Sample records for major rice ecosystems

  1. [Major domestication traits in Asian rice].

    PubMed

    Ou, Shu-Jun; Wang, Hong-Ru; Chu, Cheng-Cai

    2012-11-01

    Rice (Oryza sativa L.) is an excellent model plant in elucidation of cereal domestication. Loss of seed shattering, weakened dormancy, and changes in plant architecture were thought to be three key events in the rice domestication and creating the high-yield, uniform-germinating, and densely-planting modern rice. Loss of shattering is considered to be the direct morphological evidence for identifying domesticated rice. Two major shattering QTLs, Sh4 and qSH1, have displayed different domestication histories. Weakened seed dormancy is essential for synchronous germination in agricultural production. Genes Sdr4, qSD7-1, and qSD12 impose a global and complementary adaptation strategies in controlling seed dormancy. The prostate growth habit of wild rice is an adaptation to disturbed habitats, while the erect growth habit of rice cultivars meet the needs of compact planting, and such a plant architecture is mainly controlled by PROG1. The outcrossing habit of wild rice promotes propagation of domestication genes among different populations, while the self-pollinating habit of cultivated rice facilitates fixation of domestication genes. Currently, the researches on rice domestication mainly focus on individual genes or multiple neutral markers, and much less attention has been paid to the evolution of network controlling domestication traits. With the progress in functional genomics research, the molecular mechanism of domestication traits is emerging. Rice domestication researches based on network will be more comprehensive and better reflect rice domestica-tion process. Here, we reviewed most progresses in molecular mechanisms of rice domestication traits, in order to provide the new insights for rice domestication and molecular breeding. PMID:23208135

  2. [Behavior of HTO in simulated rice-water-soil ecosystem].

    PubMed

    Shi, Jianjun; Guo, Jiangfeng

    2003-02-01

    The behavior of transportation, accumulation and disappearance of HTO (tritium water) in a simulated rice-water-soil ecosystem was studied by using isotope-tracer techniques for simulated pollutants, and the fitting equation was confirmed by application of the open three-compartment system model and nonlinear regression method. The results showed that HTO in water was not only transferred to other compartments in the ecosystem, but also vaporized into atmosphere rapidly. Both free water tritium and bound tritium were found in the rice, and tritium of hygroscopic and crystalline water was consisted in the soil. The specific activity of free water tritium (or tritium of hygroscopic water) was stronger than that of bound tritium (or tritium of crystalline water). The specific activity of total tritium reduced after reaching the maximum in the rice and soil, and the bound tritium increased slowly. The specific activity of total tritium in stem was the strongest in the rice, and reached equipoise each other in the later stage gradually. The regression equations of accumulation and disappearance for the specific activity of total tritium in the water, soil and rice were given by analyzing the obtained data with exponential regression method. The analysis results of variance showed that each regression equation could describe the behavior of accumulation and disappearance of HTO in the rice-water-soil ecosystems preferably. PMID:12827885

  3. Behavior and Fate of C-DDE (1, 1-Dichloro-2, 2Bis (4-Chlorophenyl) Ethylene) in Rice Ecosystem

    Microsoft Academic Search

    S. T. Mehetre; S. P. Kale

    2008-01-01

    Behavior of C-DDE (1, 1-dichloro-2, 2-bis (4-Chlorophenyl) Ethylene), a major degradation product of DDT (1, 1, 1-tricholoro-2, 2-bis (p-chlorophenyl) ethane), was studied in a model rice ecosystem. Samples of rice plant, algae, soil and seed were collected at regular intervals and analyzed for DDE residues.C-DDE residues in water declined rapidly initially for the first 8 days and then gradually for

  4. Transgenic Bacillus thuringiensis (Bt) Rice Is Safer to Aquatic Ecosystems than Its Non-Transgenic Counterpart

    PubMed Central

    Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

    2014-01-01

    Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt) significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems. PMID:25105299

  5. Major flood disturbance alters river ecosystem evolution

    NASA Astrophysics Data System (ADS)

    Milner, Alexander M.; Robertson, Anne L.; McDermott, Michael J.; Klaar, Megan J.; Brown, Lee E.

    2013-02-01

    Floods, major formative drivers of channel and floodplain structure and associated riparian and in-stream communities, are increasing in intensity and magnitude with climate change in many regions of the world. However, predicting how floods will affect stream channels and their communities as climate changes is limited by a lack of long-term pre-flood baseline data sets across different organismal groups. Here we show salmon, macroinvertebrate and meiofauna communities, monitored for 30 years in a system evolving owing to glacier retreat, were modified significantly by a major rainfall event that caused substantial geomorphic change to the stream channel. Pink salmon, reduced to one-tenth of pre-flood spawner densities, recovered within two generations. Macroinvertebrate community structure was significantly different after the flood as some pioneer taxa, which had become locally extinct, recolonized whereas some later colonizers were eliminated. The trajectory of the macroinvertebrate succession was reset towards the community structure of 15 years earlier. Meiofaunal abundance recovered rapidly and richness increased post-flood with some previously unrecorded taxa colonizing. Biotic recovery was independent of geomorphological recovery. Markedly different responses according to the organismal group suggest caution is required when applying general aquatic ecosystem theories and concepts to predict flood events.

  6. STRAW MANAGEMENT AFFECTING METHANE EMISSIONS FROM DIFFERENT RICE ECOSYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emissions of the greenhouse gas methane from wetland rice fields are generally enhanced by organic inputs into the soil. This study investigates methane emissions and crop residue management at three sites: Los Banos (Philippines), Hangzhou (China), and Prachinburi (Thailand). In Los Banos, the co...

  7. Study of mosquito fauna in rice ecosystems around Hanoi, northern Vietnam.

    PubMed

    Ohba, Shin-ya; Van Soai, Nguyen; Van Anh, Dinh Thi; Nguyen, Yen T; Takagi, Masahiro

    2015-02-01

    Species of the Culex vishnui subgroup, Cx. fuscocephala and Cx. gelidus, which are known Japanese encephalitis (JE) vectors, are distributed in rice agroecosystems in Asian countries. Hence, although ecological studies of rice agroecosystems in northern Vietnam are necessary, very few integrated studies of breeding habitats of mosquitoes, including JE vectors, have been conducted. We carried out a field study and investigated the mosquito fauna in six rice production areas in northern Vietnam during the rainy and dry seasons of 2009. Mosquitoes and potential mosquito predators were collected from aquatic habitats by using larval dippers. We collected 1780 Culex individuals (including 254 Cx. tritaeniorhynchus; 113 Cx. vishnui, 58 Cx. vishnui complex, consisting of Cx. vishnui and Cx. pseudovishnui; 12 Cx. gelidus; 1 Cx. bitaeniorhynchus; and 1 Cx. fuscocephala), 148 Anopheles individuals (including 5 An. vagus), 1 Mansonia annulifera, and 1 Mimomyia chamberlaini during the rainy season. During the dry season, we collected 176 Culex individuals (including 33 Cx. vishnui, 24 Cx. tritaeniorhynchus, 8 Cx. vishnui complex, and 1 Cx. gelidus) and 186 Anopheles individuals (including 9 An. tessellatus, 2 An. kochi, and 2 An. barbumbrosus). We found mosquitoes in all aquatic habitats, namely, rice fields, ditches, ponds, wetlands, irrigation canals, and rice nurseries, and Cx. tritaeniorhynchus and Cx. vishnui complex were found in all the above six areas. Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both the seasons. The abundance of mosquito larvae was higher in the rice fields, ditches, and ponds during the rainy season than during the dry season. Cx. tritaeniorhynchus, Cx. vishnui complex, Cx. fuscocephala, and Cx. gelidus were abundant in rice agroecosystems (rice fields, ditches, ponds, and wetlands) in northern Vietnam, and their abundance was high during the rainy season. These findings deepen our understanding of mosquito ecology and strengthen mosquito control strategies to be applied in rice ecosystems Vietnam in the future. PMID:25445747

  8. Differences in CH4 and N2O emissions between rice nurseries in Chinese major rice cropping areas

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Li, Zhijie; Feng, Jinfei; Zhang, Xin; Jiang, Yu; Chen, Jin; Zhang, Mingqian; Deng, Aixing; Zhang, Weijian

    2014-10-01

    Studies on greenhouse gas (GHG) emissions from paddy field have primarily focused on the post-transplanting period, however, recent researches raise new concerns about GHGs emission from rice nursery. In this study, CH4 and N2O fluxes were determined from different nurseries under major rice cropping systems in China. The tested nurseries included flooded nursery (FN), moist nursery (MN) and dry nursery (DN). Methane emissions from FN were significantly higher than those from MN and DN under all the rice cropping systems. When comparing with FN, MN decreased total CH4 emissions by 74.2%, 72.1% and 49.6% under the rice-upland rotation cropping system (RUR), and the double rice cropping system for the early rice (EDR) and the late rice (LDR), respectively. DN decreased CH4 emissions by 99.2%, 92.0%, 99.0% and 78.6% compared to FN under the single rice cropping system (SR), RUR, EDR and LDR, respectively. When comparing with FN, MN and DN increased N2O emissions by 58.1-134.1% and 28.2-332.7%, respectively. Ultimately, compared with FN across the cropping systems, MN and DN decreased net global warming potentials (GWPs) of CH4 and N2O by 33-68% and 43-86%, respectively. The mitigating effect of MN and DN on total GWPs varied greatly across the systems, ranging from 30.8% in the LDR to 86.5% in the SR. Chinese actual emission from rice nurseries was reduced to 956.66 × 103 t CO2 eq from the theoretical estimate of 2242.59 × 103 t CO2 eq if under the flooded nursery scenario in 2012. Taking into account the large rice nursery area (2032.52 × 103 ha) in China, the results of this study clearly indicate the importance to estimate and mitigate GHGs emission from flooded rice nursery. Being effective to reduce GHG emissions and increase rice yield, dry nursery technique is a promising candidate for climate smart rice cropping.

  9. Water infiltration studies of the major rice producing soil series of the Texas Gulf Coast

    E-print Network

    Nesmith, Douglas M

    1988-01-01

    WATER INFILTRATION STUDIES OF THE MAJOR RICE PRODUCING SOIL SERIES OF THE TEXAS GULF COAST A Thesis by DOUGLAS MICHAEL NESMITH Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1988 Major Subject: Soil Science MATER INFILTRATION STUDIES OF THE MAJOR RICE PRODUCING SOIL SERIES OF THE TEXAS GULF COAST A Thesis by DOUGLAS MICHAEL NESMITH Approved as to style and content by: L. Lloyd R. Hossner...

  10. Degradation kinetics of the insecticide spinetoram in a rice field ecosystem.

    PubMed

    Zhao, Li; Chen, Guo; Zhao, Jian; Zhang, Yan; Zhu, Yong; Yang, Ting; Wu, Yin-Liang

    2015-01-01

    The fate of spinetoram was studied in a rice field ecosystem, and an efficient method for the determination of spinetoram (XDE-175-J and XDE-175-L) in soil, rice straw, paddy water, husk and brown rice was developed. Spinetoram residues were extracted from samples with a salting out extraction procedure. The extracts were diluted with 0.10% formic acid in water and analysed with liquid chromatography tandem mass spectrometry (LC-MS/MS) on a Waters Acquity BEH C18 column. The calibration curve was linear in the range 0.125-100 ?g L(-1) and r>0.999. The average recovery was 82.9-89.0% from soil, 78.5-92.1% from rice straw, 93.6-100.3% from paddy water, 79.1-87.9% from brown rice and 72.7-82.9% from husk. The relative standard deviation (RSD) was less than 10%. These results are all within the accepted range for pesticide residue determination. The field test results showed that spinetoram degradation in paddy water, soil and rice straw coincided with C=0.0132e(-1.9685t), C=0.0308e(-0.1018t) and C=0.8530e(-0.6223t), respectively. The half-lives of spinetoram in paddy water, soil and rice straw were 0.35, 6.8 and 1.1 d, respectively. The final residue level was lower than the maximum residue limit (MRL) of 0.05 mg kg(-1) for spinetoram in rice with a harvest interval of 7d. A dosage of 450 mL ha(-1) was recommended, which can be considered safe for human beings and animals. The results of this study will contribute to establishing the scientific basis of the dosage of spinetoram for agricultural fields. PMID:25460760

  11. Exploring the Ecological Significance of Microbial Diversity and Networking in the Rice Ecosystem

    Microsoft Academic Search

    Radha Prasanna; Lata Nain; Alok Kumar Pandey; Saswati Nayak

    \\u000a Rice fields represent “hot spots of biodiversity” – encompassing a complicated network of aerobic, anaerobic and facultative\\u000a micro-organisms, whose interactions with the resident macro flora and fauna lead to unique and complex biochemical and physicochemical\\u000a reactions. In turn, these reactions fuel the major nutrient cycles. The dynamics of microbiological activity of rice soil,\\u000a especially in the rhizosphere, represents a model

  12. Rice is the staple food source of nutrients for both humans and livestock throughout the world. The major proteins in rice seeds

    E-print Network

    Collins, Gary S.

    Rice is the staple food source of nutrients for both humans and livestock throughout the world. The major proteins in rice seeds are the storage proteins, glutelins and prolamins. Their m effector proteins in rice developing seed extracts. The eluted proteins from the positive and negative Rab5

  13. Isolation and initial characterization of GW5, a major QTL associated with rice grain width and weight

    Microsoft Academic Search

    Jianfeng Weng; Suhai Gu; Xiangyuan Wan; He Gao; Tao Guo; Ning Su; Cailin Lei; Xin Zhang; Zhijun Cheng; Xiuping Guo; Jiulin Wang; Ling Jiang; Huqu Zhai; Jianmin Wan

    2008-01-01

    Grain weight is a major determinant of crop grain yield and is controlled by naturally occurring quantitative trait loci (QTLs). We earlier identified a major QTL that controls rice grain width and weight, GW5, which was mapped to a recombination hotspot on rice chromosome 5. To gain a better understanding of how GW5 controls rice grain width, we conducted fine

  14. Track of fate and primary metabolism of trifloxystrobin in rice paddy ecosystem.

    PubMed

    Cao, Mengchao; Li, Shuying; Wang, Quansheng; Wei, Peng; Liu, Yanan; Zhu, Guonian; Wang, Mengcen

    2015-06-15

    Trifloxystrobin, a strobilurin fungicide, has been widely applied to control fungal diseases in various crops, especially in rice cultivation. However, its residual profile in rice paddy that was highly linked to its ecological risk still remains poorly understood. To elucidate the fate and primary metabolism of trifloxystrobin in rice paddy, a simple and efficient analytical method was developed using the DisQuE extraction kit combined with GC-?ECD and GC-EI-MS/MS analyses. As a result, methodological recoveries of trifloxystrobin fortified in paddy water, soil and rice straw ranging from 0.005 to 2mgkg(-1) (mgL(-1) for water) were acquired from 87.6% to 109.1% with relative standard deviation (RSD) from 1.9% to 9.5% (n=5), and the limit of detection (LOD, signal to noise (S/N)=3) and the limit of quantification (LOQ, S/N=10) were 6.3×10(-4)mgL(-1) and 2.09×10(-3)mgL(-1), respectively, which indicates the favorable accuracy, precision and sensitivity of the method for effective monitoring of the trace amounts of residual trifloxystrobin in the rice paddy. Furthermore, dissipation of residual trifloxystrobin was in accordance with the first-order rate equation, showing the half-lives from 0.7 to 7.5days, illustrating that trifloxystrobin generally degraded in a rapid rate in the rice paddy. Additionally, trifloxystrobin acid identified as the primary metabolite of trifloxystrobin in the rice paddy via GC-EI-MS/MS analysis was found to be dominantly accumulated in the paddy water and maintained up to 2.41mgL(-1) within 14days, suggesting that long-term and frequent application of this fungicide may pose a high risk towards aquatic organisms in surrounding aqueous ecosystems through paddy drainage. Taken together, our data serve as a useful tool for monitoring residual trifloxystrobin in rice paddy ecosystem and also provide a basis for in-depth understanding of environmental behavior and ecological risk posed by this fungicide. PMID:25770954

  15. Identification of major rice allergen and their clinical significance in children

    PubMed Central

    Jeon, You Hoon; Oh, Se Jo; Yang, Hyeon Jong; Lee, Soo Young

    2011-01-01

    Purpose Recently, an increase in the number of patients sensitized to rice allergen with or without clinical symptoms has been reported. This study was designed to determine the major allergens in rice and their clinical significance. Methods Twenty-four children (15 boys and 9 girls; mean age, 16.3 months) with allergic disease, who were sensitized to rice antigen (by UniCAP) in the Pediatric Allergy Respiratory Center at Soonchunhyang University Hospital, were enrolled in this study. The allergenicity of various types of rice (raw, cooked, and heat-treated, simulated gastric fluid [SGF], and simulated intestinal fluid [SIF]) was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoglobulin E (IgE) immunoblots. The patients' medical records, including laboratory data and allergy symptoms after ingestion of rice were reviewed. Results Patients were sensitized to an average of 13.5 food antigens and their mean total IgE was 6,888.7 kU/L. In SDS-PAGE, more than 16 protein bands were observed in the raw rice, whereas only 14-16 kDa and 31-35 kDa protein bands were observed in cooked rice. The common SDS-PAGE protein bands observed in SGF-, SIF-, and heat-treated rice were 9, 14, and 31 kDa. In a heated-rice IgE immunoblot, protein bands of 9, 14, and 31-33 kDa were found in 27.8%, 38.9%, and 38.9% of all sera, respectively, and in 50%, 50%, and 75%, of ser a from the 4 symptomatic patients, respectively. Conclusion The 9-, 14-, and 31-kDa protein bands appeared to be the major allergens responsible for rice allergy symptoms. PMID:22232624

  16. Genetic, physiological and molecular interactions of rice and its major dipteran pest, gall midge

    Microsoft Academic Search

    Nagesh Sardesai; K. R. Rajyashri; S. K. Behura; Suresh Nair; Madan Mohan

    2001-01-01

    The gall midge, Orseolia oryzae, is a major dipteran pest of rice affecting most rice growing regions in Asia, Southeast Asia and Africa. Chemical and other\\u000a cultural methods for control of this pest are neither very effective nor environmentally safe. The gall midge problem is further\\u000a compounded by the fact that there are many biotypes of this insect and new

  17. Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus

    PubMed Central

    Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, César P.; Calvert, Lee; Lorieux, Mathias

    2013-01-01

    Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

  18. Major QTLs control resistance to rice hoja blanca virus and its vector Tagosodes orizicolus.

    PubMed

    Romero, Luz E; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C; Martinez, César P; Calvert, Lee; Lorieux, Mathias

    2014-01-01

    Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

  19. A putative acyl-CoA-binding protein is a major phloem sap protein in rice (Oryza sativa L.)

    Microsoft Academic Search

    Nobuo Suzui; Shin-ichi Nakamura; Toru Fujiwara; Hiroaki Hayashi; Tadakatsu Yoneyama

    2006-01-01

    The N-terminal amino-acid sequence of a major rice phloem-sap protein, named RPP10, was determined. RPP10 is encoded by a single gene in the rice genome. Its complete amino-acid sequence, predicted from the corresponding rice full-length cDNA, showed high similarity to plant acyl-CoA-binding proteins (ACBPs). Western blot analysis using anti-ACBP antiserum re- vealed that putative ACBP is abundant in the phloem

  20. Days to heading 7, a major quantitative locus determining photoperiod sensitivity and regional adaptation in rice

    PubMed Central

    Gao, He; Jin, Mingna; Zheng, Xiao-Ming; Chen, Jun; Yuan, Dingyang; Xin, Yeyun; Wang, Maoqing; Huang, Dongyi; Zhang, Zhe; Zhou, Kunneng; Sheng, Peike; Ma, Jin; Ma, Weiwei; Deng, Huafeng; Jiang, Ling; Liu, Shijia; Wang, Haiyang; Wu, Chuanyin; Yuan, Longping; Wan, Jianmin

    2014-01-01

    Success of modern agriculture relies heavily on breeding of crops with maximal regional adaptability and yield potentials. A major limiting factor for crop cultivation is their flowering time, which is strongly regulated by day length (photoperiod) and temperature. Here we report identification and characterization of Days to heading 7 (DTH7), a major genetic locus underlying photoperiod sensitivity and grain yield in rice. Map-based cloning reveals that DTH7 encodes a pseudo-response regulator protein and its expression is regulated by photoperiod. We show that in long days DTH7 acts downstream of the photoreceptor phytochrome B to repress the expression of Ehd1, an up-regulator of the “florigen” genes (Hd3a and RFT1), leading to delayed flowering. Further, we find that haplotype combinations of DTH7 with Grain number, plant height, and heading date 7 (Ghd7) and DTH8 correlate well with the heading date and grain yield of rice under different photoperiod conditions. Our data provide not only a macroscopic view of the genetic control of photoperiod sensitivity in rice but also a foundation for breeding of rice cultivars better adapted to the target environments using rational design. PMID:25378698

  1. Days to heading 7, a major quantitative locus determining photoperiod sensitivity and regional adaptation in rice.

    PubMed

    Gao, He; Jin, Mingna; Zheng, Xiao-Ming; Chen, Jun; Yuan, Dingyang; Xin, Yeyun; Wang, Maoqing; Huang, Dongyi; Zhang, Zhe; Zhou, Kunneng; Sheng, Peike; Ma, Jin; Ma, Weiwei; Deng, Huafeng; Jiang, Ling; Liu, Shijia; Wang, Haiyang; Wu, Chuanyin; Yuan, Longping; Wan, Jianmin

    2014-11-18

    Success of modern agriculture relies heavily on breeding of crops with maximal regional adaptability and yield potentials. A major limiting factor for crop cultivation is their flowering time, which is strongly regulated by day length (photoperiod) and temperature. Here we report identification and characterization of Days to heading 7 (DTH7), a major genetic locus underlying photoperiod sensitivity and grain yield in rice. Map-based cloning reveals that DTH7 encodes a pseudo-response regulator protein and its expression is regulated by photoperiod. We show that in long days DTH7 acts downstream of the photoreceptor phytochrome B to repress the expression of Ehd1, an up-regulator of the "florigen" genes (Hd3a and RFT1), leading to delayed flowering. Further, we find that haplotype combinations of DTH7 with Grain number, plant height, and heading date 7 (Ghd7) and DTH8 correlate well with the heading date and grain yield of rice under different photoperiod conditions. Our data provide not only a macroscopic view of the genetic control of photoperiod sensitivity in rice but also a foundation for breeding of rice cultivars better adapted to the target environments using rational design. PMID:25378698

  2. Genetic variation in root morphology and microsatellite DNA loci in upland rice (Oryza sativa L.) from Vietnam

    Microsoft Academic Search

    N. D. Thanh; H. G. Zheng; N. V. Dong; L. N. Trinh; M. L. Ali; H. T. Nguyen

    1999-01-01

    Drought is a major constraint to the productivity of rice in upland ecosystems. The rice root system plays an important role in the regulation of water uptake and extraction from deep soil layers. The aim of this research was to study the variation in root morphology and the genetic diversity in upland rice accessions. Thirty-three upland rice accessions originated from

  3. Major and Trace Elements in Rice Seeds from Ko~ani Field, Macedonia

    Microsoft Academic Search

    Nastja Rogan; Tadej Dolenec; Todor Serafimovski

    The objective of this study was to assess the total concentrations of selected major and trace elements in rice seeds from Ko~ani Field impacted by heavy metals due to irrigation with riverine water affected by acid mine drainage and other mining activities of the Zletovo-Kratovo and Sasa-Toranica Pb-Zn ore districts. The analytical results obtained with the k0-instrumental neutron-activation analysis (k0-INAA)

  4. Development and application of gene-based markers for the major rice QTL Phosphorus uptake 1.

    PubMed

    Chin, Joong Hyoun; Lu, Xiaochun; Haefele, Stephan M; Gamuyao, Rico; Ismail, Abdelbagi; Wissuwa, Matthias; Heuer, Sigrid

    2010-04-01

    Marker-assisted breeding is a very useful tool for breeders but still lags behind its potential because information on the effect of quantitative trait loci (QTLs) in different genetic backgrounds and ideal molecular markers are unavailable. Here, we report on some first steps toward the validation and application of the major rice QTL Phosphate uptake 1 (Pup1) that confers tolerance of phosphorus (P) deficiency in rice (Oryza sativa L.). Based on the Pup1 genomic sequence of the tolerant donor variety Kasalath that recently became available, markers were designed that target (1) putative genes that are partially conserved in the Nipponbare reference genome and (2) Kasalath-specific genes that are located in a large insertion-deletion (INDEL) region that is absent in Nipponbare. Testing these markers in 159 diverse rice accessions confirmed their diagnostic value across genotypes and showed that Pup1 is present in more than 50% of rice accessions adapted to stress-prone environments, whereas it was detected in only about 10% of the analyzed irrigated/lowland varieties. Furthermore, the Pup1 locus was detected in more than 80% of the analyzed drought-tolerant rice breeding lines, suggesting that breeders are unknowingly selecting for Pup1. A hydroponics experiment revealed genotypic differences in the response to P deficiency between upland and irrigated varieties but confirmed that root elongation is independent of Pup1. Contrasting Pup1 near-isogenic lines (NILs) were subsequently grown in two different P-deficient soils and environments. Under the applied aerobic growth conditions, NILs with the Pup1 locus maintained significantly higher grain weight plant(-1) under P deprivation in comparison with intolerant sister lines without Pup1. Overall, the data provide evidence that Pup1 has the potential to improve yield in P-deficient and/or drought-prone environments and in diverse genetic backgrounds. PMID:20035315

  5. Whole-genome quantitative trait locus mapping reveals major role of epistasis on yield of rice.

    PubMed

    Huang, Anhui; Xu, Shizhong; Cai, Xiaodong

    2014-01-01

    Although rice yield has been doubled in most parts of the world since 1960s, thanks to the advancements in breeding technologies, the biological mechanisms controlling yield are largely unknown. To understand the genetic basis of rice yield, a number of quantitative trait locus (QTL) mapping studies have been carried out, but whole-genome QTL mapping incorporating all interaction effects is still lacking. In this paper, we exploited whole-genome markers of an immortalized F2 population derived from an elite rice hybrid to perform QTL mapping for rice yield characterized by yield per plant and three yield component traits. Our QTL model includes additive and dominance main effects of 1,619 markers and all pair-wise interactions, with a total of more than 5 million possible effects. The QTL mapping identified 54, 5, 28 and 4 significant effects involving 103, 9, 52 and 7 QTLs for the four traits, namely the number of panicles per plant, the number of grains per panicle, grain weight, and yield per plant. Most identified QTLs are involved in digenic interactions. An extensive literature survey of experimentally characterized genes related to crop yield shows that 19 of 54 effects, 4 of 5 effects, 12 of 28 effects and 2 of 4 effects for the four traits, respectively, involve at least one QTL that locates within 2 cM distance to at least one yield-related gene. This study not only reveals the major role of epistasis influencing rice yield, but also provides a set of candidate genetic loci for further experimental investigation. PMID:24489897

  6. Differences among Major Taxa in the Extent of Ecological Knowledge across Four Major Ecosystems

    PubMed Central

    Fisher, Rebecca; Knowlton, Nancy; Brainard, Russell E.; Caley, M. Julian

    2011-01-01

    Existing knowledge shapes our understanding of ecosystems and is critical for ecosystem-based management of the world's natural resources. Typically this knowledge is biased among taxa, with some taxa far better studied than others, but the extent of this bias is poorly known. In conjunction with the publically available World Registry of Marine Species database (WoRMS) and one of the world's premier electronic scientific literature databases (Web of Science®), a text mining approach is used to examine the distribution of existing ecological knowledge among taxa in coral reef, mangrove, seagrass and kelp bed ecosystems. We found that for each of these ecosystems, most research has been limited to a few groups of organisms. While this bias clearly reflects the perceived importance of some taxa as commercially or ecologically valuable, the relative lack of research of other taxonomic groups highlights the problem that some key taxa and associated ecosystem processes they affect may be poorly understood or completely ignored. The approach outlined here could be applied to any type of ecosystem for analyzing previous research effort and identifying knowledge gaps in order to improve ecosystem-based conservation and management. PMID:22073172

  7. Rice Ratooning Management Practices for Higher Yields

    Microsoft Academic Search

    A. B. Santos; N. K. Fageria; A. S. Prabhu

    2003-01-01

    Rice is one of the world's most important cereal crops and rice ratooning is one of the potential technologies to increase rice production. Based on land and water management, rice ecosystem is mainly divided into lowland, upland and deep water or floating rice. Rice ratooning is mainly practiced on lowland rice ecosystem. Ratooning provides higher resource use efficiency per unit

  8. Antioxidant activities of major components of ?-oryzanol from rice bran using a linoleic acid model

    Microsoft Academic Search

    Zhimin Xu; J. Samuel Godber

    2001-01-01

    The change in hydroperoxides of linoleic acid incubated with constant micro air flow at 37°C was used to evaluate the antioxidant\\u000a activities of three major components of ?-oryzanol from rice bran (cycloartenyl ferulate, 24-methylene cycloartanyl ferulate,\\u000a and campesteryl ferulate) compared with ?-tocopherol and ferulic acid. The four hydroperoxide isomers of linoleic acid, 9-hydroperoxy-10-trans, 12-cis-octadecadienoic acid [9HPODE(t,c)], 9-hydroperoxy-10-trans, 12-trans-octadecadienoic acid, 13-hydroperoxy-9-cis,

  9. Arsenic concentrations in paddy soil and rice and health implications for major rice-growing regions of Cambodia.

    PubMed

    Seyfferth, Angelia L; McCurdy, Sarah; Schaefer, Michael V; Fendorf, Scott

    2014-05-01

    Despite the global importance of As in rice, research has primarily focused on Bangladesh, India, China, and the United States with limited attention given to other countries. Owing to both indigenous As within the soil and the possible increases arising from the onset of irrigation with groundwater, an assessment of As in rice within Cambodia is needed, which offers a "base-case" comparison against sediments of similar origin that comprise rice paddy soils where As-contaminated water is used for irrigation (e.g., Bangladesh). Here, we evaluated the As content of rice from five provinces (Kandal, Prey Veng, Battambang, Banteay Meanchey, and Kampong Thom) in the rice-growing regions of Cambodia and coupled that data to soil-chemical factors based on extractions of paddy soil collected and processed under anoxic conditions. At total soil As concentrations ranging 0.8 to 18 ?g g(-1), total grain As concentrations averaged 0.2 ?g g(-1) and ranged from 0.1 to 0.37 with Banteay Meanchey rice having significantly higher values than Prey Veng rice. Overall, soil-extractable concentrations of As, Fe, P, and Si and total As were poor predictors of grain As concentrations. While biogeochemical factors leading to reduction of As(V)-bearing Fe(III) oxides are likely most important for predicting plant-available As, husk and straw As concentrations were the most significant predictors of grain-As levels among our measured parameters. PMID:24712677

  10. [Controlling effects of multiple species coexistence on rice diseases, pests and weeds in paddy field ecosystem].

    PubMed

    Wang, Han; Tang, Jian-jun; Xie, Jian; Chen, Xin

    2007-05-01

    Establishing a species-diversified cropping system to control crop diseases, insect pests and weeds is an important approach to sustainable agricultural development. This paper reviewed the researches on paddy field species-diversified cropping systems at home and abroad, and discussed the controlling effects and mechanisms of multiple species coexistence on rice diseases, pests and weeds control. The multiple species coexistence models such as rice-fish, rice-duck, rice-azolla-fish and rice-azolla-duck had effective controlling effects on Thanatephorus cucumeris (Frank) Donk, Nilaparata lugens Stal, Chaphalocrocis medinalis Gueneeand, and weeds. Other models like intercropping rice with Zizania caduciflora L. and with other wetland crops also had effective effects in controlling the occurrence and spread of Pyricularia grisea. It was suggested that further studies should be strengthened from the viewpoints of crop culture, molecular biology, and chemical ecolo- PMID:17650871

  11. Diversity of Gram negative bacteria antagonistic against major pathogens of rice from rice seed in the tropic environment.

    PubMed

    Xie, Guan-Lin; Soad, Algam; Swings, J; Mew, T W

    2003-01-01

    With the use of a seed washing technique, more than 4000 Gram negative bacteria were isolated by two improved isolation methods from 446 batches of 1 kg rice seed samples obtained from 22 provinces in the Philippines. They were initially characterized on the basis of colony morphology and results of biochemical and pathogenicity tests. Six hundred and fifty-two strains were further identified by Biolog, from which 133 were selected for fatty acid methylester (FAME) analysis together with 80 standard reference strains. Sixteen species or types of Pseudomonas and 17 genera of non-pseudomonads were identified, more than one third of which have not been recorded in rice. The most predominant species observed were P.putida and P. fulva. About 17% of the strains of Pseudomonas and 2% of the non pseudomonads were antagonistic to one or more fungal or bacterial pathogens of rice. Rice seed is an important source of biological control agents. PMID:12861624

  12. Net ecosystem exchange, gross primary production, and ecosystem respiration of carbon dioxide during barley growing season in rice-barley paddy field of Korea

    NASA Astrophysics Data System (ADS)

    Jung, M.; Shim, K.; Min, S.; Kim, Y.; Kim, S.; So, K.

    2013-12-01

    This study was conducted to measure carbon dioxide exchange between customarily cultivated rice-barley double cropping paddy field and the atmosphere during barley growing season (October 2012 and June 2013) and to estimate carbon dioxide fluxes using agro-meteorological factors (temperature, net radiation etc. ) and barley biomass. The carbon dioxide fluxes were quantified by eddy covariance technique in paddy fields with rice-barley double cropping system, located at the Gimje flux site in the southwestern coast of Korea. The total values of net ecosystem carbon dioxide exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) were -100.6, 782.7, and 682.5 g C m-2 during barley growing season, respectively. The NEE was tended to keep between 0 and 5 g C m-2 d-1 from sowing date (Oct. 21, 2012) to winter rest stage (Dec. 3, 2012 to Feb. 22, 2013), and gradually decreased in tillering stage (Feb. 23, 2013 to May 5, 2013) with its maximum around heading date, and then started to increase in ripening stage (May 6, 2013 to Jun. 8, 2013). The soil temperature was strongly correlated with the Re (r2=0.86), while the net radiation showed the weak relationship with the GPP during the emergence, seedling, and winter rest stage. The aboveground biomass of barley was significantly correlated with the values of NEE (r2=0.79), GPP (r2=0.83), and Re (r2=0.77), respectively.

  13. A putative acyl-CoA-binding protein is a major phloem sap protein in rice (Oryza sativa L.).

    PubMed

    Suzui, Nobuo; Nakamura, Shin-ichi; Fujiwara, Toru; Hayashi, Hiroaki; Yoneyama, Tadakatsu

    2006-01-01

    The N-terminal amino-acid sequence of a major rice phloem-sap protein, named RPP10, was determined. RPP10 is encoded by a single gene in the rice genome. Its complete amino-acid sequence, predicted from the corresponding rice full-length cDNA, showed high similarity to plant acyl-CoA-binding proteins (ACBPs). Western blot analysis using anti-ACBP antiserum revealed that putative ACBP is abundant in the phloem sap of rice plants, and is also present in sieve-tube exudates of winter squash (Cucurbita maxima), oilseed rape (Brassica napus), and coconut palm (Cocos nucifera). These findings give rise to the idea that ACBP may involve lipid metabolism and regulation in the phloem. PMID:16804052

  14. In situ immunogold labeling analysis of the rice hoja blanca virus nucleoprotein and major noncapsid protein.

    PubMed

    Espinoza, A M; Hernández, M; Pereira, R; Falk, B; Medina, V

    1992-12-01

    Ribonucleoprotein particles (RNPs) of rice hoja blanca virus (RHBV) were purified and used for electron microscopic analysis and antibody production. Antibodies made to RNPs specifically decorated purified RNPs. The RNPs typically showed characteristic tenuivirus morphologies. They were approximately 8 nm in diameter, mostly circular in nature, and exhibited branching and a high degree of superhelicity. When the RNP antibodies were used for in situ immunogold labeling analysis of RHBV-infected tissues, no specific structures were identified, but gold particles were distributed throughout the cytosol of RHBV-infected but not healthy plants. However, amorphous semi-electron opaque inclusion bodies (ASO-IBs) were abundant in cells of RHBV-infected plants. While the ASO-IBs were not labeled with the anti-RNP antiserum, they were specifically labeled with antibodies to the RHBV major noncapsid protein (NCP) and with antibodies to the NCP of another tenuivirus, maize stripe virus. PMID:1448918

  15. Determination and study on dissipation and residue determination of cyhalofop-butyl and its metabolite using HPLC-MS/MS in a rice ecosystem.

    PubMed

    Wu, Junxue; Wang, Kai; Zhang, Yun; Zhang, Hongyan

    2014-10-01

    Cyhalofop-butyl is an aryloxyphenoxypropionate postemergence herbicide with good control of barnyard grass in rice paddies. In this study, method for the determination of cyhalofop-butyl and its metabolite was developed with high-performance liquid chromatography tandem mass spectrometry. Dissipation and residue levels of cyhalofop-butyl and its metabolite in rice ecosystems were also investigated. Recoveries and relative standard deviations of cyhalofop-butyl and cyhalofop acid in six matrices at three spiking levels ranged from 76.1 to 107.5% and 1.1 to 8.2%, respectively. The limit of quantitation (LOQ) of cyhalofop-butyl and cyhalofop acid was 0.01 mg/kg in paddy water, paddy soil, rice plant, rice straw, rice hulls, and husked rice. For field experiments, the results showed that cyhalofop-butyl degraded to cyhalofop acid quickly, and the half-lives of cyhalofop acid in paddy water, paddy soil, and rice plant were 1.01-1.53, 0.88-0.97, and 2.09-2.42 days, respectively. Ultimate residues of cyhalofop-butyl and its metabolite in the rice samples were not detectable or below 0.01 mg/kg at harvest. PMID:25007772

  16. Assessment of toxicity risk of insecticides used in rice ecosystem on Trichogramma japonicum, an egg parasitoid of rice lepidopterans.

    PubMed

    Zhao, Xueping; Wu, Changxing; Wang, Yanhua; Cang, Tao; Chen, Liping; Yu, Ruixian; Wang, Qiang

    2012-02-01

    Both chemical and biological methods are essential for control of insects, for example, lepidopterans, on rice. Thus, it is important to know the effect of chemicals on the biological control agents. In this study, we assessed the toxicity of commonly used insecticides on a biological control agent, Trichogramma japonicum Ahmead (an egg parasitoid of rice lepidopterans) by using a dry film residue method. Results showed that thirty insecticides from seven chemical classes exhibited various degree of toxicity to this parasitoid. Among the seven classes of chemicals tested, organophosphates (chlorpyrifos, fenitrothion, phoxim, profenofos, and triazophos) and carbamates (carbaryl, carbsulfan, isoprocarb, metolcarb, and promecarb) exhibited the highest intrinsic toxicity to T. japponicum, with an LC50 of 0.035 (0.029-0.044) to 0.49 (0.34-0.87) mg active ingredient (a.i.) L(-1), followed by antibiotics (abamectin, emamectin benzoate, and ivermectin), phenylpyrazoles (butane-fipronil, ethiprole, and fipronil), pyrethroids (cyhalthrin, cypermethrin, fenpropathrin, and lambda-cyhaothrin), and neonicotinoids (acetamiprid, imidacloprid, imidaclothiz, nitenpyram, thiacloprid, and thiamethoxam). Moreover, the insect growth regulator insecticides (chlorfluazuron, fufenozide, hexaflumuron and tebufenozide) exhibited the lowest toxicity to the wasps with an LC50 of 3,383 (2406-5499) to 30206 (23107-41008) mg ai. L(-1). Risk quotient analysis showed that phenylpyrazoles, pyrethroids, insect growth regulators, neonicotinoids (with the exception of thiamethoxam), and antibiotics (with the exception of abamectin) are classified as safe agents to the parasitoid, while organophosphates and carbamates are classified as slightly, moderately, or highly toxic agents to the parasitoid. The data presented in this paper provided useful information on the selection of compatible insecticides with T. japonicum. PMID:22420260

  17. Fine mapping of a major QTL controlling panicle number in rice

    Microsoft Academic Search

    Jinyan ZhuYong; Yong Zhou; Yanhua Liu; Zhongde Wang; Zaixiang Tang; Chuandeng Yi; Shuzhu Tang; Minghong Gu; Guohua Liang

    2011-01-01

    Rice panicle number per plant is a grain yield component that directly influences rice yield. The identification of the genes\\u000a controlling panicle number will play a vital role in high-yield rice breeding. C3074, a chromosome segment substitution line\\u000a containing an introgression segment of Nipponbare in the genetic background of Guangluai 4, had significantly fewer panicles.\\u000a Quantitative trait locus (QTL) analysis

  18. Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems

    Microsoft Academic Search

    Joann Burkholder; David Eggleston; Howard Glasgow; Cavell Brownie; Robert Reed; Gerald Janowitz; Martin Posey; Greg Melia; Carol Kinder; Reide Corbett; David Toms; Troy Alphin; Nora Deamer; Jeffrey Springer

    2004-01-01

    Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle-Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the

  19. Analysis of the spatial variation in the net ecosystem production of rice paddy fields using the diagnostic biosphere model BEAMS

    NASA Astrophysics Data System (ADS)

    Sasai, T.; Nakai, S.; Setoyama, Y.; Ono, K.; Kato, S.; Mano, M.; Miyata, A.; Saigusa, N.; Nemani, R. R.; Nasahara, K. N.

    2012-12-01

    To realistically understand spatial and temporal variations in the net ecosystem production (NEP) of rice paddies in Japan, we enhanced the existing diagnostic-type biosphere model with the addition of agricultural processes. Validated with a comparison of seasonal and annual variations over 5 years, the NEP estimations bore good agreement with the measurements. In regional-scale analyses, we targeted all rice paddy fields in Japan from January 2001 to December 2009. Before and after the model enhancement, the NEP showed very different spatial variations and absolute values, suggesting that the most effective improvements were the introduction of harvest and soil oxidation-reduction processes. In annual anomaly analyses covering a 9-year period, the NEP was found to be negative in 2003 and 2006 (-0.11 and -0.25 TgC/year) and positive in 2004 and 2007 (+0.02 and +0.21 TgC/year). We found that the negative values were caused by decreases in solar radiation and air temperature and the positive values were caused by increases in these two parameters and precipitation. In response to the NEP, our obtained harvested grain biomass values in 2003 and 2006 were lower than usual. The results were in good agreement with the results from reports of the Japan Meteorological Agency and the Ministry of Agriculture, Forestry, and Fisheries.

  20. Rapid Identification of Major QTLs Associated with Rice Grain Weight and Their Utilization.

    PubMed

    Xu, Feifei; Sun, Xiao; Chen, Yaling; Huang, Yan; Tong, Chuan; Bao, Jinsong

    2015-01-01

    To uncover the genetics of rice grain weight, we constructed an RIL population derived from a cross between a large grain accession M201 and a small size variety JY293. Specific Locus Amplified Fragment Sequencing (SLAF-Seq) technology was used to genotype two bulked DNA pools made from individual DNA of the heaviest 30 lines and the lightest 30 lines according to the 1000 grain weight (TGW). Bulked segregant analysis (BSA) was used to identify SLAFs strongly associated with TGW. Two marker-intensive regions at 24,600,000-24,850,000 bp and 25,000,000-25,350,000 bp on chromosome 3 were identified tightly related to the TGW. Then a linkage map of chromosome 3 was constructed with SSR markers and some SLAF derived single nucleotide polymorphisms (SNPs). Quantitative trait locus (QTL) mapping for TGW, grain length, grain width, and grain thickness revealed one major QTL in the second hot-region and two other minor QTLs for grain weight. These three QTLs displayed hierarchical effects on grain length and grain weight in order of qTGW3.2 (qGL3) qTGW3.1 (GS3) qTGW3.3. Multiple comparisons of means among the eight combinations of 3 QTLs revealed that the lines with two of three QTLs deriving from M201 displayed a large grain weight phenotype (TGW 40.2g, average data of three years) and lines with both qTGW3.1 and qTGW3.3 alleles from M201 (42.5g) had similar grain weight to the qTGW3.2 (40.8g) alone. Two strategies with similar effectiveness were proposed to improve grain weight by marker-assisted selection (MAS). One is to introduce the novel qTGW3.2 allele alone, and the other is to pyramid qTGW3.1 and qTGW3.3 alleles together. One new allele of GS3 (39 bp deletion in intron 1) and two SNPs in coding sequence of qGL3 identified in this study from M201 are useful in pyramiding elite alleles for molecular breeding for improvement of rice yield. PMID:25815721

  1. Rapid Identification of Major QTLs Associated with Rice Grain Weight and Their Utilization

    PubMed Central

    Xu, Feifei; Sun, Xiao; Chen, Yaling; Huang, Yan; Tong, Chuan; Bao, Jinsong

    2015-01-01

    To uncover the genetics of rice grain weight, we constructed an RIL population derived from a cross between a large grain accession M201 and a small size variety JY293. Specific Locus Amplified Fragment Sequencing (SLAF-Seq) technology was used to genotype two bulked DNA pools made from individual DNA of the heaviest 30 lines and the lightest 30 lines according to the 1000 grain weight (TGW). Bulked segregant analysis (BSA) was used to identify SLAFs strongly associated with TGW. Two marker-intensive regions at 24,600,000–24,850,000 bp and 25,000,000–25,350,000 bp on chromosome 3 were identified tightly related to the TGW. Then a linkage map of chromosome 3 was constructed with SSR markers and some SLAF derived single nucleotide polymorphisms (SNPs). Quantitative trait locus (QTL) mapping for TGW, grain length, grain width, and grain thickness revealed one major QTL in the second hot-region and two other minor QTLs for grain weight. These three QTLs displayed hierarchical effects on grain length and grain weight in order of qTGW3.2 (qGL3) qTGW3.1 (GS3) qTGW3.3. Multiple comparisons of means among the eight combinations of 3 QTLs revealed that the lines with two of three QTLs deriving from M201 displayed a large grain weight phenotype (TGW 40.2g, average data of three years) and lines with both qTGW3.1 and qTGW3.3 alleles from M201 (42.5g) had similar grain weight to the qTGW3.2 (40.8g) alone. Two strategies with similar effectiveness were proposed to improve grain weight by marker-assisted selection (MAS). One is to introduce the novel qTGW3.2 allele alone, and the other is to pyramid qTGW3.1 and qTGW3.3 alleles together. One new allele of GS3 (39 bp deletion in intron 1) and two SNPs in coding sequence of qGL3 identified in this study from M201 are useful in pyramiding elite alleles for molecular breeding for improvement of rice yield. PMID:25815721

  2. Comparison and heritability of major rice end-use quality traits among diverse accessions grown in both tropical and temperate USA environments and genetic marker implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growing environment has been well-documented as playing a large role in effecting the end-use quality traits of rice. Apparent amylose content (AAC) and gelatinization temperature (GT) are considered to be the two most important end-use quality characteristics in rice, defining the major classes tha...

  3. Health Benefits and Clinical Impact of Major Nutrient, Red Yeast Rice: A Review

    Microsoft Academic Search

    M. Kalaivani; R. Sabitha; V. Kalaiselvan; A. Rajasekaran

    2010-01-01

    Chinese red yeast rice (RYR), a natural food obtained after fermenting rice with Monascus purpureus. RYR contains unsaturated fatty acids, sterols, B-complex vitamins and monacolins with antioxidant properties. Scientific\\u000a evidences showed that fermented RYR proved to be effective for the management of cholesterol, diabetes, cardiovascular disease\\u000a (CVD) and also for the prevention of cancer. This review article describe about the

  4. Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical forests.

    PubMed

    Metcalfe, Daniel B; Asner, Gregory P; Martin, Roberta E; Silva Espejo, Javier E; Huasco, Walter Huaraca; Farfán Amézquita, Felix F; Carranza-Jimenez, Loreli; Galiano Cabrera, Darcy F; Baca, Liliana Durand; Sinca, Felipe; Huaraca Quispe, Lidia P; Taype, Ivonne Alzamora; Mora, Luzmila Eguiluz; Dávila, Angela Rozas; Solórzano, Marlene Mamani; Puma Vilca, Beisit L; Laupa Román, Judith M; Guerra Bustios, Patricia C; Revilla, Norma Salinas; Tupayachi, Raul; Girardin, Cécile A J; Doughty, Christopher E; Malhi, Yadvinder

    2014-03-01

    The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phosphorus, and secondly, that the estimated herbivore-mediated flux of foliar nitrogen and phosphorus from plants to soil via leaf area loss is similar to, or greater than, other major sources of these nutrients in tropical forests. Finally, we estimate that herbivores consume a significant portion of plant carbon, potentially causing major shifts in the pattern of plant and soil carbon cycling. We conclude that future shifts in herbivore abundance and activity as a result of environmental change could have major impacts on soil fertility and ecosystem carbon sequestration in tropical forests. PMID:24372865

  5. Development of pyramidal lines with two major QTLs conferring resistance to sheath blight in rice (Oryza sativa L.)

    NASA Astrophysics Data System (ADS)

    Hossain, Md Kamal; Jena, Kshirod; Bhuiyan, Md Atiqur Rahman; Ratnam, Wickneswari

    2014-09-01

    Sheath blight is an emerging threat in rice cultivation. It is animportant disease caused by the soil-borne necrotrophic pathogenic fungus, Rhizoctonia solani Kühn. However, to date neither known major genes for quantitative resistance, nor any rice lines immune to this disease has been identified. The disease resistance is quantitative in nature. Numerous genes are involved in this resistance process. There are few quantitative trait loci (QTLs) detected conferring improved resistance against the disease. Teqing and Tetepshowimproved resistance having QTLs, qSB-9 and qSBR11-1, respectively. Since, these QTLs demonstrates additive effects, pyramiding of these QTLs might be an option to increase the sheath blight resistance in rice. Nine rice cultivars were screened at greenhouse conditions. Results showed that Tetep and Teqing had the lowest disease ratings. UKMRC2a new high yielding cultivar was as recipient parent. Crosses between UKMRC2 and Teqing, and UKMRC2 and Tetep were made and confirmed. Subsequently 4-way crosses between the two F1s were performed to develop pyramidal lines.

  6. Assessing Major Ecosystem Types and the Challenge of Sustainability in Turkey

    NASA Astrophysics Data System (ADS)

    Evrendilek, Fatih; Doygun, Hakan

    2000-11-01

    In recent years, Turkey has experienced rapid economic and population growth coupled with both an equally rapid increase in energy consumption and a vast disparity in welfare between socioeconomic groups and regions. In turn, these pressures have accelerated the destruction of productive, assimilative, and regenerative capacities of the ecosystems, which are essential for the well-being of the people and the economy. This paper describes the structure and function of major ecosystem types in Turkey and discusses the underlying causes of environmental degradation in the framework of economy, energy, environment, and ethics. From a national perspective, this paper suggests three sustainability-based policies necessary for Turkey's long-term interests that balance economic, environmental, and energy goals: (1) decoupling economic growth from energy consumption growth through the development of energy-efficient and renewable energy technologies; (2) linking economic efficiency and distributive justice of wealth and power through distributive and participatory public policies; and (3) integrating the economic and ecological systems through the internalization of externalities and ecosystem rehabilitation.

  7. A major QTL, Ghd8, plays pleiotropic roles in regulating grain productivity, plant height, and heading date in rice.

    PubMed

    Yan, Wen-Hao; Wang, Peng; Chen, Hua-Xia; Zhou, Hong-Ju; Li, Qiu-Ping; Wang, Chong-Rong; Ding, Ze-Hong; Zhang, Yu-Shan; Yu, Si-Bin; Xing, Yong-Zhong; Zhang, Qi-Fa

    2011-03-01

    Rice yield and heading date are two distinct traits controlled by quantitative trait loci (QTLs). The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height. Two sets of near isogenic line populations were developed for the cloning of Ghd8. Ghd8 was narrowed down to a 20-kb region containing two putative genes, of which one encodes the OsHAP3 subunit of a CCAAT-box binding protein (HAP complex); this gene was regarded as the Ghd8 candidate. A complementary test confirmed the identity and pleiotropic effects of the gene; interestingly, the genetic effect of Ghd8 was dependent on its genetic background. By regulating Ehd1, RFT1, and Hd3a, Ghd8 delayed flowering under long-day conditions, but promoted flowering under short-day conditions. Ghd8 up-regulated MOC1, a key gene controlling tillering and branching; this increased the number of tillers, primary and secondary branches, thus producing 50% more grains per plant. The ectopic expression of Ghd8 in Arabidopsis caused early flowering by 10?d-a situation similar to the one observed by its homolog AtHAP3b, when compared to wild-type under long-day conditions; these findings indicate the conserved function of Ghd8 and AtHAP3b in flowering in Arabidopsis. Our results demonstrated the important roles of Ghd8 in rice yield formation and flowering, as well as its opposite functions in flowering between rice and Arabidopsis under long-day conditions. PMID:21148627

  8. Elevated CO2 facilitates C and N accumulation in a rice paddy ecosystem.

    PubMed

    Guo, Jia; Zhang, Mingqian; Wang, Xiaowen; Zhang, Weijian

    2015-03-01

    Elevated CO2 can stimulate wetland carbon (C) and nitrogen (N) exports through gaseous and dissolved pathways, however, the consequent influences on the C and N pools are still not fully known. Therefore, we set up a free-air CO2 enrichment experiment in a paddy field in Eastern China. After five year fumigation, we studied C and N in the plant-water-soil system. The results showed: (1) elevated CO2 stimulated rice aboveground biomass and N accumulations by 19.1% and 12.5%, respectively. (2) Elevated CO2 significantly increased paddy soil TOC and TN contents by 12.5% and 15.5%, respectively in the 0-15cm layer, and 22.7% and 26.0% in the 15-30cm soil layer. (3) Averaged across the rice growing period, elevated CO2 greatly increased TOC and TN contents in the surface water by 7.6% and 11.4%, respectively. (4) The TOC/TN ratio and natural ?(15)N value in the surface soil showed a decreasing trend under elevated CO2. The above results indicate that elevated CO2 can benefit C and N accumulation in paddy fields. Given the similarity between the paddies and natural wetlands, our results also suggest a great potential for long-term C and N accumulation in natural wetlands under future climate patterns. PMID:25766010

  9. Molecular Genetic Diversity of Major Indian Rice Cultivars over Decadal Periods

    PubMed Central

    Deborah, Dondapati Annekitty; Vipparla, Abhilash; Anuradha, Ghanta; Siddiq, Ebrahimali Abubacker; Vemireddy, Lakshminarayana Reddy

    2013-01-01

    Genetic diversity in representative sets of high yielding varieties of rice released in India between 1970 and 2010 was studied at molecular level employing hypervariable microsatellite markers. Of 64 rice SSR primer pairs studied, 52 showed polymorphism, when screened in 100 rice genotypes. A total of 184 alleles was identified averaging 3.63 alleles per locus. Cluster analysis clearly grouped the 100 genotypes into their respective decadal periods i.e., 1970s, 1980s, 1990s and 2000s. The trend of diversity over the decadal periods estimated based on the number of alleles (Na), allelic richness (Rs), Nei’s genetic diversity index (He), observed heterozygosity (Ho) and polymorphism information content (PIC) revealed increase of diversity over the periods in year of releasewise and longevitywise classification of rice varieties. Analysis of molecular variance (AMOVA) suggested more variation in within the decadal periods than among the decades. Pairwise comparison of population differentiation (Fst) among decadal periods showed significant difference between all the pairs except a few. Analysis of trends of appearing and disappearing alleles over decadal periods showed an increase in the appearance of alleles and decrease in disappearance in both the categories of varieties. It was obvious from the present findings, that genetic diversity was progressively on the rise in the varieties released during the decadal periods, between 1970s and 2000s. PMID:23805204

  10. FINE MAPPING OF THE QCTS12 LOCUS, A MAJOR QTL FOR SEEDLING COLD TOLERANCE IN RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The temperate japonica rice cultivar M-202 is the predominant variety grown in California due to its tolerance to low temperature stress, good grain quality and high yield. Earlier analysis of a recombinant inbred line mapping population derived from a cross between M-202 and IR50, an indica cultiva...

  11. Mutation of a major CG methylase in rice causes genome-wide hypomethylation, dysregulated genome expression, and seedling lethality.

    PubMed

    Hu, Lanjuan; Li, Ning; Xu, Chunming; Zhong, Silin; Lin, Xiuyun; Yang, Jingjing; Zhou, Tianqi; Yuliang, Anzhi; Wu, Ying; Chen, Yun-Ru; Cao, Xiaofeng; Zemach, Assaf; Rustgi, Sachin; von Wettstein, Diter; Liu, Bao

    2014-07-22

    Cytosine methylation at CG sites ((m)CG) plays critical roles in development, epigenetic inheritance, and genome stability in mammals and plants. In the dicot model plant Arabidopsis thaliana, methyltransferase 1 (MET1), a principal CG methylase, functions to maintain (m)CG during DNA replication, with its null mutation resulting in global hypomethylation and pleiotropic developmental defects. Null mutation of a critical CG methylase has not been characterized at a whole-genome level in other higher eukaryotes, leaving the generality of the Arabidopsis findings largely speculative. Rice is a model plant of monocots, to which many of our important crops belong. Here we have characterized a null mutant of OsMet1-2, the major CG methylase in rice. We found that seeds homozygous for OsMet1-2 gene mutation (OsMET1-2(-/-)), which directly segregated from normal heterozygote plants (OsMET1-2(+/-)), were seriously maldeveloped, and all germinated seedlings underwent swift necrotic death. Compared with wild type, genome-wide loss of (m)CG occurred in the mutant methylome, which was accompanied by a plethora of quantitative molecular phenotypes including dysregulated expression of diverse protein-coding genes, activation and repression of transposable elements, and altered small RNA profiles. Our results have revealed conservation but also distinct functional differences in CG methylases between rice and Arabidopsis. PMID:25002488

  12. Simulation of future global warming scenarios in rice paddies with an open-field ecosystem warming facility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) in Yangtze River Valley (YRV) suffered serious yield losses in 2003 when extreme heatwave (HW), hampered rice reproductive growth phase (RGP). Climate change induced extreme and asymmetrical fluctuations in temperature during heat sensitive stage of rice growth cycle, i.e., RG...

  13. QTL analysis for rice grain length and fine mapping of an identified QTL with stable and major effects.

    PubMed

    Wan, X Y; Wan, J M; Jiang, L; Wang, J K; Zhai, H Q; Weng, J F; Wang, H L; Lei, C L; Wang, J L; Zhang, X; Cheng, Z J; Guo, X P

    2006-05-01

    Grain length in rice plays an important role in determining rice appearance, milling, cooking and eating quality. In this study, the genetic basis of grain length was dissected into six main-effect quantitative trait loci (QTLs) and twelve pairs of epistatic QTLs. The stability of these QTLs was evaluated in four environments using an F7 recombinant inbred line (RIL) population derived from the cross between a Japonica variety, Asominori, and an Indica variety, IR24. Moreover, chromosome segment substitution lines (CSSLs) harboring each of the six main-effect QTLs were used to evaluate gene action of QTLs across eight environments. A major QTL denoted as qGL-3a, was found to express stably not only in the isogenic background of Asominori but also in the recombinant background of Asominori and IR24 under multiple environments. The IR24 allele at qGL-3a has a positive effect on grain length. Based on the test of advanced backcross progenies, qGL-3a was dissected as a single Mendelian factor, i.e., long rice grain was controlled by a recessive gene gl-3. High-resolution genetic and physical maps were further constructed for fine mapping gl-3 by using 11 simple sequence repeat (SSR) markers designed using sequence information from seven BAC/PAC clones and a BC4F2 population consisting of 2,068 individuals. Consequently, the gl-3 gene was narrowed down to a candidate genomic region of 87.5 kb long defined by SSR markers RMw357 and RMw353 on chromosome 3, which provides a basis for map-based cloning of this gene and for marker-aided QTL pyramiding in rice quality breeding. PMID:16477428

  14. Long-term changes in soil pH across major forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Yang, Yuanhe; Li, Pin; He, Honglin; Zhao, Xia; Datta, Arindam; Ma, Wenhong; Zhang, Ying; Liu, Xuejun; Han, Wenxuan; Wilson, Maxwell C.; Fang, Jingyun

    2015-02-01

    Atmospheric acidic deposition has been a major environmental problem since the industrial revolution. However, our understanding of the effect of acidic deposition on soil pH is inconclusive. Here we examined temporal variations in topsoil pH and their relationships with atmospheric sulfur and nitrogen deposition across China's forests from the 1980s to the 2000s. To accomplish this goal, we conducted artificial neural network simulations using historical soil inventory data from the 1980s and a data set synthesized from literature published after 2000. Our results indicated that significant decreases in soil pH occurred in broadleaved forests, while minor changes were observed in coniferous and mixed coniferous and broadleaved forests. The magnitude of soil pH change was negatively correlated with atmospheric sulfur and nitrogen deposition. This relationship highlights the need for stringent measures that reduce sulfur and nitrogen emissions so as to maintain ecosystem structure and function.

  15. Ecosystems

    NSDL National Science Digital Library

    Houghton Mifflin Science

    This self-contained module on ecosystems includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

  16. Major cis-regulatory elements for rice bidirectional promoter activity reside in the 5'-untranslated regions.

    PubMed

    Dhadi, Surendar Reddy; Deshpande, Aparna; Driscoll, Kyle; Ramakrishna, Wusirika

    2013-09-10

    Bidirectional promoters are defined as those that regulate adjacent genes organized in a divergent fashion (head to head orientation) and separated by <1 kb. In order to dissect bidirectional promoter activity in a model plant, deletion analysis was performed for seven rice promoters using promoter-reporter gene constructs, which identified three promoters to be bidirectional. Regulatory elements located in or close to the 5'-untranslated regions (UTR) of one of the genes (divergent gene pair) were found to be responsible for their bidirectional activity. DNA footprinting analysis identified unique protein binding sites in these promoters. Deletion/alteration of these motifs resulted in significant loss of expression of the reporter genes on either side of the promoter. Changes in the motifs at both the positions resulted in a remarkable decrease in bidirectional activity of the reporter genes flanking the promoter. Based on our results, we propose a novel mechanism for the bidirectionality of rice bidirectional promoters. PMID:23756196

  17. Aquaporins are major determinants of water use efficiency of rice plants in the field.

    PubMed

    Nada, Reham M; Abogadallah, Gaber M

    2014-10-01

    This study aimed at specifying the reasons of unbalanced water relations of rice in the field at midday which results in slowing down photosynthesis and reducing water use efficiency (WUE) in japonica and indica rice under well-watered and droughted conditions. Leaf relative water content (RWC) decreased in the well-watered plants at midday in the field, but more dramatically in the droughted indica (75.6 and 71.4%) than japonica cultivars (85.5 and 80.8%). Gas exchange was measured at three points during the day (9:00, 13:00 and 17:00). Leaf internal CO2 (Ci) was not depleted when midday stomatal depression was highest indicating that Ci was not limiting to photosynthesis. Most aquaporins were predominantly expressed in leaves suggesting higher water permeability in leaves than in roots. The expression of leaf aquaporins was further induced by drought at 9:00 without comparable responses in roots. The data suggest that aquaporin expression in the root endodermis was limiting to water uptake. Upon removal of the radial barriers to water flow in roots, transpiration increased instantly and photosynthesis increased after 4h resulting in increasing WUE after 4h, demonstrating that WUE in rice is largely limited by the inadequate aquaporin expression profiles in roots. PMID:25219318

  18. Major Phenolic Compounds, Antioxidant Capacity and Antidiabetic Potential of Rice Bean (Vigna umbellata L.) in China

    PubMed Central

    Yao, Yang; Cheng, Xu-Zhen; Wang, Li-Xia; Wang, Su-Hua; Ren, Guixing

    2012-01-01

    Interest in edible beans as nutraceuticals is increasing. In the present study, the individual phenolic acids, the total phenolic content (TPC), the total flavonoid content (TFC), and the antioxidant and antidiabetic potential of 13 varieties of rice beans from China were investigated. Eight phenolic compounds (catechin, epicatechin, p-coumaric acid, ferulic acid, vitexin, isovitexin, sinapic acid, quercetin) were analyzed on an ultra-performance liquid chromatography (UPLC) mass spectrometry (MS) system. The rice bean varieties had significant differences in total phenolic compounds (ranging from 123.09 ± 10.35 to 843.75 ± 30.15 ?g/g), in TPC (ranging from 3.27 ± 0.04 to 6.43 ± 0.25 mg gallic acid equivalents (GAE)/g), in TFC (ranging from 55.95 ± 11.16 to 320.39 ± 31.77 mg catechin (CE)/g), in antioxidant activity (ranging from 39.87 ± 1.37 to 46.40 ± 2.18 ?M·TE/g), in ?-glucosidase inhibition activity (ranging from 44.32 ± 2.12 to 68.71 ± 2.19) and in advanced glycation end products formation inhibition activity (ranging from 34.11 ± 0.59 to 75.75 ± 0.33). This study is the first report on phytochemistry and biological activities in rice beans. PMID:22489119

  19. A process-based model of N2O emission from a rice-winter wheat rotation agro-ecosystem: Structure, validation and sensitivity

    NASA Astrophysics Data System (ADS)

    Zhou, Zaixing; Zheng, Xunhua; Xie, Baohua; Han, Shenghui; Liu, Chunyan

    2010-01-01

    In order to numerically simulate daily nitrous oxide (N2O) emission from a rice-winter wheat rotation cropping system, a process-based site model was developed (referred to as IAP-N-GAS) to track the movement and transformation of several forms of nitrogen in the agro-ecosystem, which is affected by climate, soil, crop growth and management practices. The simulation of daily N2O fluxes, along with key daily environmental variables, was validated with three-year observations conducted in East China. The validation demonstrated that the model simulated well daily solar radiation, soil temperature and moisture, and also captured the dynamics and magnitude of accumulated rice aboveground biomass and mineral nitrogen in the soil. The simulated daily N2O emissions over all three years investigated were generally in good agreement with field observations. Particularly well simulated were the peak N2O emissions induced by fertilizations, rainfall events or mid-season drainages. The model simulation also represented closely the inter-annual variation in N2O emission. These validations imply that the model has the capability to capture the general characteristics of N2O emission from a typical rice-wheat rotation agro-ecosystem. Sensitivity analyses revealed that the simulated N2O emission is most sensitive to the fertilizer application rate and the soil organic matter content, but it is much less sensitive to variations in soil pH and texture, temperature, precipitation and crop residue incorporation rate under local conditions.

  20. Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems

    PubMed Central

    Burkholder, JoAnn; Eggleston, David; Glasgow, Howard; Brownie, Cavell; Reed, Robert; Janowitz, Gerald; Posey, Martin; Melia, Greg; Kinder, Carol; Corbett, Reide; Toms, David; Alphin, Troy; Deamer, Nora; Springer, Jeffrey

    2004-01-01

    Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle–Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms. PMID:15199179

  1. Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems.

    PubMed

    Burkholder, JoAnn; Eggleston, David; Glasgow, Howard; Brownie, Cavell; Reed, Robert; Janowitz, Gerald; Posey, Martin; Melia, Greg; Kinder, Carol; Corbett, Reide; Toms, David; Alphin, Troy; Deamer, Nora; Springer, Jeffrey

    2004-06-22

    Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle-Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms. PMID:15199179

  2. Interacting Factors Driving a Major Loss of Large Trees with Cavities in a Forest Ecosystem

    PubMed Central

    Lindenmayer, David B.; Blanchard, Wade; McBurney, Lachlan; Blair, David; Banks, Sam; Likens, Gene E.; Franklin, Jerry F.; Laurance, William F.; Stein, John A. R.; Gibbons, Philip

    2012-01-01

    Large trees with cavities provide critical ecological functions in forests worldwide, including vital nesting and denning resources for many species. However, many ecosystems are experiencing increasingly rapid loss of large trees or a failure to recruit new large trees or both. We quantify this problem in a globally iconic ecosystem in southeastern Australia – forests dominated by the world's tallest angiosperms, Mountain Ash (Eucalyptus regnans). Tree, stand and landscape-level factors influencing the death and collapse of large living cavity trees and the decay and collapse of dead trees with cavities are documented using a suite of long-term datasets gathered between 1983 and 2011. The historical rate of tree mortality on unburned sites between 1997 and 2011 was >14% with a mortality spike in the driest period (2006–2009). Following a major wildfire in 2009, 79% of large living trees with cavities died and 57–100% of large dead trees were destroyed on burned sites. Repeated measurements between 1997 and 2011 revealed no recruitment of any new large trees with cavities on any of our unburned or burned sites. Transition probability matrices of large trees with cavities through increasingly decayed condition states projects a severe shortage of large trees with cavities by 2039 that will continue until at least 2067. This large cavity tree crisis in Mountain Ash forests is a product of: (1) the prolonged time required (>120 years) for initiation of cavities; and (2) repeated past wildfires and widespread logging operations. These latter factors have resulted in all landscapes being dominated by stands ?72 years and just 1.16% of forest being unburned and unlogged. We discuss how the features that make Mountain Ash forests vulnerable to a decline in large tree abundance are shared with many forest types worldwide. PMID:23071486

  3. MucoRice-cholera toxin B-subunit, a rice-based oral cholera vaccine, down-regulates the expression of ?-amylase/trypsin inhibitor-like protein family as major rice allergens.

    PubMed

    Kurokawa, Shiho; Nakamura, Rika; Mejima, Mio; Kozuka-Hata, Hiroko; Kuroda, Masaharu; Takeyama, Natsumi; Oyama, Masaaki; Satoh, Shigeru; Kiyono, Hiroshi; Masumura, Takehiro; Teshima, Reiko; Yuki, Yoshikazu

    2013-07-01

    To develop a cold chain- and needle/syringe-free rice-based cholera vaccine (MucoRice-CTB) for human use, we previously advanced the MucoRice system by introducing antisense genes specific for endogenous rice storage proteins and produced a molecularly uniform, human-applicable, high-yield MucoRice-CTB devoid of plant-associated sugar. To maintain the cold chain-free property of this vaccine for clinical application, we wanted to use a polished rice powder preparation of MucoRice-CTB without further purification but wondered whether this might cause an unexpected increase in rice allergen protein expression levels in MucoRice-CTB and prompt safety concerns. Therefore, we used two-dimensional fluorescence difference gel electrophoresis and shotgun MS/MS proteomics to compare rice allergen protein expression levels in MucoRice-CTB and wild-type (WT) rice. Both proteomics analyses showed that the only notable change in the expression levels of rice allergen protein in MucoRice-CTB, compared with those in WT rice, was a decrease in the expression levels of ?-amylase/trypsin inhibitor-like protein family such as the seed allergen protein RAG2. Real-time PCR analysis showed mRNA of RAG2 reduced in MucoRice-CTB seed. These results demonstrate that no known rice allergens appear to be up-reregulated by genetic modification of MucoRice-CTB, suggesting that MucoRice-CTB has potential as a safe oral cholera vaccine for clinical application. PMID:23763241

  4. Dominance is the major genetic basis of heterosis in rice as revealed by QTL analysis using molecular markers.

    PubMed

    Xiao, J; Li, J; Yuan, L; Tanksley, S D

    1995-06-01

    A set of 194 F7 lines derived from a subspecific rice cross showing strong F1 heterosis was backcrossed to the two parents. The materials (388 BC1F7 lines, 194 F8 lines, two parents, F1) were phenotyped for 12 quantitative traits. A total of 37 significant QTLs (LOD > or = 2.0) was detected through 141 RFLP markers in the BC1F7 populations. Twenty-seven (73%) quantitative trait loci (QTLs) were detected in only one of the BC1F7 populations. In 82% of these cases, the heterozygotes were superior to the respective homozygotes. The remaining 10 (27%) QTLs were detected in both BC1F7 populations, and the heterozygote had a phenotype falling between those of the two homozygotes and in no instances were the heterozygotes found to be superior to both homozygotes. These results suggest that dominance complementation is the major genetic basis of heterosis in rice. This conclusion was strengthened by the finding that there was no correlation between most traits and overall genome heterozygosity and that there were some recombinant inbred lines in the F8 population having phenotypic values superior to the F1 for all of the traits evaluated--a result not expected if overdominance was a major contributor to heterosis. Digenic epistasis was not evident. PMID:7498751

  5. Transgenic indica rice lines, expressing Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1), exhibit enhanced resistance to major pathogens.

    PubMed

    Sadumpati, Vijayakumar; Kalambur, Muralidharan; Vudem, Dashavantha Reddy; Kirti, Pulugurtha Bharadwaja; Khareedu, Venkateswara Rao

    2013-07-10

    Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1) has been introduced into commercial indica rice varieties by Agrobacterium-mediated genetic transformation. Transgenic rice plants were regenerated from the phosphinothricin-resistant calli obtained after co-cultivation with Agrobacterium strain LBA4404 harbouring Ti plasmid pSB111-bar-BjNPR1. Molecular analyses confirmed the stable integration and expression of BjNPR1 in various transgenic rice lines. Transgenes NPR1 and bar were stably inherited and disclosed co-segregation in subsequent generations in a Mendelian fashion. Homozygous transgenic rice lines expressing BjNPR1 protein displayed enhanced resistance to rice blast, sheath blight and bacterial leaf blight diseases. Rice transformants with higher levels of NPR1 revealed notable increases in plant height, panicle length, flag-leaf length, number of seeds/panicle and seed yield/plant as compared to the untransformed plants. The overall results amply demonstrate the profound impact of BjNPR1 in imparting resistance against major pathogens of rice. The multipotent BjNPR1, as such, seems promising as a prime candidate gene to fortify crop plants with durable resistance against various pathogens. PMID:23664883

  6. Ecosystems

    NSDL National Science Digital Library

    W. R. Klemm

    2002-01-01

    This "Ecosystems" module has four units of instruction. The units include: natural selection, population balance, exchange cycles, and environmental protection. Each module has a "Hazards" link that leads to a menu of study units on various environmental hazards (such as oil spills, farm runoff, insecticides, and so on).

  7. Evolutionary responses by native species to major anthropogenic changes to their ecosystems: Pacific salmon in the Columbia River hydropower system

    Microsoft Academic Search

    ROBIN S. WAPLES; RICHARD W. ZABEL; MARK D. SCHEUERELL; BETH L. SANDERSON

    2007-01-01

    The human footprint is now large in all the Earth's ecosystems, and construction of large dams in major river basins is among the anthropogenic changes that have had the most profound ecological consequences, particularly for migratory fishes. In the Columbia River basin of the western USA, considerable effort has been directed toward evaluating demo- graphic effects of dams, yet little

  8. Biological invasions are having a major impact on the Earth's ecosystems [1], giving urgency to a better

    E-print Network

    Chesson, Peter L.

    Biological invasions are having a major impact on the Earth's ecosystems [1], giving urgency of establishment increases markedly with the rate of arrival of an alien species at a potential invasion site [2). The response aspect of the niche is fundamental to an alien species'ability to invade, and the effect aspect

  9. Quantitative trait loci linked to plant production traits in rice (Oryza sativa) under drought stress in a target

    Microsoft Academic Search

    Alagarswamy Senthila; Ranganathan Chandra Babud

    Drought stress is the major constraint to rice (Oryza sativa) production and yield stability in rainfed ecosystems. Identifying genomic regions contributing to drought resistance will help to develop rice cultivars suitable for rainfed regions through molecular marker-assisted breeding. Quantitative trait loci (QTLs) linked to plant production traits under drought stress were mapped by evaluating 155 F7 recombinant inbred (RI) lines

  10. CEBiP is the major chitin oligomer-binding protein in rice and plays a main role in the perception of chitin oligomers.

    PubMed

    Kouzai, Yusuke; Nakajima, Keisuke; Hayafune, Masahiro; Ozawa, Kenjirou; Kaku, Hanae; Shibuya, Naoto; Minami, Eiichi; Nishizawa, Yoko

    2014-03-01

    CEBiP, a plasma membrane-localized glycoprotein of rice, directly binds with chitin elicitors (CE), and has been identified as a receptor for CE by using CEBiP-RNAi rice cells. To further clarify the function of CEBiP, we produced CEBiP-disrupted rice plants by applying an efficient Agrobacterium-mediated gene-targeting system based on homologous recombination, which has recently been developed for rice. Homologous recombination occurred at the CEBiP locus in ~0.5 % of the positive/negative selected calli. In the self-pollinated next generation, it was confirmed that the first exon of CEBiP was replaced with the hygromycin selection cassette as designed, and that the expression of CEBiP was completely deficient in homozygous cebip lines. Affinity-labeling analysis using biotinylated N-acetylchitooctaose demonstrated that CEBiP is the major CE-binding protein in rice cultured cells and leaves, which was consistent with the result that the response to CE in cebip cells was greatly diminished. Nevertheless, we observed a significant decrease in disease resistance against Magnaporthe oryzae, the causal agent of rice blast disease, only when the cebip leaf sheaths were inoculated with a weakly virulent strain, suggesting that CE perception during the infection process of M. oryzae is limited. The response to peptidoglycan and lipopolysaccharides in cebip cells was not affected, strongly suggesting that CEBiP is a CE-specific receptor. PMID:24173912

  11. In Inland China, Rice, Rather than Fish, Is the Major Pathway for Methylmercury Exposure

    PubMed Central

    Zhang, Hua; Feng, Xinbin; Larssen, Thorjørn; Qiu, Guangle; Vogt, Rolf D.

    2010-01-01

    Background Fish consumption is considered the primary pathway of methylmercury (MeHg) exposure for most people in the world. However, in the inland regions of China, most of the residents eat little fish, but they live in areas where a significant amount of mercury (Hg) is present in the environment. Objectives We assessed concentrations of total Hg and MeHg in samples of water, air, agricultural products, and other exposure media to determine the main exposure pathway of Hg in populations in inland China. Methods We selected Guizhou Province for our study because it is highly contaminated with Hg and therefore is representative of other Hg-contaminated areas in China. We selected four study locations in Guizhou Province: three that represent typical environments with severe Hg pollution [due to Hg mining and smelting (Wanshan), traditional zinc smelting (recently closed; Weining), and heavy coal-based industry (Qingzhen)], and a village in a remote nature reserve (Leigong). Results The probable daily intake (PDI) of MeHg for an adult population based on 60 kg body weight (bw) was considerably higher in Wanshan than in the other three locations. With an average PDI of 0.096 ?g/kg bw/day (range, 0.015–0.45 ?g/kg bw/day), approximately 34% of the inhabitants in Wanshan exceeded the reference dose of 0.1 ?g/kg bw/day established by the U.S. Environmental Protection Agency. The PDI of MeHg for residents in the three other locations were all well below 0.1 ?g/kg bw/day (averages from 0.017 to 0.023 ?g/kg bw/day, with a maximum of 0.095 ?g/kg bw/day). In all four areas, rice consumption accounted for 94–96% of the PDI of MeHg. Conclusion We found that rice consumption is by far the most important MeHg exposure route; however, most of the residents (except those in Hg-mining areas) have low PDIs of MeHg. PMID:20378486

  12. Nucleotide Diversity Analysis of Three Major Bacterial Blight Resistance Genes in Rice

    PubMed Central

    Bimolata, Waikhom; Kumar, Anirudh; M, Sai Kiran Reddy; Sundaram, Raman Meenakshi; Laha, Gouri Sankar; Qureshi, Insaf Ahmed; Ghazi, Irfan Ahmad

    2015-01-01

    Nucleotide sequence polymorphisms among R gene alleles influence the process of co-evolutionary interaction between host and pathogen by shaping the response of host plants towards invading pathogens. Here, we present the DNA sequence polymorphisms and diversities present among natural alleles of three rice bacterial blight resistance genes, Xa21, Xa26 and xa5. The diversity was examined across different wild relatives and cultivars of Oryza species. Functional significance of selected alleles was evaluated through semi-quantitative reverse transcription polymerase chain reaction and real time PCR. The greatest nucleotide diversity and singleton variable sites (SVS) were present in Xa26 (? = 0.01958; SVS = 182) followed by xa5 and Xa21 alleles. The highest frequency of single nucleotide polymorphisms were observed in Xa21 alleles and least in xa5. Transition bias was observed in all the genes and ‘G’ to ‘A’ transitions were more favored than other form of transitions. Neutrality tests failed to show the presence of selection at these loci, though negative Tajima’s D values indicate the presence of a rare form of polymorphisms. At the interspecies level, O. nivara exhibited more diversity than O. sativa. We have also identified two nearly identical resistant alleles of xa5 and two sequentially identical alleles of Xa21. The alleles of xa5 showed basal levels of expression while Xa21 alleles were functionally not expressed. PMID:25807168

  13. Gene Expression Analysis of Rice Seedling under Potassium Deprivation Reveals Major Changes in Metabolism and Signaling Components

    PubMed Central

    Shankar, Alka; Singh, Amarjeet; Kanwar, Poonam; Srivastava, Ashish Kumar; Pandey, Amita; Suprasanna, Penna; Kapoor, Sanjay; Pandey, Girdhar K.

    2013-01-01

    Plant nutrition is one of the important areas for improving the yield and quality in crops as well as non-crop plants. Potassium is an essential plant nutrient and is required in abundance for their proper growth and development. Potassium deficiency directly affects the plant growth and hence crop yield and production. Recently, potassium-dependent transcriptomic analysis has been performed in the model plant Arabidopsis, however in cereals and crop plants; such a transcriptome analysis has not been undertaken till date. In rice, the molecular mechanism for the regulation of potassium starvation responses has not been investigated in detail. Here, we present a combined physiological and whole genome transcriptomic study of rice seedlings exposed to a brief period of potassium deficiency then replenished with potassium. Our results reveal that the expressions of a diverse set of genes annotated with many distinct functions were altered under potassium deprivation. Our findings highlight altered expression patterns of potassium-responsive genes majorly involved in metabolic processes, stress responses, signaling pathways, transcriptional regulation, and transport of multiple molecules including K+. Interestingly, several genes responsive to low-potassium conditions show a reversal in expression upon resupply of potassium. The results of this study indicate that potassium deprivation leads to activation of multiple genes and gene networks, which may be acting in concert to sense the external potassium and mediate uptake, distribution and ultimately adaptation to low potassium conditions. The interplay of both upregulated and downregulated genes globally in response to potassium deprivation determines how plants cope with the stress of nutrient deficiency at different physiological as well as developmental stages of plants. PMID:23922980

  14. Dissection of a major QTL for photoperiod sensitivity in rice: its association with a gene expressed in an age-dependent manner

    Microsoft Academic Search

    L. V. Dung; T. Inukai; Y. Sano

    1998-01-01

    A proposed major quantitative trait locus (QTL) for photoperiod sensitivity on chromosome 6 in rice was examined by introducing\\u000a a chromosomal segment from a sensitive line into an insensitive one. The crossing experiments showed that a range of variation\\u000a in heading date occurred in the later generations and that the region might contain at least a major gene and two

  15. Identification of flanking SSR markers for a major rice gall midge resistance gene Gm1 and their validation

    Microsoft Academic Search

    S. K. Biradar; R. M. Sundaram; T. Thirumurugan; J. S. Bentur; S. Amudhan; V. V. Shenoy; B. Mishra; J. Bennett; N. P. Sarma

    2004-01-01

    Host-plant resistance is the preferred strategy for management of Asian rice gall midge ( Orseolia oryzae), a serious pest in many rice-growing countries. The deployment of molecular markers linked to gall midge resistance genes in breeding programmes can accelerate the development of resistant cultivars. In the present study, we have tagged and mapped a dominant gall midge resistance gene, Gm1,

  16. Factors affecting the organochlorine pollutant load in biota of a rice field ecosystem (Ebro Delta, NE Spain)

    Microsoft Academic Search

    D. Pastor; C. Sanpera; J. González-Sol??s; X. Ruiz; J. Albaigés

    2004-01-01

    The concentrations of PCBs, DDTs, HCHs, HCB and OCS were determined in sediments and associated biota, both invertebrates (Physella acuta, Hirudo medicinalis, chironomid larvae, Hydrous pistaceus, Helochares lividus) and vertebrates (Rana perezi), in a temporary aquatic system, a rice field in the Ebro Delta (NE Spain). The qualitative and quantitative distribution of organochlorine compounds in sediments and aquatic biota has

  17. Rice ( Oryza) hemoglobins

    PubMed Central

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

    2014-01-01

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

  18. Fine mapping and identification of candidate rice genes associated with qSTV11(SG), a major QTL for rice stripe disease resistance.

    PubMed

    Kwon, Tackmin; Lee, Jong-Hee; Park, Soo-Kwon; Hwang, Un-Ha; Cho, Jun-Hyun; Kwak, Do-Yeon; Youn, Yeong-Nam; Yeo, Un-Sang; Song, You-Chun; Nam, Jaesung; Kang, Hang-Won; Nam, Min-Hee; Park, Dong-Soo

    2012-09-01

    Rice stripe disease, caused by rice stripe virus (RSV) is a serious constraint to rice production in subtropical regions of East Asia. We performed fine mapping of a RSV resistance QTL on chromosome 11, qSTV11 ( SG ), using near-isogenic lines (NILs, BC(6)F(4)) derived from a cross between the highly resistant variety, Shingwang, and the highly susceptible variety, Ilpum, using 11 insertion and deletion (InDel) markers. qSTV11 ( SG ) was localized to a 150-kb region between InDel 11 (17.86 Mbp) and InDel 5 (18.01 Mbp). Among the two markers in this region, InDel 7 is diagnostic of RSV resistance in 55 Korean japonica and indica rice varieties. InDel 7 could also distinguish the allele type of Nagdong, Shingwang, Mudgo, and Pe-bi-hun from Zenith harboring the Stv-b ( i ) allele. As a result, qSTV11 ( SG ) is likely to be the Stv-b ( i ) allele. There were 21 genes in the 150-kb region harboring the qSTV11 ( SG ) locus. Three of these genes, LOC_Os11g31430, LOC_Os11g31450, and LOC_Os11g31470, were exclusively expressed in the susceptible variety. These expression profiles were consistent with the quantitative nature along with incomplete dominance of RSV resistance. Sequencing of these genes showed that there were several amino acid substitutions between susceptible and resistant varieties. Putative functions of these candidate genes for qSTV11 (SG) are discussed. PMID:22751999

  19. QTL analysis for rice grain length and fine mapping of an identified QTL with stable and major effects

    Microsoft Academic Search

    X. Y. Wan; J. M. Wan; L. Jiang; J. K. Wang; H. Q. Zhai; J. F. Weng; H. L. Wang; C. L. Lei; X. Zhang; Z. J. Cheng; X. P. Guo

    2006-01-01

    Grain length in rice plays an important role in determining rice appearance, milling, cooking and eating quality. In this\\u000a study, the genetic basis of grain length was dissected into six main-effect quantitative trait loci (QTLs) and twelve pairs\\u000a of epistatic QTLs. The stability of these QTLs was evaluated in four environments using an F7 recombinant inbred line (RIL) population derived

  20. GS3 , a major QTL for grain length and weight and minor QTL for grain width and thickness in rice, encodes a putative transmembrane protein

    Microsoft Academic Search

    Chuchuan Fan; Yongzhong Xing; Hailiang Mao; Tingting Lu; Bin Han; Caiguo Xu; Xianghua Li; Qifa Zhang

    2006-01-01

    The GS3 locus located in the pericentromeric region of rice chromosome 3 has been frequently identified as a major QTL for both grain\\u000a weight (a yield trait) and grain length (a quality trait) in the literature. Near isogenic lines of GS3 were developed by successive crossing and backcrossing Minghui 63 (large grain) with Chuan 7 (small grain), using Minghui\\u000a 63

  1. Complex microcolinearity among wheat, rice, and barley revealed by fine mapping of the genomic region harboring a major QTL for resistance to Fusarium head blight in wheat

    Microsoft Academic Search

    Sixin Liu; Xiuling Zhang; Michael O. Pumphrey; Robert W. Stack; Bikram S. Gill; James A. Anderson

    2006-01-01

    A major quantitative trait locus (QTL), Qfhs.ndsu-3BS, for resistance to Fusarium head blight (FHB) in wheat has been identified and verified by several research groups. The objectives\\u000a of this study were to construct a fine genetic map of this QTL region and to examine microcolinearity in the QTL region among\\u000a wheat, rice, and barley. Two simple sequence repeat (SSR) markers

  2. Effect of rice hull ash silicon on rice seedling growth

    Microsoft Academic Search

    K. R. Sistani; N. K. Savant; K. C. Reddy

    1997-01-01

    Silicon (Si) promotes healthy development of rice plants. Research has shown that an adequate supply of Si to rice plants improves the plant resistance to abiotic and biotic stresses such as soil aluminum (Al) and manganese (Mn) toxicities and plant pest and diseases. Rice hull, a major by?product of rice milling, contains about 8% Si that can be recycled for

  3. Fine mapping of the qCTS12 locus, a major QTL for seedling cold tolerance in rice.

    PubMed

    Andaya, V C; Tai, T H

    2006-08-01

    The temperate japonica rice cultivar M202 is the predominant variety grown in California due to its tolerance to low temperature stress, good grain quality and high yield. Earlier analysis of a recombinant inbred line mapping population derived from a cross between M202 and IR50, an indica cultivar that is highly sensitive to cold stress, resulted in the identification of a number of QTL conferring tolerance to cold-induced wilting and necrosis. A major QTL, qCTS12, located on the short arm of chromosome 12, contributes over 40% of the phenotypic variance. To identify the gene(s) underlying qCTS12, we have undertaken the fine mapping of this locus. Saturating the short arm of chromosome 12 with microsatellite markers revealed that qCTS12 is closest to RM7003. Using RM5746 and RM3103, which are immediately outside of RM7003, we screened 1,954 F(5)-F(10) lines to find recombinants in the qCTS12 region. Additional microsatellite markers were identified from publicly available genomic sequence and used to fine map qCTS12 to a region of approximately 87 kb located on the BAC clone OSJNBb0071I17. This region contains ten open reading frames (ORFs) consisting of five hypothetical and expressed proteins of unknown function, a transposon protein, a putative NBS-LRR disease resistance protein, two zeta class glutathione S-transferases (OsGSTZ1 and OsGSTZ2), and a DAHP synthetase. Further fine mapping with markers developed from the ORFs delimited the QTL to a region of about 55 kb. The most likely candidates for the gene(s) underlying qCTS12 are OsGSTZ1 and OsGSTZ2. PMID:16741739

  4. Rice monoculture and integrated rice-fish farming in the Mekong Delta, Vietnam—economic and ecological considerations

    Microsoft Academic Search

    Håkan Berg

    2002-01-01

    This study is a survey of agriculture practices and pest management strategies among rice and rice-fish farmers in the Mekong Delta. Based on an economic comparison between different farmer categories, it is argued that rice-fish farming provides a sustainable alternative to rice monoculture, if the farmer takes full advantage of the natural productivity of the rice field ecosystem. The aim

  5. RICE AND RED RICE INTERFERENCE: II. RICE RESPONSE TO POPULATION DENSITIES OF THREE RED RICE (ORYZA SATIVA) ECOTYPES

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Development of sustainable groundwater extraction practices for a major superficial aquifer supporting a groundwater dependent ecosystem

    NASA Astrophysics Data System (ADS)

    Smettem, K. R.; Froend, R.; Davies, M.; Stock, B.; Martin, M.; Robertson, C.; Eamus, D.

    2010-12-01

    Throughout Australia many groundwater dependent ecosystems have been adversely affected by unsympathetic water abstraction practices. In Western Australia, the largest single supply of drinking water for the city of Perth is a superficial aquifer known as the Gnangara Groundwater Mound, located over an area of approximately 2200 km2 within and to the north of the city on the coastal plain. The groundwater resource supplies 60% of Perth’s pubic drinking water supply and 85% of total water demand for all users. Much of the mound is overlain by phreatophytic Banksia woodland that is susceptible to drought stress and death if the root system is separated from the unconfined aquifer for prolonged periods over the hot, dry Mediterranean summer. Drought stress has been exacerbated by diminished rainfall due to a changing climate regime. The aim of this research is to develop guidelines for sustainable groundwater abstraction (timing and volume) that will maintain the long term integrity of the ecosystem and recover up to 5GL/yr from existing borefields. We seek to investigate whether a change in abstraction regime, from ‘peak demand’ summer pumping to winter pumping allows groundwater levels to recover sufficiently prior to summer, thereby maintaining a healthy vegetation system. Hydrological and plant water status parameters were monitored over two winters at research sites with an initial depth to groundwater of less than 5m. During winter and spring, groundwater abstraction at a reduced capacity resulted in a 0.75m drawdown. Operation of the bores did not adversely impact the water status of phreatophytic Banksia at the study sites relative to control sites. Analysis of plant water source partitioning indicated that plants exposed to the winter drawdown were sustained by unsaturated zone soil moisture storage replenished by winter rainfall. When pumping ceased, the water table rose rapidly and plants utilised more groundwater during late spring and summer as the soil water store became depleted. A simple water balance model combined with phreatophyte vulnerability assessment was employed to identify allowable magnitude and rate of drawdown, and duration of bore operation.

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

    PubMed

    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. PMID:24405761

  8. Identification of flanking SSR markers for a major rice gall midge resistance gene Gm1 and their validation.

    PubMed

    Biradar, S K; Sundaram, R M; Thirumurugan, T; Bentur, J S; Amudhan, S; Shenoy, V V; Mishra, B; Bennett, J; Sarma, N P

    2004-11-01

    Host-plant resistance is the preferred strategy for management of Asian rice gall midge (Orseolia oryzae), a serious pest in many rice-growing countries. The deployment of molecular markers linked to gall midge resistance genes in breeding programmes can accelerate the development of resistant cultivars. In the present study, we have tagged and mapped a dominant gall midge resistance gene, Gm1, from the Oryza sativa cv. W1263 on chromosome 9, using SSR markers. A progeny-tested F2 mapping population derived from the cross W1263/TN1 was used for analysis. To map the gene locus, initially a subset of the F2 mapping population consisting of 20 homozygous resistant and susceptible lines each was screened with 63 parental polymorphic SSR markers. The SSR markers RM316, RM444 and RM219, located on chromosome 9, are linked to Gm1 at genetic distances of 8.0, 4.9 and 5.9 cM, respectively, and flank the gene locus. Further, gene/marker order was also determined. The utility of the co-segregating SSR markers was tested in a backcross population derived from the cross Swarna/W1263//Swarna, and allelic profiles of these markers were analysed in a set of donor rice genotypes possessing Gm1 and in a few gall midge-susceptible, elite rice varieties. PMID:15278284

  9. Fine mapping of the qCTS12 locus, a major QTL for seedling cold tolerance in rice

    Microsoft Academic Search

    V. C. Andaya; T. H. Tai

    2006-01-01

    The temperate japonica rice cultivar M202 is the predominant variety grown in California due to its tolerance to low temperature stress, good grain quality and high yield. Earlier analysis of a recombinant inbred line mapping population derived from a cross between M202 and IR50, an indica cultivar that is highly sensitive to cold stress, resulted in the identification of a

  10. Factors affecting the organochlorine pollutant load in biota of a rice field ecosystem (Ebro Delta, NE Spain).

    PubMed

    Pastor, D; Sanpera, C; González-Solís, J; Ruiz, X; Albaigés, J

    2004-04-01

    The concentrations of PCBs, DDTs, HCHs, HCB and OCS were determined in sediments and associated biota, both invertebrates (Physella acuta, Hirudo medicinalis, chironomid larvae, Hydrous pistaceus, Helochares lividus) and vertebrates (Rana perezi), in a temporary aquatic system, a rice field in the Ebro Delta (NE Spain). The qualitative and quantitative distribution of organochlorine compounds in sediments and aquatic biota has been explained by two mechanisms: equilibrium partitioning and/or biomagnification through the trophic web. Nevertheless, bioaccumulation processes are by far more complex, since several biotic and abiotic factors contribute to the observed pollutant loads in the organisms. In this respect, the biological characteristics of the organisms considered (e.g. species, age, lipid contents, feeding habits, etc.), as well as ecological factors (e.g. the habitat of the species and vertical distribution), have been shown to account for the organochlorine levels observed. PMID:15006509

  11. Rapid and high-precision marker assisted backcrossing to introgress the SUB1 QTL into BR11, the rainfed lowland rice mega variety of Bangladesh

    Microsoft Academic Search

    K. M. Iftekharuddaula; M. A. Newaz; M. A. Salam; H. U. Ahmed; M. A. A. Mahbub; E. M. Septiningsih; B. C. Y. Collard; D. L. Sanchez; A. M. Pamplona; D. J. Mackill

    2011-01-01

    Flooding is one of the major hazards of rice production for the rainfed lowland rice ecosystem, and tolerant cultivars are\\u000a urgently needed to help protect farmers from submergence damage. A quick and efficient strategy was implemented to introgress\\u000a SUB1, a major QTL for submergence tolerance, into a rainfed lowland mega variety BR11 of Bangladesh by only two backcrosses and\\u000a one

  12. Dominance Is the Major Genetic Basis of Heterosis in Rice as Revealed by QTL Analysis Using Molecular Markers

    Microsoft Academic Search

    Jinhua Xiao; Jiming Longping Yuant; Steven D. Tanksley

    1995-01-01

    A set of 194 F7 lines derived from a subspecific rice cross showing strong F1 heterosis was backcrossed to the two parents. The materials (388 BCIF7 lines, 194 F8 lines, two parents, F,) were phenotyped for 12 quantitative traits. A total of 37 significant QTLs (LOD z 2.0) was detected through 141 RFLP markers in the BCIF7 populations. Twenty-seven (73%)

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

    PubMed

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

    2009-04-01

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

  14. Carbon storage increases by major forest ecosystems in tropical South America since the Last Glacial Maximum and the early Holocene

    NASA Astrophysics Data System (ADS)

    Behling, Hermann

    2002-06-01

    To study the carbon storage increase of major forest ecosystems in tropical South America, such as Amazon rain forest, Atlantic rain forest, semideciduous forest, and Araucaria forest, the Last Glacial Maximum (LGM) and the early Holocene vegetation cover were reconstructed by pollen records. Marked forest expansion points to a significant total carbon storage increase by tropical forests in South America since the LGM and the early Holocene. The Amazon rain forest expansion, about 39% in area, had 28.3×10 9 tC (+20%), the highest carbon storage increase since the LGM. The expansion of the other much smaller forest areas also had a significant carbon storage increase since the LGM, the Atlantic rain forest with 4.9×10 9 tC (+55%), the semideciduous forest of eastern Brazil with 6.3×10 9 tC (+46%), the Araucaria forest with 3.4×10 9 tC (+108%). The estimated carbon storage increase of the four forest biomes since the early Holocene is also remarkable. The extensive deforestation in the last century strongly affected the carbon storage by tropical forests.

  15. Identification of qRL7, a major quantitative trait locus associated with rice root length in hydroponic conditions

    PubMed Central

    Wang, Huimin; Xu, Xiaoming; Zhan, Xiaodeng; Zhai, Rongrong; Wu, Weiming; Shen, Xihong; Dai, Gaoxing; Cao, Liyong; Cheng, Shihua

    2013-01-01

    Root system development is an important target for improving yield in rice. Active roots that can take up nutrients more efficiently are essential for improving grain yield. In this study, we performed quantitative trait locus (QTL) analyses using 215 recombinant inbred lines derived from a cross between Xieqingzao B (XB), a maintainer line with short roots and R9308, a restorer line with long roots. Only a QTLs associated with root length were mapped on chromosomes 7. The QTL, named qRL7, was located between markers RM3859 and RM214 on chromosome 7 and explained 18.14–18.36% of the total phenotypic variance evaluated across two years. Fine mapping of qRL7 using eight BC3F3 recombinant lines mapped the QTL to between markers InDel11 and InDel17, which delimit a 657.35 kb interval in the reference cultivar Nipponbare. To determine the genotype classes for the target QTL in these BC3F3 recombinants, the root lengths of their BC3F4 progeny were investigated, and the result showed that qRL7 plays a crucial role in root length. The results of this study will increase our understanding of the genetic factors controlling root architecture, which will help rice breeders to breed varieties with deep, strong and vigorous root systems. PMID:24273421

  16. Identification of qRL7, a major quantitative trait locus associated with rice root length in hydroponic conditions.

    PubMed

    Wang, Huimin; Xu, Xiaoming; Zhan, Xiaodeng; Zhai, Rongrong; Wu, Weiming; Shen, Xihong; Dai, Gaoxing; Cao, Liyong; Cheng, Shihua

    2013-09-01

    Root system development is an important target for improving yield in rice. Active roots that can take up nutrients more efficiently are essential for improving grain yield. In this study, we performed quantitative trait locus (QTL) analyses using 215 recombinant inbred lines derived from a cross between Xieqingzao B (XB), a maintainer line with short roots and R9308, a restorer line with long roots. Only a QTLs associated with root length were mapped on chromosomes 7. The QTL, named qRL7, was located between markers RM3859 and RM214 on chromosome 7 and explained 18.14-18.36% of the total phenotypic variance evaluated across two years. Fine mapping of qRL7 using eight BC3F3 recombinant lines mapped the QTL to between markers InDel11 and InDel17, which delimit a 657.35 kb interval in the reference cultivar Nipponbare. To determine the genotype classes for the target QTL in these BC3F3 recombinants, the root lengths of their BC3F4 progeny were investigated, and the result showed that qRL7 plays a crucial role in root length. The results of this study will increase our understanding of the genetic factors controlling root architecture, which will help rice breeders to breed varieties with deep, strong and vigorous root systems. PMID:24273421

  17. Transcriptome Profiling and Physiological Studies Reveal a Major Role for Aromatic Amino Acids in Mercury Stress Tolerance in Rice Seedlings

    PubMed Central

    Trinh, Ngoc Nam; Huang, Li-Yao; Chen, Ying-Chih; Cheng, Kai-Teng; Huang, Tsai-Lien; Lin, Chung-Yi; Huang, Hao-Jen

    2014-01-01

    Mercury (Hg) is a serious environmental pollution threat to the planet. The accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. To gain more insight into the cellular response to Hg, we performed a large-scale analysis of the rice transcriptome during Hg stress. Genes induced with short-term exposure represented functional categories of cell-wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Moreover, Hg stress upregulated several genes involved in aromatic amino acids (Phe and Trp) and increased the level of free Phe and Trp content. Exogenous application of Phe and Trp to rice roots enhanced tolerance to Hg and effectively reduced Hg-induced production of reactive oxygen species. Hg induced calcium accumulation and activated mitogen-activated protein kinase. Further characterization of the Hg-responsive genes we identified may be helpful for better understanding the mechanisms of Hg in plants. PMID:24840062

  18. College Last Name First Name Email Class Major Begnel Emily erb6@rice.edu 2015 Ecology and Evolu:onary Biology, Hispanic Studies

    E-print Network

    Engineering Jones Joyce jmj3@rice.edu 2015 Anthropology, Ancient Mediterranean Civiliza:ons Perez Studies Sengupta Shayak ss53@rice.edu 2015 Civil Engineering Maduka Nikki nm13@rice.edu 2015 Ecology Studies Jones O-Week 2014: O-Week Peer Academic Advisors Baker Brown Duncan Hanszen Athle

  19. Evolutionary responses by native species to major anthropogenic changes to their ecosystems: Pacific salmon in the Columbia River hydropower system.

    PubMed

    Waples, Robin S; Zabel, Richard W; Scheuerell, Mark D; Sanderson, Beth L

    2008-01-01

    The human footprint is now large in all the Earth's ecosystems, and construction of large dams in major river basins is among the anthropogenic changes that have had the most profound ecological consequences, particularly for migratory fishes. In the Columbia River basin of the western USA, considerable effort has been directed toward evaluating demographic effects of dams, yet little attention has been paid to evolutionary responses of migratory salmon to altered selective regimes. Here we make a first attempt to address this information gap. Transformation of the free-flowing Columbia River into a series of slack-water reservoirs has relaxed selection for adults capable of migrating long distances upstream against strong flows; conditions now favour fish capable of migrating through lakes and finding and navigating fish ladders. Juveniles must now be capable of surviving passage through multiple dams or collection and transportation around the dams. River flow patterns deliver some groups of juvenile salmon to the estuary later than is optimal for ocean survival, but countervailing selective pressures might constrain an evolutionary response toward earlier migration timing. Dams have increased the cost of migration, which reduces energy available for sexual selection and favours a nonmigratory life history. Reservoirs are a benign environment for many non-native species that are competitors with or predators on salmon, and evolutionary responses are likely (but undocumented). More research is needed to tease apart the relative importance of evolutionary vs. plastic responses of salmon to these environmental changes; this research is logistically challenging for species with life histories like Pacific salmon, but results should substantially improve our understanding of key processes. If the Columbia River is ever returned to a quasinatural, free-flowing state, remaining populations might face a Darwinian debt (and temporarily reduced fitness) as they struggle to re-evolve historical adaptations. PMID:18268786

  20. The effects of acid deposition on the biogeochemical cycles of major nutrients in miniature red spruce ecosystems

    Microsoft Academic Search

    Ruth E. Sherman; Timothy J. Fahey

    1994-01-01

    As part of an experimental study of air pollution effects on tree growth and health, we combined process studies with an ecosystem\\u000a approach to evaluate the effects of acidic deposition on soil acidification, nutrient cycling and proton fluxes in miniature\\u000a red spruce ecosystems. Ninety red spruce saplings were transplanted into 1-m diameter pots containing reconstructed soil profiles\\u000a and exposed to

  1. MOLECULAR CONTROL OF THE RICE BLAST DISEASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by Magnaporthe grisea is a major constraint to rice production worldwide. The rice blast system is one of the best-characterized monocot model systems. The goal of this project is to understand molecular mechanisms of disease resistance using rice blast as a model system....

  2. Mapping QTLs Linked to Physio-Morphological and Plant Production Traits under Drought Stress in Rice (Oryza sativa L.) in the Target Environment

    Microsoft Academic Search

    S. Michael Gomez; S. Satheesh Kumar; P. Jeyaprakash; R. Suresh; K. R. Biji; Adam H. Price; R. Chandra Babu

    Drought stress is a major constraint for rice (Oryza sativa L.) production and yield stability in rainfed ecosystems. Identifying genomic regions (QTLs) contributing in drought resistance will help to develop rice cultivars suitable for water-limiting environments through marker-assisted breeding. QTLs linked to physio-morphological and plant production traits under drought stress in the field were mapped by evaluating 177 F6 recombinant

  3. RICE CRICKET CLUB Rice University

    E-print Network

    Mellor-Crummey, John

    RICE CRICKET CLUB Rice University 6100 Main St, Houston, TX-77005 www.ruf.rice.edu/~rcc Email: rcc CRICKET CLUB which includes practice sessions, games and social gatherings conducted on and off the Rice. Every member must pay their annual dues of $________ towards membership of the Rice Cricket Club

  4. DNL1, encodes cellulose synthase-like D4, is a major QTL for plant height and leaf width in rice (Oryza sativa L.).

    PubMed

    Ding, Zhengquan; Lin, Zefeng; Li, Qin; Wu, Hao; Xiang, Chunyan; Wang, Jianfei

    2015-02-01

    To better understand the genetic of rice agronomic traits, we selected two different rice germplasms in phenotypes, Xian80 and Suyunuo, to construct genetic population for QTL analysis. A total of 25 QTLs for six traits were found in a 175 F2 population. Major QTLs, qPH12,qLW12.2, qLL12 and qGW12.1, explaining 50.00%, 57.08%, 15.41% and 22.51% phenotypic variation for plant height, leaf width, leaf length and grain width, respectively, were located on the same interval of chromosome 12 flanking SSR markers RM519 and RM1103. In consideration of the great effects on plant height and leaf width, the locus was named DNL1 (Dwarf and Narrowed Leaf 1). Using a segregating population derived from F2 heterozygous individuals, a total of 1363 dwarfism and narrowed-leaf individuals was selected for screening recombinants. By high-resolution linkage analysis in 141 recombination events, DNL1 was narrowed to a 62.39kb region of InDel markers ID12M28 and HF43. The results of ORF analysis in target region and nucleotide sequence alignment indicated that DNL1 encodes cellulose synthase-like D4 protein, and a single nucleotide substitution (C2488T) in dnl1 result in decrease in plant height and leaf width. Bioinformatical analysis demonstrated that a conserved role for OsCSLD4 in the regulation of plant growth and development. Expression analysis for OsCSLDs showed OsCSLD4 highly expressed in roots, while other CSLD members had comparatively lower expression levels. However, no clear evidence about CSLD4/DNL1 expression was associated with its function. PMID:25522878

  5. Substitution mapping of Pup1 : a major QTL increasing phosphorus uptake of rice from a phosphorus-deficient soil

    Microsoft Academic Search

    M. Wissuwa; J. Wegner; N. Ae; M. Yano

    2002-01-01

    A major QTL for P uptake had previously been mapped to a 13-cM marker interval on the long arm of chromosome 12. To map that major QTL with higher precision and certainty, a secondary mapping population was developed by backcrossing a near-isogenic line containing the QTL from the donor parent to the recurrent parent of low P uptake. Two different

  6. Estimation of aboveground biomass using in situ hyperspectral measurements in five major grassland ecosystems on the Tibetan Plateau

    Microsoft Academic Search

    Miaogen Shen; Yanhong Tang; Julia Klein; Pengcheng Zhang; Song Gu; Ayako Shimono; Jin Chen

    2008-01-01

    Aims There are numerous grassland ecosystem types on the Tibetan Pla- teau. These include the alpine meadow and steppe and degraded al- pine meadow and steppe. This study aimed at developing a method to estimate aboveground biomass (AGB) for these grasslands from hyperspectral data and to explore the feasibility of applying air\\/sat- ellite-borne remote sensing techniques to AGB estimation at

  7. Links between resources, C metabolism and the major components of bacterioplankton community structure across a range of freshwater ecosystems.

    PubMed

    Comte, Jérôme; del Giorgio, Paul A

    2009-07-01

    We explored the patterns in bacterioplankton community metabolism (BCM) and four components of community structure [composition (BCC), metabolic capacities (MC), physiological structure (PS) and single-cell characteristics (SCC)], between lakes, rivers and marshes within a watershed in Québec, to assess the connections that exist between them and with the main resources (organic matter, nutrients). Habitat types were well segregated by both resources and BCM and their corresponding dissimilarity matrices were significantly correlated, suggesting that BCM tracks resource conditions in a consistent manner across ecosystem types. MC also segregated the various habitats and was correlated to BCM but less so to resources, whereas BCC at times resulted in a clear separation of habitats, but was rarely correlated to resources and never to BCM, suggesting a higher degree of ecosystem specificity at this particular level. Finally, there was no clear separation of habitats in terms of PS and SCC, and none covaried with resources or BCM. The habitat patterns based on these different components of structure were rarely correlated to each other, indicating weak deterministic connections between them. MC appears to mediate the link between resources and BCM more directly and consistently across systems; BCC appears to be more influenced by ecosystem-specific factors that weaken its overall connection to both resources and BCM, whereas PS and SCC show no discernible patterns. Our results thus suggest that the bottom-up regulation of BCM by resources is mediated by complex shifts within components of community structure that can be directional, ecosystem-specific or apparently random, which combined nevertheless result in a systematic overall response to resources in terms of C metabolism. PMID:19508562

  8. Arsenic uptake and speciation in rice plants grown under greenhouse conditions with arsenic contaminated irrigation water

    Microsoft Academic Search

    E. Smith; A. L. Juhasz; J. Weber; R. Naidu

    2008-01-01

    The accumulation of arsenic (As) by rice (Oryza sativa L.) is of great interest considering the dietary intake of rice is potentially a major As exposure pathway in countries where rice is irrigated with As contaminated groundwater. A small scale rice paddy experiment was conducted to evaluate the uptake of As by rice. Arsenic concentrations in rice tissue increased in

  9. Regression analysis of major environmental parameters support an enhanced bioremediation of conglomerate heavy metals using an integrated ecosystem

    SciTech Connect

    Ibeanusi, V.M.; Henneman, T.; Cash, D. [Spelman College, Atlanta, GA (United States)

    1995-12-31

    We have developed an integrated ecosystem that supports the on-site speciation, detoxification, and mobilization of conglomerate toxic heavy metals of As(III), CR(VI), Pb, and Se from contaminated soil and water. The observed ecosystem dynamics of laboratory simulated ponds generated a pH profile (3-8.5) and a redox condition (0.25 V) that supported the oxidation of H{sub 3}AsO{sub 3} to H{sub 2}AsO{sub 4}. The infrared analysis of spent media identified an arsonic acid. The Cr(VI), Pb{sup 2} and Se (as in selenite) were reduced to Cr(III), PbS, and Se{sub 0}. In addition, molecular studies have identified unique protein molecules (< 10 KD) that are associated in the bioremediation processes. In these studies, the presence of a resistant bacterium (MRS-1), and cyanobacteria were highly significant in the bioremediation and sequestering of the metal ions to the pond surface. These results may have implications in the treatment of mixed wastes often encountered in mining areas.

  10. EFFECTS OF CO2 ON COMPETITION BETWEEN RICE AND BARNYARDGRASS

    EPA Science Inventory

    The atmospheric CO2 concentration is increasing. ffects of elevated CO2 on rice production could occur not only through direct impacts to rice, but also indirectly via ecosystem responses. hanged competitiveness with elevated CO2 could occur between rice hich has the C3 type of p...

  11. Genetic bases of appearance quality of rice grains in Shanyou 63, an elite rice hybrid

    Microsoft Academic Search

    Y. F. Tan; Y. Z. Xing; J. X. Li; S. B. Yu; C. G. Xu; Qifa Zhang

    2000-01-01

    Appearance quality of the rice grain represents a major problem of rice production in many rice-producing areas of the world,\\u000a especially in hybrid rice production in China. In this study, we conducted a molecular marker-based genetic analysis of the\\u000a traits that are determinants of the appearance quality of rice grains, including traits specifying grain shape and endosperm\\u000a opacity. The materials

  12. Rice Distillers Dried Grain Is a Promising Ingredient as a Partial Replacement of Plant Origin Sources in the Diet for Juvenile Red Seabream (Pagrus major)

    PubMed Central

    Choi, Jin; Rahman, Md Mostafizur; Lee, Sang-Min

    2014-01-01

    This study was designed to test the effects of dietary distillers dried grain (DDG) level on the growth performance, feed utilization, body composition and antioxidant activity of juvenile red seabream (Pagrus major). Six isonitrogenous and isocaloric diets were formulated to contain 0%, 5%, 10%, 15%, 20%, and 25% DDG from rice (designated as DDG0, DDG5, DDG10, DDG15, DDG20, and DDG25), respectively. Juvenile red seabream averaging 10.1±0.05 g were randomly distributed into 400-L tanks in a flow through systems. Three replicate groups of fish were fed one of the experimental diets to visual satiation two times a day for 10 weeks. Survival, weight gain, feed efficiency, protein efficiency ratio and hepatosomatic index of fish were not affected by dietary DDG levels (p>0.05). Proximate and amino acid composition of whole body in juvenile red seabream were not affected by dietary DDG levels (p>0.05). Plasma content of total protein, glucose, cholesterol, glutamic-pyruvic transaminase, phospholipid and triglyceride were not affected by dietary DDG levels (p>0.05). 1, 1-Diphenyl-2-picryl-hydrazyl radical and alkyl radical scavenging activities in plasma and liver of fish were not affected by dietary DDG levels (p>0.05). The results of this experiment suggest that DDG has the potential to replace plant origin ingredients such as wheat flour and corn gluten meal and could be used up to 25% in diet without incurring negative effects on the growth performance of juvenile red seabream. PMID:25358367

  13. Rice Distillers Dried Grain Is a Promising Ingredient as a Partial Replacement of Plant Origin Sources in the Diet for Juvenile Red Seabream (Pagrus major).

    PubMed

    Choi, Jin; Rahman, Md Mostafizur; Lee, Sang-Min

    2014-12-01

    This study was designed to test the effects of dietary distillers dried grain (DDG) level on the growth performance, feed utilization, body composition and antioxidant activity of juvenile red seabream (Pagrus major). Six isonitrogenous and isocaloric diets were formulated to contain 0%, 5%, 10%, 15%, 20%, and 25% DDG from rice (designated as DDG0, DDG5, DDG10, DDG15, DDG20, and DDG25), respectively. Juvenile red seabream averaging 10.1±0.05 g were randomly distributed into 400-L tanks in a flow through systems. Three replicate groups of fish were fed one of the experimental diets to visual satiation two times a day for 10 weeks. Survival, weight gain, feed efficiency, protein efficiency ratio and hepatosomatic index of fish were not affected by dietary DDG levels (p>0.05). Proximate and amino acid composition of whole body in juvenile red seabream were not affected by dietary DDG levels (p>0.05). Plasma content of total protein, glucose, cholesterol, glutamic-pyruvic transaminase, phospholipid and triglyceride were not affected by dietary DDG levels (p>0.05). 1, 1-Diphenyl-2-picryl-hydrazyl radical and alkyl radical scavenging activities in plasma and liver of fish were not affected by dietary DDG levels (p>0.05). The results of this experiment suggest that DDG has the potential to replace plant origin ingredients such as wheat flour and corn gluten meal and could be used up to 25% in diet without incurring negative effects on the growth performance of juvenile red seabream. PMID:25358367

  14. Optimizing tillage schedule for maintaining activity of the arbuscular mycorrhizal fungal population in a rainfed upland rice (Oryza sativa L.) agro-ecosystem.

    PubMed

    Maiti, D; Variar, M; Singh, R K

    2011-04-01

    Rainfed uplands in India are predominantly mono-cropped with rice (Oryza sativa L.) in the wet season (June/July to September/October) and grown under aerobic soil conditions. The remaining fallow period (winter followed by summer) of about 8-9 months leads to natural crash in the population of native arbuscular mycorrhizal fungi (AMF) in the soil. Attempts have been made to minimize this population crash by reducing soil disturbance-induced deleterious effects on native AMF activity of improperly scheduled off-season tillage, an agronomic recommendation for weed and disease (soil-borne) management, practiced by the upland farmers. On-farm (farmers' field) evaluation of effects of all suitable off-season tillage schedule combinations on rice during wet seasons of 2004, 2005, and 2006 revealed that a maximum of two off-season tillage schedules with a minimum gap of 13 weeks between them minimized the population crash of native AMF with a concomitant increase in phosphorus (P) uptake and grain yield of upland rice (variety "Vandana"). PMID:20544229

  15. 13Carbon isotope discrimination in roots and shoots of major weed species of southern U.S. rice fields and its potential use for analysis of rice-weed root interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assessing below ground plant interference in rice has been difficult in the past because thorough, accurate separation of the intertwined roots of weed and crop is extremely challenging. A d13C depletion method has been developed to assess interactions between roots of barnyardgrass and weed-suppre...

  16. Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China - VI. Changes in microbial community structure and respiratory activity

    NASA Astrophysics Data System (ADS)

    Liu, D.; Liu, X.; Liu, Y.; Li, L.; Pan, G.; Crowley, D.; Tippkötter, R.

    2011-02-01

    Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms.

  17. Advances in Drought Resistance of Rice

    Microsoft Academic Search

    Muhammad Farooq; Abdul Wahid; Dong-Jin Lee; Osamu Ito; Kadambot H. M. Siddique

    2009-01-01

    Water deficit is a serious environmental stress and the major constraint to rice productivity. Losses in rice yield due to water shortage probably exceed losses from all other causes combined and the extent of the yield loss depends on both the severity and duration of the water stress. Drought affects rice at morphological, physiological, and molecular levels such as delayed

  18. Identifying novel resistance genes in rice wild relatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Genetic, Molecular and Genomic Basis of Rice Defense against Insects

    Microsoft Academic Search

    Hao Chen; Michael J. Stout; Qian Qian; Feng Chen

    2012-01-01

    Rice is the world's most important staple crop, feeding more than half of the world's population. Insects and other arthropods present an important constraint in rice production. This paper begins with an introduction to major insect pests of rice and their impact, followed by a description of some of the approaches currently used in insect management programs of rice. Then

  20. Rice alcohol dehydrogenase 1 promotes survival and has a major impact on carbohydrate metabolism in the embryo and endosperm when seeds are germinated in partially oxygenated water

    PubMed Central

    Takahashi, Hirokazu; Greenway, Hank; Matsumura, Hideo; Tsutsumi, Nobuhiro; Nakazono, Mikio

    2014-01-01

    Background and Aims Rice (Oryza sativa) has the rare ability to germinate and elongate a coleoptile under oxygen-deficient conditions, which include both hypoxia and anoxia. It has previously been shown that ALCOHOL DEHYDROGENASE 1 (ADH1) is required for cell division and cell elongation in the coleoptile of submerged rice seedlings by means of studies using a rice ADH1-deficient mutant, reduced adh activity (rad). The aim of this study was to understand how low ADH1 in rice affects carbohydrate metabolism in the embryo and endosperm, and lactate and alanine synthesis in the embryo during germination and subsequent coleoptile growth in submerged seedlings. Methods Wild-type and rad mutant rice seeds were germinated and grown under complete submergence. At 1, 3, 5 and 7 d after imbibition, the embryo and endosperm were separated and several of their metabolites were measured and compared. Key results In the rad embryo, the rate of ethanol fermentation was halved, while lactate and alanine concentrations were 2·4- and 5·7- fold higher in the mutant than in the wild type. Glucose and fructose concentrations in the embryos increased with time in the wild type, but not in the rad mutant. The rad mutant endosperm had lower amounts of the ?-amylases RAMY1A and RAMY3D, resulting in less starch degradation and lower glucose concentrations. Conclusions These results suggest that ADH1 is essential for sugar metabolism via glycolysis to ethanol fermentation in both the embryo and endosperm. In the endosperm, energy is presumably needed for synthesis of the amylases and for sucrose synthesis in the endosperm, as well as for sugar transport to the embryo. PMID:24431339

  1. Passive microwave remote sensing for estimation of rice water content in Vietnam

    Microsoft Academic Search

    Doan Minh Chung; Bui Doan Trong; Vo Thi Lan Anh

    2003-01-01

    Rice is one of the world's major staple foods that accounts for 15% of the world's total cultivated area. In Asia where 94% of the world's rice is produced, rice is the main source of food and a significant source of income. In Vietnam, rice cultivated area occupies 47% of agricultural land of the country. Rice growing conditions are essential

  2. IDENTIFYING NOVEL R-GENES IN RICE WILD RELATIVES WITH MICROSATELLITE MARKERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice wild relatives (Oryza spp.) are an important source of novel R(resistance)-genes for rice improvement. Rice sheath blight, caused by Rhizoctonia solani, and leaf blast, caused by Magnaporthe grisea, are major fungal diseases of cultivated rice (O. sativa) in the USA and of irrigated rice world...

  3. Preferential association of endophytic bradyrhizobia with different rice cultivars and its implications for rice endophyte evolution.

    PubMed

    Piromyou, Pongdet; Greetatorn, Teerana; Teamtisong, Kamonluck; Okubo, Takashi; Shinoda, Ryo; Nuntakij, Achara; Tittabutr, Panlada; Boonkerd, Nantakorn; Minamisawa, Kiwamu; Teaumroong, Neung

    2015-05-01

    Plant colonization by bradyrhizobia is found not only in leguminous plants but also in nonleguminous species such as rice. To understand the evolution of the endophytic symbiosis of bradyrhizobia, the effect of the ecosystems of rice plantations on their associations was investigated. Samples were collected from various rice (Oryza sativa) tissues and crop rotational systems. The rice endophytic bradyrhizobia were isolated on the basis of oligotrophic properties, selective medium, and nodulation on siratro (Macroptilium atropurpureum). Six bradyrhizobial strains were obtained exclusively from rice grown in a crop rotational system. The isolates were separated into photosynthetic bradyrhizobia (PB) and nonphotosynthetic bradyrhizobia (non-PB). Thai bradyrhizobial strains promoted rice growth of Thai rice cultivars better than the Japanese bradyrhizobial strains. This implies that the rice cultivars possess characteristics that govern rice-bacterium associations. To examine whether leguminous plants in a rice plantation system support the persistence of rice endophytic bradyrhizobia, isolates were tested for legume nodulation. All PB strains formed symbioses with Aeschynomene indica and Aeschynomene evenia. On the other hand, non-PB strains were able to nodulate Aeschynomene americana, Vigna radiata, and M. atropurpureum but unable to nodulate either A. indica or A. evenia. Interestingly, the nodABC genes of all of these bradyrhizobial strains seem to exhibit low levels of similarity to those of Bradyrhizobium diazoefficiens USDA110 and Bradyrhizobium sp. strain ORS285. From these results, we discuss the evolution of the plant-bradyrhizobium association, including nonlegumes, in terms of photosynthetic lifestyle and nod-independent interactions. PMID:25710371

  4. Gaseous emissions from flooded rice paddy agriculture

    NASA Astrophysics Data System (ADS)

    Redeker, K. R.; Meinardi, S.; Blake, D.; Sass, R.

    2003-07-01

    Modification of continental land for agricultural use has increased over the last century. Atmospheric impact of this land use change has only been addressed for a few ecosystems and compounds. This paper provides, to date, the most comprehensive examination of gaseous emissions from rice paddies. We report seasonal emission ranges and integrated emission totals for 55 chemical species. This paper is the first to report emissions of isoprene, ethyl chloride, bromoform, alkyl nitrates, bromodichloromethane, hexane, and benzene from rice paddies. Emissions of alkyl nitrates, bromoform, ethyl chloride, and bromodichloromethane by terrestrial ecosystems have never before been observed. For species where emissions were observed we tentatively ascribe possible mechanisms of production; photochemical or biological production in the water column or rice plant mediated. For some compounds, during periods of maximum emissions, ambient rice paddy air concentrations may be concentrated enough to affect regional atmospheric chemistry.

  5. River discharges of water and nutrients to the Mediterranean and Black Sea: Major drivers for ecosystem changes during past and future decades?

    NASA Astrophysics Data System (ADS)

    Ludwig, Wolfgang; Dumont, Egon; Meybeck, Michel; Heussner, Serge

    2009-03-01

    Rivers are important sources of freshwater and nutrients for the Mediterranean and Black Sea. We present a reconstruction of the spatial and temporal variability of these inputs since the early 1960s, based on a review of available data on water discharge, nutrient concentrations and climatic parameters. Our compilation indicates that Mediterranean rivers suffer from a significant reduction in freshwater discharge, contrary to rivers of the Black Sea, which do not have clear discharge trends. We estimate this reduction to be at least about 20% between 1960 and 2000. It mainly reflects recent climate change, and dam construction may have reduced discharge even further. A similar decrease can also be expected for the fluxes of dissolved silica (Si), strongly controlled by water discharge and potentially reduced by river damming as well. This contrasts with the fluxes of nitrogen (N) and phosphorus (P) in Mediterranean and Black Sea rivers, which were strongly enhanced by anthropogenic sources. Their total inputs to the Mediterranean Sea could have increased by a factor of >5. While N still remained at elevated levels in 2000, P only increased up to the 1980-1990s, and then rapidly dropped down to about the initial values of the 1960s. With respect to the marine primary production that can be supported by the riverine nutrient inputs, Mediterranean and the Black Sea rivers were mostly phosphorus limited during the study period. Their anthropogenic nutrient enrichment could only have had a fertilizing effect before the general decline of the P loads. When also considering Si as a limiting element, which is the case for siliceous primary producers such as diatoms, silica limitation may have become a widespread phenomenon in the Mediterranean rivers since the early 1980s. For the Black Sea rivers, this already started the late 1960s. Gross primary production sustained by rivers (PPR) represents only less than 2% of the gross production (PP) in the Mediterranean, and less than 5% in the Black Sea. Possible ecological impacts of the changing river inputs should therefore be visible only in productive coastal areas, such as the Gulf of Lions, where PPR can reach more than two thirds of PP. Reported ecosystem changes both in the Adriatic Sea and the Black Sea are concomitant with major changes in the reconstructed river inputs. Further work combining modelling and data collection is needed to test whether this may also have been the case for coastal ecosystems at other places in the Mediterranean and Black Sea.

  6. Do Marmorkrebs, Procambarus fallax f. virginalis, threaten freshwater Japanese ecosystems?

    PubMed Central

    2012-01-01

    Background One marbled crayfish, Marmorkrebs, Procambarus fallax f. virginalis (Hagen, 1870), was discovered in a natural ecosystem in Japan in 2006. Because Marmorkrebs are parthenogenetic, they could establish a population from only a single individual, and thus pose a risk for becoming established in Japan, as they have in other countries. There are two major reasons to be concerned about the possibility of Marmorkrebs establishing viable populations in Japan. First, Japan’s only endemic crayfish, Cambaroides japonicus (De Haan, 1841), lives throughout Hokkaido and is endangered. Introduced Marmorkrebs are potential competitors that could further threaten C. japonicus. Second, Marmorkrebs live in rice paddies in Madagascar and consume rice. Marmorkrebs populations could reduce rice yields in Japan. Results We created five models in MaxEnt of the potential distribution of Marmorkrebs in Japan. All models showed eastern Honshu, Shikoku and Kyushu contain suitable habitats for Marmorkrebs. Hokkaido, the main habitat for C. japonicus, contained much less suitable habitat in most models, but is where the only Marmorkrebs in Japan to date was found. Conclusions Marmorkrebs appear to be capable of establishing populations in Japan if introduced. They appear to pose minimal threat to C. japonicus, but may negatively affect rice production. PMID:22738196

  7. Research Associate: Rice Breeding Rice Experiment Station

    E-print Network

    Schladow, S. Geoffrey

    qualifications and experience. Requirements: Job qualifications include a degree in plant breeding, agronomyResearch Associate: Rice Breeding Rice Experiment Station California Cooperative Rice Research a position to work with the RES Rice Breeding Program in screening and evaluating tolerance of rice germplasm

  8. MODELING GREENHOUSE GAS EMISSIONS FROM RICE-BASED PRODUCTION SYSTEMS: SENSITIVITY AND UPSCALING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A biogeochemical model, Denitrification-Decomposition (DNDC), was modified to enhance its capacity of predicting greenhouse gas emissions from paddy rice ecosystems. The modifications focused on soil redox potential dynamics, paddy rice management, and rice development and growth. The new model was ...

  9. Depletion of plant?available silicon in soils: A possible cause of declining rice yields

    Microsoft Academic Search

    Narayan K. Savant; Lawrence E. Datnoff; George H. Snyder

    1997-01-01

    The phenomenon of yield decline in different rice ecosystems from many parts of the world has been reported to be associated with decreases in the effective nitrogen (N) supply from soil. However, many reports in the literature suggest that silicon (Si) is an agronomically essential element for sustainable rice production. Depletion of plant?available Si in soils where rice is grown

  10. Environmental controls over methyl halide emissions from rice paddies

    Microsoft Academic Search

    K. R. Redeker; R. J. Cicerone

    2004-01-01

    This paper examines primary controlling factors that affect methyl halide emissions from rice paddy ecosystems. Observations of four cultivars under multiple growth conditions during studies in commercial fields and the University of California, Irvine, greenhouse lead to the conclusion that daily emissions of methyl halides are primarily determined by the growth stage of the rice plant, with the exception that

  11. A method for the molecular characterization of rice starch using an aqueous HPSEC-MALLS-RI system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice starch composes approximately 90% of milled rice. It is made up of two major glucose polymers, amylose and amylopectin. The amylose content of rice starch ranges from 0 to 30% w/w. Cooked rice texture and rice starch functional properties are reported to be primarily impacted by amylose content...

  12. Rice University | Rice Facts Index Undergraduates Graduates Faculty & Researchers Staff Alumni

    E-print Network

    Richards-Kortum, Rebecca

    Rice University | Rice Facts Index Undergraduates Graduates Faculty & Researchers Staff Alumni Rice Facts Rice Facts Index Rice Culture Academics Campus Features Rice Administration Resources Historical Facts Archives About OIR Rice News Feed Font Size Rice Facts Rice Culture Mission History

  13. Thermomechanical property of rice kernels studied by DMA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The thermomechanical property of the rice kernels was investigated using a dynamic mechanical analyzer (DMA). The length change of rice kernel with a loaded constant force along the major axis direction was detected during temperature scanning. The thermomechanical transition occurred in rice kernel...

  14. RICE UNIVERSITY Quantum Transport and Microwave Response in

    E-print Network

    Natelson, Douglas

    RICE UNIVERSITY Quantum Transport and Microwave Response in Modulated High-Mobility Two appreciated for their assistances on experimental processes. Majority of the work was carried out in Rice Shared Equipment and Rice Quantum Transport Lab, supported and funded by National Science foundation

  15. MAPPING R-GENES IN RICE WILD RELATIVES (ORYZA SPP.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice sheath blight caused by Rhizoctonia solani Kühn and leaf blast caused by Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa are major fungal diseases of cultivated rice (Oryza sativa L.). Rice wild relatives (Oryza spp.) are the source of several resistance (R-) genes including those for bla...

  16. Test of Some Hybrid Combinations to Rice Blast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by Magnaporthe oryzae is one of the most devastating rice diseases worldwide. Blast resistant cultivars are recognized as the most efficacious and economical way to control this disease. Genetic resistance to rice blast is generally governed by a few major genes, often in c...

  17. Approaches to eliminating arsenic hazards in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arsenic (As), which is toxic to plants and animals, is especially problematic to rice since the predominant As species are more soluble and more bioavailable under the reduced conditions of flooded rice culture. Two major problems have received international attention in efforts to minimize potentia...

  18. Ecosystem Explorations

    NSDL National Science Digital Library

    Kristen L. Gunckel

    1999-09-01

    The Ecosystem Explorations curriculum includes eleven classroom lessons. The lessons are divided into two sections--Understanding Ecosystems and Human Connections to Ecosystems. The curriculum incorporates scientific inquiry skills, cooperative l

  19. Confirming QTLs and finding additional Loci responsible for resistance to Sheath Blight in Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Rice Varieties.

    E-print Network

    Hodges, R. J.; Bollich, C. N.; Marchetti, M. A.; Webb, B. D.

    1979-01-01

    in Louisiana where blast is a problem. Brazos. This variety was developed from the cross C.I. 9545 x Nova and released by the Agricultural Research and Extension Center at Beaumont in 1974. The spikelet of Brazos is straw-colored, smooth and awnless... and is similar to Vista in this respect. Brazos' milling, cooking, eating and processing qualities are typical of traditional U.S. medium-grain rice. Its milling quality in terms of whole-grain and total milled rice is similar to Nova 76 and generally below...

  1. Avian foods, foraging and habitat conservation in world rice fields

    USGS Publications Warehouse

    Stafford, J.D.; Kaminski, R.M.; Reinecke, K.J.

    2010-01-01

    Worldwide, rice (Oryza sativa) agriculture typically involves seasonal flooding and soil tillage, which provides a variety of microhabitats and potential food for birds. Water management in rice fields creates conditions ranging from saturated mud flats to shallow (<30 cm) water, thereby attracting different guilds of birds. Grain not collected during harvest (i.e. waste rice) is typically the most abundant potential food of birds in rice fields, with estimates of seed mass from North America ranging from 66672 kg/ha. Although initially abundant after harvest, waste rice availability can be temporally limited. Few abundance estimates for other foods, such as vertebrate prey or forage vegetation, exist for rice fields. Outside North America, Europe and Japan, little is known about abundance and importance of any avian food in rice fields. Currently, flooding rice fields after harvest is the best known management practice to attract and benefit birds. Studies from North America indicate specific agricultural practices (e.g. burning stubble) may increase use and improve access to food resources. Evaluating and implementing management practices that are ecologically sustainable, increase food for birds and are agronomically beneficial should be global priorities to integrate rice production and avian conservation. Finally, land area devoted to rice agriculture appears to be stable in the USA, declining in China, and largely unquantified in many regions. Monitoring trends in riceland area may provide information to guide avian conservation planning in rice-agriculture ecosystems.

  2. Australian Wild Rice Reveals Pre-Domestication Origin of Polymorphism Deserts in Rice Genome

    PubMed Central

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

    2014-01-01

    Background Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. Results We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts). Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58Mbp region on chromosome 5, which suggests that some of the ‘polymorphism deserts’ in this and other parts of the rice genome may have originated prior to domestication due to natural selection. Conclusions Analysis of genes in the ‘polymorphism deserts’ indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security. PMID:24905808

  3. Characterization of paralogous protein families in rice

    E-print Network

    Lin, Haining

    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 ...

  4. The genetics of domestication of rice bean, Vigna umbellata

    PubMed Central

    Isemura, Takehisa; Kaga, Akito; Tomooka, Norihiko; Shimizu, Takehiko; Vaughan, Duncan Alexander

    2010-01-01

    Background and Aims The Asian genus Vigna, to which four cultivated species (rice bean, azuki bean, mung bean and black gram) belong, is suitable for comparative genomics. The aims were to construct a genetic linkage map of rice bean, to identify the genomic regions associated with domestication in rice bean, and to compare these regions with those in azuki bean. Methods A genetic linkage map was constructed by using simple sequence repeat and amplified fragment length polymorphism markers in the BC1F1 population derived from a cross between cultivated and wild rice bean. Using this map, 31 domestication-related traits were dissected into quantitative trait loci (QTLs). The genetic linkage map and QTLs of rice bean were compared with those of azuki bean. Key Results A total of 326 markers converged into 11 linkage groups (LGs), corresponding to the haploid number of rice bean chromosomes. The domestication-related traits in rice bean associated with a few major QTLs distributed as clusters on LGs 2, 4 and 7. A high level of co-linearity in marker order between the rice bean and azuki bean linkage maps was observed. Major QTLs in rice bean were found on LG4, whereas major QTLs in azuki bean were found on LG9. Conclusions This is the first report of a genetic linkage map and QTLs for domestication-related traits in rice bean. The inheritance of domestication-related traits was so simple that a few major QTLs explained the phenotypic variation between cultivated and wild rice bean. The high level of genomic synteny between rice bean and azuki bean facilitates QTL comparison between species. These results provide a genetic foundation for improvement of rice bean; interchange of major QTLs between rice bean and azuki bean might be useful for broadening the genetic variation of both species. PMID:20880934

  5. Identification of defense-related genes in rice responding to challenge by Rhizoctonia solani

    Microsoft Academic Search

    Chang-Jiang Zhao; Ai-Rong Wang; Yu-Jun Shi; Liu-Qing Wang; Wen-De Liu; Zong-Hua Wang; Guo-Dong Lu

    2008-01-01

    Rice sheath blight, caused by Rhizoctonia solani is one of the major diseases of rice. The pathogen infects rice plants directly through stomata or using lobate appressoria\\u000a and hyphal masses called infection cushions. The infection structures were normally found at 36 h post-inoculation. During\\u000a infection, the pathogenesis-related genes, PR1b and PBZ1 were induced in rice plants. To identify rice genes induced

  6. RiceCAP: Mapping rice milling yield QTL in a U.S. long grain cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole grain milling yield is a major determinant of rice crop value. Because this trait is under quantitative inheritance and is sensitive to variation due to the production environment and post-harvest handling, it is difficult to improve. This study was conducted as part of the USDA NRI RiceCAP pr...

  7. Characterization of rice blast resistance gene Pi61(t) in rice germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identification of resistance (R) genes to races of Magnaporthe oryzae in rice germplasm is essential for the development of rice cultivars with long lasting blast resistance. In the present study, one major quantitative trait locus, qPi93-3, was fine mapped using a recombinant inbred line (RIL), F8 ...

  8. Rice Diseases.

    E-print Network

    Jones, Roger K.

    1987-01-01

    constraints (particularly fuel prices) have all but eliminated this practice that served to reduce initial inoculum of many rice diseases by deep burial of sclerotia and infected crop residue. *Extension plant pathologist , The Texas A&M University System... slower to emerge may suffer reductions in stand and potential yield not encountered with varieties that emerge rapidly. Chemical seed treatment is a very cost effective way of minimizing potential damage from seedling disease. See the seed treatment...

  9. Total mercury in milled rice and brown rice from China and health risk evaluation.

    PubMed

    Zhang, Hongxia; Wang, Dongmei; Zhang, Jialing; Shang, Xiaohong; Zhao, Yunfeng; Wu, Yongning

    2014-01-01

    Total mercury (THg) levels in 440 pairs of milled rice samples and brown rice samples from 15 major rice grain-producing provinces of China were measured and the associated health risk via rice consumption for different age categories of Chinese population was also assessed. THg contents were measured by a direct mercury analyser and the limit of detection (LOD) was 1.5 ?g kg(-1). The THg levels for milled rice samples and brown rice samples varied from non-detected to 17.8 ?g kg(-1) and 1.5 to 25.4 ?g kg(-1), respectively, with a mean level of 3.4 ?g kg(-1) and 4.9 ?g kg(-1), respectively. The THg levels in all milled and brown rice samples were generally low, except three brown rice samples having concentrations above the legally set value for cereals (20 ?g kg(-1) Hg). THg intakes for different age categories were estimated according to THg content and corresponding rice consumption and the associated health risk was evaluated by the corresponding provisional tolerable weekly intake (PTWI) for THg (5.0 ?g kg(-1) bw week(-1)), which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The 50th percentile of the THg intakes via milled rice and brown rice consumption for different age categories was in the range 0.09-0.19 ?g kg(-1) bw week(-1) and 0.14-0.27 ?g kg(-1) bw week(-1), respectively, well below the PTWI, suggesting that the associated health risk is relatively low. However, the 99.9th percentile of the THg intakes for 2-4-year-old children amounted up to 20.6% of the PTWI (milled rice) and 29.5% of the PTWI (brown rice), which deserves attention. PMID:24914600

  10. Alien introgression in rice

    Microsoft Academic Search

    D. S. Brar; G. S. Khush

    1997-01-01

    Rice (Oryza sativa L.) productivity is affected by several biotic and abiotic stresses. The genetic variability for some of these stresses is limited in the cultivated rice germplasm. Moreover, changes in insect biotypes and disease races are a continuing threat to increased rice production. There is thus an urgent need to broaden the rice gene pool by introgressing genes for

  11. General Announcements Rice University

    E-print Network

    Richards-Kortum, Rebecca

    General Announcements Rice University 2006­2007 #12;NOTE without notice. William Marsh Rice University Physical Address: 6100 Main Street, Houston, Texas 77005 Address: http://www.rice.edu 2006­07 General Announcements online: http://www.rice.edu/catalog/ Please

  12. General Announcements Rice University

    E-print Network

    Richards-Kortum, Rebecca

    General Announcements Rice University 2005­2006 #12;NOTE: This catalog represents the most accurate offerings are subject to change without notice. William Marsh Rice University Physical Address:6100 Main:Campus Operator 713-348-0000 Homepage Address:http://www.rice.edu 2005­2006 General Announcements online:http://www.rice

  13. Rice Young Alumni Information

    E-print Network

    Palem, Krishna V.

    Rice Young Alumni Detailed Information: Houston Young Alumni Committee Programs 2011-2012 #12; Rice Young Alumni Information Alumni.rice.edu The Houston Young Alumni Committee Helps Shape Your Young Alumni Programs The Houston Young Alumni Committee represents the over 2,300 Rice undergrad

  14. ?-Oryzanols of North American Wild Rice (Zizania palustris).

    PubMed

    Aladedunye, Felix; Przybylski, Roman; Rudzinska, Magdalena; Klensporf-Pawlik, Dorota

    2013-08-01

    ?-Oryzanol, a natural mixture of ferulic acid esters of triterpene alcohols and sterols, are an important bioactive components present in rice bran oil. In light of the recent increase in the popularity of wild rice among consumers, and the possibility of a direct relationship between ?-oryzanol composition and its bioactivity, the oryzanol profile of major wild rice (Zizania palustris) grown in North America was studied and compared to regular brown rice (Oryza sativa L.). A total of twenty-three ?-oryzanol components were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The distribution of individual ?-oryzanols was similar for all the wild rice but significantly different from those of the regular brown rice. Unlike in the regular brown rice, a significant amount of steryl caffeate and cinnamate were found in the wild rice samples. Generally, the amounts of ?-oryzanol in the wild rice were higher compared to the regular brown rice, 1,352 vs. 688 ?g/g. The results from this study showed that wild rice had a more diverse ?-oryzanol composition and the higher amounts compared to the regular brown rice. PMID:23913975

  15. Florida Ecosystems

    NSDL National Science Digital Library

    Provided by FICUS (the Florida Internet Center for Understanding Sustainability) and the University of South Florida, this gem of a site covers Florida's native upland, freshwater, and marine ecosystems. Streamlined in organization but solid in content, Florida Ecosystems offers introductory information and photographic images of a dozen ecosystems, ranging from Pine Flatwoods and Dry Prairies to Mangrove Swamps and Coral Reefs. For students and educators interested in subtropical ecosystems, this is a nice place to start.

  16. Rice domestication: histories and mysteries.

    PubMed

    Gross, Briana L

    2012-09-01

    Domesticated rice (Oryza sativa) is one of the world's most important food crops, culturally, nutritionally and economically (Khush 1997). Thus, it is no surprise that there is intense curiosity about its genetic and geographical origins, its response to selection under domestication, and the genetic structure of its wild relative, Oryza rufipogon. Studies of Oryza attempting to answer these questions have accompanied each stage of the development of molecular markers, starting with allozymes and continuing to genome sequencing. While many of these studies have been restricted to small sample sizes, in terms of either the number of markers used or the number and distribution of the accessions, costs are now low enough that researchers are including large numbers of molecular markers and accessions. How will these studies relate to previous findings and long-held assumptions about rice domestication and evolution? If the paper in this issue of Molecular Ecology (Huang et al. 2012) is any indication, there will be some considerable surprises in store. In this study, a geographically and genomically thorough sampling of O. rufipogon and O. sativa revealed two genetically distinct groups of wild rice and also indicated that only one of these groups appears to be related to domesticated rice. While this fits well with previous studies indicating that there are genetic subdivisions within O. rufipogon, it stands in contrast to previous findings that the two major varieties of O. sativa (indica and japonica) were domesticated from two (or more) subpopulations of wild rice. PMID:22967059

  17. Genetic relationship between grain yield and the contents of protein and fat in a recombinant inbred population of rice

    Microsoft Academic Search

    Yong-Hong Yu; Gang Li; Ye-Yang Fan; Ke-Qin Zhang; Jie Min; Zhi-Wei Zhu; Jie-Yun Zhuang

    2009-01-01

    To study the genetic relationship between grain yield and the nutrient contents in rice, 209 recombinant inbred lines derived from a cross between indica rice Xieqingzao B and Milyang 46 were used to determine quantitative trait loci (QTLs) affecting the yields and contents of the two major nutritional components in brown rice. Seven traits were analyzed, including brown rice recovery

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. The complete sequence of the rice ( Oryza sativa ) chloroplast genome: Intermolecular recombination between distinct tRNA genes accounts for a major plastid DNA inversion during the evolution of the cereals

    Microsoft Academic Search

    Junzou Hiratsuka; Hiroaki Shimada; Robert Whittier; Takashi Ishibashi; Masahiro Sakamoto; Masao Mori; Chihiro Kondo; Yasuko Honji; Chong-Rong Sun; Bing-Yuan Meng; Yu-Qing Li; Akira Kanno; Yoko Nishizawa; Atsushi Hirai; Kazuo Shinozaki; Masahiro Sugiura

    1989-01-01

    Summary  The entire chloroplast genome of the monocot rice (Oryza sativa) has been sequenced and comprises 134525 bp. Predicted genes have been identified along with open reading frames (ORFs) conserved\\u000a between rice and the previously sequenced chloroplast genomes, a dicot, tobacco (Nicotiana tabacum), and a liverwort (Marchantia polymorpha). The same complement of 30 tRNA and 4 rRNA genes has been conserved

  20. Candidacy of a chitin-inducible gibberellin-responsive gene for a major locus affecting plant height in rice that is closely linked to Green Revolution gene sd1

    Microsoft Academic Search

    Mallikarjuna Rao Kovi; Yushan Zhang; Sibin Yu; Gaiyu Yang; Wenhao Yan; Yongzhong Xing

    Appropriate plant height is crucial for lodging resistance to improve the rice crop yield. The application of semi-dwarf 1 led to the green revolution in the 1960s, by predominantly increasing the rice yield. However, the frequent use of single\\u000a sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important\\u000a for the genetic

  1. Ecosystem Journalism

    ERIC Educational Resources Information Center

    Robertson, Amy; Mahlin, Kathryn

    2005-01-01

    If the organisms in a prairie ecosystem created a newspaper, what would it look like? What important news topics of the ecosystem would the organisms want to discuss? Imaginative and enthusiastic third-grade students were busy pondering these questions as they tried their hands at "ecosystem journalism." The class had recently completed a study of…

  2. Ecosystem Jenga!

    ERIC Educational Resources Information Center

    Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

    2009-01-01

    To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

  3. Rice Insect Management.

    E-print Network

    Drees, Bastiaan M.

    1983-01-01

    stink bugs migragring into rice from declining alternate host plants. "Extemioll elltom%gist . The T exas A&M UI/it 'ersity Syst em . -3- Fertilization practices also affect yield reductions crushed by rice water weevil larval populations. Rice... feeding. Resistance may result from plant characteristics which make certain varieties less attractive to pests than others. Weed control practices can reduce the number of alternate hosts in a rice field. Rice stink bug populations build up on other...

  4. Hang.Yu@rice.edu lzhong@rice.edu

    E-print Network

    Zhong, Lin

    Hang Yu Hang.Yu@rice.edu Lin Zhong lzhong@rice.edu Ashutosh Sabharwal ashu@rice.edu Department of Electrical & Computer Engineering, Rice University, Houston, TX 77005 All current mobile devices are omni

  5. In vitro digestibility and physicochemical properties of milled rice.

    PubMed

    Dhital, Sushil; Dabit, Laura; Zhang, Bin; Flanagan, Bernadine; Shrestha, Ashok K

    2015-04-01

    Rice is a staple diet as well as a major ingredient in many processed foods. The physicochemical and supra-molecular structure of eight rice varieties with amylose content from 9% to 19% were studied to elucidate the factors responsible for variation in enzymatic digestibility of raw and cooked rice. Parboiled rice had a digestion rate coefficient almost 4.5 times higher than the least digestible Low GI rice. The rate coefficient was found to be independent of helical structure and long range molecular order, possibly attributed to the effect of rice flour architecture. Strong swelling and pasting behaviour and lower gelatinisation temperature were linked with apparently higher in vitro digestibility but the relationship was statistically insignificant. It is concluded that the enzymatic susceptibility of rice flours are independent of supra-molecular structure and are most likely controlled by external factors not limited to particle size, presence of intact cell wall and other non-starch polymers. PMID:25442617

  6. Development and validation of an HPLC-DAD method for the simultaneous determination of most common rice pesticides in paddy water systems

    Microsoft Academic Search

    Emmanouil D. Tsochatzis; Roxani Tzimou-Tsitouridou; Urania Menkissoglu-Spiroudi; Dimitrios G. Karpouzas; Maria Papageorgiou

    2012-01-01

    Rice crop is mainly cultivated in large river basins which constitute unique ecosystems and their ecological quality is invaluable. However, the high loads of pesticides used in rice cultivation contribute to the contamination of the water resources in such rice-cultivated regions. To regularly monitor the quality of such water resources there is a need for a rapid and sensitive multi-residue

  7. Development and validation of an HPLC-DAD method for the simultaneous determination of most common rice pesticides in paddy water systems

    Microsoft Academic Search

    Emmanouil D. Tsochatzis; Roxani Tzimou-Tsitouridou; Urania Menkissoglu-Spiroudi; Dimitrios G. Karpouzas; Maria Papageorgiou

    2011-01-01

    Rice crop is mainly cultivated in large river basins which constitute unique ecosystems and their ecological quality is invaluable. However, the high loads of pesticides used in rice cultivation contribute to the contamination of the water resources in such rice-cultivated regions. To regularly monitor the quality of such water resources there is a need for a rapid and sensitive multi-residue

  8. Major Advisors 2014-2015 DEPARTMENT/PROGRAM ADVISOR OFFICE EMAIL

    E-print Network

    @rice.edu Weiwei Zhong (Spring 2015 only) W200P George R. Brown Hall weiwei.zhong@rice.edu Declared Majors Kate Beckingham (A-H) W130 George R. Brown Hall kate@rice.edu Dave Caprette (I-P) 327 Anderson Biological Lab Satish Nagaranjaiah 213 Ryon Lab nagaraja@rice.edu BA - ENVI Track Mason Tomson 120 Keck Hall mtomson

  9. Mapping QTLs for plant phenology and production traits using indica rice (Oryza sativa L.) lines adapted to rainfed environment.

    PubMed

    Suji, K K; Biji, K R; Poornima, R; Prince, K Silvas Jebakumar; Amudha, K; Kavitha, S; Mankar, Sumeet; Babu, R Chandra

    2012-10-01

    Drought is a major abiotic stress limiting rice production and yield stability in rainfed ecosystems. Identifying quantitative trait loci (QTL) for rice yield and yield components under water limited environments will help to develop drought resilient cultivars using marker assisted breeding (MAB) strategy. A total of 232 recombinant inbred lines of IR62266/Norungan were used to map QTLs for plant phenology and production traits under rainfed condition in target population of environments. A total of 79 QTLs for plant phenology and production traits with phenotypic variation ranging from 4.4 to 72.8% were detected under non-stress and drought stress conditions across two locations. Consistent QTLs for phenology and production traits were detected across experiments and water regimes. The QTL region, RM204-RM197-RM217 on chromosome 6 was linked to days to 50% flowering and grain yield per plant under both rainfed and irrigated conditions. The same genomic region, RM585-RM204-RM197 was also linked to harvest index under rainfed condition with positive alleles from Norungan, a local landrace. QTLs for plant production and drought resistance traits co-located near RM585-RM204-RM197-RM217 region on chromosome 6 in several rice genotypes. Thus with further fine mapping, this region may be useful as a candidate QTL for MAB, map-based cloning of genes and functional genomics studies for rainfed rice improvement. PMID:22198727

  10. Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain significant

    E-print Network

    Richards-Kortum, Rebecca

    206 Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain significant leadership roles at Rice and beyond. We provide leadership development opportunities capacity and strongest ambition for significant leadership. We seek to accomplish our mission through

  11. Wetland rice soils as sources and sinks of methane: a review and prospects for research

    Microsoft Academic Search

    S. Kumaraswamy; Arun Kumar Rath; B. Ramakrishnan; N. Sethunathan

    2000-01-01

    Rice paddies are an important human-made ecosystem for the global CH4 budget. CH4, which is produced in the predominantly anaerobic bulk soil layers, is oxidized significantly before it reaches the atmosphere.\\u000a Roots of rice, in addition to supporting the consumption of CH4, contribute to the total CH4 production in the soil. The various controls of CH4 emission from this ecosystem

  12. Freshwater Ecosystems

    NSDL National Science Digital Library

    2013-12-18

    In this activity, learners create a freshwater ecosystem in a large plastic bottle. Learners cut and prepare bottles, then fill with water, aquatic plants, snails and fish. Learners observe their mini-ecosystem over time to see what changes--such as the color of the water, the water temperature, plant growth, and behavior and/or population of the snails or fish. The activity serves as a model for larger freshwater ecosystems such as ponds, lakes, rivers, streams, wetlands, reservoirs and groundwater.

  13. Coral Ecosystems

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-06-01

    Why study coral ecosystems? Having survived millions of years, coral reefs are among the oldest and most diverse ecosystems on earth. Learning about coral ecosystems encompasses many of the 9-12 grade science curriculum standards. Life cycles of organisms, biological structure and function of organisms, and the behaviors and adaptations of organisms to their environment are all topics easily studied through a focus on coral reefs. All populations in this ecosystem are interdependent and part of a global food web. Healthy coral ecosystems are important to the humans, plants, fish, and other organisms that depend on them. However, the increasing impact of climate changes and human activities is endangering the very survival of these ecosystems. Pollution, habitat loss, invasive species, and diseases are all threats to the survival of coral ecosystems around the globe. Learning about them- "their fragility and value"- will help students understand what is needed to protect them. This SciGuide highlights outstanding NOAA resources, such as online tutorials and complete, hands-on, inquiry based lesson plans from the National Ocean Services. These resources address three areas. First, students can study the biology of the coral organism, learning about types of coral and where they are found. Next, resources focus on the populations, habitat, and dynamics of coral ecosystems. Finally, teachers and students, through online data sources and activities, learn about conservation of our coral ecosystems. Natural threats, human disturbances, and the benefits of coral protection focus students on the real world importance of science learning.

  14. Tolerance of anaerobic conditions caused by flooding during germination and early growth in rice (Oryza sativa L.)

    PubMed Central

    Miro, Berta; Ismail, Abdelbagi M.

    2013-01-01

    Rice is semi-aquatic, adapted to a wide range of hydrologies, from aerobic soils in uplands to anaerobic and flooded fields in waterlogged lowlands, to even deeply submerged soils in flood-prone areas. Considerable diversity is present in native rice landraces selected by farmers over centuries. Our understanding of the adaptive features of these landraces to native ecosystems has improved considerably over the recent past. In some cases, major genes associated with tolerance have been cloned, such as SUB1A that confers tolerance of complete submergence and SNORKEL genes that control plant elongation to escape deepwater. Modern rice varieties are sensitive to flooding during germination and early growth, a problem commonly encountered in rainfed areas, but few landraces capable of germination under these conditions have recently been identified, enabling research into tolerance mechanisms. Major QTLs were also identified, and are being targeted for molecular breeding and for cloning. Nevertheless, limited progress has been made in identifying regulatory processes for traits that are unique to tolerant genotypes, including faster germination and coleoptile elongation, formation of roots and leaves under hypoxia, ability to catabolize starch into simple sugars for subsequent use in glycolysis and fermentative pathways to generate energy. Here we discuss the state of knowledge on the role of the PDC-ALDH-ACS bypass and the ALDH enzyme as the likely candidates effective in tolerant rice genotypes. Potential involvement of factors such as cytoplasmic pH regulation, phytohormones, reactive oxygen species scavenging and other metabolites is also discussed. Further characterization of contrasting genotypes would help in elucidating the genetic and biochemical regulatory and signaling mechanisms associated with tolerance. This could facilitate breeding rice varieties suitable for direct seeding systems and guide efforts for improving waterlogging tolerance in other crops. PMID:23888162

  15. Direct and reverse pollen-mediated gene flow between GM rice and red rice weed

    PubMed Central

    Serrat, X.; Esteban, R.; Peñas, G.; Català, M. M.; Melé, E.; Messeguer, J.

    2013-01-01

    Potential risks of genetically modified (GM) crops must be identified before their commercialization, as happens with all new technologies. One of the major concerns is the proper risk assessment of adventitious presence of transgenic material in rice fields due to cross-pollination. Several studies have been conducted in order to quantify pollen-mediated gene flow from transgenic rice (Oryza sativa) to both conventional rice and red rice weed (O. sativa f. spontanea) under field conditions. Some of these studies reported GM pollen-donor rice transferring GM traits to red rice. However, gene flow also occurs in the opposite direction, in a phenomenon that we have called reverse gene flow, resulting in transgenic seeds that have incorporated the traits of wild red rice. We quantified reverse gene flow using material from two field trials. A molecular analysis based on amplified fragment length polymorphisms was carried out, being complemented with a phenotypic identification of red rice traits. In both field trials, the reverse gene flow detected was greater than the direct gene flow. The rate of direct gene flow varied according to the relative proportions of the donor (GM rice) and receptor (red rice) plants and was influenced by wind direction. The ecological impact of reverse gene flow is limited in comparison with that of direct gene flow because non-shattered and non-dormant seeds would be obtained in the first generation. Hybrid seed would remain in the spike and therefore most of it would be removed during harvesting. Nevertheless, this phenomenon must be considered in fields used for elite seed production and in developing countries where farmers often keep some seed for planting the following year. In these cases, there is a higher risk of GM red rice weed infestation increasing from year to year and therefore a proper monitoring plan needs to be established.

  16. Academic Majors Undergraduate Majors

    E-print Network

    Weston, Ken

    Community Nutrition/Health Promotion · Food Science Food Allergy · Human/Athletic Performance NutritionAcademic Majors Undergraduate Majors Food & Nutrition Sciences Dietetics Exercise Science Athletic Training Masters Majors Nutrition & Food Sciences Exercise Physiology Sports Sciences Doctoral Majors

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

    PubMed Central

    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

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

    PubMed

    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

  19. General Announcements Rice University

    E-print Network

    Richards-Kortum, Rebecca

    General Announcements Rice University 2004­2005 #12;NOTE: This catalog represents the most accurate notice. William Marsh Rice University Physical Address:6100 Main Street,Houston,Texas 77005 Mailing Address:P.O.Box 1892,Houston,Texas 77251­1892 Telephone:Campus Operator 713-348-0000 Homepage Address:http://www.rice

  20. The Recursion . . . Extended Rice . . .

    E-print Network

    Gallier, Jean

    The Recursion . . . Extended Rice . . . Creative and . . . Home Page Title Page Page 388 of 405 Go . . . Extended Rice . . . Creative and . . . Home Page Title Page Page 389 of 405 Go Back Full Screen Close Quit Rice . . . Creative and . . . Home Page Title Page Page 390 of 405 Go Back Full Screen Close Quit

  1. RICE UNIVERSITY Houston, Texas

    E-print Network

    Pentus, Mati

    RICE UNIVERSITY Houston, Texas Hierarchical Attribute Grammars: Dialects, Applications and Evaluation Algorithms by Alan Carle carle@cs.rice.edu A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy May, 1992 Rice University Department of Computer Science

  2. Rice ( Oryza sativa) allergy in rhinitis and asthma patients: A clinico-immunological study

    Microsoft Academic Search

    Raj Kumar; Prakriti Srivastava; Dolly Kumari; Hena Fakhr; S. Sridhara; Naveen Arora; S. N. Gaur; B. P. Singh

    2007-01-01

    Sensitization to foods varies in different countries reflecting a possible interaction of genetic factors, cultural and dietary habits. Rice is a major food consumed world wide and needs evaluation for IgE mediated reactions. The present study was carried out to identify rice allergy in patients of rhinitis and asthma and identify the allergenic proteins in raw and cooked rice. Of

  3. Speciation And Distribution Of Arsenic And Localization Of Nutrients In Rice Grains

    EPA Science Inventory

    Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains b...

  4. Genotype and environment effects on rice ( Oryza sativa L.) grain arsenic concentration in Bangladesh

    Microsoft Academic Search

    Zia U. Ahmed; Golam M. Panaullah; Hugh Gauch Jr; Susan R. McCouch; Wricha Tyagi; Mohammed S. Kabir; John Malcolm Duxbury

    2011-01-01

    Genetic analysis of 38 rice varieties released by the Bangladesh Rice Research Institute (BRRI) identified 34 as indica, 2 as admixed between indica and aus, and 4 as belonging to the aromatic\\/Group V subpopulation. Indica varieties developed for the two major rice-growing seasons, the wet monsoon (aman) and the dry winter (boro), were not genetically differentiated. The Additive Main Effect

  5. Advances in Mapping Loci Conferring Resistance to Rice Sheath Blight and Mining Rhizoctonia solani Resistant Resources

    Microsoft Academic Search

    Yu-xiang ZENG; Zhi-juan JI; Liang-yong MA; Xi-ming LI; Chang-deng YANG

    2011-01-01

    Sheath blight (SB) caused by Rhizoctonia solani is one of the three major diseases of rice, and now has become the most severe disease causing rice yield loss in China. Breeding and use of varieties resistant to SB is crucial in controlling the disease, but the advances achieved have been limited due to the lack of highly SB-resistant rice germplasm.

  6. Agro-economic evaluation of fertilizer recommendations for rainfed lowland rice

    Microsoft Academic Search

    S. M. Haefele; N. Sipaseuth; V. Phengsouvanna; K. Dounphady; S. Vongsouthi

    2010-01-01

    Soils used for cropping of rainfed lowland rice are frequently rather poor, and nutrient limitation is known to be a major constraint for grain yields. However, actual fertilizer use by most rainfed rice farmers is still very low even if input-responsive rice varieties are widely adopted. To address this contradiction, this study, conducted in central and southern Laos, intended to

  7. Nitrogen fixation in rice systems: state of knowledge and future prospects

    Microsoft Academic Search

    J. K. Ladha; P. M. Reddy

    2003-01-01

    Rice is the most important cereal crop. In the next three decades, the world will need to produce about 60% more rice than today's global production to feed the extra billion people. Nitrogen is the major nutrient limiting rice production. Development of fertilizer-responsive varieties in the Green Revolution, coupled with the realization by farmers of the importance of nitrogen, has

  8. Effect of furrow irrigation on the severity of false smut in susceptible rice varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    False smut is an important emerging disease of rice in the southern United States, where rice varieties that occupy the majority of production acreages are all susceptible to the disease. False smut susceptibility was evaluated in traditional paddy-rice fields, and under upland irrigated conditions...

  9. Development of drought-resistant cultivars using physiomorphological traits in rice

    Microsoft Academic Search

    S. Fukai; M. Cooper

    1995-01-01

    Drought is a major problem for rice grown under rainfed lowland and upland conditions, but progress in breeding to improve drought resistance has been slow. This paper describes patterns of water-stress development in rice fields, reviews genetic variation in physio-morphological traits for drought resistance in rice, and suggests how knowledge of stress physiology can contribute to plant breeding programmes that

  10. Engineering the Provitamin A (beta-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm

    Microsoft Academic Search

    Xudong Ye; Salim Al-Babili; Andreas Klöti; Jing Zhang; Paola Lucca; Peter Beyer; Ingo Potrykus

    2000-01-01

    Rice (Oryza sativa), a major staple food, is usually milled to remove the oil-rich aleurone layer that turns rancid upon storage, especially in tropical areas. The remaining edible part of rice grains, the endosperm, lacks several essential nutrients, such as provitamin A. Thus, predominant rice consumption promotes vitamin A deficiency, a serious public health problem in at least 26 countries,

  11. Effect of fertilizer source and rotation on grain quality in non-flooded rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water use is becoming a major issue in rice production. One way farmers are trying to conserve water is by growing rice in irrigated rows instead of permanent flooding. There is no information as to the affect that this management practice will have on rice grain quality. Also, urea which is used as...

  12. Ecosystem Resilience and Predictability

    Microsoft Academic Search

    Stephan Alexander Pietsch

    2010-01-01

    The changes in global climate expected over the course of the 21st century are among the major challenges natural ecosystems face today. Due to the unprecedented speed of temperature change and the lack of direct experience from past changes, models are the common tools used to assess the impacts of different scenarios of climate change on the performance of terrestrial

  13. Effects on aquatic ecosystems

    Microsoft Academic Search

    D.-P. Häder; H. D. Kumar; R. C. Smith; R. C. Worrest

    1998-01-01

    Regarding the effects of UV-B radiation on aquatic ecosystems, recent scientific and public interest has focused on marine primary producers and on the aquatic web, which has resulted in a multitude of studies indicating mostly detrimental effects of UV-B radiation on aquatic organisms. The interest has expanded to include ecologically significant groups and major biomass producers using mesocosm studies, emphasizing

  14. Shelf-sea ecosystems

    SciTech Connect

    Walsh, J J

    1980-01-01

    An analysis of the food chain dynamics of the Oregon, Alaskan, and New York shelves is made with respect to differences in physical forcing of these ecosystems. The world's shelves are 10% of the area of the ocean, yield 99% of the world's fish catch, and may be a major sink in the global CO/sub 2/ budget.

  15. Long-term trends in the prevalence of cancer and other major diseases among flatfish in the southeastern North Sea as indicators of changing ecosystem health.

    PubMed

    Vethaak, A Dick; Jol, Johan G; Pieters, Jan P F

    2009-03-15

    This paper analyses and discusses spatial and temporal patterns in the prevalence of major skin diseases (lymphocystis, epidermal hyperplasia/papilloma, ulcers), intestinal parasite Glugea sp., and liver cancer in dab (Limanda limanda) and flounder (Platichthys flesus) in the Dutch section of the North Sea since the mid-1980s. We have attempted to relate disease prevalence trends in both species to chemical contaminant exposure and other relevant environmental factors including fish condition factor, population density, fishing activity, and water temperature. We observed a long-term decline in chemical-related liver cancer in the populations of both species since the early 1990s. Lymphocystis and skin ulcer (flounder only) have also displayed a significant decrease since then. We conclude that the widespread decline in the prevalence of several skin diseases and liver cancer in dab and flounder in Dutch waters in the past two decades is most likely due to the improved water quality and health conditions in this region. PMID:19368228

  16. Microsatellite markers reveal multiple origins for Italian weedy rice

    PubMed Central

    Grimm, Annabelle; Fogliatto, Silvia; Nick, Peter; Ferrero, Aldo; Vidotto, Francesco

    2013-01-01

    Weedy rice (Oryza sativa L.) is one of the major issues of rice cultivation worldwide. In Italy, it infests about 70% of the total rice area. Different Weedy Rice populations can be distinguished based on variable morphological and physiological traits; however, little is known about genetic differentiation and origin of Italian weedy rice populations. The objective of this study was to genetically and morphologically characterize and compare different Italian weedy rice populations selected on the basis of different phenotypes. The main Italian rice territory was divided into 10 geographical areas in which 40 weedy rice populations were collected and grouped according to the awn traits. All the individuals of the populations were morphologically characterized according to plant and seed traits. Genetic characterization was performed using 19 SSR markers on all the collected accessions, and several rice cultivars, including some very old (late 19th century), nowadays are no longer cultivated. ANOVA showed that morphological plant and seed traits were significantly affected by the collection area and awnedness group. The importance of the awn morphology was also reflected in the Bayesian clustering where, despite a relatively low genetic diversity, the clusters displayed different awn types. An UPGMA dendrogram confirmed the clusters detected in STRUCTURE analysis and also revealed a grouping of certain old cultivars with the weedy rice, suggesting a common origin. PMID:24363904

  17. Genome duplication improves rice root resistance to salt stress

    PubMed Central

    2014-01-01

    Background Salinity is a stressful environmental factor that limits the productivity of crop plants, and roots form the major interface between plants and various abiotic stresses. Rice is a salt-sensitive crop and its polyploid shows advantages in terms of stress resistance. The objective of this study was to investigate the effects of genome duplication on rice root resistance to salt stress. Results Both diploid rice (HN2026-2x and Nipponbare-2x) and their corresponding tetraploid rice (HN2026-4x and Nipponbare-4x) were cultured in half-strength Murashige and Skoog medium with 150 mM NaCl for 3 and 5 days. Accumulations of proline, soluble sugar, malondialdehyde (MDA), Na+ content, H+ (proton) flux at root tips, and the microstructure and ultrastructure in rice roots were examined. We found that tetraploid rice showed less root growth inhibition, accumulated higher proline content and lower MDA content, and exhibited a higher frequency of normal epidermal cells than diploid rice. In addition, a protective gap appeared between the cortex and pericycle cells in tetraploid rice. Next, ultrastructural analysis showed that genome duplication improved membrane, organelle, and nuclei stability. Furthermore, Na+ in tetraploid rice roots significantly decreased while root tip H+ efflux in tetraploid rice significantly increased. Conclusions Our results suggest that genome duplication improves root resistance to salt stress, and that enhanced proton transport to the root surface may play a role in reducing Na+ entrance into the roots. PMID:25184027

  18. Rice Trade Policies and Their Implications for Food Security

    Microsoft Academic Search

    Alvaro Durand-Morat; Eric J. Wailes

    2011-01-01

    There is a strong linkage between the behavior of the rice market and the state of food security in many regions around the world, particularly in Asia, as made evident in the 2007-08 commodity crisis. Rice is a staple for the majority of the population in Asia, where roughly 60% of the close to one billion undernourished people live (FAO,

  19. Genetic markers reveal novel genes which control rice cooking quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice molecular markers have been developed in the gene (Waxy) that controls grain amylose content and the gene (Alk) that controls alkali spreading value. Both of these factors are considered the major determinants of rice cooking quality and texture. This set of markers is now being routinely used...

  20. Diurnal variations in methane emission from rice plants

    E-print Network

    Laskowski, Nicholas Aaron

    2004-11-15

    DIURNAL VARIATIONS IN METHANE EMISSION FROM RICE PLANTS A Thesis by NICHOLAS AARON LASKOWSKI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 2004 Major Subject: Soil Science DIURNAL VARIATIONS IN METHANE EMISSION FROM RICE PLANTS A Thesis by NICHOLAS AARON LASKOWSKI Submitted to the Office...

  1. EVALUATING RICE WILDE RELATIVES (ORYZA SPP.) FOR DISEASE RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice wild relatives (Oryza spp.) are an important source of novel pest resistance genes, as well as tolerance to abiotic stresses and yield enhancing traits. Rice sheath blight caused by Rhizoctonia solani Kühn and leaf blast, Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa, are major fungal d...

  2. Fine Mapping QTL for Drought Resistance Traits in Rice ( Oryza sativa L.) Using Bulk Segregant Analysis

    Microsoft Academic Search

    Arvindkumar Shivaji Salunkhe; R. Poornima; K. Silvas Jebakumar Prince; P. Kanagaraj; J. Annie Sheeba; K. Amudha; K. K. Suji; A. Senthil; R. Chandra Babu

    2011-01-01

    Drought stress is a major limitation to rice (Oryza sativa L.) yields and its stability, especially in rainfed conditions. Developing rice cultivars with inherent capacity to withstand\\u000a drought stress would improve rainfed rice production. Mapping quantitative trait loci (QTLs) linked to drought resistance\\u000a traits will help to develop rice cultivars suitable for water-limited environments through molecular marker-assisted selection\\u000a (MAS) strategy.

  3. Development of gene-tagged markers for quantitative trait loci underlying rice yield components

    Microsoft Academic Search

    Chang-Jie Yan; Song Yan; Ya-Chun Yang; Xiu-Hong Zeng; Yu-Wei Fang; Sheng-Yuan Zeng; Chun-Yan Tian; Ya-Wei Sun; Shu-Zhu Tang; Ming-Hong Gu

    2009-01-01

    Higher yields of rice have always been a predominant goal in rice breeding techniques. However, the inheritances of rice yield\\u000a and its components are still unknown, and no information regarding suitable alleles can be directly provided for improving\\u000a the rice yield level until three major quantitative trait loci (QTLs) have been cloned and functionally characterized. These\\u000a QTLs contain Gn1a for

  4. Arctic Ecosystem

    NSDL National Science Digital Library

    2008-01-17

    Despite seemingly inhospitable conditions, the Arctic environment has a vibrant and diverse ecosystem. Explore the life that thrives in this region in this interactive activity adapted from the Woods Hole Oceanographic Institution.

  5. Antarctic Ecosystem

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2008-01-17

    In contrast with its largely lifeless interior, the Antarctic coastal marine environment supports a vibrant and diverse ecosystem. Explore the region's living bounty in this interactive activity adapted from the Woods Hole Oceanographic Institution.

  6. Ecosystem Journalism

    NSDL National Science Digital Library

    Amy Robertson

    2005-11-01

    Third-grade students display their understanding of life science concepts by creating an imaginative newspaper. This creative writing project engages students in researching, writing, and editing a newspaper based on a prairie ecosystem.

  7. Marine Ecosystems

    NSDL National Science Digital Library

    Marine ecosystem introduction to shorelines, temperate oceans, and tropical oceans. Shoreline topics cover sandy and rocky shores, barrier islands, tide pools, estuaries, salt marshes, mud flats, mangrove forests, tides, waves, currents, and shoreline animals. Students can learn about temperate ocean zonation, light, forests, patterns, and animals. The tropical oceans chapter features coral reefs and tropical ocean animals. This site would provide a comprehensive introduction for a marine ecosystems or an ocean science unit.

  8. Elementary Ecosystems

    NSDL National Science Digital Library

    2001-01-01

    This lesson teaches students the basics of species interdependency within an ecosystem. Students describe the things animals need to survive and the ways in which animals depend on other animals and plants; perform a simulation to demonstrate the interdependencies within an ecosystem; look at pictures of endangered animals, and explain what they think might happen to other animals and plants if these animals became extinct; and draw pictures of animals in their natural habitats, and describe what these animals need to survive.

  9. [Dynamics and combined injuries of main pest species in rice cropping zones of Yunnan, Southwest China].

    PubMed

    Dong, Kun; Dong, Yan; Wang, Hai-Long; Zhang, Li-Min; Zan, Qing-An; Chen, Bin; Li, Zheng-Yue

    2014-01-01

    A series of rice pest injuries (due to pathogens, insects, and weeds) were surveyed in 286 farmers' fields for major rice varieties of three rice cropping zones of Yunnan Province, Southwest China. The composition and dynamics of main pest species were analyzed, and the trend of rice pest succession in Yunnan was discussed based upon landmark publications. The results showed that the three rice cropping zones had different pest characteristics as regard to main species, dynamics and combined injuries. Sheath rot, bacterial leaf blight, rice stripe, leaf hoppers, armyworms and stem borers were serious in the japonica rice zone. Sheath blight and rice stripe were serious in the japonica-indica interlacing zone. Leaf blast, sheath blight, leaf folders and weeds above rice crop canopy were serious in the indica rice zone. False smut, plant hoppers and weeds below rice crop canopy were ubiquitous and serious in the three kinds of rice cropping zones. Many kinds of weed infestation emerged in the whole rice cropping seasons. Echinochloa crusgalli, Sagittaria pygmaea, Potamogeton distinctus and Spirodela polyrhiza were the main species of weeds in the rice cropping zones of Yunnan. Overall, levels of combined injuries due to pests in the japonica rice zone and the indica rice zone were higher than that in the japonica-indica interlacing zone. In terms of the trend of rice pest succession in Yunnan, injuries due to false smut, sheath blight and plant hoppers seemed to be in a worse tendency in all rice cropping zones of Yunnan, while dominants species of weeds in the paddy fields are shifting from the annual weeds to the perennial malignant weeds. PMID:24765862

  10. Fine-mapping of qRL6.1 , a major QTL for root length of rice seedlings grown under a wide range of NH 4 + concentrations in hydroponic conditions

    Microsoft Academic Search

    Mitsuhiro Obara; Wataru Tamura; Takeshi Ebitani; Masahiro Yano; Tadashi Sato; Tomoyuki Yamaya

    2010-01-01

    Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients\\u000a more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci\\u000a (QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable\\u000a growth conditions for

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

    PubMed

    Saleh, Mohammed; Meullenet, Jean-Francois

    2015-03-01

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

  12. Genetic, Physiological, and Gene Expression Analyses Reveal That Multiple QTL Enhance Yield of Rice Mega-Variety IR64 under Drought

    PubMed Central

    Swamy B. P., Mallikarjuna; Ahmed, Helal Uddin; Henry, Amelia; Mauleon, Ramil; Dixit, Shalabh; Vikram, Prashant; Tilatto, Ram; Verulkar, Satish B.; Perraju, Puvvada; Mandal, Nimai P.; Variar, Mukund; S., Robin; Chandrababu, Ranganath; Singh, Onkar N.; Dwivedi, Jawaharlal L.; Das, Sankar Prasad; Mishra, Krishna K.; Yadaw, Ram B.; Aditya, Tamal Lata; Karmakar, Biswajit; Satoh, Kouji; Moumeni, Ali; Kikuchi, Shoshi; Leung, Hei; Kumar, Arvind

    2013-01-01

    Background Rice (Oryza sativa L.) is a highly drought sensitive crop, and most semi dwarf rice varieties suffer severe yield losses from reproductive stage drought stress. The genetic complexity of drought tolerance has deterred the identification of agronomically relevant quantitative trait loci (QTL) that can be deployed to improve rice yield under drought in rice. Convergent evidence from physiological characterization, genetic mapping, and multi-location field evaluation was used to address this challenge. Methodology/Principal Findings Two pairs of backcross inbred lines (BILs) from a cross between drought-tolerant donor Aday Sel and high-yielding but drought-susceptible rice variety IR64 were produced. From six BC4F3 mapping populations produced by crossing the +QTL BILs with the ?QTL BILs and IR64, four major-effect QTL - one each on chromosomes 2, 4, 9, and 10 - were identified. Meta-analysis of transcriptome data from the +QTL/?QTL BILs identified differentially expressed genes (DEGs) significantly associated with QTL on chromosomes 2, 4, 9, and 10. Physiological characterization of BILs showed increased water uptake ability under drought. The enrichment of DEGs associated with root traits points to differential regulation of root development and function as contributing to drought tolerance in these BILs. BC4F3-derived lines with the QTL conferred yield advantages of 528 to 1875 kg ha?1 over IR64 under reproductive-stage drought stress in the targeted ecosystems of South Asia. Conclusions/Significance Given the importance of rice in daily food consumption and the popularity of IR64, the BC4F3 lines with multiple QTL could provide higher livelihood security to farmers in drought-prone environments. Candidate genes were shortlisted for further characterization to confirm their role in drought tolerance. Differential yield advantages of different combinations of the four QTL reported here indicate that future research should include optimizing QTL combinations in different genetic backgrounds to maximize yield advantage under drought. PMID:23667521

  13. Phylogeography of Asian wild rice, Oryza rufipogon, reveals multiple independent domestications of cultivated rice, Oryza sativa

    PubMed Central

    Londo, Jason P.; Chiang, Yu-Chung; Hung, Kuo-Hsiang; Chiang, Tzen-Yuh; Schaal, Barbara A.

    2006-01-01

    Cultivated rice, Oryza sativa L., represents the world’s most important staple food crop, feeding more than half of the human population. Despite this essential role in world agriculture, the history of cultivated rice’s domestication from its wild ancestor, Oryza rufipogon, remains unclear. In this study, DNA sequence variation in three gene regions is examined in a phylogeographic approach to investigate the domestication of cultivated rice. Results indicate that India and Indochina may represent the ancestral center of diversity for O. rufipogon. Additionally, the data suggest that cultivated rice was domesticated at least twice from different O. rufipogon populations and that the products of these two independent domestication events are the two major rice varieties, Oryza sativa indica and Oryza sativa japonica. Based on this geographical analysis, O. sativa indica was domesticated within a region south of the Himalaya mountain range, likely eastern India, Myanmar, and Thailand, whereas O. sativa japonica was domesticated from wild rice in southern China. PMID:16766658

  14. Red Yeast Rice: An Introduction

    MedlinePLUS

    ... links Read our disclaimer about external links Menu Red Yeast Rice: An Introduction On this page: Key ... will help ensure coordinated and safe care. About Red Yeast Rice Red yeast rice is made by ...

  15. Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines.

    PubMed

    Gadde, Butchaiah; Bonnet, Sébastien; Menke, Christoph; Garivait, Savitri

    2009-05-01

    Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the world's total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the world's rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries. In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed. PMID:19201513

  16. The use of rice seeds to produce human pharmaceuticals for oral therapy.

    PubMed

    Wakasa, Yuhya; Takaiwa, Fumio

    2013-10-01

    Rice (Oryza sativa L.) is the major staple food consumed by half of the world's population. Rice seeds have gained recent attention as bioreactors for the production of human pharmaceuticals such as therapeutic proteins or peptides. Rice seed production platforms have many advantages over animal cell or microbe systems in terms of cost-effectiveness, scalability, safety, product stability and productivity. Rice seed-based human pharmaceuticals are expected to become innovative therapies as edible drugs. Therapeutic proteins can be sequestered within natural cellular compartments in rice seeds and protected from harsh gastrointestinal environments. This review presents the state-of-the-art on the construction of gene cassettes for accumulation of pharmaceutical proteins or peptides in rice seeds, the generation of transgenic rice plants, and challenges involved in the use of rice seeds to produce human pharmaceuticals. PMID:24092672

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

    PubMed Central

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

    2014-01-01

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

  18. Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, ?-oryzanol, and phytic acid

    PubMed Central

    Goufo, Piebiep; Trindade, Henrique

    2014-01-01

    Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, ?-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of ?-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice. PMID:24804068

  19. Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, ?-oryzanol, and phytic acid.

    PubMed

    Goufo, Piebiep; Trindade, Henrique

    2014-03-01

    Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, ?-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of ?-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice. PMID:24804068

  20. Arsenic speciation in Japanese rice drinks and condiments.

    PubMed

    Signes-Pastor, Antonio J; Deacon, Claire; Jenkins, Richard O; Haris, Parvez I; Carbonell-Barrachina, Angel A; Meharg, Andrew A

    2009-11-01

    Rice has been demonstrated to be one of the major contributors to inorganic arsenic (i-As) intake in humans. However, little is known about rice products as additional source of i-As exposure. In this study, misos, syrups and amazake (a fermented sweet rice drink) produced from rice, barley and millet were analysed for total arsenic (t-As) and a subset of samples were also analyzed for As speciation. Rice based products displayed a higher i-As content than those derived from barley and millet. Most of the t-As in the rice products studied was inorganic (63-83%), the remainder being dimethylarsinic acid. Those who regularly consume rice drinks and condiments, such as the Japanese population and those who follow health conscious diets based on the Japanese cuisine, could reach up to 23% of the World Health Organization's Provisional Tolerable Daily Intake of i-As, by only consuming these kinds of products. This study provides a wide appreciation of how i-As derived from rice based products enters the human diet and how this may be of concern to populations who are already exposed to high levels of i-As through consumption of foods such as rice and seaweed. PMID:19890549

  1. Fat-soluble bioactive components in colored rice varieties.

    PubMed

    Minatel, Igor Otavio; Han, Sang-Ik; Aldini, Giancarlo; Colzani, Mara; Matthan, Nirupa R; Correa, Camila Renata; Fecchio, Denise; Yeum, Kyung-Jin

    2014-10-01

    Bioactive components in rice vary depending on the variety and growing condition. Fat-soluble components such as ?-oryzanol, tocopherols, tocotrienols, carotenoids, and fatty acids were analyzed in brown, sugary brown, red, and black rice varieties using established high-performance liquid chromatography (HPLC) and GC methodologies. In addition, these colored rice varieties were further analyzed using a high-resolution liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (LTQ-Orbitrap XL) to identify the [M-H](-) ions of ?-oryzanol, ranging from m/z 573.3949 to 617.4211. The highest content of tocopherols (?-, 1.5; ?-, 0.5?mg/100?g) and carotenoids (lutein 244; trans-? carotene 25 ?g/100?g) were observed in black rice; tocotrienols (?-, 0.07; ?-, 0.14?mg/100?g) in red rice, and ?-oryzanol (115?mg/100?g) in sugary brown rice. In all colored rice varieties, the major fatty acids were palmitic (16:0), oleic (18:1n-9), and linoleic (18:2n-6) acids. When the ?-oryzanol components were further analyzed by LC-MS/MS, 3, 10, 8, and 8 triterpene alcohols or sterol ferulates were identified in brown, sugary brown, red, and black rice varieties, respectively. Such structural identification can lead to the elucidation of biological function of each component at the molecular level. Consumption of colored rice rich in beneficial bioactive compounds may be a useful dietary strategy for achieving optimal health. PMID:25162990

  2. Biology and epidemiology of rice viruses.

    PubMed

    Hibino, H

    1996-01-01

    The 15 known viruses that occur in rice are rice black-streaked dwarf, rice bunchy stunt, rice dwarf, rice gall dwarf, rice giallume, rice grassy stunt, rice hoja blanca, rice necrosis mosaic, rice ragged stunt, rice stripe necrosis, rice stripe, rice transitory yellowing, rice tungro bacilliform, rice tungro spherical, and rice yellow mottle viruses. This paper describes their geographical distribution, relation to vectors, infection cycles, field dispersal, and development, and lists recorded outbreaks of the viruses. Many rice viruses have become serious problems since rice cultivation has been intensified. Double-cropping of rice using improved, photo-insensitive cultivars of short growth duration has significantly influenced the incidence of these viruses. PMID:15012543

  3. Rice consumption in China

    E-print Network

    Lan, Jin

    1989-01-01

    undertaken to achieve the purpose can be summarized as follows: (a) to provide a description of China, 's rice industry, focusing on the evolution of production, trends in consumption, the structure of the marketing and distribution systems..., and the nature of government policies. (b) to identify important variables that may explain China's rice consumption. The description of China. 's rice industry will serve as background for the main objective of this study which is to develop quantitative...

  4. Mycotoxins in rice

    Microsoft Academic Search

    Kenji Tanaka; Yuki Sago; Yazhi Zheng; Hiroyuki Nakagawa; Masayo Kushiro

    2007-01-01

    Mycotoxin contamination in rice is usually lower as in wheat or corn. However, there are some reports that rice has been contaminated with mycotoxins such as aflatoxin B1, B2, G1, G2 (AFS), citrinin, deoxynivalenol (DON), fumonisin B1, B2, B3 (FMS), fusarenon-X (Fus.-X), nivalenol (NIV), ochratoxin A (OTA), sterigmatocystin (STE), and zearalenone. Rice in Japan is preserved in warehouses where moisture

  5. rice boulevard Tennis Stadium

    E-print Network

    Richards-Kortum, Rebecca

    rice boulevard Jake Hess Tennis Stadium Reckling Park Tennis Courts Practice Field Intramural Field Hess Tennis Stadium, Jake ............34 Holloway Field .................................35 Wendel D

  6. Legislation Affecting the Rice Industry, 1933-56.

    E-print Network

    Kincannon, John A.

    1956-01-01

    . ment in the national economy. This publication reviews major legislation pertaining to rice since the 1933 Agriculture Adjust- ment Act. It cites the major legislative actions taken by the government toward establishing a level of income to rice..., surplus supplies totaled slightly ( over 7 billion pounds from August 1, 1953 to August 1, 1955. The carryover on August 1, 1955 was 23 ' times greater than the carryover of 150 million pounds on August 1, 1952. I The 1956 Agriculture Act represents...

  7. Ecosystem type affects interpretation of soil nematode community measures

    E-print Network

    Neher, Deborah A.

    Ecosystem type affects interpretation of soil nematode community measures D.A. Neher a,*, J. Wu b understanding of performance among major ecosystem types is necessary before nematode community indices can and agricultural ecosystems; (2) compare nematode community composition among and within ecosystem types and report

  8. Coastal Ecosystems

    NSDL National Science Digital Library

    This United States Geological Survey (USGS) report by the Western Ecological Research Center (WERC) highlights Pacific Ocean coastal ecosystems. The website outlines WERC studies that are providing insight into how coastal ecosystems function. The role of sea otters in coastal environments, white abalone (snail) reintroduction, the effects of invasive plants and animals, urban activity, industrial and agricultural pollutants, San Francisco Bay reclamation, population growth, and migratory birds are all investigated in these studies. Fact sheets about certain areas of research are provided for further information.

  9. Diversity of Global Rice Markets and the Science Required for Consumer-Targeted Rice Breeding

    PubMed Central

    Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N. Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D.; Fitzgerald, Melissa

    2014-01-01

    With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a ‘one size fits all’ crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799

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

    PubMed

    Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D; Fitzgerald, Melissa

    2014-01-01

    With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a 'one size fits all' crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799

  11. Additive and additive × additive interaction make important contributions to spikelets per panicle in rice near isogenic (Oryza sativa L.) lines.

    PubMed

    He, Qin; Zhang, Kexin; Xu, Caiguo; Xing, Yongzhong

    2010-12-01

    Epistasis plays an important role in the genetic basis of rice yield traits. Taking interactions into account in breeding programs will help the development of high-yielding rice varieties. In this study, three sets of near isogenic lines (NILs) targeting three QTLs for spikelets per panicle (SPP), namely qSPP1, qSPP2 and qSPP7, which share the same Zhenshan 97 genetic background, were used to produce an F(2) population in which the three QTLs segregated simultaneously. The genotypes of the individual F(2) plants at the three QTLs were replaced with three markers that are closely linked to the corresponding QTLs. These QTLs were validated in the F(2) and F(3) populations at the single marker level. qSPP7 exhibited major pleiotropic effects on SPP, plant height and heading date. Multifactor analysis of variance was performed for the F(2) population and its progeny. Additive (additive interaction between qSPP2 and qSPP7 had significant effects on SPP in both the F(2) population and its progeny. Both additive and additive (additive interactions could explain about 73% of the total SPP phenotypic variance. The SPP performance of 27 three-locus combinations was ranked and favorable combinations were recommended for rice breeding in different ecosystems. PMID:21193158

  12. Rice Cluster I, an Important Group of Archaea Producing Methane in Rice Fields

    NASA Astrophysics Data System (ADS)

    Conrad, R.

    2006-12-01

    Rice fields are an important source for the greenhouse gas methane. Methane is a major degradation product of organic matter in the anoxic soil, is partially oxidized in the rhizosphere and is emitted into the atmosphere through the aerenchyma system of the plants. Anaerobic degradation of organic matter by fermenting bacteria eventually results in the production of acetate and hydrogen, the two major substrates for microbial methanogenesis. The community of methanogenic archaea consists of several major orders or families including hydrogen-utilizing Rice Cluster-I (RC-I). Environmental conditions affect the methanogenic degradation process and the community structure of the methanogenic archaea in soil and rhizosphere. For example, populations of acetoclastic Methanosaetaceae and Methanosarcinaceae are enhanced by low and high acetate concentrations, respectively. Stable isotope probing of 16S rRNA showed that RC-I methanogens are mainly active on rice roots and at low H2 concentrations. Growth and population size is largely consistent with energetic conditions. RC-I methanogens on roots seem to be responsible for methane production from plant photosynthates that account for a major part of the emitted methane. Populations of RC-I methanogens in rice field soil are also enhanced at elevated temperatures (40-50°C). Moderately thermophilic members of RC-I methanogens or other methanogenic families were found to be ubiquitously present in soils from rice fields and river marshes. The genome of a RC-I methanogen was completely sequenced out of an enrichment culture using a metagenome approach. Genes found are consistent with life in the rhizosphere and in temporarily drained, oxic soil. We found that the methanogenic community structure on the rice roots is mainly determined by the respective community structure of the soil, but is in addition affected by the rice cultivar. Rice microcosms in which soil and rice roots are mainly colonized by RC-I methanogens produce and emit more methane than when inhabited by Methanomicrobiales, indicating that the methanogenic archaeal community is an important factor for methane emission from rice fields.

  13. Project RICE (Responsive Inner City Education).

    ERIC Educational Resources Information Center

    Mattai, P. Rudy

    Project RICE (Responsive Inner City Education) prepared a cadre of 36 teachers drawn from majority and minority populations in 3 inner-city schools in Buffalo (New York) to complement mastery of subject matter with appropriate pedagogical styles. The project was designed to test the hypothesis that minority students in inner-city schools do not…

  14. Global efforts in managing rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease caused by the fungus Magnaporthe oryzae is a major destructive disease threatening global food security. Resistance (R) genes to M. oryzae are effective in preventing infections by strains of M. oryzae carry the corresponding avirulence (AVR) genes. Effectiveness of genetic resist...

  15. SFRSF: Our Coastal Ecosystems

    NSDL National Science Digital Library

    This South Florida Restoration Science Forum (SFRSF) page highlights the coastal ecosystems of southern Florida. Research displayed from poster presentations covers the coastal area habitats, sustaining and enhancing coastal waters, major coastal challenges, restoring and enhancing estuaries, and using science for effective resource management. The six estuaries discussed are the Caloosahatchee, Southwest Florida, Biscayne Bay, Florida Bay, Florida Keys, and St. Lucie estuaries. Specific issues concerning each estuary are covered, and links are provided for additional information.

  16. EXIT INTERVIEW SUMMARY FORM Life after Rice...

    E-print Network

    Richards-Kortum, Rebecca

    1 EXIT INTERVIEW SUMMARY FORM Life after Rice... Rice ID: _____________________ * Medical benefits - Your Rice medical benefits will end on: __________________________ * Vesting in the 401(a) Rice. * Rice retiree - If you qualify as a Rice retiree, in accordance with the Rice University Human Resources

  17. Desert Ecosystems

    NSDL National Science Digital Library

    The Desert Ecosystems site describes the geology and climate, plants and animals, and cultural history of the main U.S. desert regions including: the Mojave Desert, the Great Basin, and the Colorado/Sonoran desert. There are also descriptions and photos of water in the desert, coyotes, the desert tortoise, and the creosote bush.

  18. Long-Term Ecosystem Response to the Exxon Valdez Oil Spill

    E-print Network

    Long-Term Ecosystem Response to the Exxon Valdez Oil Spill Charles H. Peterson,1 * Stanley D. Rice The ecosystem response to the 1989 spill of oil from the Exxon Valdez into Prince William Sound, Alaska, shows long-term risks and impacts. B efore the Exxon Valdez oil spill, infor- mation available

  19. Modeling the Effects of Water Temperature on Rice Growth and Yield under a Cool Climate: I. Model Development

    Microsoft Academic Search

    Hiroyuki Shimono; Toshihiro Hasegawa; Kazuto Iwama

    For paddy rice (Oryza sativa L.), water temperature (Tw) is a major determinant of growth and yield. In rice paddies, Tw is higher than the air temperature (Ta), and this difference significantly affects produc- tion, especially in cool climates. However, there is no model to eval- uate the effects of Tw on rice yield. To simulate temporal and regional differences

  20. Distribution of the African rice gall midge, Orseolia oryzivora Harris and Gagné and its parasitoids in Nigeria

    Microsoft Academic Search

    M. N. Ukwungwu; R. C. Joshi

    1992-01-01

    The African rice gall midge, Orseolia oryzivora Harris and Gagné has become one of the major biotic constraints to rice production in Nigeria. A survey of gall midge distribution in Nigeria showed that the pest was common in the savannah and forest zones on rice grown under lowland ecologies. Endemic areas were identified which could serve as ‘hot spots’ for

  1. Elemental-composition and plant-trait patterns in an ionomically and genetically diverse set of rice germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With about half of the worlds people dependent on rice as their main food source, improving the nutritional value of rice could have major impact on human health. The first step toward breeding rice cultivars with enhanced element composition (ionomics) is to understand the genetic diversity availab...

  2. Identification of rice blast resistant gene Pi-z(t) in NSGC using DNA markers and pathogenicity assays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast disease, caused by the fungus Magnaporthe oryzae (formerly Magnaporthe grisea) is a major fungal disease threatening rice production worldwide. Genetic resistance in rice to M. oryzae typically belongs to a classic gene-for-gene system where a resistance (R) gene is effective in preventin...

  3. Rice bran: a novel functional ingredient.

    PubMed

    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 ?-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 neglected ingredients under various headings. PMID:24345050

  4. Digital Ecosystems: Ecosystem-Oriented Architectures

    Microsoft Academic Search

    Gerard Briscoe; Suzanne Sadedin; Philippe De Wilde

    2011-01-01

    We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation\\u000a of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software\\u000a applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems,\\u000a where the optimisation works at two levels: a first optimisation, migration

  5. Induced mutations in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induced mutations have a long history in both applied and basic aspects of rice research. During the past fifty years, over 500 rice varieties have been developed worldwide, either directly from induced mutants or as a result of crossing such mutants with other breeding lines. More recently, the gen...

  6. Registration of 'Cybonnet' Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Virus Resistance in Rice

    Microsoft Academic Search

    D. Fargette; A. Ghesquière; L. Albar; J. M. Thresh

    The genus Oryza of the Family Gramineae comprises 18 tropical and subtropical species, of which two species are cultivated as rice: O. sativa and O. glaberrima. Rice provides the staple food of 60% of mankind, and is cultivated in all tropical and subtropical countries. Oryza sativa is thought to have been domesticated in China before 6500 BC, in India between

  8. QTL mapping in rice

    Microsoft Academic Search

    Susan R. McCough; Rebecca W. Doerge

    1995-01-01

    In the past 10 years, interest in applying the tools of molecular genetics to the problem of increasing world rice production has resulted in the generation of two highly saturated, molecular linkage maps of rice, and the localization of numerous genes and quantitative trait loci (QTLs). Primary studies have identified QTLs associated with disease resistance, abiotic stress tolerance and yield

  9. Rice University GeneralAnnouncements

    E-print Network

    Richards-Kortum, Rebecca

    Rice University GeneralAnnouncements 2001­2002 #12;NOTE: This catalog represents the most accurate without notice. William Marsh Rice University Physical Address: 6100 Main Street, Houston, Texas 77005 Address: http://www.rice.edu 2001­2002 General Announcements online: http://www.ruf.rice

  10. Rice University GeneralAnnouncements

    E-print Network

    Richards-Kortum, Rebecca

    Rice University GeneralAnnouncements 2002­2003 #12;NOTE: This catalog represents the most accurate without notice. William Marsh Rice University Physical Address: 6100 Main Street, Houston, Texas 77005 Address: http://www.rice.edu 2001­2002 General Announcements online: http://www.ruf.rice

  11. Rice University GeneralAnnouncements

    E-print Network

    Richards-Kortum, Rebecca

    Rice University GeneralAnnouncements 2003­2004 #12;NOTE: This catalog represents the most accurate without notice. William Marsh Rice University Physical Address: 6100 Main Street, Houston, Texas 77005 Address: http://www.rice.edu 2003­2004 General Announcements online: http://www.rice.edu/catalog/ Please

  12. Bioengineering nitrogen acquisition in rice

    E-print Network

    Britto, Dev T.

    Bioengineering nitrogen acquisition in rice: can novel initiatives in rice genomics and physiology contribute to global food security? Dev T. Britto and Herbert J. Kronzucker* Summary Rice is the most and expansion of arable land have massively increased global rice production, enabling crop scientists

  13. Information: Rice Young Alumni Information

    E-print Network

    Palem, Krishna V.

    Rice Young Alumni Detailed Information: Houston Events 2011-2012 #12; Rice Young Alumni Information Alumni.rice.edu 2 Join the Parliament in HoustonHouston Young Alumni Events This page to this site for more information and visit our Rice Young Alumni Houston Facebook page for special details

  14. Rice blast disease in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Methylated arsenic species in rice: geographical variation, origin, and uptake mechanisms.

    PubMed

    Zhao, Fang-Jie; Zhu, Yong-Guan; Meharg, Andrew A

    2013-05-01

    Rice is a major source of inorganic arsenic (iAs) in the human diet because paddy rice is efficient at accumulating As. Rice As speciation is dominated by iAs and dimethylarsinic acid (DMA). Here we review the global pattern in rice As speciation and the factors causing the variation. Rice produced in Asia shows a strong linear relationship between iAs and total As concentration with a slope of 0.78. Rice produced in Europe and the United States shows a more variable, but generally hyperbolic relationship with DMA being predominant in U.S. rice. Although there is significant genotypic variation in grain As speciation, the regional variations are primarily attributed to environmental factors. Emerging evidence also indicates that methylated As species in rice are derived from the soil, while rice plants lack the As methylation ability. Soil flooding and additions of organic matter increase microbial methylation of As, although the microbial community responsible for methylation is poorly understood. Compared with iAs, methylated As species are taken up by rice roots less efficiently but are transported to the grain much more efficiently, which may be an important factor responsible for the spikelet sterility disorder (straight-head disease) in rice. DMA is a weak carcinogen, but the level of ingestion from rice consumption is much lower than that of concern. Questions that require further investigations are identified. PMID:23521218

  16. Climate change: implications for the yield of edible rice.

    PubMed

    Zhao, Xiangqian; Fitzgerald, Melissa

    2013-01-01

    Global warming affects not only rice yield but also grain quality. A better understanding of the effects of climate factors on rice quality provides information for new breeding strategies to develop varieties of rice adapted to a changing world. Chalkiness is a key trait of physical quality, and along with head rice yield, is used to determine the price of rice in all markets. In the present study, we show that for every ?1% decrease in chalkiness, an increase of ?1% in head rice yield follows, illustrating the dual impact of chalk on amount of marketable rice and its value. Previous studies in controlled growing conditions report that chalkiness is associated with high temperature. From 1980-2009 at IRRI, Los Baños, the Philippines, annual minimum and mean temperatures, and diurnal variation changed significantly. The objective of this study was to determine how climate impacts chalkiness in field conditions over four wet and dry seasons. We show that low relative humidity and a high vapour pressure deficit in the dry season associate with low chalk and high head rice yield in spite of higher maximum temperature, but in the opposite conditions of the wet season, chalk is high and head rice yield is low. The data therefore suggest that transpirational cooling is a key factor affecting chalkiness and head rice yield, and global warming per se might not be the major factor that decreases the amount and quality of rice, but other climate factors in combination, that enable the crop to maintain a cool canopy. PMID:23776635

  17. Climate Change: Implications for the Yield of Edible Rice

    PubMed Central

    Zhao, Xiangqian; Fitzgerald, Melissa

    2013-01-01

    Global warming affects not only rice yield but also grain quality. A better understanding of the effects of climate factors on rice quality provides information for new breeding strategies to develop varieties of rice adapted to a changing world. Chalkiness is a key trait of physical quality, and along with head rice yield, is used to determine the price of rice in all markets. In the present study, we show that for every ?1% decrease in chalkiness, an increase of ?1% in head rice yield follows, illustrating the dual impact of chalk on amount of marketable rice and its value. Previous studies in controlled growing conditions report that chalkiness is associated with high temperature. From 1980–2009 at IRRI, Los Baños, the Philippines, annual minimum and mean temperatures, and diurnal variation changed significantly. The objective of this study was to determine how climate impacts chalkiness in field conditions over four wet and dry seasons. We show that low relative humidity and a high vapour pressure deficit in the dry season associate with low chalk and high head rice yield in spite of higher maximum temperature, but in the opposite conditions of the wet season, chalk is high and head rice yield is low. The data therefore suggest that transpirational cooling is a key factor affecting chalkiness and head rice yield, and global warming per se might not be the major factor that decreases the amount and quality of rice, but other climate factors in combination, that enable the crop to maintain a cool canopy. PMID:23776635

  18. Rice transgene flow: its patterns, model and risk management.

    PubMed

    Jia, Shirong; Yuan, Qianhua; Pei, Xinwu; Wang, Feng; Hu, Ning; Yao, Kemin; Wang, Zhixing

    2014-12-01

    Progress has been made in a 12 year's systemic study on the rice transgene flow including (i) with experiments conducted at multiple locations and years using up to 21 pollen recipients, we have elucidated the patterns of transgene flow to different types of rice. The frequency to male sterile lines is 10(1) and 10(3) higher than that to O. rufipogon and rice cultivars. Wind speed and direction are the key meteorological factors affecting rice transgene flow. (ii) A regional applicable rice gene flow model is established and used to predict the maximum threshold distances (MTDs) of gene flow during 30 years in 993 major rice producing counties of southern China. The MTD0.1% for rice cultivars is basically ?5 m in the whole region, despite climate differs significantly at diverse locations and years. This figure is particularly valuable for the commercialization and regulation of transgenic rice. (iii) The long-term fate of transgene integrated into common wild rice was investigated. Results demonstrated that the F1 hybrids of transgenic rice/O. rufipogon gradually disappeared within 3-5 years, and the Bt or bar gene was not detectable in the mixed population, suggesting the O. rufipogon may possess a strong mechanism of exclusiveness for self-protection. (iv) The flowering time isolation and a 2-m-high cloth-screen protection were proved to be effective in reducing transgene flow. We have proposed to use a principle of classification and threshold management for different types of rice. PMID:25431202

  19. Use of Amphibians as Indicators of Ecosystem Restoration Success1

    E-print Network

    Mazzotti, Frank

    CIR 1484 Use of Amphibians as Indicators of Ecosystem Restoration Success1 Ken G. Rice, Frank J. Nick T. Place, dean for UF/IFAS Extension. Introduction There are 18 native amphibians in southern Florida (Figures 2 and 5). Amphibians are found in virtually all habitats from pine forests to sawgrass

  20. The Vehicle Ecosystem

    NASA Astrophysics Data System (ADS)

    Kuschel, Jonas

    Ubiquitous computing in the vehicle industry has primarily focused on sensor data serving different ubiquitous on-board services (e.g., crash detection, antilock brake systems, or air conditioning). These services mainly address vehicle drivers while driving. However, in view of the role of vehicles in today's society, it goes without saying that vehicles relate to more than just the driver or occupants; they are part of a larger ecosystem, including traffic participants, authorities, customers and the like. To serve the ecosystem with ubiquitous services based on vehicle sensor data, there is a need for an open information infrastructure that enables service development close to the customer. This paper presents results from a research project on designing such an infrastructure at a major European vehicle manufacturer. Our empirical data shows how the vehicle manufacturer's conceptualization of services disagrees with the needs of vehicle stakeholders in a more comprehensive vehicle ecosystem. In light of this, we discuss the effect on information infrastructure design and introduce the distinction between information infrastructure as product feature and service facilitator. In a more general way, we highlight the importance of information infrastructure to contextualize the vehicle as part of a larger ecosystem and thus support open innovation.

  1. Genetic diversity and disease control in rice.

    PubMed

    Zhu, Y; Chen, H; Fan, J; Wang, Y; Li, Y; Chen, J; Fan, J; Yang, S; Hu, L; Leung, H; Mew, T W; Teng, P S; Wang, Z; Mundt, C C

    2000-08-17

    Crop heterogeneity is a possible solution to the vulnerability of monocultured crops to disease. Both theory and observation indicate that genetic heterogeneity provides greater disease suppression when used over large areas, though experimental data are lacking. Here we report a unique cooperation among farmers, researchers and extension personnel in Yunnan Province, China--genetically diversified rice crops were planted in all the rice fields in five townships in 1998 and ten townships in 1999. Control plots of monocultured crops allowed us to calculate the effect of diversity on the severity of rice blast, the major disease of rice. Disease-susceptible rice varieties planted in mixtures with resistant varieties had 89% greater yield and blast was 94% less severe than when they were grown in monoculture. The experiment was so successful that fungicidal sprays were no longer applied by the end of the two-year programme. Our results support the view that intraspecific crop diversification provides an ecological approach to disease control that can be highly effective over a large area and contribute to the sustainability of crop production. PMID:10963595

  2. Rice research for food security and sustainable agricultural development in Asia: Achievements and future challenges

    Microsoft Academic Search

    K. S. Fischer

    1995-01-01

    Rice is the major staple food of Asia, and an important source of employment and income in rural areas, particularly in low-income countries. Research has contributed significantly in achieving food security by increasing the yield potential of rice in irrigated systems, reducing the crop maturity period and achieving yield stability by developing resistance against major insects and diseases in the

  3. RNAi suppression of rice endogenous storage proteins enhances the production of rice-based Botulinum neutrotoxin type A vaccine.

    PubMed

    Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Hiroiwa, Tomoko; Kong, Il Gyu; Kuroda, Masaharu; Takahashi, Yoko; Nochi, Tomonori; Tokuhara, Daisuke; Kohda, Tomoko; Kozaki, Shunji; Kiyono, Hiroshi

    2012-06-13

    Mucosal vaccines based on rice (MucoRice) offer a highly practical and cost-effective strategy for vaccinating large populations against mucosal infections. However, the limitation of low expression and yield of vaccine antigens with high molecular weight remains to be overcome. Here, we introduced RNAi technology to advance the MucoRice system by co-introducing antisense sequences specific for genes encoding endogenous rice storage proteins to minimize storage protein production and allow more space for the accumulation of vaccine antigen in rice seed. When we used RNAi suppression of a combination of major rice endogenous storage proteins, 13 kDa prolamin and glutelin A in a T-DNA vector, we could highly express a vaccine comprising the 45 kDa C-terminal half of the heavy chain of botulinum type A neurotoxin (BoHc), at an average of 100 ?g per seed (MucoRice-BoHc). The MucoRice-Hc was water soluble, and was expressed in the cytoplasm but not in protein body I or II of rice seeds. Thus, our adaptation of the RNAi system improved the yield of a vaccine antigen with a high molecular weight. When the mucosal immunogenicity of the purified MucoRice-BoHc was examined, the vaccine induced protective immunity against a challenge with botulinum type A neurotoxin in mice. These findings demonstrate the efficiency and utility of the advanced MucoRice system as an innovative vaccine production system for generating highly immunogenic mucosal vaccines of high-molecular-weight antigens. PMID:22554467

  4. Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from

    E-print Network

    Richards-Kortum, Rebecca

    189 Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from all disciplines build their leadership capacities to create and manage change ef- fectively. Leadership Rice explores how heart and mind, theory and practice, and ideas and actions come together

  5. Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain

    E-print Network

    Richards-Kortum, Rebecca

    Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain leadership roles at Rice and beyond. We provide leadership development opportunities to undergraduates from every ambition for leadership. We seek to accomplish our mission through a blend of curricular and co

  6. Fine-mapping of qRL6.1, a major QTL for root length of rice seedlings grown under a wide range of NH4+ concentrations in hydroponic conditions

    PubMed Central

    Tamura, Wataru; Ebitani, Takeshi; Yano, Masahiro; Sato, Tadashi; Yamaya, Tomoyuki

    2010-01-01

    Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci (QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’, a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 ?M NH4+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL, qRL6.1, greatly promoted root elongation under all NH4+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1328-3) contains supplementary material, which is available to authorized users. PMID:20390245

  7. Introducing non-flooded crops in rice-dominated landscapes: Impact on carbon, nitrogen and water budgets

    NASA Astrophysics Data System (ADS)

    Jauker, Frank; Wassmann, Reiner; Amelung, Wulf; Breuer, Lutz; Butterbach-Bahl, Klaus; Conrad, Ralf; Ekschmitt, Klemens; Goldbach, Heiner; He, Yao; John, Katharina; Kiese, Ralf; Kraus, David; Reinhold-Hurek, Barbara; Siemens, Jan; Weller, Sebastian; Wolters, Volkmar

    2013-04-01

    Rice production consumes about 30% of all freshwater used worldwide and 45% in Asia. Turning away from permanently flooded rice cropping systems for mitigating future water scarcity and reducing methane emissions, however, will alter a variety of ecosystem services with potential adverse effects to both the environment and agricultural production. Moreover, implementing systems that alternate between flooded and non-flooded crops increases the risk of disruptive effects. The multi-disciplinary DFG research unit ICON aims at exploring and quantifying the ecological consequences of altered water regimes (flooded vs. non-flooded), crop diversification (irrigated rice vs. aerobic rice vs. maize), and different fertilization strategies (conventional, site-specific, and zero N fertilization). ICON particularly focuses on the biogeochemical cycling of carbon and nitrogen, green-house gas (GHG) emissions, water balance, soil biotic processes and other important ecosystem services. The overarching goal is to provide the basic process understanding that is necessary for balancing the revenues and environmental impacts of high-yield rice cropping systems while maintaining their vital ecosystem services. To this aim, a large-scale field experiment has been established at the experimental farm of the International Rice Research Institute (IRRI, Philippines). Ultimately, the experimental results are analyzed in the context of management scenarios by an integrated modeling of crop development (ORYZA), carbon and nitrogen cycling (MoBiLE-DNDC), and water fluxes (CMF), providing the basis for developing pathways to a conversion of rice-based systems towards higher yield potentials under minimized environmental impacts. In our presentation, we demonstrate the set-up of the controlled large-scale field experiment for simultaneous assessment of carbon and nitrogen fluxes and water budgets. We show and discuss first results for: - Quantification and assessment of the net-fluxes of CH4, N2O and CO2 from rice-rice and rice-maize rotations. The conversion of flooded to non-flooded cropping systems resulted in pollution swapping of greenhouse gas emissions, shifting from CH4 under wet conditions to N2O under dry conditions. - Quantification and assessment of water budgets and nutrient loss in rice-rice and rice-maize rotations. Switching from rice-rice dominated growing systems to upland rice or maize-rice cropping systems resulted in reduced water use efficiency and increased nitrogen loss. - Quantification and assessment of soil functions affected by soil fauna community structure in flooded and non-flooded cropping rotations. In contrast to temperate soils, earthworms reduced the peaks of microbial C and N decomposition depending on soil water content.

  8. Rice-based oral antibody fragment prophylaxis and therapy against rotavirus infection

    PubMed Central

    Tokuhara, Daisuke; ?lvarez, Beatriz; Mejima, Mio; Hiroiwa, Tomoko; Takahashi, Yuko; Kurokawa, Shiho; Kuroda, Masaharu; Oyama, Masaaki; Kozuka-Hata, Hiroko; Nochi, Tomonori; Sagara, Hiroshi; Aladin, Farah; Marcotte, Harold; Frenken, Leon G.J.; Iturriza-Gómara, Miren; Kiyono, Hiroshi; Hammarström, Lennart; Yuki, Yoshikazu

    2013-01-01

    Rotavirus-induced diarrhea is a life-threatening disease in immunocompromised individuals and in children in developing countries. We have developed a system for prophylaxis and therapy against rotavirus disease using transgenic rice expressing the neutralizing variable domain of a rotavirus-specific llama heavy-chain antibody fragment (MucoRice-ARP1). MucoRice-ARP1 was produced at high levels in rice seeds using an overexpression system and RNAi technology to suppress the production of major rice endogenous storage proteins. Orally administered MucoRice-ARP1 markedly decreased the viral load in immunocompetent and immunodeficient mice. The antibody retained in vitro neutralizing activity after long-term storage (>1 yr) and boiling and conferred protection in mice even after heat treatment at 94°C for 30 minutes. High-yield, water-soluble, and purification-free MucoRice-ARP1 thus forms the basis for orally administered prophylaxis and therapy against rotavirus infections. PMID:23925294

  9. The Potential of Polarimetric and Compact SAR Data in Rice Identification

    NASA Astrophysics Data System (ADS)

    Shao, Y.; Li, K.; Brisco, B.; Liu, L.; Yang, Z.

    2014-03-01

    Rice is a major food staple in the world, and provides food for more than one-third of the global population. The monitoring and mapping of paddy rice in a timely and efficient manner is very important for governments and decision makers. Synthetic Aperture Radar (SAR) has been proved to be a significant data source in rice monitoring. In this study, RADARSAT-2 polarimetric data were used to simulate compact polarimetry data. The simulated compact data and polarimetric data were then used to evaluate the information content for rice identification. The results indicate that polarimetric SAR can be used for rice identification based on the scattering mechanisms. The compact polarization RH and the RH/RL ratio are very promising for the discrimination of transplanted rice and direct-sown rice. These results require verification in further research.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2011-12-13

    For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice-fish coculture (RF), which has been designated a "globally important agricultural heritage system," has been maintained for over 1,200 y in south China. A field survey demonstrated that although rice yield and rice-yield stability are similar in RF and rice monoculture (RM), RF requires 68% less pesticide and 24% less chemical fertilizer than RM. A field experiment confirmed this result. We documented that a mutually beneficial relationship between rice and fish develops in RF: Fish reduce rice pests and rice favors fish by moderating the water environment. This positive relationship between rice and fish reduces the need for pesticides in RF. Our results also indicate a complementary use of nitrogen (N) between rice and fish in RF, resulting in low N fertilizer application and low N release into the environment. These findings provide unique insights into how positive interactions and complementary use of resource between species generate emergent ecosystem properties and how modern agricultural systems might be improved by exploiting synergies between species. PMID:22084110

  12. Rapid Recovery of Damaged Ecosystems

    PubMed Central

    Jones, Holly P.; Schmitz, Oswald J.

    2009-01-01

    Background Recent reports on the state of the global environment provide evidence that humankind is inflicting great damage to the very ecosystems that support human livelihoods. The reports further predict that ecosystems will take centuries to recover from damages if they recover at all. Accordingly, there is despair that we are passing on a legacy of irreparable damage to future generations which is entirely inconsistent with principles of sustainability. Methodology/Principal Findings We tested the prediction of irreparable harm using a synthesis of recovery times compiled from 240 independent studies reported in the scientific literature. We provide startling evidence that most ecosystems globally can, given human will, recover from very major perturbations on timescales of decades to half-centuries. Significance/Conclusions Accordingly, we find much hope that humankind can transition to more sustainable use of ecosystems. PMID:19471645

  13. THE RICE KINASE DATABASE (RKD): A PHYLOGENOMIC DATABASE FOR THE RICE KINOME

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rice genome contains 1,429 protein kinases, the vast majority of which have unknown functions. We created a phylogenomic database (http://rkd.ucdavis.edu) to facilitate functional analysis of this large gene family. Sequence and genomic data, including gene expression data and protein-protein ...

  14. Retrieving canopy height and density of paddy rice from Radarsat-2 images with a canopy scattering model

    NASA Astrophysics Data System (ADS)

    Zhang, Yuan; Liu, Xiaohui; Su, Shiliang; Wang, Cuizhen

    2014-05-01

    Quantification of rice biophysical properties is important not only for rice growth monitoring and cropping management, but for understanding carbon cycle in agricultural ecosystems. In this study, a rice canopy scattering model (RCSM) was firstly utilized to simulate rice backscatter with a root mean square error (RMSE) <1 dB in comparison with the C-band, HH-polarization Radarsat-2 images. And then, by integrating the model with a generic algorithm optimization tools (GOAT), canopy height and density were separately retrieved from Radarsat-2 images acquired in three rice growth stages (elongation stage, heading stage and yellow ripening stage). Accuracy analysis showed that the two parameters could be retrieved with the RMSE of 5.4 cm in height, and 26 (#/m2) in density. The study demonstrated the potential of Radarsat-2 SAR data for quantitative mapping of biophysical parameters of paddy rice.

  15. Innate immunity in rice

    PubMed Central

    Chen, Xuewei; Ronald, Pamela C.

    2011-01-01

    Advances in studies of rice innate immunity have led to the identification and characterization of host sensors encoding receptor kinases that perceive conserved microbial signatures. The non-RD domain, a newly recognized hallmark of these receptor kinases is highly expanded in rice (Oryza sativa) compared with Arabidopsis (Arabidopsis thaliana). Researchers have also identified a diverse array of microbial effectors from bacterial and fungal pathogens that triggers immune responses upon perception. These include both, effectors that indirectly target host Nucleotide binding site/Leucine rice repeat (NBS-LRR) proteins and transcription activator-like (TAL) effectors that directly bind promoters of host genes. Here we review the recognition and signaling events that govern rice innate immunity. PMID:21602092

  16. Rice (Oryza sativa) allergy in rhinitis and asthma patients: a clinico-immunological study.

    PubMed

    Kumar, Raj; Srivastava, Prakriti; Kumari, Dolly; Fakhr, Hena; Sridhara, S; Arora, Naveen; Gaur, S N; Singh, B P

    2007-01-01

    Sensitization to foods varies in different countries reflecting a possible interaction of genetic factors, cultural and dietary habits. Rice is a major food consumed world wide and needs evaluation for IgE mediated reactions. The present study was carried out to identify rice allergy in patients of rhinitis and asthma and identify the allergenic proteins in raw and cooked rice. Of 1200 patients screened using standard questionnaire, 165 presented with history of rice allergy. Of these, 20 (12.1%) patients demonstrated marked positive skin prick test (SPT) and 13 showed significantly raised specific IgE to rice compared to normal controls. Double blind placebo controlled food challenge (DBPCFC) confirmed rice allergy in 6/10 patients. Immunoblot with hypersensitive individual patients' sera showed 14-16, 33, 56 and 60 kDa proteins as major IgE-binding components in rice. Boiled rice retained four IgE reactive proteins of 16, 23, 33 and 53 kDa. In summary, IgE-mediated rice allergy affects 0.8% [(0.42-1.58) at 95% CI] of asthma and rhinitis cases. The subjects with severe SPT reactions (4 mm or above) and specific IgE, 6.9 ng/ml to rice demonstrated positive blinded food challenge with clinical symptoms. PMID:17336834

  17. Biodiversity regulates ecosystem predictability

    Microsoft Academic Search

    Jill McGrady-Steed; Patricia M. Harris; Peter J. Morin

    1997-01-01

    Links between biodiversity and ecosystem function provide compelling reasons for conserving maximal numbers of species in ecosystems. Here we describe a previously unrecognized effect of biodiversity on ecosystem predictability, where predictability is inversely related to temporal and spatial variation in ecosystem properties. By manipulating biodiversity in aquatic microbial communities, we show that one process, ecosystem respiration, becomes more predictable as

  18. Mapping of QTLs for phosphorus-deficiency tolerance in rice (Oryza sativa L.)

    Microsoft Academic Search

    M. Wissuwa; M. Yano; N. Ae

    1998-01-01

    Phosphorus (P) deficiency of soils is a major yield-limiting factor in rice production. Increasing the P-deficiency tolerance\\u000a of rice cultivars may represent a more cost-effective solution than relying on fertilizer application. The objective of this\\u000a study was to identify putative QTLs for P-deficiency tolerance in rice, using 98 backcross inbred lines derived from a japonica?indica cross and genotyped at 245

  19. Economic and Constraint Analysis of Rice Cultivation in Kaithal District of Haryana

    Microsoft Academic Search

    B. Nirmala; P. Muthuraman

    A study on economics and major constraints in rice cultivation in Kaithal district of Haryana was conducted during 2007-08. The study covered four villages of two blocks and data on constraints and cost-return aspects of rice cultivation were collected from 80 farmers. Total costs in rice production amounted to be Rs. 33778.68\\/ha. Average yield was 4.99 t\\/ha. Benefit-cost ratio worked

  20. Leadership Rice The mission of Leadership RiceistohelpRiceUniversityundergraduates

    E-print Network

    Richards-Kortum, Rebecca

    189 Leadership Rice The mission of Leadership RiceistohelpRiceUniversityundergraduates fromalldisciplinesbuildtheirleadershipcapacitiestocreateandmanage changeeffectively.LeadershipRiceexploreshowheartandmind,theoryand practice,andideasandactionscometogethertofacilitatechange. Theintroductorycourse,LEAD309Leadership: Theory to Practice (formerly UNIV309),isrequiredtoapplyforparticipationinthe

  1. Regime shifts in the Humboldt Current ecosystem

    Microsoft Academic Search

    Jürgen Alheit; Miguel Niquen

    2004-01-01

    Of the four major eastern boundary currents, the Humboldt Current (HC) stands out because it is extremely productive, dominated by anchovy dynamics and subject to frequent direct environmental perturbations of the El Niño Southern Oscillation (ENSO). The long-term dynamics of the HC ecosystem are controlled by shifts between alternating anchovy and sardine regimes that restructure the entire ecosystem from phytoplankton

  2. PRESERVING BIODIVERSITY: SPECIES, ECOSYSTEMS, OR LANDSCAPES?

    Microsoft Academic Search

    JERRY F. FRANKLIN

    1993-01-01

    Efforts to preserve biological diversity must focus increasingly at the ecosystem level because of the immense number of species, the majority of which are currently unknown. An ecosystem approach is also the only way to conserve processes and habitats (such as forest canopies, belowground habitats, and hyporheic zones) that, with their constituent species, are poorly known. Continued concern with species

  3. Chesapeake Bay: Introduction to an Ecosystem.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    The Chesapeake Bay is the largest estuary in the contiguous United States. The Bay and its tidal tributaries make up the Chesapeake Bay ecosystem. This document, which focuses of various aspects of this ecosystem, is divided into four major parts. The first part traces the geologic history of the Bay, describes the overall physical structure of…

  4. The Belgian sandy beach ecosystem: a review

    Microsoft Academic Search

    Jeroen Speybroeck; Dries Bonte; Wouter Courtens; Tom Gheskiere; Patrick Grootaert; Jean-Pierre Maelfait; Sam Provoost; Koen Sabbe; Eric W. M. Stienen; Vera Van Lancker; Wouter Van Landuyt; Magda Vincx; Steven Degraer

    2008-01-01

    This paper reviews the available knowledge on sedimentology, hydrodynamics and five major ecosystem components (microphytobenthos, vascular plants, terrestrial arthropods, zoobenthos, and avifauna) of Belgian sandy beaches. It covers the area from the foredunes to the lower foreshore, takes an ecosystem approach to beaches of this specific geographic area. Morphodynamically, Bel- gian beaches are (ultra-)dissipative, macrotidal, and wide. Characteristic grain sizes

  5. ESRP approach to using final ecosystem services

    EPA Science Inventory

    The U.S. Environmental Protection Agency has developed the ecosystem Services Research Program (ESRP) as one of its major research efforts. The goal of this program is to create ?A comprehensive theory and practice for quantifying ecosystem services so that their value and their...

  6. Selenium Characterization in the Global Rice Supply Chain

    SciTech Connect

    Williams, Paul N.; Lombi, Enzo; Sun, Guo-Xin; Scheckel, Kirk; Zhu, Yong-Guan; Feng, Xinbin; Zhu, Jianming; Carey, Anne-Marie; Adomako, Eureka; Lawgali, Youseff; Deacon, Claire; Meharg, Andrew A.; (UCopenhagen); (Aberdeen); (Chinese Aca. Sci.); (US EPA)

    2009-08-13

    For up to 1 billion people worldwide, insufficient dietary intake of selenium (Se) is a serious health constraint. Cereals are the dominant Se source for those on low protein diets, as typified by the global malnourished population. With crop Se content constrained largely by underlying geology, regional soil Se variations are often mirrored by their locally grown staples. Despite this, the Se concentrations of much of the world's rice, the mainstay of so many, is poorly characterized, for both total Se content and Se speciation. In this study, 1092 samples of market sourced polished rice were obtained. The sampled rice encompassed dominant rice producing and exporting countries. Rice from the U.S. and India were found to be the most enriched, while mean average levels were lowest in Egyptian rice: {approx}32-fold less than their North American equivalents. By weighting country averages by contribution to either global production or export, modeled baseline values for both were produced. Based on a daily rice consumption of 300 g day{sup -1}, around 75% of the grains from the production and export pools would fail to provide 70% of daily recommended Se intakes. Furthermore, Se localization and speciation characterization using X-ray fluorescence ({mu}-XRF) and X-ray absorption near edge structure ({mu}-XANES) techniques were investigated in a Se-rich sample. The results revealed that the large majority of Se in the endosperm was present in organic forms.

  7. Rice University Rice Outdoor Programs and Education (ROPE) Internship

    E-print Network

    Rice University Rice Outdoor Programs and Education (ROPE) Internship Fall and Spring Semester 2012-2013 Position: Internship - Paid Location: Rice University, Houston, Texas Start Date: August 13th, 2012 End-lead students on outdoor adventure trips, aid in the teaching of a college course, and assist with supervision

  8. I Spy an Ecosystem

    NSDL National Science Digital Library

    Dr. Biology

    We hear the word ecosystems in the news and at school but just what are ecosystems? It turns out there are lots of ecosystems. You might even learn you have some inside you! Also in: Français | Español

  9. Viroplasm protein P9-1 of Rice black-streaked dwarf virus preferentially binds to single-stranded RNA in its octamer form, and the central interior structure formed by this octamer constitutes the major RNA binding site.

    PubMed

    Wu, Jianyan; Li, Jia; Mao, Xiang; Wang, Weiwu; Cheng, Zhaobang; Zhou, Yijun; Zhou, Xueping; Tao, Xiaorong

    2013-12-01

    The P9-1 protein of Rice black-streaked dwarf virus (RBSDV) is an essential part of the viroplasm. However, little is known about its nature or biological function in the viroplasm. In this study, the structure and function of P9-1 were analyzed for in vitro binding to nucleic acids. We found that the P9-1 protein preferentially bound to single-stranded versus double-stranded nucleic acids; however, the protein displayed no preference for RBSDV versus non-RBSDV single-stranded ssRNA (ssRNA). A gel mobility shift assay revealed that the RNA gradually shifted as increasing amounts of P9-1 were added, suggesting that multiple subunits of P9-1 bind to ssRNA. By using discontinuous blue native gel and chromatography analysis, we found that the P9-1 protein was capable of forming dimers, tetramers, and octamers. Strikingly, we demonstrated that P9-1 preferentially bound to ssRNA in the octamer, rather than the dimer, form. Deletion of the C-terminal arm resulted in P9-1 no longer forming octamers; consequently, the deletion mutant protein bound to ssRNA with significantly lower affinity and with fewer copies bound per ssRNA. Alanine substitution analysis revealed that electropositive amino acids among residues 25 to 44 are important for RNA binding and map to the central interior structure that was formed only by P9-1 octamers. Collectively, our findings provide novel insights into the structure and function of RBSDV viroplasm protein P9-1 binding to RNA. PMID:24067964

  10. Rheological properties of rice-blackgram batter while replacing white rice with brown rice.

    PubMed

    Manickavasagan, Annamalai; Al-Marhubi, Insaaf Mohd; Dev, Satyanarayan

    2014-06-01

    Rice-blackgram batter is a raw material for many traditional convenience foods in Asia. Reformulation of traditional convenience food by replacing white rice with whole rice (brown rice) is a novel method to reduce the consumption of refined grain and increase the intake of whole grain in our diet. In this study, rheological properties of rice-blackgram batter was investigated while replacing white rice with brown rice at five levels (T1--0% replacement (control), T2--25% replacement, T3--50% replacement, T4--75% replacement, and T5--100% replacement). The shear stress versus shear rate plot indicates that the rice-blackgram batter exhibited non-Newtonian fluid behavior (shear thinning property) even after 100% replacement of white rice with brown rice. The rheological characteristics of rice-blackgram batters fitted reasonably well in Cassan (r2 = 0.8521-0.9856) and power law (r2 = 0.8042-0.9823) models. Brown rice replacement at all levels did not affect the flow behavior index, yield stress, consistency coefficient, and apparent viscosity of batter at 25 degrees C. However, at higher temperature, the viscosity was greater for T4 and T5 (no difference between them) than T1, T2, and T3 (no difference between them) batters. Further research is required to determine the sensory attributes and acceptability of the cooked products with brown rice-blended batter. PMID:23751544

  11. Large scale germplasm screening for identification of novel rice blast resistance sources

    PubMed Central

    Vasudevan, Kumar; Vera Cruz, Casiana M.; Gruissem, Wilhelm; Bhullar, Navreet K.

    2014-01-01

    Rice is a major cereal crop that contributes significantly to global food security. Biotic stresses, including the rice blast fungus, cause severe yield losses that significantly impair rice production worldwide. The rapid genetic evolution of the fungus often overcomes the resistance conferred by major genes after a few years of intensive agricultural use. Therefore, resistance breeding requires continuous efforts of enriching the reservoir of resistance genes/alleles to effectively tackle the disease. Seed banks represent a rich stock of genetic diversity, however, they are still under-explored for identifying novel genes and/or their functional alleles. We conducted a large-scale screen for new rice blast resistance sources in 4246 geographically diverse rice accessions originating from 13 major rice-growing countries. The accessions were selected from a total collection of over 120,000 accessions based on their annotated rice blast resistance information in the International Rice Genebank. A two-step resistance screening protocol was used involving natural infection in a rice uniform blast nursery and subsequent artificial infections with five single rice blast isolates. The nursery-resistant accessions showed varied disease responses when infected with single isolates, suggesting the presence of diverse resistance genes/alleles in this accession collection. In addition, 289 accessions showed broad-spectrum resistance against all five single rice blast isolates. The selected resistant accessions were genotyped for the presence of the Pi2 resistance gene, thereby identifying potential accessions for isolation of allelic variants of this blast resistance gene. Together, the accession collection with broad spectrum and isolate specific blast resistance represent the core material for isolation of previously unknown blast resistance genes and/or their allelic variants that can be deployed in rice breeding programs. PMID:25324853

  12. Cucumber Tomato Rice Salad Ingredients

    E-print Network

    Liskiewicz, Maciej

    Cucumber Tomato Rice Salad Ingredients: 2 cups brown rice, cooked, or one cup uncooked rice 3 cucumbers, diced 1 tomato, seeded and diced 1 small onion, diced 2 teaspoons dill weed 1/2 cup low calorie bowl. 3. Wash tomato. Cut in half through the core. Use a paring knife to remove core. With flat side

  13. Huajian Gao James R. Rice

    E-print Network

    Huajian Gao James R. Rice Division of Applied Sciences, Harvard University, Cambridge, MA 02138 is based on the perturbation technique developed by Rice (1985) for solving the elastic field of a crack is suppressed and configurationally unstable if there is no such restraint. Introduction Rice (1985) developed

  14. Huajian Gao James R. Rice

    E-print Network

    Huajian Gao James R. Rice Division of Applied Sciences, Harvard University, Cambridge, Mass. 02138 Shear Stress Intensity Factors for a Planar Crack With Slightly Curved Front Recent work (Rice, 1985a be found. Rice (1985a) showed how the knowledge of such solutions enables one to calculate the changes

  15. Modeling moisture movement in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is one of the leading food crops in the world. At harvest, rice normally has higher moisture content than the moisture content considered safe for its storage, which creates the necessity for a drying process before its storage. In addition to drying, moisture movement within the rice kernels a...

  16. Degradation of chlorpyrifos in tropical rice soils.

    PubMed

    Das, Subhasis; Adhya, Tapan K

    2015-04-01

    Chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinol) phosphorothioate] is used worldwide as an agricultural insecticide against a broad spectrum of insect pests of economically important crops including rice, and soil application to control termites. The insecticide mostly undergoes hydrolysis to diethyl thiophosphoric acid (DETP) and 3,5,6-trichloro-2-pyridinol (TCP), and negligible amounts of other intermediate products. In a laboratory-cum-greenhouse study, chlorpyrifos, applied at a rate of 10 mg kg(-1) soil to five tropical rice soils of wide physico-chemical variability, degraded with a half-life ranging from 27.07 to 3.82 days. TCP was the major metabolite under both non-flooded and flooded conditions. Chlorpyrifos degradation had significant negative relationship with electrical conductivity (EC), cation exchange capacity (CEC), clay and sand contents of the soils under non-flooded conditions. Results indicate that degradation of chlorpyrifos was accelerated with increase in its application frequency, across the representative rice soils. Management regimes including moisture content and presence or absence of rice plants also influenced the process. Biotic factors also play an important role in the degradation of chlorpyrifos as demonstrated by its convincing degradation in mineral salts medium inoculated with non-sterile soil suspension. PMID:25617866

  17. Tagging and mapping of a rice gall midge resistance gene, Gm8 , and development of SCARs for use in marker-aided selection and gene pyramiding

    Microsoft Academic Search

    A. Jain; R. Ariyadasa; A. Kumar; M. N. Srivastava; M. Mohan; S. Nair

    2004-01-01

    Using amplified fragment length polymorphisms (AFLPs) and random amplified polymorphic DNAs (RAPDs), we have tagged and mapped Gm8, a gene conferring resistance to the rice gall midge ( Orseolia oryzae), a major insect pest of rice, onto rice chromosome 8. Using AFLPs, two fragments, AR257 and AS168, were identified that were linked to the resistant and susceptible phenotypes, respectively. Another

  18. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 47, NO. 2, FEBRUARY 2009 517 Monitoring of the Rice Cropping System in the

    E-print Network

    Boyer, Edmond

    of the Rice Cropping System in the Mekong Delta Using ENVISAT/ASAR Dual Polarization Data Alexandre Bouvet, Thuy Le Toan, and Nguyen Lam-Dao Abstract--The rice cropping system in Asia is undergoing major changes to cope with increasing demography and changing cli- mate, making rice monitoring a critical issue. Past

  19. Red rice control in rice using herbicides plus safeners

    E-print Network

    Price, James Bain

    1977-01-01

    of rice (O~r za sativa L. ) with NA (1, 8-napthalic anhydride) at 1% by seed weight significantly reduced the phytotoxicity of molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate) applied preplant incorporated to direct seeded rice. NA treatment... on the Activity of Molinate Against Red Rice when Applied at Various Times before Planting 15 17 18 20 21 CHAPTER I INTRODUCTION Red rice (~Or za sativa L. ) infests an estimated 400, 000 acres of rice land in the Southern United States. Heavy...

  20. Mammoth ecosystem: Climatic areal, animal's density and cause of extinctions

    Microsoft Academic Search

    S. Zimov; N. Zimov; G. Zimova; S. F. Chapin

    2008-01-01

    During the last glaciations Mammoth Ecosystem (ME) occupied territory from present-day France to Canada and from the Arctic islands to China. This ecosystem played major role in global carbon cycle and human settling around the planet. Causes of extinction of this ecosystem are debatable. Analyses of hundreds of radiocarbon dates of ME animal fossil remains showed that warming and moistening

  1. Climate Feedback on Methane Emissions From Terrestrial Ecosystems

    NASA Astrophysics Data System (ADS)

    Butenhoff, C. L.; Sithole, A.; Khalil, A. K.; Rice, A. L.; Shearer, M. J.

    2012-12-01

    Terrestrial ecosystems are one of the important components of the climate system that are bound to change and cause feedbacks with global warming. One major mechanism of this feedback is the response of biological processes, mostly bacteria, that produce or consume greenhouse gases such as carbon dioxide (CO2) and methane (CH4). Here we are concerned with the emissions of CH4 which is considered the most important non-CO2 greenhouse gas because it has more than doubled during the last century and is about 20 times more potent per kilogram once emitted to the atmosphere. Methane is produced by anaerobic methanogens in wetland soils and rice paddies, and is consumed by methanotrophic bacteria in aerobic and upland soils. Together these sources account for about 40-60% of global methane emissions. Properly accounting for the feedback of CH4 emissions with temperature in Earth Systems Models (ESMs) remains an open challenge in part due to the lack of experimental data. Reported Q10 values (factor by which reaction rate increases for a 10°C rise in temperature) of CH4 flux from wetlands and rice agriculture vary over an order of magnitude for reasons that are not well known contributing to this uncertainty. We report here a suite of experimental measurements to determine the Q10 of CH4 flux from rice agriculture and to understand how it depends on the temperature responses of its underlying processes. Since processes may have different Q10 values it is essential that these are properly represented in ESMs. We grew rice plants in temperature-controlled mesocosms at 20, 24, 28 and 32°C over two seasons (years 2009 - 2010) and measured flux, production and oxidation rates, at regular intervals using static chambers, soil core incubations, and carbon isotopes (?13C-CH4), respectively. In addition we used qPCR techniques to measure methyl coenzyme M reductase (mcrA) and particulate methane monooxygenase (pmoA) genes from mesocosm soil cores to establish the temperature response of methanogen and methanotroph populations. We used a simple box model to relate the flux Q10 with the Q10 values for production, oxidation, and plant-mediated transport. Among other results, we found that flux Q10 values varied between 1 and 20 on a day-to-day basis throughout the growing season, with the largest values occurring at the beginning of the season when fluxes were low. This variation could in part be explained by differences in rates of plant-mediated transport brought about by the different plant growth rates at different temperatures. The seasonally-averaged flux Q10 was ~2, which was lower than the average production Q10 of ~3, indicating that the temperature response of CH4 oxidation in part offsets the increased emissions expected from enhanced production at higher temperatures. This has important implications for how CH4 emissions from terrestrial ecosystems will respond to global warming.

  2. A Double Built-In Containment Strategy for Production of Recombinant Proteins in Transgenic Rice

    PubMed Central

    Zhao, Sinan; Shen, Zhicheng

    2014-01-01

    Using transgenic rice as a bioreactor for mass production of pharmaceutical proteins could potentially reduce the cost of production significantly. However, a major concern over the bioreactor transgenic rice is the risk of its unintended spreading into environment and into food or feed supplies. Here we report a mitigating method to prevent unwanted transgenic rice spreading by a double built-in containment strategy, which sets a selectively termination method and a visual tag technology in the T-DNA for transformation. We created transgenic rice with an inserted T-DNA that harbors a human proinsulin gene fused with the far-red fluorescent protein gene mKate_S158A, an RNAi cassette suppressing the expression of the rice bentazon detoxification enzyme CYP81A6, and an EPSPS gene as the selection marker for transformation. Herbicide spray tests indicated that such transgenic rice plants can be killed selectively by a spray of bentazon at regular field application dosage for rice weed control. Moreover, the transgenic rice seeds were bright red in color due to the fused far-red fluorescent protein, and could be easily visualized under daylight by naked eyes. Thus, the transgenic rice plants reported in this study could be selectively killed by a commonly used herbicide during their growth stage, and their seeds may be detected visually during processing and consumption after harvest. This double built-in containment strategy may greatly enhance the confinement of the transgenic rice. PMID:25531447

  3. Association mapping of starch physicochemical properties with starch biosynthesizing genes in waxy rice (Oryza sativa L.).

    PubMed

    Xu, Feifei; Zhang, Gan; Tong, Chuan; Sun, Xiao; Corke, Harold; Sun, Mei; Bao, Jinsong

    2013-10-23

    Waxy (glutinous) rice is widely used in traditional foods, and understanding the genetic bases of its diverse physicochemical properties will contribute to breeding of new waxy rice with unique qualities. The objective of this study was to investigate the genetic relationship between the starch biosynthesis related genes and the physicochemical properties of waxy rice using association mapping. A total of 36 molecular markers representing 18 genes were used to genotype 50 waxy rice accessions for which starch properties were previously available. Most of the starch properties differed between high and low gelatinization temperature (GT) groups, whereas most traits were similar between the low-GT indica rice and low-GT japonica rice, suggesting GT was the main determinant of the starch quality of waxy rice. Association mapping indicated that the starch properties of waxy rice were mainly controlled by starch synthase IIa (SSIIa or SSII-3, a major gene responsible for the gelatinization temperature) and SSI. It was found that gene-gene interactions were also important for the genetic control of starch properties of waxy rice. This study suggests that application of the functional SNPs of SSIIa in molecular breeding may facilitate quality improvement of waxy rice. PMID:24063600

  4. [Effects of phosphorus-containing substances on arsenic uptake by rice].

    PubMed

    Lei, Ming; Zeng, Min; Liao, Bo-Han; Hu, Li-Qiong; Zhou, Hang; Long, Shui-Bo

    2014-08-01

    The disodium hydrogen phosphate (DSP) and hydroxyapatite (HAP) were added into arsenic contaminated soil, then rice pot experiment was conducted to study the effects of phosphorus (P)-containing substances on arsenic (As) uptake by rice. The results showed that: DSP and HAP significantly increased soil pH and the contents of available P in soil (P < 0.05), activating soil arsenic. And DSP was stronger than HAP in improving the migration ability of As in soil. DSP and HAP treatments both significantly reduced the contents of total As in root, as well as total As and inorganic As in brown rice. But HAP significantly increased total As contents in stem. DSP and HAP treatments had better reducing effects on inorganic As than on total As in brown rice. And DSP had the same reducing effects as HAP on total As and inorganic As in brown rice. Analysis results showed that the contents of As in rice were affected by the antagonism between P and As and the increase of As bio-availability in soil. The antagonism played the major role in this study and it was clearly exhibited in both root and rice. Lower dosage (< or = 0.12 g x kg(-1)) of DSP and HAP increased total biomass of rice and brown rice yield, but with the increase of P addition, the two kinds of P-containing substances obviously inhibited the growth of rice, and inhibition by HAP was relatively light. PMID:25338392

  5. Transgenic Cry1Ab Rice Does Not Impact Ecological Fitness and Predation of a Generalist Spider

    PubMed Central

    Tian, Jun-Ce; Chen, Yang; Li, Zhao-Liang; Li, Kai; Chen, Mao; Peng, Yu-Fa; Hu, Cui; Shelton, Anthony M.; Ye, Gong-Yin

    2012-01-01

    Background The commercial release of rice genetically engineered to express a Cry1Ab protein from Bacillus thuringiensis (Bt) for control of Lepidoptera in China is a subject of debate. One major point of the debate has focused on the ecological safety of Bt rice on nontarget organisms, especially predators and parasitoids that help control populations of insect pests. Methodology/Principal Findings A tritrophic bioassay was conducted to evaluate the potential impact of Cry1Ab-expressing rice on fitness parameters of a predaceous ground spider (Pardosa pseudoannulata (Bösenberg et Strand)) that had fed on Bt rice-fed brown planthopper (Nilaparvata lugens (Stål)) nymphs. Survival, development time and fecundity of this spider were not different when they were fed with Bt rice-fed or non-Bt rice-fed prey. Furthermore, ELISA and PCR gut assays, as well as a functional response trial, indicated that predation by P. pseudoannulata was not significantly different in Bt rice or non-Bt rice fields. Conclusions/Significance The transgenic Cry1Ab rice lines tested in this study had no adverse effects on the survival, developmental time and fecundity of P. pseudoannulata in the laboratory or on predation under field conditions. This suggests that this important predator would not be harmed if transgenic Cry1Ab rice were commercialized. PMID:22511982

  6. Yield and Soil Nutrient Changes in a Long-Term Rice-Wheat Rotation in India

    Microsoft Academic Search

    A. L. Bhandari; J. K. Ladha; H. Pathak; A. T. Padre; D. Dawe; R. K. Gupta

    2002-01-01

    ganic nutrient sources on yield trends of rice and wheat, nutrient balances, and soil nutrient pools, and (ii) iden- Major improvements in the productivity of rice (Oryza sativa L.) tify reasons for the yield trends observed. and wheat (Triticum aestivum L.) have occurred in South Asia since 1965-1966 when the Green Revolution began. However, after the 1980s, yield stagnated or

  7. Methane and nitrous oxide emissions from subtropical rice agriculture in China

    Microsoft Academic Search

    M. A. K. Khalil; M. J. Shearer; R. A. Rasmussen; Li Xu; Jin-Luan Liu

    2008-01-01

    Emissions of methane and nitrous oxide, two significant greenhouse gases, were measured from rice fields at Qingyuan in Guangdong Province, China. The region has a subtropical climate which allows two crops of rice to be grown every year. The prevailing agricultural practices create a complex interaction between factors known to have a major effect on methane and nitrous oxide emissions

  8. Genetic Diversity for Concentration of Sixteen Mineral Elements Among Diverse Rice Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mineral nutrients such as Ca, Fe, and Zn play critical roles in human health, with over 3 billion people suffering from Fe and Zn deficiencies. Rice provides the major source of nutrition for a large proportion of the world’s population, but unfortunately, rice grain is not a good source of mineral...

  9. Field water management to save water and increase its productivity in irrigated lowland rice

    Microsoft Academic Search

    B. A. M. Bouman; T. P. Tuong

    2001-01-01

    Rice production in Asia needs to increase to feed a growing population whereas water for irrigation is getting scarcer. Major challenges are to (i) save water; (ii) increase water productivity and (iii) produce more rice with less water. This study analyzes the ways in which water-saving irrigation can help to meet these challenges at the field level. The analyses are

  10. Weed suppression potential of 'Rondo' and other indica rice germplasm lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high-yielding indica rice, 'Rondo' (4484-1693; PI 657830) which carries resistances to major rice diseases, was previously developed. We evaluated the weed suppression potential of Rondo, a sister line (4484-1665), and other indica lines against barnyardgrass in field plots in Stuttgart, AR, using...

  11. Seasonal assessment of greenhouse gas emission from irrigated lowland rice field under infrared warming

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice fields are considered as one of the major sources of methane (CH4), and they also emit nitrous oxide (N2O). A field experiment was conducted at the International Rice Research Institute, Philippines, in 2010 – 2011 using a temperature free-air controlled enhancement (T-FACE) system. Our object...

  12. Genetic variation and association mapping of protein concentration in rice using a germplasm collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice protein is an important source of nutrition and energy for a majority of the world’s population. However, the protein concentration in rice can have an impact on its flavor, texture, cooking and processing quality, thus, affecting its acceptability. It is therefore important to know if genet...

  13. Analysis of the effectiveness of the rice blast resistance gene Pi-ta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The casual agent of rice blast, Magnaporthe oryzae, continues to remain a serious threat for rice production and in general for the world food supply. The most economically and environmentally viable strategy to control this pathogen is the development of cultivars which possess major resistance gen...

  14. IDENTIFICATION OF NOVEL BLAST RESISTANCE GENES IN RICE CULTIVAR ZHE733

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blast disease caused by the fungus Magnaporthe grisea remains a serious threat to rice production in the U.S. Use of resistant cultivars is the most economic and efficient method to control blast disease. Rice has major genes conferring resistance to M. grisea races containing the corresponding av...

  15. A “Rice Diversity Panel” evaluated for genetic and agro-morphological variation between subpopulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since ancient times, Indica and Japonica have been recognized as the two major subspecies of Asian rice (Oryza sativa L.). First with isozymes and subsequently with DNA markers, five subpopulations indica, aus, temperate japonica, tropical japonica and aromatic/GroupV were identified. A “Rice Diver...

  16. Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates

    E-print Network

    Richards-Kortum, Rebecca

    194 Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from all disciplines build their leadership capacities to create and manage change effectively. Leadership to facilitate change. The introductory course, LEAD 309 Leadership: Theory to Practice (formerly UNIV 309

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

    PubMed

    Zhou, Guohui; Xu, Donglin; Xu, Dagao; Zhang, Maoxin

    2013-01-01

    Southern rice black-streaked dwarf virus (SRBSDV), a non-enveloped icosahedral virus with a genome of 10 double-stranded RNA segments, is a novel species in the genus Fijivirus (family Reoviridae) first recognized in 2008. Rice plants infected with this virus exhibit symptoms similar to those caused by Rice black-streaked dwarf virus. Since 2009, the virus has rapidly spread and caused serious rice losses in East and Southeast Asia. Significant progress has been made in recent years in understanding this disease, especially about the functions of the viral genes, rice-virus-insect interactions, and epidemiology and control measures. The virus can be efficiently transmitted by the white-backed planthopper (WBPH, Sogatella furcifera) in a persistent circulative propagative manner but cannot be transmitted by the brown planthopper (Nilaparvata lugens) and small brown planthopper (Laodelphax striatellus). Rice, maize, Chinese sorghum (Coix lacryma-jobi) and other grass weeds can be infected via WBPH. However, only rice plays a major role in the virus infection cycle because of the vector's preference. In Southeast Asia, WBPH is a long-distance migratory rice pest. The disease cycle can be described as follows: SRBSDV and its WBPH vector overwinter in warm tropical or sub-tropical areas; viruliferous WBPH adults carry the virus from south to north via long-distance migration in early spring, transmit the virus to rice seedlings in the newly colonized areas, and lay eggs on the infected seedlings; the next generation of WBPHs propagate on infected seedlings, become viruliferous, disperse, and cause new disease outbreaks. Several molecular and serological methods have been developed to detect SRBSDV in plant tissues and individual insects. Control measures based on protection from WBPH, including seedbed coverage, chemical seed treatments, and chemical spraying of seedlings, have proven effective in China. PMID:24058362

  18. Astronomical Ecosystems

    NASA Astrophysics Data System (ADS)

    Neuenschwander, D. E.; Finkenbinder, L. R.

    2004-05-01

    Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

  19. Enhanced conversion of plant biomass into glucose using transgenic rice-produced endoglucanase for cellulosic ethanol.

    PubMed

    Oraby, Hesham; Venkatesh, Balan; Dale, Bruce; Ahmad, Rashid; Ransom, Callista; Oehmke, James; Sticklen, Mariam

    2007-12-01

    The catalytic domain of Acidothermus cellulolyticus thermostable endoglucanase gene (encoding for endo-1,4-beta-glucanase enzyme or E1) was constitutively expressed in rice. Molecular analyses of T1 plants confirmed presence and expression of the transgene. The amount of E1 enzyme accounted for up to 4.9% of the plant total soluble proteins, and its accumulation had no apparent deleterious effects on plant growth and development. Approximately 22 and 30% of the cellulose of the Ammonia Fiber Explosion (AFEX)-pretreated rice and maize biomass respectively was converted into glucose using rice E1 heterologous enzyme. As rice is the major food crop of the world with minimal use for its straw, our results suggest a successful strategy for producing biologically active hydrolysis enzymes in rice to help generate alcohol fuel, by substituting the wasteful and polluting practice of rice straw burning with an environmentally friendly technology. PMID:17237981

  20. Novel insights into rice innate immunity against bacterial and fungal pathogens.

    PubMed

    Liu, Wende; Liu, Jinling; Triplett, Lindsay; Leach, Jan E; Wang, Guo-Liang

    2014-01-01

    Rice feeds more than half of the world's population. Rice blast, caused by the fungal pathogen Magnaporthe oryzae, and bacterial blight, caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae, are major constraints to rice production worldwide. Genome sequencing and extensive molecular analysis has led to the identification of many new pathogen-associated molecular patterns (PAMPs) and avirulence and virulence effectors in both pathogens, as well as effector targets and receptors in the rice host. Characterization of these effectors, host targets, and resistance genes has provided new insight into innate immunity in plants. Some of the new findings, such as the binding activity of X. oryzae transcriptional activator-like (TAL) effectors to specific rice genomic sequences, are being used for the development of effective disease control methods and genome modification tools. This review summarizes the recent progress toward understanding the recognition and signaling events that govern rice innate immunity. PMID:24906128

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Internet Geography: Ecosystems

    NSDL National Science Digital Library

    This site about ecosystems and biomes contains a map of different ecosystems, and provides rainfall statistics for each biome. There are sections on tropical rainforest, taiga (or boreal forest), savanna, desert, and tundra ecosystems. Each section describes the biome and its origins, where it is found, and how humans impact it. In some cases, sustainable development of the ecosystem is explained.

  3. Ecosystem element cycling Introduction

    E-print Network

    Ickert-Bond, Steffi

    Ecosystem element cycling Introduction An ecosystem consists of all the biological organisms and the physical environments they occupy together within a defined area [1]. The actual boundaries of an ecosystem are generally defined by researchers studying the ecosystem, who are usually interested in understanding

  4. Graduate studies Ecosystem Science

    E-print Network

    Graduate studies in Ecosystem Science and Management Ph.D. M.S. M.Agr. or Natural Resources Development MNRD Department of Ecosystem Science and Management College of Agriculture and Life Sciences in one or more of four broad research areas: ecosystem science; ecosystem management; spatial

  5. Biodiversity and ecosystem multifunctionality

    Microsoft Academic Search

    Andy Hector; Robert Bagchi

    2007-01-01

    Biodiversity loss can affect ecosystem functions and services. Individual ecosystem functions generally show a positive asymptotic relationship with increasing biodiversity, suggesting that some species are redundant. However, ecosystems are managed and conserved for multiple functions, which may require greater biodiversity. Here we present an analysis of published data from grassland biodiversity experiments, and show that ecosystem multifunctionality does require greater

  6. USA RICE FEDERATION PERSPECTIVES ON THE IMPACTS OF BLACKBIRDS ON THE RICE INDUSTRY

    Microsoft Academic Search

    The USA Rice Federation comprises all segments of the United States rice industry. The federation was formed by 3 charter members: the U.S. Rice Producers' Group, the Rice Millers' Association and the USA Rice Council. Today's rice industry faces serious challenges on every front - lack of an adequate economic safety net for producers, increased regulatory controls, trade barriers, and

  7. Gene expression related to seed shattering and the cell wall in cultivated and weedy rice.

    PubMed

    Nunes, A L; Delatorre, C A; Merotto, A

    2014-09-01

    Seed shattering is an evolutionary trait that is essential to the survival of wild and weedy rice. Discovery of the qSH1 gene in rice subspecies Japonica and Sh4 in the rice subspecies Indica indicated the possibility that seed shattering is governed by major genes in a qualitative manner. However, observation of the large variability of seed shattering in weedy rice has led us to hypothesise that other genes related to abscission layer integrity could also be important in the regulation of seed shattering in rice. Gene expression 10 days after pollination and nucleotide composition revealed that qSH1 and Sh4 that are described as major players in seed shattering were not important in weedy rice. High expression of the gene OsCPL1 was positively associated with the occurrence of high seed shattering in weedy rice, which did not concur in previous studies of cultivated rice. This result is related to the absence of four SNPs and an indel in the OsCPL1 gene in weedy rice that are related to seed shattering in previous studies. Analysis of the expression of six genes related to cell wall synthesis/degradation revealed the importance of the genes OsXTH8 and OsCel9D in seed shattering in weedy rice. Therefore, in addition to qSH1 and Sh4, the genes OsCPL1, OsXTH8 and OsCel9D should be considered in studies of rice evolution and in the development of mitigation approaches of gene flow in transgenic rice. PMID:24597823

  8. Rice disease management under organic production

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Phenol accumulation in a young humic fraction following anaerobic decomposition of rice crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil phenols have been implicated as inhibitors of soil nitrogen (N) cycling within many ecosystems, including irrigated lowland rice (Orzyza sativa, L.) in the Philippines. We measured soil phenol concentrations in two humic fractions at two crop growth stages in each season during a 4-year field s...

  10. Evaluation of potential effects of soil available phosphorus on soil arsenic availability and paddy rice inorganic arsenic content.

    PubMed

    Jiang, Wei; Hou, Qingye; Yang, Zhongfang; Zhong, Cong; Zheng, Guodong; Yang, Zhiqiang; Li, Jie

    2014-05-01

    The transfer of arsenic from paddy field to rice is a major exposure route of the highly toxic element to humans. The aim of our study is to explore the effects of soil available phosphorus on As uptake by rice, and identify the effects of soil properties on arsenic transfer from soil to rice under actual field conditions. 56 pairs of topsoil and rice samples were collected. The relevant parameters in soil and the inorganic arsenic in rice grains were analyzed, and then all the results were treated by statistical methods. Results show that the main factors influencing the uptake by rice grain include soil pH and available phosphorus. The eventual impact of phosphorus is identified as the suppression of As uptake by rice grains. The competition for transporters from soil to roots between arsenic and phosphorus in rhizosphere soil has been a dominant feature. PMID:24598788

  11. Arsenic uptake and speciation in rice plants grown under greenhouse conditions with arsenic contaminated irrigation water.

    PubMed

    Smith, E; Juhasz, A L; Weber, J; Naidu, R

    2008-03-25

    The accumulation of arsenic (As) by rice (Oryza sativa L.) is of great interest considering the dietary intake of rice is potentially a major As exposure pathway in countries where rice is irrigated with As contaminated groundwater. A small scale rice paddy experiment was conducted to evaluate the uptake of As by rice. Arsenic concentrations in rice tissue increased in the order grainrice grain, in some cases, exceeding the maximum Australian permissible concentration of 1 mg kg(-1). Speciation of As in rice tissue was performed using a modified protein extraction procedure and trifluoroacetic acid extraction. Whilst higher As recoveries were obtained using trifluoroacetic acid extraction, both methods identified arsenite and arsenate as the major As species present in the root, stem and leaf, however, arsenite and dimethylarsinic acid (DMA) were the major As species identified in the grain. Notably, DMA comprised 85 to 94% of the total As concentration in the grain. The high proportion of organic to inorganic As in the grain has implications on human health risk assessment as inorganic As species are more bioavailable than methylated As species. PMID:18164371

  12. Flooded Wild Rice River

    USGS Multimedia Gallery

    Wild Rice River at Great Bend North Dakota, streamflow 1,890 cubic feet per second.  Photograph taken during spring 2010 flooding looking downstream of the bridge which was clogged with debris.  The river also had flooded over the road approaching the bridge....

  13. Rice: chemistry and technology.

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. RICE MICROSTRUCTURE - COMPARING CULTIVARS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microstructures of short, medium, long and waxy grain rices were compared for microstructural characteristics using scanning electron and light microscopies. The cultivars in this study included three short grain (Akitakamachi, Koshihikari and S102); three medium grain (Bengal, M202 and M401); f...

  15. Rice bran phytonutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bran layer of the whole grain rice contains potential health-beneficial compounds. These include vitamin E homologs (tocopherols, tocotrienols), oryzanol fractions, simple phenolics and poly-phenolics. These are antioxidants that are believed to provide protection against diseases such as cancer...

  16. Enzyme dynamics in paddy soils of the rice district (NE Italy) under different cropping patterns

    NASA Astrophysics Data System (ADS)

    Bini, Claudio; Nadimi-Goki, Mandana; Kato, Yoichi; Fornasier, Flavio; Wahsha, Mohammad; Spiandorello, Massimo

    2014-05-01

    The recent widespread interest on soil enzymes is due to the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land managers in promoting long-term sustainability of terrestrial ecosystems. The activities of six important enzymes involved in C, N, P, and S cycling were investigated in a paddy soil from the Veneto region, Italy, in four different rotation systems (rice-rice-rice: R-R-R; soya-rice-rice: S-R-R; fallow-rice: F-R; pea-soya-rice: P-S-R) with three replications in April (after field preparation, field moist condition), June (after seedling, waterlogged soil condition), August (after tillering stage of rice, waterlogged soil condition) and October (after rice harvesting, drained soil condition) over the 2012 growing season. Our results demonstrated that enzyme activities varied with rotation systems and growth stages in paddy soil. Compared with field moist soil, drained soil condition resulted in a significant increase (P < 0.05) of ?-glucosidase, arylsulfatase, alkaline and acid phosphatases, leucine aminopeptidase (except of fallow-rice), and chitinase activities in all rotations, while compared with drained soil, early waterlogging (in month of June) significantly decreased (P moist soil> late waterlogged>early waterlogged. There was an inhibitory effect of waterlogging (except P-S-R rotation) for both alkaline and acid phosphatases due to high pH and redox conditions. However, the response of enzymes to waterlogging differed with the chemical species and the cropping pattern. The best rotation system for chitinase, leucine aminopeptidase and ?-glucosidase activity (C and N cycles) proved R-R-R, while for arylsulfatase, alkaline and acid phosphatases (P and S cycles) it was the S-R-R. Key Words: enzyme activity, paddy soil, Crop Rotation System, Italy __ Corresponding Author: Mandana Nadimi-Goki, Tel.: +39 3891356251 E-mail address: mandy.nadimi@gmail.com

  17. SNP in starch biosynthesis genes associated with nutritional and functional properties of rice

    PubMed Central

    Kharabian-Masouleh, Ardashir; Waters, Daniel L. E.; Reinke, Russell F.; Ward, Rachelle; Henry, Robert J.

    2012-01-01

    Starch is a major component of human diets. The relative contribution of variation in the genes of starch biosynthesis to the nutritional and functional properties of the rice was evaluated in a rice breeding population. Sequencing 18 genes involved in starch synthesis in a population of 233 rice breeding lines discovered 66 functional SNPs in exonic regions. Five genes, AGPS2b, Isoamylase1, SPHOL, SSIIb and SSIVb showed no polymorphism. Association analysis found 31 of the SNP were associated with differences in pasting and cooking quality properties of the rice lines. Two genes appear to be the major loci controlling traits under human selection in rice, GBSSI (waxy gene) and SSIIa. GBSSI influenced amylose content and retrogradation. Other genes contributing to retrogradation were GPT1, SSI, BEI and SSIIIa. SSIIa explained much of the variation in cooking characteristics. Other genes had relatively small effects. PMID:22870386

  18. Ecosystem health: I. Measuring ecosystem health

    NASA Astrophysics Data System (ADS)

    Schaeffer, David J.; Herricks, Edwin E.; Kerster, Harold W.

    1988-07-01

    Ecosystem analysis has been advanced by an improved understanding of how ecosystems are structured and how they function. Ecology has advanced from an emphasis on natural history to consideration of energetics, the relationships and connections between species, hierarchies, and systems theory. Still, we consider ecosystems as entities with a distinctive character and individual characteristics. Ecosystem maintenance and preservation form the objective of impact analysis, hazard evaluation, and other management or regulation activities. In this article we explore an approach to ecosystem analysis which identifies and quantifies factors which define the condition or state of an ecosystem in terms of health criteria. We relate ecosystem health to human/nonhuman animal health and explore the difficulties of defining ecosystem health and suggest criteria which provide a functional definition of state and condition. We suggest that, as has been found in human/nonhuman animal health studies, disease states can be recognized before disease is of clinical magnitude. Example disease states for ecosystems are functionally defined and discussed, together with test systems for their early detection.

  19. Coral Reef Ecosystems: Ecosystems in Crisis

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2007-03-28

    This Science Object is the fourth of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the natural and human causes of ecosystem stress. Human beings live near coral ecosystems and use them in a variety of ways. Increasing amounts of stress is brought on these ecosystems as humans continue to modify the surrounding environment as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening the stability and overall health of many coral reefs. Human activities may also exacerbate the impact of natural disturbances on coral reefs or compromise the ability of the reef to recover from events such as hurricanes, tsunamis, or disease. Learning Outcomes:? Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).? Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).? Explain how human activity may decrease the reefs ability to recover from natural occurrences. ? Explain the effects of increased predation or disease on a reef ecosystem.? Describe the effect of habitat loss on the reef ecosystem.? Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

  20. Genetic Differentiation Revealed by Selective Loci of Drought-Responding EST-SSRs between Upland and Lowland Rice in China

    PubMed Central

    Xia, Hui; Zheng, Xiaoguo; Chen, Liang; Gao, Huan; Yang, Hua; Long, Ping; Rong, Jun; Lu, Baorong; Li, Jiajia; Luo, Lijun

    2014-01-01

    Upland and lowland rice (Oryza sativa L.) represent two of the most important rice ecotypes adapted to ago-ecosystems with contrasting soil-water conditions. Upland rice, domesticated in the water-limited environment, contains valuable drought-resistant characters that can be used in water-saving breeding. Knowledge about the divergence between upland and lowland rice will provide valuable cues for the evolution of drought-resistance in rice. Genetic differentiation between upland and lowland rice was explored by 47 Simple Sequence Repeats (SSRs) located in drought responding expressed sequence tags (ESTs) among 377 rice landraces. The morphological traits of drought-resistance were evaluated in the field experiments. Different outlier loci were detected in the japonica and indica subspecies, respectively. Considerable genetic differentiation between upland and lowland rice on these outlier loci was estimated in japonica (Fst?=?0.258) and indica (Fst?=?0.127). Furthermore, populations of the upland and lowland ecotypes were clustered separately on these outlier loci. A significant correlation between genetic distance matrices and the dissimilarity matrices of drought-resistant traits was determined, indicating a certain relationship between the upland-lowland rice differentiation and the drought-resistance. Divergent selections occur between upland and lowland rice on the drought-resistance as the Qsts of some drought-resistant traits are significantly higher than the neutral Fst. In addition, the upland- and lowland-preferable alleles responded differently among ecotypes or allelic types under osmotic stress. This shows the evolutionary signature of drought resistance at the gene expression level. The findings of this study can strengthen our understanding of the evolution of drought-resistance in rice with significant implications in the improvement of rice drought-resistance. PMID:25286109

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

    PubMed Central

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

    2014-01-01

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

  2. Texas Rice, Volume IV, Number 2

    E-print Network

    in 2003 that had not previously been identified in Texas rice fields. While the reports were mostly localized, farmers are encouraged to keep a vigilant watch throughout the rice belt. The new- comers include three species of aphids, rice whorl maggot... continued... continued on next page Yellow sugarcane aphids also feed on rice and sorghum. Photo courtesy of Greg Cronholm, Texas A&M University. Photo courtesy of K.E. Mueller, International Rice Research Institute. Rice whorl maggots are difficult...

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Wetlands often are associated with elevated methylmercury (MeHg) production and food web bioaccumulation, making them potentially important sources of Hg to surrounding waters and to wetland-dependent fish and wildlife. However, the cycling of MeHg through wetlands can vary markedly with wetland type. Agricultural wetlands such as rice fields can exhibit particularly pronounced MeHg concentrations and bioaccumulation because their biogeochemical, hydrological, and ecological characteristics facilitate the conversion of inorganic mercury (Hg) to MeHg. Rice fields are characterized by a series of seasonal extreme wetting and drying cycles, sulfate-containing fertilizers, and high levels of labile organic carbon, all of which are key processes in the Hg cycle. Rice fields comprise approximately 20% of freshwater habitats and 11% of cultivated land area globally, providing critical wildlife habitat while offering substantial economic, human health, and ecosystem benefits. Thus, there is strong impetus to better understand the drivers of Hg cycling in rice fields and to develop useful management approaches for minimizing Hg risk associated with rice agriculture without compromising rice production. We examined the role of rice wetlands on MeHg bioaccumulation through foodwebs by employing biosentinel caged fish as integrators of MeHg cycling processes. With experimental field studies in California's Central Valley, we placed biosentinel fishes into nine rice wetlands that were subjected to three different harvest strategies, and into nine managed wetlands that encompassed three different hydrological regimes. We simultaneously measured a suite of biogeochemical processes in surface water, sediment, and pore water in order to link the response in fish Hg bioaccumulation with within-field processes that regulate MeHg cycling. Our preliminary results indicate that fish Hg concentrations were 1.6 times higher in rice wetlands than in managed wetlands. Additionally, fish Hg concentrations increased across rice fields from inlets to outlets indicating that in situ processes enhanced MeHg production rice fields, whereas concentrations decreased from inlets to outlets in managed wetlands. Finally, our preliminary results suggest organic carbon associated with rice plants was an important contributor to fish Hg concentrations, whereas plants in managed wetlands were not strongly linked to fish Hg concentrations. Our preliminary findings suggest that there are strong linkages between biogeochemical processes inherent in rice wetlands and MeHg cycling and bioaccumulation, which are further described in a companion presentation by Windham-Myers (this session). These results have important implications for managing MeHg risk in areas with extensive rice agriculture.

  4. A brief review of approaches using ciliated protists to assess aquatic ecosystem health

    Microsoft Academic Search

    Denis H. Lynn; Guy L. Gilron

    1992-01-01

    Ciliated protists are important components of marine and freshwater ecosystems. As such, their usefulness as indicators of aquatic ecosystem health has been recognized. Two major technical approaches have been employed: (1) community assessment, and (2) toxicological tests. Community assessment of an aquatic ecosystem must at least include comparisons to either baseline data on the ecosystem under study or to ‘pristine’

  5. Study of chemical pretreatment and enzymatic saccharification for producing fermentable sugars from rice straw.

    PubMed

    Chen, Wen-Hsing; Chen, Yi-Chun; Lin, Jih-Gaw

    2014-07-01

    This study evaluated a cost-effective approach for the conversion of rice straw into fermentable sugars. The composition of rice straw pretreated with 1 % sulfuric acid or 1 % sodium hydroxide solution was compared to rice straw with no chemical pretreatment. Enzymatic saccharification experiments on non-pretreated rice straw (NPRS), pretreated rice straw (PRS), and pretreated rice straw with acid hydrolysate (PRSAH) were conducted in a series of batch reactors. The results indicated that pretreating the rice straw with dilute acid and base increased the cellulose content from 38 % to over 50 %. During enzymatic saccharification, straight aliphatic cellulose was hydrolyzed before branched hemicellulose, and glucose was the major hydrolysis product. The glucose yield was 0.52 g glucose/g for NPRS and was comparable to the yields of 0.50 g glucose/g for PRS and 0.58 g glucose/g for PRSAH. The hydrolysis of rice straw to produce glucose can be described by a first-order reaction with a rate constant of 0.0550 d(-1) for NPRS, 0.0653 d(-1) for PRSAH, and 0.0654 d(-1) for PRS. Overall, the production of fermentable sugars from ground rice straw will be more cost effective if the straw is not pretreated with chemicals. PMID:24346765

  6. Improved yield and Zn accumulation for rice grain by Zn fertilization and optimized water management.

    PubMed

    Wang, Yu-yan; Wei, Yan-yan; Dong, Lan-xue; Lu, Ling-li; Feng, Ying; Zhang, Jie; Pan, Feng-shan; Yang, Xiao-e

    2014-04-01

    Zinc (Zn) deficiency and water scarcity are major challenges in rice (Oryza sativa L.) under an intensive rice production system. This study aims to investigate the impact of water-saving management and different Zn fertilization source (ZnSO4 and Zn-EDTA) regimes on grain yield and Zn accumulation in rice grain. Different water managements, continuous flooding (CF), and alternate wetting and drying (AWD) were applied during the rice growing season. Compared with CF, the AWD regime significantly increased grain yield and Zn concentrations in both brown rice and polished rice. Grain yield of genotypes (Nipponbare and Jiaxing27), on the average, was increased by 11.4%, and grain Zn concentration by 3.9% when compared with those under a CF regime. Zn fertilization significantly increased Zn density in polished rice, with a more pronounced effect of ZnSO4 being observed as compared with Zn-EDTA, especially under an AWD regime. Decreased phytic acid content and molar ratio of phytic acid to Zn were also noted in rice grains with Zn fertilization. The above results demonstrated that water management of AWD combined with ZnSO4 fertilization was an effective agricultural practice to elevate grain yield and increase Zn accumulation and bioavailability in rice grains. PMID:24711357

  7. Rice proteomics: a model system for crop improvement and food security.

    PubMed

    Kim, Sun Tae; Kim, Sang Gon; Agrawal, Ganesh Kumar; Kikuchi, Shoshi; Rakwal, Randeep

    2014-03-01

    Rice proteomics has progressed at a tremendous pace since the year 2000, and that has resulted in establishing and understanding the proteomes of tissues, organs, and organelles under both normal and abnormal (adverse) environmental conditions. Established proteomes have also helped in re-annotating the rice genome and revealing the new role of previously known proteins. The progress of rice proteomics had recognized it as the corner/stepping stone for at least cereal crops. Rice proteomics remains a model system for crops as per its exemplary proteomics research. Proteomics-based discoveries in rice are likely to be translated in improving crop plants and vice versa against ever-changing environmental factors. This review comprehensively covers rice proteomics studies from August 2010 to July 2013, with major focus on rice responses to diverse abiotic (drought, salt, oxidative, temperature, nutrient, hormone, metal ions, UV radiation, and ozone) as well as various biotic stresses, especially rice-pathogen interactions. The differentially regulated proteins in response to various abiotic stresses in different tissues have also been summarized, indicating key metabolic and regulatory pathways. We envision a significant role of rice proteomics in addressing the global ground level problem of food security, to meet the demands of the human population which is expected to reach six to nine billion by 2040. PMID:24323464

  8. Multiscale Experimental Ecosystem Research Center (MEERC)

    NSDL National Science Digital Library

    Based at the University of Maryland's Center for Environmental Science, the mission of MEERC (Multiscale Experimental Ecosystem Research Center) is "to contribute to the fundamental understanding of the scale-dependent behavior of experimental and natural estuarine ecosystems, so that research information can be extrapolated systematically among experimental ecosystems and nature, and among natural ecosystems of different dimensions." Five major research projects are described at the homepage for the period 1998-2000, including Scaling Trophic Interactions in Pelagic Estuarine Ecosystems and Ecotoxicology and Issues of Scale, among others. The site also includes recent research highlights, a hyperlinked list of participating research labs, an impressive list of recent scientific publications and reports, and a selection of related links.

  9. Soil nitric oxide emissions from terrestrial ecosystems in China: a synthesis of modeling and measurements

    PubMed Central

    Huang, Yong; Li, Dejun

    2014-01-01

    Soils are among the major sources of atmospheric nitric oxide (NO), which play a crucial role in atmospheric chemistry. Here we systematically synthesized the modeling studies and field measurements and presented a novel soil NO emission inventory of terrestrial ecosystems in China. The previously modeled inventories ranged from 480 to 1375 and from 242.8 to 550?Gg N yr?1 for all lands and croplands, respectively. Nevertheless, all the previous modeling studies were conducted based on very few measurements from China. According to the current synthesis of field measurements, most soil NO emission measurements were conducted at croplands, while the measurements were only conducted at two sites for forest and grassland. The median NO flux was 3.2?ng N m?2 s?1 with a fertilizer induced emission factor (FIE) of 0.04% for rice fields, and was 7.1?ng N m?2 s?1 with an FIE of 0.67% for uplands. A novel NO emission inventory of 1226.33 (ranging from 588.24 to 2132.05) Gg N yr?1 was estimated for China's terrestrial ecosystems, which was about 18% of anthropogenic emissions. More field measurements should be conducted to cover more biomes and obtain more representative data in order to well constrain soil NO emission inventory of China. PMID:25490942

  10. Soil nitric oxide emissions from terrestrial ecosystems in China: a synthesis of modeling and measurements

    NASA Astrophysics Data System (ADS)

    Huang, Yong; Li, Dejun

    2014-12-01

    Soils are among the major sources of atmospheric nitric oxide (NO), which play a crucial role in atmospheric chemistry. Here we systematically synthesized the modeling studies and field measurements and presented a novel soil NO emission inventory of terrestrial ecosystems in China. The previously modeled inventories ranged from 480 to 1375 and from 242.8 to 550 Gg N yr-1 for all lands and croplands, respectively. Nevertheless, all the previous modeling studies were conducted based on very few measurements from China. According to the current synthesis of field measurements, most soil NO emission measurements were conducted at croplands, while the measurements were only conducted at two sites for forest and grassland. The median NO flux was 3.2 ng N m-2 s-1 with a fertilizer induced emission factor (FIE) of 0.04% for rice fields, and was 7.1 ng N m-2 s-1 with an FIE of 0.67% for uplands. A novel NO emission inventory of 1226.33 (ranging from 588.24 to 2132.05) Gg N yr-1 was estimated for China's terrestrial ecosystems, which was about 18% of anthropogenic emissions. More field measurements should be conducted to cover more biomes and obtain more representative data in order to well constrain soil NO emission inventory of China.

  11. The Native Cyclobutane Pyrimidine Dimer Photolyase of Rice Is Phosphorylated1[C][OA

    PubMed Central

    Teranishi, Mika; Nakamura, Kentaro; Morioka, Hiroshi; Yamamoto, Kazuo; Hidema, Jun

    2008-01-01

    The cyclobutane pyrimidine dimer (CPD) is a major type of DNA damage induced by ultraviolet B (UVB) radiation. CPD photolyase, which absorbs blue/UVA light as an energy source to monomerize dimers, is a crucial factor for determining the sensitivity of rice (Oryza sativa) to UVB radiation. Here, we purified native class II CPD photolyase from rice leaves. As the final purification step, CPD photolyase was bound to CPD-containing DNA conjugated to magnetic beads and then released by blue-light irradiation. The final purified fraction contained 54- and 56-kD proteins, whereas rice CPD photolyase expressed from Escherichia coli was a single 55-kD protein. Western-blot analysis using anti-rice CPD photolyase antiserum suggested that both the 54- and 56-kD proteins were the CPD photolyase. Treatment with protein phosphatase revealed that the 56-kD native rice CPD photolyase was phosphorylated, whereas the E. coli-expressed rice CPD photolyase was not. The purified native rice CPD photolyase also had significantly higher CPD photorepair activity than the E. coli-expressed CPD photolyase. According to the absorption, emission, and excitation spectra, the purified native rice CPD photolyase possesses both a pterin-like chromophore and an FAD chromophore. The binding activity of the native rice CPD photolyase to thymine dimers was higher than that of the E. coli-expressed CPD photolyase. These results suggest that the structure of the native rice CPD photolyase differs significantly from that of the E. coli-expressed rice CPD photolyase, and the structural modification of the native CPD photolyase leads to higher activity in rice. PMID:18235036

  12. Neglecting Rice Milling Yield and Quality Underestimates Economic Losses from High-Temperature Stress

    PubMed Central

    Lyman, Nathaniel B.; Jagadish, Krishna S. V.; Nalley, L. Lanier; Dixon, Bruce L.; Siebenmorgen, Terry

    2013-01-01

    Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of high-temperature stress on rice production have focused on paddy yield and have failed to account for the detrimental impact of high temperatures on milling quality outcomes, which ultimately determine edible (marketable) rice yield and market value. Using genotype specific rice yield and milling quality data on six common rice varieties from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, we show a nonlinear effect of high-temperature stress exposure on yield and milling quality. A 1°C increase in average growing season temperature reduces paddy yield by 6.2%, total milled rice yield by 7.1% to 8.0%, head rice yield by 9.0% to 13.8%, and total milling revenue by 8.1% to 11.0%, across genotypes. Our results indicate that failure to account for changes in milling quality leads to understatement of the impacts of high temperatures on rice production outcomes. These dramatic losses result from reduced paddy yield and increased percentages of chalky and broken kernels, which together decrease the quantity and market value of milled rice. Recently published estimates show paddy yield reductions of up to 10% across the major rice-producing regions of South and Southeast Asia due to rising temperatures. The results of our study suggest that the often-cited 10% figure underestimates the economic implications of climate change for rice producers, thus potentially threatening future food security for global rice producers and consumers. PMID:23991056

  13. Water management affects arsenic and cadmium accumulation in different rice cultivars.

    PubMed

    Hu, Pengjie; Huang, Jiexue; Ouyang, Younan; Wu, Longhua; Song, Jing; Wang, Songfeng; Li, Zhu; Han, Cunliang; Zhou, Liqiang; Huang, Yujuan; Luo, Yongming; Christie, Peter

    2013-12-01

    Paddy rice (Oryza sativa L.) is a staple food and one of the major sources of dietary arsenic (As) and cadmium (Cd) in Asia. A field experiment was conducted to investigate the effects of four water management regimes (aerobic, intermittent irrigation, conventional irrigation and flooding) on As and Cd accumulation in seven major rice cultivars grown in Zhejiang province, east China. With increasing irrigation from aerobic to flooded conditions, the soil HCl-extractable As concentrations increased significantly and the HCl-extractable Cd concentrations decreased significantly. These trends were consistent with the As and Cd concentrations in the straw, husk and brown rice. Water management both before and after the full tillering stage affected As and Cd accumulation in the grains. The intermittent and conventional treatments produced higher grain yields than the aerobic and flooded treatments. Cd concentrations in brown rice varied 13.1-40.8 times and As varied 1.75-8.80 times among the four water management regimes. Cd and As accumulation in brown rice varied among the rice cultivars, with Guodao 6 (GD6) was a low Cd but high-As-accumulating cultivar while Indonesia (IR) and Yongyou 9 (YY9) were low As but high-Cd-accumulating cultivars. Brown rice Cd and As concentrations in the 7 cultivars were significantly negatively correlated. The results indicate that As and Cd accumulated in rice grains with opposite trends that were influenced by both water management and rice cultivar. Production of 'safe' rice with respect to As and Cd might be possible by balancing water management and rice cultivar according to the severity of soil pollution. PMID:23719663

  14. Weed management in dry-seeded rice ( Oryza sativa) cultivated in the furrow-irrigated raised-bed planting system

    Microsoft Academic Search

    Samar Singh; Lav Bhushan; J. K. Ladha; R. K. Gupta; A. N. Rao; B. Sivaprasad

    2006-01-01

    Dry seeding of rice (Oryza sativa L.) in the furrow-irrigated raised-bed planting system (FIRBS) represents a major shift in the production practices for attaining optimal water productivity in the rice–wheat system in the Indo-Gangetic Plains of South Asia. Information on weed management in dry-seeded rice in the FIRBS is lacking. Two experiments were conducted for 2 years, with an objective

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

    PubMed Central

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

    2012-01-01

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

  16. Arsenic accumulation and speciation in rice grains influenced by arsenic phytotoxicity and rice genotypes grown in arsenic-elevated paddy soils.

    PubMed

    Syu, Chien-Hui; Huang, Chia-Chen; Jiang, Pei-Yu; Lee, Chia-Hsing; Lee, Dar-Yuan

    2015-04-01

    Rice consumption is a major route of As exposure to human for the population of worldwide. This study investigates the effect of phytotoxicity and rice genotypes on the content and speciation of As in rice grains grown in different levels of As-elevated paddy soils from Taiwan. Three levels of As-elevated soils and six rice genotypes commonly planted in Taiwan were used for this study. The results indicate that As contents in grains of rice is not proportional to soil As concentrations and they were equal or higher in indica genotypes than japonica genotypes used in this study. It was also found that the As phytotoxicity not only reducing the grain yields but also the As concentrations in grain of rice. The predominant As species found in rice grains were dimethylarsinic acid (DMA) and arsenite. The concentrations of DMA increased with total As concentrations, wherggeas the arsenite remained in a narrow range from 0.1 to 0.3mgkg(-1). Because of the lower toxicity of DMA than inorganic As species, the health risks may not be increased through consumption of rice even when total As content in the grains is increased. PMID:25577320

  17. Consideration of Ecosystem for ICME

    SciTech Connect

    Ren, Weiju [ORNL

    2013-01-01

    As the Integrated Computational Materials Engineering (ICME) emerges as a hot topic, computation, experimentation, and digital database are identified as its three major components. Efforts are being actively made from various aspects to bring ICME to reality. However, many factors that would affect ICEM development still remain vague. This paper is an attempt to discuss the needs for establishing a database centered ecosystem to facilitate ICEM development.

  18. Biogeochemical Processes in Microbial Ecosystems

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.

    2001-01-01

    The hierarchical organization of microbial ecosystems determines process rates that shape Earth's environment, create the biomarker sedimentary and atmospheric signatures of life, and define the stage upon which major evolutionary events occurred. In order to understand how microorganisms have shaped the global environment of Earth and, potentially, other worlds, we must develop an experimental paradigm that links biogeochemical processes with ever-changing temporal and spatial distributions of microbial populations and their metabolic properties. Additional information is contained in the original extended abstract.

  19. Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?

    E-print Network

    Berkowitz, Alan R.

    COMMENTARY Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation? Gary M. Lovett ABSTRACT Net ecosystem production (NEP), defined as the difference between gross primary production: net ecosystem production; carbon accumulation; net primary production; gross pri- mary production

  20. Diversity of Cultivable Methane-Oxidizing Bacteria in Microsites of a Rice Paddy Field: Investigation by Cultivation Method and Fluorescence in situ Hybridization (FISH)

    PubMed Central

    Dianou, Dayéri; Ueno, Chihoko; Ogiso, Takuya; Kimura, Makoto; Asakawa, Susumu

    2012-01-01

    The diversity of cultivable methane-oxidizing bacteria (MOB) in the rice paddy field ecosystem was investigated by combined culture-dependent and fluorescence in situ hybridization (FISH) techniques. Seven microsites of a Japanese rice paddy field were the focus of the study: floodwater, surface soil, bulk soil, rhizosphere soil, root, basal stem of rice plant, and rice stumps of previous harvest. Based on pmoA gene analysis and transmission electron microscopy (TEM), four type I, and nine type II MOB isolates were obtained from the highest dilution series of enrichment cultures. The type I MOB isolates included a novel species in the genus Methylomonas from floodwater and this is the first type I MOB strain isolated from floodwater of a rice paddy field. In the type I MOB, two isolates from stumps were closely related to Methylomonas spp.; one isolate obtained from rhizosphere soil was most related to Methyloccocus-Methylocaldum-Methylogaea clade. Almost all the type II MOB isolates were related to Methylocystis methanotrophs. FISH confirmed the presence of both types I and II MOB in all the microsites and in the related enrichment cultures. The study reported, for the first time, the diversity of cultivable methanotrophs including a novel species of type I MOB in rice paddy field compartments. Refining growth media and culture conditions, in combination with molecular approaches, will allow us to broaden our knowledge on the MOB community in the rice paddy field ecosystem and consequently to implement strategies for mitigating CH4 emission from this ecosystem. PMID:22446309

  1. Emissions Of Greenhouse Gases From Rice Agriculture

    SciTech Connect

    M. Aslam K. Khalil

    2009-07-16

    This project produced detailed data on the processes that affect methane and nitrous oxide emissions from rice agriculture and their inter-relationships. It defines the shifting roles and potential future of these gases in causing global warming and the benefits and tradeoffs of reducing emissions. The major results include: 1). Mechanisms and Processes Leading to Methane Emissions are Delineated. Our experiments have tested the standard model of methane emissions from rice fields and found new results on the processes that control the flux. A mathematical mass balance model was used to unravel the production, oxidation and transport of methane from rice. The results suggested that when large amounts of organic matter are applied, the additional flux that is observed is due to both greater production and reduced oxidation of methane. 2). Methane Emissions From China Have Been Decreasing Over the Last Two Decades. We have calculated that methane emissions from rice fields have been falling in recent decades. This decrease is particularly large in China. While some of this is due to reduced area of rice agriculture, the bigger effect is from the reduction in the emission factor which is the annual amount of methane emitted per hectare of rice. The two most important changes that cause this decreasing emission from China are the reduced use of organic amendments which have been replaced by commercial nitrogen fertilizers, and the increased practice of intermittent flooding as greater demands are placed on water resources. 3). Global Methane Emissions Have Been Constant For More Than 20 Years. While the concentrations of methane in the atmosphere have been leveling off in recent years, our studies show that this is caused by a near constant total global source of methane for the last 20 years or more. This is probably because as some anthropogenic sources have increased, others, such as the rice agriculture source, have fallen. Changes in natural emissions appear small. 4). Nitrous Oxide Emissions From Rice Fields Increase as Methane Emissions Drop. Inundated conditions favor anaerobic methane production with high emission rates and de-nitrification resulting in modest nitrous oxide emissions. Under drier conditions such as intermittent flooding, methane emissions fall and nitrous oxide emissions increase. Increased nitrogen fertilizer use increases nitrous oxide emissions and is usually accompanied by reduced organic matter applications which decreases methane emissions. These mechanisms cause a generally inverse relationship between methane and nitrous oxide emissions. Reduction of methane from rice agriculture to control global warming comes with tradeoffs with increased nitrous oxide emissions. 5). High Spatial Resolution Maps of Emissions Produced. Maps of methane and nitrous oxide emissions at a resolution of 5 min × 5 min have been produced based on the composite results of this research. These maps are necessary for both scientific and policy uses.

  2. ECOSYSTEM GROWTH AND DEVELOPMENT

    EPA Science Inventory

    Thermodynamically, ecosystem growth and development is the process by which energy throughflow and stored biomass increase. Several proposed hypotheses describe the natural tendencies that occur as an ecosystem matures, and here, we consider five: minimum entropy production, maxi...

  3. Conservation and Management of Tropical Coastal Ecosystems

    Microsoft Academic Search

    William Gladstone

    All major coastal ecosystems in the tropics are being degraded. The problems include losses of biodiversity, reduced ecosystem\\u000a functions, and costs to coastal human societies. Declines in species’ abundances, and habitat loss and modification are the\\u000a result of the demands for aquaculture, port construction, trawling, excessive nutrient loads, overfishing and collecting,\\u000a sedimentation from catchment activities, invasive species, and climate change.

  4. Found: Rice that produces grains with improved nutritional value

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice provides the major source of nutrition for a large proportion of the world’s population, and is a key ingredient in baby foods in the U.S. Mineral nutrients such as Ca, Fe, and Zn play critical roles in human health, with over 3 billion people suffering from Fe and Zn deficiencies. Unfortunat...

  5. Chalkiness in Rice: Potential for Evaluation with Image Analysis

    Microsoft Academic Search

    Yosuke Yoshioka; Hiroyoshi Iwata; Minako Tabata; Seishi Ninomiya; Ryo Ohsawa

    2007-01-01

    Chalkiness is a major concern in rice (Oryza sativa L.) breeding because it is one of the key factors in determining quality and price. Evalu- ation of chalkiness is traditionally performed by human visual inspection, and there is no stan- dard objective method to effectively classify chalky grains into different categories. In this study, we evaluated the effectiveness of image

  6. Mitochondrial DNA modifications associated with cytoplasmic male sterility in rice

    Microsoft Academic Search

    H. Mignouna; S. S. Virmani; M. Briquet

    1987-01-01

    Mitochondrial DNA was isolated from fertile and cytoplasmic male sterile lines of rice. Restriction analysis showed specific modifications in the male sterile cytoplasm. In addition to the major mitochondrial DNA, three small plasmid-like DNA molecules were detected by agarose gel electrophoresis in both cytoplasms. An additional molecule was specifically found in the sterile cytoplasm. These mitochondrial DNA modifications support the

  7. Rheological properties of rice dough for making rice bread

    Microsoft Academic Search

    Hema P. Sivaramakrishnan; B. Senge; P. K. Chattopadhyay

    2004-01-01

    The rheological properties of two varieties of rice with Hydroxy propyl methyl cellulose (HPMC) added as gluten substitute were studied using a farinograph and a rheometer and compared with wheat dough to find its suitability for making rice bread. The water absorption and dough development time data were obtained from the farinogram. The tests conducted in the rheometer were oscillation

  8. Baltic Ecosystem Adaptive Management

    E-print Network

    1 Baltic Ecosystem Adaptive Management Research for sustainable management of the Baltic Sea #12;2 Baltic Ecosystem Adaptive Management, BEAM, is an interdisciplinary research program on ecosystem-based management of the Baltic Sea environment. The program gathers researchers from three Faculties and ten

  9. Biodiversity regulates ecosystem predictability

    Microsoft Academic Search

    Patricia M. Harris; Peter J. Morin

    1997-01-01

    1-6 . Here we describe a previously unrecognized effect of biodiversity on ecosystem predictability, where predictability is inversely related to temporal and spatial variation in ecosystem properties. By manipulating biodiversity in aquatic microbial communities, we show that one process, ecosystem respiration, becomes more predictable as biodiversity increases. Analysis of similar patterns extracted from other studies 2,3,6 indicates that biodiversity also

  10. Greater Everglades Ecosystem Restoration

    E-print Network

    Watson, Craig A.

    Greater Everglades Ecosystem Restoration (G.E.E.R.) Science Conference 'HILQLQJ6XFFHVV Naples Beach a Committee of the South Florida Ecosystem Restoration Task Force and Working Group #12;Greater Everglades Ecosystem Restoration (G.E.E.R.) Science Conference Page ii #12;December 11-15, 2000 z Naples, Florida Page

  11. Ecosystem Health: Energy Indicators.

    EPA Science Inventory

    Just as for human beings health is a concept that applies to the condition of the whole organism, the health of an ecosystem refers to the condition of the ecosystem as a whole. For this reason, the study and characterization of ecosystems is fundamental to establishing accurate ...

  12. Rice University Electrical and Computer Engineering Learn more at cmc.rice.edu

    E-print Network

    Rice University Electrical and Computer Engineering Wireless Learn more at cmc.rice.edu or ece.rice in either orthogonal time-slots (TDD) or frequency bands (FDD). In 2010, Rice re-purposed off-the-shelf MIMO Wireless project directed by Prof. Edward Knightly at Rice University aims to develop fundamental

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Ecosystem services in urban areas

    Microsoft Academic Search

    Per Bolund; Sven Hunhammar

    1999-01-01

    Humanity is increasingly urban, but continues to depend on Nature for its survival. Cities are dependent on the ecosystems beyond the city limits, but also benefit from internal urban ecosystems. The aim of this paper is to analyze the ecosystem services generated by ecosystems within the urban area. ‘Ecosystem services’ refers to the benefits human populations derive from ecosystems. Seven

  15. Environments and Ecosystems

    NSDL National Science Digital Library

    2014-09-18

    Students explore the biosphere and its associated environments and ecosystems in the context of creating a model ecosystem, learning along the way about the animals and resources. Students investigate different types of ecosystems, learn new vocabulary, and consider why a solid understanding of one's environment and the interdependence of an ecosystem can inform the choices we make and the way we engineer our communities. This lesson is part of a series of six lessons in which students use their growing understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

  16. MOLECULAR MARKERS IN RICE BREEDING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers in the USDA/TAES/TAMU Molecular Genetics Laboratory are continuing to develop and analyze markers for several economically important traits in rice. We are presently active in a multi-institute Coordinated Agricultural Project (RiceCAP) funded by the USDA National Research Initiative to ...

  17. Advances in Transgenic Rice Biotechnology

    Microsoft Academic Search

    Hitesh Kathuria; Jitender Giri; Himani Tyagi; Akhilesh K. Tyagi

    2007-01-01

    Rice is the most amenable crop plant for genetic manipulation amongst monocots due to its small genome size, enriched genetic map, availability of entire genome sequence, and relative ease of transformation. Improvement in agronomic traits of rice is bound to affect a sizeable population since it is a primary source of sustenance. Recent advances like use of ‘clean gene’ technology

  18. Genomewide SNP variation reveals relationships among landraces and modern varieties of rice

    PubMed Central

    McNally, Kenneth L.; Childs, Kevin L.; Bohnert, Regina; Davidson, Rebecca M.; Zhao, Keyan; Ulat, Victor J.; Zeller, Georg; Clark, Richard M.; Hoen, Douglas R.; Bureau, Thomas E.; Stokowski, Renee; Ballinger, Dennis G.; Frazer, Kelly A.; Cox, David R.; Padhukasahasram, Badri; Bustamante, Carlos D.; Weigel, Detlef; Mackill, David J.; Bruskiewich, Richard M.; Rätsch, Gunnar; Buell, C. Robin; Leung, Hei; Leach, Jan E.

    2009-01-01

    Rice, the primary source of dietary calories for half of humanity, is the first crop plant for which a high-quality reference genome sequence from a single variety was produced. We used resequencing microarrays to interrogate 100 Mb of the unique fraction of the reference genome for 20 diverse varieties and landraces that capture the impressive genotypic and phenotypic diversity of domesticated rice. Here, we report the distribution of 160,000 nonredundant SNPs. Introgression patterns of shared SNPs revealed the breeding history and relationships among the 20 varieties; some introgressed regions are associated with agronomic traits that mark major milestones in rice improvement. These comprehensive SNP data provide a foundation for deep exploration of rice diversity and gene–trait relationships and their use for future rice improvement. PMID:19597147

  19. NMR-based metabolic profiling of rice wines by F(2)-selective total correlation spectra.

    PubMed

    Koda, Masanori; Furihata, Kazuo; Wei, Feifei; Miyakawa, Takuya; Tanokura, Masaru

    2012-05-16

    In this study, we performed NMR-based metabolic profiling of major rice wines (Japanese sake, Chinese Shaoxing wine, and Korean makgeolli). In the (1)H NMR spectra, the rice wines showed broad resonances in the region of about 7.9-9.0 ppm. These resonances showed many and complex correlations with approximately 0.5-4.5 ppm in the F(2)-selective TOCSY (total correlation spectroscopy) spectra, and these correlations were attributed mainly to peptides. These spectral patterns were characteristic of individual rice wines, and the combination of F(2)-selective TOCSY spectra and principal component analysis enabled us to classify the rice wine species. Furthermore, it also provided information about raw materials, namely, what type of koji (rice koji or wheat koji) was used. These spectra may be useful as a new "fingerprint" for quality control or food authentication. PMID:22530947

  20. Impact of agronomic practices on arsenic accumulation and speciation in rice grain.

    PubMed

    Ma, Rui; Shen, Jianlin; Wu, Jinshui; Tang, Zhong; Shen, Qirong; Zhao, Fang-Jie

    2014-11-01

    Rice is a major source of dietary arsenic (As). The effects of paddy water management, straw incorporation, the applications of nitrogen fertilizer or organic manure, and the additions of biochar on arsenic accumulation and speciation in rice grain were investigated under field conditions over four cropping seasons in Hunan, China. Treatments that promoted anaerobic conditions in the soil, including continuous flooding and straw incorporation, significantly increased the concentration of As, especially methylated As species, in rice grain, whereas N application rate and biochar additions had little or inconsistent effect. Continuous flooding and straw incorporation also increased the abundance of the arsenite methyltransferase gene arsM in the soil, potentially enhancing As methylation in the soil and the uptake of methylated As by rice plants. Intermittent flooding was an effective method to decrease As accumulation in rice grain. PMID:25150455

  1. The evolving story of rice evolution

    Microsoft Academic Search

    Duncan A. Vaughan; Bao-Rong Lu; Norihiko Tomooka

    2008-01-01

    Recent research related to evolution in the primary gene pool of rice, which consists of Oryza species with the A-genome, provides new perspectives related to current and past eco-genetic setting of rice and its wild relatives and fresh insights into rice domestication. In Asia the traits of the rice domestication syndrome are many but due to the remarkable diversification of

  2. THE VOLATILE COMPOSITION OF WAXY RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waxy rice contains no amylose and has a characteristic aroma described as starchy/grainy. Waxy rice is used in traditional Japanese rice cakes, crackers, and is preferred for making rice wines and sake throughout the Orient. Gas chromatographic/mass spectral data showed a greater presence of lipid...

  3. RICE SEQUENCES OF RELATIONS ANTONIO MONTALBAN

    E-print Network

    Montalbán, Antonio

    RICE SEQUENCES OF RELATIONS ANTONIO MONTALB´AN Abstract. We propose a framework to study computational ways of measuring the complexity of relations. The key notion of this paper is the one of rice sequence of relations, where rice stands for relatively intrinsically computably enumerable. A rice

  4. Rice University Electrical and Computer Engineering Neuroengineering

    E-print Network

    Rice University Electrical and Computer Engineering Neuroengineering Learn more at ece.rice function. At Rice, we develop technologies to understand, repair, replace, enhance, or treat the diseases, the university has established the Rice Center for Neuroengineering (RCNE). The center's goal is to integrate

  5. CONSERVING WATER WITH MULTIPLE INLET RICE IRRIGATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice production is an important component of Arkansas' and other southern states' agriculture. In fact, when combined with the rice processing, agricultural equipment, and other businesses supporting rice production, it is apparent that rice is important to the overall economy, and not just in the r...

  6. LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1

    E-print Network

    Natelson, Douglas

    LASER SAFETY MANUAL 2014 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 January 2014 #12;LASER SAFETY MANUAL 2014 RICE UNIVERSITY 2 Introduction The objective of the Rice University Laser Safety program is to assist all levels

  7. LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1

    E-print Network

    Natelson, Douglas

    LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 December 2012 #12;LASER SAFETY MANUAL 2012 RICE at Rice University that uses Class 3B and 4 lasers. Responsibilities Laser Safety Officer (LSO) ­ The LSO

  8. Remotely sensed rice yield prediction using multi-temporal NDVI data derived from NOAA's-AVHRR.

    PubMed

    Huang, Jingfeng; Wang, Xiuzhen; Li, Xinxing; Tian, Hanqin; Pan, Zhuokun

    2013-01-01

    Grain-yield prediction using remotely sensed data have been intensively studied in wheat and maize, but such information is limited in rice, barley, oats and soybeans. The present study proposes a new framework for rice-yield prediction, which eliminates the influence of the technology development, fertilizer application, and management improvement and can be used for the development and implementation of provincial rice-yield predictions. The technique requires the collection of remotely sensed data over an adequate time frame and a corresponding record of the region's crop yields. Longer normalized-difference-vegetation-index (NDVI) time series are preferable to shorter ones for the purposes of rice-yield prediction because the well-contrasted seasons in a longer time series provide the opportunity to build regression models with a wide application range. A regression analysis of the yield versus the year indicated an annual gain in the rice yield of 50 to 128 kg ha(-1). Stepwise regression models for the remotely sensed rice-yield predictions have been developed for five typical rice-growing provinces in China. The prediction models for the remotely sensed rice yield indicated that the influences of the NDVIs on the rice yield were always positive. The association between the predicted and observed rice yields was highly significant without obvious outliers from 1982 to 2004. Independent validation found that the overall relative error is approximately 5.82%, and a majority of the relative errors were less than 5% in 2005 and 2006, depending on the study area. The proposed models can be used in an operational context to predict rice yields at the provincial level in China. The methodologies described in the present paper can be applied to any crop for which a sufficient time series of NDVI data and the corresponding historical yield information are available, as long as the historical yield increases significantly. PMID:23967112

  9. Comparative cytological and transcriptomic analysis of pollen development in autotetraploid and diploid rice.

    PubMed

    Wu, Jinwen; Shahid, Muhammad Qasim; Guo, Haibin; Yin, Wei; Chen, Zhixiong; Wang, Lan; Liu, Xiangdong; Lu, Yonggen

    2014-12-01

    Autotetraploid rice has greater genetic variation and higher vigor than diploid rice, but low pollen fertility is one of the major reasons for low yield of autotetraploid rice. Very little is known about the molecular mechanisms of low pollen fertility of autotetraploid rice. In this study, cytological observations and microarray analysis were used to assess the genetic variation during pollen development in autotetraploid and diploid rice. Many abnormal chromosome behaviors, such as mutivalents, lagged chromosomes, asynchronous cell division, and so on, were found during meiosis in autotetraploid. Microsporogenesis and microgametogenesis in autotetraploid rice was similar to diploid rice, but many different kinds of abnormalities, including microspores degeneration, multi-aperture, and abnormal cell walls, were found in autotetraploid rice. Compared with diploid rice, a total of 1,251 genes were differentially expressed in autotetraploid rice in pollen transcriptome, among them 1,011 and 240 genes were up-regulated and down-regulated, respectively. 124 and 6 genes were co-up-regulated and co-down-regulated during three pollen development stages, respectively. These results suggest that polyploidy induced up-regulation for most of the genes during pollen development. Quantitative RT-PCR was done to validate 12 differentially expressed genes selected from functional categories based on the gene ontology analysis. These stably expressed genes not only related to the pollen development genes, but also involved in cell metabolism, cell physiology, binding, catalytic activity, molecular transducer activity, and transcription regulator activity. The present study suggests that differential expression of some key genes may lead to complex gene regulation and abnormal pollen development in autotetraploid rice. PMID:25262386

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Genetic diversity for grain mineral concentrations among diverse rice germplasm grown gnder aerobic and anaerobic field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice provides the major source of nutrition for a large proportion of the world’s population. Mineral nutrients such as Ca, Fe, and Zn play critical roles in human health, with over 3 billion people suffering from Fe and Zn deficiencies. Unfortunately for those who rely on rice for subsistence, ri...

  12. Rice blast infection of Brachypodium distachyon as a model system to study dynamic host\\/pathogen interactions

    Microsoft Academic Search

    David Parker; Manfred Beckmann; David P Enot; David P Overy; Zaira Caracuel Rios; Martin Gilbert; Nicholas Talbot; John Draper

    2008-01-01

    Interactions between plants and compatible fungal pathogens are spatially and temporally dynamic, posing a major challenge for sampling and data analysis. A protocol is described for the infection of the model grass species Brachypodium distachyon with Magnaporthe grisea (rice blast), together with modifications to extend the use to rice and barley. We outline a method for the preparation of long-term

  13. PROTEOMIC AND GENETIC APPROACHES TO IDENTIFYING DEFENSE-RELATED PROTEINS IN RICE CHALLENGED WITH THE FUNGAL PATHOGEN RHIZOCTONIA SOLANI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheath blight, caused by the fungus Rhizoctonia solani, is a major disease of rice worldwide, but little is known about the host response to infection. The objective of this study was to identify proteins and DNA markers in resistant and susceptible rice associated with response to infection by R. s...

  14. Action of low temperature on physiology of Sitophilus zeamais motschulsky and Sitophilus oryzae (L.) (Coleoptera: Curculionidae) in rice storage

    Microsoft Academic Search

    Hiroshi Nakakita; Hiroshi Ikenaga

    1997-01-01

    Low temperature storage of rice is extensively practised to control insect pests in Japan, and has enabled the use of conventional fumigants to be reduced since 1991. In the present study, the action of low temperature on the physiology of Sitophilus zeamais and Sitophilus oryzae, the major insect pests on rice, was investigated. Oxygen consumption by the adults of both

  15. Confirmation of hybridization between rice and phenotypically distinct red rice types in Arkansas rice fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review details several key findings from red-rice rice outcrossing evaluations in research plots and in grower fields in Arkansas from 2000 to 2005. Observations from research plots, controlled crosses, and grower fields have provided us with several easily discernable phenotypic traits (e.g. ...

  16. CONFIRMATION OF HYBRIDIZATION BETWEEN RICE AND PHENOTYPICALLY DISTINCT RED RICE TYPES IN ARKANSAS RICE FIELDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review details several key findings from rice-red rice outcrossing evaluations in research plots and in grower fields in Arkansas from 2000 to 2005. Observations from research plots, controlled crosses, and grower fields have provided us with several easily discernable phenotypic traits (e.g. ...

  17. Identification of climate-resilient integrated nutrient management practices for rice-rice cropping system--an empirical approach to uphold food security.

    PubMed

    Subash, N; Gangwar, B; Singh, Rajbir; Sikka, A K

    2015-01-01

    Yield datasets of long-term experiments on integrated nutrient management in rice-rice cropping systems were used to investigate the relationship of variability in rainfall, temperature, and integrated nutrient management (INM) practices in rice-rice cropping system in three different agroecological regions of India. Twelve treatments with different combinations of inorganic (chemical fertilizer) and organic (farmyard manure, green manure, and paddy straw) were compared with farmer's conventional practice. The intraseasonal variations in rice yields are largely driven by rainfall during kharif rice and by temperature during rabi rice. Half of the standard deviation from the average monthly as well as seasonal rainfall during kharif rice and 1 °C increase or decrease from the average maximum and minimum temperature during rabi rice has been taken as the classification of yield groups. The trends in the date of effective onset of monsoon indicate a 36-day delay during the 30-year period at Rajendranagar, which is statistically significant at 95 % confidence level. The mean annual maximum temperature shows an increasing trend in all the study sites. The length of monsoon also showed a shrinking trend in the rate of 40 days during the 30-year study period at Rajendranagar representing a semiarid region. At Bhubaneshwar, the application of 50 % recommended NPK through chemical fertilizers and 50 % N through green manure resulted in an overall average higher increase of 5.1 % in system productivity under both excess and deficit rainfall years and also during the years having seasonal mean maximum temperature ?35 °C. However, at Jorhat, the application of 50 % recommended NPK through chemical fertilizers and 50 % N through straw resulted in an overall average higher increase of 7.4 % in system productivity, while at Rajendranagar, the application of 75 % NPK through chemical fertilizers and 25 % N through green manusre resulted in an overall average higher increase of 8.8 % in system productivity. This study highlights the adaptive capacity of different integrated nutrient management practices to rainfall and temperature variability under a rice-rice cropping system in humid, subhumid, and semiarid ecosystems. PMID:24817490

  18. Identification of climate-resilient integrated nutrient management practices for rice-rice cropping system—an empirical approach to uphold food security

    NASA Astrophysics Data System (ADS)

    Subash, N.; Gangwar, B.; Singh, Rajbir; Sikka, A. K.

    2015-01-01

    Yield datasets of long-term experiments on integrated nutrient management in rice-rice cropping systems were used to investigate the relationship of variability in rainfall, temperature, and integrated nutrient management (INM) practices in rice-rice cropping system in three different agroecological regions of India. Twelve treatments with different combinations of inorganic (chemical fertilizer) and organic (farmyard manure, green manure, and paddy straw) were compared with farmer's conventional practice. The intraseasonal variations in rice yields are largely driven by rainfall during kharif rice and by temperature during rabi rice. Half of the standard deviation from the average monthly as well as seasonal rainfall during kharif rice and 1 °C increase or decrease from the average maximum and minimum temperature during rabi rice has been taken as the classification of yield groups. The trends in the date of effective onset of monsoon indicate a 36-day delay during the 30-year period at Rajendranagar, which is statistically significant at 95 % confidence level. The mean annual maximum temperature shows an increasing trend in all the study sites. The length of monsoon also showed a shrinking trend in the rate of 40 days during the 30-year study period at Rajendranagar representing a semiarid region. At Bhubaneshwar, the application of 50 % recommended NPK through chemical fertilizers and 50 % N through green manure resulted in an overall average higher increase of 5.1 % in system productivity under both excess and deficit rainfall years and also during the years having seasonal mean maximum temperature ?35 °C. However, at Jorhat, the application of 50 % recommended NPK through chemical fertilizers and 50 % N through straw resulted in an overall average higher increase of 7.4 % in system productivity, while at Rajendranagar, the application of 75 % NPK through chemical fertilizers and 25 % N through green manusre resulted in an overall average higher increase of 8.8 % in system productivity. This study highlights the adaptive capacity of different integrated nutrient management practices to rainfall and temperature variability under a rice-rice cropping system in humid, subhumid, and semiarid ecosystems.

  19. International Consortium of Rice Mutagenesis: resources and beyond

    PubMed Central

    2013-01-01

    Rice is one of the most important crops in the world. The rice community needs to cooperate and share efforts and resources so that we can understand the functions of rice genes, especially those with a role in important agronomical traits, for application in agricultural production. Mutation is a major source of genetic variation that can be used for studying gene function. We will present here the status of mutant collections affected in a random manner by physical/chemical and insertion mutageneses. As of early September 2013, a total of 447, 919 flanking sequence tags from rice mutant libraries with T-DNA, Ac/Ds, En/Spm, Tos17, nDART/aDART insertions have been collected and publicly available. From these, 336,262 sequences are precisely positioned on the japonica rice chromosomes, and 67.5% are in gene interval. We discuss the genome coverage and preference of the insertion, issues limiting the exchange and use of the current collections, as well as new and improved resources. We propose a call to renew all mutant populations as soon as possible. We also suggest that a common web portal should be established for ordering seeds. PMID:24341871

  20. Aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference

    PubMed Central

    Zhao, Xue Qiang; Guo, Shi Wei; Shinmachi, Fumie; Sunairi, Michio; Noguchi, Akira; Hasegawa, Isao; Shen, Ren Fang

    2013-01-01

    Background and Aims Acidic soils are dominated chemically by more ammonium and more available, so more potentially toxic, aluminium compared with neutral to calcareous soils, which are characterized by more nitrate and less available, so less toxic, aluminium. However, it is not known whether aluminium tolerance and nitrogen source preference are linked in plants. Methods This question was investigated by comparing the responses of 30 rice (Oryza sativa) varieties (15 subsp. japonica cultivars and 15 subsp. indica cultivars) to aluminium, various ammonium/nitrate ratios and their combinations under acidic solution conditions. Key Results indica rice plants were generally found to be aluminium-sensitive and nitrate-preferring, while japonica cultivars were aluminium-tolerant and relatively ammonium-preferring. Aluminium tolerance of different rice varieties was significantly negatively correlated with their nitrate preference. Furthermore, aluminium enhanced ammonium-fed rice growth but inhibited nitrate-fed rice growth. Conclusions The results suggest that aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference under acidic solution conditions. A schematic diagram summarizing the interactions of aluminium and nitrogen in soil–plant ecosystems is presented and provides a new basis for the integrated management of acidic soils. PMID:23118122

  1. Methane emission from fields with three various rice straw treatments in Taiwan paddy soils.

    PubMed

    Liou, Rey-May; Huang, Shan-Ney; Lin, Chin-Wei; Chen, Shin-Hsiung

    2003-07-01

    Flooded rice fields are one of the major biogenic methane sources. In this study, the effects of straw residual treatments on methane emission from paddy fields were discussed. The experimental field was located at Tainan District Agricultural Improvement Station in Chia-Yi county (23 degrees 25'08''N, 120degrees16'26''E) of southern Taiwan throughout the first and the second crop seasons in 2000. The seasonal methane fluxes in the first crop season with rice stubble removed, rice straw burned and rice straw incorporated were 4.41, 3.78 and 5.27 g CH4 m(-2), and the values were 32.8, 38.9 and 75.1 g CH4 m(-2) in the second crop season, respectively. In comparison of three management methods of rice straw residue, the incorporation of rice straw residue should show a significant tendency for enhancing methane emission in the second crop season. Moreover, stubble removed and straw burned treatments significantly reduced CH4 emissions by 28 approximately 56% emissions compared to straw incorporated plot. Concerning for air quality had led to legislation restricting rice straw burning, removing of rice stubble might be an appropriate methane mitigation strategy in Taiwan paddy soils. PMID:12856932

  2. Chinese rice production area adaptations to climate changes, 1949-2010.

    PubMed

    Li, Zhengguo; Liu, Zhenhuan; Anderson, Weston; Yang, Peng; Wu, Wenbin; Tang, Huajun; You, Liangzhi

    2015-02-17

    Climate change has great impact on cropping system. Understanding how the rice production system has historically responded to external forces, both natural and anthropogenic, will provide critical insights into how the system is likely to respond in the future. The observed historic rice movement provides insights into the capability of the rice production system to adapt to climate changes. Using province-level rice production data and historic climate records, here we show that the centroid of Chinese rice production shifted northeastward over 370km (2.98°N in latitude and 1.88°E in longitude) from 1949 to 2010. Using a linear regression model, we examined the driving factors, in particular climate, behind such rice production movement. While the major driving forces of the rice relocation are such social economic factors as urbanization, irrigation investment, and agricultural or land use policy changes, climate plays a significant role as well. We found that temperature has been a significant and coherent influence on moving the rice center in China and precipitation has had a significant but less spatially coherent influence. PMID:25625767

  3. Gibberellin biosynthesis and signal transduction is essential for internode elongation in deepwater rice.

    PubMed

    Ayano, Madoka; Kani, Takahiro; Kojima, Mikiko; Sakakibara, Hitoshi; Kitaoka, Takuya; Kuroha, Takeshi; Angeles-Shim, Rosalyn B; Kitano, Hidemi; Nagai, Keisuke; Ashikari, Motoyuki

    2014-10-01

    Under flooded conditions, the leaves and internodes of deepwater rice can elongate above the water surface to capture oxygen and prevent drowning. Our previous studies showed that three major quantitative trait loci (QTL) regulate deepwater-dependent internode elongation in deepwater rice. In this study, we investigated the age-dependent internode elongation in deepwater rice. We also investigated the relationship between deepwater-dependent internode elongation and the phytohormone gibberellin (GA) by physiological and genetic approach using a QTL pyramiding line (NIL-1?+?3?+?12). Deepwater rice did not show internode elongation before the sixth leaf stage under deepwater condition. Additionally, deepwater-dependent internode elongation occurred on the sixth and seventh internodes during the sixth leaf stage. These results indicate that deepwater rice could not start internode elongation until the sixth leaf stage. Ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS) method for the phytohormone contents showed a deepwater-dependent GA1 and GA4 accumulation in deepwater rice. Additionally, a GA inhibitor abolished deepwater-dependent internode elongation in deepwater rice. On the contrary, GA feeding mimicked internode elongation under ordinary growth conditions. However, mutations in GA biosynthesis and signal transduction genes blocked deepwater-dependent internode elongation. These data suggested that GA biosynthesis and signal transduction are essential for deepwater-dependent internode elongation in deepwater rice. PMID:24891164

  4. Genomics-based precision breeding approaches to improve drought tolerance in rice.

    PubMed

    Swamy, B P Mallikarjuna; Kumar, Arvind

    2013-12-01

    Rice (Oryza sativa L.), the major staple food crop of the world, faces a severe threat from widespread drought. The development of drought-tolerant rice varieties is considered a feasible option to counteract drought stress. The screening of rice germplasm under drought and its characterization at the morphological, genetic, and molecular levels revealed the existence of genetic variation for drought tolerance within the rice gene pool. The improvements made in managed drought screening and selection for grain yield under drought have significantly contributed to progress in drought breeding programs. The availability of rice genome sequence information, genome-wide molecular markers, and low-cost genotyping platforms now makes it possible to routinely apply marker-assisted breeding approaches to improve grain yield under drought. Grain yield QTLs with a large and consistent effect under drought have been indentified and successfully pyramided in popular rice mega-varieties. Various rice functional genomics resources, databases, tools, and recent advances in "-omics" are facilitating the characterization of genes and pathways involved in drought tolerance, providing the basis for candidate gene identification and allele mining. The transgenic approach is successful in generating drought tolerance in rice under controlled conditions, but field-level testing is necessary. Genomics-assisted drought breeding approaches hold great promise, but a well-planned integration with standardized phenotyping is highly essential to exploit their full potential. PMID:23702083

  5. Texas Rice Production Guidelines

    E-print Network

    Way, M. O.; Cockrell, Jay

    2008-03-11

    Cooperative Extension, the Texas Agricultural Experiment Station and the United States Department of Agriculture/Agricultural Research Service is implied. Photo credits On the cover, top to bottom: Planting research plots for the Uniform Regional Rice Nursery...-eason@aesrg.tamu.edu ***Dr. William D. ?Bill? Park Associate Dept. Head, Graduate Studies Crop Biotechnology 979.845.8868 wdpark@tamu.edu *Dr. Garry McCauley Professor Water and Weed Management 979.234.3578 gnmccaule@sbcglobal.net Dr. Omar Samonte Assistant Plant Breeder...

  6. One Grain of Rice

    NSDL National Science Digital Library

    Christy Simon

    2000-01-01

    Beginning with the famous story of the village girl trying to feed her people, the lesson involves students in the mathematics of exponential growth. Students work collaboratively to come up with a bargaining plan to trick a raja into feeding the village using algebra and estimation. The complete activity includes the development of an exponential equation, but just following the growth of the number of rice grains throughout the story gives a good introduction to exponential growth. Questions for students and ideas for assessment are provided.

  7. Allelic diversities in rice starch biosynthesis lead to a diverse array of rice eating and cooking qualities

    PubMed Central

    Tian, Zhixi; Qian, Qian; Liu, Qiaoquan; Yan, Meixian; Liu, Xinfang; Yan, Changjie; Liu, Guifu; Gao, Zhenyu; Tang, Shuzhu; Zeng, Dali; Wang, Yonghong; Yu, Jianming; Gu, Minghong; Li, Jiayang

    2009-01-01

    More than half of the world's population uses rice as a source of carbon intake every day. Improving grain quality is thus essential to rice consumers. The three main properties that determine rice eating and cooking quality—amylose content, gel consistency, and gelatinization temperature—correlate with one another, but the underlying mechanism of these properties remains unclear. Through an association analysis approach, we found that genes related to starch synthesis cooperate with each other to form a fine regulating network that controls the eating and cooking quality and defines the correlation among these three properties. Genetic transformation results verified the association findings and also suggested the possibility of developing elite cultivars through modification with selected major and/or minor starch synthesis-related genes. PMID:20018713

  8. SAR Agriculture Rice Production Estimation (SARPE)

    NASA Astrophysics Data System (ADS)

    Raimadoya, M.

    2013-12-01

    The study of SAR Agriculture Rice Production Estimation (SARPE) was held in Indonesia on 2012, as part of Asia-Rice Crop Estimation & Monitoring (Asia-RiCE), which is a component for the GEO Global Agricultural Monitoring (GEOGLAM) initiative. The study was expected to give a breakthrough result, by using radar technology and paradigm shift of the standard production estimation system from list frame to area frame approach. This initial product estimation system is expected to be refined (fine tuning) in 2013, by participating as part of Technical Demonstration Site (Phase -1A) of Asia-RICE. The implementation period of this initial study was from the date of March 12 to December 10, 2012. The implementation of the study was done by following the approach of the BIMAS-21 framework, which has been developed since 2008. The results of this study can be briefly divided into two major components, namely: Rice-field Baseline Mapping (PESBAK - Peta Sawah Baku) and Crop Growth Monitoring. Rice-fields were derived from the mapping results of the Ministry of Agriculture (Kemtan), and validated through Student Extension Campaign of the Faculty of Agriculture, Bogor Agricultural University (IPB). While for the crop growth, it was derived from the results of image analysis process. The analysis was done, either on radar/Radarsat-2 (medium resolution) or optical/ MODIS (low resolution), based on the Planting Calendar (KATAM) of Kemtan. In this case, the planting season II/2012-2013 of rice production centers in West Java Province (Karawang, Subang and Indramayu counties). The selection of crop season and county were entirely dependent on the quality of the available PESBAK and procurement process of radar imagery. The PESBAK is still in the form of block instead of fields, so it can not be directly utilized in this study. Efforts to improve the PESBAK can not be optimal because the provided satellite image (ECW format) is not the original one. While the procurement process of SAR imageries, determine the target planting season to be linked. In this case the radar image only acquired two time series: the date of 26/10/2012 (stripmap) and 10/31/2012 (scanSAR) for series-1, and the date of 19/11/2012 (stripmap) and 11/24/2012 ( scanSAR) for series-2. The end result of this study is a model of crop growth status at the village, district and county level compared to KATAM. The County of Subang was used as a pilot exercise, and then was replicated into the two other counties (Karawang and Indramayu). Status of plant growth is divided into five phases: fallow wet, young vegetation, old vegetation, generative (pre-harvest), and dry fallow. The process of plant growth status was started with the determination of the majority in each rice field as a benchmark. This was followed by the creation of status recapitulation at the village, district, and ultimately at the county level. The county results were then compared with KATAM. Further replication to the rest of the other counties in the West Java Province, can only be done after the related PESBAK was improved in accordance to the area base standard requirement.

  9. Suppressive subtraction hybridization reveals that rice gall midge attack elicits plant-pathogen-like responses in rice.

    PubMed

    Rawat, Nidhi; Himabindu, Kudapa; Neeraja, Chiruvuri Naga; Nair, Suresh; Bentur, Jagadish S

    2013-02-01

    The Asian rice gall midge, Orseolia oryzae (Diptera: Cecidomyiidae), is the third most destructive insect pest of rice (Oryza sativa L.). Till date, 11 gall midge resistance gene loci have been characterized in different rice varieties. To elucidate molecular basis of incompatible (hypersensitive response plus [HR+] type) and compatible rice-gall midge interactions, two suppressive subtraction hybridization cDNA libraries were constructed. These were enriched for differentially expressed transcripts after gall midge infestation in two rice varieties (resistant Suraksha and susceptible TN1). In total, 2784 ESTs were generated and sequenced from the two libraries, of which 1536 were from the resistant Suraksha and 1248 were from the susceptible TN1. Majority (80%) of the ESTs was non-redundant sequences with known functions and was classified into three principal gene ontology (GO) categories and 12 groups. Upregulation of NBS-LRR, Cytochrome P450, heat shock proteins, phenylalanine ammonia lyase and OsPR10? genes from the Suraksha library, as revealed by real-time PCR, indicated that R gene mediated, salicylic acid related defense pathway is likely to be involved in gall midge resistance. Present study suggested that resistance in Suraksha against gall midge is similar in nature to the resistance observed in plants against pathogens. However, in TN1, genes related to primary metabolism and redox were induced abundantly. Results suggested that genes encoding translationally controlled tumor protein and NAC domain proteins are likely to be involved in the gall midge susceptibility. PMID:23257077

  10. Global Conservation of Biodiversity and Ecosystem Services

    NSDL National Science Digital Library

    Will Turner (University of the Philippines; World Agroforestry Center)

    2007-11-01

    This peer-reviewed article from the November 2007 issue of BioScience examines conservation strategies to preserve biodiversity and ecosystem services.Habitat destruction has driven much of the current biodiversity extinction crisis, and it compromises the essential benefits, or ecosystem services, that humans derive from functioning ecosystems. Securing both species and ecosystem services might be accomplished with common solutions. Yet it is unknown whether these two major conservation objectives coincide broadly enough worldwide to enable global strategies for both goals to gain synergy. In this article, we assess the concordance between these two objectives, explore how the concordance varies across different regions, and examine the global potential for safeguarding biodiversity and ecosystem services simultaneously. We find that published global priority maps for biodiversity conservation harbor a disproportionate share of estimated terrestrial ecosystem service value (ESV). Overlap of biodiversity priorities and ESV varies among regions, and in areas that have high biodiversity priority but low ESV, specialized conservation approaches are necessary. Overall, however, our findings suggest opportunities for safeguarding both biodiversity and ecosystem services. Sensitivity analyses indicate that results are robust to known limitations of available ESV data. Capitalizing on these opportunities will require the identification of synergies at fine scales, and the development of economic and policy tools to exploit them.

  11. Multiple states in river and lake ecosystems.

    PubMed Central

    Dent, C Lisa; Cumming, Graeme S; Carpenter, Stephen R

    2002-01-01

    Nonlinear models of ecosystem dynamics that incorporate positive feedbacks and multiple, internally reinforced states have considerable explanatory power. However, linear models may be adequate, particularly if ecosystem behaviour is primarily controlled by external processes. In lake ecosystems, internal (mainly biotic) processes are thought to have major impacts on system behaviour, whereas in rivers, external (mainly physical) factors have traditionally been emphasized. We consider the hypothesis that models that exhibit multiple states are useful for understanding the behaviour of lake ecosystems, but not as useful for understanding stream ecosystems. Some of the best-known examples of multiple states come from lake ecosystems. We review some of these examples, and we also describe examples of multiple states in rivers. We conclude that the hypothesis is an oversimplification; the importance of physical forcing in rivers does not eliminate the possibility of internal feedbacks that create multiple states, although in rivers these feedbacks are likely to include physical as well as biotic processes. Nonlinear behaviour in aquatic ecosystems may be more common than current theory indicates. PMID:12079525

  12. Coral Reef Ecosystems

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2007-03-28

    The Coral Reef Ecosystems SciPack explores the unique and diverse ecosystem of the coral reef. The focus is on Standards and Benchmarks related to populations and ecosystems using coral reefs and their immediate environment as an example. Because the Standards and Benchmarks present the concepts of populations and ecosystems generically, without reference to a specific ecosystem or the organisms in the system, coral reefs are used to provide the context through which concepts in a marine ecosystem are explored.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Coral Reef Ecosystems: The Living Reef? Identify coral polyp structures and describe their functions.? Describe photosynthesis in the coral environment.? Describe the evolution of a typical reef system.? Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. ? Describe the process of coral polyp reproduction and growth.? Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.Coral Reef Ecosystems: The Abiotic Setting? Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.? Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.? Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).? Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.Coral Reef Ecosystems: Interdependence? Identify and label key components of food chains and food webs in a coral reef ecosystem.? Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).? Recognize the direction that energy travels through food chains and food webs.? Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.? Describe the primary ecological succession events within a typical coral reef ecosystem.Coral Reef Ecosystems: Ecosystems in Crisis? Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).? Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).? Explain how human activity may decrease the reefs ability to recover from natural occurrences. ? Explain the effects of increased predation or disease on a reef ecosystem.? Describe the effect of habitat loss on the reef ecosystem.? Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

  13. Comparison of partial and complete soil K budgets under intensive rice cropping in the Mekong Delta, Vietnam

    Microsoft Academic Search

    Nguyen My Hoa; Bert H. Janssen; Oene Oenema; Achim Dobermann

    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 countries. Prediction of possible K deficiency in the future requires knowledge

  14. Patterns of Allozyme Variation at Two Stages of the Life History in Wild Rice Oryza rufipogon and Conservation Genetic Implications

    Microsoft Academic Search

    L. Z. Gao; D. Y. Hong; S. Ge

    2005-01-01

    Oryza rufipogon Griff. occurs widely in aquatic ecosystem of tropics and subtropics of monsoon Asia as well as Southern China. It is a vital gene source for rice breeding programs. Many populations of the species, unfortunately, have drastically diminished because of the disappearance of aquatic habitats as a result of human disturbance. In order to determine patterns of genetic variation

  15. TOWARDS POSITIONAL CLONING OF GENES FOR DORMANCY AND ITS RELATED ADAPTIVE TRAITS FROM WEEDY RICE (ORYZA SATIVA L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An array of physiological and morphological traits, such as seed dormancy, shattering and appendages, and pigmentations on seed covering tissues contribute to the adaptation of weeds in agro-ecosystems. We have developed weedy rice (Oryza sativa) as an experimental system primarily to investigate ge...

  16. Baltic Ecosystem Adaptive Management

    E-print Network

    1 Baltic Ecosystem Adaptive Management �stersjöforskning för en hållbar förvaltning av havet #12;2 Baltic Ecosystem Adaptive Management, BEAM, är ett tvärvetenskapligt forskningsprogram med målet att vårt unika innanhav beror mycket på hur vi väljer att vårda det. Baltic Ecosystem Adaptive Management

  17. Rice University | Faculty/Researchers Office of Institutional

    E-print Network

    Richards-Kortum, Rebecca

    Rice University | Faculty/Researchers Office of Institutional Research Quick Facts Rice Facts Historical Facts Archives About OIR The Office of Institutional Research (OIR) serves Rice University of information to Rice about itself. This organizational intelligence function reflects the demand

  18. Varieties of Rice for Texas.

    E-print Network

    Wyche, R. H. (Robert Henry); Beachell, H. M. (Henry Monroe)

    1933-01-01

    30. The short-grain rices are not planted to any great extent in this region. The planting of the short-grain types should continue to be limited to the demand for this type of rice; however, Caloro, Piniling Daniel, and Acadia are good short... I -- T. S. No. Variety Pounds rough rice per acre Louisiana Pearl Nazlampas Naguyon No. 8 No. 30 No. 32 Nugengwa 2000 Pei Gya Nun 2186 Polopot Piniling Daniel Quinalibo Quinamalig 1165 Rexoro Sam Sai 2328 Schindano 216E Shinriki...

  19. Fertilizers for Rice in Texas.

    E-print Network

    Wyche, R. H. (Robert Henry)

    1941-01-01

    in the rice-growing area, however, dif- ferent soils responded differently to fertilizers applied to rice. In the experiments on Lake Charles clay soil near Devers, in Liberty County, and on the light-colored soils in Orange County, applications of super... on Lake Charles and Crowley clay soils that have been grown to rice every second or third year for a long time, nitrogen (in sulfate of ammonia) gave better results than super- phosphate. In all of these cooperative experiments a combination of sulfate...

  20. Rice crop monitoring with multitemporal MODIS-Landsat data fusion

    NASA Astrophysics Data System (ADS)

    Chen, Cheng-Ru; Chen, Chi-Farn; Son, Nguyen-Thanh

    2014-05-01

    Rice is one of the most important cereal crops in the world and is the major crop in Taiwan. However, it is a challenge because rice fields are generally small and fragmental, while crop mapping requires information of crop phenology associating with the high spatiotemporal resolution of remote-sensing data. This problem can be partially overcome by a spatiotemporal fusion to create a new dataset that has a better spatiotemporal resolution. In this study, the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat imageries were used because MODIS data, which a spatial resolution of land bands of 500 m and temporal resolution of 1-2 days, were able to achieve the phenological information of rice crops at a large region; while Landsat data demonstrate the effectiveness to collectively map small patches of crop fields at the subnational level due to its spatial resolution of 30 m. However, the temporal resolution of Landsat data is lower (16 days), making it difficult to investigate temporal responses of crop phenology from rice fields. The main objective of this study was to take into account of advantages of MODIS and Landsat imageries to generate a synthetic dataset at Landsat spatial resolution and MODIS temporal resolution for rice crop mapping in Taiwan. The methodology comprised five steps: (1) satellite data for 2011 were pre-processed to account for geometric and radiometric correction of MODIS and Landsat data, (2) MODIS-Landsat data fusion using the Spatial Temporal Adaptive Fusion Model (STARFM), (3) construct the smooth time-series Normalized Difference Vegetation Index (NDVI) data using wavelet transform, (4) rice crop classification using phenological information of crop phenology, and (5) accuracy assessment. The data fusion results for day of year (DOY) 153 were compared with the reference Landsat data (DOY 153) indicated a close correlation (R2 = 0.81). The phenology-based classification results compared with the ground reference data revealed close agreement between these two datasets. The overall accuracy and Kappa coefficient were 82% and 0.75, respectively. The relationship between the MODIS-derived rice areas and those from the government's rice area statistics at the district level was examined, reaffirming a strong correlation between the two datasets with R2 > 0.9. This study demonstrates advantages of MODIS-Landsat data fusion for rice crop mapping in Taiwan. Such an approach used in this study could be applied for other regions to map small patches of crops at a subnational scale.

  1. Soil to rice transfer factors for (226)Ra, (228)Ra, (210)Pb, (40)K and (137)Cs: a study on rice grown in India.

    PubMed

    Karunakara, N; Rao, Chetan; Ujwal, P; Yashodhara, I; Kumara, Sudeep; Ravi, P M

    2013-04-01

    India is the second largest producer of rice (Oryza sativa L.) in the world and rice is an essential component of the diet for a majority of the population in India. However, detailed studies aimed at the evaluation of radionuclide transfer factors (F(v)) for the rice grown in India are almost non-existent. This paper presents the soil to rice transfer factors for natural ((226)Ra, (228)Ra, (40)K, and (210)Pb) and artificial ((137)Cs) radionuclides for rice grown in natural field conditions on the West Coast of India. A rice field was developed very close to the Kaiga nuclear power plant and the water required for this field was drawn from the cooling water discharge canal of the power plant. For a comparative study of the radionuclide transfer factors, rice samples were also collected from the rice fields of nearby villages. The study showed that the (226)Ra and (228)Ra activity concentrations were below detection levels in different organs of the rice plant. The soil to un-hulled rice grain (40)K transfer factor varied in the range of 6.5 × 10(-1) to 2.9 with a mean of 0.15 × 10(1), and of (210)Pb varied in the range of <1.2 × 10(-2) to 8.1 × 10(-1) with a mean of 1.4 × 10(-1), and of (137)Cs varied in the range of 6.6 × 10(-2) to 3.4 × 10(-1) with a mean of 2.1 × 10(-1). The mean values of un-hulled grain to white rice processing retention factors (F(r)) were 0.12 for (40)K, 0.03 for (210)Pb, and 0.14 for (137)Cs. Using these processing retention factors, the soil to white rice transfer factors were estimated and these were found to have mean values of 1.8 × 10(-1), 4.2 × 10(-3), and 3.0 × 10(-2) for (40)K, (210)Pb, and (137)Cs, respectively. The study has shown that the transfer of (40)K was higher for above the ground organs than for the root, but (210)Pb and (137)Cs were retained in the root and their transfer to above the ground organs of the rice plant is significantly lower. PMID:23266913

  2. Against the grain: safeguarding rice from rice blast disease.

    PubMed

    Skamnioti, Pari; Gurr, Sarah J

    2009-03-01

    Rice is the staple diet of more than three billion people. Yields must double over the next 40 years if we are to sustain the nutritional needs of the ever-expanding global population. Between 10% and 30% of the annual rice harvest is lost due to infection by the rice blast fungus Magnaporthe oryzae. Evaluation of genetic and virulence diversity of blast populations with diagnostic markers will aid disease management. We review the M. oryzae species-specific and cultivar-specific avirulence determinants and evaluate efforts towards generating durable and broad-spectrum resistance in single resistant cultivars or mixtures. We consider modern usage of fungicides and plant defence activators, assess the usefulness of biological control and categorize current approaches towards blast-tolerant genetically modified rice. PMID:19187990

  3. Living Things: Habitats & Ecosystems

    NSDL National Science Digital Library

    2009-01-01

    Text and photographs regarding habitats, populations and communities, biomes, niches and ecosystems in general with numerous links to lessons, activities, and organizations on specific subtopics in ecology.

  4. A comparison of rice chloroplast genomes.

    PubMed

    Tang, Jiabin; Xia, Hong'ai; Cao, Mengliang; Zhang, Xiuqing; Zeng, Wanyong; Hu, Songnian; Tong, Wei; Wang, Jun; Wang, Jian; Yu, Jun; Yang, Huanming; Zhu, Lihuang

    2004-05-01

    Using high quality sequence reads extracted from our whole genome shotgun repository, we assembled two chloroplast genome sequences from two rice (Oryza sativa) varieties, one from 93-11 (a typical indica variety) and the other from PA64S (an indica-like variety with maternal origin of japonica), which are both parental varieties of the super-hybrid rice, LYP9. Based on the patterns of high sequence coverage, we partitioned chloroplast sequence variations into two classes, intravarietal and intersubspecific polymorphisms. Intravarietal polymorphisms refer to variations within 93-11 or PA64S. Intersubspecific polymorphisms were identified by comparing the major genotypes of the two subspecies represented by 93-11 and PA64S, respectively. Some of the minor genotypes occurring as intravarietal polymorphisms in one variety existed as major genotypes in the other subspecific variety, thus giving rise to intersubspecific polymorphisms. In our study, we found that the intersubspecific variations of 93-11 (indica) and PA64S (japonica) chloroplast genomes consisted of 72 single nucleotide polymorphisms and 27 insertions or deletions. The intersubspecific polymorphism rates between 93-11 and PA64S were 0.05% for single nucleotide polymorphisms and 0.02% for insertions or deletions, nearly 8 and 10 times lower than their respective nuclear genomes. Based on the total number of nucleotide substitutions between the two chloroplast genomes, we dated the divergence of indica and japonica chloroplast genomes as occurring approximately 86,000 to 200,000 years ago. PMID:15122023

  5. Rice-Map: a new-generation rice genome browser

    Microsoft Academic Search

    Jun Wang; Lei Kong; Shuqi Zhao; He Zhang; Liang Tang; Zhe Li; Xiaocheng Gu; Jingchu Luo; Ge Gao

    2011-01-01

    Background  The concurrent release of rice genome sequences for two subspecies (Oryza sativa L. ssp. japonica and Oryza sativa L. ssp. indica) facilitates rice studies at the whole genome level. Since the advent of high-throughput analysis, huge amounts of functional\\u000a genomics data have been delivered rapidly, making an integrated online genome browser indispensable for scientists to visualize\\u000a and analyze these data.

  6. Isolation and identification of phenolic antioxidants in black rice bran.

    PubMed

    Jun, Hyun-Il; Shin, Jae-Wook; Song, Geun-Seoup; Kim, Young-Soo

    2015-02-01

    Black rice bran contains phenolic compounds of a high antioxidant activity. In this study, the 40% acetone extract of black rice bran was sequentially fractionated to obtain 5 fractions. Out of the 5 fractions, ethyl acetate fraction was subfractionated using the Sephadex LH-20 chromatography. The antioxidant activity of phenolic compounds in the extracts was investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, 2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulfonic acid) (ABTS) radical cation assay, reducing power. The subfraction 2 from ethyl acetate fraction had the highest total phenolic contents (TPC) (816.0 ?g/mg) and the lowest EC50 values (47.8 ?g/mL for DPPH radical assay, 112.8 ?g/mL for ABTS radical cation assay, and 49.2 ?g/mL for reducing power). These results were 3.1, 1.3, and 2.6 times lower than those of butylated hydroxytoluene (BHT), respectively. At a concentration of 100 ?g/mL, the antioxidant activity and TPC of various extracts was closely correlated, with correlation coefficients (R(2) ) higher than 0.86. The major phenolic acid in subfraction 2 was identified as ferulic acid (178.3 ?g/mg) by HPLC and LC-ESI/MS/MS analyses. Our finding identified ferulic acid as a major phenolic compound in black rice bran, and supports the potential use of black rice bran as a natural source of antioxidant. PMID:25597516

  7. Major Programs

    Cancer.gov

    The Division of Cancer Prevention supports major scientific collaborations and research networks at more than100 sites across the United States; investigator-initiated grants; postdoctoral training; and specialized resources for researchers.

  8. Coral Reef Ecosystems

    NASA Astrophysics Data System (ADS)

    Yap, Helen T.

    Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

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

    PubMed

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

    2012-09-01

    In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species. PMID:22943781

  10. Ecosystem Approaches for Fisheries Management 609 Alaska Sea Grant College Program AK-SG-99-01, 1999

    E-print Network

    Ecosystem Approaches for Fisheries Management 609 Alaska Sea Grant College Program · AK-SG-99-01, 1999 Ecosystem Considerations and the Limitations of Ecosystem Models in Fisheries Management: Insights for the implementation of ecosystem approaches. The major criticism of single- species models is that they cannot predict

  11. The isolation and characterization of plastid DNA from rice (Oryza sativa)

    E-print Network

    Scheuring, Chantel Fougeron

    1987-01-01

    THE ISOLATION AND CHARACTERIZATION OF PLASTID DNA FROM RICE (ORYZA SATIVA) A Thesis by CHANTEL FOUGERON SCHEURING Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1987 Major Subject: Genetics THE ISOLATION AND CHARACTERIZATION OF PLASTID DNA FROM RICE (ORYZA SATIVA) by ~L FOUGERON SCHEURING Approved as to style and content by: a' (Chairman) C J. C ghton Miller, Jr. David O. Peterson (Member...

  12. Genetic engineering approaches to improve the bioavailability and the level of iron in rice grains

    Microsoft Academic Search

    P. Lucca; R. Hurrell; I. Potrykus

    2001-01-01

    Iron deficiency is the most widespread micronutrient deficiency world-wide. A major cause is the poor absorption of iron from\\u000a cereal and legume-based diets high in phytic acid. We have explored three approaches for increasing the amount of iron absorbed\\u000a from rice-based meals. We first introduced a ferritin gene from Phaseolus vulgaris into rice grains, increasing their iron content up to

  13. Moisture levels at which rice grains will not fissure from moisture adsorption

    E-print Network

    Kamau, John Mugeto

    1985-01-01

    MOISTURE LEVELS AT WHICH RICE GRAINS WILL NOT FISSURE FROM MOISTURE ADSORPTION A Thesis JOHN MUGETO KAMAU Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1985 Major Subject: Agricultural Engineering MOISTURE LEVELS AT WHICH RICE GRAINS WILL NQT FISSURE FROM MOISTURE ADSORPTION A Thesis JOHN MUGETO KAMAU Approved as to style and content by: Otto R. Kunze (Chairman of Committee) Calvin B...

  14. Responses of High Biomass Rice (Oryza sativa L.) to Various Abiotic Stresses

    E-print Network

    Kondhia, Aditi Nitinkumar

    2011-10-21

    iii RESPONSES OF HIGH BIOMASS RICE (ORYZA SATIVA L.) TO VARIOUS ABIOTIC STRESSES A Thesis by ADITI NITINKUMAR KONDHIA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 2010 Major Subject: Plant Breeding iv Responses of High Biomass Rice (Oryza sativa L.) to Various Abiotic Stresses Copyright 2010 Aditi...

  15. Potential Paddy Rice Yields for Rainfed and Irrigated Agriculture in China and Korea

    Microsoft Academic Search

    W. H. Terjung; J. T. Hayes; H. Y. Ji; P. E. Todhunter; P. A. ORourke

    1985-01-01

    YIELD, a water-balance and crop-yield model that calculates production and water consumption variables for a variety of major crops, was applied specifically for wetland rice to China and Korea in order to estimate the region's potential and actual yields for irrigated and rainfed rice production. A network of 241 stations provided the climatic data averaged over approximately a 25-year period.

  16. Phytoremediation of arsenic contaminated paddy soils with Pteris vittata markedly reduces arsenic uptake by rice

    Microsoft Academic Search

    Wen-Ling Ye; M. Asaduzzaman Khan; Steve P. McGrath; Fang-Jie Zhao

    2011-01-01

    Arsenic (As) accumulation in food crops such as rice is of major concern. To investigate whether phytoremediation can reduce As uptake by rice, the As hyperaccumulator Pteris vittata was grown in five contaminated paddy soils in a pot experiment. Over a 9-month period P. vittata removed 3.5–11.4% of the total soil As, and decreased phosphate-extractable As and soil pore water As

  17. The Effect of Planting Strategies, Imazethapyr Rates, and Application Timings on CLEARFIELD® Hybrid Rice Injury

    E-print Network

    Turner, Aaron Lyles

    2012-02-14

    THE EFFECT OF PLANTING STRATEGIES, IMAZETHAPYR RATES, AND APPLICATION TIMINGS ON CLEARFIELD? HYBRID RICE INJURY A Thesis by AARON LYLES TURNER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 2011 Major Subject: Agronomy THE EFFECT OF PLANTING STRATEGIES, IMAZETHAPYR RATES, AND APPLICATION TIMINGS ON CLEARFIELD? HYBRID RICE INJURY A Thesis by AARON LYLES TURNER Submitted to the Office...

  18. Priming of field-sown rice seed enhances germination, seedling establishment, allometry and yield

    Microsoft Academic Search

    Muhammad Farooq; Shahzad M. A. Barsa; Abdul Wahid

    2006-01-01

    Poor seedling establishment is a major deterrent in adopting direct seeding of rice. Seed priming to obtain better crop stand could be an attractive approach. The objective of this study was to determine the effectiveness of seed priming strategies on the improved agronomic characters of direct-sown rice. Seed priming strategies were: hydropriming for 48 h, osmohardening with KCl or CaCl2 for

  19. Seed Priming Effects on Germination, Growth and Yield of Dry Direct-Seeded Rice

    Microsoft Academic Search

    G. Mahajan; R. S. Sarlach; S. Japinder; M. S. Gill

    2011-01-01

    Insufficient seedling stand establishment is one of the major obstacles for achieving potential yield of dry direct-seeded rice (Oryza sativa L.). In the present study, seed priming technique was explored for improving germination and crop performance of dry direct-seeded rice. Seed-priming treatments used during the investigation included untreated control, hydro-priming, water hardening, and osmo-hardening with KCl. Priming reduced mean germination

  20. Rice Young Alumni 6100 Main Street MS 520

    E-print Network

    Palem, Krishna V.

    Rice Young Alumni 6100 Main Street MS 520 Houston, Texas 77005 Phone: 713-348-4057 alumni.rice.edu Rice Houston Young Alumni on Facebook Rice Young Alumni Handbook How to Access Your Rice Young Alumni Resources and Programs Step 1 Create an alumni profile on alumni.rice.edu Step 2 Join your favorite ARA

  1. Storage stability of flour-blasted brown rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brown rice was blasted with rice flour rather than sand in a sand blaster to make microscopic nicks and cuts so that water can easily penetrate into the brown rice endosperm and cook the rice in a shorter time. The flour-blasted American Basmati brown rice, long grain brown rice, and parboiled long...

  2. 2nd International Workshop on Software Ecosystems (EcoSys)

    Microsoft Academic Search

    P. R. J. Campbell; Faheem Ahmed; Jan Bosch; Slinger Jansen

    2010-01-01

    The concept of software ecosystems encourages external developers to use an organizations' software platform and contribute in product development. This establishes a community that further accelerates the sharing of knowledge, content, issues, expertise, and skills. A number of major international software development organizations including Amazon, Nokia, and Apple are pioneering the development of software ecosystems and the area is currently

  3. Ecosystem nitrogen retention and flushing across a soil texture gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most ecosystems retain a majority of reactive N inputs, transforming reactive mineral N into relatively nonreactive stable organic N. Mechanistic explanations for these observations focus on C-dependent processes, and in particular wide C:N ratios. However, in some ecosystems C-dependent mechanism...

  4. Assessing the functional implications of soil biodiversity in ecosystems

    Microsoft Academic Search

    Thomas Hefin Jones; Mark Alexander Bradford

    2001-01-01

    Soil communities are among the most species-rich components of terrestrial ecosystems. A major challenge for soil ecologists is to formulate feasible research strategies that will preserve and capitalize on the biodiversity resources of the soil. This article considers the role of soil organism diversity by concentrating on: (i) the relationship between soil biodiversity and ecosystem function; (ii) what issues need

  5. Mycorrhizal fungi mediation of terrestrial ecosystem responses to global change

    E-print Network

    Mohan, Jacqueline E.

    Mycorrhizal fungi mediation of terrestrial ecosystem responses to global change: mini a b s t r a c t Mycorrhizal fungi are responsible for most nutrient uptake by the majority of land that explicitly address the role of mycorrhizal influence on ecosystem responses such as biogeochemical fluxes

  6. Ecosystem Consequences of Biodiversity Loss: The Evolution of a Paradigm

    Microsoft Academic Search

    Shahid Naeem

    2002-01-01

    The ecosystem consequences of dramatic declines or changes in biodiversity have spurred considerable research and tremendous debate that has rekindled most of the major conflicts in ecology, creating a sense of dejavu. These conflicts include whether ecosystem or community ecology provides better insights into the workings of nature, the relative importance of biotic vs. abiotic factors in governing community composition

  7. Thermomechanical Transitions of Rice Kernels

    Microsoft Academic Search

    Zhenhua Sun; Wade Yang; Terry Siebenmorgen; Annemieke Stelwagen; Auke Cnossen

    2002-01-01

    Cereal Chem. 79(3):349-353 Thermomechanical analysis (TMA) and differential scanning calori- metry (DSC) were used to investigate the thermal transitions of long-grain rice kernels. Three distinct thermomechanical transitions were identified as rice kernels were heated from 0 to 200°C. The identified transitions were a low temperature transition with onset at ?45°C, an intermediate tem- perature transition at ?80°C, and a high

  8. Development of a novel transgenic rice with hypocholesterolemic activity via high-level accumulation of the ?' subunit of soybean ?-conglycinin.

    PubMed

    Cabanos, Cerrone; Kato, Naoki; Amari, Yoshiki; Fujiwara, Keigo; Ohno, Tomoki; Shimizu, Kousuke; Goto, Tsuyoshi; Shimada, Masaya; Kuroda, Masaharu; Masuda, Taro; Takaiwa, Fumio; Utsumi, Shigeru; Nagaoka, Satoshi; Maruyama, Nobuyuki

    2014-08-01

    Soybean 7S globulin, known as ?-conglycinin, has been shown to regulate human plasma cholesterol and triglyceride levels. Furthermore, the ?' subunit of ?-conglycinin has specifically been shown to possess low-density lipoprotein (LDL)-cholesterol-lowering activity. Therefore, accumulation of the ?' subunit of ?-conglycinin in rice seeds could lead to the production of new functional rice that could promote human health. Herein, we used the low-glutelin rice mutant 'Koshihikari' (var. a123) and suppressed its glutelins and prolamins, the major seed storage proteins of rice, by RNA interference. The accumulation levels of the ?' subunit in the lines with suppressed glutelin and prolamin levels were >20 mg in 1 g of rice seeds, which is considerably higher than those in previous studies. Oral administration of the transgenic rice containing the ?' subunit exhibited a hypocholesterolemic activity in rats; the serum total cholesterol and LDL cholesterol levels were significantly reduced when compared to those of the control rice (var. a123). The cholesterol-lowering action by transgenic rice accumulating the ?' subunit induces a significant increase in fecal bile acid excretion and a tendency to increase in fecal cholesterol excretion. This is the first report that transgenic rice exhibits a hypocholesterolemic activity in rats in vivo by using the ?-conglycinin ?' subunit. PMID:24676962

  9. Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches

    PubMed Central

    Kumar, Arvind; Dixit, Shalabh; Ram, T.; Yadaw, R. B.; Mishra, K. K.; Mandal, N. P.

    2014-01-01

    The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1, qDTY 2.2, qDTY 3.1, qDTY 3.2, qDTY 6.1, and qDTY 12.1) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding. PMID:25205576

  10. Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches.

    PubMed

    Kumar, Arvind; Dixit, Shalabh; Ram, T; Yadaw, R B; Mishra, K K; Mandal, N P

    2014-11-01

    The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1 , qDTY 2.2 , qDTY 3.1 , qDTY 3.2 , qDTY 6.1 , and qDTY 12.1 ) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding. PMID:25205576

  11. Where Will Ecosystems Go?

    SciTech Connect

    Janetos, Anthony C.

    2008-09-29

    Climate-induced changes in ecosystems have been both modeled and documented extensively over the past 15-20 years. Those changes occur in the context of many other stresses and interacting factors, but it is clear that many, if not most, ecosystems are sensitive to changing climate.

  12. Ecosystems, Teacher's Guide.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Science Curriculum Improvement Study.

    The Science Curriculum Improvement Study has developed this teacher's guide to "Ecosystems," the sixth part of a six unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems. They make use of scientific and…

  13. Earth on Edge : Ecosystems

    NSDL National Science Digital Library

    Gregory Mock

    2000-01-01

    This site provides information about the six ecosystems on which life on Earth most heavily depends: agricultural, forest, freshwater, grassland, coastal, and urban. It is part of a Public Broadcasting System (PBS) project, which includes a discussion guide. Ecosystems are described as communities of interacting organisms and the physical environment in which they live. The goods and services that ecosystems provide are said to form the foundation of human economies. Ecosystems purify air and water, help to control climate, and produce valuable soil-services. Site users may access a discussion guide to accompany the broadcast of the video/television program, which can be used in colleges, secondary schools, and in community groups. Case studies are taken from the companion book, World Resources 2000-2001: Ecosystems and People: The Fraying Web of Life, and from Pilot Analysis of Global Ecosystems: Agroecosystems (World Resources Institute). This online text includes profiles, case studies, and ecosystem assessments with references to ecosystems around the world. A list of additional resources includes links to environmental organizations, books, and periodicals.

  14. What Is Ecosystem Management?

    Microsoft Academic Search

    R. Edward Grumbine

    1994-01-01

    The evolving concept of ecosystem management is the focus of much current debate. To clarify discussion and provide a frammork for implementatiotq I trace the histor- ical development of ecosystem management, provide a working definitioq and summarize dominant themes taken from an extensive literature reuiew. The general goal of maintaining ecological integ?Yty is discussed along with five specific goals: maintaining

  15. Accessibility and Product Ecosystems

    Microsoft Academic Search

    Jim Tobias

    2007-01-01

    Products, including assistive and accessible technologies, do not exist in isolation. They are all part of rich product ecosystems; they inhabit specific niches of economics, functionality, and technology, and they interact with other products. The concept of product ecosystem goes beyond technological interoperability. For accessibility to advance, we must understand more about the interactions among products. This article sketches an

  16. Environmental Biology - Ecosystems

    NSDL National Science Digital Library

    Dave McShaffrey

    This resource explains how energy and pollutants move through an ecosystem, how ecosystems are balanced and how they may be affected by human activities. Concepts described include the roles of organisms, food chains and food webs, pyramids of biomass, biological magnification, and biogeochemical cycles such as water, carbon, nitrogen, and phosphorous cycles.

  17. Rice University: Colvin Group

    NSDL National Science Digital Library

    The Colvin Group at Rice University deals with the control and understanding of material properties on nanometer length scales. Some members of the group work to "develop new chemical approaches to forming uniform nanocrystals, and highly ordered porous solids" while "others focus on using these materials as tools for answering fundamental questions about nature, such as the characteristic length scales in glasses and liquids." Researchers can learn about the numerous projects undertaken by the group including understanding the superprism phenomena, the preparation of perfect nanocrystals of metal oxides, and the synthesis of quartz particles in the sub-micron to nanoscale size regime. Students and educators can find helpful tutorials describing the nanoscience field of study. The website also provides many of the group's published papers.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled...for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled... In long grain rice (percent) In medium or short grain rice (percent)...

  20. SSR marker analysis of atypical U.S red rice phenotypes: indications of prior gene flow in rice fields?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is a troublesome weed problem in rice fields of the southern U.S. Outcrossing between rice and red rice occurs at low rates, resulting in a broad array of plant types. SSR markers were used to evaluate the genetic backgrounds of atypical red rice types obtained from rice farms in comparis...

  1. Outcrossing potential between U.S. red rice (Oryza sativa) and Chinese indica rice (Oryza sativa) lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice in southern U.S. rice fields remains a widespread, economically challenging problem despite nearly a decade of rice production systems that include true-breeding rice cultivars and indica-derived hybrid rice with resistance to imazethapyr. Both of these herbicide-resistant rice systems hav...

  2. Pullulanase from rice endosperm.

    PubMed

    Yamasaki, Yoshiki; Nakashima, Susumu; Konno, Haruyoshi

    2008-01-01

    Pullulanase (EC 3.2.1.41) in non-germinating seeds was compared with that in germinating seeds. Moreover, pullulanase from the endosperm of rice (Oryza sativa L., cv. Hinohikari) seeds was isolated and its properties investigated. The pI value of pullulanase from seeds after 8 days of germination was almost equal to that from non-germinating seeds, which shows that these two enzymes are the same protein. Therefore, the same pullulanase may play roles in both starch synthesis during ripening and starch degradation during germination in rice seeds. The enzyme was isolated by a procedure that included ammonium sulfate fractionation, DEAE-cellulofine column chromatography, preparative isoelectric focusing, and preparative disc gel electrophoresis. The enzyme was homogeneous by SDS/PAGE. The molecular weight of the enzyme was estimated to be 100 000 based on its mobility on SDS/PAGE and 105 000 based on gel filtration with TSKgel super SW 3000, which showed that it was composed of a single unit. The isoelectric point of the enzyme was 4.7. The enzyme was strongly inhibited by beta-cyclodextrin. The enzyme was not activated by thiol reagents such as dithiothreitol, 2-mercaptoethanol or glutathione. The enzyme most preferably hydrolyzed pullulan and liberated only maltotriose. The pullulan hydrolysis was strongly inhibited by the substrate at a concentration higher than 0.1%. The degree of inhibition increased with an increase in the concentration of pullulan. However, the enzyme hydrolyzed amylopectin, soluble starch and beta-limit dextrin more rapidly as their concentrations increased. The enzyme exhibited alpha-glucosyltransfer activity and produced an alpha-1,6-linked compound of two maltotriose molecules from pullulan. PMID:18787715

  3. Ecosystem Viable Yields

    E-print Network

    De Lara, Michel; Oliveros-Ramos, Ricardo; Tam, Jorge

    2011-01-01

    The World Summit on Sustainable Development (Johannesburg, 2002) encouraged the application of the ecosystem approach by 2010. However, at the same Summit, the signatory States undertook to restore and exploit their stocks at maximum sustainable yield (MSY), a concept and practice without ecosystemic dimension, since MSY is computed species by species, on the basis of a monospecific model. Acknowledging this gap, we propose a definition of "ecosystem viable yields" (EVY) as yields compatible i) with biological viability levels for all time and ii) with an ecosystem dynamics. To the difference of MSY, this notion is not based on equilibrium, but on viability theory, which offers advantages for robustness. For a generic class of multispecies models with harvesting, we provide explicit expressions for the EVY. We apply our approach to the anchovy--hake couple in the Peruvian upwelling ecosystem between the years 1971 and 1981.

  4. SEVEN PILLARS OF ECOSYSTEM MANAGEMENT

    EPA Science Inventory

    Ecosystem management is widely proposed in the popular and professional literature as the modern and preferred way of managing natural resources and ecosystems. Advocates glowingly describe ecosystem management as an approach that will protect the environment, maintain healthy ec...

  5. Ecosystem Restoration through Interdisciplinary Exchange

    E-print Network

    Sachs, Frederick

    Ecosystem Restoration through Interdisciplinary Exchange David M. Blersch dblersch Shade of Blue and You 21 September 2010 #12;National Science Foundation Ecosystem Restoration through;National Science Foundation Ecosystem Restoration through Interdisciplinary Exchange UB's ERIE Program www

  6. Identification of aluminium-regulated genes by cDNA AFLP in rice (Oryza sativa L.): aluminium-regulated genes for the metabolism of cell wall components

    Microsoft Academic Search

    Chuanzao Mao; Keke Yi; Ling Yang; Bingsong Zheng; Yunrong Wu; Feiyan Liu; Ping Wu

    2004-01-01

    Aluminium (Al) toxicity is the major factor limiting crop productivity in acid soils. To investigate the molecular mechanisms of Al toxicity and Al tolerance of rice, cDNA-amplified fragment length polymorph- ism (cDNA-AFLP) was used for identifying Al-regu- lated genes in roots of an Al-tolerant tropical upland rice, Azucena, and an Al-sensitive lowland rice, IR1552. Nineteen function-known genes were found among

  7. Identification and analysis of QTLs controlling cold tolerance at the reproductive stage and validation of effective QTLs in cold-tolerant genotypes of rice ( Oryza sativa L.)

    Microsoft Academic Search

    J. P. Suh; J. U. Jeung; J. I. Lee; Y. H. Choi; J. D. Yea; P. S. Virk; D. J. Mackill; K. K. Jena

    2010-01-01

    Low temperature or cold stress is one of the major constraints of rice production and productivity in temperate rice-growing\\u000a countries and high-altitude areas in the tropics. Even though low temperature affects the rice plant in all stages of growth,\\u000a the percent seed set is damaged severely by cold and this reduces the yield potential of cultivars significantly. In this\\u000a study,

  8. Role of fungi in marine ecosystems

    Microsoft Academic Search

    Kevin D. Hyde; E. B. Gareth Jones; Eduardo Leaño; Stephen B. Pointing; Asha D. Poonyth; Lilian L. P. Vrijmoed

    1998-01-01

    Marine fungi are an ecological rather than a taxonomic group and comprise an estimated 1500 species, excluding those that form lichens. They occur in most marine habitats and generally have a pantropical or pantemperate distribution. Marine fungi are major decomposers of woody and herbaceous substrates in marine ecosystems. Their importance lies in their ability to aggressively degrade lignocellulose. They may

  9. Processing Conditions, Rice Properties, Health and Environment

    PubMed Central

    Roy, Poritosh; Orikasa, Takahiro; Okadome, Hiroshi; Nakamura, Nobutaka; Shiina, Takeo

    2011-01-01

    Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR), germinated brown rice (GBR) and partially-milled rice (PMR) contains more health beneficial food components compared to the well milled rice (WMR). Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR) seems to be relatively prone to arsenic contamination compared to that of untreated rice, if contaminated water is used for parboiling and cooking. A change in consumption patterns from PBR to untreated rice (non-parboiled), and WMR to PMR or BR may conserve about 43–54 million tons of rice and reduce the risk from arsenic contamination in the arsenic prone area. This study also reveals that a change in rice consumption patterns not only supply more food components but also reduces environmental loads. A switch in production and consumption patterns would improve food security where food grains are scarce, and provide more health beneficial food components, may prevent some diseases and ease the burden on the Earth. However, motivation and awareness of the environment and health, and even a nominal incentive may require for a method switching which may help in building a sustainable society. PMID:21776212

  10. Natural rice rhizospheric microbes suppress rice blast infections

    PubMed Central

    2014-01-01

    Background The natural interactions between plant roots and their rhizospheric microbiome are vital to plant fitness, modulating both growth promotion and disease suppression. In rice (Oryza sativa), a globally important food crop, as much as 30% of yields are lost due to blast disease caused by fungal pathogen Magnaporthe oryzae. Capitalizing on the abilities of naturally occurring rice soil bacteria to reduce M. oryzae infections could provide a sustainable solution to reduce the amount of crops lost to blast disease. Results Naturally occurring root-associated rhizospheric bacteria were isolated from California field grown rice plants (M-104), eleven of which were taxonomically identified by16S rRNA gene sequencing and fatty acid methyl ester (FAME) analysis. Bacterial isolates were tested for biocontrol activity against the devastating foliar rice fungal pathogen, M. oryzae pathovar 70–15. In vitro, a Pseudomonas isolate, EA105, displayed antibiosis through reducing appressoria formation by nearly 90% as well as directly inhibiting fungal growth by 76%. Although hydrogen cyanide (HCN) is a volatile commonly produced by biocontrol pseudomonads, the activity of EA105 seems to be independent of its HCN production. During in planta experiments, EA105 reduced the number of blast lesions formed by 33% and Pantoea agglomerans isolate, EA106 by 46%. Our data also show both EA105 and EA106 trigger jasmonic acid (JA) and ethylene (ET) dependent induced systemic resistance (ISR) response in rice. Conclusions Out of 11 bacteria isolated from rice soil, pseudomonad EA105 most effectively inhibited the growth and appressoria formation of M. oryzae through a mechanism that is independent of cyanide production. In addition to direct antagonism, EA105 also appears to trigger ISR in rice plants through a mechanism that is dependent on JA and ET signaling, ultimately resulting in fewer blast lesions. The application of native bacteria as biocontrol agents in combination with current disease protection strategies could aid in global food security. PMID:24884531

  11. Storm in a rice bowl: Rice reform and poverty in Vietnam in the 1990s

    Microsoft Academic Search

    Yoko Niimi; Puja Vasudeva-Dutta; L. Alan Winters

    2004-01-01

    This paper analyses the poverty impact of Vietnam’s reforms, especially with reference to the rice economy, during the 1990s. It reviews trade and institutional reforms that directly impinged on the rice sector, and the trends in rice production, consumption and prices throughout the 1990s. We then analyse the impact of rice production on poverty dynamics by estimating a multinomial logit

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Major Andre

    ERIC Educational Resources Information Center

    Henisch, B. A.; Henisch, H. K.

    1976-01-01

    If most Revolutionary era people seem two-dimensional their lives simpler to understand than ours, it may be only that history, with the benefit of hindsight, clarifies. Examines a profile of Major John Andre, the British liaison officer in Benedict Arnold's plan to surrender West Point, as both hero and villain to show the complexity of early…

  14. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria

    PubMed Central

    Okubo, Takashi; Liu, Dongyan; Tsurumaru, Hirohito; Ikeda, Seishi; Asakawa, Susumu; Tokida, Takeshi; Tago, Kanako; Hayatsu, Masahito; Aoki, Naohiro; Ishimaru, Ken; Ujiie, Kazuhiro; Usui, Yasuhiro; Nakamura, Hirofumi; Sakai, Hidemitsu; Hayashi, Kentaro; Hasegawa, Toshihiro; Minamisawa, Kiwamu

    2015-01-01

    A number of studies have shown that elevated atmospheric CO2 ([CO2]) affects rice yields and grain quality. However, the responses of root-associated bacteria to [CO2] elevation have not been characterized in a large-scale field study. We conducted a free-air CO2 enrichment (FACE) experiment (ambient + 200 ?mol.mol?1) using three rice cultivars (Akita 63, Takanari, and Koshihikari) and two experimental lines of Koshihikari [chromosome segment substitution and near-isogenic lines (NILs)] to determine the effects of [CO2] elevation on the community structure of rice root-associated bacteria. Microbial DNA was extracted from rice roots at the panicle formation stage and analyzed by pyrosequencing the bacterial 16S rRNA gene to characterize the members of the bacterial community. Principal coordinate analysis of a weighted UniFrac distance matrix revealed that the community structure was clearly affected by elevated [CO2]. The predominant community members at class level were Alpha-, Beta-, and Gamma-proteobacteria in the control (ambient) and FACE plots. The relative abundance of Methylocystaceae, the major methane-oxidizing bacteria in rice roots, tended to decrease with increasing [CO2] levels. Quantitative PCR revealed a decreased copy number of the methane monooxygenase (pmoA) gene and increased methyl coenzyme M reductase (mcrA) in elevated [CO2]. These results suggest elevated [CO2] suppresses methane oxidation and promotes methanogenesis in rice roots; this process affects the carbon cycle in rice paddy fields.

  15. Cultural perspectives and current consumption changes of cooked rice in Korean diet

    PubMed Central

    2007-01-01

    Cooked rice is a staple food for Koreans which provides more than 60% of daily required energy. In 1960's, Koreans ate 600 g-800 g of cooked rice per meal and the energy obtained from cooked rice was almost more than 80% of the daily intake of energy. However, as the economy of Korea improved, the major industry has been shifted from agriculture to various manufacturing industries and the export of those products has been increased thus increasing the national income but decreasing the farming population and thus rice consumption have been decreased. It has been said that the decreased rice consumption is caused solely by decreased farming population but it can also be said that the decreased farming population is caused by decreased rice consumption. As the national income increases, the type of foods people consume have become diversified. Various processed foods such as convenience food or ready-to-eat food have been widespread, which are mostly made of wheat flour rather than rice. PMID:20535379

  16. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria.

    PubMed

    Okubo, Takashi; Liu, Dongyan; Tsurumaru, Hirohito; Ikeda, Seishi; Asakawa, Susumu; Tokida, Takeshi; Tago, Kanako; Hayatsu, Masahito; Aoki, Naohiro; Ishimaru, Ken; Ujiie, Kazuhiro; Usui, Yasuhiro; Nakamura, Hirofumi; Sakai, Hidemitsu; Hayashi, Kentaro; Hasegawa, Toshihiro; Minamisawa, Kiwamu

    2015-01-01

    A number of studies have shown that elevated atmospheric CO2 ([CO2]) affects rice yields and grain quality. However, the responses of root-associated bacteria to [CO2] elevation have not been characterized in a large-scale field study. We conducted a free-air CO2 enrichment (FACE) experiment (ambient + 200 ?mol.mol(-1)) using three rice cultivars (Akita 63, Takanari, and Koshihikari) and two experimental lines of Koshihikari [chromosome segment substitution and near-isogenic lines (NILs)] to determine the effects of [CO2] elevation on the community structure of rice root-associated bacteria. Microbial DNA was extracted from rice roots at the panicle formation stage and analyzed by pyrosequencing the bacterial 16S rRNA gene to characterize the members of the bacterial community. Principal coordinate analysis of a weighted UniFrac distance matrix revealed that the community structure was clearly affected by elevated [CO2]. The predominant community members at class level were Alpha-, Beta-, and Gamma-proteobacteria in the control (ambient) and FACE plots. The relative abundance of Methylocystaceae, the major methane-oxidizing bacteria in rice roots, tended to decrease with increasing [CO2] levels. Quantitative PCR revealed a decreased copy number of the methane monooxygenase (pmoA) gene and increased methyl coenzyme M reductase (mcrA) in elevated [CO2]. These results suggest elevated [CO2] suppresses methane oxidation and promotes methanogenesis in rice roots; this process affects the carbon cycle in rice paddy fields. PMID:25750640

  17. Global value of GM rice: a review of expected agronomic and consumer benefits.

    PubMed

    Demont, Matty; Stein, Alexander J

    2013-06-25

    Unlike the other major crops, no genetically modified (GM) varieties of rice have been commercialized at a large scale. Within the next 2-3 years new transgenic rice varieties could be ready for regulatory approval and subsequent commercialization, though. Given the importance of rice as staple crop for many of the world's poorest people, this will have implications for the alleviation of poverty, hunger and malnutrition. Thus, policy-makers need to be aware of the potential benefits of GM rice. We provide an overview of the literature and discuss the evidence on expected agronomic and consumer benefits of genetically engineered rice. We find that while GM rice with improved agronomic traits could deliver benefits similar to already commercialized biotechnology crops, expected benefits of consumer traits could be higher by an order of magnitude. By aggregating the expected annual benefits, we estimate the global value of GM rice to be US$64 billion per year. This is only an indicative value, as more GM varieties will become available in future. Nevertheless, such a figure can help guide policy-makers when deciding on the approval or funding of biotechnology crops and it may also raise awareness among consumers about what is at stake for their societies. PMID:23628812

  18. The role of the rice aquaporin Lsi1 in arsenite efflux from roots.

    PubMed

    Zhao, Fang-Jie; Ago, Yukiko; Mitani, Namiki; Li, Ren-Ying; Su, Yu-Hong; Yamaji, Naoki; McGrath, Steve P; Ma, Jian Feng

    2010-04-01

    *When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. *Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. *Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 mum arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. *We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters. PMID:20163552

  19. ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes

    E-print Network

    Iliffe, Thomas M.

    . However, spatial distributions of microbial biomass and species present within these major clades were rRNA clone libraries Á Microbial ecology Á Bahamas Introduction Anchialine caves characteristicallyANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes: initial discoveries from

  20. Broader perspective on ecosystem sustainability: Consequences for decision making

    PubMed Central

    Sidle, Roy C.; Benson, William H.; Carriger, John F.; Kamai, Toshitaka

    2013-01-01

    Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making. PMID:23686583

  1. Broader perspective on ecosystem sustainability: consequences for decision making.

    PubMed

    Sidle, Roy C; Benson, William H; Carriger, John F; Kamai, Toshitaka

    2013-06-01

    Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making. PMID:23686583

  2. Texas Rice, Volume VI, Number 7

    E-print Network

    Providing useful and timely information to Texas rice growers, so they may increase productivity and profitability on their farms. Diatomaceous Earth Plus Methoprene for Control of the Lesser Grain Borer, Rhyzopertha Dominica, in Rough Rice The lesser...

  3. RICE UNIVERSITY Speeding Up Mobile Browsers

    E-print Network

    Zhong, Lin

    RICE UNIVERSITY Speeding Up Mobile Browsers without Infrastructure Support by Zhen Wang A THESIS, Professor Lin Zhong, for his guidance and encour- agement during my study and research at Rice University

  4. Coral Reef Ecosystems: Interdependence

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2006-11-01

    This Science Object is the third of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the interdependent relationships between species in the coral reef ecosystem. All populations in the reef ecosystem are a part of and depend on a global food web (a connected set of food chains) through which energy flows in one direction, from the sun into organism and eventually dissipating into the environment as heat. This food web includes ocean plants, the animals that feed on them, and the animals that feed on those animals. Energy is transferred between organisms and their environment along the way. Energy concentration diminishes at each step. The cycles of life continue indefinitely because organisms decompose after death and return food materials to the environment. Learning Outcomes:? Identify and label key components of food chains and food webs in a coral reef ecosystem.? Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).? Recognize the direction that energy travels through food chains and food webs.? Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.? Describe the primary ecological succession events within a typical coral reef ecosystem.

  5. Rice Facts -Students : Rice University http://professor.rice.edu/professor/Students4.asp[9/13/2011 11:10:41 AM

    E-print Network

    Richards-Kortum, Rebecca

    Rice Facts - Students : Rice University http://professor.rice.edu/professor/Students4.asp[9/13/2011 11:10:41 AM] Parents Undergraduates Grad Students Faculty & Researchers Staff Alumni Rice Facts - Students Faculty and Researchers > Office of Institutional Research > Rice Facts - Students Home

  6. Effect of hydrothermal treatment of rice flour on various rice noodles quality

    Microsoft Academic Search

    Supawadee Cham; Prisana Suwannaporn

    2010-01-01

    The rice noodle industry in Thailand is facing problems regarding rice flour quality. This research aims to study the effects of hydrothermally modified rice flour on improving rice noodle quality. High-amylose rice flour (Chai Nat 1 variety) was modified using heat–moisture treatment (HMT) and annealing (ANN). Response surface methodology (RSM) with face-centered central composite design (FCCD) was applied to optimize

  7. Methane mitigation in flooded Louisiana rice fields

    Microsoft Academic Search

    C. W. Lindau; P. K. Bollich; R. D. DeLaune; A. R. Mosier; K. F. Bronson

    1993-01-01

    A field experiment was conducted to determine whether selected nitrification inhibitors (encapsulated calcium carbide and dicyandiamide) and SOinf4sup-2-containing compounds [(NH4)2SO4 and Na2SO4] had mitigating effects on CH4 emissions from flooded rice. Microplots were established within a rice bay drill-seeded with the Texmont rice cultivar and CH4 fluxes were measured over the main rice cropping season. Methane emissions over the 77-day

  8. Texas Rice, Volume V, Number 8

    E-print Network

    in commercial U.S. rice cultivars, but Yan has identified 26 indica and japonica rice lines that are resistant. Breeders at the University of Arkansas and Louisiana State University have incorporated some of these germplasm lines into their programs... to improve straighthead resistance in rice breeding in the southern United States. Stuttgart researchers are also addressing undesirable amylose content levels in indica rice. Amylose content is the characteristic used to describe the difference between dry...

  9. Tecnologa para todos Sistema Inalmbrico de Rice

    E-print Network

    Tecnología para todos Sistema Inalámbrico de Rice Andrea Trevino Rice University http://www.techforall.org/tfa_wireless.html http://tfa.rice.edu #12;Por qué en Pecan Park? La Misión de TFA: Proporcionar conocimientos a la comunidad. El propósito de Rice: Usar este programa para explorar la siguiente generación del sistema

  10. Kinetics of pyrolysis of rice husk

    Microsoft Academic Search

    Atul Sharma; T. Rajeswara Rao

    1999-01-01

    The pyrolysis of rice husk in both grain and powder form was investigated to determine the kinetic parameters. Experiments under non-isothermal conditions were carried out for rice husk grain and powder samples in nitrogen, and for rice husk grain samples in carbon dioxide at heating rates of 5, 10, 25, 50 and 100°C\\/min. Experiments were also carried out with rice

  11. INTRODUCTION Coral reef ecosystems are among the most biologically diverse and

    E-print Network

    Paris-Sud XI, Université de

    1 INTRODUCTION Coral reef ecosystems are among the most biologically diverse and complex marine ecosystems worldwide. In addition to their biological and ecological importance, coral reefs support major to as zooxanthellae (Lesser, 2004). Because of global climate change and anthropogenic pressure, coral reef ecosystems

  12. Factors controlling the temporal variability of ecosystem respiration and its carbon isotope composition

    Microsoft Academic Search

    J. Fassbinder; T. J. Griffis; J. M. Baker; M. Erickson; K. Billmark; J. Smith

    2009-01-01

    Ecosystem respiration (FR ) is the major pathway for carbon loss from terrestrial ecosystems. Stable carbon isotope analyses have been used to improve our understanding of the processes controlling ecosystem respiration. In particular, 13CO2 has been used to partition the autotrophic (Fa) and heterotrophic (Fh) contributions to FR. Further, there has been some concern in the literature regarding the temporal

  13. Ecological Engineering 26 (2006) 626 Scientific requirements for ecosystem-based management

    E-print Network

    Ecological Engineering 26 (2006) 6­26 Scientific requirements for ecosystem-based management March 2005; accepted 26 September 2005 Abstract Ecosystem-based management requires integration underway or in planning to restore and manage two major coastal ecosystems, the Chesapeake Bay (Chesapeake

  14. Modeling nighttime ecosystem respiration from measured CO2 concentration and air temperature profiles using inverse methods

    Microsoft Academic Search

    Jehn-Yih Juang; Gabriel G. Katul; Mario B. S. Siqueira; Paul C. Stoy; Sari Palmroth; Heather R. McCarthy; Hyun-Seok Kim; Ram Oren

    2006-01-01

    A major challenge for quantifying ecosystem carbon budgets from micrometeorological methods remains nighttime ecosystem respiration. An earlier study utilized a constrained source optimization (CSO) method using inverse Lagrangian dispersion theory to infer the two components of ecosystem respiration (aboveground and forest floor) from measured mean CO2 concentration profiles within the canopy. This method required measurements of within-canopy mean velocity statistics

  15. Rice consumption and risk of cardiovascular disease: results from a pooled analysis of 3 U.S. cohorts1234

    PubMed Central

    Muraki, Isao; Wu, Hongyu; Imamura, Fumiaki; Laden, Francine; Rimm, Eric B; Hu, Frank B; Willett, Walter C; Sun, Qi

    2015-01-01

    Background: Health concerns have been raised about rice consumption, which may significantly contribute to arsenic exposure. However, little is known regarding whether habitual rice consumption is associated with cardiovascular disease (CVD) risk. Objective: We examined prospectively the association of white rice and brown rice consumption with CVD risk. Design: We followed a total of 207,556 women and men [73,228 women from the Nurses’ Health Study (1984–2010), 92,158 women from the Nurses’ Health Study II (1991–2011), and 42,170 men from the Health Professionals Follow-Up Study (1986–2010)] who were free of CVD and cancer at baseline. Validated semiquantitative food-frequency questionnaires were used to assess consumption of white rice, brown rice, and other food items. Fatal and nonfatal CVD (coronary artery disease and stroke) was confirmed by medical records or self-reports. Results: During 4,393,130 person-years of follow-up, 12,391 cases of CVD were identified. After adjustment for major CVD risk factors, including demographics, lifestyle, and other dietary intakes, rice consumption was not associated with CVD risk. The multivariable-adjuted HR of developing CVD comparing ?5 servings/wk with <1 serving/wk was 0.98 (95% CI: 0.84, 1.14) for white rice, 1.01 (0.79, 1.28) for brown rice, and 0.99 (0.90, 1.08) for total rice. To minimize the potential impact of racial difference in rice consumption, we restricted the analyses to whites only and obtained similar results: the HRs of CVD for ?5 servings/wk compared with <1 serving/wk were 1.04 (95% CI: 0.88, 1.22) for white rice and 1.01 (0.78, 1.31) for brown rice. Conclusions: Greater habitual consumption of white rice or brown rice is not associated with CVD risk. These findings suggest that rice consumption may not pose a significant CVD risk among the U.S. population when consumed at current amounts. More prospective studies are needed to explore these associations in other populations. PMID:25527760

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

    PubMed

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

    2013-12-01

    The Eastern Himalayan region of Northeast (NE) India is home to a large number of indigenous rice varieties, which may serve as a valuable genetic resource for future crop improvement to meet the ever-increasing demand for food production. However, these varieties are rapidly being lost due to changes in land-use and agricultural practices, which favor agronomically improved varieties. A detailed understanding of the genetic structure and diversity of indigenous rice varieties is crucial for efficient utilization of rice genetic resources and for developing suitable conservation strategies. To explore the genetic structure and diversity of rice varieties in NE India, we genotyped 300 individuals of 24 indigenous rice varieties representing sali, boro, jum and glutinous types, 5 agronomically improved varieties, and one wild rice species (O. rufipogon) using seven SSR markers. A total of 85 alleles and a very high level of gene diversity (0.776) were detected among the indigenous rice varieties of the region. Considerable level of genetic variation was found within indigenous varieties whereas improved varieties were monoporphic across all loci. The comparison of genetic diversity among different types of rice revealed that sali type possessed the highest gene diversity (0.747) followed by jum (0.627), glutinous (0.602) and boro (0.596) types of indigenous rice varieties, while the lowest diversity was detected in agronomically improved varieties (0.459). The AMOVA results showed that 66% of the variation was distributed among varieties indicating a very high level of genetic differentiation in rice varieties in the region. Two major genetically defined clusters corresponding to indica and japonica groups were detected in rice varieties of the region. Overall, traditionally cultivated indigenous rice varieties in NE India showed high levels of genetic diversity comparable to levels of genetic diversity reported from wild rice populations in various parts of the world. The efforts for conservation of rice germplasm in NE India should consider saving rice varieties representing different types with specific emphasis given to sali and jum types. The protection against the loss of vast genetic diversity found in indigenous rice varieties in NE India is crucial for maintaining future food security in the changing world. PMID:23741655

  17. Growing season net ecosystem CO2 exchange of two desert ecosystems with alkaline soils in Kazakhstan

    PubMed Central

    Li, Longhui; Chen, Xi; van der Tol, Christiaan; Luo, Geping; Su, Zhongbo

    2014-01-01

    Central Asia is covered by vast desert ecosystems, and the majority of these ecosystems have alkaline soils. Their contribution to global net ecosystem CO2 exchange (NEE) is of significance simply because of their immense spatial extent. Some of the latest research reported considerable abiotic CO2 absorption by alkaline soil, but the rate of CO2 absorption has been questioned by peer communities. To investigate the issue of carbon cycle in Central Asian desert ecosystems with alkaline soils, we have measured the NEE using eddy covariance (EC) method at two alkaline sites during growing season in Kazakhstan. The diurnal course of mean monthly NEE followed a clear sinusoidal pattern during growing season at both sites. Both sites showed significant net carbon uptake during daytime on sunny days with high photosynthetically active radiation (PAR) but net carbon loss at nighttime and on cloudy and rainy days. NEE has strong dependency on PAR and the response of NEE to precipitation resulted in an initial and significant carbon release to the atmosphere, similar to other ecosystems. These findings indicate that biotic processes dominated the carbon processes, and the contribution of abiotic carbon process to net ecosystem CO2 exchange may be trivial in alkaline soil desert ecosystems over Central Asia. PMID:24455157

  18. Lessons on River Ecosystems

    NSDL National Science Digital Library

    Dan Zalles

    The lesson activity titles are: What are systems? (Purpose: to have students understand what a "system" is, in the broadest sense) How is the natural environment of the tribal community a system? (Purpose: to tie what students learned during the year about the tribal community and its natural environment to the concept of what a "system" is) How did settlers of European descent change the tribe's ecosystem? (Purpose: to explore the connections between what European settlers did to the tribe's ecosystem and what the effects have been on the ecosystem) What can be done? What should be done? (Purpose: to explore and evaluate policy options for future environmental sustenance)

  19. Biochemical Characterization of Rice Glutelin 1

    PubMed Central

    Wen, Tuan-Nan; Luthe, Dawn S.

    1985-01-01

    The two major subunits of rice glutelin, the acidic (?) and basic (?) polypeptides were purified by chromatofocusing and cation exchange chromatography, respectively. The molecular weight range of the ? polypeptides was 28.5 to 30.8 kilodaltons and the molecular weight range of the ? polypeptides was 20.6 to 21.6 kilodaltons. Electrofocusing in polyacrylamide gels showed that the isoelectric points of the ? and ? polypeptides were 6.5 to 7.5 and 9.4 to 10.3, respectively. At least 12 polypeptides of the ?-group and nine polypeptides of the ?-group could be separated by electrofocusing. The amino acid compositions of whole glutelin, and the purified ? and ? subunits were analyzed. The ? subunit contained more glutamic acid/glutamine, serine, and glycine, and less alanine, lysine, aspartic acid/asparagine, and isoleucine than the ? subunit. A comparison of the amino acid composition of rice glutelin subunits with those of the 11S proteins from eight other plant species indicated that there is more similarity between the ? subunits than the ? subunits of several diverse plant species. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:16664193

  20. Efficacy of Aquatain, a Monomolecular Film, for the Control of Malaria Vectors in Rice Paddies

    PubMed Central

    Bukhari, Tullu; Takken, Willem; Githeko, Andrew K.; Koenraadt, Constantianus J. M.

    2011-01-01

    Background Rice paddies harbour a large variety of organisms including larvae of malaria mosquitoes. These paddies are challenging for mosquito control because their large size, slurry and vegetation make it difficult to effectively apply a control agent. Aquatain, a monomolecular surface film, can be considered a suitable mosquito control agent for such breeding habitats due to its physical properties. The properties allow Aquatain to self-spread over a water surface and affect multiple stages of the mosquito life cycle. Methodology/Principal Findings A trial based on a pre-test/post-test control group design evaluated the potential of Aquatain as a mosquito control agent at Ahero rice irrigation scheme in Kenya. After Aquatain application at a dose of 2 ml/m2 on rice paddies, early stage anopheline larvae were reduced by 36%, and late stage anopheline larvae by 16%. However, even at a lower dose of 1 ml/m2 there was a 93.2% reduction in emergence of anopheline adults and 69.5% reduction in emergence of culicine adults. No pupation was observed in treated buckets that were part of a field bio-assay carried out parallel to the trial. Aquatain application saved nearly 1.7 L of water in six days from a water surface of 0.2 m2 under field conditions. Aquatain had no negative effect on rice plants as well as on a variety of non-target organisms, except backswimmers. Conclusions/Significance We demonstrated that Aquatain is an effective agent for the control of anopheline and culicine mosquitoes in irrigated rice paddies. The agent reduced densities of aquatic larval stages and, more importantly, strongly impacted the emergence of adult mosquitoes. Aquatain also reduced water loss due to evaporation. No negative impacts were found on either abundance of non-target organisms, or growth and development of rice plants. Aquatain, therefore, appears a suitable mosquito control tool for use in rice agro-ecosystems. PMID:21738774