growth stage, wild rice accessions RL159 and RL169 caused 61.33 and 54.51% inhibition in barnyard grass growth, respectively. Under the same conditions, the competitive inhibition rates of OL, F1, RL159, RL169 and RL219 against barnyard grass were markedly lower than their weed suppressive effects, but were relatively similar for RD23. The allelopathic inhibition of OL and F1 on barnyard grass was significantly higher than other rice accessions. The highest allelopathic rates of OL and F1 were 60.61 and 56.87% at the 0 day growth stage. It is concluded that wild rice accessions OL and F1 exhibited the highest allelopathic activity along with moderate competitive ability against barnyard grass; wild rice accession RL159 had the highest competitive ability and moderate allelopathic activity on barnyard grass. Thus, the three wild rice accessions OL, F1 and RL159 could be used as ideal breeding materials for cultivated rice improvement.

  19. Good manufacturing practices production of a purification-free oral cholera vaccine expressed in transgenic rice plants.

    Science.gov (United States)

    Kashima, Koji; Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Suzuki, Yuji; Minakawa, Satomi; Takeyama, Natsumi; Fukuyama, Yoshiko; Azegami, Tatsuhiko; Tanimoto, Takeshi; Kuroda, Masaharu; Tamura, Minoru; Gomi, Yasuyuki; Kiyono, Hiroshi

    2016-03-01

    The first Good Manufacturing Practices production of a purification-free rice-based oral cholera vaccine (MucoRice-CTB) from transgenic plants in a closed cultivation system yielded a product meeting regulatory requirements. Despite our knowledge of their advantages, plant-based vaccines remain unavailable for human use in both developing and industrialized countries. A leading, practical obstacle to their widespread use is producing plant-based vaccines that meet governmental regulatory requirements. Here, we report the first production according to current Good Manufacturing Practices of a rice-based vaccine, the cholera vaccine MucoRice-CTB, at an academic institution. To this end, we established specifications and methods for the master seed bank (MSB) of MucoRice-CTB, which was previously generated as a selection-marker-free line, evaluated its propagation, and given that the stored seeds must be renewed periodically. The production of MucoRice-CTB incorporated a closed hydroponic system for cultivating the transgenic plants, to minimize variations in expression and quality during vaccine manufacture. This type of molecular farming factory can be operated year-round, generating three harvests annually, and is cost- and production-effective. Rice was polished to a ratio of 95 % and then powdered to produce the MucoRice-CTB drug substance, and the identity, potency, and safety of the MucoRice-CTB product met pre-established release requirements. The formulation of MucoRice-CTB made by fine-powdering of drug substance and packaged in an aluminum pouch is being evaluated in a physician-initiated phase I study.

  20. Emission of Methyl halides from Japanese rice paddy fields.

    Science.gov (United States)

    Komori, D.; Sudo, S.; Akiyama, H.; Nishimura, S.; Yagi, K.; Hayashi, K.; Tanaka, Y.; Yamada, K.; Toyoda, S.; Koba, K.; Yoshida, N.

    2005-12-01

    Rice paddy field is one of emission source of methyl halide (MeX: X = Cl, Br, I) which are concerned about stratospheric ozone depletion and enhanced aerosol formation. Although significant amounts of MeX which are estimated to be emitted from rice paddies affect to regional and global atmospheric environment, understandings and recent estimations of production and consumption mechanisms of MeX have large uncertainty with depending on environmental conditions. In this study, new flux data sets of MeX emissions from Japanese rice paddy fields were reported. The fluxes of MeX were compared with environmental data sets which included meteorological parameters (ambient air temperature, ambient MeX concentrations, humidity, solar irradiance), soil parameters (soil temperature, pH, redox potential, soil water contents) to understand the emission mechanisms of MeX. Gas fluxes of C2H4 were also measured, which indicate rice plants growth and ageing. Observations of MeX flux were conducted with using automated closed chamber sampling system in Tsukuba, Japan, during a cultivation season of rice from May 2005 to September 2005. Rice plants were cultivated under intermittent irrigation. Soil gases were collected manually by using evacuated 1L stainless canisters once a week and every 4 hours in certain day during this period. Other environmental parameters were automatically obtained every 10 minutes. Seasonal variation of gas emissions of C2H4 were observed in maximum tillering phase and heading phase. In addition, clearly diurnal flux trends of C2H4 depending on solar irradiance were observed. These results suggested rice plant was remarkably growing in these phase. Similarly, large amounts of gas emissions of MeBr and MeI were observed in the same phase. Diurnal flux trends of MeBr and MeI were associated with solar irradiance. Results were generally consistent with previous reports (Redeker et al., 2000). On the other hand, MeCl flux was increased in later periods than

  1. Reconstructing Past Humidity Conditions Using Rice (Oryza sativa L.) Archive

    Science.gov (United States)

    Kaushal, Ritika; Ghosh, Prosenjit; Pokharia, Anil K.

    2017-04-01

    Variation of the Indian Summer Monsoon (ISM) in the perspective of climate change is a subject of concern given its pivotal role in sustaining the food and economic security of the Indian subcontinent. In this context, reconstruction of variation in moisture conditions (relative humidity (RH) and rainfall) associated with ISM has been carried out using tree ring archives located primarily over the Tibetan plateau [1,2]. However, limited studies have documented past variation of monsoonal RH over the main Indian landmass [3]. Here we present the potential of rice, the staple food of many ancient civilisations in Asia, to infer atmospheric moisture conditions prevalent over north-western India during 4,600 - 3500 years BP. Since rainfall associated with ISM is a crucial factor which governs rice productivity over Indian subcontinent, the rice crop is cultivated primarily during the ISM season. The sensitivity of oxygen and carbon isotope composition in the organic matter of rice and other plants (δ18OOM,δ13COM) to RH has been studied [4,5]. Thus, the present study uses stable isotope technique to decipher paleo-RH conditions using rice grains retrieved from archaeological sites belonging to the Mature Harappan phase and Chalcolithic period. The archaeo-samples were subjected to SEM/EDAX analysis to identify the morphology and elemental composition, followed by analysis for both δ18OOMgnd δ13COMafter treatment for carbonateremoval. The results obtained were compared with the observations of δ18OOM and δ13COMmeasured on modern day rice grains sampled across twenty three sites across India which experienced RH ranging from 67% to 89% (Kaushal and Ghosh (under review)). The study showed that decrease in RH was manifested as significant increase in δ18OOMvalues together with increase in the crop's intrinsic water use efficiency, as calculated from δ13COM. Based on this comparison; we inferred that the regional climate during the cultivation of the archaeo-rice

  2. Screening of Cultivatable Indigenous Fungi which Responsible for Decomposing of Rice Straw

    Directory of Open Access Journals (Sweden)

    Maryati

    2012-01-01

    Full Text Available The experiment was conducted to screen potentials indigenous fungi for rapid decomposing of rice straw. Sevenisolates of dominant fungi were isolated from the burying rice straw on the 2.5 cm soil depth after 30 days incubationon the paddy fields. Five dominant isolates were tested for their potential to decompose rice straw by assessingtheir value of decreasing C/N ratio and dry weight of rice straw. Fungal inoculums treatments were arranged in aCompletely Randomized Design with four replications. The results showed that the dominant cultivable fungi thatisolated from decomposed rice straw were Trichoderma sp., Fusarium sp., Mucor sp., Aspergillus sp., and Penicilliumsp. Among the tested fungi, Trichoderma sp. had the biggest ability to decompose rice straw compared to othersindigenous fungi. The C/N ratio was reduced to 39.47 from an initial value of 73.33 of control treatment in 10 days ofbiodegradation process in laboratory scale, thus showing the potential of indigenous Trichoderma sp. for use inlarge-scale composting of rice straw.

  3. Production of beta-carotene-enriched rice bran using solid-state fermentation of Rhodotorula glutinis.

    Science.gov (United States)

    Roadjanakamolson, M; Suntornsuk, W

    2010-03-01

    This work was aimed at utilizing rice bran as a substrate for beta-carotene production by Rhodotorula glutinis DM 28 under optimized conditions of solid-state fermentation. The biomass and beta-carotene content of Rhodotorula glutinis DM 28 grown on rice bran as a sole substrate under solid-state fermentation were 54 g/kg rice bran and 1.65 mg/kg rice bran, respectively. Its biomass and beta-carotene content, however, could be improved by 60% and 30%, respectively, using the Central Composite Design for the optimization of its cultivation conditions. The optimized conditions obtained were a pH of 5, a moisture content of 70% (w/w), and a carbon-to-nitrogen ratio of 4. Under these conditions, rice bran containing R. glutinis DM 28 had nutritional values of beta-carotene, protein, and fat higher than those of rice bran alone. Yeast-grown rice bran could be suitable, therefore, to use as a beta-carotene-enriched supplement in animal feeds.

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

    Science.gov (United States)

    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.

  5. Comparison of cadmium concentration and its weekly intake in imported and Iranian rice

    Directory of Open Access Journals (Sweden)

    M Cheraghi

    2015-08-01

    Full Text Available The aim of this study was to compare the concentration of Cadmium (Cd and its weekly intake among imported rice and the rice samples cultivated in Isfahan and Borojerd in 2011. For this reason, a total of 30 Indian imported rice samples together with 5 Iranian rice specimens were obtained from Hamedan and Tehran retails. The samples were subjected to acid digestion and afterwards the Cd concentrations were determined using ICP-OES. According to the results the mean ± SD values of Cd concentrations in imported and Iranian rice samples were determined as 107.60 ± 19.54 and 44.760 ± 12.55 µg/kg dry weight, respectively. Moreover, comparison of the mean concentrations of Cd in recent study with FAO/WHO permissible limits revealed that the Cd concentrations were below the approved limit. Data suggested that weekly intake of Cd through the consumption of imported and Iranian rice samples was 2.07 and 0.86 µg/kg body weight, respectively which was below the WHO/FAO limit. Based on the results of this study, both imported and Iranian rice do not pose a Cd-related health problem for the consumers. However, long-term accumulation of Cd in critical tissues could have health consequences.

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

    Science.gov (United States)

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

    2017-01-01

    Abstract 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. PMID:28323300

  7. Genomic diversity and introgression in O. sativa reveal the impact of domestication and breeding on the rice genome

    Science.gov (United States)

    The domestication of Asian rice (Oryza sativa) was a complex process and substantial ambiguity remains regarding the timing, number, and locations of domestication events. Deep genetic divergence between the two main varietal groups (Indica and Japonica) suggests at least two independent domesticati...

  8. Comparison of partial and complete soil K budgets under intensive rice cropping in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Hoa, N.M.; Janssen, B.H.; Oenema, O.; Dobermann, A.

    2006-01-01

    Crop response to added fertilizer K was often found to be small in trials conducted on favorable soils of tropical rice ecosystems. Hence, applications of only fertilizer N and P were recommended. This has resulted in soil K mining in intensive cropping systems in China, India and other Asian

  9. Degradation Processes of Pesticides Used in Potato Cultivations.

    Science.gov (United States)

    Kurek, M; Barchańska, H; Turek, M

    Potato is one of the most important crops, after maize, rice and wheat. Its global production is about 300 million tons per year and is constantly increasing. It grows in temperate climate and is used as a source of starch, food, and in breeding industry.Potato cultivation requires application of numerous agro-technical products, including pesticides, since it can be affected by insects, weeds, fungi, and viruses. In the European Union the most frequently used pesticides in potato cultivations check are: thiamethoxam, lambda-cyhalothrin and deltamethrin (insecticides), rimsulfuron (herbicide) and metalaxyl (fungicide).Application of pesticides improves crop efficiency, however, as pesticides are not totally selective, it affects also non-target organisms. Moreover, the agrochemicals may accumulate in crops and, as a consequence, negatively influence the quality of food products and consumer health. Additional risks of plant protection products are related to their derivatives, that are created both in the environment (soil, water) and in plant organisms, since many of these compounds may exhibit toxic effects.This article is devoted to the degradation processes of pesticides used in potato crop protection. Attention is also paid to the toxicity of both parent compounds and their degradation products for living organisms, including humans. Information about the level of pesticide contamination in the environment (water, soil) and accumulation level in edible plants complement the current knowledge about the risks associated with widespread use of thiamethoxam, lambda-cyhalothrin and deltamethrin, rimsulfuron and metalaxyl in potato cultivation.

  10. Discrimination rice cropping systems using multi-temporal Proba-V data in the Mekong Delta, Vietnam

    Science.gov (United States)

    Son, Nguyen-Thanh; Chen, Chi-Farn; Chen, Cheng-Ru; Chang, Ly-Yu; Chiang, Shou-Hao; Lau, Khin-Va

    2016-04-01

    Rice is considered a main source of livelihoods for several billions of people worldwide and plays an important role in the economy of many Asian countries. More than just a food source, rice production is regarded as one of the most important components to maintaining political stability and is also a national subject of economic policy due to domestic food consumption and grain exports. Vietnam is globally one of the largest rice producers and suppliers with more than 80% of the exported rice amount produced from the Mekong River Delta. This delta is one of the three deltas in the world most vulnerable to the climate change, causing the potential loss of rice yields. Thus, spatiotemporal information of rice cropping systems is important for agricultural management to ensure food security and rice grain exports. Coarse resolution satellite data such as MODIS demonstrates the applicability for rice mapping at a large scale. However, the use of MODIS data for such a monitoring purpose still reveals a challenging task due to mixed-pixel issues. The Proba-V satellite launched on 7 May 2013 is a potential candidate for this monitoring purpose because the data include four spectral bands (blue, red, near-infrared and mid-infrared) with a swath of 2,285 km with a spatial resolution of 100 m and temporal resolution of 5 days. This study aimed to investigate the applicability of multi-temporal Proba-V data for mapping rice cropping systems in Mekong Delta River, South Vietnam. The data were processed for 2014-2015 rice cropping seasons, following three main steps: (1) construction of smooth time-series NDVI data, (2) classification of rice cropping systems using crop phenological metrics, and (3) accuracy assessment of the mapping results. The results indicated that the smooth time-series NDVI profiles characterized the temporal spectral responses of rice fields through different growing stages of rice plant, which was critically important for understanding rice crop

  11. Association of Dietary Intake and Biomarker Levels of Arsenic, Cadmium, Lead, and Mercury among Asian Populations in the United States: NHANES 2011-2012.

    Science.gov (United States)

    Awata, Hiroshi; Linder, Stephen; Mitchell, Laura E; Delclos, George L

    2017-03-01

    We have recently shown that biomarker levels of selected metals are higher in Asians than in other U.S. ethnic groups, with important differences within selected Asian subgroups. Much of this difference may be dietary in origin; however, this is not well established. We evaluated dietary intake of toxic metals as a source of increased biomarker levels of metals among U.S. Asians. We estimated daily food consumption and dietary intake of arsenic, cadmium, lead, and mercury by combining 24-hr dietary intake recall data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) with data from the USDA Food Composition Intake Database and FDA Total Dietary Study. We analyzed associations between dietary metal intake and biomarker levels of the metals using linear regression. Further, estimated food consumption and metal intake levels were compared between Asians and other racial/ethnic groups (white, black, Mexican American, and other Hispanic) and within three Asian subgroups (Chinese, Indian Asian, and other Asians). Significant associations (p Asians. Asians had the highest daily fish and rice consumption across the racial/ethnic groups. Fish was the major contributor to dietary mercury and total arsenic intake, whereas rice was the major contributor to inorganic arsenic dietary intake. Fish consumption across the Asian subgroups varied, with Asian Indians having lower fish consumption than the other Asian subgroups. Rice consumption was similar across the Asian subgroups. We confirmed that estimated dietary intake of arsenic (total and inorganic) and mercury is significantly associated with their corresponding biomarkers in U.S. Asians, using nationally representative data. In contrast, estimated dietary intake of cadmium and lead were not significantly associated with their corresponding biomarker levels in U.S. Asians. Citation: Awata H, Linder S, Mitchell LE, Delclos GL. 2017. Association of dietary intake and biomarker levels of arsenic

  12. Potential health risk of total arsenic from consumption of farm rice (Oryza sativa) from the southern Caspian Sea littoral and from imported rice in Iran.

    Science.gov (United States)

    Rezaitabar, Soheila; Esmaili-Sari, Abbas; Bahramifar, Nader

    2012-04-01

    In this study, Arsenic (As) was measured in several varieties of imported and local cultivated rice. Soil samples collected from rice farms situated in south Caspian Sea (Iran) were also studied. The mean concentration of As in imported rice, local farmed rice and soil, were determined as 0.28, 0.39 and 3.80 μg g(-1) dry weight, respectively. Estimated daily intake of As through human consumption of imported and local produced rice was 0.77 and 1.074 μg day(-1) kg(-1) B.W., respectively. These values are much lower than the tolerable daily intakes estimated by JECFA. The As concentration in the soil (3.80 μg g(-1) dry) was below acceptable limit for agricultural soil of 20.0 mg kg(-1) as recommended by the European Community (EC). No correlation between the As concentrations in rice and soil samples was found (p > 0.05).

  13. Synthetic Aperture Radar (SAR)-based paddy rice monitoring system: Development and application in key rice producing areas in Tropical Asia

    Science.gov (United States)

    Setiyono, T. D.; Holecz, F.; Khan, N. I.; Barbieri, M.; Quicho, E.; Collivignarelli, F.; Maunahan, A.; Gatti, L.; Romuga, G. C.

    2017-01-01

    Reliable and regular rice information is essential part of many countries’ national accounting process but the existing system may not be sufficient to meet the information demand in the context of food security and policy. Synthetic Aperture Radar (SAR) imagery is highly suitable for detecting lowland paddy rice, especially in tropical region where pervasive cloud cover in the rainy seasons limits the use of optical imagery. This study uses multi-temporal X-band and C-band SAR imagery, automated image processing, rule-based classification and field observations to classify rice in multiple locations across Tropical Asia and assimilate the information into ORYZA Crop Growth Simulation model (CGSM) to generate high resolution yield maps. The resulting cultivated rice area maps had classification accuracies above 85% and yield estimates were within 81-93% agreement against district level reported yields. The study sites capture much of the diversity in water management, crop establishment and rice maturity durations and the study demonstrates the feasibility of rice detection, yield monitoring, and damage assessment in case of climate disaster at national and supra-national scales using multi-temporal SAR imagery combined with CGSM and automated methods.

  14. Butyric acid tolerance of rice mutant M4 families

    Directory of Open Access Journals (Sweden)

    Mauricio Marini Kopp

    2007-01-01

    Full Text Available Hydromorphic soils have a low drainage capacity and are used mainly for the cultivation of irrigated rice.This condition favors the development of anaerobic microorganisms that produce phytotoxic substances. The objective of thisstudy was to evaluate the response of rice mutants to the phytotoxicity caused by butyric acid under anaerobic conditions. Theexperiment consisted of four treatments arranged in a randomized block design. Plants of 40 families were grown in ahydroponic system and the measured variables were root length and length of aerial part (LAP, number of roots (NR androot dry matter (RDM and aerial part dry matter (DMAP. The analysis of variance was performed, the relative performancecalculated and linear regressions were fitted. Only the treatment effect for NR and effect of interaction for LAP were notsignificant. Root length was most affected by the acid and the regressions expressed positive as well as negative effects for acidtolerance in the mutant families.

  15. Climate Change Implications to Irrigated Rice Production in Southern Brazil: A Modelling Approach

    Science.gov (United States)

    Dos Santos, Thiago

    Rice is one of the staple foods for more than three billion people worldwide. When cultivated under irrigated conditions (i.e. lowland rice), rice is one of the most intensive water consumer crops globally. Therefore, representation of rice growth should be integrated into the latest land surface models to allow studies on food security and to ensure that accurate simulations of the bidirectional feedbacks between the land surface and atmosphere take place. In this study, I present a new process-based model for rice fields that includes rice growth and rice irrigation as modules within the Agro-IBIS dynamic agro-ecosystem model. The model includes a series of equations, agricultural management parameters and an irrigation scheme that are specifically tailored for rice crops. The model was evaluated against leaf area index and biomass observations, obtained for one growing season in Rio Grande do Sul state (southern Brazil), and in Los Banos, Philippines. The model accurately captured the temporal dynamics of leaf area index in both the Brazilian and the Philippine sites, and predicted end-of-season biomass with an error of between -9.5% and 11.3% depending on the location and the plant organ. Rice phenology is predicted by the model based on experimentally-derived growth rates, and was evaluated by comparing simulated and observed durations of the four growth phases considered by the model. Agro-IBIS showed a tendency to overestimate the duration of the growth stages between 3% and 16%, but underestimated by 8% the duration of the panicle formation phase in one growing season. The new irrigation model is based on the water balance at the surface and applies irrigation in order to keep the water layer at the paddy field always in the optimum level. A set of climate projections from global climate models under two emission scenarios, and excluding and considering CO2 fertilizations effects, was used to drive the updated Agro-IBIS to estimate the effects of climate

  16. South Asian Cluster

    OpenAIRE

    Ionel Sergiu Pirju

    2014-01-01

    This article aims at presenting the South Asian cluster composed of India, Indonesia, Iran and Malaysia, the intercultural values that characterizes it, the supported leadership style and tracing the main macroeconomic considerations which characterizes them. The research is synchronic, analysing the contemporary situation of these countries without reference to their evolution in time, by using the positivist paradigm that explains the reality at one point. It will be analysed th...

  17. Asian American Adolescent Identity

    OpenAIRE

    Ohm, Julie Juhye

    1999-01-01

    The formation of ego identity in Asian American late adolescents attending Virginia Tech was examined within the frameworks of Erikson's psychosocial theory and Berry, Trimble, and Olmedo's model of acculturation. Ego identity was measured using the Achieved sub-scale of the Revised Version of the Extended Objective Measure of Ego Identity Status, an instrument based on the theoretical constructs of Erikson. Ethnic identity was measured using the Multigroup Ethnic Identity Measure and America...

  18. Asian Media Productions

    DEFF Research Database (Denmark)

    This work consists of 12 essays on different aspects of Asian media by Japanese, European, and American scholars, many of whom have themselves been involved in the production of media forms. Working in the fields of anthropology, media and cultural studies, and on the basis of hands-on research......, they have written a book on the social practices and cultural attitudes of people producing, reading, watching and listening to different kinds of media in Japan, China, Taiwan, Indonesia, Vietnam, Singapore and India....

  19. East Asian welfare regime

    DEFF Research Database (Denmark)

    Abrahamson, Peter

    2017-01-01

    The paper asks if East Asian welfare regimes are still productivist and Confucian? And, have they developed public care policies? The literature is split on the first question but (mostly) confirmative on the second. Care has to a large, but insufficient extent, been rolled out in the region. Pol...... focusing on outcomes or causal links tend to suggest that legacies prevail, but there is (nearly) consensus that Confucianism exercises great influence in the whole region....

  20. Os "camponeses" e o "imperador": Reflexões etnográficas sobre orizicultura intensiva e estratificação social no Sudeste da China rural The "farmers" and the "emperor": Ethnographic reflections on wet-rice cultivation and social stratification in rural Southeastern China

    Directory of Open Access Journals (Sweden)

    Gonçalo Duro dos Santos

    2006-05-01

    Full Text Available Este artigo revisita o tema da distinção social nas sociedades humanas, a partir de material etnográfico recentemente colectado numa aldeia de linhagem situada na região de cultivo intensivo de arroz irrigado do Sudeste da China subtropical. O artigo sugere que as metáforas imperiais de estratificação social usadas pelos "camponeses" desta aldeia para se posicionarem no mundo são parte integrante de um esquema prático de estratificação social, cuja popularidade pode ser parcialmente explicada pelo facto de este esquema se encontrar profundamente enredado num modo de vida agrário imemorial assente na prática de orizicultura intensiva. Sugere-se ainda que este esquema cultural de estratificação social com ressonâncias orizícolas não é apenas um "modelo ideológico de", mas é também um " modelo ideológico para" a distinção social, que está por isso sujeito ao poder transformativo da história.This article revisits the topic of social distinction in human societies with ethnographic material recently collected in a Cantonese lineage-village situated in the wet-rice farming region of subtropical Southeastern China. The article suggests that the imperial metaphor of social stratification is frequently used by the village "farmers" to position themselves in the world is part and parcel of a practical scheme of social stratification whose popularity can be partially explained by it being deeply rooted in a way of life based on the immemorial practice of wet-rice farming. It is also suggested that this wet-rice permeated popular scheme of social stratification is not only an "ideological model of" but is also an " ideological model for" social distinction that is thus subject to the transforming power of history.

  1. Silicon fertilization and soil water tensions on rice development and yield

    Directory of Open Access Journals (Sweden)

    Jakeline R. de Oliveira

    2016-02-01

    Full Text Available ABSTRACT The cultivation of upland rice (Oryza sativa in Brazil occurs mainly in the Cerrado, a region with adverse weather conditions. The use of silicon in its cultivation becomes important, since this nutrient provides higher rigidity, lower transpiration and higher resistance to dry spells in rice plants. The objective of the present study was to evaluate the effect of silicon fertilization and soil water tensions on upland rice development and yield in a Cerrado Oxisol. A 5 x 5 fractionated factorial with five soil water tensions (0, 15, 30, 45 and 60 kPa and five silicon doses (0, 120, 240, 480 and 960 mg dm-3 was used, which were distributed in a randomized block design, with four replicates. Plant height, number of tillers, number of panicles, number of grains per panicle, numbers of full and empty grains and percentage of empty grains were evaluated. Silicon fertilization promotes increased tillering in rice plants at the dose of 960 mg dm-3. The numbers of tillers and panicles decreased with the application of silicon up to the doses of 460 and 490 mg dm-3, respectively. The increase in soil water tensions reduced plant height and the number of full grains, and increased the percentage of empty grains of upland rice.

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

    Science.gov (United States)

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

    2015-10-29

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

  3. Expression Variations of miRNAs and mRNAs in Rice (Oryza sativa).

    Science.gov (United States)

    Wen, Ming; Xie, Munan; He, Lian; Wang, Yushuai; Shi, Suhua; Tang, Tian

    2016-12-31

    Differences in expression levels are an important source of phenotypic variation within and between populations. MicroRNAs (miRNAs) are key players in post-transcriptional gene regulation that are important for plant development and stress responses. We surveyed expression variation of miRNAs and mRNAs of six accessions from two rice subspecies Oryza sativa L. ssp. indica and Oryza sativa L. ssp. japonica using deep sequencing. While more than half (53.7%) of the mature miRNAs exhibit differential expression between grains and seedlings of rice, only 11.0% show expression differences between subspecies, with an additional 2.2% differentiated for the development-by-subspecies interaction. Expression variation is greater for lowly conserved miRNAs than highly conserved miRNAs, whereas the latter show stronger negative correlation with their targets in expression changes between subspecies. Using a permutation test, we identified 51 miRNA-mRNA pairs that correlate negatively or positively in expression level among cultivated rice. Genes involved in various metabolic processes and stress responses are enriched in the differentially expressed genes between rice indica and japonica subspecies. Our results indicate that stabilizing selection is the major force governing miRNA expression in cultivated rice, albeit positive selection may be responsible for much of the between-subspecies expression divergence. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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

    Science.gov (United States)

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

    2011-07-01

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

  5. Perspectives in asian rhinoplasty.

    Science.gov (United States)

    Jang, Yong Ju; Yi, Jong Sook

    2014-04-01

    Asian patients present with relatively poorly developed dorsal and tip height and thicker skin, so augmentation rhinoplasty is the most commonly performed rhinoplasty procedure. Tip surgery using autologous cartilage followed by dorsal augmentation using an alloplastic implant material is the most widely performed surgical procedure for augmentation rhinoplasty on Asian patients. Cartilage tip grafting procedures, including shield grafting, multilayer tip grafting, onlay grafting, and modified vertical dome division, are key maneuvers for building up and providing better definition on a relatively poorly developed Asian tip. When performing primary cosmetic dorsal augmentation using alloplastic implants, the implant material should be selected according to the surgeon's experience, the pros and cons of available dorsal implant materials, and host factors such as skin thickness, associated deformities, and aesthetic goals. The costal cartilage is best reserved for difficult revisions, except in a limited number of primary cases who present with a very poorly developed nasal skeleton and thick skin. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

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

    Science.gov (United States)

    Vibol, S; Towprayoon, S

    2010-02-01

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

  7. Levantamento fitossociológico das comunidades de plantas infestantes em áreas de produção de arroz irrigado cultivado sob diferentes sistemas de manejo Phyto-sociological survey of weed communities in flooded rice areas cultivated under different management systems

    Directory of Open Access Journals (Sweden)

    E.A.L. Erasmo

    2004-06-01

    flooded rice areas of two different co-ops located in Formoso do Araguaia, Tocantins, Brazil: Mista Rural Vale do Javaés Co-op and Agroindustrial Rio Formoso Co-op. Three different 1 ha areas were selected: 1 - area under 5- year no crop rotation system (rice/fallow; 2 - area under 5- year rice/soybean crop rotation system; and 3 - area under 2- year rice/water-melon crop rotation system. The characterization and phyto-sociological studies of the weed community were carried out using square samples of 1.0 x 1.0 meter randomly placed inside each selected area (Inventory Square Method. Eight families and 16 species were identified in the no-crop rotation area, with the family Poaceae presenting the largest number of species and Fimbristylis miliacea (Cyperaceae presenting the highest relative importance value (84.46%. The 5-year rice soybean crop rotation system area had 8 families and 12 species with the Poaceae and Cyperaceae presenting the largest number of species and Cyperus esculentus (Cyperaceae the highest relative importance value (91. 40 %. Six families and 8 species were identified in the 2-year rice/water-melon crop rotation system area, with the Euphorbiaceae and Lamiaceae families presenting the largest number of species. Physalis angulata (Solanaceae showed the highest relative importance value (153.10%, followed by Eclipta alba (Compositae and Hyptis lophanta (Lamiaceae with a relative importance value of 40.50% and 37.60%, respectively.

  8. Fungal cultivation on glass-beads

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    Transcription of various bioactive compounds and enzymes are dependent on fungal cultivation method. In this study we cultivate Fusarium graminearum and Fusarium solani on glass-beads with liquid media in petri dishes as an easy and inexpensive cultivation method, that resembles in secondary...... metabolite production to agar-cultivation but with an easier and more pure RNA-extraction of total fungal mycelia....

  9. Accelerated Solvent Extraction of Insecticides from Rice Hulls, Rice Bran, and Polished Rice Grains.

    Science.gov (United States)

    Teló, Gustavo Mack; Senseman, Scott Allen; Marchesan, Enio; Camargo, Edinalvo Rabaioli; Carson, Katherine

    2017-03-01

    Analysis of pesticide residues in irrigated rice grains is important for food security. In this study, we analyzed accelerated solvent extraction (ASE) conditions for the extraction of thiamethoxam and chlorantraniliprole insecticides from rice hulls, rice bran, and polished rice grains. Several variables, including extraction solvent, extraction temperature, extraction pressure, cell size, static extraction time, and sample concentration, were investigated. The average recoveries of the three matrixes were between 89.7 and 109.7% at the fortification level of 0.75 mg/kg. The optimum ASE operating conditions were acetonitrile (100%) as extraction solvent, extraction temperature of 75°C for rice hulls and 100°C for rice bran and polished rice grains, extraction cell pressure of 10.3 MPa, 22 mL cell size, and two extraction cycles. The total extraction time was approximately 25 min. The extracted volume was evaporated to dryness and the residues were redissolved in 2 mL acetonitrile after 1 min of vortex-shaking. Thiamethoxam and chlorantraniliprole were analyzed by ultra-HPLC with tandem MS. In conclusion, ASE in rice hulls, rice bran, and polished rice grains offers the possibility of a fast and simple method for obtaining a quantitative extraction of the studied pesticides.

  10. SUSTAINING PADDY SELF-SUFFICIENCY AND LAND DEMANDS IN SABAH, MALAYSIA: A STRUCTURAL PADDY AND RICE ECONOMETRIC MODEL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Wong Kelly_Kai_Seng

    2017-01-01

    Full Text Available The objective of this study is to construct an econometric commodity model in order to forecast the long term rice production performance of the state of Sabah, Malaysia. The baseline projection shows that the Sabah rice self-sufficiency is estimated to achieve approximately38% in the next 10 years due to the scarcity of the suitable land bank allocate for paddy cultivation. In order to achieve 60% of targeted rice self-sufficiency level (SSL, the size of land for paddy cultivation must be increased in Sabah. Based on the scenario simulation projection result, the expansion of paddy cultivation area will contribute a positively to the industrial rice production and consequently achieving the expected 60% of SSL by the end of 2024. In a nutshell, the state government of Sabah possess state autonomy on the land management, thus the state government plays a significant key role on promoting the local rice self-sufficiency level in the long-term period

  11. Genome wide re-sequencing of newly developed Rice Lines from common wild rice (Oryza rufipogon Griff.) for the identification of NBS-LRR genes.

    Science.gov (United States)

    Liu, Wen; Ghouri, Fozia; Yu, Hang; Li, Xiang; Yu, Shuhong; Shahid, Muhammad Qasim; Liu, Xiangdong

    2017-01-01

    -sequencing, which proved to be a useful tool to exploit elite NBS-LRR genes in wild rice. The data here provide a foundation for future work aimed at dissecting the genetic basis of disease resistance in rice, and the two wild rice lines will be useful germplasm for the molecular improvement of cultivated rice.

  12. Activity and diversity of methanotrophs in the soil-water interface and rhizospheric soil from a flooded temperate rice field.

    Science.gov (United States)

    Ferrando, L; Tarlera, S

    2009-01-01

    To combine molecular and cultivation techniques to characterize the methanotrophic community in the soil-water interface (SWI) and rhizospheric soil from flooded rice fields in Uruguay, a temperate region in South America. A novel type I, related to the genus Methylococcus, and three type II methanotrophs were isolated from the highest positive dilution steps from the most probable number (MPN) counts. Potential methane oxidation activities measured in slurried samples were higher in the rhizospheric soil compared to the SWI and were stimulated by N-fertilization. PmoA (particulate methane monooxygenase) clone libraries were constructed for both rice microsites. SWI clones clustered in six groups related to cultivated and uncultivated members from different ecosystems of the genera Methylobacter, Methylomonas, Methylococcus and a novel type I sublineage while cultivation and T-RFLP (terminal restriction fragment length polymorphism) analysis confirmed the presence of type II methanotrophs. Cultivation techniques, cloning analysis and T-RFLP fingerprinting of the pmoA gene revealed a diverse methanotrophic community in the rice rhizospheric soil and SWI. This study reports, for the first time, the analysis of the methanotrophic diversity in rice SWI and this diversity may be exploited in reducing methane emissions.

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

    Science.gov (United States)

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

  14. More than one way to evolve a weed: parallel evolution of U.S. weedy rice through independent genetic mechanisms

    Science.gov (United States)

    Many crop species were independently selected for a shared suite of “domestication traits,” which facilitates their use for studies of parallel evolution. Within domesticated rice (Oryza sativa), there has also been independent evolution of weedy strains from different cultivated varieties. This mak...

  15. Effect Of Shade Organic Materials And Varieties On Growth And Production Of Upland Rice

    Directory of Open Access Journals (Sweden)

    Jonatan Ginting

    2015-01-01

    Full Text Available Abstract There is a shade factor and low organic matter content of the soil is a problem that needs to be addressed in the development of upland rice cultivation as intercrops in the plantation area. Based on these considerations then one study that needs to be done is to conduct experiments on the effect of shade factor combined with the the provision of the organic material to the some varieties of upland rice that has been recommended nationally. The objective of experiment is to study the influence of shade organic materials and varieties on the growth and production of upland rice. This research using experimental design of Split - Split Plot Design with 3 treatment factors and 3 replications or blocks. The first factor is the treatment of shade with 3 levels shade percentage 0 20 and 40. The second factor is the dosage of organic material consists of 3 levels 0 g polybag 25 g polybag 50 g polybag and 75 g polybag. The third factor is the treatment of varieties consists of 4 types of upland rice varieties Si Kembiri Situ Patengggang Situ Bagendit and Tuwoti. The research results showed that the effect of shade on upland rice varieties decrease number of tillers number of panicles number of productive grains grain production per hill of uplnd rice plants and total sugar content of upland rice plants. Effect of organic matter increases number of panicles number of productive grains grain production per hill of upland rice plants and total sugar content of upland rice plants. It is known that the the variety of Situ Patenggang provides better growth and production compared with three other varieties Si Kembiri Situ Bagendit and Tuwoti in shaded conditions.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Yi Zhou

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

  18. 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...

  19. Putting Plant Genetic Diversity and Variability at Work for Breeding: Hybrid Rice Suitability in West Africa

    Directory of Open Access Journals (Sweden)

    Raafat El-Namaky

    2017-07-01

    Full Text Available Rice is a staple food in West Africa, where its demand keeps increasing due to population growth. Hence, there is an urgent need to identify high yielding rice cultivars that fulfill this demand locally. Rice hybrids are already known to significantly increase productivity. This study evaluated the potential of Asian hybrids with good adaptability to irrigated and rainfed lowland rice areas in Mali, Nigeria, and Senegal. There were 169 hybrids from China included in trials at target sites during 2009 and 2010. The genotype × environment interaction was highly significant (p < 0.0001 for grain yield indicating that the hybrids’ and their respective cultivar checks’ performance differed across locations. Two hybrids had the highest grain yield during 2010 in Mali, while in Nigeria, four hybrids in 2009 and one hybrid in 2010 had higher grain yield and matured earlier than the best local cultivar. The milling recovery, grain shape and cooking features of most hybrids had the quality preferred by West African consumers. Most of the hybrids were, however, susceptible to African rice gall midge (AfRGM and Rice Yellow Mottle Virus (RMYV isolate Ng40. About 60% of these hybrids were resistant to blast. Hybrids need to incorporate host plant resistant for AfRGM and RYMV to be grown in West Africa.

  20. Defense Responses in Rice Induced by Silicon Amendment against Infestation by the Leaf Folder Cnaphalocrocis medinalis.

    Science.gov (United States)

    Han, Yongqiang; Li, Pei; Gong, Shaolong; Yang, Lang; Wen, Lizhang; Hou, Maolin

    2016-01-01

    Silicon (Si) amendment to plants can confer enhanced resistance to herbivores. In the present study, the physiological and cytological mechanisms underlying the enhanced resistance of plants with Si addition were investigated for one of the most destructive rice pests in Asian countries, the rice leaf folder, Cnaphalocrocis medinalis (Guenée). Activities of defense-related enzymes, superoxide dismutase, peroxidase, catalase, phenylalanine ammonia-lyase, and polyphenol oxidase, and concentrations of malondialdehyde and soluble protein in leaves were measured in rice plants with or without leaf folder infestation and with or without Si amendment at 0.32 g Si/kg soil. Silicon amendment significantly reduced leaf folder larval survival. Silicon addition alone did not change activities of defense-related enzymes and malondialdehyde concentration in rice leaves. With leaf folder infestation, activities of the defense-related enzymes increased and malondialdehyde concentration decreased in plants amended with Si. Soluble protein content increased with Si addition when the plants were not infested, but was reduced more in the infested plants with Si amendment than in those without Si addition. Regardless of leaf folder infestation, Si amendment significantly increased leaf Si content through increases in the number and width of silica cells. Our results show that Si addition enhances rice resistance to the leaf folder through priming the feeding stress defense system, reduction in soluble protein content and cell silicification of rice leaves.

  1. Defense Responses in Rice Induced by Silicon Amendment against Infestation by the Leaf Folder Cnaphalocrocis medinalis.

    Directory of Open Access Journals (Sweden)

    Yongqiang Han

    Full Text Available Silicon (Si amendment to plants can confer enhanced resistance to herbivores. In the present study, the physiological and cytological mechanisms underlying the enhanced resistance of plants with Si addition were investigated for one of the most destructive rice pests in Asian countries, the rice leaf folder, Cnaphalocrocis medinalis (Guenée. Activities of defense-related enzymes, superoxide dismutase, peroxidase, catalase, phenylalanine ammonia-lyase, and polyphenol oxidase, and concentrations of malondialdehyde and soluble protein in leaves were measured in rice plants with or without leaf folder infestation and with or without Si amendment at 0.32 g Si/kg soil. Silicon amendment significantly reduced leaf folder larval survival. Silicon addition alone did not change activities of defense-related enzymes and malondialdehyde concentration in rice leaves. With leaf folder infestation, activities of the defense-related enzymes increased and malondialdehyde concentration decreased in plants amended with Si. Soluble protein content increased with Si addition when the plants were not infested, but was reduced more in the infested plants with Si amendment than in those without Si addition. Regardless of leaf folder infestation, Si amendment significantly increased leaf Si content through increases in the number and width of silica cells. Our results show that Si addition enhances rice resistance to the leaf folder through priming the feeding stress defense system, reduction in soluble protein content and cell silicification of rice leaves.

  2. 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.

  3. Aroma chemistry of African Oryza glaberrima and Oryza sativa rice and their interspecific hybrids.

    Science.gov (United States)

    Cho, Sungeun; Nuijten, Edwin; Shewfelt, Robert L; Kays, Stanley J

    2014-03-15

    To increase rice production in Africa, considerable research has focused on creating interspecific hybrids between African (Oryza glaberrima Steud.) and Asian (O. sativa L.) rice in an attempt to obtain the positive attributes of each in new cultivars. Since flavor is a key criterion in consumer acceptance of rice, as an initial inquiry we characterized and compared the aroma chemistry of selected cultivars of African O. sativa ssp. japonica, O. sativa ssp. indica, O. glaberrima, and their interspecific hybrids grown in West Africa, using gas chromatography-mass spectrometry, gas chromatography-olfactometry and descriptive sensory analysis. Of 41 volatiles identified across seven representative rice cultivars grown in West Africa, 3,5,5-trimethyl-2-cyclopenten-1-one, styrene, eucalyptol, linalool, myrtenal and L-α-terpineol had not been previously reported in rice. Thirty-three odor-active compounds were characterized. 4-Ethylphenol and (E,E)-2,4-heptadienal were unique to O. glaberrima, and pyridine, eucalyptol and myrtenal were described only in an interspecific hybrid. Descriptive sensory analysis indicated 'cooked grain', 'barny' and 'earthy' attributes were statistically different among the cultivars. The aroma chemistry data suggest that it should be possible to separate African cultivars into distinct flavor types thereby facilitating selection of new cultivars with superior flavor in African rice breeding programs. © 2013 Society of Chemical Industry.

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

    Science.gov (United States)

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

    2014-01-01

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

  5. South Asian Cluster

    Directory of Open Access Journals (Sweden)

    Ionel Sergiu Pirju

    2014-12-01

    Full Text Available This article aims at presenting the South Asian cluster composed of India, Indonesia, Iran and Malaysia, the intercultural values that characterizes it, the supported leadership style and tracing the main macroeconomic considerations which characterizes them. The research is synchronic, analysing the contemporary situation of these countries without reference to their evolution in time, by using the positivist paradigm that explains the reality at one point. It will be analysed the overall cluster with the existing interactions between the countries that composes it, while the article being one of information will avoid building recommendation, or new theories.

  6. Immunizations and Asians and Pacific Islanders

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Immunizations Immunizations and Asians and Pacific Islanders Asian/Pacific Islander ... 35 months reached the Healthy People goal for immunizations for hepatitis B, MMR (measles-mumps-rubella), polio ...

  7. Effects of beneficial microorganisms on lowland rice development.

    Science.gov (United States)

    Nascente, Adriano Stephan; de Filippi, Marta Cristina Corsi; Lanna, Anna Cristina; de Sousa, Thatyane Pereira; de Souza, Alan Carlos Alves; da Silva Lobo, Valácia Lemes; da Silva, Gisele Barata

    2017-11-01

    Microorganisms can promote plant growth by increasing phytomass production, nutrient uptake, photosynthesis rates, and grain yield, which can result in higher profits for farmers. However, there is limited information available about the physiological characteristics of lowland rice after treatment with beneficial microorganisms in the tropical region. This study aimed to determine the effects of different beneficial microorganisms and various application forms on phytomass production, gas exchange, and nutrient contents in the lowland rice cultivar 'BRS Catiana' in a tropical region. The experiment was performed under greenhouse conditions utilizing a completely randomized design and a 7 × 3 + 1 factorial scheme with four replications. The treatments consisted of seven microorganisms, including the rhizobacterial isolates BRM 32113, BRM 32111, BRM 32114, BRM 32112, BRM 32109, and BRM 32110 and Trichoderma asperellum pooled isolates UFRA-06, UFRA-09, UFRA-12, and UFRA-52, which were applied using three different methods (microbiolized seed, microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS), and microbiolized seed + plant spraying with a microorganism suspension at 7 and 15 DAS) with a control (water). The use of microorganisms can provide numerous benefits for rice in terms of crop growth and development. The microorganism types and methods of application positively and differentially affected the physiological characteristics evaluated in the experimental lowland rice plants. Notably, the plants treated with the bioagent BRM 32109 on the seeds and on seeds + soil produced plants with the highest dry matter biomass, gas exchange rate, and N, P, Fe, and Mg uptake. Therefore, our findings indicate strong potential for the use of microorganisms in lowland rice cultivation systems in tropical regions. Currently, an additional field experiment is in its second year to validate the beneficial result reported

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

    African Journals Online (AJOL)

    Z. variegatus 1. 0.688. 1.037. Locust. L. migratoides. 1. 1.023. 1.037. Discussion. Viral disease due to RYMV had been a major challenge in rice production in Nigeria since 1976 when it was reported by Rossel et al. (1982). Areas of rice production in Nigeria where the virus had been detected included. Badeggi, Ibadan ...

  9. Asian American Dietary Sources of Sodium and Salt Behaviors Compared with Other Racial/ethnic Groups, NHANES, 2011-2012.

    Science.gov (United States)

    Firestone, Melanie J; Beasley, Jeannette M; Kwon, Simona C; Ahn, Jiyoung; Trinh-Shevrin, Chau; Yi, Stella S

    2017-01-01

    Asian Americans consume more sodium than other racial/ethnic groups. The purpose of this analysis was to describe major sources of sodium intake to inform sodium reduction initiatives. Cross-sectional data on adults (aged >18 years) from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 with one 24-hour dietary recall were analyzed (n=5,076). Population proportions were calculated from "What We Eat in America" (WWEIA) food categories. Asian Americans had a higher sodium density vs adults of other racial/ethnic groups (means in mg/1000kcal: Asian American, 2031.1; Hispanic,1691.6; White: 1666.5; Black: 1655.5; Pfood categories, in contrast to Hispanics (43.6%), Whites (39.0%), and Blacks (36.0%). Four food categories were a top source of sodium for Hispanics, Whites, Blacks, and others, but not among Asian Americans: cold cuts and cured meats; meat mixed dishes; eggs and omelets; and cheese. The top three food category sources of sodium among Asians were soups, rice, and yeast breads accounting for 28.9% of dietary sodium. Asian Americans were less likely to add salt at the table, but used salt in food preparation 'very often' (P for both ethnic groups with highest consumption in Asian Americans. Given the smaller number of food categories contributing to sodium intake in Asian Americans, results imply that targeted activities on a few food items would have a large impact on reducing sodium intake in this group.

  10. 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.

  11. Fuels and chemicals from rice straw in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, R. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Technische Chemie; Ramadan, A.B. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Technische Chemie]|[Atomic Energy Authority (AEA), Cairo (Egypt). National Centre for Nuclear Safety and Radiation Control

    2007-10-15

    In Egypt rice cultivation in the river Nile Delta produces large amounts of rice straw as residue. Assuming that about 20% were used for other purposes about 2.8 Mt were left on the fields for burning within a period of 30 days to get quickly rid of leftover debris. The resulting emissions give a significant contribution to the air pollution called the ''Black Cloud''. A suitable technology for the use of rice straw is an important contribution to reduce air pollution and gives a significant contribution to use biomass as renewable energy in Egypt. Based on that fact rice straw was studied as possible feedstock for the BIOLIQ process. The BIOLIQ process which is under development at the Forschungszentrum Karlsruhe (Germany) is a two-step process for the production of chemicals, fuels or electricity from lignocellulosic biomass with high ash content. In the first step the biomass is liquefied by fast pyrolysis. The pyrolysis char and the pyrolysis liquid are mixed to form a slurry. In the second step the pumpable slurry is used to produce syngas in a pressurised entrained flow gasifier. After gas cleaning and conditioning the syngas is used for the production of fuels, chemicals and electricity as by-product. In this work rice straw is studied as a possible feedstock for fast pyrolysis and slurry preparation. First the Egyptian rice straw was chemically characterised. Ultimate analysis of rice straw showed an elemental composition of 47,8% C, 6,0 %H and 45,3% O, (daf). According to the elemental composition the HHV was calculated to be about 18,1 MJ/Kg (Dulong) up to 20,5 MJ/kg (Ebeling). Based on the experimental HHV 15,3 MJ/kg (rice straw dry, 18% ash) the HHV on a moisture and ash free basis was calculated to be 18,7 MJ/kg. According to the literature the lignin, hemicellulose and cellulose contents of rice straw were about 12%, 28% and 60%, respectively. The rice straw was chopped and sieved (2 mm sieve) and most of the straw dust was

  12. Controlling docks by stubble cultivation

    OpenAIRE

    Dierauer, Hansueli; Siegrist, Franziska; Weidmann, Gilles

    2017-01-01

    The stubble cultivation cuts the dock roots below growth points. The vegetative plant parts are then cut off from the water and nutrient supply, and regrowth is inhibited. Practical recommendation • Summer dock treatment is especially worthwhile in dry summers with catch crop cultivation and after early maturing crops (winter barley, whole-crop silage) or with an early tillage of grass-clover. • After grass-clover lay or cereal harvest, undercut the dock plants at a depth of 12-15 cm...

  13. The long and the short of it: SD1 polymorphism and the evolution of growth trait divergence in U.S. weedy rice.

    Science.gov (United States)

    Reagon, Michael; Thurber, Carrie S; Olsen, Kenneth M; Jia, Yulin; Caicedo, Ana L

    2011-09-01

    Growth-related traits, such as greater height, greater biomass, faster growth rate and early flowering, are thought to enhance competitiveness of agricultural weeds. However, weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.), displays variation for growth traits. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Through a common garden experiment, we investigated whether growth trait divergence has occurred among U.S. weeds and their putative cultivated progenitors. We also determined polymorphism patterns in the growth candidate gene, SD1, to assess its possible role in the evolution of divergent phenotypes. We found considerable growth trait variation among weed groups, suggesting that growth trait convergence is not evident among weedy populations. Phenotypic divergence of weedy rice from cultivated ancestors is most apparent for flowering time. Introgression of a chromosomal block containing the SD1 allele from tropical japonica, the predominant U.S. rice cultivar, was detected in one weedy rice population and is associated with a change in growth patterns in this group. This study demonstrates the role of introgressive hybridization in evolutionary divergence of an important weed. © 2011 Blackwell Publishing Ltd.

  14. The Birth of a Black Rice Gene and Its Local Spread by Introgression

    Science.gov (United States)

    Oikawa, Tetsuo; Maeda, Hiroaki; Oguchi, Taichi; Yamaguchi, Takuya; Tanabe, Noriko; Ebana, Kaworu; Yano, Masahiro; Izawa, Takeshi

    2015-01-01

    The origin and spread of novel agronomic traits during crop domestication are complex events in plant evolution. Wild rice (Oryza rufipogon) has red grains due to the accumulation of proanthocyanidins, whereas most cultivated rice (Oryza sativa) varieties have white grains induced by a defective allele in the Rc basic helix-loop-helix (bHLH) gene. Although the events surrounding the origin and spread of black rice traits remain unknown, varieties with black grains due to anthocyanin accumulation are distributed in various locations throughout Asia. Here, we show that the black grain trait originated from ectopic expression of the Kala4 bHLH gene due to rearrangement in the promoter region. Both the Rc and Kala4 genes activate upstream flavonol biosynthesis genes, such as chalcone synthase and dihydroflavonol-4-reductase, and downstream genes, such as leucoanthocyanidin reductase and leucoanthocyanidin dioxygenase, to produce the respective specific pigments. Genome analysis of 21 black rice varieties as well as red- and white-grained landraces demonstrated that black rice arose in tropical japonica and its subsequent spread to the indica subspecies can be attributed to the causal alleles of Kala4. The relatively small size of genomic fragments of tropical japonica origin in some indica varieties indicates that refined introgression must have occurred by natural crossbreeding in the course of evolution of the black trait in rice. PMID:26362607

  15. Investigating Yield Variability and Inefficiency in Rice Production: A Case Study in Central China

    Directory of Open Access Journals (Sweden)

    Zhihai Yang

    2016-08-01

    Full Text Available Insufficient and high variability in rice yield is a threat to food security in China, prompting the need for strategies to mitigate yield variability and increase productivity. This study investigates the presence of production risk and technical inefficiency for a sample of rice farms in the Xiangyang city of China using a stochastic production frontier framework. Results from the risk function reveal that labor and better soil quality have significant risk-reducing effects while machinery exerts a significant risk-increasing effect on rice production. The estimated mean technical efficiency score is 84%, suggesting that, on average, farmers could increase their rice production by 16%, without increasing the existing input levels by improving their management techniques. Factors that significantly affect technical efficiency are the age of farmers, female ratio, access and use of extension services, off-farm income, and the size of cultivated land. Results from this study suggest that yield variability and technical inefficiency in rice production can be reduced by appropriate choice of input combinations and elimination of mistakes in the production process through efficient management practices. Strategies, such as providing better extension services, loosening liquidity constraints facing farmers, and expanding rice farmers’ producing area, would help to achieve minimum inefficiency in production.

  16. Expansion of the biocontrol spectrum of foliar diseases in rice with combinations of rhizobacteria

    Directory of Open Access Journals (Sweden)

    Ismail Teodoro de Souza Júnior

    Full Text Available ABSTRACT The cultivation of irrigated rice is subject to the occurrence of various diseases, where damage causes losses in productivity. Alternatives are currently being sought to control these diseases, with biocontrol a viable possibility. With the aim of broadening the spectrum of action of biocontrol, this study evaluated the effect of combinations of biocontrol bacteria on rice blast (Pyricularia grisea, brown spot (Bipolaris oryzae and leaf scald (Gerlachia oryzae in rice plants. The effect of isolate combinations was assessed by microbiolization of seeds from the rice cultivar El Paso L144 with suspensions of the bacteria DFs185 (Pseudomonas synxantha, DFs223 (P. fluorescens, DFs306 (unidentified, DFs416 and DFs418 (Bacillus sp., used individually or in a combination of two, three or four compatible isolates. Seeds treated with Carboxin Thiram fungicide (T+F at a final dosage corresponding to 3 ml kg-1 were used as control. Considering the leaf diseases together, eight treatments significantly controlled all three diseases, and were superior to the treatment with fungicide. Among these treatments, seven were combinations. Only the DFs306 bacteria were able to control the three diseases when used individually. It can therefore be presumed that combinations of bacteria, when microbiolized in rice seeds, can broaden the spectrum of action for the control of rice blast, brown spot and leaf scald.

  17. Transcriptome Analysis of Early Responsive Genes in Rice during Magnaporthe oryzae Infection

    Directory of Open Access Journals (Sweden)

    Yiming Wang

    2014-12-01

    Full Text Available Rice blast disease caused by Magnaporthe oryzae is one of the most serious diseases of cultivated rice (Oryza sativa L. in most rice-growing regions of the world. In order to investigate early response genes in rice, we utilized the transcriptome analysis approach using a 300 K tilling microarray to rice leaves infected with compatible and incompatible M. oryzae strains. Prior to the microarray experiment, total RNA was validated by measuring the differential expression of rice defense-related marker genes (chitinase 2, barwin, PBZ1, and PR-10 by RT-PCR, and phytoalexins (sakuranetin and momilactone A with HPLC. Microarray analysis revealed that 231 genes were up-regulated (>2 fold change, p < 0.05 in the incompatible interaction compared to the compatible one. Highly expressed genes were functionally characterized into metabolic processes and oxidation-reduction categories. The oxidative stress response was induced in both early and later infection stages. Biotic stress overview from MapMan analysis revealed that the phytohormone ethylene as well as signaling molecules jasmonic acid and salicylic acid is important for defense gene regulation. WRKY and Myb transcription factors were also involved in signal transduction processes. Additionally, receptor-like kinases were more likely associated with the defense response, and their expression patterns were validated by RT-PCR. Our results suggest that candidate genes, including receptor-like protein kinases, may play a key role in disease resistance against M. oryzae attack.

  18. Dating rice remains through phytolith carbon-14 study reveals domestication at the beginning of the Holocene.

    Science.gov (United States)

    Zuo, Xinxin; Lu, Houyuan; Jiang, Leping; Zhang, Jianping; Yang, Xiaoyan; Huan, Xiujia; He, Keyang; Wang, Can; Wu, Naiqin

    2017-06-20

    Phytolith remains of rice (Oryza sativa L.) recovered from the Shangshan site in the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation. However, because of the poor preservation of macroplant fossils, many radiocarbon dates were derived from undifferentiated organic materials in pottery sherds. These materials remain a source of debate because of potential contamination by old carbon. Direct dating of the rice remains might serve to clarify their age. Here, we first validate the reliability of phytolith dating in the study region through a comparison with dates obtained from other material from the same layer or context. Our phytolith data indicate that rice remains retrieved from early stages of the Shangshan and Hehuashan sites have ages of approximately 9,400 and 9,000 calibrated years before the present, respectively. The morphology of rice bulliform phytoliths indicates they are closer to modern domesticated species than to wild species, suggesting that rice domestication may have begun at Shangshan during the beginning of the Holocene.

  19. A practicable detection system for genetically modified rice by SERS-barcoded nanosensors.

    Science.gov (United States)

    Chen, Kun; Han, Heyou; Luo, Zhihui; Wang, Yanjun; Wang, Xiuping

    2012-04-15

    Since the global cultivation of genetically modified crops constantly expands, it remains a high demand to establish different ways to sort food and feed that consist or contain genetically modified organisms. Surface-enhanced Raman scattering (SERS) spectroscopy is a flexible tool for biological analysis due to its excellent properties for detecting wide varieties of target biomolecules including nucleic acids. In the present study, a SERS-barcoded nanosensor was developed to detect Bacillus thuringiensis (Bt) gene-transformed rice expressing insecticidal proteins. The barcoded sensor was designed by encapsulation of gold nanoparticles with silica and conjugation of oligonucleotide strands for targeting DNA strands. The transition between the cry1A(b) and cry1A(c) fusion gene sequence was used to construct a specific SERS-based detection method with a detection limit of 0.1 pg/mL. In order to build the determination models to screen transgene, a series mixture of Bt rice and normal rice were prepared for SERS assay, and the limit of detection was 0.1% (w/w) transgenic Bt rice relative to normal rice. The sensitivity and accuracy of the SERS-based assay was comparable with real-time PCR. The SERS-barcoded analytical method would provide precise detection of transgenic rice varieties but also informative supplement to avoid false positive outcomes. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  20. Are habitat fragmentation, local adaptation and isolation-by-distance driving population divergence in wild rice Oryza rufipogon?

    Science.gov (United States)

    Zhao, Yao; Vrieling, Klaas; Liao, Hui; Xiao, Manqiu; Zhu, Yongqing; Rong, Jun; Zhang, Wenju; Wang, Yuguo; Yang, Ji; Chen, Jiakuan; Song, Zhiping

    2013-11-01

    Habitat fragmentation weakens the connection between populations and is accompanied with isolation by distance (IBD) and local adaptation (isolation by adaptation, IBA), both leading to genetic divergence between populations. To understand the evolutionary potential of a population and to formulate proper conservation strategies, information on the roles of IBD and IBA in driving population divergence is critical. The putative ancestor of Asian cultivated rice (Oryza sativa) is endangered in China due to habitat loss and fragmentation. We investigated the genetic variation in 11 Chinese Oryza rufipogon populations using 79 microsatellite loci to infer the effects of habitat fragmentation, IBD and IBA on genetic structure. Historical and current gene flows were found to be rare (mh  = 0.0002-0.0013, mc  = 0.007-0.029), indicating IBD and resulting in a high level of population divergence (FST  = 0.343). High within-population genetic variation (HE  = 0.377-0.515), relatively large effective population sizes (Ne  = 96-158), absence of bottlenecks and limited gene flow were found, demonstrating little impact of recent habitat fragmentation on these populations. Eleven gene-linked microsatellite loci were identified as outliers, indicating local adaptation. Hierarchical AMOVA and partial Mantel tests indicated that population divergence of Chinese O. rufipogon was significantly correlated with environmental factors, especially habitat temperature. Common garden trials detected a significant adaptive population divergence associated with latitude. Collectively, these findings imply that IBD due to historical rather than recent fragmentation, followed by local adaptation, has driven population divergence in O. rufipogon. © 2013 John Wiley & Sons Ltd.

  1. Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management.

    Science.gov (United States)

    An, Ning; Fan, Mingsheng; Zhang, Fusuo; Christie, Peter; Yang, Jianchang; Huang, Jianliang; Guo, Shiwei; Shi, Xiaojun; Tang, Qiyuan; Peng, Jianwei; Zhong, Xuhua; Sun, Yixiang; Lv, Shihua; Jiang, Rongfeng; Dobermann, Achim

    2015-01-01

    Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG) emissions (N2O, CH4 and CO2-equivalent) with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices-BMPs) helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield). Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice system

  2. Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management.

    Directory of Open Access Journals (Sweden)

    Ning An

    Full Text Available Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG emissions (N2O, CH4 and CO2-equivalent with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices-BMPs helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield. Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice

  3. The accumulation of deleterious mutations in rice genomes: a hypothesis on the cost of domestication.

    Science.gov (United States)

    Lu, Jian; Tang, Tian; Tang, Hua; Huang, Jianzi; Shi, Suhua; Wu, Chung-I

    2006-03-01

    The extent of molecular differentiation between domesticated animals or plants and their wild relatives is postulated to be small. The availability of the complete genome sequences of two subspecies of the Asian rice, Oryza sativa (indica and japonica) and their wild relatives have provided an unprecedented opportunity to study divergence following domestication. We observed significantly more amino acid substitutions during rice domestication than can be expected from a comparison among wild species. This excess is disproportionately larger for the more radical kinds of amino acid changes (e.g. CysTyr). We estimate that approximately a quarter of the amino acid differences between rice cultivars are deleterious, not accountable by the relaxation of selective constraints. This excess is negatively correlated with the rate of recombination, suggesting that 'hitchhiking' has occurred. We hypothesize that during domestication artificial selection increased the frequency of many deleterious mutations.

  4. Variação diária da emissão de metano em solo cultivado com arroz irrigado no Sul do Brasil Diurnal variation of methane emission from a paddy field under rice cultivation in the Southern Brazil

    Directory of Open Access Journals (Sweden)

    Falberni de Souza Costa

    2008-10-01

    de arroz no Sul do Brasil (região litorânea e Sul do RS e região Sul de SC pelo fato destas apresentarem comportamento diário similar de radiação solar e de temperatura do ar. A adequação do procedimento deve ser confirmada para as demais sub-regiões produtoras do Sul do Brasil, mas principalmente para outras regiões que apresentem condições ambientais diversas.Methane (CH4 has a global warming potential 23 to 32 times higher than carbon dioxide and its emission rate in rice fields should vary daily with water and soil temperature, and plant metabolism. This study aimed to identify the appropriate time interval for air sampling in order to quantify the mean daily CH4 emission rate, key information to future studies aiming the derivation of regional indexes of CH4 emission. Three campaigns were performed to evaluate diurnal variation in CH4 emissions (3h interval from continuously flooded rice (Oryza sativa L. cv. 'IRGA-422 CL' fields at different crop stages (panicle differentiation and ripening and management systems (conventional tillage-CT and no-tillage-NT during 2002/2003 crop season in long-term experiment at the Instituto Rio Grandense do Arroz (IRGA, in Cachoeirinha, RS, Brazil. Static chamber method was used and the air samples collected with polystyrene syringes were analyzed by gas chromatography. Methane emission showed a same diurnal pattern in the three campaigns in the both tillage systems. The maximum range of emission (8-33mg CH4m-2 h-1 was observed in the early afternoon (12.00 to 15.00p.m. followed by a decline to a minimum around midnight to next morning (4-19mg CH4 m-2 h-1, in which fluxes were related to flood water temperature (campaign 1 and 3 or soil temperature (campaign 2. Taking into account the daily emission curves, plus operational aspects like chromatographic analysis of samples into the 24h period after air sampling, the time interval from 9.00 to 12.00a.m. is recommended to studies aiming to evaluate mean daily CH4

  5. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season

    Energy Technology Data Exchange (ETDEWEB)

    Pramanik, Prabhat, E-mail: prabhat2003@gmail.com; Haque, Md. Mozammel; Kim, Sang Yoon; Kim, Pil Joo, E-mail: pjkim@gnu.ac.kr

    2014-08-15

    Combination of leguminous and non-leguminous plant residues are preferably applied in rice paddy soils to increase the rate of organic matter mineralization and to improve plant growth. However, organic matter addition facilitates methane (CH{sub 4}) emission from rice paddy soil. Mineralization of organic nitrogen (N) increases NO{sub 3}–N concentrations in soil, which are precursors for the formation of nitrous oxide (N{sub 2}O). However, N{sub 2}O is a minor greenhouse gas emitted from submerged rice field and hence is not often considered during calculation of total global warming potential (GWP) during rice cultivation. The hypothesis of this study was that fluxes of N{sub 2}O emissions might be changed after removal of flooded water from rice field and the effect of cover crops on N{sub 2}O emissions in the fallow season might be interesting. However, the effects of N-rich plant residues on N{sub 2}O emission rates in the fallow season and its effect on annual GWP were not studied before. In this experiment, combination of barley (non-leguminous) and hairy vetch (leguminous) biomasses were applied at 9 Mg ha{sup −1} and 27 Mg ha{sup −1} rates in rice paddy soil. Cover crop application significantly increased CH{sub 4} emission flux while decreased N{sub 2}O emissions during rice cultivation. The lowest N{sub 2}O emission was observed in 27 Mg ha{sup −1} cover crop treated plots. Cover crop applications increased N contents in soil aggregates especially in smaller aggregates (< 250 μm), and that proportionately increased the N{sub 2}O emission potentials of these soil aggregates. Fluxes of N{sub 2}O emissions in the fallow season were influenced by the N{sub 2}O emission