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Sample records for major rice ecosystems

  1. Understanding ecosystem services provided by rice fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While the concept of ecosystem services is not new, there is revived interest in how these services should be measured, monitored, and valued. Focused research over the last four years has provided insight into the mitigation capabilities of rice fields in the lower Mississippi River Valley of the ...

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

    PubMed

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

    2012-01-01

    Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2). PMID:22489497

  3. Understanding the nature of methane emission from rice ecosystems as basis of mitigation strategies

    SciTech Connect

    Buendia, L.V.; Neue, H.U.; Wassmann, R.

    1996-12-31

    Methane is considered as an important Greenhouse gas and rice fields are one of the major atmospheric methane sources. The paper aims to develop sampling strategies and formulate mitigation options based on diel (day and night) and seasonal pattern of methane emission. The study was conducted in 4 countries to measure methane flux using an automatic closed chamber system. A 24-hour bihourly methane emissions were continuously obtained during the whole growing season. Daily and seasonal pattern of methane fluxes from different rice ecosystems were evaluated. Diel pattern of methane emission from irrigated rice fields, in all sites, displayed similar pattern from planting to flowering. Fluxes at 0600, 1200, and 1800 h were important components of the total diel flux. A proposed sampling frequency to accurately estimate methane emission within the growing season was designed based on the magnitude of daily flux variation. Total methane emission from different ecosystems follow the order: deepwater rice > irrigated rice > rainfed rice. Application of pig manure increased total emission by 10 times of that without manure. Green manure application increased emission by 49% of that applied only with inorganic fertilizer. Removal of floodwater at 10 DAP and 35 DAP, within a period of 4 days, inhibited production and emission of methane. The level of variation in daily methane emission and seasonal emission pattern provides useful information for accurate determination of methane fluxes. Characterization of seasonal emission pattern as to ecologies, fertilizer amendments, and water management gives an idea of where to focus mitigation strategies for sustainable rice production.

  4. Dissipation and residue of pymetrozine in rice field ecosystem.

    PubMed

    Zhang, Yanfeng; Zhang, Li; Xu, Peng; Li, Jianzhong; Wang, Huili

    2015-03-01

    The dissipation and residue of pymetrozine in rice field ecosystem were studied based on a novel and reliable analytical method for pymetrozine in paddy water, soil, rice straw, brown rice, and rice husk. The pymetrozine residues were extracted with acetonitrile and cleaned up by Carb-NH2 SPE cartridge and determined by high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS). The dissipation of pymetrozine followed first-order kinetics and its half-lives ranged from 1.7 to 1.8 days in paddy water, 5.1 to 5.7 days in soil, and 2.3 to 2.6 days in rice straw, respectively. At harvest time, the highest final residues of pymetrozine varied in soil among three geographical fields and were below the limit of detection in rice tissues. The recommended dosage was considered to be safe for human beings and animals, and the results were helpful in setting maximum residue limit for pymetrozine in rice. PMID:25655126

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

    PubMed

    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

  7. 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

  8. Influence of the Asian monsoon on net ecosystem carbon exchange in two major ecosystems in Korea

    NASA Astrophysics Data System (ADS)

    Kwon, H.; Kim, J.; Hong, J.; Lim, J.-H.

    2010-05-01

    Considering the feedback in radiation, temperature, and soil moisture with alterations in rainfall patterns, the influence of the changing monsoon on Net Ecosystem CO2 Exchange (NEE) can be critical to the estimation of carbon balance in Asia. In this paper, we examined CO2 fluxes measured by the eddy covariance method from 2004 to 2008 in two major ecosystems in the KoFlux sites in Korea, i.e., the Gwangneung Deciduous forest (GDK) and the Haenam Farmland (HFK). Our objectives were to identify the repeatability of the mid-season depression of NEE encountered at the two sites based on the single-year observation, and to further scrutinize its cause, effect, and interannual variability by using multi-year observations. In both GDK and HFK sites, the mid-season depression of NEE was reproduced each year but with different timing, magnitude, and mechanism. At the GDK site, a predominant factor causing the mid-season depression was a decreased solar radiation and the consequent reduction in Gross Primary Productivity (GPP) during the summer monsoon period. At the HFK site, however, the monsoonal effect was less pronounced and the apparent mid-season depression was mainly a result of the management practices such as cultivation of spring barley and rice transplantation. Other flux observation sites in East Asia also showed a decline in radiation but with a lesser degree during the monsoon season, resulting in less pronounced depression in NEE. In our study, the observed depressions in NEE caused both GDK and HFK sites to become a weaker carbon sink or even a source in the middle of the growing season. On average, the GDK site (with maximum leaf area index of ~5) was a weak carbon sink with NEE of -84 gC m-2 y-1. Despite about 20% larger GPP (of 1321 gC m-2y-1) in comparison with the GDK site, the HFK site (with maximum leaf area index of 3-4) was a weaker carbon sink with NEE of -58 gC m-2 y-1 because of greater ecosystem respiration (of 1263 gC m-2 y-1). These NEE values were near the low end of the ranges reported in the literature for similar ecosystems in mid-latitudes. With the projected trends of the extended length of monsoon with more intensive rainfalls in East Asia, the observed delicate coupling between carbon and hydrological cycles may turn these key ecosystems into carbon neutral.

  9. Using the DayCent Ecosystem Model to Predict Methane Emissions from Wetland Rice Production in Support for Mitigation Efforts

    NASA Astrophysics Data System (ADS)

    Ogle, S. M.; Parton, W. J.; Cheng, K.; Pan, G.

    2014-12-01

    Wetland rice production is a major source of greenhouse gas (GHG) emissions to the atmosphere, and rice production is predicted to increase dramatically in the future due to expected growth in human populations. Mitigating GHG emissions from future rice production is possible with best management practices for water management, residue management and organic amendments. Policy initiatives and programs that promote practices to reduce GHG emissions from rice production will likely need robust methods for quantifying emission reductions. Frameworks based on process-based model provide one alternative for estimating emissions reductions. The advantages of this approach are that the models are relatively inexpensive to apply, incorporate a variety of management and environmental drivers influencing emissions, and can be used to predict future emissions for planning purposes. The disadvantages are that the models can be challenging to parameterize and evaluate, and require a relatively large amount of data. The DayCent ecosystem model simulates plant and soil processes, and is an example of a model that could be used to quantify emission reductions for reporting mitigation activities associated with rice production systems. DayCent estimates methane emissions, which is the major source of GHG emissions from wetland rice, but also estimates nitrous oxide emissions and soil organic C stock changes. DayCent has been evaluated using data from China, explaining 83% of the variation in methane emissions from 72 experimental rice fields. In addition, DayCent has been applied regionally in the United States to estimate methane, nitrous oxide emissions, and soil C stock changes, in compliance with the guidelines for reporting GHG emissions to the UN Framework Convention on Climate Change. Given the cost of alternatives, process-based models such as DayCent may offer the best way forward for estimating GHG emissions from rice production, and with quantification of uncertainty, could provide a robust framework for policy initiatives and programs in the future.

  10. Effects of fire on major forest ecosystem processes: an overview.

    PubMed

    Chen, Zhong

    2006-09-01

    Fire and fire ecology are among the best-studied topics in contemporary ecosystem ecology. The large body of existing literature on fire and fire ecology indicates an urgent need to synthesize the information on the pattern of fire effects on ecosystem composition, structure, and functions for application in fire and ecosystem management. Understanding fire effects and underlying principles are critical to reduce the risk of uncharacteristic wildfires and for proper use of fire as an effective management tool toward management goals. This overview is a synthesis of current knowledge on major effects of fire on fire-prone ecosystems, particularly those in the boreal and temperate regions of the North America. Four closely related ecosystem processes in vegetation dynamics, nutrient cycling, soil and belowground process and water relations were discussed with emphases on fire as the driving force. Clearly, fire can shape ecosystem composition, structure and functions by selecting fire adapted species and removing other susceptible species, releasing nutrients from the biomass and improving nutrient cycling, affecting soil properties through changing soil microbial activities and water relations, and creating heterogeneous mosaics, which in turn, can further influence fire behavior and ecological processes. Fire as a destructive force can rapidly consume large amount of biomass and cause negative impacts such as post-fire soil erosion and water runoff, and air pollution; however, as a constructive force fire is also responsible for maintaining the health and perpetuity of certain fire-dependent ecosystems. Considering the unique ecological roles of fire in mediating and regulating ecosystems, fire should be incorporated as an integral component of ecosystems and management. However, the effects of fire on an ecosystem depend on the fire regime, vegetation type, climate, physical environments, and the scale of time and space of assessment. More ecosystem-specific studies are needed in future, especially those focusing on temporal and spatial variations of fire effects through long-term experimental monitoring and modeling. PMID:17147189

  11. Tracing the allocation of water in rainfed rice ecosystem by partitioning evapotranspiration of rainfed rice (Oryza Sativa L.)

    NASA Astrophysics Data System (ADS)

    Nay-Htoon, Bhone; Dubbert, Maren; Wei, Xue; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    To understand productive and unproductive water use of crop production, partitioning evapotranspiration (ET ) into evaporation (E) and transpiration (T ) is important. Water movements within the eco-hydrologic cycle of agroecosystems can be traced by stable oxygen isotopes of water (δ18O) and plant transpiration and soil evaporation can also be estimated by tracing the δ18O. We quantified the contribution of transpiration to total ecosystem evapotranspiration of rainfed rice field by a stable oxygen isotope approach and FAO 56 dual crop modelling approach. Our study aims to provide quantification of ecosystem water cycle of rainfed rice by partitioning productive and unproductive water use since productivity and water use of rice which is a highly water demanding agroecosystem, is under intense research. Crop season total evapotranspiration fluxes from rainfed rice was mainly dominated by transpiration (T to ET contribution (T /ET ) = 65%) and domination of transpiration over evaporation fluxes was noted since early vegetative stage (Leaf Area Index = 0.8 m2 m-2) until harvesting. T /ET of rainfed rice fluctuated with changes in soil water content (SWC) and the highest T /ET was found at SWC of 0.34 m3 m-3, during seedling stage. Our results demonstrate that partitioning ET by FAO 56 dual crop model is in a good agreement with δ18O isotope based ET partitioning results. Using monthly mean values of leaf resistance and vegetation index derived crop coefficients instead of original fixed parameters of the FAO 56 dual crop model resulted better agreement with δ18O isotope based ET partitioning.

  12. 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.

  13. 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...

  14. 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

  15. A major QTL controlling deep rooting on rice chromosome 4

    PubMed Central

    Uga, Yusaku; Yamamoto, Eiji; Kanno, Noriko; Kawai, Sawako; Mizubayashi, Tatsumi; Fukuoka, Shuichi

    2013-01-01

    Drought is the most serious abiotic stress that hinders rice production under rainfed conditions. Breeding for deep rooting is a promising strategy to improve the root system architecture in shallow-rooting rice cultivars to avoid drought stress. We analysed the quantitative trait loci (QTLs) for the ratio of deep rooting (RDR) in three F2 mapping populations derived from crosses between each of three shallow-rooting varieties (‘ARC5955', ‘Pinulupot1', and ‘Tupa729') and a deep-rooting variety, ‘Kinandang Patong'. In total, we detected five RDR QTLs on chromosomes 2, 4, and 6. In all three populations, QTLs on chromosome 4 were found to be located at similar positions; they explained from 32.0% to 56.6% of the total RDR phenotypic variance. This suggests that one or more key genetic factors controlling the root growth angle in rice is located in this region of chromosome 4. PMID:24154623

  16. Evaluating health of paddy rice field ecosystem with remote sensing and GIS in Lower Yangtze River Plain, China

    NASA Astrophysics Data System (ADS)

    Li, Jingjing; Qin, Zhihao; Li, Wenjuan; Lin, Lu

    2008-10-01

    A paddy rice ecosystem is a farming system composed of paddy, animals, microbes and other environmental factors in specific time and space, with particular temporal and spatial dynamics. Since paddy rice is a main grain crop to feed above half of population in China, the performance of paddy rice ecosystem is highly concerned to yield level of paddy and food supply safety in China. Therefore, monitoring the performance of paddy rice ecosystem is very important to obtain the required information for evaluation of ecosystem health. In the study we intend to develop an approach to monitor the ecosystem performance spatially and dynamically in a regional scale using MODIS remote sensing data and GIS spatial mapping. On the basis of key factors governing the paddy rice ecosystem, we accordingly develop the following three indicators for the evaluation: Crop growing index (CGI), environmental Index (EI), and pests-diseases index (PDI). Then, we integrated the three indicators into a model with different weight coefficients to calculate Comprehensive ecosystem health index (CEHI) to evaluate the performance and functioning of paddy rice ecosystem in a regional scale. CGI indicates the health status of paddy rice calculated from the normalizing enhanced vegetation Index (EVI) retrieved from MODIS data. EI is estimated from temperature Index (TI) and precipitation Index (PI) indicating heat and water stress on the rice field. PDI reflects the damage brought by pests and diseases, which can be estimated using the information obtained from governmental websites. Applying the approach to Lower Yangtze River Plain, we monitor and evaluate the performance of paddy rice ecosystem in various stages of rice growing period in 2006. The results indicated that the performance of the ecosystem was generally very encouraging. During booting stage and heading and blooming stage, the health level was the highest in Anhui province, which is the main paddy rice producer in the region. During stage of yellow ripeness, Jiangsu province had the lowest level of performance. Yield level of paddy rice in 2006 confirms that the applicability of the proposed approach for a rapid evaluation and monitoring of agricultural ecosystem performance in Lower Yangtze River Plain. As a result, the new approach could supply scientific basis for relevant departments taking policies and measures to make sure stable development of paddy yield.

  17. 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 μg 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

  18. ENVIRONMENTAL IMPACT ASSESSMENT OF BIO-ETHANOL MADE FROM RICE STRAW CONSIDERING LAND OCCUPATION EFFECTS ON ECOSYSTEM

    NASA Astrophysics Data System (ADS)

    Motoshita, Masaharu; Yang, Cuifen; Genchi, Yutaka; Tahara, Kiyotaka; Inaba, Atsushi

    Most of rice straw produced as a byproduct is not or low utilized in Japan. However, it may be available for the production of bio-ethanol without threatening food supply because of its characteristics as one of the lignocellulosic materials. Though it has already been revealed in previous studies that bio-ethanol made from rice straw can contribute to reducing energy consumption and repressing greenhouse gas emissions, effects on ecosystem due to land occupation for rice straw production and ethanol refinery plant have not been evaluated. Thus, environmental impacts of bio-ethanol made from rice straw including effects on ecosystem caused by land occupation were evaluated in this study. Some differences among three representative assessment methods could be found in results of the effect on ecosystem due to land occupation for rice straw production and ethanol refinery plant. However, it is common among all assessment methods that the effect on ecosystem caused by land occupation dominates large part of total environmental impact of ethanol made from rice straw (72-83% of total impact). Bio-ethanol made from rice straw showed larger environmental impact compared to that of gasoline due to land occupation. The improvement of the operating rate and the productivity of ethanol refinery plants is especially necessary for repressing the environm ental impacts related to bio-ethanol production made from rice straw.

  19. 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-μECD 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 2 mg kg(-1) (mg L(-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) mg L(-1) and 2.09×10(-3) mg L(-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 7.5 days, 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 2.41 mg L(-1) within 14 days, 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

  20. Identification and quantification of major species of arsenic in rice.

    PubMed

    D'Amato, Marilena; Forte, Giovanni; Caroli, Sergio

    2004-01-01

    A study was undertaken to develop a method for the chemical speciation of As in rice on the basis of current knowledge in this field for use in preparing a certified reference material (CRM). Samples of the Arborio rice variety were ground to a fine powder, which was extracted under sonication with a water-methanol mixture (1 + 1, v/v). The resulting solutions were injected into a high-performance liquid chromatograph combined on-line with a quadrupole inductively coupled plasma-mass spectrometer. This hyphenated system allowed for the quantification of As species in one analytical step. Four forms of As were detected: inorganic As (III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and inorganic As (V) at concentrations of 88.2 +/- 7.1, 50.8 +/- 5.0, 15.2 +/- 1.7, and 51.2 +/- 3.5 ng/g, respectively. The concentration of total As was 211 +/- 7 ng/g. The limits of detection (3sigma criterion) and the quantitation (10sigma criterion) were, respectively, as follows (in ng/g): As (III), 0.095 and 0.320; As (V), 0.082 and 0.273; MMA, 0.110 and 0.367; and DMA, 0.145 and 0.480. Ten hours were needed for the extraction procedure, 6 h for the evaporation, and 30 min for quantification of the analytes. This investigation was performed in the frame of a European Commission Project on the feasibility of CRMs for As and Se species. PMID:15084106

  1. Major Ecosystems in China: Dynamics and Challenges for Sustainable Management

    NASA Astrophysics Data System (ADS)

    Lü, Yihe; Fu, Bojie; Wei, Wei; Yu, Xiubo; Sun, Ranhao

    2011-07-01

    Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere. Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland, and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change) and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world. To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and socioeconomic systems. Any change in China's ecosystem management approach towards a more sustainable one will benefit the whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded.

  2. Major ecosystems in China: dynamics and challenges for sustainable management.

    PubMed

    Lü, Yihe; Fu, Bojie; Wei, Wei; Yu, Xiubo; Sun, Ranhao

    2011-07-01

    Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere. Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland, and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change) and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world. To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and socioeconomic systems. Any change in China's ecosystem management approach towards a more sustainable one will benefit the whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded. PMID:21553106

  3. Characterization of rice (Oryza sativa L.) genotypes on the basis of morpho-physiological and biochemical traits grown under aerobic situation in rainfed ecosystem .

    PubMed

    Kumar, Santosh; Dwivedi, Sharad Kumar; Singh, S S; Kumar, Sanjeev; Sundaram, R K; Shivani; Mall, A K

    2015-07-01

    The objective of the present study was to examine the effect of aerobic situation on yield, physiological and biochemical traits of advanced breeding lines of rice. Experiment was conducted with two set of rice genotypes under two water regimes (aerobic and irrigated), during three consecutive wet seasons 2010-2012. Significant decrease in yield was observed in rice genotypes grown under aerobic situation as compared to the irrigated ones. Promising rice genotypes having the ability to maintain high plant biomass, harvest index, early vegetative vigour, improved physiological and biochemical traits in terms of relative water content (RWC), leaf area index (LAI), total soluble sugar, starch, protien and proline content help to sustain higher grain yield under aerobic situation. The yield gap between aerobic and irrigated rice ranged between 24% to 68%. Grain yield showed positive correlation with harvest index (0.434), test weight (0.647), plant biomass (0.411) and effective tiller numbers (0.473), whereas spikelet sterility was negative associated (-0.380). The current study suggested that promising genotypes viz., IR77298-14-1-2-130-2, IR84899-B-182-3-1-1-2, IR84887-B-157-38-1-1-3 and IR 84899-B-179-1-1-1-2 for aerobic situation, showing yield advantage due to better performance of physiological and biochemical traits, might be adopted in large area of rainfed ecosystem as well as in irrigated areas where water scarcity was a major problem. PMID:26364481

  4. 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

  5. New insight for two major rice blast R genes: Pi-ta and Pi-km

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In rice breeding programs across the world, the introgression of major resistance (R) genes remains the most cost-effective method to control blast epidemics caused by the fungal pathogen Magnaporthe oryzae. During the last two years, we have examined two loci, on chromosome 12 and 11, which harbor ...

  6. 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

  7. A Major Ecosystem Shift in the Northern Bering Sea

    NASA Astrophysics Data System (ADS)

    Grebmeier, Jacqueline M.; Overland, James E.; Moore, Sue E.; Farley, Ed V.; Carmack, Eddy C.; Cooper, Lee W.; Frey, Karen E.; Helle, John H.; McLaughlin, Fiona A.; McNutt, S. Lyn

    2006-03-01

    Until recently, northern Bering Sea ecosystems were characterized by extensive seasonal sea ice cover, high water column and sediment carbon production, and tight pelagic-benthic coupling of organic production. Here, we show that these ecosystems are shifting away from these characteristics. Changes in biological communities are contemporaneous with shifts in regional atmospheric and hydrographic forcing. In the past decade, geographic displacement of marine mammal population distributions has coincided with a reduction of benthic prey populations, an increase in pelagic fish, a reduction in sea ice, and an increase in air and ocean temperatures. These changes now observed on the shallow shelf of the northern Bering Sea should be expected to affect a much broader portion of the Pacific-influenced sector of the Arctic Ocean.

  8. 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

  9. Application of a terrestrial ecosystem model (ORCHIDEE-STICS) in simulating energy and CO2 fluxes in Asian rice croplands

    NASA Astrophysics Data System (ADS)

    Wang, X.; Piao, S.; Ciais, P.; Vuichard, N.

    2012-12-01

    Process-based terrestrial ecosystem models have shown great potentials in predicting the response of managed ecosystems to environmental changes. However, the simulated water and carbon fluxes over rice ecosystems in tropical Asia are still subject to large uncertainties, partly due to poorly constrained parameters in the models. Here, a terrestrial ecosystem model incorporating a more realistic crop module (ORCHIDEE-STICS) was calibrated against in-situ flux data and observed and remotely sensed leaf area indexes over rice ecosystems in Asia. The key parameters adjusted include maximum photosynthetic carboxylation rate (Vcmax) and electron transport rate (Vjmax), temperature sensitivity of heterotrophic respiration (Q10) and a series of critical thresholds for different crop development stages. Compared with the observations, the calibrated model more realistically simulated the seasonal and year-to-year variation of the observed water and carbon fluxes with reductions in the root mean square difference and better timing in the crop development stages. Sensitivity tests further reveal that management practices like the timing of transplanting and draining could affect the seasonal and inter-annual variation of the net carbon exchange, suggesting that the absence of explicit accounting the change of management practices in the terrestrial ecosystem models may induce large uncertainties in predicting cropland ecosystem response to future climate change.

  10. Carbon and water cycling in flooded and rainfed rice (Oryza Sativa) ecosystem: Disentangling agronomical and ecological aspects of water use efficiency

    NASA Astrophysics Data System (ADS)

    Nay-Htoon, Bhone; Xue, Wei; Dubbert, Maren; Lindner, Steve; Cuntz, Matthias; Ko, Jonghan; Tenhunen, John; Werner, Christiane

    2015-04-01

    Agricultural crops play an important role in the global carbon and water cycling process and there is intense research to understand and predict carbon and water fluxes, productivity and water use of cultivated crops under climate change. Mechanistic understanding of the trade of between ecosystem water use efficiency and agronomic water use efficiency to maintain higher crop yield and productive water loss is necessary for the ecosystem sustainability. . We compared water and carbon fluxes of paddy and rainfed rice by canopy scale gas exchange measurements, crop growth, and daily evapotranspiration, transpiration and carbon flux modeling. According to our findings, evaporation contributed strongly (maximum 100% to minimum 45%) to paddy rice evapotranspiration while transpiration of rainfed is almost 50 % of daily evapotranspiration. Water use efficiency (WUE) was higher in rainfed rice both from an agronomic (WUEagro, i.e. grain yield per evapotranspiration) and ecosystem (WUEeco, i.e. gross primary production per evapotranspiration) perspective. However, rainfed rice showed also high ecosystem respiration losses and a slightly lower crop yield, demonstrating that higher WUE in rainfed rice comes at the expense of higher respiration losses of assimilated carbon and lower plant production, compared to paddy rice. Our results highlighted the need to partition water and carbon fluxes to improve our mechanistic understanding of water use efficiency and environmental impact of different agricultural practices. Keywords: Rainfed rice, Paddy rice, water use efficiency, Transpiration/Evapotranspiration, ecosystem WUE, agronomic WUE, Evapotranspiration

  11. 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

  12. Modeling impacts of water and fertilizer management on ecosystem services from rice rotated crop systems in China

    NASA Astrophysics Data System (ADS)

    Chen, Han; Yu, Chaoqing; Li, Changsheng; Huang, Xiao; Zhang, Jie; Yue, Yali; Huang, Guorui

    2015-04-01

    Sustainable intensification in agriculture has stressed the need for management practices that could increase crop yields while simultaneously reducing environmental impacts. It is well recognized that water and nutrient management hold great promise to address these goals. This study uses the DNDC biogeochemical model to stimulate the impacts of water regime and nitrogen fertilizer management interactions on ecosystem services of rice rotated crop systems in China. County-level optimal nitrogen fertilizer application rates under various water management practices were captured and then multiple scenarios of water and nitrogen fertilizer management were set to more than 1600 counties with rice rotations in China. Results indicate that an national average of 15.7±5.9% (the mean value and standard deviation derive from variability of three water management practices) reduction of nitrogen fertilizer inputs can be achieved without significantly sacrificing rice yields. On a national scale, shallow flooding with optimal N application rates appear most potential to enhance ecosystem services, which led to 10.6% reduction of nitrogen fertilizer inputs, 34.3% decrease of total GHG emissions, 2.8% less of overall N loss (NH3 volatilization, denitrification and N leaching) and a 1.7% increase of rice yields compared to the baseline scenario. Regional GHG emissions mitigation derived from water regime change vary with soil properties and the multiple crop index. Among the main production regions of rice in China, the highest reduction happened in Jiangxu, Yunnan, Guizhou and Hubei (more than 40% reduction) with high SOC, high multiple crop index and low clay fraction. The highest reduction of GHG emissions derived from reducing current N application rate to optimal rate appeared in Zhejiang, Guangdong, Jiangsu where the serious over-application of mineral N exit. It was concluded that process models like DNDC would act an essential tool to identify sustainable agricultural management practices and evaluate their impacts on agro-ecosystem services.

  13. Linkages and Interactions Analysis of Major Effect Drought Grain Yield QTLs in Rice

    PubMed Central

    Vikram, Prashant; Swamy, B. P. Mallikarjuna; Dixit, Shalabh; Trinidad, Jennylyn; Sta Cruz, Ma Teresa; Maturan, Paul C.; Amante, Modesto; Kumar, Arvind

    2016-01-01

    Quantitative trait loci conferring high grain yield under drought in rice are important genomic resources for climate resilient breeding. Major and consistent drought grain yield QTLs usually co-locate with flowering and/or plant height QTLs, which could be due to either linkage or pleiotropy. Five mapping populations used for the identification of major and consistent drought grain yield QTLs underwent multiple-trait, multiple-interval mapping test (MT-MIM) to estimate the significance of pleiotropy effects. Results indicated towards possible linkages between the drought grain yield QTLs with co-locating flowering and/or plant height QTLs. Linkages of days to flowering and plant height were eliminated through a marker-assisted breeding approach. Drought grain yield QTLs also showed interaction effects with flowering QTLs. Drought responsiveness of the flowering locus on chromosome 3 (qDTY3.2) has been revealed through allelic analysis. Considering linkage and interaction effects associated with drought QTLs, a comprehensive marker-assisted breeding strategy was followed to develop rice genotypes with improved grain yield under drought stress. PMID:27018583

  14. Linkages and Interactions Analysis of Major Effect Drought Grain Yield QTLs in Rice.

    PubMed

    Vikram, Prashant; Swamy, B P Mallikarjuna; Dixit, Shalabh; Trinidad, Jennylyn; Sta Cruz, Ma Teresa; Maturan, Paul C; Amante, Modesto; Kumar, Arvind

    2016-01-01

    Quantitative trait loci conferring high grain yield under drought in rice are important genomic resources for climate resilient breeding. Major and consistent drought grain yield QTLs usually co-locate with flowering and/or plant height QTLs, which could be due to either linkage or pleiotropy. Five mapping populations used for the identification of major and consistent drought grain yield QTLs underwent multiple-trait, multiple-interval mapping test (MT-MIM) to estimate the significance of pleiotropy effects. Results indicated towards possible linkages between the drought grain yield QTLs with co-locating flowering and/or plant height QTLs. Linkages of days to flowering and plant height were eliminated through a marker-assisted breeding approach. Drought grain yield QTLs also showed interaction effects with flowering QTLs. Drought responsiveness of the flowering locus on chromosome 3 (qDTY3.2) has been revealed through allelic analysis. Considering linkage and interaction effects associated with drought QTLs, a comprehensive marker-assisted breeding strategy was followed to develop rice genotypes with improved grain yield under drought stress. PMID:27018583

  15. A major quantitative trait locus controlling cadmium translocation in rice (Oryza sativa).

    PubMed

    Ueno, D; Kono, I; Yokosho, K; Ando, T; Yano, M; Ma, J F

    2009-01-01

    The trait of low cadmium (Cd) accumulation in brown rice (Oryza sativa) is important for food safety. An effective way to reduce Cd accumulation in the grain is to control Cd transfer from the roots to the shoots. Here, we investigated genotypic variation in the shoot Cd concentration among 146 accessions from a rice core collection and performed a quantitative trait locus (QTL) analysis to determine the loci controlling shoot Cd accumulation. Furthermore, we physiologically characterized the two accessions used for QTL analysis. Large genotypic variation (13-fold) in the shoot Cd concentration was found. A major QTL was detected on chromosome 11 using a F2 population derived from Badari Dhan (a high-Cd accession) and Shwe War (a low-Cd accession). This QTL explained 16.1% of the phenotypic variation in Cd accumulation. Furthermore, this QTL was confirmed by analysis of advanced progeny. Physiological studies showed that Badari Dhan and Shwe War did not differ in uptake of Cd by the roots, but differed greatly in the translocation of Cd from the roots to the shoots. Taken together, our findings suggest that the major QTL detected is responsible for the translocation of Cd from the roots to the shoots. PMID:19309445

  16. Differences in net global warming potential and greenhouse gas intensity between major rice-based cropping systems in China

    PubMed Central

    Xiong, Zhengqin; Liu, Yinglie; Wu, Zhen; Zhang, Xiaolin; Liu, Pingli; Huang, Taiqing

    2015-01-01

    Double rice (DR) and upland crop-single rice (UR) systems are the major rice-based cropping systems in China, yet differences in net global warming potential (NGWP) and greenhouse gas intensity (GHGI) between the two systems are poorly documented. Accordingly, a 3-year field experiment was conducted to simultaneously measure methane (CH4) and nitrous oxide (N2O) emissions and changes in soil organic carbon (SOC) in oil rape-rice-rice and wheat-rice (representing DR and UR, respectively) systems with straw incorporation (0, 3 and 6 t/ha) during the rice-growing seasons. Compared with the UR system, the annual CH4, N2O, grain yield and NGWP were significantly increased in the DR system, though little effect on SOC sequestration or GHGI was observed without straw incorporation. Straw incorporation increased CH4 emission and SOC sequestration but had no significant effect on N2O emission in both systems. Averaged over the three study years, straw incorporation had no significant effect on NGWP and GHGI in the UR system, whereas these parameters were greatly increased in the DR system, i.e., by 108% (3 t/ha) and 180% (6 t/ha) for NGWP and 103% (3 t/ha) and 168% (6 t/ha) for GHGI. PMID:26626733

  17. Differences in net global warming potential and greenhouse gas intensity between major rice-based cropping systems in China.

    PubMed

    Xiong, Zhengqin; Liu, Yinglie; Wu, Zhen; Zhang, Xiaolin; Liu, Pingli; Huang, Taiqing

    2015-01-01

    Double rice (DR) and upland crop-single rice (UR) systems are the major rice-based cropping systems in China, yet differences in net global warming potential (NGWP) and greenhouse gas intensity (GHGI) between the two systems are poorly documented. Accordingly, a 3-year field experiment was conducted to simultaneously measure methane (CH4) and nitrous oxide (N2O) emissions and changes in soil organic carbon (SOC) in oil rape-rice-rice and wheat-rice (representing DR and UR, respectively) systems with straw incorporation (0, 3 and 6 t/ha) during the rice-growing seasons. Compared with the UR system, the annual CH4, N2O, grain yield and NGWP were significantly increased in the DR system, though little effect on SOC sequestration or GHGI was observed without straw incorporation. Straw incorporation increased CH4 emission and SOC sequestration but had no significant effect on N2O emission in both systems. Averaged over the three study years, straw incorporation had no significant effect on NGWP and GHGI in the UR system, whereas these parameters were greatly increased in the DR system, i.e., by 108% (3 t/ha) and 180% (6 t/ha) for NGWP and 103% (3 t/ha) and 168% (6 t/ha) for GHGI. PMID:26626733

  18. Differences in net global warming potential and greenhouse gas intensity between major rice-based cropping systems in China

    NASA Astrophysics Data System (ADS)

    Xiong, Zhengqin; Liu, Yinglie; Wu, Zhen; Zhang, Xiaolin; Liu, Pingli; Huang, Taiqing

    2015-12-01

    Double rice (DR) and upland crop-single rice (UR) systems are the major rice-based cropping systems in China, yet differences in net global warming potential (NGWP) and greenhouse gas intensity (GHGI) between the two systems are poorly documented. Accordingly, a 3-year field experiment was conducted to simultaneously measure methane (CH4) and nitrous oxide (N2O) emissions and changes in soil organic carbon (SOC) in oil rape-rice-rice and wheat-rice (representing DR and UR, respectively) systems with straw incorporation (0, 3 and 6 t/ha) during the rice-growing seasons. Compared with the UR system, the annual CH4, N2O, grain yield and NGWP were significantly increased in the DR system, though little effect on SOC sequestration or GHGI was observed without straw incorporation. Straw incorporation increased CH4 emission and SOC sequestration but had no significant effect on N2O emission in both systems. Averaged over the three study years, straw incorporation had no significant effect on NGWP and GHGI in the UR system, whereas these parameters were greatly increased in the DR system, i.e., by 108% (3 t/ha) and 180% (6 t/ha) for NGWP and 103% (3 t/ha) and 168% (6 t/ha) for GHGI.

  19. Residues of carbosulfan and its metabolites carbofuran and 3-hydroxy carbofuran in rice field ecosystem in China.

    PubMed

    Zhang, Chang P; He, Hong M; Yu, Jian Z; Hu, Xiu Q; Zhu, Ya H; Wang, Qiang

    2016-06-01

    The fate of carbosulfan (seed treatment dry powder) was studied in rice field ecosystem, and a simple and reliable analytical method was developed for determination of carbosulfan, carbofuran, and 3-hydroxyl carbofuran in brown rice, rice straw, paddy water, and soil. The target compounds were extracted using acetonitrile or dichloromethane, cleaned up on acidic alumina or florisil solid phase extraction (SPE) cartridge, and analyzed by gas chromatography. The average recoveries of carbosulfan, carbofuran and 3-hydroxy carbofuran in brown rice, rice straw, paddy water, and soil ranged from 72.71% to 105.07%, with relative standard deviations of 2.00-8.80%. The limits of quantitation (LOQs) of carbosulfan, carbofuran and 3-hydroxy carbofuran in the samples (brown rice, rice straw, paddy water and soil) were 0.011, 0.0091, 0.014, 0.010 mg kg(-1), 0.016, 0.019, 0.025, 0.013 mg kg(-1), and 0.031, 0.039, 0.035, 0.036 mg kg(-1), respectively. The trials results showed that the half-lives of carbosulfan, carbofuran and 3-hydroxy carbofuran in rice straw were 4.0, 2.6 days, 3.9, 6.0 days, and 5.8, 7.0 days in Zhejiang and Hunan, respectively. Carbosulfan, carbofuran and 3-hydroxy carbofuran were detected in soils. Carbosulfan and 3-hydroxy carbofuran were almost undetectable in paddy water. Carbofuran was detected in paddy water. The final residues of carbosulfan, carbofuran and 3-hydroxy carbofuran in brown rice were lower than 0.05 mg kg(-1), which were lower than 0.5 mg kg(-1) (MRL of carbosulfan) or 0.1 mg kg(-1) (MRL of carbofuran). Therefore, a dosage of 420 g active ingredient per 100 kg seed was recommended, which could be considered as safe to human beings and animals. These would contribute to provide the scientific basis of using this insecticide. PMID:26963425

  20. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests

    PubMed Central

    Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

    2008-01-01

    Background Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which ~21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Results Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. Conclusion In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high entomotoxic effects, imparted appreciable resistance against three major sap-sucking insects. Our results amply demonstrate that transgenic indica rice harbouring asal exhibit surpassing resistance against BPH, GLH and WBPH insects. The prototypic asal transgenic rice lines appear promising for direct commercial cultivation besides serving as a potential genetic resource in recombination breeding. PMID:18854007

  1. [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

  2. Water management impacts on arsenic behavior and rhizosphere bacterial communities and activities in a rice agro-ecosystem.

    PubMed

    Das, Suvendu; Chou, Mon-Lin; Jean, Jiin-Shuh; Liu, Chia-Chuan; Yang, Huai-Jen

    2016-01-15

    Although rice cultivated under water-saturated conditions as opposed to submerged conditions has received considerable attention with regard to reducing As levels in rice grain, the rhizosphere microbiome potentially influencing As-biotransformation and bioavailability in a rice ecosystem has rarely been studied. In this study, the impacts of flooded, non-flooded and alternate wetting and drying (AWD) practices on rhizosphere bacterial composition and activities that could potentially impact As speciation and accumulation in rhizosphere soil and pore water, As fractions in rhizosphere soil and As speciation and distribution in plant parts were assessed. The results revealed that in addition to pore water As concentration, non-specifically sorbed As fraction, specifically sorbed As fraction and amorphous iron oxide bound As fraction in soil were bio-available to rice plants. In the flooded treatment, As(III) in the pore water was the predominant As species, accounting for 87.3-93.6% of the total As, whereas in the non-flooded and AWD treatments, As(V) was the dominant As species, accounting for 89.6-96.2% and 73.0-83.0%, respectively. The genera Ohtaekwangia, Geobacter, Anaeromyxobacter, Desulfuromonas, Desulfocapsa, Desulfobulbus, and Lacibacter were found in relatively high abundance in the flooded soil, whereas the genera Acinetobacter, Ignavibacterium, Thiobacillus, and Lysobacter were detected in relatively high abundance in the non-flooded soil. Admittedly, the decrease in As level in rice cultivated under the non-flooded and AWD conditions was mostly linked to a relatively high soil redox potential, low As(III) concentration in the soil pore water, a decrease in the relative abundance of As-, Fe- and sulfur-reducing bacteria and an increase in the relative abundance of As-, Fe- and sulfur-oxidizing bacteria in the rhizosphere soil of the rice. This study demonstrated that with substantial reduction in grain As levels and higher water productivity, AWD practice in rice cultivation should be favored over the non-flooded and continuously flooded rice cultivations in As-contaminated sites. PMID:26546760

  3. 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.

  4. Biophysical controls on interannual variability in ecosystem-scale CO2 and CH4 exchange in a California rice paddy

    NASA Astrophysics Data System (ADS)

    Knox, Sara Helen; Matthes, Jaclyn Hatala; Sturtevant, Cove; Oikawa, Patricia Y.; Verfaillie, Joseph; Baldocchi, Dennis

    2016-03-01

    We present 6.5 years of eddy covariance measurements of fluxes of methane (FCH4) and carbon dioxide (FCO2) from a flooded rice paddy in Northern California, USA. A pronounced warming trend throughout the study associated with drought and record high temperatures strongly influenced carbon (C) budgets and provided insights into biophysical controls of FCO2 and FCH4. Wavelet analysis indicated that photosynthesis (gross ecosystem production, GEP) induced the diel pattern in FCH4, but soil temperature (Ts) modulated its amplitude. Forward stepwise linear models and neural networking modeling were used to assess the variables regulating seasonal FCH4. As expected due to their competence in modeling nonlinear relationships, neural network models explained considerably more of the variance in daily average FCH4 than linear models. During the growing season, GEP and water levels typically explained most of the variance in daily average FCH4. However, Ts explained much of the interannual variability in annual and growing season CH4 sums. Higher Ts also increased the annual and growing season ratio of FCH4 to GEP. The observation that the FCH4 to GEP ratio scales predictably with Ts may help improve global estimates of FCH4 from rice agriculture. Additionally, Ts strongly influenced ecosystem respiration, resulting in large interannual variability in the net C budget at the paddy, emphasizing the need for long-term measurements particularly under changing climatic conditions.

  5. 40 CFR Table 2c to Subpart Zzzz of... - Requirements for Existing Compression Ignition Stationary Rice Located at Major Sources of HAP...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of 40 CFR 63.6(g) for alternative work practices. ... Ignition Stationary Rice Located at Major Sources of HAP Emissions 2c Table 2c to Subpart ZZZZ of Part 63... Stationary Rice Located at Major Sources of HAP Emissions As stated in §§ 63.6600 and 63.6640, you...

  6. Monitoring seasonal progress of rice stubble burning in major rice growing districts of Haryana, India, using multidate AWiFS data

    NASA Astrophysics Data System (ADS)

    Yadav, M.; Prawasi, R.; Jangra, S.; Rana, P.; Kumari, K.; Lal, S.; Jakhar, K.; Sharma, S.; Hooda, R. S.

    2014-11-01

    The present paper describes the methodology and results of assessment of seasonal progress of rice stubble burning for 10 major rice growing districts of Haryana state in India. These 10 districts contribute about 84 per cent of total rice area of the state. As the rice fields are immediately required to be vacated for the sowing of next crop the farmers opt for mechanized harvesting and easy way out of burning the stubbles in the field. Such burning result in release of polluting gases and aerosols. Besides, the heating of the soil kills the useful micro-flora of the soil causing soil degradation. Multi-date AWiFS data from Resourcesat 1 and 2 satellites acquired between October 16, 2013 to November 26, 2013 were used for estimating paddy stubble burning areas at different intervals for the year 2013 crop growing season. In season collected ground truth data using hand held GPS along with field photographs were used to identify paddy stubble burning areas and other land features. Complete enumeration approach and Iterative Self-organizing Data Analysis Technique (ISODATA) unsupervised classifier was used for digital analysis. Normalized Difference Vegetation Index (NDVI) of each date was also used with other spectral bands of temporal images. To improve the classification accuracy the non-agricultural areas were masked out. The area was estimated by computing pixels under the classified image mask. Progress of paddy stubble burning was estimated at different intervals for the year 2013 using available cloud free multi-date IRS-P6 AWiFS data to identify the crucial period when stubbles burning takes place in major area so that preventive measures can be taken to curb the menace.

  7. Decision tools for bacterial blight resistance gene deployment in rice-based agricultural ecosystems

    PubMed Central

    Dossa, Gerbert S.; Sparks, Adam; Cruz, Casiana Vera; Oliva, Ricardo

    2015-01-01

    Attempting to achieve long-lasting and stable resistance using uniformly deployed rice varieties is not a sustainable approach. The real situation appears to be much more complex and dynamic, one in which pathogens quickly adapt to resistant varieties. To prevent disease epidemics, deployment should be customized and this decision will require interdisciplinary actions. This perspective article aims to highlight the current progress on disease resistance deployment to control bacterial blight in rice. Although the model system rice-Xanthomonas oryzae pv. oryzae has distinctive features that underpin the need for a case-by-case analysis, strategies to integrate those elements into a unique decision tool could be easily extended to other crops. PMID:25999970

  8. 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

  9. Multiple major QTL lead to stable yield performance of rice cultivars across varying drought intensities

    PubMed Central

    2014-01-01

    Background Availability of irrigation water is becoming a major limiting factor in rice cultivation. Production in rainfed areas is affected in particular by drought events, as these areas are commonly planted to high-yielding drought-susceptible rice (Oryza sativa L.) varieties. The use of bulk segregant analysis (BSA), taking grain yield (GY) as a selection criterion, has resulted in the identification of several large-effect QTL. A QTL mapping study was undertaken on a BC1F3:4 population developed from the cross IR55419-04/2*TDK1 with the aim of identifying large-effect QTL in the background of TDK1, a popular variety from Lao PDR. Results The study identified three QTL—qDTY 3.1 (RM168-RM468), qDTY 6.1 (RM586-RM217), and qDTY 6.2 (RM121-RM541)—for grain yield under drought. qDTY 3.1 and qDTY 6.1 , showed consistent effect across seasons under lowland drought-stress conditions while qDTY 6.1 and qDTY 6.2 showed effect under both upland and lowland drought conditions. The test of QTL effect, conducted through a QTL class analysis, showed the complimentary nature of qDTY 3.1 and qDTY 6.1 . Both QTL showed specific patterns of effect across different maturity groups within the mapping population and higher stability for grain yield was seen across stress levels for lines with both QTLs as compared to those with single or no QTL. Conclusions The study offers a clear understanding of large-effect QTL for grain yield under drought and their effect as individual QTL and in various combinations. The study also opens up an opportunity to develop a drought-tolerant version of TDK1 through marker-assisted backcross breeding and has led to a large-scale QTL pyramiding program aiming to combine these QTL with Sub1 in the background of TDK1 as recipient variety. PMID:24491154

  10. How to measure ecosystem stability? An evaluation of the reliability of stability metrics based on remote sensing time series across the major global ecosystems.

    PubMed

    De Keersmaecker, Wanda; Lhermitte, Stef; Honnay, Olivier; Farifteh, Jamshid; Somers, Ben; Coppin, Pol

    2014-07-01

    Increasing frequency of extreme climate events is likely to impose increased stress on ecosystems and to jeopardize the services that ecosystems provide. Therefore, it is of major importance to assess the effects of extreme climate events on the temporal stability (i.e., the resistance, the resilience, and the variance) of ecosystem properties. Most time series of ecosystem properties are, however, affected by varying data characteristics, uncertainties, and noise, which complicate the comparison of ecosystem stability metrics (ESMs) between locations. Therefore, there is a strong need for a more comprehensive understanding regarding the reliability of stability metrics and how they can be used to compare ecosystem stability globally. The objective of this study was to evaluate the performance of temporal ESMs based on time series of the Moderate Resolution Imaging Spectroradiometer derived Normalized Difference Vegetation Index of 15 global land-cover types. We provide a framework (i) to assess the reliability of ESMs in function of data characteristics, uncertainties and noise and (ii) to integrate reliability estimates in future global ecosystem stability studies against climate disturbances. The performance of our framework was tested through (i) a global ecosystem comparison and (ii) an comparison of ecosystem stability in response to the 2003 drought. The results show the influence of data quality on the accuracy of ecosystem stability. White noise, biased noise, and trends have a stronger effect on the accuracy of stability metrics than the length of the time series, temporal resolution, or amount of missing values. Moreover, we demonstrate the importance of integrating reliability estimates to interpret stability metrics within confidence limits. Based on these confidence limits, other studies dealing with specific ecosystem types or locations can be put into context, and a more reliable assessment of ecosystem stability against environmental disturbances can be obtained. PMID:24777443

  11. 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.

  12. 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.

  13. Persistent natural acidification drives major distribution shifts in marine benthic ecosystems.

    PubMed

    Linares, C; Vidal, M; Canals, M; Kersting, D K; Amblas, D; Aspillaga, E; Cebrián, E; Delgado-Huertas, A; Díaz, D; Garrabou, J; Hereu, B; Navarro, L; Teixidó, N; Ballesteros, E

    2015-11-01

    Ocean acidification is receiving increasing attention because of its potential to affect marine ecosystems. Rare CO2 vents offer a unique opportunity to investigate the response of benthic ecosystems to acidification. However, the benthic habitats investigated so far are mainly found at very shallow water (less than or equal to 5 m depth) and therefore are not representative of the broad range of continental shelf habitats. Here, we show that a decrease from pH 8.1 to 7.9 observed in a CO2 vent system at 40 m depth leads to a dramatic shift in highly diverse and structurally complex habitats. Forests of the kelp Laminaria rodriguezii usually found at larger depths (greater than 65 m) replace the otherwise dominant habitats (i.e. coralligenous outcrops and rhodolith beds), which are mainly characterized by calcifying organisms. Only the aragonite-calcifying algae are able to survive in acidified waters, while high-magnesium-calcite organisms are almost completely absent. Although a long-term survey of the venting area would be necessary to fully understand the effects of the variability of pH and other carbonate parameters over the structure and functioning of the investigated mesophotic habitats, our results suggest that in addition of significant changes at species level, moderate ocean acidification may entail major shifts in the distribution and dominance of key benthic ecosystems at regional scale, which could have broad ecological and socio-economic implications. PMID:26511045

  14. The root microbiome influences scales from molecules to ecosystems: The unseen majority.

    PubMed

    Rout, Marnie E; Southworth, Darlene

    2013-09-01

    Plants are teeming with microbial organisms including those that colonize internal tissues as well as those that adhere to external surfaces. In the rhizosphere, the plant-associated microbiome is intricately involved in plant health and serves as a reservoir of additional genes that plants can access when needed. Microbiome regulation of plant trait expression affects plant performance, which in turn influences various ecosystem functions, such as primary productivity and soil health. Understanding these plant- and microbe-driven interactions requires a study of the nature and effects of the plant microbiome. Conceptualizing the microbiome requires a synthesis of microbial ecology, physiology, and bioinformatics, integrated with insight into host biology and ecology. Microbiome structure and function analyses are recognized as essential components to understand the genetic and functional capacity of the host (previously assigned solely to the host) and include vital aspects of metabolism and physiology. Here, as a special section, we present a set of papers that address the complex interactions between plants and root microbiomes in the rhizosphere. This unseen majority spans scales; with its microorganisms numerically dominant in terrestrial ecosystems, the root microbiome is also involved in plant genetics through integral roles in plant trait expression that can effect community composition and ecosystem functions, such as soil health. PMID:24008514

  15. 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

  16. [Potential effects of Bt transgenic rice on soil micro-ecosystem].

    PubMed

    Wang, Zhonghua

    2005-12-01

    With the increasing commercial use of genetically modified crops (GMCs), it is quite important to assess their potential ecological risk. The likelihood of genes dispersal from GMCs to related wild species, the tolerance of insects to insect-resistant GMCs, and the potential impact of GMCs on biodiversity have been extensively investigated. This article reviewed the potential ecological risk assessment of transgenic Bt rice-expressed products, including the persistence characteristics of Bt insecticidal crystal proteins in soil, and their effects on soil culturable microbial flora and soil enzyme activities, which could provide useful information for related researches. PMID:16515209

  17. Rice SPX-Major Facility Superfamily3, a Vacuolar Phosphate Efflux Transporter, Is Involved in Maintaining Phosphate Homeostasis in Rice1[OPEN

    PubMed Central

    Ying, Yinghui; Wang, Shoudong; Secco, David; Liu, Yu; Whelan, James; Tyerman, Stephen D.; Shou, Huixia

    2015-01-01

    To maintain a stable cytosol phosphate (Pi) concentration, plant cells store Pi in their vacuoles. When the Pi concentration in the cytosol decreases, Pi is exported from the vacuole into the cytosol. This export is mediated by Pi transporters on the tonoplast. In this study, we demonstrate that SYG1, PHO81, and XPR1 (SPX)-Major Facility Superfamily (MFS) proteins have a similar structure with yeast (Saccharomyces cerevisiae) low-affinity Pi transporters Phosphatase87 (PHO87), PHO90, and PHO91. OsSPX-MFS1, OsSPX-MFS2, and OsSPX-MFS3 all localized on the tonoplast of rice (Oryza sativa) protoplasts, even in the absence of the SPX domain. At high external Pi concentration, OsSPX-MFS3 could partially complement the yeast mutant strain EY917 under pH 5.5, which lacks all five Pi transporters present in yeast. In oocytes, OsSPX-MFS3 was shown to facilitate Pi influx or efflux depending on the external pH and Pi concentrations. In contrast to tonoplast localization in plants cells, OsSPX-MFS3 was localized to the plasma membrane when expressed in both yeast and oocytes. Overexpression of OsSPX-MFS3 results in decreased Pi concentration in the vacuole of rice tissues. We conclude that OsSPX-MFS3 is a low-affinity Pi transporter that mediates Pi efflux from the vacuole into cytosol and is coupled to proton movement. PMID:26424157

  18. 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 0-15 cm layer, and 22.7% and 26.0% in the 15-30 cm 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 δ15N 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

  19. Major phenolic compounds, antioxidant capacity and antidiabetic potential of rice bean (Vigna umbellata L.) in China.

    PubMed

    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 μg/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 μM·TE/g), in α-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

  20. 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.

  1. Combination Patterns of Major R Genes Determine the Level of Resistance to the M. oryzae in Rice (Oryza sativa L.)

    PubMed Central

    Yu, Ling; Pan, Cunhong; Li, Yuhong; Zhang, Xiaoxiang; Liu, Guangqing; Dai, Zhengyuan; Pan, Xuebiao; Li, Aihong

    2015-01-01

    Rice blast caused by Magnaporthe oryzae is the most devastating disease of rice and poses a serious threat to world food security. In this study, the distribution and effectiveness of 18 R genes in 277 accessions were investigated based on pathogenicity assays and molecular markers. The results showed that most of the accessions exhibited some degree of resistance (resistance frequency, RF >50%). Accordingly, most of the accessions were observed to harbor two or more R genes, and the number of R genes harbored in accessions was significantly positively correlated with RF. Some R genes were demonstrated to be specifically distributed in the genomes of rice sub-species, such as Pigm, Pi9, Pi5 and Pi1, which were only detected in indica-type accessions, and Pik and Piz, which were just harbored in japonica-type accessions. By analyzing the relationship between R genes and RF using a multiple stepwise regression model, the R genes Pid3, Pi5, Pi9, Pi54, Pigm and Pit were found to show the main effects against M. oryzae in indica-type accessions, while Pita, Pb1, Pik, Pizt and Pia were indicated to exhibit the main effects against M. oryzae in japonica-type accessions. Principal component analysis (PCA) and cluster analysis revealed that combination patterns of major R genes were the main factors determining the resistance of rice varieties to M. oryzae, such as ‘Pi9+Pi54’, ‘Pid3+Pigm’, ‘Pi5+Pid3+Pigm’, ‘Pi5+Pi54+Pid3+Pigm’, ‘Pi5+Pid3’ and ‘Pi5+Pit+Pid3’ in indica-type accessions and ‘Pik+Pib’, ‘Pik+Pita’, ‘Pik+Pb1’, ‘Pizt+Pia’ and ‘Pizt+Pita’ in japonica-type accessions, which were able to confer effective resistance against M. oryzae. The above results provide good theoretical support for the rational utilization of combinations of major R genes in developing rice cultivars with broad-spectrum resistance. PMID:26030358

  2. Differential analyses of major allergen proteins in wild-type rice and rice producing a fragment of anti-rotavirus antibody.

    PubMed

    Yuki, Yoshikazu; Kurokawa, Shiho; Kozuka-Hata, Hiroko; Tokuhara, Daisuke; Mejima, Mio; Kuroda, Masaharu; Oyama, Masaaki; Nishimaki-Mogami, Tomoko; Teshima, Reiko; Kiyono, Hiroshi

    2016-04-01

    To develop oral antibody therapy against rotavirus infection, we previously produced a recombinant fragment of llama heavy-chain antibody to rotavirus (ARP1) in rice seeds (MucoRice-ARP1). We intend to use a purification-free rice powder for clinical application but needed to check whether MucoRice-ARP1 had increased levels of known allergen proteins. For this purpose, we used two-dimensional fluorescence difference gel electrophoresis to compare the allergen protein levels in MucoRice-ARP1 and wild-type rice. We detected no notable differences, except in the levels of α-amylase/trypsin inhibitor-like family proteins. Because by this approach we could not completely separate ARP1 from the proteins of this family, we confirmed the absence of changes in the levels of these allergens by using shotgun mass spectrometry as well as immunoblot. By using immunoelectron microscopy, we also showed that RAG2, a member of the α-amylase/trypsin inhibitor-like protein family, was relocated from protein bodies II to the plasma membrane or cell wall in MucoRice-ARP1 seed. The relocation did not affect the level of RAG2. We demonstrated that most of the known rice allergens were not considerably upregulated by the genetic modification in MucoRice-ARP1. Our data suggest that MucoRice-ARP1 is a potentially safe oral antibody for clinical application. PMID:26851506

  3. 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...

  4. 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

  5. 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

  6. Interacting factors driving a major loss of large trees with cavities in a forest ecosystem.

    PubMed

    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

  7. 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

  8. Nucleotide diversity analysis of three major bacterial blight resistance genes in rice.

    PubMed

    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 (π = 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

  9. Spatial abundance and human biting rate of Anopheles arabiensis and Anopheles funestus in savannah and rice agro-ecosystems of Central Tanzania.

    PubMed

    Mboera, Leonard E G; Bwana, Veneranda M; Rumisha, Susan F; Stanley, Grades; Tungu, Patrick K; Malima, Robert C

    2015-01-01

    This study was carried out to determine the spatial variations in malaria mosquito abundance and human biting rate in five villages representing rice-irrigation and savannah ecosystems in Kilosa District, central Tanzania. The study involved five villages namely Tindiga and Malui (wetland/rice irrigation), Twatwatwa and Mbwade (dry savannah) and Kimamba (wet savannah). Indoor mosquitoes were sampled using Centers for Disease Control and Prevention light traps in three houses in each village. Anopheles gambiae s.l. molecular identification was carried out using polymerase chain reaction (PCR). A total of 936 female mosquitoes were collected. About half (46.9%) were malaria mosquitoes (Anopheles gambiae s.l.=28.6%; An. funestus= 18.3%). A total of 161 (60.1%) of the morphologically identified An. gambiae s.l. (268) and subjected to PCR analysis for speciation were genotyped as An. arabiensis. The An. funestus complex mosquitoes were composed of An. funestus funestus and An. rivulorum at the 5:1 ratio. On average, 17.9 Anopheles mosquitoes were collected per village per day. Two-thirds (62.8%) of the malaria mosquitoes were collected in Malui (rice agro-ecosystem) and the lowest number (2.3%) in Twatwatwa (dry savannah ecosystem). The biting rate per person per night for An. arabiensis+An. funestus s.s. was highest in Malui (46.0) and lowest in Twatwatwa (1.67). The parity rate of the An. funestus mosquitoes was lower compared to that of An. arabiensis and none of the mosquitoes was infected with malaria sporozoites. In conclusion, An. arabiensis is the most abundant malaria vector in Kilosa district and its variation is related to the ecological system. The heterogeneity in malaria mosquito abundance and human biting rate could be used to guide selection of locally appropriated control interventions. PMID:26054517

  10. Rice Nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. 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

  12. 13Carbon isotope discrimination in major C4 weeds of rice-implications for root interference studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assessing below ground plant interference in rice has been difficult in the past because separation of intertwined weed and crop roots is nearly impossible. A simple 13C depletion method was previously developed for simultaneous quantification of barnyardgrass and rice roots in flooded fields. Thi...

  13. RICE PI-TA GENE IS CLOSELY LINKED WITH RESISTANCE TO THE MAJOR PATHOTYPES OF THE RICE BLAST FUNGUS IN THE U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Pi-ta gene, allelic to Pi-ta2, in rice is effective in preventing the infection of Magnaporthe grisea isolates containing the corresponding avirulence gene AVR-Pita. Pi-ta encodes a putative cytoplasmic receptor that appears to bind to a predicted processed AVR-Pita to elicit a defense response...

  14. Pyramided rice lines harbouring Allium sativum (asal) and Galanthus nivalis (gna) lectin genes impart enhanced resistance against major sap-sucking pests.

    PubMed

    Bharathi, Y; Vijaya Kumar, S; Pasalu, I C; Balachandran, S M; Reddy, V D; Rao, K V

    2011-03-20

    We have developed transgene pyramided rice lines, endowed with enhanced resistance to major sap-sucking insects, through sexual crosses made between two stable transgenic rice lines containing Allium sativum (asal) and Galanthus nivalis (gna) lectin genes. Presence and expression of asal and gna genes in pyramided lines were confirmed by PCR and western blot analyses. Segregation analysis of F₂ progenies disclosed digenic (9:3:3:1) inheritance of the transgenes. Homozygous F₃ plants carrying asal and gna genes were identified employing genetic and molecular methods besides insect bioassays. Pyramided lines, infested with brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH), proved more effective in reducing insect survival, fecundity, feeding ability besides delayed development of insects as compared to the parental transgenics. Under infested conditions, pyramided lines were found superior to the parental transgenics in their seed yield potential. This study represents first report on pyramiding of two lectin genes into rice exhibiting enhanced resistance against major sucking pests. The pyramided lines appear promising and might serve as a novel genetic resource in rice breeding aimed at durable and broad based resistance against hoppers. PMID:21295625

  15. 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

  16. Effects of tillage practices and straw returning methods on greenhouse gas emissions and net ecosystem economic budget in rice-wheat cropping systems in central China

    NASA Astrophysics Data System (ADS)

    Zhang, Z. S.; Guo, L. J.; Liu, T. Q.; Li, C. F.; Cao, C. G.

    2015-12-01

    Significant efforts have been devoted to assess the effects of conservation tillage (no-tillage [NT] and straw returning) on greenhouse gas (GHG) emissions, global warming potential (GWP), greenhouse gas intensity (GHGI), and net economic budget in crop growing seasons. However, only a few studies have evaluated the effects conservation tillage on the net ecosystem economic budget (NEEB) in a rice-wheat cropping system. Therefore, a split-plot field experiment was performed to comprehensively evaluate the effects of tillage practices (i.e., conventional intensive tillage [CT] and NT) and straw returning methods (i.e., straw returning or removal of preceding crop) on the soil total organic carbon (TOC), GHG emissions, GWP, GHGI, and NEEB of sandy loam soil in a rice-wheat cropping system in central China. Conservation tillage did not affect rice and wheat grain yields. Compared with CT and straw removal, NT and straw returning significantly increased the TOC of 0-5 cm soil layer by 2.9% and 7.8%, respectively. However, the TOC of 0-20 cm soil layer was not affected by tillage practices and straw returning methods. NT did not also affect the N2O emissions during the rice and wheat seasons; NT significantly decreased the annual CH4 emissions by 7.5% and the annual GWP by 7.8% compared with CT. Consequently, GHGI under NT was reduced by 8.1%. Similar to NT, straw returning did not affect N2O emissions during the rice and wheat seasons. Compared with straw removal, straw returning significantly increased annual CH4 emissions by 35.0%, annual GWP by 32.0%, and annual GHGI by 31.1%. Straw returning did not also affect NEEB; by contrast, NT significantly increased NEEB by 15.6%. NT without straw returning resulted in the lowest GWP, the lowest GHGI, and the highest NEEB among all treatments. This finding suggested that NT without straw returning may be applied as a sustainable technology to increase economic and environmental benefits. Nevertheless, environmentally straw returning methods should be considered in future studies.

  17. Confirming a major QTL and finding additional loci responsible for field resistance to brown spot (Bipolaris oryzae) in rice

    PubMed Central

    Sato, Hiroyuki; Matsumoto, Kengo; Ota, Chihiro; Yamakawa, Tomohiro; Kihara, Junichi; Mizobuchi, Ritsuko

    2015-01-01

    Brown spot is a devastating rice disease. Quantitative resistance has been observed in local varieties (e.g., ‘Tadukan’), but no economically useful resistant variety has been bred. Using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) from ‘Tadukan’ (resistant) × ‘Hinohikari’ (susceptible), we previously found three QTLs (qBS2, qBS9, and qBS11) that conferred resistance in seedlings in a greenhouse. To confirm their effect, the parents and later generations of RILs were transplanted into paddy fields where brown spot severely occurred. Three new resistance QTLs (qBSfR1, qBSfR4, and qBSfR11) were detected on chromosomes 1, 4, and 11, respectively. The ‘Tadukan’ alleles at qBSfR1 and qBSfR11 and the ‘Hinohikari’ allele at qBSfR4 increased resistance. The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected. To verify the qBSfR1 and qBSfR11 ‘Tadukan’ resistance alleles, near-isogenic lines (NILs) with one or both QTLs in a susceptible background (‘Koshihikari’) were evaluated under field conditions. NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not. This confirms the effectiveness of qBSfR11. Genetic markers flanking qBSfR11 will be powerful tools for marker-assisted selection to improve brown spot resistance. PMID:26069447

  18. Confirming a major QTL and finding additional loci responsible for field resistance to brown spot (Bipolaris oryzae) in rice.

    PubMed

    Sato, Hiroyuki; Matsumoto, Kengo; Ota, Chihiro; Yamakawa, Tomohiro; Kihara, Junichi; Mizobuchi, Ritsuko

    2015-03-01

    Brown spot is a devastating rice disease. Quantitative resistance has been observed in local varieties (e.g., 'Tadukan'), but no economically useful resistant variety has been bred. Using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) from 'Tadukan' (resistant) × 'Hinohikari' (susceptible), we previously found three QTLs (qBS2, qBS9, and qBS11) that conferred resistance in seedlings in a greenhouse. To confirm their effect, the parents and later generations of RILs were transplanted into paddy fields where brown spot severely occurred. Three new resistance QTLs (qBSfR1, qBSfR4, and qBSfR11) were detected on chromosomes 1, 4, and 11, respectively. The 'Tadukan' alleles at qBSfR1 and qBSfR11 and the 'Hinohikari' allele at qBSfR4 increased resistance. The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected. To verify the qBSfR1 and qBSfR11 'Tadukan' resistance alleles, near-isogenic lines (NILs) with one or both QTLs in a susceptible background ('Koshihikari') were evaluated under field conditions. NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not. This confirms the effectiveness of qBSfR11. Genetic markers flanking qBSfR11 will be powerful tools for marker-assisted selection to improve brown spot resistance. PMID:26069447

  19. 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.

  20. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    PubMed

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs. PMID:27178300

  1. Wet meadow ecosystems contribute the majority of overwinter soil respiration from snow-scoured alpine tundra

    NASA Astrophysics Data System (ADS)

    Knowles, John F.; Blanken, Peter D.; Williams, Mark W.

    2016-04-01

    We measured soil respiration across a soil moisture gradient ranging from dry to wet snow-scoured alpine tundra soils throughout three winters and two summers. In the absence of snow accumulation, soil moisture variability was principally determined by the combination of mesotopographical hydrological focusing and shallow subsurface permeability, which resulted in a patchwork of comingled ecosystem types along a single alpine ridge. To constrain the subsequent carbon cycling variability, we compared three measures of effective diffusivity and three methods to calculate gradient method soil respiration from four typical vegetation communities. Overwinter soil respiration was primarily restricted to wet meadow locations, and a conservative estimate of the rate of overwinter soil respiration from snow-scoured wet meadow tundra was 69-90% of the maximum carbon dioxide (CO2) respired by seasonally snow-covered soils within this same catchment. This was attributed to higher overwinter soil temperatures at wet meadow locations relative to fellfield, dry meadow, and moist meadow communities, which supported liquid water and heterotrophic respiration throughout the winter. These results were corroborated by eddy covariance-based measurements that demonstrated an average of 272 g C m-2 overwinter carbon loss during the study period. As a result, we updated a conceptual model of soil respiration versus snow cover to express the potential for soil respiration variability from snow-scoured alpine tundra.

  2. Water quality of four major lakes in Mississippi, USA: Impacts on human and aquatic ecosystem health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harmful algal blooms (HABs), harmful microorganisms (pathogens) and toxic metals represent three major agents of water quality deterioration. Better water quality is of utmost importance to water bodies that provide recreational opportunities, even better quality is expected in the water bodies that...

  3. 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

  4. 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

  5. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    PubMed

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway. PMID:26207914

  6. 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...

  7. Homology modeling of major intrinsic proteins in rice, maize and Arabidopsis: comparative analysis of transmembrane helix association and aromatic/arginine selectivity filters

    PubMed Central

    Bansal, Anjali; Sankararamakrishnan, Ramasubbu

    2007-01-01

    Background The major intrinsic proteins (MIPs) facilitate the transport of water and neutral solutes across the lipid bilayers. Plant MIPs are believed to be important in cell division and expansion and in water transport properties in response to environmental conditions. More than 30 MIP sequences have been identified in Arabidopsis thaliana, maize and rice. Plasma membrane intrinsic proteins (PIPs), tonoplast intrinsic proteins (TIPs), Nod26-like intrinsic protein (NIPs) and small and basic intrinsic proteins (SIPs) are subfamilies of plant MIPs. Despite sequence diversity, all the experimentally determined structures belonging to the MIP superfamily have the same "hour-glass" fold. Results We have structurally characterized 39 rice and 31 maize MIPs and compared them with that of Arabidopsis. Homology models of 105 MIPs from all three plant species were built. Structure-based sequence alignments were generated and the residues in the helix-helix interfaces were analyzed. Small residues (Gly/Ala/Ser/Thr) are found to be highly conserved as a group in the helix-helix interface of MIP structures. Individual families sometimes prefer one or another of the residues from this group. The narrow aromatic/arginine (ar/R) selectivity filter in MIPs has been shown to provide an important constriction for solute permeability. Ar/R regions were analyzed and compared between the three plant species. Seventeen TIP, NIP and SIP members from rice and maize have ar/R signatures that are not found in Arabidopsis. A subgroup of rice and maize NIPs has small residues in three of the four positions in the ar/R tetrad, resulting in a wider constriction. These MIP members could transport larger solute molecules. Conclusion Small residues are group-conserved in the helix-helix interface of MIP structures and they seem to be important for close helix-helix interactions. Such conservation might help to preserve the hour-glass fold in MIP structures. Analysis and comparison of ar/R selectivity filters suggest that rice and maize MIPs could transport more diverse solutes than Arabidopsis MIPs. Thus the MIP members show conservation in helix-helix interfaces and diversity in aromatic/arginine selectivity filters. The former is related to structural stability and the later can be linked to functional diversity. PMID:17445256

  8. 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

  9. Organic Rice Production: Challenges and Opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. A major quantitative trait locus for increasing cadmium-specific concentration in rice grain is located on the short arm of chromosome 7

    PubMed Central

    Ishikawa, Satoru; Abe, Tadashi; Kuramata, Masato; Yamaguchi, Masayuki; Ando, Tsuyu; Yamamoto, Toshio; Yano, Masahiro

    2010-01-01

    Large phenotypic variations in the cadmium (Cd) concentration of rice grains and shoots have been observed. However, the genetic control of Cd accumulation remains poorly understood. Quantitative trait loci (QTLs) determining the grain Cd concentration of rice grown in a Cd-polluted paddy field were identified. Using a mapping population consisting of 85 backcross inbred lines derived from a cross between the low-Cd-accumulating cultivar Sasanishiki (japonica) and high-Cd-accumulating cultivar Habataki (indica), two QTLs for increasing grain Cd concentration were found on chromosomes 2 and 7. A major-effect QTL, qGCd7 (QTL for grain Cd on chromosome 7), was detected on the short arm of chromosome 7. It accounted for 35.5% of all phenotypic variance in backcross inbred lines. qGCd7 was not genetically related to any QTLs for concentrations of essential trace metals (Cu, Fe, Mn, and Zn) or those for agronomic traits such as heading date, suggesting that this QTL is specific to Cd. Furthermore, the existence of qGCd7 was confirmed using chromosome segment substitution lines (CSSLs) and an F2 population from a cross between the target CSSL and Sasanishiki grown in a Cd-polluted paddy soil. To our knowledge, qGCd7 is a novel QTL with major effects for increasing grain Cd concentrations. PMID:20022924

  11. Transcriptome profiling and physiological studies reveal a major role for aromatic amino acids in mercury stress tolerance in rice seedlings.

    PubMed

    Chen, Yun-An; Chi, Wen-Chang; 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

  12. 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

  13. Screening for resistance against Pseudomonas syringae in rice-FOX Arabidopsis lines identified a putative receptor-like cytoplasmic kinase gene that confers resistance to major bacterial and fungal pathogens in Arabidopsis and rice

    PubMed Central

    Dubouzet, Joseph G; Maeda, Satoru; Sugano, Shoji; Ohtake, Miki; Hayashi, Nagao; Ichikawa, Takanari; Kondou, Youichi; Kuroda, Hirofumi; Horii, Yoko; Matsui, Minami; Oda, Kenji; Hirochika, Hirohiko; Takatsuji, Hiroshi; Mori, Masaki

    2011-01-01

    Approximately 20 000 of the rice-FOX Arabidopsis transgenic lines, which overexpress 13 000 rice full-length cDNAs at random in Arabidopsis, were screened for bacterial disease resistance by dip inoculation with Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). The identities of the overexpressed genes were determined in 72 lines that showed consistent resistance after three independent screens. Pst DC3000 resistance was verified for 19 genes by characterizing other independent Arabidopsis lines for the same genes in the original rice-FOX hunting population or obtained by reintroducing the genes into ecotype Columbia by floral dip transformation. Thirteen lines of these 72 selections were also resistant to the fungal pathogen Colletotrichum higginsianum. Eight genes that conferred resistance to Pst DC3000 in Arabidopsis have been introduced into rice for overexpression, and transformants were evaluated for resistance to the rice bacterial pathogen, Xanthomonas oryzae pv. oryzae. One of the transgenic rice lines was highly resistant to Xanthomonas oryzae pv. oryzae. Interestingly, this line also showed remarkably high resistance to Magnaporthe grisea, the fungal pathogen causing rice blast, which is the most devastating rice disease in many countries. The causal rice gene, encoding a putative receptor-like cytoplasmic kinase, was therefore designated as BROAD-SPECTRUM RESISTANCE 1. Our results demonstrate the utility of the rice-FOX Arabidopsis lines as a tool for the identification of genes involved in plant defence and suggest the presence of a defence mechanism common between monocots and dicots. PMID:20955180

  14. 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

  15. Changes of Major Antioxidant Compounds and Radical Scavenging Activity of Palm Oil and Rice Bran Oil during Deep-Frying

    PubMed Central

    Abdul Hamid, Azizah; Pak Dek, Mohd Sabri; Tan, Chin Ping; Mohd Zainudin, Mohd Asraf; Wee Fang, Evelyn Koh

    2014-01-01

    Changes in antioxidant properties and degradation of bioactives in palm oil (PO) and rice bran oil (RBO) during deep-frying were investigated. The alpha (α)-tocopherol, gamma (γ)-tocotrienol and γ-oryzanol contents of the deep-fried oils were monitored using high performance liquid chromatography, and antioxidant activity was determined using 2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Results revealed that the antioxidant activity of PO decreased significantly (p < 0.05), while that of RBO was preserved after deep-frying of fries. As expected, the concentration of α-tocopherol in PO and γ-tocotrienol in both PO and RBO decreased significantly (p < 0.05) with increased frying. Results also showed that γ-tocotrienol was found to be more susceptible to degradation compared to that of α-tocopherol in both PO and RBO. Interestingly, no significant degradation of α-tocopherol was observed in RBO. It is suggested that the presence of γ-oryzanol and γ-tocotrienol in RBO may have a protective effect on α-tocopherol during deep-frying. PMID:26785067

  16. Profiling of phytohormones and their major metabolites in rice using binary solid-phase extraction and liquid chromatography-triple quadrupole mass spectrometry.

    PubMed

    Cao, Zhao-Yun; Sun, Li-Hua; Mou, Ren-Xiang; Zhang, Lin-Ping; Lin, Xiao-Yan; Zhu, Zhi-Wei; Chen, Ming-Xue

    2016-06-17

    A high-throughput method was developed using liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) for the profiling and quantification of 43 phytohormones and their major metabolites, including auxins, abscisic acid, jasmonic acid, salicylic acid, cytokinins and gibberellins in a single sample extract. Considerable matrix effects (MEs) were observed (with most ME values in the range of 29%-84%, but maximum MEs of more than 115%, even up to 206%, existed) in sample extracts for most of the compounds studied. The application of the proposed binary solid-phase extraction using polymer anion and polymer cation exchange resins, was performed to purify 25 acidic and 18 alkaline phytohormones and their major metabolites prior to the LC-MS/MS analysis, which markedly reduced the MEs to acceptable levels, with ME values in the range of ±15%. Moreover, all of the isomers of cytokinins and their metabolites were fully separated on a sub-2μm particle C18 reverse-phase column with the optimized mobile phase consisting of methanol and 5mM ammonium formate. The method showed good linearity for all 43 analytes with regression coefficients (R(2))>0.991. Limits of detection ranged from 0.19 to 7.57 fmol for auxin, gibberellins, abscisic acid and their metabolites, 29.7 fmol for jasmonic acid, 18.1 fmol for salicylic acid, and from 0.03 to 0.31 fmol for cytokinins and their metabolites. The mean recoveries for all of the analytes were from 70.7 to 118.5%, and the inter-day precisions (n=6) were less than 18.7%, with intra-day precisions (n=6) within 25.4%. Finally, 20 compounds were successfully quantified in rice sample profiles using the proposed method, which will greatly facilitate the understanding of hormone-related regulatory networks that influence rice growth and development. To our knowledge, there are limited reports that measure this level of phytohormone species in rice samples using a single analysis. PMID:27208989

  17. Simultaneous quantification of glyphosate, glufosinate, and their major metabolites in rice and soybean sprouts by gas chromatography with pulsed flame photometric detector.

    PubMed

    Tseng, Su-Hsiang; Lo, Yi-Wen; Chang, Pi-Chiou; Chou, Shin-Shou; Chang, Hung-Min

    2004-06-30

    Procedures were developed for the simultaneous determination of glyphosate [N-(phosphonomethyl)glycine] and glufosinate [dl-homoalanin-4-yl-(methyl)phosphinic acid] and their major metabolites, aminomethylphosphonic acid (AMPA) and 3-(methylphosphinico)propionic acid (3-MPPA), in rice and soybean sprouts by gas chromatography (GC) equipped with a pulsed flame photometric detector (PFPD). Herbicides and their major metabolites were previously derivatized with TMOA (trimethyl orthoacetate (TMOA) in the presence of acetic acid, and their GC responses versus heating temperature (70-90 degrees C) and heating time (30-120 min) were optimized. It was found that increases in heating temperature and heating time were unfavorable for the derivatization of glyphosate or glufosinate, whereas high temperature and extended reaction time remarkably facilitated that of AMPA and 3-MPPA except at 90 degrees C for an extended reaction time (120 min). Combination of AG1-X8 anion-exchange chromatography with a Florisil cartridge cleanup process was favorable for the GC-PFPD analysis. Four types of derivatives spiked in rice and soybean sprout matrices were eluted, reaching a baseline separation, in a sequence of 3-MPPA, AMPA, glyphosate, and glufosinate within 14 min using a DB-608 capillary column. Recoveries of glyphosate, AMPA, glufosinate, and 3-MPPA (0.5 ppm) spiked in both sample matrices were determined to be 72-81, 71-86, 101-119, and 83-90%, respectively, whereas the coefficient of variation was determined to be <10% in three repeated determinations. The instrumental limits of detection for glyphosate, AMPA, glufosinate, and 3-MPPA in sample matrices were 0.02, 0.03, 0.02, and 0.01 ppm, respectively. The limits of quantification for glyphosate, AMPA, glufosinate, and 3-MPPA in sample matrices were 0.06, 0.10, 0.06, and 0.04 ppm, respectively. PMID:15212448

  18. 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

  19. Rice (Oryza) hemoglobins

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. TWELVE RICE GERMPLASM ACCESSIONS IDENTIFIED WITH NOVEL BLAST RESISTANCE FOR US RICE VARIETY IMPROVEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) germplasm accessions with new major resistance (R-) are constantly sought by rice breeders for use in developing resistant cultivars to control blast (Pyricularia oryza Cav.), a major fungal disease of cultivated rice. Initially, 91 blast resistant rice accessions were select...

  1. Effects of tillage during the nonwaterlogged period on nitrous oxide and nitric oxide emissions in typical Chinese rice-wheat rotation ecosystems

    NASA Astrophysics Data System (ADS)

    Yao, Zhisheng; Zhou, Zaixing; Zheng, Xunhua; Xie, Baohua; Liu, Chunyan; Butterbach-Bahl, Klaus; Zhu, Jianguo

    2010-03-01

    Tillage practices result in major changes to soil environmental conditions and to the distribution of crop residues and nutrients in the soil profile, which may consequently affect the biogenic production and emission of N trace gases. To investigate the effects of tillage during the nonwaterlogged period on nitric oxide (NO) and nitrous oxide (N2O) emissions in rice-wheat rotation systems, we performed field experiments at three sites (Suzhou, Wuxi, and Jiangdu) in the Yangtze River Delta using static chamber techniques. The results showed that the effect of tillage on the emissions of both gases differed among the three field sites due to differences in agricultural management and soil texture. At the site with a light soil texture (Jiangdu: sandy loam), no tillage resulted in reduced NO emissions (0.5 kg N ha-1) as compared to conventionally tilled fields (0.9 kg N ha-1; p < 0.05). Regarding N2O, the no tillage plots showed significantly higher emissions (p < 0.05) in comparison to the tilled plots (3.9 versus 2.2 kg N ha-1) when the fields were merely amended with synthetic N fertilizers. However, this effect was not significant when wheat straw was used in addition to synthetic N fertilizers during the preceding rice season. In the clay loam soils (Wuxi), no tillage resulted in lower NO and higher N2O emissions from either N fertilized or unfertilized fields even though these results were not statistically significant. In the silty clay loam soils (Suzhou), which showed the highest soil organic carbon contents and the highest rates of N trace gas emissions in all three of the investigated sites, reduced tillage resulted in much higher NO emissions, whereas N2O emissions were not obviously influenced by tillage practices (reduced tillage versus tillage: NO, 9.5 versus 5.4 kg N ha-1; N2O, 10.6 versus 9.0 kg N ha-1). Similar effects of tillage were observed for the direct emission factors of the applied N during the wheat season. The observed emission factors for the different sites ranged from 0.3% to 2.4% for N2O (mean: 1.0%) and from 0.1% to 4.0% (mean: 0.9%) for NO, respectively. The observed site-to-site differences in emission factors are most likely the results of variations in soil properties (such as texture and pH) and agricultural practices (such as tillage and crop residue management) or in the amount and pattern of precipitation.

  2. 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

  3. 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....

  4. Microbial mechanisms to reduce the uncertainties in the CH4 emissions from global rice fields

    NASA Astrophysics Data System (ADS)

    Kamaljit, K.; Tian, H.; Ren, W.; Yang, J.

    2013-12-01

    In terrestrial ecosystems, methane (CH4) uptake or emission represents the net balance between activities of different microbial organisms including anaerobic Methanogens that produce CH4 and Methanotrophs which oxidize CH4 in the aerobic environments. In this way, anaerobic soil environments such as rice fields are major source of terrestrial CH4 emissions. However, large uncertainties in the CH4 emission estimates have been reported from rice fields. The bottom-up and top-down methods showed a wide range of CH4 emissions estimations ranging from 25 to 300 Tg yr-1 from rice fields. The major reason for uncertainties in the CH4 emissions includes the water management that alters the balance of Methanogens and Methanotrophs in the rice fields. Two kinds of water management practices are followed including continuous flooding (CF) which refers to the continuous submergence as well as alternate wetting and drying (AWD) in which the rice fields are drained for several days during the growing season. The AWD provides aeration stress on Methanogens resulting in lower CH4 emissions than CF water management followed in the rice fields. A single aeration during growing season may significantly reduce the CH4 emission from the rice fields. Currently, most of the models structures assume that Methanogens become active once the soil moisture content is raised to saturation. However, several laboratory scale studies have indicated that following aeration the Methanogens don't become fully functional immediately even if the soil moisture content is raised to saturation. In this study, we integrated the aeration stress mechanisms on the Methanogens in the Dynamic Land Ecosystem Model (DLEM). The improved version of DLEM was used to conduct uncertainty analysis on global CH4 emission estimation following CF and AWD water management in the rice fields. Results of this study have shown that inclusion of the aeration stress mechanism on Methanogens in the modeling framework has reduced the uncertainties in the CH4 emissions estimates from the rice fields.

  5. 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.

    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.

  6. Insights into molecular mechanism of blast resistance in weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy rice is a serious pest in direct-seeded rice fields in the U.S. and worldwide. Under suitable conditions, weedy rice can reduce crop yields up to 70%. However, weedy rice may carry novel disease resistance genes. Rice blast disease caused by the fungus Magnaporthe oryzae is a major disease wo...

  7. Genetic diversity for rice grain mineral concentrations observed among genetically and geographically giverse rice accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With about half of the world’s people dependent on rice as their main food source, improving the nutritional value of rice could have major impact on human health. While rice in the USA is often artificially fortified, natural enhancement of the rice grain’s nutritional value, i.e. from genetic impr...

  8. 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

  9. 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...

  10. Evolutionary insights into the origins of weediness in U.S. red rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy red rice is a widespread, economically challenging problem in Southern U.S. rice fields. The two major U.S. red rice types, strawhull and blackhull, are thought to have arisen independently from Asian rice populations in the distant past. Red rice is a weedy relative of rice, a genomic model...

  11. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida’s Gulf Coast: Implications for Adaptation Planning

    PubMed Central

    Birch, Anne P.; Brenner, Jorge; Gordon, Doria R.

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida’s Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway. PMID:26207914

  12. 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...

  13. 40 CFR Table 2c to Subpart Zzzz of... - Requirements for Existing Compression Ignition Stationary RICE Located at a Major Source of HAP...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... which the risk was deemed unacceptable. 2 Sources have the option to utilize an oil analysis program as... start landfill or digester gas-fired stationary RICE 100 ≤ HP ≤ 500 Limit concentration of CO in the... required schedule would otherwise pose an unacceptable risk under Federal, State, or local law, the...

  14. 40 CFR Table 2c to Subpart Zzzz of... - Requirements for Existing Compression Ignition Stationary RICE Located at a Major Source of HAP...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... which the risk was deemed unacceptable. 2 Sources have the option to utilize an oil analysis program as... start landfill or digester gas-fired stationary RICE 100 ≤ HP ≤ 500 Limit concentration of CO in the... required schedule would otherwise pose an unacceptable risk under Federal, State, or local law, the...

  15. Rice aroma and flavor: a literature review.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aroma and flavor of cooked rice are major criteria for preference among consumers. Small variations in these sensory properties can make rice highly desired or unacceptable to consumers. Human sensory analyses have identified over a dozen different aromas and flavors in rice. Instrumental ana...

  16. [An evaluation of net carbon sink effect and cost/benefits of a rice-rape rotation ecosystem under long-term fertilization from Tai Lake region of China].

    PubMed

    Li, Jie-Jing; Pan, Gen-Xing; Zhang, Xu-Hui; Fei, Qing-Hua; Li, Zhi-Peng; Zhou, Ping; Zheng, Ju-Feng; Qiu, Duo-Sheng

    2009-07-01

    Taking a long-term fertilized rice-rape rotation system in Taihu Lake as test objective, its annual C balance and economic benefit were estimated, based on the measurement of past years grain yield, litter C content, and field CO2 emission as well as the investigation of material and management inputs. The calculated annual C sink under different fertilizations ranged from 0.9 t C x hm(-2) x a(-1) to 7.5 t C x hm(-2) x a(-1), and the net C sink effect under combined inorganic/organic fertilization was three folds as that under chemical fertilization. The C cost of material input ranged from 0.37 t C x hm(-2) x a(-1) to 1.13 t C x hm(-2) x a(-1), and that of management input ranged from 1.69 t C x hm(-2) x a(-1) to 1.83 t C x hm(-2) x a(-1). The annual economic benefit ranged from 5.8 x 10(3) CNY x hm(-2) x a(-1) to 16.5 x 10(3) CNY x hm(-2) x a(-1), and was 2.1 times higher under combined fertilization than under chemical fertilization. Comparing with that under chemical fertilization, the marginal cost for per ton C sink under combined inorganic/organic fertilization was estimated as 217.1 CNY x t(-1) C, very close to the C price of 20 Euro x t(-1) C in the EU. In sum, under combined inorganic/organic fertilization, this rice paddy ecosystem could not only have higher productivity, but also present greater net C sink effect and higher economic benefit, compared with under chemical fertilizer fertilization. PMID:19899468

  17. 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...

  18. Identification of Some Degradation Products of Golden Rice Beta- carotene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Golden Rice (GR2) is genetically modified rice, which can contain as high as 37 ug of beta-carotene per g of dry rice. It was developed to combat vitamin A deficiency (VAD), a major malnutrition problem in many parts of the developing world, especially in South and South Eastern Asia, where rice is ...

  19. Compare and contrast invasive growths and global gene expressions of rice after infections with rice blast and sheath blight pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast and sheath blight diseases are the two major rice diseases that threaten the stable rice production worldwide. The fungus causing rice blast disease is a hemibiotrophic pathogen where the fungus invades host cells biotrophically whereas the fungus causing sheath blight is a necrotrophic ...

  20. Identification and Comparative Expression Profiles of Chemoreception Genes Revealed from Major Chemoreception Organs of the Rice Leaf Folder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).

    PubMed

    Zeng, Fang-Fang; Zhao, Zhen-Fei; Yan, Miao-Jun; Zhou, Wen; Zhang, Zan; Zhang, Aijun; Lu, Zhong-Xian; Wang, Man-Qun

    2015-01-01

    To better understand the olfactory mechanisms in the rice leaf folder, Cnaphalocrocis medinalis (Guenée), a serious pest of rice in Asia, we established six partial transcriptomes from antennae, protarsus, and reproductive organs of male and female adults. A total of 102 transcripts were identified, including 29 odorant receptors (ORs), 15 ionotropic receptors (IRs), 30 odorant-binding proteins (OBPs), 26 chemosensory proteins (CSPs), and 2 sensory neuron membrane proteins (SNMPs). The expression patterns of these genes were calculated by fragments per kilobase of exon per million fragments mapped (FPKM) and validated by real-time quantitative PCR (RT-qPCR). Some transcripts were exclusively expressed in specific organs, such as female protarsus, whereas others were universally expressed, this varied expression profile may provide insights into the specific functions mediated by chemoreception proteins in insects. To the best of our knowledge, among the 102 identified transcripts, 81 are novel and have never been reported before. In addition, it also is the first time that ORs and IRs are identified in C. medinalis. Our findings significantly enhance the currently limited understanding olfactory mechanisms of the olfactory mechanisms underlying the chemoreception system in C. medinalis. PMID:26657286

  1. Identification and Comparative Expression Profiles of Chemoreception Genes Revealed from Major Chemoreception Organs of the Rice Leaf Folder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

    PubMed Central

    Zeng, Fang-Fang; Zhao, Zhen-Fei; Yan, Miao-Jun; Zhou, Wen; Zhang, Zan; Zhang, Aijun; Lu, Zhong-Xian; Wang, Man-Qun

    2015-01-01

    To better understand the olfactory mechanisms in the rice leaf folder, Cnaphalocrocis medinalis (Guenée), a serious pest of rice in Asia, we established six partial transcriptomes from antennae, protarsus, and reproductive organs of male and female adults. A total of 102 transcripts were identified, including 29 odorant receptors (ORs), 15 ionotropic receptors (IRs), 30 odorant-binding proteins (OBPs), 26 chemosensory proteins (CSPs), and 2 sensory neuron membrane proteins (SNMPs). The expression patterns of these genes were calculated by fragments per kilobase of exon per million fragments mapped (FPKM) and validated by real-time quantitative PCR (RT-qPCR). Some transcripts were exclusively expressed in specific organs, such as female protarsus, whereas others were universally expressed, this varied expression profile may provide insights into the specific functions mediated by chemoreception proteins in insects. To the best of our knowledge, among the 102 identified transcripts, 81 are novel and have never been reported before. In addition, it also is the first time that ORs and IRs are identified in C. medinalis. Our findings significantly enhance the currently limited understanding olfactory mechanisms of the olfactory mechanisms underlying the chemoreception system in C. medinalis. PMID:26657286

  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. 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.

    PubMed

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

    2011-09-01

    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 sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important for the genetic manipulation of plant architecture in practical rice breeding. In this study, introgression lines derived from two parents contrasting in plant height, Zhenshan 97 and Pokkali were employed to locate a gene with a large effect on plant height by the bulk segregant analysis method. A major gene, ph1, was mapped to a region closely linked to sd1 on chromosome 1; the additive effects of ph1 were more than 50 cm on the plant height and 2 days on the heading date in a BC(4)F(2) population and its progeny. ph1 was then fine mapped to BAC AP003227. Gene annotation indicated that LOC_OS01g65990 encoding a chitin-inducible gibberellin-responsive protein (CIGR), which belongs to the GRAS family, might be the right candidate gene of ph1. Co-segregation analysis of the candidate gene-derived marker finally confirmed its identity as the candidate gene. A higher expression level of the CIGR was detected in all the tested tissues in tall plants compared to those of short plants, especially in the young leaf sheath containing elongating tissues, which indicated its importance role in regulating plant height. ph1 showed a tremendous genetic effect on plant height, which is distinct from sd1 and could be a new resource for breeding semi-dwarf varieties. PMID:21637999

  4. Identification of possible technical problems in determination of the major inorganic constituents of brown-rice flour by evaluating proficiency test results.

    PubMed

    Miyashita, Shin-ichi; Inagaki, Kazumi; Naito, Shigehiro; Shindoh, Kumiko; Narukawa, Tomohiro; Zhu, Yanbei; Kuroiwa, Takayoshi; Hioki, Akiharu; Fujimoto, Toshiyuki; Chiba, Koichi

    2013-10-01

    To support skill upgrading in analysis of inorganic constituents of environmental and food samples, the National Metrology Institute of Japan (NMIJ) and the National Food Research Institute (NFRI) have organized a proficiency test (PT) of determination of Mn, Fe, Cu, Zn, As, and Cd in brown-rice flour based on the international standard (ISO/IEC 17043:2010). One hundred and thirty-three sets of reports were assessed by use of the E(n)-number and z-score approaches in accordance with ISO/IEC 17043 and the international harmonized protocol for PT. The PT results and analytical procedures, reported in detail, were reviewed, and possible technical reasons for questionable or unsatisfactory results are discussed. PMID:23907683

  5. 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

  6. Preferential Association of Endophytic Bradyrhizobia with Different Rice Cultivars and Its Implications for Rice Endophyte Evolution

    PubMed Central

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

    2015-01-01

    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

  7. Red yeast rice for dysipidemia.

    PubMed

    Shamim, Shariq; Al Badarin, Firas J; DiNicolantonio, James J; Lavie, Carl J; O'Keefe, James H

    2013-01-01

    Red yeast rice is an ancient Chinese food product that contains monacolins, chemical substances that are similar to statins in their mechanisms of action and lipid lowering properties. Several studies have found red yeast rice to be moderately effective at improving the lipid profile, particularly for lowering the low-density lipoprotein cholesterol levels. One large randomized controlled study from China found that red yeast rice significantly improved risk of major adverse cardiovascular events and overall survival in patients following myocardial infarction. Thus, red yeast rice is a potentially useful over-the-counter cholesterol-lowering agent. However, many red yeast rice formulations are non-standardized and unregulated food supplements, and there is a need for further research and regulation of production. PMID:24003656

  8. Development of genetic and molecular toolboxes to control both rice blast and sheath blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast and sheath blight diseases are the two major constraints for stable rice production in the Southern USA. New genetic and molecular tool boxes have been developed at the USDA-ARS Dale Bumpers National Rice Research Center. Resistance (major and minor) genes from rice have been identified...

  9. 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 ...

  10. From QTL to variety-harnessing the benefits of QTLs for drought, flood and salt tolerance in mega rice varieties of India through a multi-institutional network.

    PubMed

    Singh, Renu; Singh, Yashi; Xalaxo, Suchit; Verulkar, S; Yadav, Neera; Singh, Shweta; Singh, Nisha; Prasad, K S N; Kondayya, K; Rao, P V Ramana; Rani, M Girija; Anuradha, T; Suraynarayana, Y; Sharma, P C; Krishnamurthy, S L; Sharma, S K; Dwivedi, J L; Singh, A K; Singh, P K; Nilanjay; Singh, N K; Kumar, Rajesh; Chetia, S K; Ahmad, T; Rai, M; Perraju, P; Pande, Anita; Singh, D N; Mandal, N P; Reddy, J N; Singh, O N; Katara, J L; Marandi, B; Swain, P; Sarkar, R K; Singh, D P; Mohapatra, T; Padmawathi, G; Ram, T; Kathiresan, R M; Paramsivam, K; Nadarajan, S; Thirumeni, S; Nagarajan, M; Singh, A K; Vikram, Prashant; Kumar, Arvind; Septiningshih, E; Singh, U S; Ismail, A M; Mackill, D; Singh, Nagendra K

    2016-01-01

    Rice is a staple cereal of India cultivated in about 43.5Mha area but with relatively low average productivity. Abiotic factors like drought, flood and salinity affect rice production adversely in more than 50% of this area. Breeding rice varieties with inbuilt tolerance to these stresses offers an economically viable and sustainable option to improve rice productivity. Availability of high quality reference genome sequence of rice, knowledge of exact position of genes/QTLs governing tolerance to abiotic stresses and availability of DNA markers linked to these traits has opened up opportunities for breeders to transfer the favorable alleles into widely grown rice varieties through marker-assisted backcross breeding (MABB). A large multi-institutional project, "From QTL to variety: marker-assisted breeding of abiotic stress tolerant rice varieties with major QTLs for drought, submergence and salt tolerance" was initiated in 2010 with funding support from Department of Biotechnology, Government of India, in collaboration with International Rice Research Institute, Philippines. The main focus of this project is to improve rice productivity in the fragile ecosystems of eastern, northeastern and southern part of the country, which bear the brunt of one or the other abiotic stresses frequently. Seven consistent QTLs for grain yield under drought, namely, qDTY1.1, qDTY2.1, qDTY2.2, qDTY3.1, qDTY3.2, qDTY9.1 and qDTY12.1 are being transferred into submergence tolerant versions of three high yielding mega rice varieties, Swarna-Sub1, Samba Mahsuri-Sub1 and IR 64-Sub1. To address the problem of complete submergence due to flash floods in the major river basins, the Sub1 gene is being transferred into ten highly popular locally adapted rice varieties namely, ADT 39, ADT 46, Bahadur, HUR 105, MTU 1075, Pooja, Pratikshya, Rajendra Mahsuri, Ranjit, and Sarjoo 52. Further, to address the problem of soil salinity, Saltol, a major QTL for salt tolerance is being transferred into seven popular locally adapted rice varieties, namely, ADT 45, CR 1009, Gayatri, MTU 1010, PR 114, Pusa 44 and Sarjoo 52. Genotypic background selection is being done after BC2F2 stage using an in-house designed 50K SNP chip on a set of twenty lines for each combination, identified with phenotypic similarity in the field to the recipient parent. Near-isogenic lines with more than 90% similarity to the recipient parent are now in advanced generation field trials. These climate smart varieties are expected to improve rice productivity in the adverse ecologies and contribute to the farmer's livelihood. PMID:26566845

  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. Identification of greenhouse gas hot-spots and predicting district-wise GHG Intensities in rice based crop rotations in India using DNDC model

    NASA Astrophysics Data System (ADS)

    Yeluripati, J. B.; Frolking, S. E.; Li, C.; Nayak, D. R.; Adhya, T. K.

    2014-12-01

    Indian scientific research on rice cultivation has been targeted primarily at enhancing crop productivity for the wide range of soil and climate conditions across India. With the understanding that rice paddies are major source of atmospheric CH4 and N2O, there is a need for careful evaluation of the source strength of this ecosystem, and the influence of soil, water and crop management practices on both CH4 and N2O fluxes. A major challenge in meeting this objective lies in reducing the large uncertainties associated with regional and global level estimates of GHG emissions. Process-based biogeochemical models like DNDC (Denitrification and Decomposition model) can provide important insights into how agricultural management of rice paddies influences water resources, yields and greenhouse gas emissions. To quantify the CH4 and N2­O emissions from rice based crop rotations of India, DNDC model was modified, calibrated and evaluated at different sites across India. The observed N uptake, yields, CH4 and N2O emissions were in agreement with the values predicted by the model. To drive the model across India, a unique database was prepared combining soil/climate/landuse and management information. By linking the spatial database to DNDC, CH4 and N2O emissions from Indian rice based crop rotations for the rice growing season in the year 2000 were simulated on day-by-day basis. CH4 and N2O emissions from rice paddies in India from rice based-growing season were estimated to be 3.8 and 0.1 - 0.08 Tg (1 Tg = 1012 gm). Of the total CH4 emissions 30.6% (1.2 Tg) is emitted from single irrigated rice. 30.0% (1.1 Tg) and 14.46%(0.56 Tg) of total CH4 is emitted from double rice and single rainfed rice cropping system. 32.9% (33.16 Gg) of the total N2O emissions is emitted by upland rice followed by Single rainfed rice cropping system which emits about 19.9%(20.06 Gg) of total N2O . This paper presents a framework on GIS databases and a process-based biogeochemical model for estimation of greenhouse gas emissions from Indian based crop rotations.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice sheath blight caused by Rhizoctonia solani Khn 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...

  15. 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...

  16. Oscillating Transcriptome during Rice-Magnaporthe Interaction.

    PubMed

    Sharma, T R; Das, Alok; Thakur, Shallu; Devanna, B N; Singh, Pankaj Kumar; Jain, Priyanka; Vijayan, Joshitha; Kumar, Shrawan

    2016-01-01

    Rice blast disease caused by the fungus, Magnaporthe oryzae, is one of the most devastating diseases of rice. Deciphering molecular mechanism of host-pathogen interactions is of great importance in devising disease management strategies. Transcription being the first step for gene regulation in eukaryotes, basic understanding of the transcriptome is sine qua non for devising effective management strategy. The availability of genome sequences of rice and M. oryzae has facilitated the process to a large extent. The current review summarizes recent understanding of rice-blast pathosystem, application of transcriptomics approaches to understand the interactions employing different platforms, major determinants in the interaction and possibility of using certain candidate for conditioning enhanced disease resistance (Effector Triggered Immunity and PAMP Triggered Immunity) and downstream signalling in rice. A better understanding of the interaction elements and effective strategies hold potential to reduce yield losses in rice caused by M. oryzae. PMID:26363736

  17. Blackbirds and the southern rice crop

    USGS Publications Warehouse

    Meanley, Brooke

    1971-01-01

    In the 1700's and 1800's, rice was grown in the lowlands of South Carolina, Georgia, and North Carolina - on the major migratory route of the bobolink (Dolichonyx oryzivorus), the historic "ricebird" of that area because of its consumption of ripening rice. By the late 1800's the rice-growing industry had largely shifted to the coastal prairies of Louisiana and Texas, which are bordered by some 5 million acres of marshland-breeding habitat for the redwinged blackbird (Agelaius phoeniceus) and the boat-tailed grackle (Cassidix mexicanus). By 1900, rice was being grown on the Grand Prairie of eastern Arkansas, which bestrides the largest blackbird flyway in the country. In recent decades, rice culture has spread to other sections of Arkansas and thence to contiguous areas in Louisiana, Mississippi, Tennesee, and Missouri. In effect, then, man has taken the rice to the blackbirds.

  18. 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...

  19. Opportunities for the development of rice blast resistant cultivars/germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast is the most serious rice disease in the USA. Both conventional and novel strategies for the development of resistant rice cultivars/germplasm have been employed in the U.S. rice breeding programs. The objectives are to develop molecular markers for stacking major resistance genes into i...

  20. 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...

  1. GENETIC ANALYSIS AND RECIPROCAL OUTCROSSING RATES OF RED RICE TYPES IN ARKANSAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red rice is a severe weed problem in Arkansas rice fields and can intercross at low rates with rice. Using DNA marker analysis and visual observation, red rice accessions obtained from across Arkansas clearly clustered into major groups of awned and awnless types, which were easily distinguishable f...

  2. 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.

  3. Comparative Analyses Between Lolium/Festuca Introgression Lines and Rice Reveal the Major Fraction of Functionally Annotated Gene Models Is Located in Recombination-Poor/Very Recombination-Poor Regions of the Genome

    PubMed Central

    King, Julie; Armstead, Ian P.; Donnison, S. Iain; Roberts, Luned A.; Harper, John A.; Skøt, Kirsten; Elborough, Kieran; King, Ian P.

    2007-01-01

    Publication of the rice genome sequence has allowed an in-depth analysis of genome organization in a model monocot plant species. This has provided a powerful tool for genome analysis in large-genome unsequenced agriculturally important monocot species such as wheat, barley, rye, Lolium, etc. Previous data have indicated that the majority of genes in large-genome monocots are located toward the ends of chromosomes in gene-rich regions that undergo high frequencies of recombination. Here we demonstrate that a substantial component of the coding sequences in monocots is localized proximally in regions of very low and even negligible recombination frequencies. The implications of our findings are that during domestication of monocot plant species selection has concentrated on genes located in the terminal regions of chromosomes within areas of high recombination frequency. Thus a large proportion of the genetic variation available for selection of superior plant genotypes has not been exploited. In addition our findings raise the possibility of the evolutionary development of large supergene complexes that confer a selective advantage to the individual. PMID:17603095

  4. Ecosystem Dynamics in Southeast China during 1981~2000 as Forced by Climate and Human Disturbances

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Tian, H.; Liu, M.; Chen, H.; Ren, W.; Chen, G.; Pan, S.

    2006-05-01

    Southeast China is one of the few regions on earth that have both extremely high population density and intensive urbanization rate due to unprecedented economic development since 1980. Understanding how the climate, natural disturbances and human activities have affected the terrestrial ecosystem is both important for maintaining ecosystem sustainability in this rapidly changed region and for improving our understanding of the interactions among climate, human and terrestrial ecosystems. In this study, we reconstructed annual land- use change dataset, annual tropospheric ozone dataset, annual nitrogen deposition dataset, and daily climate dataset from 1961 to 2000 in Southeast China. We then used these datasets as inputs to the Dynamic Land Ecosystem Model (DLEM), a process-based highly integrated ecosystem model that couples major biogeochemical cycles and hydrological cycle to make daily and spatially-explicit estimates of carbon and nitrogen fluxes (CO2, CH4 and N2O) and pool sizes (C and N) in terrestrial ecosystems. DLEM is able to address responses of terrestrial ecosystems to multiple stresses including changes in climate, atmospheric composition, land use and natural disturbances. The DLEM has been calibrated against several intensively studied ecological research sites in China. Our analysis showed that, land-use change has dominated the ecosystem dynamics of Southeast China from 1980 to 2000. Urbanization was the major land-use change force in Southeast China during the study period. From 1980 to 2000, build-up area in Southeast China increased by 379.6 kilo hectares, while the cropland area declined by 432.2 kilo hectares. The urbanization, together with its byproducts ¡§C air pollution such as increased tropospheric ozone concentration, reduced the ecosystem productivity and carbon storage. Although cropland area continuously declined during the study period, the rice paddy in Southeast China was still an important trace gas source, which released large amount of CH4 into the atmosphere each year. Among the climate factors, the precipitation is the most important controls over the terrestrial ecosystem productivity.

  5. 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

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

    PubMed Central

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

    2013-01-01

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

  9. Morphology based field rice density detection from rice transplant stage to rice jointing stage

    NASA Astrophysics Data System (ADS)

    Bai, X. D.; Cao, Z. G.; Wang, Y.; Ye, M. N.; Yu, Z. H.; Li, Y. N.

    2013-10-01

    Rice yield estimation is an important aspect in the agriculture research field. For the rice yield estimation, rice density is one of its useful factors. In this paper, we propose a new method to automatically detect the rice density from the rice transplanting stage to rice jointing stage. It devotes to detect rice planting density by image low-level features of the rice image sequences taken in the fields. Moreover, a rice jointing stage automatic detection method is proposed so as to terminate the rice density detection algorithm. The validities of the proposed rice density detection method and the rice jointing stage automatic detection method are proved in the experiment.

  10. 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

  11. Natural ecosystems

    USGS Publications Warehouse

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  12. 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…

  13. 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…

  14. 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

  15. Simultaneous determination of Se, trace elements and major elements in Se-rich rice by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) after microwave digestion.

    PubMed

    Wei, Yi Hua; Zhang, Jin Yan; Zhang, Da Wen; Luo, Lin Guang; Tu, Tian Hua

    2014-09-15

    A quick and accurate method was devised to determine Se, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr and Zn in Se-rich rice samples by microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS). Spectral interferences on Se were eliminated using methane as a reaction gas in the dynamic reaction cell (DRC). Rhodium was used as an internal standard to compensate for sample matrix effects. A rice-certified reference material (CRM) (GBW 10010) was used to verify the accuracy of the method. The method detection limits were 0.001-0.03 mg/kg, analyte recoveries were 85-108% and precisions (RSDs) ranged from 2.1% to 5.8%. Correlation analysis showed that the Se concentrations in the Se-rich rice samples correlated well with the Cu concentrations (r=0.53, p<0.05). PMID:24767089

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

    PubMed

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

    2014-11-01

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

  17. Utilizing DNA markers to further identify the blast resistance in indica rice and other Oryza spp. germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blast, Pyricularia grisea Cav., is a major fungal disease of cultivated rice (Oryza sativa L.) in the U.S., and of irrigated rice worldwide. Indica rice, rice grown in tropical areas, and Oryza spp. are possible sources of additional blast resistance genes (Pi-genes) which could be incorporated int...

  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. 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

  20. Budgeting of major nutrients and the mitigation options for nutrient mining in semi-arid tropical agro-ecosystem of Tamil Nadu, India using NUTMON model.

    PubMed

    Surendran, U; Rama Subramoniam, S; Raja, P; Kumar, V; Murugappan, V

    2016-04-01

    Mining of nutrients from soil is a major problem in developing countries causing soil degradation and threaten long-term food production. The present study attempts to apply NUTrient MONitoring (NUTMON) model for carrying out nutrient budgeting to assess the stocks and flows of nitrogen (N), phosphorus (P), and potassium (K) in defined geographical unit based on the inputs, viz., mineral fertilizers, manures, atmospheric deposition, and sedimentation, and outputs, viz., harvested crop produces, residues, leaching, denitrification, and erosion losses. The study area covers Coimbatore and Erode Districts, which are potential agricultural areas in western agro-ecological zone of Tamil Nadu, India. The calculated nutrient balances for both the districts at district scale, using NUTMON methodology, were negative for nitrogen (N -3.3 and -10.1 kg ha(-1)) and potassium (K -58.6 and -9.8 kg ha(-1)) and positive for phosphorus (P +14.5 and 20.5 kg ha(-1)). Soil nutrient pool has to adjust the negative balance of N and K; there will be an expected mining of nutrient from the soil reserve. A strategy was attempted for deriving the fertilizer recommendation using Decision Support System for Integrated Fertilizer Recommendation (DSSIFER) to offset the mining in selected farms. The results showed that when DSSIFER recommended fertilizers are applied to crops, the nutrient balance was positive. NUTMON-Toolbox with DSSIFER would serve the purpose on enhancing soil fertility, productivity, and sustainability. The management options to mitigate nutrient mining with an integrated system approach are also discussed. PMID:27021693

  1. Genetic resources offer efficient tools for rice functional genomics research.

    PubMed

    Lo, Shuen-Fang; Fan, Ming-Jen; Hsing, Yue-Ie; Chen, Liang-Jwu; Chen, Shu; Wen, Ien-Chie; Liu, Yi-Lun; Chen, Ku-Ting; Jiang, Mirng-Jier; Lin, Ming-Kuang; Rao, Meng-Yen; Yu, Lin-Chih; Ho, Tuan-Hua David; Yu, Su-May

    2016-05-01

    Rice is an important crop and major model plant for monocot functional genomics studies. With the establishment of various genetic resources for rice genomics, the next challenge is to systematically assign functions to predicted genes in the rice genome. Compared with the robustness of genome sequencing and bioinformatics techniques, progress in understanding the function of rice genes has lagged, hampering the utilization of rice genes for cereal crop improvement. The use of transfer DNA (T-DNA) insertional mutagenesis offers the advantage of uniform distribution throughout the rice genome, but preferentially in gene-rich regions, resulting in direct gene knockout or activation of genes within 20-30 kb up- and downstream of the T-DNA insertion site and high gene tagging efficiency. Here, we summarize the recent progress in functional genomics using the T-DNA-tagged rice mutant population. We also discuss important features of T-DNA activation- and knockout-tagging and promoter-trapping of the rice genome in relation to mutant and candidate gene characterizations and how to more efficiently utilize rice mutant populations and datasets for high-throughput functional genomics and phenomics studies by forward and reverse genetics approaches. These studies may facilitate the translation of rice functional genomics research to improvements of rice and other cereal crops. PMID:26301381

  2. CHARACTERIZATION OF WEEDY RICE POPULATIONS IN THE SOUTHERN U.S. AND THEIR GENE FLOW INTERACTIONS WITH RICE USING DNA MARKERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy (red) rice (Oryza sativa) is a major weed problem in rice (Oryza sativa) in the southern US. Outcrossing between these plant types can lead to gene flow that negatively impacts the rice industry. We have been using SSR molecular marker analysis in combination with phenotypic traits to systema...

  3. Bioengineered 'golden' indica rice cultivars with beta-carotene metabolism in the endosperm with hygromycin and mannose selection systems.

    PubMed

    Datta, Karabi; Baisakh, Niranjan; Oliva, Norman; Torrizo, Lina; Abrigo, Editha; Tan, Jing; Rai, Mayank; Rehana, Sayda; Al-Babili, Salim; Beyer, Peter; Potrykus, Ingo; Datta, Swapan K

    2003-03-01

    Vitamin-A deficiency (VAD) is a major malnutrition problem in South Asia, where indica rice is the staple food. Indica-type rice varieties feed more than 2 billion people. Hence, we introduced a combination of transgenes using the biolistic system of transformation enabling biosynthesis of provitamin A in the endosperm of several indica rice cultivars adapted to diverse ecosystems of different countries. The rice seed-specific glutelin promoter (Gt-1 P) was used to drive the expression of phytoene synthase (psy), while lycopene beta-cyclase (lcy) and phytoene desaturase (crtI), fused to the transit peptide sequence of the pea-Rubisco small subunit, were driven by the constitutive cauliflower mosaic virus promoter (CaMV35S P). Transgenic plants were recovered through selection with either CaMV35S P driven hph (hygromycin phosphotransferase) gene or cestrum yellow leaf curling virus promoter (CMP) driven pmi (phophomannose isomerase) gene. Molecular and biochemical analyses demonstrated stable integration and expression of the transgenes. The yellow colour of the polished rice grain evidenced the carotenoid accumulation in the endosperm. The colour intensity correlated with the estimated carotenoid content by spectrophotometric and HPLC analysis. Carotenoid level in cooked polished seeds was comparable (with minor loss of xanthophylls) to that in non-cooked seeds of the same transgenic line. The variable segregation pattern in T1 selfing generation indicated single to multiple loci insertion of the transgenes in the genome. This is the first report of using nonantibiotic pmi driven by a novel promoter in generating transgenic indica rice for possible future use in human nutrition. PMID:17147745

  4. 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.

  5. Nutritionally enhanced rice to combat malnutrition disorders of the poor.

    PubMed

    Potrykus, Ingo

    2003-06-01

    Major deficiency disorders, including vitamin A deficiency, are especially common in countries in which rice is the staple food. In response to the devastating effects of vitamin A deficiency, which may include blindness and, even death, "Golden Rice" has been developed to deliver this nutrient to those populations who need it most. The case of Golden Rice is used to demonstrate the challenges of radical GMO opposition, consumer acceptance, and regulation of biotechnology-derived foods. PMID:12908739

  6. Rice Production and Marketing.

    ERIC Educational Resources Information Center

    Briers, Gary; Lee, Jasper S.

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

  7. Range Ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ‘Range Ecosystems’ chapter in the ‘Ecosystems of California’ sourcebook provides an integrated picture of the social, economic, and biophysical aspects of lands grazed by livestock in California. Range forms a diverse class of managed ecosystems covering about a third of the state, primarily in ...

  8. AQUATIC ECOSYSTEMS,

    EPA Science Inventory

    Aquatic ecosystems are a vital part of the urban water cycle (and of urban areas more broadly), and, if healthy, provide a range of goods and services valued by humans (Meyer 1997). For example, aquatic ecosystems (e.g., rivers, lakes, wetlands) provide potable water, food resou...

  9. Relationship between grain yield and quality in rice germplasms grown across different growing areas.

    PubMed

    Xu, Quan; Chen, Wenfu; Xu, Zhengjin

    2015-06-01

    Rice grain yield and quality are two major foci of rice breeding. In this study, Chinese regional rice test data provide us the unique opportunity to analyze the relationship between yield and quality in rice, because China has an unusually wide range of rice cultivars. We analyzed the relationships between grain yield, yield components, and grain quality of 300 rice germplasms. Japonica was superior in both yield and quality compared with indica. A high setting rate improved the head rice ratio. A higher 1000 grain weight was negatively correlated with quality characteristics but had a positive correlation with yield. A high spikelet density (number of grains per centimeter on the panicle) not only benefits the yield but also the head rice ratio and chalkiness traits. According to our results, global rice production can be increased to at least 8500 kg/ha to meet projected demands in 2025 without sacrificing grain quality. PMID:26175619

  10. Relationship between grain yield and quality in rice germplasms grown across different growing areas

    PubMed Central

    Xu, Quan; Chen, Wenfu; Xu, Zhengjin

    2015-01-01

    Rice grain yield and quality are two major foci of rice breeding. In this study, Chinese regional rice test data provide us the unique opportunity to analyze the relationship between yield and quality in rice, because China has an unusually wide range of rice cultivars. We analyzed the relationships between grain yield, yield components, and grain quality of 300 rice germplasms. Japonica was superior in both yield and quality compared with indica. A high setting rate improved the head rice ratio. A higher 1000 grain weight was negatively correlated with quality characteristics but had a positive correlation with yield. A high spikelet density (number of grains per centimeter on the panicle) not only benefits the yield but also the head rice ratio and chalkiness traits. According to our results, global rice production can be increased to at least 8500 kg/ha to meet projected demands in 2025 without sacrificing grain quality. PMID:26175619

  11. 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

  12. Influence of Milling Procedures on Milling Quality of Rough Rice with Varying Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice milling quality is one of the major factors determining the economic value of rough rice in trade. It is normally appraised by milling a rice sample with various bench-scale milling methods. However there is still lack of knowledge about how the sample milling procedures and methods affect th...

  13. Development and evaluation of rice breeding lines for blast resistance at Arkansas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blast and sheath blight are the major diseases of rice in Arkansas. Although environmental conditions and recommended cultural practices help reduce the possibility of widespread rice blast disease epidemic, resistant cultivars provide the primary means of control. Rice farmers in Arkansas prefer ...

  14. 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...

  15. Use of bacillus biocontrol agents for disease management in organic rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic rice production has significantly increased in the U. S. over the last decade. Organic rice growers lack effective tools to manage sheath blight, caused by Rhizoctonia solani, and narrow brown leaf spot, caused by Cercospora janseana, two major diseases affecting organic rice production. Thi...

  16. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

  19. The effect of induced yellowing on the physicochemical properties of specialty rices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Postharvest yellowing of rice kernels, commonly referred to as stackburn or heat damage, can be a major problem in the rice industry. This is especially true with high-valued specialty rice because the discolored grains are removed prior to packaging resulting in a greater profit loss. Specialty r...

  20. 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

  1. Microsatellite markers reveal multiple origins for Italian weedy rice.

    PubMed

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

    2013-11-01

    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

  2. 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

  3. RICE GERMPLASM CHARACTERIZED FOR R-GENES AND POPULATION STRUCTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the USA, newly introduced rice germplasm is one source of novel resistance genes to blast, Magnaporthe grisea, and sheath blight, Rhizoctonia solani, major fungal diseases of irrigated rice (Oryza sativa). Resistance to U.S. blast races was observed in 91 of approximately 1,000 newly introduced ...

  4. Variations in bran carotenoids levels within and between rice subgroups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) is a major grain in the human diet and carotenoids are valuable antioxidants. However, little is known about varietal differences in the carotenoid contents of the rice bran. The objective of this study is to determine the relative differences in bran carotenoid levels among...

  5. 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 Khn and leaf blast, Magnaporthe grisea (T.T. Herbert) Yaegashi & Udagawa, are major fungal d...

  6. 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.

  7. Rice protein-based infant formula: current status and future development.

    PubMed

    Koo, W W K; Lasekan, J B

    2007-02-01

    Rice is the world's leading staple cereal food and is the major source of protein for many parts of the world. Rice is among the first solid foods fed to infants in many cultures, in part because of its hypoallergenicity from lack of gluten. Nutritional quality of rice protein compares favorably with other cereal proteins including wheat, oat and barley. It is rich in methionine and cystine, although as is the case for other cereals, it is an incomplete protein source for human infants with lysine and threonine being the primary limiting amino acids. Fortification of rice proteins with these two limiting amino acids improves its protein quality. Rice protein-based infant formulas (RPF) were initially based on high protein rice flours, but more recently are based on rice protein concentrates, isolates or hydrolysates, fortified with lysine and threonine. Hypoallergenicity efficacy, particularly for hydrolyzed rice protein-based formulas, has been reported, and limited data indicated that rice protein based infant formula may provide potentially adequate alternative if standard milk- or soy protein-based formulas are not tolerated. Unlike the rice-protein based infant formula, rice beverage formulas made from rice flour are nutritionally inadequate for infants. Reports have indicated stunted growth in infants/children fed rice beverage formulas. Future development for the RPF include those based on genetically improved rice with high lysine and threonine content, supplementation with appropriate mineral and fat blend, and long-term clinical studies in infants to confirm its efficacy and safety. PMID:17301723

  8. Development of practical diagnostic methods for monitoring rice bacterial panicle blight disease and evaluation of rice germplasm for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was initiated to understand Burkholderia glumae (major causal agent for bacterial panicle blight disease of rice) to develop practical diagnostic methods for monitoring the disease; and to evaluate rice germplasm for resistance. B. glumae was frequently isolated from symptomatic panicles on...

  9. Development of practical diagnostic methods for monitoring rice bacterial panicle blight disease and evaluation of rice germplasm for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was initiated to understand Burkholderia glumae, the major causal agent for bacterial panicle blight disease of rice; to develop practical diagnostic methods for monitoring the disease; and to evaluate rice germplasm for resistance. Burkholderia glumae was frequently isolated from infected p...

  10. Root-Derived Short-Chain Suberin Diacids from Rice and Rape Seed in a Paddy Soil under Rice Cultivar Treatments.

    PubMed

    Ji, Haishi; Ding, Yuanjun; Liu, Xiaoyu; Li, Lianqing; Zhang, Dengxiao; Li, Zichuan; Sun, Jingling; Lashari, Muhammad Siddique; Joseph, Stephen; Meng, Yuanduo; Kuzyakov, Yakov; Pan, Genxing

    2015-01-01

    Suberin-derived substituted fatty acids have been shown to be potential biomarkers for plant-derived carbon (C) in soils across ecosystems. Analyzing root derived suberin compounds bound in soil could help to understand the root input into a soil organic carbon pool. In this study, bound lipids were extracted and identified in root and topsoil samples. Short-chain suberin diacids were quantified under rice (Oryza sativa L.) and rape (Brassica campestris) rotations with different cultivar combinations in a Chinese rice paddy. After removal of free lipids with sequential extraction, the residual bound lipids were obtained with saponification and derivatization before analysis using gas chromatography-mass spectrometry (GC-MS). Diacids C16 and C18 in bound lipids were detected both in rice and rape root samples, while diacids C20 and C22 were detected only in rape root samples. Accordingly, diacids were quantified in both rhizosphere and bulk soil (0-15 cm). The amount of total root-derived diacids in bulk soil varied in a range of 5.6-9.6 mg/kg across growth stages and crop seasons. After one year-round rice-rape rotation, root-derived suberin diacids were maintained at a level of 7-9 mg/kg in bulk soil; this was higher under a super rice cultivar LY than under a hybrid cultivar IIY. While concentrations of the analyzed diacids were generally higher in rhizosphere than in bulk soil, the total diacid (DA) concentration was higher at the time of rape harvest than at rice harvest, suggesting that rape roots made a major contribution to the preservation of diacids in the paddy. Moreover, the net change in the concentration and the ratios of C16:0 DA to C18:1 DA, and of C16:0 DA to C18:0 DA, over a whole growing season, were greater under LY than under IIY, though there was no difference between cultivars within a single growth stage. Overall, total concentration of root-derived suberin diacids was found to be positively correlated to soil organic carbon concentration both for bulk soil and rhizosphere. However, the turnover and preservation of the root suberin biomolecules with soil property and field conditions deserve further field studies. PMID:25961557

  11. Root-Derived Short-Chain Suberin Diacids from Rice and Rape Seed in a Paddy Soil under Rice Cultivar Treatments

    PubMed Central

    Ji, Haishi; Ding, Yuanjun; Liu, Xiaoyu; Li, Lianqing; Zhang, Dengxiao; Li, Zichuan; Sun, Jingling; Lashari, Muhammad Siddique; Joseph, Stephen; Meng, Yuanduo; Kuzyakov, Yakov; Pan, Genxing

    2015-01-01

    Suberin-derived substituted fatty acids have been shown to be potential biomarkers for plant-derived carbon (C) in soils across ecosystems. Analyzing root derived suberin compounds bound in soil could help to understand the root input into a soil organic carbon pool. In this study, bound lipids were extracted and identified in root and topsoil samples. Short-chain suberin diacids were quantified under rice (Oryza sativa L.) and rape (Brassica campestris) rotations with different cultivar combinations in a Chinese rice paddy. After removal of free lipids with sequential extraction, the residual bound lipids were obtained with saponification and derivatization before analysis using gas chromatography–mass spectrometry (GC-MS). Diacids C16 and C18 in bound lipids were detected both in rice and rape root samples, while diacids C20 and C22 were detected only in rape root samples. Accordingly, diacids were quantified in both rhizosphere and bulk soil (0–15 cm). The amount of total root-derived diacids in bulk soil varied in a range of 5.6–9.6 mg/kg across growth stages and crop seasons. After one year-round rice-rape rotation, root-derived suberin diacids were maintained at a level of 7–9 mg/kg in bulk soil; this was higher under a super rice cultivar LY than under a hybrid cultivar IIY. While concentrations of the analyzed diacids were generally higher in rhizosphere than in bulk soil, the total diacid (DA) concentration was higher at the time of rape harvest than at rice harvest, suggesting that rape roots made a major contribution to the preservation of diacids in the paddy. Moreover, the net change in the concentration and the ratios of C16:0 DA to C18:1 DA, and of C16:0 DA to C18:0 DA, over a whole growing season, were greater under LY than under IIY, though there was no difference between cultivars within a single growth stage. Overall, total concentration of root-derived suberin diacids was found to be positively correlated to soil organic carbon concentration both for bulk soil and rhizosphere. However, the turnover and preservation of the root suberin biomolecules with soil property and field conditions deserve further field studies. PMID:25961557

  12. Genetic shift in local rice populations during rice breeding programs in the northern limit of rice cultivation in the world.

    PubMed

    Fujino, Kenji; Obara, Mari; Ikegaya, Tomohito; Tamura, Kenichi

    2015-09-01

    The rapid accumulation of pre-existing mutations may play major roles in the establishment and shaping of adaptability for local regions in current rice breeding programs. The cultivated rice, Oryza sativa L., which originated from tropical regions, is now grown worldwide due to the concerted efforts of breeding programs. However, the process of establishing local populations and their origins remain unclear. In the present study, we characterized DNA polymorphisms in the rice variety KITAAKE from Hokkaido, one of the northern limits of rice cultivation in the world. Indel polymorphisms were attributed to transposable element-like insertions, tandem duplications, and non-TE deletions as the original mutation events in the NIPPONBARE and KITAAKE genomes. The allele frequencies of the KITAAKE alleles markedly shifted to the current variety types among the local population from Hokkaido in the last two decades. The KITAAKE alleles widely distributed throughout wild rice and cultivated rice over the world. These have accumulated in the local population from Hokkaido via Japanese landraces as the ancestral population of Hokkaido. These results strongly suggested that combinations of pre-existing mutations played a role in the establishment of adaptability. This approach using the re-sequencing of local varieties in unique environmental conditions will be useful as a genetic resource in plant breeding programs in local regions. PMID:26021294

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Ethnobotanical investigation of 'wild' food plants used by rice farmers in Kalasin, Northeast Thailand

    PubMed Central

    2011-01-01

    Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as agricultural areas rather than pristine ecosystems. This paper provides selected results from a study of wild food conducted in several villages in Northeast Thailand. A complete botanical inventory of wild food plants from these communities and surrounding areas is provided including their diversity of growth forms, the different anthropogenic locations were these species grow and the multiplicity of uses they have. Methods Data was collected using focus groups and key informant interviews with women locally recognized as knowledgeable about contemporarily gathered plants. Plant species were identified by local taxonomists. Results A total of 87 wild food plants, belonging to 47 families were reported, mainly trees, herbs (terrestrial and aquatic) and climbers. Rice fields constitute the most important growth location where 70% of the plants are found, followed by secondary woody areas and home gardens. The majority of species (80%) can be found in multiple growth locations, which is partly explained by villagers moving selected species from one place to another and engaging in different degrees of management. Wild food plants have multiple edible parts varying from reproductive structures to vegetative organs. More than two thirds of species are reported as having diverse additional uses and more than half of them are also regarded as medicine. Conclusions This study shows the remarkable importance of anthropogenic areas in providing wild food plants. This is reflected in the great diversity of species found, contributing to the food and nutritional security of rice farmers in Northeast Thailand. PMID:22067578

  15. Energy from rice residues

    SciTech Connect

    Mahin, D.B.

    1990-03-01

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

  16. Inorganic arsenic in rice-based products for infants and young children.

    PubMed

    Signes-Pastor, Antonio J; Carey, Manus; Meharg, Andrew A

    2016-01-15

    Inorganic arsenic (Asi) is a chronic, non-threshold carcinogen. Rice and rice-based products can be the major source of Asi for many subpopulations. Baby rice, rice cereals and rice crackers are widely used to feed infants and young children. The Asi concentration in rice-based products may pose a health risk for infants and young children. Asi concentration was determined in rice-based products produced in the European Union and risk assessment associated with the consumption of these products by infants and young children, and compared to an identical US FDA survey. There are currently no European Union or United States of America regulations applicable to Asi in food. However, this study suggests that the samples evaluated may introduce significant concentration of Asi into infants' and young children's diets. Thus, there is an urgent need for regulatory limits on Asi in food, especially for baby rice-based products. PMID:26258711

  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. 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

  19. [N2O and CH4 emission from Japan rice fields under different long-term fertilization patterns and its environmental impact].

    PubMed

    Luo, Liang-guo; Kondo, Motohiko; Itoh, Sumio

    2010-12-01

    This study intended to investigate the greenhouse gases emission from Japan single cropping paddy fields after 75-year continuous application of ammonium sulfate, composted rice straw with soybean cake, and fresh clover, as well as the environmental impact of the emission. During this long period, field management remained constant in terms of rice cultivation density, irrigation, and equivalent net N fertilization. No significant differences were observed in N2O emission among the fertilization treatments, but the CH4 emission differed significantly between organic amendment and ammonium sulfate application, indicating that long-term organic fertilization didn' t increase N2O emission but promoted CH4 emission. The cumulative global warming potential (GWP) of the CH4 and NO2O from the paddy ecosystem was the greatest (310.7 g CO2e x m(-2)) under fresh clover application, followed by composted rice straw plus soybean cake addition (151 g CO2e x m(-2)), and the least (60.6 g CO2e x m(-2)) under ammonium sulfate application. This study showed that for paddy system, it was CH4 instead of N2O the major factor affecting global warming, and thereby, to control and reduce the CH4 emission from paddy system would be the core in mitigating greenhouse gases emission from paddy field. Long-term consecutive application of composted rice straw plus soybean cake could increase soil organic matter, improve soil fertility, promote rice high-yielding, and as well, mitigate CH4 emission, being the recommendable paddy rice production mode in practice. PMID:21443009

  20. Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-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, γ-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 γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice. PMID:24804068

  1. Trophic cascades across ecosystems.

    PubMed

    Knight, Tiffany M; McCoy, Michael W; Chase, Jonathan M; McCoy, Krista A; Holt, Robert D

    2005-10-01

    Predation can be intense, creating strong direct and indirect effects throughout food webs. In addition, ecologists increasingly recognize that fluxes of organisms across ecosystem boundaries can have major consequences for community dynamics. Species with complex life histories often shift habitats during their life cycles and provide potent conduits coupling ecosystems. Thus, local interactions that affect predator abundance in one ecosystem (for example a larval habitat) may have reverberating effects in another (for example an adult habitat). Here we show that fish indirectly facilitate terrestrial plant reproduction through cascading trophic interactions across ecosystem boundaries. Fish reduce larval dragonfly abundances in ponds, leading to fewer adult dragonflies nearby. Adult dragonflies consume insect pollinators and alter their foraging behaviour. As a result, plants near ponds with fish receive more pollinator visits and are less pollen limited than plants near fish-free ponds. Our results confirm that strong species interactions can reverberate across ecosystems, and emphasize the importance of landscape-level processes in driving local species interactions. PMID:16208370

  2. 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

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

    2010-08-01

    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 microM 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'. PMID:20390245

  3. Heavy metals in Australian grown and imported rice and vegetables on sale in Australia: health hazard.

    PubMed

    Rahman, M Azizur; Rahman, Mohammad Mahmudur; Reichman, Suzie M; Lim, Richard P; Naidu, Ravi

    2014-02-01

    Dietary exposure to heavy metals is a matter of concern for human health risk through the consumption of rice, vegetables and other major foodstuffs. In the present study, we investigated concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in Australian grown and imported rice and vegetables on sale in Australia. The mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in Australian grown rice were 7.5 µg kg(-1), 21 µg kg(-1), 144 µg kg(-1), 2.9 mg kg(-1), 24.4 mg kg(-1), 166 µg kg(-1), 375 µg kg(-1), and 17.1 mg kg(-1) dry weight (d. wt.), respectively. Except Cd, heavy metal concentrations in Australian grown rice were higher than Bangladeshi rice on sale in Australia. However, the concentrations of Cd, Cr, Cu, and Ni in Indian rice on sale in Australia were higher than Australian grown rice. The concentrations of Cu and Ni in Vietnamese rice, and that of Cd, Cr, Cu, Ni, and Pb in Thai rice on sale in Australia were also higher than Australian grown rice. Heavy metal concentrations in Pakistani rice on sale in Australia were substantially lower than that in Australian grown rice. In Australian grown rice varieties, the concentrations of heavy metals were considerably higher in brown rice varieties than white rice varieties, indicating Australian brown rice as a potential source of dietary heavy metals for Australian consumers. The mean concentrations of heavy metals in Australian grown and Bangladeshi vegetables on sale in Australia were also determined. Some of the Australian grown and Bangladeshi vegetables contained heavy metals higher than Australian standard maximum limits indicating them as potential sources of dietary heavy metals for Australian consumers. Further investigation is required to estimate health risks of heavy metals from rice and vegetables consumption for Australian consumers. PMID:24433791

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. 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

  6. 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

  7. Phospholipids in rice: significance in grain quality and health benefits: a review.

    PubMed

    Liu, Lei; Waters, Daniel L E; Rose, Terry J; Bao, Jinsong; King, Graham J

    2013-08-15

    Phospholipids (PLs) are a major class of lipid in rice grain. Although PLs are only a minor nutrient compared to starch and protein, they may have both nutritional and functional significance. We have systemically reviewed the literature on the class, distribution and variation of PLs in rice, their relation to rice end-use quality and human health, as well as available methods for analytical profiling. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and their lyso forms are the major PLs in rice. The deterioration of PC in rice bran during storage was considered as a trigger for the degradation of rice lipids with associated rancid flavour in paddy and brown rice. The lyso forms in rice endosperm represent the major starch lipid, and may form inclusion complexes with amylose, affecting the physicochemical properties and digestibility of starch, and hence its cooking and eating quality. Dietary PLs have a positive impact on several human diseases and reduce the side-effects of some drugs. As rice has long been consumed as a staple food in many Asian countries, rice PLs may have significant health benefits for those populations. Rice PLs may be influenced both by genetic (G) and environmental (E) factors, and resolving G×E interactions may allow future exploitation of PL composition and content, thus boosting rice eating quality and health benefits for consumers. We have identified and summarised the different methods used for rice PL analysis, and discussed the consequences of variation in reported PL values due to inconsistencies between methods. This review enhances the understanding of the nature and importance of PLs in rice and outlines potential approaches for manipulating PLs to improve the quality of rice grain and other cereals. PMID:23561219

  8. Making rice even healthier!

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. 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...

  10. 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...

  11. Registration of 'Medark' Rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  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. 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...

  14. Kernel elongation in rice.

    PubMed

    Golam, Faruq; Prodhan, Zakaria H

    2013-02-01

    Kernel elongation after cooking is an important character of fine rice and most rice consumers prefer length-wise elongation. Although improvement of aromatic rice began early in the 1970s, until now the mechanisms and genetics of kernel elongation has remained unrevealed. Kernel elongation is considered as a physical phenomenon and is influenced by several physicochemical and genetic factors, including genotypes, aging temperature, aging time, water uptake, amylose content and gelatinization temperature. Recently the complete genetic map of fine rice has been created and the gene responsible for kernel length identified; moreover, this gene is tightly linked with the cooked kernel elongation trait. Several molecular markers linked with cooked kernel elongation have been developed. These tools will be helpful for the improvement of this important trait. For the proper study of cooked kernel elongation of rice, this review paper will provide the basis and directional materials for further studies. PMID:23238771

  15. 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 μM 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

  16. The LANSCE RICE control system upgrade.

    SciTech Connect

    Oothoudt, Michael; Schaller, S.; Bjorklund, E. A.; Burns, M. J.; Carr, G.; Carr, G.; Faucett, John Allen,; Hayden, D. J.; Lusk, M. D.; Merl, R. B.; Potter, J. M.; Reynolds, J. A.; Romero, D. B.; Shelley, F. E.

    2003-01-01

    The LANSCE (Los Alamos Neutron Science Center) control system upgrade program continues with the impending replacement of the RICE (Remote Instrumentation and Control Equipment) subsystem. The RICE subsystem upgrade is a challenge because of its technology (late 1960s), number of channels (>10,000), and unique characteristics (all-modules data takes, timed/flavored data takes). The plan is to replace at least the non-timed data and the command portions of the subsystem with Programmable Logic Controllers (PLCs). We discuss motivations, technological challenges, proof-of-principle, and planning. The boundary condition, as usual, is that we must implement these major changes on a running accelerator.

  17. Sulfur Fertilization Changes the Community Structure of Rice Root-, and Soil- Associated Bacteria

    PubMed Central

    Masuda, Sachiko; Bao, Zhihua; Okubo, Takashi; Sasaki, Kazuhiro; Ikeda, Seishi; Shinoda, Ryo; Anda, Mizue; Kondo, Ryuji; Mori, Yumi; Minamisawa, Kiwamu

    2016-01-01

    Under paddy field conditions, biological sulfur oxidation occurs in the oxidized surface soil layer and rhizosphere, in which oxygen leaks from the aerenchyma system of rice plants. In the present study, we examined community shifts in sulfur-oxidizing bacteria associated with the oxidized surface soil layer and rice roots under different sulfur fertilization conditions based on the 16S ribosomal RNA (rRNA) gene in order to explore the existence of oligotrophic sulfur-oxidizing bacteria in the paddy rice ecosystem. Rice plants were grown in pots with no fertilization (control) or CaCO3 or CaSO4 fertilization. A principal-coordinates analysis (PCoA) showed that CaSO4 fertilization markedly affected bacterial communities associated with rice roots and soil, whereas no significant differences were observed in plant growth among the fertilizer treatments examined. In rice roots, the relative abundance of Acidobacteria, Alphaproteobacteria, Gammaproteobacteria, and TM7 was significantly higher in CaSO4-fertilized pots than in control pots. Alphaproteobacteria, Bradyrhizobiaceae, and Methylocystaceae members were significantly more abundant in CaSO4-fertilized roots than in control roots. On the other hand, the abundance of Actinobacteria and Proteobacteria was lower in CaSO4-fertilized soil than in control soil. These results indicate that the bacteria associated with rice roots and soil responded to the sulfur amendment, suggesting that more diverse bacteria are involved in sulfur oxidation in the rice paddy ecosystem than previously considered. PMID:26947443

  18. Sulfur Fertilization Changes the Community Structure of Rice Root-, and Soil- Associated Bacteria.

    PubMed

    Masuda, Sachiko; Bao, Zhihua; Okubo, Takashi; Sasaki, Kazuhiro; Ikeda, Seishi; Shinoda, Ryo; Anda, Mizue; Kondo, Ryuji; Mori, Yumi; Minamisawa, Kiwamu

    2016-03-26

    Under paddy field conditions, biological sulfur oxidation occurs in the oxidized surface soil layer and rhizosphere, in which oxygen leaks from the aerenchyma system of rice plants. In the present study, we examined community shifts in sulfur-oxidizing bacteria associated with the oxidized surface soil layer and rice roots under different sulfur fertilization conditions based on the 16S ribosomal RNA (rRNA) gene in order to explore the existence of oligotrophic sulfur-oxidizing bacteria in the paddy rice ecosystem. Rice plants were grown in pots with no fertilization (control) or CaCO3 or CaSO4 fertilization. A principal-coordinates analysis (PCoA) showed that CaSO4 fertilization markedly affected bacterial communities associated with rice roots and soil, whereas no significant differences were observed in plant growth among the fertilizer treatments examined. In rice roots, the relative abundance of Acidobacteria, Alphaproteobacteria, Gammaproteobacteria, and TM7 was significantly higher in CaSO4-fertilized pots than in control pots. Alphaproteobacteria, Bradyrhizobiaceae, and Methylocystaceae members were significantly more abundant in CaSO4-fertilized roots than in control roots. On the other hand, the abundance of Actinobacteria and Proteobacteria was lower in CaSO4-fertilized soil than in control soil. These results indicate that the bacteria associated with rice roots and soil responded to the sulfur amendment, suggesting that more diverse bacteria are involved in sulfur oxidation in the rice paddy ecosystem than previously considered. PMID:26947443

  19. 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

  20. 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 19802009 at IRRI, Los Baos, 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

  1. Identification of blast resistance genes in rice wild relatives (Oryza spp.) and selected indica lines (o. sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blast, Pyricularia grisea Cav., is a major fungal disease of US cultivated rice (Oryza sativa L.). Blast resistance was observed in some wild relatives of rice (Oryza spp.) and selected indica rice (O. sativa) accessions, indicating these are possible sources of unique blast resistance genes (Pi-ge...

  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. 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...

  4. Temporal interactions of plant - insect - predator after infection of bacterial pathogen on rice plants

    PubMed Central

    Sun, Ze; Liu, Zhuang; Zhou, Wen; Jin, Huanan; Liu, Hao; Zhou, Aiming; Zhang, Aijun; Wang, Man-Qun

    2016-01-01

    Pathogenic infection on plants may affect interactions of host-plants with their herbivores, as well as the herbivores with their predators. In this study, the effects of infection by pathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo), which causes a vascular disease in rice, on rice plants and consequent interactions with a rice herbivore, brown rice planthopper (BPH) Nilaparvata lugens, and its major predator, Cyrtorhinus lividipennis, were investigated. The results showed that the rice plants exhibited increased resistance to BPH only at 3 d post-inoculation of Xoo, while the Xoo infection did not affect the development and fecundity of BPH. BPH exhibited a higher preference to Xoo infected rice plants, whereas C. lividipennis preferred the Xoo infected rice plants after BPH fed, but preferred healthy rice plants without BPH fed. Volatile organic compounds emitted from Xoo rice were significantly higher than those from healthy rice plants, Xoo infection on BPH fed plants caused rice plants to emit more the herbivore-induced plant volatiles, while all of these changes correlated to the temporal dimension. These results demonstrated that Xoo infection significantly influenced the interactions of rice plants with two non-vectors, BPH and its predator, although these effects exhibited in a temporal pattern after infection. PMID:27185548

  5. Functional diversity of jasmonates in rice.

    PubMed

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

    2015-12-01

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

  6. Physical and thermochemical properties of rice husk

    SciTech Connect

    Mansaray, K.G.; Ghaly, A.E.

    1997-11-01

    Rice husk a major by-product of the rice milling industry, is one of the most commonly available lignocellulosic materials that can be converted to different types of fuels and chemical feedstocks through a variety of thermochemical conversion processes. Proper understanding of the physical and thermochemical properties of rice husk is necessary for the design of thermochemical conversion systems. This study provides information on moisture content, bulk density, particle size, heating values, proximate analysis, ultimate analysis, ash composition, and ash fusibility characteristics for six rice husk varieties. The moisture content ranged from 8.68 to 10.44%, and the bulk density ranged from 86 to 114 kg/m{sup 3}. The results showed excessive volatile release of over 60%, high ash content ranging from 15.30 to 24.60% (dry weight basis), and high silica content of the ash ranging from 90 to 97%. The lower heating values ranged from 13.24 to 16.20 MJ/kg (dry weight basis). The ash fusion temperatures of all the varieties were found to be over 1,600 C. The differences in varietal characteristics have significant effects on the chemical properties of rice husk.

  7. Factors affecting methane emission from rice fields

    NASA Astrophysics Data System (ADS)

    Neue, H. U.; Wassmann, R.; Lantin, R. S.; Alberto, Ma C. R.; Aduna, J. B.; Javellana, A. M.

    Emission of CH 4 from ricefields is the result of anoxic bacterial methane production. Global estimates of annual CH 4 emission from ricefields is 100 Tg. CH 4 emission data from limited sites are tentative. It is essential that uncertainty in individual sources is reduced in order to develop feasible and effective mitigation options which do not negate gains in rice production and productivity. Field studies at the International Rice Research Institute show that soil and added organic matter are the sources for initial methane production. Addition of rice straw enhances methane production. Roots and root exudates of wetland rice plants appear to be the major carbon sources at ripening stage. The production and transport of CH 4 to the atmosphere depend on properties of the rice plant. Under the same spacing and fertilization, the traditional variety Dular emitted more CH 4 per day than did the new plant type IR65597. Upon flooding for land preparation anaerobic conditions result in significant amount of methane being formed. Drying the field at midtillering significantly reduced total CH 4 emissions. Large amounts of entrapped CH 4 escape to the atmosphere when floodwater recedes upon drying at harvest. Cultural practices may account for 20% of the overall seasonal CH 4 emissions.

  8. The rice mitochondria proteome and its response during development and to the environment

    PubMed Central

    Huang, Shaobai; Shingaki-Wells, Rachel N.; Taylor, Nicolas L.; Millar, A. Harvey

    2013-01-01

    Rice (Oryza sativa L.) is both a major crop species and the key model grass for molecular and physiological research. Mitochondria are important in rice, as in all crops, as the main source of ATP for cell maintenance and growth. However, the practical significance of understanding the function of mitochondria in rice is increased by the widespread farming practice of using hybrids to boost rice production. This relies on cytoplasmic male sterile (CMS) lines with abortive pollen caused by dysfunctional mitochondria. We provide an overview of what is known about the mitochondrial proteome of rice seedlings. To date, more than 320 proteins have been identified in purified rice mitochondria using mass spectrometry. The insights from this work include a broad understanding of the major subunits of mitochondrial respiratory complexes and TCA cycle enzymes, carbon and nitrogen metabolism enzymes as well as details of the supporting machinery for biogenesis and the subset of stress-responsive mitochondrial proteins. Many proteins with unknown functions have also been found in rice mitochondria. Proteomic analysis has also revealed the features of rice mitochondrial protein presequences required for mitochondrial targeting, as well as cleavage site features for processing of precursors after import. Changes in the abundance of rice mitochondrial proteins in response to different stresses, especially anoxia and light, are summarized. Future research on quantitative analysis of the rice mitochondrial proteomes at the spatial and developmental level, its response to environmental stresses and recent advances in understanding of the basis of rice CMS systems are highlighted. PMID:23403394

  9. Biofortification of rice with lysine using endogenous histones.

    PubMed

    Wong, H W; Liu, Q; Sun, S S M

    2015-02-01

    Rice is the most consumed cereal grain in the world, but deficient in the essential amino acid lysine. Therefore, people in developing countries with limited food diversity who rely on rice as their major food source may suffer from malnutrition. Biofortification of stable crops by genetic engineering provides a fast and sustainable method to solve this problem. In this study, two endogenous rice lysine-rich histone proteins, RLRH1 and RLRH2, were over-expressed in rice seeds to achieve lysine biofortification. Their protein sequences passed an allergic sequence-based homology test. Their accumulations in rice seeds were raised to a moderate level by the use of a modified rice glutelin 1 promoter with lowered expression strength to avoid the occurrence of physiological abnormalities like unfolded protein response. The expressed proteins were further targeted to protein storage vacuoles for stable storage using a glutelin 1 signal peptide. The lysine content in the transgenic rice seeds was enhanced by up to 35%, while other essential amino acids remained balanced, meeting the nutritional standards of the World Health Organization. No obvious unfolded protein response was detected. Different degrees of chalkiness, however, were detected in the transgenic seeds, and were positively correlated with both the levels of accumulated protein and lysine enhancement. This study offered a solution to the lysine deficiency in rice, while at the same time addressing concerns about food safety and physiological abnormalities in biofortified crops. PMID:25512028

  10. 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.

  11. The short and the long of it: SD1 polymorphism and the evolution of growth trait divergence in U.S. weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth related traits are thought to enhance competitiveness of agricultural weeds. U.S. weedy rice, a major conspecific weed of cultivated rice (Oryza sativa), displays variation for growth traits. Prior studies have shown that major U.S. weedy rice populations likely evolved from domesticated grou...

  12. 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 Central

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

    2013-01-01

    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

  13. Evaluation of Environmental Quality Productive Ecosystem Guayas (Ecuador).

    NASA Astrophysics Data System (ADS)

    Pozo, Wilson; Pardo, Francisco; Sanfeliu, Teófilo; Carrera, Gloria; Jordan, Manuel; Bech, Jaume; Roca, Núria

    2015-04-01

    Natural resources are deteriorating very rapidly in the Gulf of Guayaquil and the area of influence in the Guayas Basin due to human activity. Specific problems are generated by the mismanagement of the aquaculture industry affecting the traditional agricultural sectors: rice, banana, sugarcane, cocoa, coffee, and soya also studied, and by human and industrial settlements. The development of industrial activities such as aquaculture (shrimp building for shrimp farming in ponds) and agriculture, have increasingly contributed to the generation of waste, degrading and potentially toxic elements in high concentrations, which can have adverse effects on organisms in the ecosystems, in the health of the population and damage the ecological and environmental balance. The productive Guayas ecosystem, consists of three interrelated ecosystems, the Gulf of Guayaquil, the Guayas River estuary and the Guayas Basin buffer. The objective of this study was to evaluate the environmental quality of the productive Guayas ecosystem (Ecuador), through operational and specific objectives: 1) Draw up the transition coastal zone in the Gulf of Guayaquil, 2) Set temporal spatial variability of soil salinity in wetlands rice, Lower Guayas Basin, 3) evaluate the heavy metals in wetland rice in the Lower Basin of Guayas. The physical and chemical parameters of the soils have been studied. These are indicators of environmental quality. The multivariate statistical method showed the relations of similarities and dissimilarities between variables and parameter studies as stable. Moreover, the boundaries of coastal transition areas, temporal spatial variability of soil salinity and heavy metals in rice cultivation in the Lower Basin of Guayas were researched. The sequential studies included and discussed represent a broad framework of fundamental issues that has been valued as a basic component of the productive Guayas ecosystem. They are determinants of the environmental quality of the Guayas productive ecosystem. Keyword: Evaluation, Environmental Quality, Productive Ecosystem

  14. Developing rice mapping populations as a genetic resource for validation of GWAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian rice (Oryza sativa L.) is divided into two major subspecies, Indica and Japonica with the temperate and tropical japonica subpopulations being part of Japonica. These two subpopulations encompass the majority of the rice grown in the USA. Recently, a genome-wide association study (GWAS) iden...

  15. Soil respiration, labile carbon pools, and enzyme activities as affected by tillage practices in a tropical rice-maize-cowpea cropping system.

    PubMed

    Neogi, S; Bhattacharyya, P; Roy, K S; Panda, B B; Nayak, A K; Rao, K S; Manna, M C

    2014-07-01

    In order to identify the viable option of tillage practices in rice-maize-cowpea cropping system that could cut down soil carbon dioxide (CO2) emission, sustain grain yield, and maintain better soil quality in tropical low land rice ecology soil respiration in terms of CO2 emission, labile carbon (C) pools, water-stable aggregate C fractions, and enzymatic activities were investigated in a sandy clay loam soil. Soil respiration is the major pathway of gaseous C efflux from terrestrial systems and acts as an important index of ecosystem functioning. The CO2-C emissions were quantified in between plants and rows throughout the year in rice-maize-cowpea cropping sequence both under conventional tillage (CT) and minimum tillage (MT) practices along with soil moisture and temperature. The CO2-C emissions, as a whole, were 24 % higher in between plants than in rows, and were in the range of 23.4-78.1, 37.1-128.1, and 28.6-101.2 mg m(-2) h(-1) under CT and 10.7-60.3, 17.3-99.1, and 17.2-79.1 mg m(-2) h(-1) under MT in rice, maize, and cowpea, respectively. The CO2-C emission was found highest under maize (44 %) followed by rice (33 %) and cowpea (23 %) irrespective of CT and MT practices. In CT system, the CO2-C emission increased significantly by 37.1 % with respect to MT on cumulative annual basis including fallow. The CO2-C emission per unit yield was at par in rice and cowpea signifying the beneficial effect of MT in maintaining soil quality and reduction of CO2 emission. The microbial biomass C (MBC), readily mineralizable C (RMC), water-soluble C (WSC), and permanganate-oxidizable C (PMOC) were 19.4, 20.4, 39.5, and 15.1 % higher under MT than CT. The C contents in soil aggregate fraction were significantly higher in MT than CT. Soil enzymatic activities like, dehydrogenase, fluorescein diacetate, and β-glucosidase were significantly higher by 13.8, 15.4, and 27.4 % under MT compared to CT. The soil labile C pools, enzymatic activities, and heterotrophic microbial populations were in the order of maize > cowpea > rice, irrespective of the tillage treatments. Environmental sustainability point of view, minimum tillage practices in rice-maize-cowpea cropping system in tropical low land soil could be adopted to minimize CO2-C emission, sustain yield, and maintain soil health. PMID:24609455

  16. Impacts of climate change on rice yield: A comparison of four model performances

    SciTech Connect

    Bachelet, D.; Gay, C.A.

    1993-01-01

    Increasing concentrations of carbon dioxide (CO2) and other greenhouse gases are expected to modify temperature and rainfall the next 50-100 years. Mechanisms and hypotheses of plant response to these changes could be incorporated in models predicting crop yield estimates to better understand potential consequences of such changes. Asia is particularly important since demographic forecasts indicate rice supplies worldwide will need to increase by 1.6% annually to the year 2000 to match population growth estimates. The objectives of the paper are (1) review the major hypotheses and/or experimental results regarding rice sensitivity to climate change and (2) evaluate the suitability of existing rice models for assessing the impact of global climate change on rice production. A review of four physiologically-based rice models (RICEMOD, CERES-Rice, MACROS, RICESYS) illustrates their potential to predict rice responses to elevated CO2 and increased temperature.

  17. 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

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

    PubMed

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

    2013-01-01

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

  19. Monitoring rice cropping systems using China environment satellite data in Poyang Lake region

    NASA Astrophysics Data System (ADS)

    Li, Peng; Jiang, Luguang; Feng, Zhiming

    Threshold method was utilized to discriminate rice cropping systems based on the noticeable variation of Normalized Difference Vegetation Index (NDVI) during key growth stages in Poyang Lake Region, China. This area is dominated by double- and single rice cropping systems which tend to change due to the frequent ecosystem management policies. We used a new satellite data from the CCD camera sensor with 30 m spatial resolution onboard the China Environmental Satellite HJ-1A and B. The HJ -1A/B with a better temporal resolution of four days provides more data options for effective and timely agriculture monitoring. The result showed that there is evident difference of NDVI between single and late rice during mid October when they are in different growth stages. The areas of single and late rice in 2011 were 2988.6 km2 and 3105.9 km2, respectively. Paddy field distribution map and local paddy rice calendar are requisite to move the threshold method into other multiple rice cropping regions. The study suggests that the China Environmental Satellite HJ-1A/B have the potential to rice cropping system in the double to triple rice cropping systems area. With many advantages of HJ-1A/B, like, finer spatial and temporal resolution, bigger imaging swath, it may make rice cropping system monitoring more feasible and operational.

  20. 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

  1. Northward expansion of paddy rice in northeastern Asia during 2000-2014

    NASA Astrophysics Data System (ADS)

    Dong, J.; Xiao, X.; Zhang, G.; Menarguez, M. A.; Choi, C. Y.; Qin, Y.; Luo, P.; Zhang, Y.; Moore, B.

    2016-04-01

    Paddy rice in monsoon Asia plays an important role in global food security and climate change. Here we documented annual dynamics of paddy rice areas in the northern frontier of Asia, including northeastern (NE) China, North Korea, South Korea, and Japan, from 2000 to 2014 through analysis of satellite images. The paddy rice area has increased by 120% (2.5 to 5.5 million ha) in NE China, in comparison to a decrease in South Korea and Japan, and the paddy rice centroid shifted northward from 41.16°N to 43.70°N (~310 km) in this period. Market, technology, policy, and climate together drove the rice expansion in NE China. The increased use of greenhouse nurseries, improved rice cultivars, agricultural subsidy policy, and a rising rice price generally promoted northward paddy rice expansion. The potential effects of large rice expansion on climate change and ecosystem services should be paid more attention to in the future.

  2. 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.

  3. Population structure of putative rice-red rice hybrid derivatives in the Southern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice and red rice can readily intercross in southern U.S. rice fields, however, the extent to which progeny of these rice-red rice hybrids may have successfully moved into red rice populations is unknown. Approximately 430 red rice accessions were obtained from farm samples in 1999 and 2000. Forty...

  4. 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 ...

  5. Characterization of rice blast resistance genes in rice germplasm with monogenic lines and pathogenicity assays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance (R) genes have been effectively deployed in preventing rice crop losses due to the fungus Magnaporthe oryzae. In the present study, we studied the interaction between 24 monogenic lines carrying at least one major R gene, Pia, Pib, Pii, Pik, Pik-h, Pik-m, Pik-p, Pik-s, Pish, Pit, Pita, Pi...

  6. Genome-wide association of rice blast disease resistance and yield-related components of rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Robust disease resistance may require an expenditure of energy that may limit crop yield potential. In the present study, a subset of a USDA rice core collection consisting of 151 accessions was selected using a major blast resistance (R) gene Pi-ta marker, and was genotyped with 156 simple sequence...

  7. QTL analysis of internode elongation in response to gibberellin in deepwater rice

    PubMed Central

    Nagai, Keisuke; Kondo, Yuma; Kitaoka, Takuya; Noda, Tomonori; Kuroha, Takeshi; Angeles-Shim, Rosalyn B.; Yasui, Hideshi; Yoshimura, Atsushi; Ashikari, Motoyuki

    2014-01-01

    Gibberellin (GA) is a plant hormone that has important roles in numerous plant developmental phases. Rice plants known as deepwater rice respond to flooding by elongating their internodes to avoid anoxia. Previous studies reported that GA is essential for internode elongation in deepwater rice. Quantitative trait locus (QTL) analyses identified QTLs regulating internode elongation in response to deepwater conditions. However, the interaction between internode elongation and regulators of GA sensitivity in deepwater rice is unknown. In this study, we applied GA to recombinant inbred lines of T65 (non-deepwater rice) and Bhadua (deepwater rice), and performed a QTL analysis of internode elongation in response to GA. GA-induced internode elongation was detected only in deepwater rice. Our QTL analysis revealed two major QTLs on chromosomes 3 and 9 regulating total internode length, lowest elongated internode and number of elongated internodes. Furthermore, the QTL on chromosome 3 acted as an enhancer of other QTLs (e.g. the QTL on chromosome 12). Nearly isogenic lines of deepwater rice carrying the QTL regions from chromosomes 3 and 12 of the deepwater rice C9285 showed internode elongation in response to GA. Thus, these QTLs may regulate GA responsiveness in deepwater rice. This study furthers our understanding of the mechanism of internode elongation in rice. PMID:24946943

  8. Cadmium content in rice and its daily intake in various countries

    SciTech Connect

    Rivai, Ida Farida; Koyama, Hiroshi; Suzuki, Shosuke )

    1990-06-01

    Man ingests cadmium daily from foods and beverages. The major source of cadmium intake is rice for rice eating countries. Cadmium in rice comes from soil via rice plant roots. Rice may thus be the best indicator for the environmental monitoring of cadmium especially in rice eating countries. It is also easy to sample, transport and conserve. Several recent surveys on cadmium content in rice and daily cadmium intake have been reported. However, little data are available on geographical differences in daily cadmium intake from rice. The tolerable weekly intake for cadmium as proposed by FAO/WHO is 400-500 micrograms/person or 57-71 micrograms/day/person weighing 70 kg. Ninety two percent of world rice production is from the Asia-Pacific region, from which samples were obtained for the present study. The following countries were included: India, China, Bangladesh, Thailand, Indonesia, Philippines, Japan, and Korea. This study was conducted to determine cadmium content in rice from the above countries and based on the data obtained, daily cadmium intake from rice and the total daily cadmium intake were calculated.

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  10. 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.

  11. Competitive N uptake between rice and weedy rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weedy rice, red rice (Oryza sativa L.), is a serious problem in rice-producing areas of the southern U.S. and various regions worldwide. It competes for production inputs, increases weed control costs, reduces yield and grain quality, and could eliminate economic returns. Research was conducted to...

  12. Red Yeast Rice: An Introduction

    MedlinePlus

    ... preparations of red yeast rice are used in food products in Chinese cuisine, including Peking duck. Others have been sold as dietary supplements to lower blood levels of cholesterol and related lipids. Some red yeast rice products contain substances called ...

  13. 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

  14. Succession of methanogenic archaea in rice straw incorporated into a Japanese rice field: estimation by PCR-DGGE and sequence analyses.

    PubMed

    Sugano, Atsuo; Tsuchimoto, Hidetaka; Cho, Tun Cho; Kimura, Makoto; Asakawa, Susumu

    2005-12-01

    The succession and phylogenetic profiles of methanogenic archaeal communities associated with rice straw decomposition in rice-field soil were studied by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis followed by 16S rDNA sequencing. Nylon bags containing either leaf sheaths or blades were buried in the plowed layer of a Japanese rice field under drained conditions during the off-crop season and under flooded conditions after transplanting. In addition, rice straw samples that had been buried in the rice field under drained conditions during the off-crop season were temporarily removed during spring plowing and then re-buried in the same rice field under flooded conditions at transplanting. Populations of methanogenic archaea were examined by amplification of the 16S rRNA genes in the DNA extracted from the rice straw samples. No PCR product was produced for samples of leaf sheath or blade prior to burial or after burial under drained conditions, indicating that the methanogen population was very small during decomposition of rice straw under oxic conditions. Many common bands were observed in rice straw samples of leaf sheath and blade during decomposition of rice straw under flooded conditions. Cluster analysis based on DGGE patterns divided methanogenic archaeal communities into two groups before and after the mid-season drainage. Sequence analysis of DGGE bands that were commonly present were closely related to Methanomicrobiales and Rice cluster I. Methanomicrobiales, Rice cluster I and Methanosarcinales were major members before the mid-season drainage, whereas the DGGE bands that characterized methanogenic archaeal communities after the mid-season drainage were closely related to Methanomicrobiales. These results indicate that mid-season drainage affected the methanogenic archaeal communities irrespective of their location on rice straw (sheath and blade) and the previous history of decomposition during the off-crop season. PMID:16243779

  15. Major depression

    MedlinePlus

    Depression - major; Depression - clinical; Clinical depression; Unipolar depression; Major depressive disorder ... Doctors do not know the exact causes of depression. It is believed that chemical changes in the ...

  16. Selenium characterization in the global rice supply chain.

    PubMed

    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

    2009-08-01

    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: approximately 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(-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 (micro-XRF) and X-ray absorption near edge structure (micro-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. PMID:19731713

  17. 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.

    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.

  18. Louisiana Coastal Ecosystem

    USGS Publications Warehouse

    U.S. Geological Survey

    2000-01-01

    Louisiana's coast and its degradation and restoration are major environmental issues being studied at the National Wetlands Research Center. Coastal ecosystems are vulnerable because of the tremendous amount of human activity that takes place along the coast. Information on ecological processes is essential to guide the development along the coast as well as to protect and restore wildlife habitat. Louisiana has about 40% of coastal wetlands in the lower 48 states; they support fish, waterfowl, and fur-bearing animals as well as unique cultures like that of the Acadians. The fish and wildlife resources of Louisiana's coast produce over $1 billion each year in revenues. But Louisiana has the highest coastal loss rate because of natural and human causes. Over the past three decades, Louisiana has lost as much as 35-40 mi2 (90-104 km2) of coastal wetlands a year. The National Wetlands Research Center is qualified to assess and monitor this ecosystem because of its proximity to the study area, a staff chosen for their expertise in the system, and a number of established partnerships with others who study the areas. The Center is often the lead group in partnerships with universities, other federal agencies, and private entities who study this ecosystem. Most of the Center's research and technology development performed for coastal wetlands are done at the Lafayette headquarters; some work is performed at the National Wetlands Research Center's project office in Baton Rouge, LA.

  19. 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

  20. Large Aquatic Ecosystem Restoration Monitoring for Decision Makers: Monitoring to Target and Evaluate Success of Ecosystem Restoration

    EPA Science Inventory

    Monitoring ecosystem restoration at various scales in LAEs can be challenging, frustrating and rewarding. Some of the major ecosystem restoration monitoring occurring in LAEs include: seagrass expansion/contraction; dead zone sizes; oyster reefs; sea turtle nesting; toxic and nu...

  1. Rice fortification: an emerging opportunity to contribute to the elimination of vitamin and mineral deficiency worldwide.

    PubMed

    Muthayya, Sumithra; Hall, Jessica; Bagriansky, Jack; Sugimoto, Jonathan; Gundry, Daniel; Matthias, Dipika; Prigge, Shane; Hindle, Peter; Moench-Pfanner, Regina; Maberly, Glen

    2012-12-01

    Vitamin and mineral deficiencies are ranked among the top causes of poor health and disability in the world. These deficiencies damage developing brains, impair learning ability, increase susceptibility to infections, and reduce the work productivity of nations. Food fortification is a sustainable, cost-effective approach to reducing vitamin and mineral deficiency. As the staple food for an estimated 3 billion people, rice has the potential to fill an obvious gap in current fortification programs. In recent years, new technologies have produced fortified rice kernels that are efficacious in reducing vitamin and mineral deficiency. There are opportunities to fortify a significant share of rice that comes from large mills supplying centralized markets and national welfare programs in major rice-growing countries. The rice export markets, which handle 30 million MT of rice annually, also present a key fortification opportunity. The cost of fortifying rice is only 1.5% to 3% of the current retail price of rice. Countries that mandate rice fortification have the strongest evidence for achieving wide coverage and impact. The Rice Fortification Resource Group (RiFoRG), a global network of public and private partners that offers technical and advocacy support for rice fortification, has a vision of promoting rice fortification worldwide. It has a targeted approach, engaging multisector partners in key countries where the opportunities are greatest and there is receptivity to early adoption of large-scale rice fortification. The challenges are real, the imperative to address them is powerful, and the opportunities to deliver the promise of rice fortification are clear. PMID:23424896

  2. Modeling greenhouse gas emissions from rice-based production systems: Sensitivity and upscaling

    NASA Astrophysics Data System (ADS)

    Li, Changsheng; Mosier, Arvin; Wassmann, Reiner; Cai, Zucong; Zheng, Xunhua; Huang, Yao; Tsuruta, Haruo; Boonjawat, Jariya; Lantin, Rhoda

    2004-03-01

    A biogeochemical model, Denitrification-Decomposition (DNDC), was modified to enhance its capacity of predicting greenhouse gas (GHG) emissions from paddy rice ecosystems. The major modifications focused on simulations of anaerobic biogeochemistry and rice growth as well as parameterization of paddy rice management. The new model was tested for its sensitivities to management alternatives and variations in natural conditions including weather and soil properties. The test results indicated that (1) varying management practices could substantially affect carbon dioxide (CO2), methane (CH4), or nitrous oxide (N2O) emissions from rice paddies; (2) soil properties affected the impacts of management alternatives on GHG emissions; and (3) the most sensitive management practices or soil factors varied for different GHGs. For estimating GHG emissions under certain management conditions at regional scale, the spatial heterogeneity of soil properties (e.g., texture, SOC content, pH) are the major source of uncertainty. An approach, the most sensitive factor (MSF) method, was developed for DNDC to bring the uncertainty under control. According to the approach, DNDC was run twice for each grid cell with the maximum and minimum values of the most sensitive soil factors commonly observed in the grid cell. The simulated two fluxes formed a range, which was wide enough to include the "real" flux from the grid cell with a high probability. This approach was verified against a traditional statistical approach, the Monte Carlo analysis, for three selected counties or provinces in China, Thailand, and United States. Comparison between the results from the two methods indicated that 61-99% of the Monte Carlo-produced GHG fluxes were located within the MSA-produced flux ranges. The result implies that the MSF method is feasible and reliable to quantify the uncertainties produced in the upscaling processes. Equipped with the MSF method, DNDC modeled emissions of CO2, CH4, and N2O from all of the rice paddies in China with two different water management practices, i.e., continuous flooding and midseason drainage, which were the dominant practices before 1980 and in 2000, respectively. The modeled results indicated that total CH4 flux from the simulated 30 million ha of Chinese rice fields ranged from 6.4 to 12.0 Tg CH4-C per year under the continuous flooding conditions. With the midseason drainage scenario, the national CH4 flux from rice agriculture reduced to 1.7-7.9 Tg CH4-C. It implied that the water management change in China reduced CH4 fluxes by 4.2-4.7 Tg CH4-C per year. Shifting the water management from continuous flooding to midseason drainage increased N2O fluxes by 0.13-0.20 Tg N2O-N/yr, although CO2 fluxes were only slightly altered. Since N2O possesses a radiative forcing more than 10 times higher than CH4, the increase in N2O offset about 65% of the benefit gained by the decrease in CH4 emissions.

  3. 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

  4. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Development of a microarray for two rice subspecies: characterization and validation of gene expression in rice tissues

    PubMed Central

    2014-01-01

    Background Rice is one of the major crop species in the world helping to sustain approximately half of the global population’s diet especially in Asia. However, due to the impact of extreme climate change and global warming, rice crop production and yields may be adversely affected resulting in a world food crisis. Researchers have been keen to understand the effects of drought, temperature and other environmental stress factors on rice plant growth and development. Gene expression microarray technology represents a key strategy for the identification of genes and their associated expression patterns in response to stress. Here, we report on the development of the rice OneArray® microarray platform which is suitable for two major rice subspecies, japonica and indica. Results The rice OneArray® 60-mer, oligonucleotide microarray consists of a total of 21,179 probes covering 20,806 genes of japonica and 13,683 genes of indica. Through a validation study, total RNA isolated from rice shoots and roots were used for comparison of gene expression profiles via microarray examination. The results were submitted to NCBI’s Gene Expression Omnibus (GEO). Data can be found under the GEO accession number GSE50844 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE50844). A list of significantly differentially expressed genes was generated; 438 shoot-specific genes were identified among 3,138 up-regulated genes, and 463 root-specific genes were found among 3,845 down-regulated genes. GO enrichment analysis demonstrates these results are in agreement with the known physiological processes of the different organs/tissues. Furthermore, qRT-PCR validation was performed on 66 genes, and found to significantly correlate with the microarray results (R = 0.95, p < 0.001***). Conclusion The rice OneArray® 22 K microarray, the first rice microarray, covering both japonica and indica subspecies was designed and validated in a comprehensive study of gene expression in rice tissues. The rice OneArray® microarray platform revealed high specificity and sensitivity. Additional information for the rice OneArray® microarray can be found at http://www.phalanx.com.tw/index.php. PMID:24398116

  7. Long-term effect of rice-based farming systems on soil health.

    PubMed

    Bihari, Priyanka; Nayak, A K; Gautam, Priyanka; Lal, B; Shahid, M; Raja, R; Tripathi, R; Bhattacharyya, P; Panda, B B; Mohanty, S; Rao, K S

    2015-05-01

    Integrated rice-fish culture, an age-old farming system, is a technology which could produce rice and fish sustainably at a time by optimizing scarce resource use through complementary use of land and water. An understanding of microbial processes is important for the management of farming systems as soil microbes are the living part of soil organic matter and play critical roles in soil C and N cycling and ecosystem functioning of farming system. Rice-based integrated farming system model for small and marginal farmers was established in 2001 at Central Rice Research Institute, Cuttack, Odisha. The different enterprises of farming system were rice-fish, fish-fingerlings, fruits, vegetables, rice-fish refuge, and agroforestry. This study was conducted with the objective to assess the soil physicochemical properties, microbial population, carbon and nitrogen fractions, soil enzymatic activity, and productivity of different enterprises. The effect of enterprises induced significant changes in the chemical composition and organic matter which in turn influenced the activities of enzymes (urease, acid, and alkaline phosphatase) involved in the C, N, and P cycles. The different enterprises of long-term rice-based farming system caused significant variations in nutrient content of soil, which was higher in rice-fish refuge followed by rice-fish enterprise. Highest microbial populations and enzymatic properties were recorded in rice-fish refuge system because of waterlogging and reduced condition prolonged in this system leading to less decomposition of organic matter. The maximum alkaline phosphatase, urease, and FDA were observed in rice-fish enterprise. However, highest acid phosphatase and dehydrogenase activity were obtained in vegetable enterprise and fish-fingerlings enterprise, respectively. PMID:25913623

  8. 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…

  9. 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...

  10. 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

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

    PubMed

    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. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community

    PubMed Central

    Schmidt, Anja; John, Katharina; Arida, Gertrudo; Auge, Harald; Brandl, Roland; Horgan, Finbarr G.; Hotes, Stefan; Marquez, Leonardo; Radermacher, Nico; Settele, Josef; Wolters, Volkmar; Schädler, Martin

    2015-01-01

    Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices. PMID:26225556

  13. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

    PubMed

    Schmidt, Anja; John, Katharina; Arida, Gertrudo; Auge, Harald; Brandl, Roland; Horgan, Finbarr G; Hotes, Stefan; Marquez, Leonardo; Radermacher, Nico; Settele, Josef; Wolters, Volkmar; Schädler, Martin

    2015-01-01

    Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices. PMID:26225556

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  16. 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...

  17. 40 CFR Table 1b to Subpart Zzzz of... - Operating Limitations for Existing, New, and Reconstructed Spark Ignition 4SRB Stationary RICE...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., and Reconstructed Spark Ignition 4SRB Stationary RICE >500 HP Located at a Major Source of HAP Emissions and Existing Spark Ignition 4SRB Stationary RICE >500 HP Located at an Area Source of HAP... Limitations for Existing, New, and Reconstructed Spark Ignition 4SRB Stationary RICE >500 HP Located at...

  18. 40 CFR Table 1b to Subpart Zzzz of... - Operating Limitations for Existing, New, and Reconstructed Spark Ignition 4SRB Stationary RICE...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., New, and Reconstructed Spark Ignition 4SRB Stationary RICE >500 HP Located at a Major Source of HAP Emissions and Existing Spark Ignition 4SRB Stationary RICE >500 HP Located at an Area Source of HAP... Limitations for Existing, New, and Reconstructed Spark Ignition 4SRB Stationary RICE >500 HP Located at...

  19. 40 CFR Table 1b to Subpart Zzzz of... - Operating Limitations for Existing, New, and Reconstructed Spark Ignition, 4SRB Stationary RICE...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., New, and Reconstructed Spark Ignition, 4SRB Stationary RICE >500 HP Located at a Major Source of HAP... Limitations for Existing, New, and Reconstructed Spark Ignition, 4SRB Stationary RICE >500 HP Located at a... stationary RICE complying with the requirement to reduce formaldehyde emissions by 76 percent or more (or...

  20. A double built-in containment strategy for production of recombinant proteins in transgenic rice.

    PubMed

    Zhang, Xianwen; Wang, Dongfang; 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

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

    PubMed Central

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

    2010-01-01

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

  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. 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

  4. Volatile components in stored rice [Oryza sativa (L.)] of varieties with and without lipoxygenase-3 in seeds.

    PubMed

    Suzuki, Y; Ise, K; Li, C; Honda, I; Iwai, Y; Matsukura, U

    1999-03-01

    Lipoxygenase (LOX) is thought to play an important role in the formation of desirable or undesirable flavor and aroma in many plant products. In rice seeds, LOX activity is localized in the bran fraction and LOX-3 is the major isozyme component. We used gas chromatography-mass spectrometry to determine whether the degree of staleness in the flavor of stored brown rice was related to the presence of LOX-3. We found that the amount of hexanal, pentanal, and pentanol in normal raw LOX-3 rice markedly increased during storage at 35 degrees C. That in LOX-3-less rice increased slightly but was a third to a fifth that of normal LOX-3 rice. In cooked rice, the amount of these components from glutinous rice exceeded that in nonglutinous rice, and that in normal LOX-3 rice exceeded that in LOX-3-less rice. These results indicate that the stale flavor production in LOX-3-less rice during storage is less than that in normal LOX-3 rice. PMID:10552425

  5. Nitrogen uptake and use efficiency in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. 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 (δ13C-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.

  7. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. 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...

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

    PubMed

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

    2014-05-01

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

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. Cytoplasmic effects on DNA methylation between male sterile line and its maintainer in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybrid rice is advantageous over the traditional one on food production, which is important to support the increasing world’s population, especially in the developing countries. Three-line system that has played a major role since the 1970s in rice includes male sterile (A line), its maintainer (B l...

  16. 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...

  17. Genetic architecture of grain chalk in rice and interactions with a low phytic acid locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain quality characteristics have a major impact on the value of the harvested rice crop. In addition to grain dimensions which determine market classes, translucency is also required for the highest grain quality. Over the last several years, the USA rice industry has been concerned about the incr...

  18. 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...

  19. Arsenic, Organic Foods, and Brown Rice Syrup

    PubMed Central

    Taylor, Vivien F.; Karagas, Margaret R.; Punshon, Tracy; Cottingham, Kathryn L.

    2012-01-01

    Background: Rice can be a major source of inorganic arsenic (Asi) for many sub-populations. Rice products are also used as ingredients in prepared foods, some of which may not be obviously rice based. Organic brown rice syrup (OBRS) is used as a sweetener in organic food products as an alternative to high-fructose corn syrup. We hypothesized that OBRS introduces As into these products. Objective: We determined the concentration and speciation of As in commercially available brown rice syrups and in products containing OBRS, including toddler formula, cereal/energy bars, and high-energy foods used by endurance athletes. Methods: We used inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography coupled to ICP-MS to determine total As (Astotal) concentrations and As speciation in products purchased via the Internet or in stores in the Hanover, New Hampshire, area. Discussion: We found that OBRS can contain high concentrations of Asi and dimethyl-arsenate (DMA). An “organic” toddler milk formula containing OBRS as the primary ingredient had Astotal concentrations up to six times the U.S. Environmental Protection Agency safe drinking water limit. Cereal bars and high-energy foods containing OBRS also had higher As concentrations than equivalent products that did not contain OBRS. Asi was the main As species in most food products tested in this study. Conclusions: There are currently no U.S. regulations applicable to As in food, but our findings suggest that the OBRS products we evaluated may introduce significant concentrations of Asi into an individual’s diet. Thus, we conclude that there is an urgent need for regulatory limits on As in food. PMID:22336149

  20. The rice mitochondrial genomes and their variations.

    PubMed

    Tian, Xiangjun; Zheng, Jing; Hu, Songnian; Yu, Jun

    2006-02-01

    Based on highly redundant and high-quality sequences, we assembled rice (Oryza sativa) mitochondrial genomes for two cultivars, 93-11 (an indica variety) and PA64S (an indica-like variety with maternal origin of japonica), which are paternal and maternal strains of an elite superhybrid rice Liang-You-Pei-Jiu (LYP-9), respectively. Following up with a previous analysis on rice chloroplast genomes, we divided mitochondrial sequence variations into two basic categories, intravarietal and intersubspecific. Intravarietal polymorphisms are variations within mitochondrial genomes of an individual variety. Intersubspecific polymorphisms are variations between subspecies among their major genotypes. In this study, we identified 96 single nucleotide polymorphisms (SNPs), 25 indels, and three segmental sequence variations as intersubspecific polymorphisms. A signature sequence fragment unique to indica varieties was confirmed experimentally and found in two wild rice samples, but absent in japonica varieties. The intersubspecific polymorphism rate for mitochondrial genomes is 0.02% for SNPs and 0.006% for indels, nearly 2.5 and 3 times lower than that of their chloroplast counterparts and 21 and 38 times lower than corresponding rates of the rice nuclear genome, respectively. The intravarietal polymorphism rates among analyzed mitochondrial genomes, such as 93-11 and PA64S, are 1.26% and 1.38% for SNPs and 1.13% and 1.09% for indels, respectively. Based on the total number of SNPs between the two mitochondrial genomes, we estimate that the divergence of indica and japonica mitochondrial genomes occurred approximately 45,000 to 250,000 years ago. PMID:16384910

  1. Gasification of rice husk

    SciTech Connect

    Chen, C.C.; Rei, M.H.

    1981-01-01

    Bench scale experiments with continuous feed of 0.7 kg dry rice husk/hr have been carried out in a 5.0 cm diameter electrically heated fluidized bed reactor, using superheated steam to fluidize fused almina sand. Using the results of the experiments a complete material and energy balance were calculated. 3 refs.

  2. Flooded Wild Rice River

    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....

  3. 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 worlds 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...

  4. Exploring Japan through Rice.

    ERIC Educational Resources Information Center

    Wojtan, Linda S.

    1998-01-01

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

  5. 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...

  6. 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...

  7. Quantitative trait loci analysis for rice seed vigor during the germination stage.

    PubMed

    Wang, Zhou-fei; Wang, Jian-fei; Bao, Yong-mei; Wang, Fu-hua; Zhang, Hong-sheng

    2010-12-01

    Seed vigor is an important characteristic of seed quality, and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment. In the present study, the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage, including germination rate, final germination percentage, and germination index, were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28, and using the multiple interval mapping (MIM) approach. The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice. A total of ten QTLs, and at least five novel alleles, were detected to control rice seed vigor, and the amount of variation (R(2)) explained by an individual QTL ranged from 7.5% to 68.5%, with three major QTLs with R(2)>20%. Most of the QTLs detected here are likely to coincide with QTLs for seed weight, seed size, or seed dormancy, suggesting that the rice seed vigor might be correlated with seed weight, seed size, and seed dormancy. At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice, and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice. PMID:21121075

  8. Arsenic speciation in rice cereals for infants.

    PubMed

    Juskelis, Rima; Li, Wanxing; Nelson, Jenny; Cappozzo, Jack C

    2013-11-13

    The aim of this study was to conduct a survey of arsenic (As) content in rice cereals for infants. The analysis was based on the FDA Elemental Analysis Manual (EAM 4.11). An inductively coupled plasma mass spectrometer (ICP-MS) was used to determine total As. Due to the different toxicities of the chemical forms of arsenic, the ICP-MS coupled to a high-performance liquid chromatograph (HPLC) was used to perform As speciation. The total and speciated arsenic was determined in 31 different infant rice cereals sold in U.S. supermarkets. The mass fraction of total inorganic As (iAs; sum of arsenite As(III) and arsenate As(V)) concentrations ranged between 55.5 ± 1.3 and 158.0 ± 6.0 μg/kg. The average total arsenic and iAs concentrations in infant rice cereal were 174.4 and 101.4 μg/kg, respectively. There was no substantial difference in iAs levels between organic and conventional rice cereals. The mixed-grain rice cereal contained the least total (105 μg/kg) and inorganic arsenic (63 μg/kg). The major detected organoarsenical species was dimethylarsinic acid (DMA). Monomethylarsonic acid (MMA) was not detected, or only trace levels were found. Spiked sample percent recoveries for iAs, DMA, and MMA ranged from a low of 97.3% for iAs to a high of 115.0% for DMA. Results for speciated and total As in the National Institute of Standards and Technology standard reference material rice flour (NIST SRM 1568) were in good agreement with certified values. In the NIST SRM 1568 sample (n = 5) repeatability (%RSD) was 2.8% for iAs, 1.7% for DMA and species sum, and 5.3% for the total arsenic by As total method. The average percent mass balance was 99.9 ± 6.3% for the NIST SRM 1568 sample. This study provides new and much needed information on arsenic levels in rice-based infant cereals. PMID:24079539

  9. [Adsorption-desorption Characteristics of Fermented Rice Husk for Ferrous and Sulfur Ions].

    PubMed

    Xie, Xiao-mei; Liao, Min; Hua, Jia-yuan; Chen, Na; Zhang, Nan; Xu, Pei-zhi; Xie Kai-zhi; XU, Chang-xu; Liu, Guang-rong

    2015-10-01

    To understand the potential of rice husk to fix Fe2+ and S2- ions, the sorption of Fe2+ and S2- by fermented rice husk was studied by using batch incubation experiments in the present study. The effects of adsorption time, Fe2+ and S2- concentration, pH, the temperature and ionic strength in adsorption reaction solution on the sorption were investigated. Therefore, the stability of Fe2+ and S2- adsorbed by fermented rice husk was further validated by desorption experiments performed under similar conditions as adsorption. The results showed that, the adsorption kinetics of Fe2+ (r = 0.912 1) and S2- (r = 0.901 1) by fermented rice husk fits the Elovich kinetics equation, and Freundlich isotherm model could simulate the isotherm adsorption processes of Fe2+ (R2 = 0.965 1) and S2- (R2 = 0.936 6) on fermented rice husk was better than other models. The adsorption processes on fermented rice husk were non- preferential adsorption for Fe2+ and S2, while the adsorption process of Fe2+ on fermented rice husk was spontaneous reaction and the adsorption process of S2- was non-spontaneous reaction. The adsorption processes of Fe2+ and S2- on fermented rice husk were endothermic process since high temperature could benefit to the adsorption. The adsorption mechanism of Fe2+ on fermented rice husk was mainly controlled by coordination adsorption, the adsorption mechanism of S2- on fermented rice husk was mainly controlled by ligand exchange adsorption. The adsorption processes of Fe2+ and S2- on fermented rice husk showed greater pH adaptability which ranged from 1.50 to 11.50. With the increasing of ionic strength, the amount of adsorbed Fe2+ on fermented rice husk wasincreased in some extent, the amount of adsorbed S2- on fermented rice husk was slightly decreased, which further proved the adsorption of Fe2+ was major in inner sphere complexation and the adsorption of S2- was major in outer complexation. The desorption rates of Fe2+ and S2- which was adsorbed by fermented rice husk were lower in different pH or ionic strength conditions, the desorption rates were all below 10 percentage which proved that the adsorption stabilities of Fe2+ and S2- on fermented rice husk were superior. The above results indicated that, the adsorption abilities to Fe2+ and S2- on fermented rice husk were better and had greater environmental adaptability. The Fe2+ and S2- adsorbed by fermented rice husk showed higher stability, and were not easy to release again. PMID:26841629

  10. Rice Glycosyltransferase (GT) Phylogenomic Database

    DOE Data Explorer

    Ronald, Pamela

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

  11. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  12. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  13. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  14. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  15. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  16. Improved determination of daytime net ecosystem exchange of carbon dioxide at croplands

    NASA Astrophysics Data System (ADS)

    Zhao, P.; Lüers, J.

    2012-03-01

    The eddy-covariance technique is applied worldwide to acquire information about carbon exchange between a variety of ecosystems and atmosphere, but the data acquisition only covers, on average, two-thirds of the whole year due to system failures and data rejection. Therefore, data must be corrected and data gaps must be filled to provide seasonal or annual budgets. The gap-filing strategies, however, are still under discussion within the research community. Presently the major gap-filling methods work quite well for long-time running sites over slow-developing biosphere surfaces such as long-living evergreen forests, but difficulties appear for short-living and fast-growing croplands. In this study we developed a new Multi-Step Error Filter procedure to gain good-quality data as input for different parameterizations of the light response function of plants for two cropland sites (rice and potatoes), and we could prove that the conventional temperature binning approach is inadequate. The presented time-window scheme showed best results with a four-day time window for the potato field and an eight-day time window for the rice field. The influence of vapor pressure deficit was tested as well, but in our case it plays a minor role at both the potato and the rice fields with the exception of the early growing stage of the potatoes. Completing our research, we suggest an innovative method by introducing a Leaf Area Index factor to capture the seasonal vegetation development. With this method we are now able to fill the large gaps between observation periods when conventional methods are invalid.

  17. Quantifying species trait-function relationships for ecosystem management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of the world's ecosystems are managed to provide ecosystem functions and services on which we rely. Even with recent advances, ecosystem managers lack a clear methodology for applying basic knowledge of plant traits to meet management goals. Questions: Can we develop a methodology to a...

  18. 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...

  19. Monsoon variability, crop water requirement, and crop planning for kharif rice in Sagar Island, India.

    PubMed

    Mandal, S; Choudhury, B U; Satpati, L N

    2015-12-01

    In the Sagar Island of Bay of Bengal, rainfed lowland rice is the major crop, grown solely depending on erratic distribution of southwest monsoon (SM) rainfall. Lack of information on SM rainfall variability and absence of crop scheduling accordingly results in frequent occurrence of intermittent water stress and occasional crop failure. In the present study, we analyzed long period (1982-2010) SM rainfall behavior (onset, withdrawal, rainfall and wetness indices, dry and wet spells), crop water requirement (CWR, by Food and Agriculture Organization (FAO) 56), and probability of weekly rainfall occurrence (by two-parameter gamma distribution) to assess the variability and impact on water availability, CWR, and rice productivity. Finally, crop planning was suggested to overcome monsoon uncertainties on water availability and rice productivity. Study revealed that the normal onset and withdrawal weeks for SM rainfall were 22nd ± 1 and 43rd ± 2 meteorological weeks (MW), respectively. However, effective monsoon rainfall started at 24th MW (rainfall 92.7 mm, p > 56.7 % for 50 mm rainfall) and was terminated by the end of 40th MW (rainfall 90.7 mm, p < 59.6 % for 50 mm rainfall). During crop growth periods (seed to seed, 21st to 45th MW), the island received an average weekly rainfall of 65.1 ± 25.9 mm, while the corresponding weekly CWR was 47.8 ± 5.4 mm. Despite net water surplus of 353.9 mm during crop growth periods, there was a deficit of 159.5 mm water during MW of 18-23 (seedling raising) and MW of 41-45 (flowering to maturity stages). Water stress was observed in early lag vegetative stage of crop growth (32nd MW). The total dry spell frequency during panicle initiation and heading stage was computed as 40 of which 6 dry spells were >7 days in duration and reflected a significant (p < 0.05) increasing trend (at 0.22 days year(-1)) over the years (1982-2010). The present study highlights the adaptive capacity of crop planning including abiotic stress-tolerant cultivars to monsoon rainfall variability for sustaining rainfed rice production vis-à-vis food and livelihood security in vulnerable islands of coastal ecosystem. PMID:25903760

  20. Monsoon variability, crop water requirement, and crop planning for kharif rice in Sagar Island, India

    NASA Astrophysics Data System (ADS)

    Mandal, S.; Choudhury, B. U.; Satpati, L. N.

    2015-12-01

    In the Sagar Island of Bay of Bengal, rainfed lowland rice is the major crop, grown solely depending on erratic distribution of southwest monsoon (SM) rainfall. Lack of information on SM rainfall variability and absence of crop scheduling accordingly results in frequent occurrence of intermittent water stress and occasional crop failure. In the present study, we analyzed long period (1982-2010) SM rainfall behavior (onset, withdrawal, rainfall and wetness indices, dry and wet spells), crop water requirement (CWR, by Food and Agriculture Organization (FAO) 56), and probability of weekly rainfall occurrence (by two-parameter gamma distribution) to assess the variability and impact on water availability, CWR, and rice productivity. Finally, crop planning was suggested to overcome monsoon uncertainties on water availability and rice productivity. Study revealed that the normal onset and withdrawal weeks for SM rainfall were 22nd ± 1 and 43rd ± 2 meteorological weeks (MW), respectively. However, effective monsoon rainfall started at 24th MW (rainfall 92.7 mm, p > 56.7 % for 50 mm rainfall) and was terminated by the end of 40th MW (rainfall 90.7 mm, p < 59.6 % for 50 mm rainfall). During crop growth periods (seed to seed, 21st to 45th MW), the island received an average weekly rainfall of 65.1 ± 25.9 mm, while the corresponding weekly CWR was 47.8 ± 5.4 mm. Despite net water surplus of 353.9 mm during crop growth periods, there was a deficit of 159.5 mm water during MW of 18-23 (seedling raising) and MW of 41-45 (flowering to maturity stages). Water stress was observed in early lag vegetative stage of crop growth (32nd MW). The total dry spell frequency during panicle initiation and heading stage was computed as 40 of which 6 dry spells were >7 days in duration and reflected a significant ( p < 0.05) increasing trend (at 0.22 days year-1) over the years (1982-2010). The present study highlights the adaptive capacity of crop planning including abiotic stress-tolerant cultivars to monsoon rainfall variability for sustaining rainfed rice production vis-à-vis food and livelihood security in vulnerable islands of coastal ecosystem.

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

    PubMed

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

    2014-07-15

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

  2. 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 β-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 β-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

  3. Investigating options for attenuating methane emission from Indian rice fields.

    PubMed

    Singh, S N; Verma, Amitosh; Tyagi, Larisha

    2003-08-01

    The development of methods and strategies to reduce the emission of methane from paddy fields is a central component of ongoing efforts to protect the Earth's atmosphere and to avert a possible climate change. It appears from this investigation that there can be more than one strategy to contain methane emission from paddy fields, which are thought to be a major source of methane emission in tropical Asia. Promising among the mitigating options may be water management, organic amendments, fertilizer application and selection of rice cultivars. It is always better to adopt multi-pronged strategies to contain CH4 efflux from rice wetlands. Use of fermented manures with low C/N ratio, application of sulfate-containing chemical fertilizers, selection of low CH4 emitting rice cultivars, and implementation of one or two short aeration periods before the heading stage can be effective options to minimize CH4 emission from paddy fields. Among these strategies, water management, which appears to be the best cost-effective and eco-friendly way for methane mitigation, is only possible when excess water is available for reflooding after short soil drying at the right timing and stage. However, in tropical Asia, rice fields are naturally flooded during the monsoonal rainy season and fully controlled drainage is often impossible. In such situation, water deficits during the vegetative and reproductive stage may drastically affect the rice yields. Thus, care must be taken to mitigate methane emission without affecting rice yields. PMID:12742397

  4. Interaction between Vaccinium bracteatum Thunb. leaf pigment and rice proteins.

    PubMed

    Wang, Li; Xu, Yuan; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang; Fan, Meihua

    2016-03-01

    In this study, we investigated the interaction of Vaccinium bracteatum Thunb. leaf (VBTL) pigment and rice proteins. In the presence of rice protein, VBTL pigment antioxidant activity and free polyphenol content decreased by 67.19% and 68.11%, respectively, and L(∗) of the protein-pigment complex decreased significantly over time. L(∗) values of albumin, globulin and glutelin during 60-min pigment exposure decreased by 55.00, 57.14, and 54.30%, respectively, indicating that these proteins had bound to the pigment. A significant difference in protein surface hydrophobicity was observed between rice proteins and pigment-protein complexes, indicating that hydrophobic interaction is a major binding mechanism between VBTL pigment and rice proteins. A significant difference in secondary structures between proteins and protein-pigment complexes was also uncovered, indicating that hydrogen bonding may be another mode of interaction between VBTL pigment and rice proteins. Our results indicate that VBTL pigment can stain rice proteins with hydrophobic and hydrogen interactions. PMID:26471554

  5. Selection on grain shattering genes and rates of rice domestication.

    PubMed

    Zhang, Lin-Bin; Zhu, Qihui; Wu, Zhi-Qiang; Ross-Ibarra, Jeffrey; Gaut, Brandon S; Ge, Song; Sang, Tao

    2009-11-01

    Molecular cloning of major quantitative trait loci (QTLs) responsible for the reduction of rice grain shattering, a hallmark of cereal domestication, provided opportunities for in-depth investigation of domestication processes. Here, we studied nucleotide variation at the shattering loci, sh4 and qSH1, for cultivated rice, Oryza sativa ssp. indica and Oryza sativa ssp. japonica, and the wild progenitors, Oryza nivara andOryza rufipogon. The nonshattering sh4 allele was fixed in all rice cultivars, with levels of sequence polymorphism significantly reduced in both indica and japonica cultivars relative to the wild progenitors. The sh4 phylogeny together with the neutrality tests and coalescent simulations suggested that sh4 had a single origin and was fixed by artificial selection during the domestication of rice. Selection on qSH1 was not detected in indica and remained unclear in japonica. Selection on sh4 could be strong enough to have driven its fixation in a population of cultivated rice within a period of c. 100 yr. The slow fixation of the nonshattering phenotype observed at the archeological sites might be a result of relatively weak selection on mutations other than sh4 in early rice cultivation. The fixation of sh4 could have been achieved later through strong selection for the optimal phenotype. PMID:19674325

  6. Characterization of volatile aroma compounds in cooked black rice.

    PubMed

    Yang, Dong Sik; Lee, Kyu-Seong; Jeong, O-Young; Kim, Kee-Jong; Kays, Stanley J

    2008-01-01

    Black rice ( Oryza sativa L.), an aromatic specialty rice popular in Asia, has a unique flavor, the volatile chemistry of which has not been reported. The objectives of this research were to study volatile profiles of cooked black rice and to characterize the odor-active compounds. Thirty-five volatile compounds were identified by gas chromatography-mass spectrometry using a dynamic headspace system with Tenax trapping. Aldehydes and aromatics were quantitatively in the greatest abundance, accounting for 80.1% of total relative concentration of volatiles. The concentration of 2-acetyl-1-pyrroline (2-AP) was high, exceeded only by hexanal, nonanal, and 2-pentylfuran. A total of 25 odor-active compounds, determined by gas chromatography-olfactometry, were applied to principal component analysis, demonstrating significant differences between a black and a traditional white rice cultivar in terms of aroma and explaining 93.0% of the total variation. 2-AP, guaiacol, indole, and p-xylene largely influenced the difference between the aroma in cooked black and white rice. 2-AP and guaiacol were major contributors to the unique character of black rice based on odor thresholds, relative concentrations, and olfactometry. PMID:18081248

  7. 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

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

    TOXLINE Toxicology Bibliographic Information

    Smith E; Juhasz AL; 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 grain<rice 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.

  9. Is there a second fragrance gene in rice?

    PubMed

    Fitzgerald, Melissa A; Sackville Hamilton, N Ruaraidh; Calingacion, Mariafe N; Verhoeven, Harrie A; Butardo, Vito M

    2008-05-01

    Aromatic rice is highly prized by most rice consumers, and many countries cultivate traditional and improved aromatic varieties. 2-Acetyl-1-pyrroline (2AP) is the major aromatic compound in rice, and is believed to accumulate because of an eight-base-pair (8-bp) deletion in an allele at the fragrance locus. In this study, 2AP was quantified and the presence or absence of the fragrance allele (fgr) was determined in 464 samples of traditional varieties of rice from the T.T. Chang Genetic Resources Centre at the International Rice Research Institute. It was shown that a number of aromatic varieties, primarily from South and South-East Asia, do not carry the 8-bp deletion, but 2AP was identified in both raw and cooked rice of these varieties. We suggest that the 8-bp deletion in fgr is not the only cause of aroma, and at least one other mutation drives the accumulation of 2AP. The amount of 2AP in most uniform fgr genotypes was not significantly different from that in aromatic nfgr genotypes, but several fgr genotypes, primarily from South Asia, reproducibly accumulated exceptionally large amounts of 2AP. We suggest that the mutation leading to 2AP in aromatic nfgr varieties possibly originated several times and, through either domestication or evolution, the fgr gene and other alleles leading to 2AP have combined in South Asia, leading to several highly aromatic traditional varieties. The identification of multiple mutations for 2AP will enable rice breeding programmes to select actively for multiple genetic sources of 2AP, leading to the development of highly aromatic and, consequently, high-quality varieties of rice. PMID:18331415

  10. 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

  11. Rice: The First Crop Genome.

    PubMed

    Jackson, Scott A

    2016-12-01

    Rice was the first sequenced crop genome, paving the way for the sequencing of additional and more complicated crop genomes. The impact that the genome sequence made on rice genetics and breeding research was immediate, as evidence by citations and DNA marker use. The impact on other crop genomes was evident too, particularly for those within the grass family. As we celebrate 10 years since the completion of the rice genome sequence, we look forward to new empowering tool sets that will further revolutionize research in rice genetics and breeding and result in varieties that will continue to feed a growing population. PMID:27003180

  12. 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

  13. Genetic differentiation revealed by selective loci of drought-responding EST-SSRs between upland and lowland rice in China.

    PubMed

    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

  14. 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.

  15. Archaeal Population Dynamics during Sequential Reduction Processes in Rice Field Soil

    PubMed Central

    Lueders, Tillmann; Friedrich, Michael

    2000-01-01

    The population dynamics of Archaea after flooding of an Italian rice field soil were studied over 17 days. Anoxically incubated rice field soil slurries exhibited a typical sequence of reduction processes characterized by reduction of nitrate, Fe3+, and sulfate prior to the initiation of methane production. Archaeal population dynamics were followed using a dual approach involving molecular sequence retrieval and fingerprinting of small-subunit (SSU) rRNA genes. We retrieved archaeal sequences from four clone libraries (30 each) constructed for different time points (days 0, 1, 8, and 17) after flooding of the soil. The clones could be assigned to known methanogens (i.e., Methanosarcinaceae, Methanosaetaceae, Methanomicrobiaceae, and Methanobacteriaceae) and to novel euryarchaeotal (rice clusters I, II, and III) and crenarchaeotal (rice clusters IV and VI) lineages previously detected in anoxic rice field soil and on rice roots (R. Grosskopf, S. Stubner, and W. Liesack, Appl. Environ. Microbiol. 64:4983–4989, 1998). During the initiation of methanogenesis (days 0 to 17), we detected significant changes in the frequency of individual clones, especially of those affiliated with the Methanosaetaceae and Methanobacteriaceae. However, these findings could not be confirmed by terminal restriction fragment length polymorphism (T-RFLP) analysis of SSU rDNA amplicons. Most likely, the fluctuations in sequence composition of clone libraries resulted from cloning bias. Clonal SSU rRNA gene sequences were used to define operational taxonomic units (OTUs) for T-RFLP analysis, which were distinguished by group-specific TaqI restriction sites. Sequence analysis showed a high degree of conservation of TaqI restriction sites within the different archaeal lineages present in Italian rice field soil. Direct T-RFLP analysis of archaeal populations in rice field soil slurries revealed the presence of all archaeal lineages detected by cloning with a predominance of terminal restriction fragments characteristic of rice cluster I (389 bp), Methanosaetaceae (280 bp), and Methanosarcinaceae/rice cluster VI (182 bp). In general, the relative gene frequency of most detected OTUs remained rather constant over time during the first 17 days after flooding of the soil. Most minor OTUs (e.g., Methanomicrobiaceae and rice cluster III) and Methanosaetaceae did not change in relative frequency. Rice cluster I (37 to 30%) and to a lesser extent rice cluster IV as well as Methanobacteriaceae decreased over time. Only the relative abundance of Methanosarcinaceae (182 bp) increased, roughly doubling from 15 to 29% of total archaeal gene frequency within the first 11 days, which was positively correlated to the dynamics of acetate and formate concentrations. Our results indicate that a functionally dynamic ecosystem, a rice field soil after flooding, was linked to a relatively stable archaeal community structure. PMID:10877762

  16. Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein.

    PubMed

    2006-01-01

    This report addresses the safety of cosmetic ingredients derived from rice, Oryza sativa. Oils, Fatty Acids, and Waxes: Rice Bran Oil functions in cosmetics as a conditioning agent--occlusive in 39 formulations across a wide range of product types. Rice Germ Oil is a skin-conditioning agent--occlusive in six formulations in only four product categories. Rice Bran Acid is described as a surfactant-cleansing agent, but was not in current use. Rice Bran Wax is a skin-conditioning agent--occlusive in eight formulations in five product categories. Industry did not directly report any use of Rice Bran Wax. Hydrogenated Rice Bran Wax is a binder, skin-conditioning agent--occlusive, and viscosity-increasing agent--nonaqueous in 11 formulations in six product categories. Rice Bran Oil had an oral LD50 of > 5 g/kg in white rats and Rice Wax had an oral LD50 of > 24 g/kg in male mice. A three-generation oral dosing study reported no toxic or teratologic effects in albino rats fed 10% Rice Bran Oil compared to a control group fed Peanut Oil. Undiluted Rice Bran Oil, Rice Germ Oil, and Hydrogenated Rice Bran Wax were not irritants in animal skin tests. Rice Bran Oil was not a sensitizer. Rice Bran Oil, Rice Germ Oil, Rice Wax, and Hydrogenated Rice Bran Wax were negative in ocular toxicity assays. A mixture of Rice Bran Oil and Rice Germ Oil had a ultraviolet (UV) absorption maximum at 315 nm, but was not phototoxic in a dermal exposure assay. Rice Bran Oil was negative in an Ames assay, and a component, gamma-oryzanol, was negative in bacterial and mammalian mutagenicity assays. Rice oils, fatty acids, and waxes were, at most, mildly irritating in clinical studies. Extracts: Rice Bran Extract is used in six formulations in four product categories. Rice Extract is a hair-conditioning agent, but was not in current use. Hydrolyzed Rice Extract is used in four formulations and current concentration of use data were provided for other uses. Hydrolyzed Rice Bran Extract, described as a skin-conditioning agent--miscellaneous, is used in two product categories. Use concentrations are in the 1% to 2% range. Rice Bran Extract is comprised of proteins, lipids, carbohydrates, mineral ash, and water. The content includes palmitic, stearic, oleic, and linoleic acids. Other components include antioxidants such as tocopherols. Rice Extract reduced the cytotoxicity of sodium chloride in male rats. Bran, Starch and Powder: Rice Bran (identified as rice hulls) is an abrasive and bulking agent in one formulation. Rice Starch is an absorbent and bulking agent in 51 formulations across a wide range of product categories. Rice Germ Powder is an abrasive and one manufacturer described an exfoliant use, but it was not reported to be used in 2002. Oral carcinogenicity studies done on components of Rice Bran (phytic acid and gamma-oryzanol) were negative. Rice Bran did not have an anticarcinogenic effect on 1,2-dimethylhydrazine-induced large bowel tumors. In cocarcinogenicity studies done using 1,2-dimethylhydrazine and other agents, with Rice Bran Oil and Rice Bran-derived hemicellulose and saccharide, tumor inhibition was observed; gamma-oryzanol did not inhibit the development of neoplasms. A decrease in cutaneous lesions in atopic dermatitis patients was reported following bathing with a Rice Bran preparation. Proteins: Hydrolyzed Rice Bran Protein and Hydrolyzed Rice Protein function as conditioning agents (hair or skin), but only the latter was reported to be used in a few products. An in vitro phototoxicity assay using UVA light found no photochemical toxicity. Rice bran protein hydrolysates are not acutely toxic, are not skin or ocular irritants in animals, are not skin sensitizers in guinea pig maximization tests, and are not irritating or sensitizing in clinical tests. Isolated cases of allergy to raw rice have been reported, but rice, in general, is considered non allergenic. The Cosmetic Ingredient Review (CIR) Expert Panel considered that safety test data available on certain of these ingredients could be extrapolated to the entire group. Although Rice Bran Extract does contain UV absorbing compounds at low concentrations, clinical experience suggested no phototoxicity would be associated with such materials. Rice derived ingredients generally are considered to be non allergenic. There were no safety test data available for Hydrolyzed Rice Extract and Hydrolyzed Rice Bran Extract, but their safety may be inferred from that of the extracts from which they are derived. Current levels of polychlorinated biphenyls (PCBs) and heavy metals in rice-derived ingredients used in cosmetics are not a safety concern. The Panel was concerned, however, that contaminants such as pesticides have been reported in Rice Bran Oil used for cooking. Pesticides and heavy metals should not exceed currently reported levels for rice-derived cosmetic ingredients. The CIR Expert Panel concluded that these rice-derived ingredients are safe as cosmetic ingredients in the practices of use and concentrations as described in this safety assessment. PMID:17090480

  17. Contributions of climate, varieties, and agronomic management to rice yield change in the past three decades in China

    NASA Astrophysics Data System (ADS)

    Zhang, He; Tao, Fulu; Xiao, Dengpan; Shi, Wenjiao; Liu, Fengshan; Zhang, Shuai; Liu, Yujie; Wang, Meng; Bai, Huizi

    2015-10-01

    The long-term field experiment data at four representative agro-meteorological stations, together with a crop simulation model, were used to disentangle the contributions of climate change, variety renewal, and fertilization management to rice yield change in the past three decades. We found that during 1981-2009 varieties renewal increased rice yield by 16%-52%, management improvement increased yield by 0-16%, and the contributions of climate change to rice yield varied from — 16% to 10%. Varieties renewal and management improvement offset the negative impacts of climate change on rice production. Among the major climate variables, decreases in solar radiation reduced rice yield on average by 0.1%per year. The impact of temperature change had an explicit spatial pattern. It increased yield by 0.04%-0.4% per year for single rice at Xinbin and Ganyu station and for late rice at Tongcheng station, by contrast reduced yield by 0.2%-0.4% per year for single rice at Mianyang station and early rice at Tongcheng station. During 1981-2009, rice varieties renewal was characterized by increases in thermal requirements, grain number per spike and harvest index. The new varieties were less sensitive to climate change than old ones. The development of high thermal requirements, high yield potential and heat tolerant rice varieties, together with improvement of agronomic management, should be encouraged to meet the challenges of climate change and increasing food demand in future.

  18. Contributions of climate, varieties, and agronomic management to rice yield change in the past three decades in China

    NASA Astrophysics Data System (ADS)

    Zhang, He; Tao, Fulu; Xiao, Dengpan; Shi, Wenjiao; Liu, Fengshan; Zhang, Shuai; Liu, Yujie; Wang, Meng; Bai, Huizi

    2016-06-01

    The long-term field experiment data at four representative agro-meteorological stations, together with a crop simulation model, were used to disentangle the contributions of climate change, variety renewal, and fertilization management to rice yield change in the past three decades. We found that during 1981-2009 varieties renewal increased rice yield by 16%-52%, management improvement increased yield by 0-16%, and the contributions of climate change to rice yield varied from — 16% to 10%. Varieties renewal and management improvement offset the negative impacts of climate change on rice production. Among the major climate variables, decreases in solar radiation reduced rice yield on average by 0.1%per year. The impact of temperature change had an explicit spatial pattern. It increased yield by 0.04%-0.4% per year for single rice at Xinbin and Ganyu station and for late rice at Tongcheng station, by contrast reduced yield by 0.2%-0.4% per year for single rice at Mianyang station and early rice at Tongcheng station. During 1981-2009, rice varieties renewal was characterized by increases in thermal requirements, grain number per spike and harvest index. The new varieties were less sensitive to climate change than old ones. The development of high thermal requirements, high yield potential and heat tolerant rice varieties, together with improvement of agronomic management, should be encouraged to meet the challenges of climate change and increasing food demand in future.

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  20. Genome-Wide Association of Rice Blast Disease Resistance and Yield-Related Components of Rice.

    PubMed

    Wang, Xueyan; Jia, Melissa H; Ghai, Pooja; Lee, Fleet N; Jia, Yulin

    2015-12-01

    Robust disease resistance may require an expenditure of energy that may limit crop yield potential. In the present study, a subset of a United States Department of Agriculture rice core collection consisting of 151 accessions was selected using a major blast resistance (R) gene, Pi-ta, marker and was genotyped with 156 simple sequence repeat (SSR) markers. Disease reactions to Magnaporthe oryzae, the causal agent of rice blast disease, were evaluated under greenhouse and field conditions, and heading date, plant height, paddy and brown seed weight in two field environments were analyzed, using an association mapping approach. A total of 21 SSR markers distributed among rice chromosomes 2 to 12 were associated with blast resistance, and 16 SSR markers were associated with seed weight, heading date, and plant height. Most noticeably, shorter plants were significantly correlated with resistance to blast, rice genomes with Pi-ta were associated with lighter seed weights, and the susceptible alleles of RM171 and RM6544 were associated with heavier seed weight. These findings unraveled a complex relationship between disease resistance and yield-related components. PMID:26284908

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

    PubMed Central

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

    2014-01-01

    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

  2. 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

  3. Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil.

    PubMed

    Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

    2015-01-01

    Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using (13)C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems. PMID:25944542

  4. Quantitative phosphoproteomic analysis of early seed development in rice (Oryza sativa L.).

    PubMed

    Qiu, Jiehua; Hou, Yuxuan; Tong, Xiaohong; Wang, Yifeng; Lin, Haiyan; Liu, Qing; Zhang, Wen; Li, Zhiyong; Nallamilli, Babi R; Zhang, Jian

    2016-02-01

    Rice (Oryza sativa L.) seed serves as a major food source for over half of the global population. Though it has been long recognized that phosphorylation plays an essential role in rice seed development, the phosphorylation events and dynamics in this process remain largely unknown so far. Here, we report the first large scale identification of rice seed phosphoproteins and phosphosites by using a quantitative phosphoproteomic approach. Thorough proteomic studies in pistils and seeds at 3, 7 days after pollination resulted in the successful identification of 3885, 4313 and 4135 phosphopeptides respectively. A total of 2487 proteins were differentially phosphorylated among the three stages, including Kip related protein 1, Rice basic leucine zipper factor 1, Rice prolamin box binding factor and numerous other master regulators of rice seed development. Moreover, differentially phosphorylated proteins may be extensively involved in the biosynthesis and signaling pathways of phytohormones such as auxin, gibberellin, abscisic acid and brassinosteroid. Our results strongly indicated that protein phosphorylation is a key mechanism regulating cell proliferation and enlargement, phytohormone biosynthesis and signaling, grain filling and grain quality during rice seed development. Overall, the current study enhanced our understanding of the rice phosphoproteome and shed novel insight into the regulatory mechanism of rice seed development. PMID:26613898

  5. Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil

    PubMed Central

    Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

    2015-01-01

    Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using 13C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems. PMID:25944542

  6. Anti-oxidative analysis, and identification and quantification of anthocyanin pigments in different coloured rice.

    PubMed

    Chen, Xiao Qiong; Nagao, Norio; Itani, Tomio; Irifune, Kohei

    2012-12-15

    Anthocyanin pigments in coloured rice cultivars were isolated and identified using high-performance liquid chromatography techniques. Two black rice cultivars (Asamurasaki, Okunomurasaki) contained three major anthocyanins: cyanidin-3-glucoside, peonidin-3-glucoside and malvidin. Chinakuromai (black) rice additionally contained a fourth anthocyanin, petunidin-3-glucoside. Four red rice cultivars contained only malvidin. The total anthocyanin content varied greatly among black rice cultivars (79.5-473.7 mg/100g), but was lower in red rice (7.9-34.4 mg/100g). Total phenolic content was similar between red (460.32-725.69 mg/100g) and black (417.11-687.24 mg/100g) rice. The oxygen radical absorbing capacity was ranked as follows: red (69.91-130.32 ?mol Trolox/g)>black (55.49-64.85 ?mol Trolox/g)>green (35.32 ?mol Trolox/g)>white (21.81 ?mol Trolox/g) rice. The antioxidant capacity resulted mainly from the seed capsule, not the endosperm. The anthocyanin pigments contributed little to the total antioxidant capacity of red (0.03-0.1%) and black (0.5-2.5%) rice cultivars. Hence, the antioxidant capacity is derived mainly from other phenolic compounds. PMID:22980872

  7. Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil

    NASA Astrophysics Data System (ADS)

    Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

    2015-05-01

    Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using 13C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems.

  8. Ecosystem services: Valuing ecosystems for climate

    NASA Astrophysics Data System (ADS)

    Hungate, Bruce A.; Hampton, Haydee M.

    2012-03-01

    Ecosystems regulate climate through biogeochemistry and biophysics, but current policies only recognize biogeochemical influences. A new proposal to include biophysical effects changes the climate value of ecosystems, and sets the stage to expand the suite of climate regulation services considered in global policies and carbon markets.

  9. Major Links.

    ERIC Educational Resources Information Center

    Henderson, Tona

    1995-01-01

    Provides electronic mail addresses for resources and discussion groups related to the following academic majors: art, biology, business, chemistry, computer science, economics, health sciences, history, literature, math, music, philosophy, political science, psychology, sociology, and theater. (AEF)

  10. Spatiotemporal simulation of changes in rice cropping systems in the Mekong Delta, Vietnam

    NASA Astrophysics Data System (ADS)

    Chen, Cheng-Ru; Chen, Chi-Farn; Son, Nguyen-Thanh

    2015-04-01

    With the dramatic development of agro-economics, population growth, and climate change, the rice cropping systems in the Vietnamese Mekong Delta (VMD) have been undergoing a major change. Information on rice cropping practices and changes in cropping systems is critical for policymakers to devise successful strategies to ensure food security and rice grain exports for the country. The primary objective of this research is to map rice cropping systems and predict future dynamics of rice cropping systems using MODIS time-series data from 2002 to 2012. A phenology-based classification approach was applied for the classification and assessment of rice cropping systems. Then, the Cellular Automata-Markov (CA-Markov) model was used to simulate future changes in rice-cropping activities. To obtain precise prediction, a calibration of CA-Markov were implemented by using a series of rice crop maps. The comparisons between the classification maps and the ground reference data indicated satisfactory results with overall accuracies above 81%, and Kappa coefficients above 0.75, respectively. The simulated maps of rice cropping systems for 2010-2012 were extrapolated by CA-Markov model based on the trend of rice cropping systems during 2002-2009. The comparison between the predicted scenarios and the classification maps for 2010-2012 presents a reasonably close agreement. In summary, the CA-Markov model with a long-term calibration confirmed the validity of the approach for dynamic modeling of changes in rice cropping systems in the study region. The results obtained from this study demonstrate that the approach produced satisfactory results in terms of accuracy, quantitative forecast, and spatial pattern changes. Thus, projections of future changes would provide useful information for the agricultural policymakers in respect to formulating effective management strategies of rice cropping practices in VMD.

  11. 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

  12. Neglecting rice milling yield and quality underestimates economic losses from high-temperature stress.

    PubMed

    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. 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.

  14. 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...

  15. Estuarine Total Ecosystem Metabolism

    EPA Science Inventory

    Total ecosystem metabolism (TEM), both as discrete measurements and as a theoretical concept, has an important history in ecosystem ecology, particularly in estuaries. Some of the earliest ecological studies were developed to determine how energy flowed through an ecosystem and w...

  16. 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 ...

  17. 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...

  18. POULTRY LITTER INDUCES RICE TILLERING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry litter (PL) is used as a soil amendment for numerous crops, including rice. While it is known that rice growth is improved by PL, little study has been carried out to identify the specific growth parameters that are altered. We have identified a marked increase in the number of tillers (sh...

  19. Update on organic rice research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic products command a premium in the marketplace and bring greater farmgate value to growers and processors. Although total rice acreage has decreased in Texas over the last ten years, there has been an increase in rice acreage produced under organic management. USDA ARS has conducted research ...

  20. 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.

  1. Consideration of Ecosystem for ICME

    SciTech Connect

    Ren, Weiju

    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.

  2. Genes controlling root development in rice.

    PubMed

    Mai, Chung D; Phung, Nhung Tp; To, Huong Tm; Gonin, Mathieu; Hoang, Giang T; Nguyen, Khanh L; Do, Vinh N; Courtois, Brigitte; Gantet, Pascal

    2014-12-01

    In this review, we report on the recent developments made using both genetics and functional genomics approaches in the discovery of genes controlling root development in rice. QTL detection in classical biparental mapping populations initially enabled the identification of a very large number of large chromosomal segments carrying root genes. Two segments with large effects have been positionally cloned, allowing the identification of two major genes. One of these genes conferred a tolerance to low phosphate content in soil, while the other conferred a tolerance to drought by controlling root gravitropism, resulting in root system expansion deep in the soil. Findings based on the higher-resolution QTL detection offered by the development of association mapping are discussed. In parallel with genetics approaches, efforts have been made to screen mutant libraries for lines presenting alterations in root development, allowing for the identification of several genes that control different steps of root development, such as crown root and lateral root initiation and emergence, meristem patterning, and the control of root growth. Some of these genes are closely phylogenetically related to Arabidopsis genes involved in the control of lateral root initiation. This close relationship stresses the conservation among plant species of an auxin responsive core gene regulatory network involved in the control of post-embryonic root initiation. In addition, we report on several genetic regulatory pathways that have been described only in rice. The complementarities and the expected convergence of the direct and reverse genetic approaches used to decipher the genetic determinants of root development in rice are discussed in regards to the high diversity characterizing this species and to the adaptations of rice root system architecture to different edaphic environments. PMID:26224559

  3. A hydroponic rice seedling culture model system for investigating proteome of salt stress in rice leaf.

    PubMed

    Kim, Dea-Wook; Rakwal, Randeep; Agrawal, Ganesh Kumar; Jung, Young-Ho; Shibato, Junko; Jwa, Nam-Soo; Iwahashi, Yumiko; Iwahashi, Hitoshi; Kim, Du Hyun; Shim, Ie-Sung; Usui, Kenji

    2005-12-01

    By using an in vivo hydroponic rice seedling culture system, we investigated the physiological and biochemical responses of a model rice japonica cultivar Nipponbare to salt stress using proteomics and classical biochemical methods. Yoshida's nutrient solution (YS) was used to grow rice seedlings. YS-grown 18-day-old seedlings manifested highly stable and reproducible symptoms, prominently the wilting and browning of the 3rd leaf, reduced photosynthetic activity, inhibition in overall seedling growth, and failure to develop new (5th) leaf, when subjected to salt stress by transferring them to YS containing 130 mM NaCl for 4 days. As leaf response to salt stress is least investigated in rice by proteomics, we used the 3rd leaf as source material. A comparison of 2-DE protein profiles between the untreated control and salt-stressed 3rd leaves revealed 55 differentially expressed CBB-stained spots, where 47 spots were increased over the control. Of these changed spots, the identity of 33 protein spots (27 increased and 5 decreased) was determined by nESI-LC-MS/MS. Most of these identified proteins belonged to major metabolic processes like photosynthetic carbon dioxide assimilation and photorespiration, suggesting a good correlation between salt stress-responsive proteins and leaf morphology. Moreover, 2-DE immunoblot and enzymatic activity analyses of 3rd leaves revealed remarkable changes in the key marker enzymes associated with oxidative damage to salt stress: ascorbate peroxidase and lipid peroxidation were induced, and catalase was suppressed. These results demonstrate that hydroponic culture system is best suited for proteomics of salt stress in rice seedling. PMID:16315177

  4. Landscape ecosystems of the University of Michigan Biological Station: Ecosystem diversity and ground-cover diversity

    SciTech Connect

    Pearsall, D.R.

    1995-12-31

    The aim of this research is to provide an understanding of the three-dimensional (air-earth-organism) units of the landscape of the University of Michigan Biological Station (UMBS) that the author calls landscape ecosystem types, or simply ecosystems. Specifically, he has focused on the kinds, spatial location and patterns, and composition (physiography, soil, vegetation) of the local landscape ecosystem types of UMBS and Colonial Point. Future research on the functioning of these ecosystems together with inventories of their plant and animal life will add significantly to the landscape ecology research that has been initiated. A major reason for this research is to provide the conceptual basis and baseline data for understanding ecosystem change. Although it is popular to speak of climate change, entire ecosystems change; some components change faster than others.

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

    PubMed

    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

  6. 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.

  7. 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

  8. Identification of blast resistance genes for managing rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating diseases worldwide. In the present study, an international set of monogenic differentials carrying 24 major blast resistance (R) genes (Pia, Pib, Pii, Pik, Pik-h, Pik-m, Pik-p, Pik-s, Pish, Pit, Pita, Pita2,...

  9. 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...

  10. Genotype x Management interactions influencing susceptibility to rice grain smuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain smuts have historically been considered minor diseases of rice in the United States. In recent years localized infestations of kernel smut and increased prevalence of false smut have raised interest in these diseases. Although major gene resistance has not been described for either disease, ...

  11. Ancestral genome duplication in rice.

    PubMed

    Guyot, Romain; Keller, Beat

    2004-06-01

    The recent availability of the pseudochromosome sequences of rice allows for the first time the investigation of the extent of intra-genomic duplications on a large scale in this agronomically important species. Using a dot-matrix plotter as a tool to display pairwise comparisons of ordered predicted coding sequences along rice pseudochromosomes, we found that the rice genome contains extensive chromosomal duplications accounting for 53% of the available sequences. The size of duplicated blocks is considerably larger than previously reported. In the rice genome, a duplicated block size of >1 Mb appears to be the rule and not the exception. Comparative mapping has shown high genetic colinearity among chromosomes of cereals, promoting rice as a model for studying grass genomes. Further comparative genome analysis should allow the study of the conservation and evolution of these duplication events in other important cereals such as rye, barley, and wheat. PMID:15190378

  12. 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...

  13. 21 CFR 137.350 - Enriched rice.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose...

  14. 21 CFR 137.350 - Enriched rice.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose...

  15. 21 CFR 137.350 - Enriched rice.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose...

  16. 21 CFR 137.350 - Enriched rice.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose...

  17. 21 CFR 137.350 - Enriched rice.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  18. 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. ...

  19. 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

  20. Metabolic flux analysis of diterpene biosynthesis pathway in rice.

    PubMed

    Chang, Yung-Jin; Kim, Bo-Ra; Kim, Soo-Un

    2005-09-01

    Relative transcript levels of eight rice diterpene cyclases at the branch points of gibberellins and phytoalexins biosynthesis pathway were measured by reverse transcription quantitative PCR. Metabolic flux analysis by the distribution ratio of common substrate showed that UV-irradiation of etiolated rice seedlings decreased the flux for primary metabolism of gibberellins biosynthesis by half (from 62 to 27%) and 41% of geranylgeranyl pyrophosphate was used for induction of pimaradiene intermediate as the major phytoalexin. In comparison, light-illumination used almost all geranylgeranyl pyrophosphate (96%) for gibberellin biosynthesis to stimulate the plant growth and strongly repressed the metabolic flux for phytoalexins biosynthesis. PMID:16215852

  1. Isolation and identification of an allelopathic phenylethylamine in rice.

    PubMed

    Le Thi, Ho; Lin, Chung-Ho; Smeda, Reid J; Leigh, Nathan D; Wycoff, Wei G; Fritschi, Felix B

    2014-12-01

    Allelopathy is the process whereby an organic chemical (allelochemical) released from one plant influences the growth and development of other plants. Allelochemicals produced by specific rice (Oryza sativa L.) cultivars have potential to manage barnyard grass (Echinochloa crus-galli L.), a major yield-limiting weed species in rice production systems in Asia and North America. In this study, isolation and identification of an allelopathic compound, N-trans-cinnamoyltyramine (NTCT), in a Vietnamese rice cultivar 'OM 5930' was accomplished through bioassay-guided purification using reversed-phase liquid chromatography coupled with spectroscopic techniques, including tandem mass spectrometry, high resolution mass spectrometry, as well as one-dimensional and two-dimensional (1)H NMR and (13)C NMR spectroscopy. The identified compound, NTCT is considered a ?-phenylethylamine. NTCT inhibited root and hypocotyl growth of cress (Lepidium sativum L.), barnyard grass and red sprangletop (Leptochloa chinensis L. Nees) at concentrations as low as 0.24 ?M. The ED50 (concentration required for 50% inhibition) of NTCT on barnyard grass root and hypocotyl elongation were 1.35 and 1.85 ?M, respectively. Results further demonstrated that mortality of barnyard grass and red sprangletop seedlings was >80% at a concentration of 2.4 ?M of NTCT. By 20 days after transplanting, 0.425 nmol of NTCT per OM 5930 rice seedling was released into the culture solution. With concentrations of 42 ?g g(-1) fresh weight, production of NTCT in intact rice plants can be considered high. These findings suggest that developing plants of Vietnamese rice cultivar OM 5930 release NTCT and may be utilized to suppress barnyard grass in rice fields. The potency of NTCT may encourage development of this compound as a bio-herbicide. PMID:25212867

  2. Rice-gall midge interactions: Battle for survival.

    PubMed

    Bentur, Jagadish S; Rawat, Nidhi; Divya, D; Sinha, Deepak K; Agarrwal, Ruchi; Atray, Isha; Nair, Suresh

    2016-01-01

    Gall midges are insects specialized in maneuvering plant growth, metabolic and defense pathways for their benefit. The Asian rice gall midge and rice share such an intimate relationship that there is a constant battle for survival by either partner. Diverse responses by the rice host against the midge include necrotic hypersensitive resistance reaction, non-hypersensitive resistance reaction and gall-forming compatible interaction. Genetic studies have revealed that major R (resistance) genes confer resistance to gall midge in rice. Eleven gall midge R genes have been characterized so far in different rice varieties in India. In addition, no single R gene confers resistance against all the seven biotypes of the Asian rice gall midge, and none of the biotypes is virulent against all the resistance genes. Further, the interaction of the plant resistance gene with the insect avirulence gene is on a gene-for-gene basis. Our recent investigations involving suppressive subtraction hybridization cDNA libraries, microarray analyses, gene expression assays and metabolic profiling have revealed several molecular mechanisms, metabolite markers and pathways that are induced, down-regulated or altered in the rice host during incompatible or compatible interactions with the pest. This is also true for some of the pathways studied in the gall midge. Next generation sequencing technology, gene expression studies and conventional screening of gall midge cDNA libraries highlighted molecular approaches adopted by the insect to feed, survive and reproduce. This constant struggle by the midge to overcome the host defenses and the host to resist the pest has provided us with an opportunity to observe this battle for survival at the molecular level. PMID:26455891

  3. Thermal behavior and gelling interactions of Mesona Blumes gum and rice starch mixture.

    PubMed

    Feng, Tao; Ye, Ran; Zhuang, Haining; Fang, Zhongxiang; Chen, Hanqing

    2012-09-01

    In this research, thermal behavior and gelling interactions of Mesona Blumes gum (MBG)/rice starch mixture were extensively investigated. MBG/rice starch gel displayed significant endothermal and exothermal properties at different MBG concentrations, indicating essential interactions between MBG and rice starch. In addition, the gelling interaction between MBG and rice starch was studied by using hydrogen-bond forming agents (1,4-butanediol, ethane-1,2-diol, glycerol) and hydrogen-bond breaking agents (urea, tetramethyl urea, ethanol, methanol) on rheological spectra. The results indicated that the hydrogen bond between MBG, rice starch and water might be the major force of maintaining the complete structure of the mixed gel. Their hypothetic interactions have been schemed in computer using hyperchem 8.0. PMID:24751091

  4. 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

  5. Formation and emission of methane in rice soils: Experimental determination and modeling analysis. Final report

    SciTech Connect

    Law, V.J.; Bhattacharya, S.K.

    1993-08-31

    Rice paddy soils have been identified as a major source of methane emissions contributing to the observed atmospheric increase in methane. This points to the need for a method of quantifying and predicting methane emissions for the widely varying conditions used in rice agriculture throughout the world. In the present work, a mathematical model for estimating the emission of methane from rice paddy soils is developed and refined. Kinetic parameters for methanogenesis in a Louisiana rice soil are determined from laboratory data on methane production from acetic acid substrate. Use of a stirred reactor allows simultaneous measurement of acetate consumption and methane production while minimizing mass transfer limitations. An existing model for rice plant growth is utilized to provide data on the availability of root exudates as a carbon source for the methanogens. The final methane model includes the kinetic parameters, plant data, and estimated transport parameters. With adjustments in these parameters, it provides an acceptable match to field data.

  6. Proteomic profiling of rice embryos from a hybrid rice cultivar and its parental lines.

    PubMed

    Wang, Weiwei; Meng, Bo; Ge, Xiaomeng; Song, Shuhui; Yang, Yue; Yu, Xiaomin; Wang, Liguo; Hu, Songnian; Liu, Siqi; Yu, Jun

    2008-11-01

    Elite rice hybrids, when compared to their parental lines, exhibit increased yield and other favorable agronomical traits, such as pathogen- and water-stress resistances, which are described as heterosis, and the molecular mechanism of heterosis remains to be elucidated. Since genomic sequences of the paternal (9311) and maternal lines (P64S) of a major rice hybrid variety LYP9 (Liang-You-Pei-Jiu) were acquired recently, we performed a proteomic study on mature embryos of this hybrid triad based on 2-DE and MALDI-TOF MS analyses, and identified 54 differentially expressed proteins involved in major biological processes including nutrient reservoir, response to stress, and metabolism. We observed that most of the storage proteins exhibit overdominance and stress-induced proteins display additivity. We compared proteomic results with transcriptomic data generated from the same embryo samples and found 28 candidate heterosis-associated genes shared by the two datasets. We further traced back to their genomic structures including protein-coding and regulatory regions and found that most of these genes have multiple copies in rice genomes as paralogous genes. Based on alignment of coding and regulation regions, we found that most of the differentially expressed genes at both protein and RNA levels are recent gene duplicates (paralogous genes) with relative little difference in protein-coding regions between orthologous genes (between genes of the two parental genomes) as compared to regulatory regions that harbor numerous indels and base substitutions. PMID:18850630

  7. Gene flow from herbicide-resistant and non-resistant rice into red rice populations in U.S. rice fields: A survey of current evidence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diverse red rice types infest U.S. rice fields. These infestations have remained widespread despite recent successes in controlling red rice in newly-introduced herbicide-resistant rice systems. As a result, the distribution and genetic background of red rice, and the degree to which red rice inte...

  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. Remotely Sensed Rice Yield Prediction Using Multi-Temporal NDVI Data Derived from NOAA's-AVHRR

    PubMed Central

    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

  10. Biopharming to increase bioactive peptides in rice seed.

    PubMed

    Yang, Lijun; Wakasa, Yuhya; Takaiwa, Fumio

    2008-01-01

    The production of high-value pharmaceutical proteins and peptides in transgenic plants is an attractive and economically feasible alternative to conventional mammalian cell, yeast, and bacterial systems. In contrast to vegetative tissues, rice seeds allow higher accumulation of recombinant proteins and long-term stable storage. Rice is not only consumed as a staple food by a majority of the world's population, but is also used as a model monocot for biotechnological manipulation. Daily oral consumption of transgenic rice seeds that accumulate high concentrations of food-derived or synthetic bioactive peptides can be expected to provide a safe, reliable, and consistent oral delivery system that would contribute to the promotion of human health care. PMID:18727558

  11. Chemical contaminants in Canadian aquatic ecosystems

    SciTech Connect

    Pierce, R.C.; Whittle, D.M.; Bramwell, J.B.

    1998-12-31

    This report focuses on those chemicals that persist in the Canadian environment and that are accumulated by aquatic organisms. It summarizes scientific information collected previously, with emphasis on Canadian research findings published in the last decade. The first part of the report introduces the general features of aquatic ecosystems and provides basic information on the fate and effects of chemical contaminants. The second part reviews contaminant related issues for the following geographic areas: Atlantic marine ecosystems including the St. Lawrence, Bay of Fundy, and general north-west Atlantic; freshwater ecosystems including the Great Lakes and inland waters; the Arctic marine ecosystem; and Pacific aquatic ecosystems including the British Columbia coastal ecosystem, the open coast, and some of the major rivers. All chapters discuss the major contaminant issues, important oceanographic or limnological features, biological resources, and sources of contaminants as well as contaminant trends, distribution, and effects. Current and emerging chemical contaminant issues and associated research topics are summarized at the end of each chapter. The third part is an overall assessment of current knowledge of chemical contaminants and their effects on fish and fish habitat, and identifies major current and emerging contaminant issues confronting Canada`s fish and fish habitat.

  12. OsSPL13 controls grain size in cultivated rice.

    PubMed

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

    2016-04-01

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

  13. Marker-assisted backcrossing: a useful method for rice improvement

    PubMed Central

    Hasan, Muhammad Mahmudul; Rafii, Mohd Y.; Ismail, Mohd R.; Mahmood, Maziah; Rahim, Harun A.; Alam, Md. Amirul; Ashkani, Sadegh; Malek, Md. Abdul; Latif, Mohammad Abdul

    2015-01-01

    The world's population is increasing very rapidly, reducing the cultivable land of rice, decreasing table water, emerging new diseases and pests, and the climate changes are major issues that must be addressed to researchers to develop sustainable crop varieties with resistance to biotic and abiotic stresses. However, recent scientific discoveries and advances particularly in genetics, genomics and crop physiology have opened up new opportunities to reduce the impact of these stresses which would have been difficult if not impossible as recently as the turn of the century. Marker assisted backcrossing (MABC) is one of the most promising approaches is the use of molecular markers to identify and select genes controlling resistance to those factors. Regarding this, MABC can contribute to develop resistant or high-yielding or quality rice varieties by incorporating a gene of interest into an elite variety which is already well adapted by the farmers. MABC is newly developed efficient tool by which using large population sizes (400 or more plants) for the backcross F1 generations, it is possible to recover the recurrent parent genotype using only two or three backcrosses. So far, many high yielding, biotic and abiotic stresses tolerance, quality and fragrance rice varieties have been developed in rice growing countries through MABC within the shortest timeframe. Nowadays, MABC is being used widely in plant breeding programmes to develop new variety/lines especially in rice. This paper reviews recent literature on some examples of variety/ line development using MABC strategy. PMID:26019637

  14. 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

  15. Global Identification of Genes Specific for Rice Meiosis

    PubMed Central

    Zhang, Bingwei; Xu, Meng; Bian, Shiquan; Hou, Lili; Tang, Ding; Li, Yafei; Gu, Minghong; Cheng, Zhukuan; Yu, Hengxiu

    2015-01-01

    The leptotene-zygotene transition is a major step in meiotic progression during which pairing between homologous chromosomes is initiated and double strand breaks occur. OsAM1, a homologue of maize AM1 and Arabidopsis SWI1, encodes a protein with a coiled-coil domain in its central region that is required for the leptotene-zygotene transition during rice meiosis. To gain more insight into the role of OsAM1 in rice meiosis and identify additional meiosis-specific genes, we characterized the transcriptomes of young panicles of Osam1 mutant and wild-type rice plants using RNA-Seq combined with bioinformatic and statistical analyses. As a result, a total of 25,750 and 28,455 genes were expressed in young panicles of wild-type and Osam1 mutant plants, respectively, and 4,400 differentially expressed genes (DEGs; log2 Ratio ≥ 1, FDR ≤ 0.05) were identified. Of these DEGs, four known rice meiosis-specific genes were detected, and 22 new putative meiosis-related genes were found by mapping these DEGs to reference biological pathways in the KEGG database. We identified eight additional well-conserved OsAM1-responsive rice meiotic genes by comparing our RNA-Seq data with known meiotic genes in Arabidopsis and fission yeast. PMID:26394329

  16. Canned rice products as Philippine military food ration.

    PubMed

    Azanza, Maria Patricia V

    2003-05-01

    Canned prototypes of rice (CR) and rice meal with pork sausage (CRM) were developed as military food ration models for evaluation by personnel in the Bonifacio Naval Station, Fort Bonifacio, Makati, Philippines. The prototypes were produced based on the assumption that a serving size equivalent to 400 g cooked rice and a meat-based viand using a 1:4 (wt/wt) viand to rice ratio was adequate as a single-serve meal for a typical Philippine military personnel. The CR and CRM prototypes were low acid products with pH values of 4.9 and 5.5, respectively. The processed rice portions of the prototypes showed about 200% volume and weight increases, moderate clumpiness and low percentage breakage. More than 90% of the respondents agreed that CR and CRM were suitable military food rations. Majority of the panelists indicated preference for meat-based and poultry-based viands. Bulk and weight portativity problems, however, were raised with the 400 g serving size of cooked products in cans. PMID:12775372

  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. 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.

  20. 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...

  1. Efficacy of bacillus biocontrol agents for management of sheath blight and narrow brown leaf spot in organic rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic rice production has significantly increased in the U. S. over the last decade. Growers lack effective tools to manage sheath blight, caused by Rhizoctonia solani, and narrow brown leaf spot (NBLS), caused by Cercospora janseana, two major diseases affecting organic rice production. An experi...

  2. 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...

  3. Enhanced rice production but greatly reduced carbon emission following biochar amendment in a metal-polluted rice paddy.

    PubMed

    Zhang, Afeng; Bian, Rongjun; Li, Lianqing; Wang, Xudong; Zhao, Ying; Hussain, Qaiser; Pan, Genxing

    2015-12-01

    Soil amendment of biochar (BSA) had been shown effective for mitigating greenhouse gas (GHG) emission and alleviating metal stress to plants and microbes in soil. It has not yet been addressed if biochar exerts synergy effects on crop production, GHG emission, and microbial activity in metal-polluted soils. In a field experiment, biochar was amended at sequential rates at 0, 10, 20, and 40 t ha(-1), respectively, in a cadmium- and lead-contaminated rice paddy from the Tai lake Plain, China, before rice cropping in 2010. Fluxes of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored using a static chamber method during the whole rice growing season (WRGS) of 2011. BSA significantly reduced soil CaCl2 extractable pool of Cd, and DTPA extractable pool of Cd and Pb. As compared to control, soil CO2 emission under BSA was observed to have no change at 10 t ha(-1) but decreased by 16-24% at 20 and 40 t ha(-1). In a similar trend, BSA at 20 and 40 t ha(-1) increased rice yield by 25-26% and thus enhanced ecosystem CO2 sequestration by 47-55% over the control. Seasonal total N2O emission was reduced by 7.1, 30.7, and 48.6% under BSA at 10, 20, and 40 t ha(-1), respectively. Overall, a net reduction in greenhouse gas balance (NGHGB) by 53.9-62.8% and in greenhouse gas intensity (GHGI) by 14.3-28.6% was observed following BSA at 20 and 40 t ha(-1). The present study suggested a great potential of biochar to enhancing grain yield while reducing carbon emission in metal-polluted rice paddies. PMID:26213131

  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. LABA1, a Domestication Gene Associated with Long, Barbed Awns in Wild Rice[OPEN

    PubMed Central

    Hua, Lei; Wang, Diane R.; Tan, Lubin; Fu, Yongcai; Liu, Fengxia; Xiao, Langtao; Zhu, Zuofeng; Fu, Qiang; Sun, Xianyou; Gu, Ping; Cai, Hongwei; McCouch, Susan R.; Sun, Chuanqing

    2015-01-01

    Common wild rice (Oryza rufipogon), the wild relative of Asian cultivated rice (Oryza sativa), flaunts long, barbed awns, which are necessary for efficient propagation and dissemination of seeds. By contrast, O. sativa cultivars have been selected to be awnless or to harbor short, barbless awns, which facilitate seed processing and storage. The transition from long, barbed awns to short, barbless awns was a crucial event in rice domestication. Here, we show that the presence of long, barbed awns in wild rice is controlled by a major gene on chromosome 4, LONG AND BARBED AWN1 (LABA1), which encodes a cytokinin-activating enzyme. A frame-shift deletion in LABA1 of cultivated rice reduces the cytokinin concentration in awn primordia, disrupting barb formation and awn elongation. Sequencing analysis demonstrated low nucleotide diversity and a selective sweep encompassing an ∼800-kb region around the derived laba1 allele in cultivated rice. Haplotype analysis revealed that the laba1 allele originated in the japonica subspecies and moved into the indica gene pool via introgression, suggesting that humans selected for this locus in early rice domestication. Identification of LABA1 provides new insights into rice domestication and also sheds light on the molecular mechanism underlying awn development. PMID:26082172

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  8. LABA1, a Domestication Gene Associated with Long, Barbed Awns in Wild Rice.

    PubMed

    Hua, Lei; Wang, Diane R; Tan, Lubin; Fu, Yongcai; Liu, Fengxia; Xiao, Langtao; Zhu, Zuofeng; Fu, Qiang; Sun, Xianyou; Gu, Ping; Cai, Hongwei; McCouch, Susan R; Sun, Chuanqing

    2015-07-01

    Common wild rice (Oryza rufipogon), the wild relative of Asian cultivated rice (Oryza sativa), flaunts long, barbed awns, which are necessary for efficient propagation and dissemination of seeds. By contrast, O. sativa cultivars have been selected to be awnless or to harbor short, barbless awns, which facilitate seed processing and storage. The transition from long, barbed awns to short, barbless awns was a crucial event in rice domestication. Here, we show that the presence of long, barbed awns in wild rice is controlled by a major gene on chromosome 4, LONG AND BARBED AWN1 (LABA1), which encodes a cytokinin-activating enzyme. A frame-shift deletion in LABA1 of cultivated rice reduces the cytokinin concentration in awn primordia, disrupting barb formation and awn elongation. Sequencing analysis demonstrated low nucleotide diversity and a selective sweep encompassing an ∼800-kb region around the derived laba1 allele in cultivated rice. Haplotype analysis revealed that the laba1 allele originated in the japonica subspecies and moved into the indica gene pool via introgression, suggesting that humans selected for this locus in early rice domestication. Identification of LABA1 provides new insights into rice domestication and also sheds light on the molecular mechanism underlying awn development. PMID:26082172

  9. 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 370 km (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

  10. A rice membrane calcium-dependent protein kinase is induced by gibberellin.

    PubMed Central

    Abo-el-Saad, M; Wu, R

    1995-01-01

    A rice (Oryza sativa) seed plasma-membrane calcium-dependent serine/threonine protein kinase (CDPK) has been partially purified. Comparing results in seeds that were treated with and without the plant hormone gibberellin (GA) for 10 min showed that rice CDPK was highly induced by GA. After separating solubilized membrane proteins by sodium dodecyl sulfate-gel electrophoresis, followed by renaturation, a radiolabeled phosphoprotein band of approximately 58 kD was detected, and it was apparently produced by autophosphorylation. There are five aspects of the rice CDPK that show similarity to mammalian protein kinase C (PKC) and to other plant CDPKs: (a) Histone IIIS and PKC peptide-ser25 (19-31) are phosphorylated by rice CDPK. (b) The phosphorylation reaction is strictly dependent on calcium. (c) The activity of the rice CDPK is inhibited by either staurosporine or the PKC inhibitory peptide (19-36). (d) Addition of calmodulin has no effect on the activity of the enzyme; however, the CDPK is inhibited by the calmodulin antagonists trifluoperazine and W-7. (e) The rice CDPK reacts with a mammalian anti-PKC antibody in immunoblotting analysis. However, there is one major difference between the rice CDPK and other CDPKs: the rice CDPK is induced by GA, whereas no mammalian PKC or other plant CDPKs are known to be induced by any hormone. PMID:7610167

  11. 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

  12. Facile fabrication of rice husk based silicon dioxide nanospheres loaded with silver nanoparticles as a rice antibacterial agent.

    PubMed

    Cui, Jianghu; Liang, You; Yang, Desong; Liu, Yingliang

    2016-01-01

    Bacterial leaf blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major disease of rice, leading to reduction in production by 10-50%. In order to control this disease, various chemical bactericides have been used. Wide and prolonged application of chemical bactericides resulted in the resistant strain of Xoo that was isolated from rice. To address this problem, we were searching for an environmentally friendly alternative to the commonly used chemical bactericides. In this work, we demonstrate that silicon dioxide nanospheres loaded with silver nanoparticles (SiO2-Ag) can be prepared by using rice husk as base material precursor. The results of the antibacterial tests showed that SiO2-Ag composites displayed antibacterial activity against Xoo. At cellular level, the cell wall/membrane was damaged and intercellular contents were leaked out by slow-releasing of silver ions from SiO2-Ag composites. At molecular level, this composite induced reactive oxygen species production and inhibited DNA replication. Based on the results above, we proposed the potential antibacterial mechanism of SiO2-Ag composites. Moreover, the cytotoxicity assay indicated that the composites showed mild toxicity with rice cells. Thus, this work provided a new strategy to develop biocide derived from residual biomass. PMID:26888152

  13. Evolution of Compatibility Range in the Rice-Magnaporthe oryzae System: An Uneven Distribution of R Genes Between Rice Subspecies.

    PubMed

    Gallet, Romain; Fontaine, Colin; Bonnot, François; Milazzo, Joëlle; Tertois, Christophe; Adreit, Henri; Ravigné, Virginie; Fournier, Elisabeth; Tharreau, Didier

    2016-04-01

    Efficient strategies for limiting the impact of pathogens on crops require a good understanding of the factors underlying the evolution of compatibility range for the pathogens and host plants, i.e., the set of host genotypes that a particular pathogen genotype can infect and the set of pathogen genotypes that can infect a particular host genotype. Until now, little is known about the evolutionary and ecological factors driving compatibility ranges in systems implicating crop plants. We studied the evolution of host and pathogen compatibility ranges for rice blast disease, which is caused by the ascomycete Magnaporthe oryzae. We challenged 61 rice varieties from three rice subspecies with 31 strains of M. oryzae collected worldwide from all major known genetic groups. We determined the compatibility range of each plant variety and pathogen genotype and the severity of each plant-pathogen interaction. Compatibility ranges differed between rice subspecies, with the most resistant subspecies selecting for pathogens with broader compatibility ranges and the least resistant subspecies selecting for pathogens with narrower compatibility ranges. These results are consistent with a nested distribution of R genes between rice subspecies. PMID:26667186

  14. Facile fabrication of rice husk based silicon dioxide nanospheres loaded with silver nanoparticles as a rice antibacterial agent

    PubMed Central

    Cui, Jianghu; Liang, You; Yang, Desong; Liu, Yingliang

    2016-01-01

    Bacterial leaf blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major disease of rice, leading to reduction in production by 10–50%. In order to control this disease, various chemical bactericides have been used. Wide and prolonged application of chemical bactericides resulted in the resistant strain of Xoo that was isolated from rice. To address this problem, we were searching for an environmentally friendly alternative to the commonly used chemical bactericides. In this work, we demonstrate that silicon dioxide nanospheres loaded with silver nanoparticles (SiO2-Ag) can be prepared by using rice husk as base material precursor. The results of the antibacterial tests showed that SiO2-Ag composites displayed antibacterial activity against Xoo. At cellular level, the cell wall/membrane was damaged and intercellular contents were leaked out by slow-releasing of silver ions from SiO2-Ag composites. At molecular level, this composite induced reactive oxygen species production and inhibited DNA replication. Based on the results above, we proposed the potential antibacterial mechanism of SiO2-Ag composites. Moreover, the cytotoxicity assay indicated that the composites showed mild toxicity with rice cells. Thus, this work provided a new strategy to develop biocide derived from residual biomass. PMID:26888152

  15. 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 OsPR10α 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

  16. 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

  17. Emergy and ecosystem complexity

    NASA Astrophysics Data System (ADS)

    Ulgiati, Sergio; Brown, Mark T.

    2009-01-01

    The question "What drives complexity?" is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles explain much of what is observed, including energy degradation according to the laws of thermodynamics. Emergy, a quantitative measure of the global environmental work supporting ecosystem dynamics, is used here in order to provide a deeper understanding of complexity growth and decline in ecosystems. Ecosystem complexity is discussed in this paper in relation to changes in structure, organization and functional capacity, as explained by changes in emergy, empower, and transformity.

  18. Syrtis Major

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows from Nili Patera, a Martian 'caldera.' A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives!

  19. 40 CFR Table 1b to Subpart Zzzz of... - Operating Limitations for Existing, New, and Reconstructed SI 4SRB Stationary RICE >500 HP...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and not using NSCR. 1 Sources can petition the Administrator pursuant to the requirements of 40 CFR 63..., New, and Reconstructed SI 4SRB Stationary RICE >500 HP Located at a Major Source of HAP Emissions 1b... Limitations for Existing, New, and Reconstructed SI 4SRB Stationary RICE >500 HP Located at a Major Source...

  20. 40 CFR Table 1b to Subpart Zzzz of... - Operating Limitations for Existing, New, and Reconstructed SI 4SRB Stationary RICE >500 HP...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and not using NSCR. 1 Sources can petition the Administrator pursuant to the requirements of 40 CFR 63..., New, and Reconstructed SI 4SRB Stationary RICE >500 HP Located at a Major Source of HAP Emissions 1b... Limitations for Existing, New, and Reconstructed SI 4SRB Stationary RICE >500 HP Located at a Major Source...

  1. 40 CFR Table 2b to Subpart Zzzz of... - Operating Limitations for New and Reconstructed 2SLB and Compression Ignition Stationary RICE...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements of 40 CFR 63.8(g) for a different temperature range. ... Reconstructed 2SLB and Compression Ignition Stationary RICE >500 HP Located at a Major Source of HAP Emissions, New and Reconstructed 4SLB Stationary RICE â¥250 HP Located at a Major Source of HAP...

  2. 40 CFR Table 2b to Subpart Zzzz of... - Operating Limitations for New and Reconstructed 2SLB and CI Stationary RICE >500 HP Located at a...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pursuant to the requirements of 40 CFR 63.8(f) for a different temperature range. ... Reconstructed 2SLB and CI Stationary RICE >500 HP Located at a Major Source of HAP Emissions, New and Reconstructed 4SLB Stationary RICE â¥250 HP Located at a Major Source of HAP Emissions, Existing CI...

  3. 40 CFR Table 2b to Subpart Zzzz of... - Operating Limitations for New and Reconstructed 2SLB and CI Stationary RICE >500 HP Located at a...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pursuant to the requirements of 40 CFR 63.8(f) for a different temperature range. ... Reconstructed 2SLB and CI Stationary RICE >500 HP Located at a Major Source of HAP Emissions, New and Reconstructed 4SLB Stationary RICE â¥250 HP Located at a Major Source of HAP Emissions, Existing CI...

  4. 40 CFR Table 2b to Subpart Zzzz of... - Operating Limitations for New and Reconstructed 2SLB and Compression Ignition Stationary RICE...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements of 40 CFR 63.8(g) for a different temperature range. ... Reconstructed 2SLB and Compression Ignition Stationary RICE >500 HP Located at a Major Source of HAP Emissions, New and Reconstructed 4SLB Stationary RICE â¥250 HP Located at a Major Source of HAP...

  5. Soil Incorporation of Silica-Rich Rice Husk Decreases Inorganic Arsenic in Rice Grain.

    PubMed

    Seyfferth, Angelia L; Morris, Andrew H; Gill, Rattandeep; Kearns, Kelli A; Mann, Jessica N; Paukett, Michelle; Leskanic, Corey

    2016-05-18

    Arsenic decreases rice yield, and inorganic grain As threatens human health; thus, strategies to decrease rice As are critically needed. Increased plant-available silica (Si) can decrease rice As, yet the source of Si matters. Rice husk, an underutilized and Si-rich byproduct of rice production that contains less labile C and an order of magnitude less As than rice straw, may be an economically viable Si resource to decrease rice As, yet the impact of rice husk incorporation on As in the rice-soil nexus has not been reported. This proof-of-concept study shows that rice husk incorporation to soil (1% w/w) decreases inorganic grain As by 25-50% without negatively affecting grain Cd, yield, or dissolved CH4 levels. Rice husk is a critical yet perhaps overlooked resource to improve soil quality through enhanced nutrient availability and attenuate human health risks through consumption of As-laden grain. PMID:27109244

  6. Syrtis Major

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 6 June 2002) The Science This image, located near the equator and 288W (72E), is near the southern edge of a low, broad volcanic feature called Syrtis Major. A close look at this image reveals a wrinkly texture that indicates a very rough surface that is associated with the lava flows that cover this region. On a larger scale, there are numerous bright streaks that trail topographic features such as craters. These bright streaks are in the wind shadows of the craters where dust that settles onto the surface is not as easily scoured away. It is important to note that these streaks are only bright in a relative sense to the surrounding image. Syrtis Major is one of the darkest regions on Mars and it is as dark as fresh basalt flows or dunes are on Earth. The Story Cool! It almost looks as if nature has 'painted' comets on the surface of Mars, using craters as comet cores and dust as streaky tails. Of course, that's just an illusion. As in many areas of Mars, the wind is behind the creation of such fantastic landforms. The natural phenomenon seen here gives this particular surface of Mars a very dynamic, fast-moving, almost luminous 'cosmic personality.' The bright, powdery-looking streaks of dust are in the 'wind shadows' of craters, where dust that settles onto the surface is not as easily scoured away. That's because the wind moves across the land in a particular direction, and a raised surface like the rim of a crater 'protects' dust from being completely blown away on the other side. The raised landforms basically act as a buffer. From the streaks seen above, you can tell the wind was blowing in a northeast to southwest direction. Why are the streaks so bright? Because they contrast with the really dark underlying terrain in this volcanic area of Mars. Syrtis Major is one of the darkest regions on Mars because it is made of basalt. Basalt is typically dark gray or black, and forms when a certain type of molten lava cools. The meaning of the word basalt has been traced back to an ancient Ethiopian word 'basal,' which means 'a rock from which you can obtain iron.' That must have made it a very desired material with ancient Earth civilizations long ago. Basalt is actually one of the most abundant types of rock found on Earth. Most of the volcanic islands in the ocean are made of basalt, including the large shield volcano of Mauna Loa, Hawaii, which is often compared to Martian shield volcanoes. Shield volcanoes don't have high, steep, mountain-like sides, but are instead low and broad humps upon the surface. They're created when highly fluid, molten-basalt flows spread out over wide areas. Over several millennia of basaltic layering upon layering, these volcanoes can reach massive sizes like the ones seen on Mars. You can see the wrinkly texture of dark lava flows (now hard and cool) in the above image beneath the brighter dust.

  7. Rice scene radiation research plan

    NASA Technical Reports Server (NTRS)

    Heilman, J.

    1982-01-01

    Data requirements, tasks to be accomplished, and the technical approaches to be used in identifying the characteristics of rice for crop inventories are listed as well as methods for estimating crop development and assessing its conditions.

  8. For Consumers: Seven Things Pregnant Women and Parents Need to Know About Arsenic in Rice and Rice Cereal

    MedlinePlus

    ... and Parents Need to Know About Arsenic in Rice and Rice Cereal Share Tweet Linkedin Pin it More sharing ... present, it’s inorganic. 2. What about arsenic in rice? Rice is a staple of the global diet, ...

  9. 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

  10. Jasmonic acid and salicylic acid activate a common defense system in rice

    PubMed Central

    Tamaoki, Daisuke; Seo, Shigemi; Yamada, Shoko; Kano, Akihito; Miyamoto, Ayumi; Shishido, Hodaka; Miyoshi, Seika; Taniguchi, Shiduku; Akimitsu, Kazuya; Gomi, Kenji

    2013-01-01

    Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice. PMID:23518581

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. 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...

  13. Kennedy at Rice University

    NASA Technical Reports Server (NTRS)

    1962-01-01

    President Kennedy speaks before a crowd of 35,000 people at Rice University in the football field. The following are excerpts from his speech. ' ...We set sail on his new sea because there is a new knowledge to begained, and new rights to be won, and they must be won and used for the progress of all people. Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. But I do say space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made with extending his wirt around this globe of ours. There is no strife, no prejudice, no national conflict in outer space as yet. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain? Why 35 years ago why fly the Atlantic? Why does Rice play Texas? We choose to go to the Moon, we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one in which we attend to win, and the others , too.'

  14. Kennedy at Rice University

    NASA Technical Reports Server (NTRS)

    1962-01-01

    President Kennedy speaks before a crowd of 35,000 people at Rice University in the football field. The following are excerpts from his speech. ' ...We set sail on his new sea because there is a new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people. ...Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war. But I do say space can be explored and mastered without feeding the fires of war, without repeating the mistakes that man has made with extending his writ around this globe of ours. ...There is no strife, no prejudice, no national conflict in outer space as yet. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountian? Why - 35 years ago - why fly the Atlantic? Why does Rice play Texas? We choose to go to the Moon, we choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one in which we intend to win, and the others too.'

  15. 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.

  16. Expansins in deepwater rice internodes

    SciTech Connect

    Cho, Hyung-Taeg; Kende, H.

    1997-04-01

    Cell walls of deepwater rice internodes undergo long-term extension (creep) when placed under tension in acidic buffers. This is indicative of the action of the cell wall-loosening protein expansion. Wall extension had a pH optimum of around 4.0 and was abolished by boiling. Acid-induced extension of boiled cell walls could be reconstituted by addition of salt-extracted rice or cucumber cell wall proteins. Cucumber expansion antibody recognized a single protein band of 24.5-kD apparent molecular mass on immunoblots of rice cell wall proteins. Expansions were partially purified by concanavalin A affinity chromatography and sulfopropyl (SP) cation-exchange chromatography. The latter yielded two peaks with extension activity (SP20 and SP29), and immunoblot analysis showed that both of these active fractions contained expansion of 24.5-kD molecular mass. The N-terminal amino acid sequence of SP20 expansion is identical to that deduced from the rice expansion cDNA Os-EXP1. The N-terminal amino acid sequence of SP29 expansion matches that deduced from the rice expansion cDNA Os-EXP2 in six of eight amino acids. Our results show that two expansions occur in the cell walls of rice internodes and that they may mediate acid-induced wall extension.

  17. OsKAT2 is the prevailing functional inward rectifier potassium channels in rice guard cell

    PubMed Central

    Hwang, Hyunsik; Yoon, Jin-Young; Cho, Hana; Kim, Beom-Gi

    2013-01-01

    AtKAT1 plays roles as a major channel to uptake K+ in guard cell when stomata open in dicot model plant Arabidopsis. In a recent publication, we isolated 3 KAT-like potassium channels in rice. We expressed them in CHO cell to identify electrophysiological characteristics of the channels. OsKAT2 showed much bigger inwardly rectifying potassium channel activities among them. The histochemical X-glu staining of transgenic rice leaf blades expressing β-glucuronidase fused with OsKAT2 promoter showed that the OsKAT2 is dominantly expressed in rice guard cell. These findings indicate that OsKAT2 may be a functional ortholog of AtKAT1 in rice. Thus this gene will be the prime target for engineering the guard cell movement to improve drought tolerance in monocot plants, including most major crops. PMID:24103920

  18. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China.

    PubMed

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2016-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg(-)¹, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

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

    PubMed

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

    2015-11-17

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

  20. Impact of phytic acid on nutrient bioaccessibility and antioxidant properties of dehusked rice.

    PubMed

    Lee, H H; Loh, S P; Bong, C F J; Sarbini, S R; Yiu, P H

    2015-12-01

    Whole grains consumption promotes health benefits, but demonstrates controversial impacts from phytic acid in meeting requirements of good health. Therefore, this study was aimed to determine the nutrient bioaccessibility and antioxidant properties of rice cultivars named "Adan" or "Bario" and deduce the nutritional impact of phytic acid. Majority of the dehusked rice in the collection showed an acceptable level of in-vitro starch digestibility and in-vitro protein digestibility, but were poor in antioxidant properties and bioaccessibility of minerals (Ca, Fe and Zn). The drawbacks identified in the rice cultivars were due to relatively high phytic acid content (2420.6 ± 94.6 mg/100 g) and low phenolic content (152.39 ± 18.84 μg GAE/g). The relationship between phytic acid content and mineral bioaccessibility was strongest in calcium (r = 0.60), followed by iron (r = 0.40) and zinc (r = 0.27). Phytic acid content did not significantly correlate with in-vitro starch digestibility and in-vitro protein digestibility but showed a weak relationship with antioxidant properties. These suggest that phytic acid could significantly impair the mineral bioaccessibility of dehusked rice, and also act as an important antioxidant in non-pigmented rice. Bario rice cultivars offered dehusked rice with wide range of in-vitro digestibility of starch and protein, and also pigmented rice as a good source of antioxidants. However, there is a need to reduce phytic acid content in dehusked rice for improved mineral bioaccessibility among Bario rice cultivars. PMID:26604353

  1. Heavy Metal Pollution in a Soil-Rice System in the Yangtze River Region of China

    PubMed Central

    Liu, Zhouping; Zhang, Qiaofen; Han, Tiqian; Ding, Yanfei; Sun, Junwei; Wang, Feijuan; Zhu, Cheng

    2015-01-01

    Heavy metals are regarded as toxic trace elements in the environment. Heavy metal pollution in soil or rice grains is of increasing concern. In this study, 101 pairs of soil and rice samples were collected from the major rice-producing areas along the Yangtze River in China. The soil properties and heavy metal (i.e., Cd, Hg, Pb and Cr) concentrations in the soil and rice grains were analyzed to evaluate the heavy metal accumulation characteristics of the soil-rice systems. The results showed that the Cd, Hg, Pb and Cr concentrations in the soil ranged from 0.10 to 4.64, 0.01 to 1.46, 7.64 to 127.56, and 13.52 to 231.02 mg·kg−1, respectively. Approximately 37%, 16%, 60% and 70% of the rice grain samples were polluted by Cd, Hg, Pb, and Cr, respectively. The degree of heavy metal contamination in the soil-rice systems exhibited a regional variation. The interactions among the heavy metal elements may also influence the migration and accumulation of heavy metals in soil or paddy rice. The accumulation of heavy metals in soil and rice grains is related to a certain extent to the pH and soil organic matter (SOM). This study provides useful information regarding heavy metal accumulation in soil to support the safe production of rice in China. The findings from this study also provide a robust scientific basis for risk assessments regarding ecological protection and food safety. PMID:26703698

  2. Regime shifts and resilience in China's coastal ecosystems.

    PubMed

    Zhang, Ke

    2016-02-01

    Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. China's coastal ecosystems have experienced substantial deterioration within the past decades, at a scale and speed the world has never seen before. Yet, information about this coastal ecosystem change from a dynamics perspective is quite limited. In this review, I synthesize existing information on coastal ecosystem regime shifts in China and discuss their interactions and cascading effects. The accumulation of regime shifts in China's coastal ecosystems suggests that the desired system resilience has been profoundly eroded, increasing the potential of abrupt shifts to undesirable states at a larger scale, especially given multiple escalating pressures. Policy and management strategies need to incorporate resilience approaches in order to cope with future challenges and avoid major losses in China's coastal ecosystem services. PMID:26286204

  3. 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.

  4. 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…

  5. 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

  6. 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...

  7. 75 FR 56911 - Request for Public Comment on the United States Standards for Rough Rice, Brown Rice for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ..., Brown Rice for Processing, and Milled Rice standards were last revised in 1993 (58 FR 68015) and appear... Comment on the United States Standards for Rough Rice, Brown Rice for Processing, and Milled Rice AGENCY... Administration (GIPSA) is reviewing the United States Standards and grading procedures for Rough Rice, Brown...

  8. Metabolic engineering and profiling of rice with increased lysine.

    PubMed

    Long, Xiaohang; Liu, Qiaoquan; Chan, Manling; Wang, Qing; Sun, Samuel S M

    2013-05-01

    Lysine (Lys) is the first limiting essential amino acid in rice, a stable food for half of the world population. Efforts, including genetic engineering, have not achieved a desirable level of Lys in rice. Here, we genetically engineered rice to increase Lys levels by expressing bacterial lysine feedback-insensitive aspartate kinase (AK) and dihydrodipicolinate synthase (DHPS) to enhance Lys biosynthesis; through RNA interference of rice lysine ketoglutaric acid reductase/saccharopine dehydropine dehydrogenase (LKR/SDH) to down-regulate its catabolism; and by combined expression of AK and DHPS and interference of LKR/SDH to achieve both metabolic effects. In these transgenic plants, free Lys levels increased up to ~12-fold in leaves and ~60-fold in seeds, substantially greater than the 2.5-fold increase in transgenic rice seeds reported by the only previous related study. To better understand the metabolic regulation of Lys accumulation in rice, metabolomic methods were employed to analyse the changes in metabolites of the Lys biosynthesis and catabolism pathways in leaves and seeds at different stages. Free Lys accumulation was mainly regulated by its biosynthesis in leaves and to a greater extent by catabolism in seeds. The transgenic plants did not show observable changes in plant growth and seed germination nor large changes in levels of asparagine (Asn) and glutamine (Gln) in leaves, which are the major amino acids transported into seeds. Although Lys was highly accumulated in leaves of certain transgenic lines, a corresponding higher Lys accumulation was not observed in seeds, suggesting that free Lys transport from leaves into seeds did not occur. PMID:23279104

  9. A Comprehensive Assessment of the Effects of Transgenic Cry1Ac/Cry1Ab Rice Huahui 1 on Adult Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae)

    PubMed Central

    Zhou, Xia; Guo, Yunling; Kong, Hua; Zuo, Jiao; Huang, Qixing; Jia, Ruizong; Guo, Anping; Xu, Lin

    2016-01-01

    Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae) is a widely distributed coleoptera predator in southern Asia in rice ecosystem, and adult M. discolor feed on both rice pollen and soft-bodied arthropods. Bitrophic bioassay and tritrophic bioassay were conducted to evaluate the potential impact of Cry1Ac/Cry1Ab-expressing rice Huahui 1 and its non-transgenic counterpart Minghui 63 on fitness parameters of adult M. discolor. The results showed that the survival, and fecundity of this beetle’ adults were not different when they fed on Bt rice or non-Bt rice pollen or Nilaparvata lugens (Stål) reared on Bt rice or non-Bt rice. Toxicity assessment to ensure M. discolor adults were not sensitive to Cry1Ab or Cry1Ac protein independent from the pollen background, M. discolor adults were fed with an artificial diet containing Cry1Ac, Cry1Ab or both protein approximately 10 times higher concentration than in Huahui 1 rice pollen. No difference was detected for any of the life-table parameters tested between Cry protein-containing and pure diet. Artificial diet containing E-64 (N-(trans-Epoxysuccinyl)-L-leucine 4-guanidinobutylamide) was included as a positive control. In contrast, the pre-oviposition and fecundity of M. discolor were significantly adversely affected by feeding on E-64-containing diet. In both bioassays, the uptakes of Cry protein by adult M. discolor were tested by ELISA measurements. These results indicated that adults of M. discolor are not affected by Cry1Ab- or Cry1Ac-expressing rice pollen and are not sensitive to Cry protein at concentrations exceeding the levels in rice pollen in Huahui1. This suggests that M. discolor adults would not be harmed by Cry1Ac/Cry1Ab rice if Bt rice Huahui 1 were commercialized. PMID:26914608

  10. A Comprehensive Assessment of the Effects of Transgenic Cry1Ac/Cry1Ab Rice Huahui 1 on Adult Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae).

    PubMed

    Zhou, Xia; Guo, Yunling; Kong, Hua; Zuo, Jiao; Huang, Qixing; Jia, Ruizong; Guo, Anping; Xu, Lin

    2016-01-01

    Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae) is a widely distributed coleoptera predator in southern Asia in rice ecosystem, and adult M. discolor feed on both rice pollen and soft-bodied arthropods. Bitrophic bioassay and tritrophic bioassay were conducted to evaluate the potential impact of Cry1Ac/Cry1Ab-expressing rice Huahui 1 and its non-transgenic counterpart Minghui 63 on fitness parameters of adult M. discolor. The results showed that the survival, and fecundity of this beetle' adults were not different when they fed on Bt rice or non-Bt rice pollen or Nilaparvata lugens (Stl) reared on Bt rice or non-Bt rice. Toxicity assessment to ensure M. discolor adults were not sensitive to Cry1Ab or Cry1Ac protein independent from the pollen background, M. discolor adults were fed with an artificial diet containing Cry1Ac, Cry1Ab or both protein approximately 10 times higher concentration than in Huahui 1 rice pollen. No difference was detected for any of the life-table parameters tested between Cry protein-containing and pure diet. Artificial diet containing E-64 (N-(trans-Epoxysuccinyl)-L-leucine 4-guanidinobutylamide) was included as a positive control. In contrast, the pre-oviposition and fecundity of M. discolor were significantly adversely affected by feeding on E-64-containing diet. In both bioassays, the uptakes of Cry protein by adult M. discolor were tested by ELISA measurements. These results indicated that adults of M. discolor are not affected by Cry1Ab- or Cry1Ac-expressing rice pollen and are not sensitive to Cry protein at concentrations exceeding the levels in rice pollen in Huahui1. This suggests that M. discolor adults would not be harmed by Cry1Ac/Cry1Ab rice if Bt rice Huahui 1 were commercialized. PMID:26914608

  11. Processing Conditions, Rice Properties, Health and Environment

    PubMed Central

    Roy, Poritosh; Orikasa, Takahiro; Okadome, Hiroshi; Nakamura, Nobutaka; Shiina, Takeo

    2011-01-01

    Rice is the staple food for nearly two-thirds of the world’s population. Food components and environmental load of rice depends on the rice form that is resulted by different processing conditions. Brown rice (BR), germinated brown rice (GBR) and partially-milled rice (PMR) contains more health beneficial food components compared to the well milled rice (WMR). Although the arsenic concentration in cooked rice depends on the cooking methods, parboiled rice (PBR) seems to be relatively prone to arsenic contamination compared to that of untreated rice, if contaminated water is used for parboiling and cooking. A change in consumption patterns from PBR to untreated rice (non-parboiled), and WMR to PMR or BR may conserve about 43–54 million tons of rice and reduce the risk from arsenic contamination in the arsenic prone area. This study also reveals that a change in rice consumption patterns not only supply more food components but also reduces environmental loads. A switch in production and consumption patterns would improve food security where food grains are scarce, and provide more health beneficial food components, may prevent some diseases and ease the burden on the Earth. However, motivation and awareness of the environment and health, and even a nominal incentive may require for a method switching which may help in building a sustainable society. PMID:21776212

  12. Molecular progress on the mapping and cloning of functional genes for blast disease in rice (Oryza sativa L.): current status and future considerations.

    PubMed

    Ashkani, S; Rafii, M Y; Shabanimofrad, M; Ghasemzadeh, A; Ravanfar, S A; Latif, M A

    2016-01-01

    Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes. PMID:25394538

  13. 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...

  14. The impact of planting date on management of the rice water weevil in Louisiana rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rice water weevil, Lissorhoptrus oryzophilus, is the most destructive insect pest of rice in the United States. Early planting of rice to avoid damaging infestations of the rice water weevil has long been suggested as a management tactic. A five-year study was conducted to characterize the influ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of different quality traits that make up the rice grain and obtain a full picture of rice quality demographics. Rice ...

  16. Molecular dynamics of interactions of rice with rice blast and sheath blight pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to develop the molecular strategies to control rice (Oryzae sativa) diseases, molecular interactions of rice with rice blast [Magnaporthe oryzae, formerly (Magnaporthe grisea] and sheath blight (Rhizoctonia solani) fungi were analyzed. The interaction of rice with M. oryzae follows a b...

  17. Agglomeration characteristics of silica sand-rice husk ash mixtures at elevated temperatures

    SciTech Connect

    Mansaray, K.G.; Ghaly, A.E.

    1998-08-01

    Rice husk, a major by-product of the rice milling process, can be a significant energy resource in rice producing countries because of its high energy content. Fluidized bed gasifiers have been proposed for the recovery of energy from rice husk. The major advantage of fluidized bed gasifiers over fixed bed gasifiers is the high mass and heat transfer capability due to very high percentage of inert bed material such as silica sand. In addition, the vigorous mixing and agitation of solid particles in fluidized beds promote a uniform temperature distribution and a high conversion efficiency. However, attempts to utilize rice husk as a feed in fluidized bed gasifiers have been unsuccessful because of the high ash content of rice husk that may result in the agglomeration of inert bed materials at high temperatures. In this work, the effect of rice husk ash content on the agglomeration characteristics of silica sand was investigated at various temperatures using a muffle furnace. A light microscope, an environmental scanning electron microscope, and an energy dispersive X-ray analyzer were used to characterize the structural changes and elemental makeup of the samples. There was no indication of agglomeration below 850 C, but at temperatures of 850--1,000 C the silica sand loosely agglomerated in the presence of rice husk ash at all levels of ash content. The effect was more pronounced at 1,000 C. The chemical interaction of the SiO{sub 2} and the low melting temperature mineral oxides present in notably low concentrations in rice husk ash, appeared to be the mechanism resulting in the formation of the loose agglomerates.

  18. A Historical Analysis of the Relationship Between Rice Production and PDSI Values in Sri Lanka

    NASA Astrophysics Data System (ADS)

    Jacobi, J. H.; Hornberger, G. M.

    2011-12-01

    As world population grows, there are ever increasing demands being placed on the food production systems throughout the world. Climate change is complicating these stressors even further through more frequent severe weather events. In the developing world, where there are fewer resources to mitigate the effects of climate change, the combination of these two factors can have drastic consequences. In Sri Lanka, farmers in major rice production areas of the country are already struggling to produce enough rice, a staple food of the local diet, and a severe wet or dry spell could be ruinous. Faced with a changing climate and a growing demand for rice, it is important to be able to anticipate how climatic changes will affect rice production. By examining how extreme wet and dry spells have historically affected rice production, decision makers may be better able to predict and prepare for potential food shortages. We conducted an analysis of historic temperature, precipitation, and rice production statistics in order to determine the effects of extreme wet and dry spells on rice production. We also created a timeline of major developments in Sri Lankan agriculture in order to compare effects on rice production due to changes in agricultural practices with meteorological changes. Historical temperature and precipitation data were used to calculate the Palmer Drought Severity Index (PDSI) for a number of stations distributed throughout the Mahaweli river basin. The basin, the largest in the country, contains three different climatic regions - dry, intermediate, and wet - that all receive different amounts of annual precipitation. The PDSI values were used to quantify drought and wetness during the Yala (April-September) and Maha (October-March) growing seasons. Analysis of historical PDSI values, agricultural advances, and rice production statistics shows great promise for anticipating and mitigating future food shortages.

  19. Limited surveillance of fumonisins in brown rice and wheat harvested in Japan.

    PubMed

    Kushiro, Masayo; Zheng, Yazhi; Nagata, Reiko; Nakagawa, Hiroyuki; Nagashima, Hitoshi

    2009-06-01

    Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which is a major contaminant of corn. However, there are sporadic reports of fumonisin contamination in wheat worldwide. The rice adherent fungus Gibberella fujikuroi is taxonomically closely related to F. verticillioides. Therefore, the potential risk of fumonisin contamination in rice and wheat is significant. Previously, a sensitive detection method utilizing liquid chromatography with tandem electrospray mass spectrometry (LC-ESI-MS-MS) was developed for the determination of fumonisins in brown rice. In the present study, the incidence of fumonisins in brown rice and wheat harvested in Japan was investigated using LC-ESI-MS-MS. Forty-eight rice samples and 47 wheat samples were screened and analyzed for the major B-type fumonisins: fumonisin B1 (FB1) and fumonisin B2 (FB2). About 1 kg of rice or wheat seed was divided into three subsamples, and 10 g from each subsample was used for the analysis. The limits of detection were 0.012 and 0.011 mg/kg for FBt and FB2, respectively, in rice samples and 0.010 and 0.008 mg/kg for FB1 and FB2, respectively, in wheat samples. The mean (standard deviation) recoveries of FB1 spiked at 0.50 mg/kg into toxin-free rice and wheat samples were 77.6 (4.2)% and 84.5 (3.1)%, respectively. One of the wheat samples was positive for FBt with a value greater than the limit of detection,but no fumonisin was found in any of the rice samples. This is the first report of fumonisins detected in Japanese wheat. PMID:19610350

  20. Laboratory and field assessments of prey-mediated effects of transgenic Bt rice on Ummeliata insecticeps (Araneida: Linyphiidae).

    PubMed

    Tian, J C; Liu, Z C; Chen, M; Chen, Y; Chen, X X; Peng, Y F; Hu, C; Ye, G Y

    2010-08-01

    One major concern regarding the release of Bt rice is its potential impact through tritrophic interactions on nontarget arthropods, especially natural enemies. We studied the effects of two Bt transgenic rice varieties, TT9- 3 and KMD1, expressing Cry1Ab/Cry1Ac and Cry1Ab, respectively, on a predatory ground spider [Ummeliata insecticeps (Bösenberg et Strand)] supplied with Bt rice-fed brown planthopper [Nilaparvata lugens (Stål)] nymphs. Although immunoassays confirmed that U. insecticeps ingested Bt insecticidal protein when supplied with Bt rice-fed N. lugens, no negative effects were found on its survival and development. Furthermore, the fecundity of U. insecticeps fed prey reared on Bt rice was not significantly different from that of those fed prey reared on non-Bt rice. A 3-yr field trial indicated that Bt rice did not significantly affect the population density of U. insecticeps in comparison with non-Bt rice. In conclusion, the Bt rice lines tested in this study had no adverse effects on the survival, developmental time, or fecundity of U. insecticeps in the laboratory or on population dynamics in the field. PMID:22127189

  1. 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

  2. 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

  3. GENE FLOW BETWEEN RED RICE AND RICE IN HERBICIDE RESISTANT RICE FIELDS: EVALUATING RISKS AND MANAGEMENT OPTIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imidazolinone (IMI)-resistant rice cultivars have been increasingly adopted in the southern U.S. since their initial introduction in 2002, largely due to the newly acquired control of red rice that is now possible in these systems. It is estimated that IMI rice is being grown on 20 to 25% of the ac...

  4. 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. Different responses of low grain-Cd-accumulating and high grain-Cd-accumulating rice cultivars to Cd stress.

    PubMed

    Wang, Feijuan; Wang, Min; Liu, Zhouping; Shi, Yan; Han, Tiqian; Ye, Yaoyao; Gong, Ning; Sun, Junwei; Zhu, Cheng

    2015-11-01

    Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars. PMID:26318143

  6. 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 μmol.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

  7. Comprehensive profiling of the rice ubiquitome reveals the significance of lysine ubiquitination in young leaves.

    PubMed

    Xie, Xin; Kang, Houxiang; Liu, Wende; Wang, Guo-Liang

    2015-05-01

    Protein ubiquitination is a major post-translational modification that regulates development, apoptosis, responses to environmental cues, and other processes in eukaryotes. Although several ubiquitinated proteins have been identified in rice, large-scale profiling of the rice ubiquitome has not been reported because of limitations in the current analytical methods. Here, we report the first rice ubiquitome, determined by combining highly sensitive immune affinity purification and high resolution LC-MS/MS. We identified 861 di-Gly-Lys-containing peptides in 464 proteins in rice leaf cells. Bioinformatic analyses of the ubiquitome identified a variety of cellular functions and diverse subcellular localizations for the ubiquitinated proteins, and also revealed seven putative ubiquitination motifs in rice. Proteins related to binding and catalytic activity were predicted to be the preferential targets of lysine ubiquitination. A protein interaction network and KEGG analysis indicated that a wide range of signaling and metabolic pathways are modulated by protein ubiquitination in rice. Our results demonstrate the usefulness of the significantly improved method for assaying proteome-wide ubiquitination in plants. The identification of the 464 ubiquitinated proteins in rice leaves provides a foundation for the analysis of the physiological roles of these ubiquitination-related proteins. PMID:25751157

  8. Genetic dissection of the biotic stress response using a genome-scale gene network for rice.

    PubMed

    Lee, Insuk; Seo, Young-Su; Coltrane, Dusica; Hwang, Sohyun; Oh, Taeyun; Marcotte, Edward M; Ronald, Pamela C

    2011-11-01

    Rice is a staple food for one-half the world's population and a model for other monocotyledonous species. Thus, efficient approaches for identifying key genes controlling simple or complex traits in rice have important biological, agricultural, and economic consequences. Here, we report on the construction of RiceNet, an experimentally tested genome-scale gene network for a monocotyledonous species. Many different datasets, derived from five different organisms including plants, animals, yeast, and humans, were evaluated, and 24 of the most useful were integrated into a statistical framework that allowed for the prediction of functional linkages between pairs of genes. Genes could be linked to traits by using guilt-by-association, predicting gene attributes on the basis of network neighbors. We applied RiceNet to an important agronomic trait, the biotic stress response. Using network guilt-by-association followed by focused protein-protein interaction assays, we identified and validated, in planta, two positive regulators, LOC_Os01g70580 (now Regulator of XA21; ROX1) and LOC_Os02g21510 (ROX2), and one negative regulator, LOC_Os06g12530 (ROX3). These proteins control resistance mediated by rice XA21, a pattern recognition receptor. We also showed that RiceNet can accurately predict gene function in another major monocotyledonous crop species, maize. RiceNet thus enables the identification of genes regulating important crop traits, facilitating engineering of pathways critical to crop productivity. PMID:22042862

  9. 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

  10. 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

  11. Identification of Low Postharvest Yellowing Rice Cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Postharvest yellowing (PHY), or stackburn, reduces the value of rice. The identification of a low PHY rice cultivar would be desirable for breeding purposes, as well as for understanding of the PHY phenomenon. A laboratory method was used to survey different cultivars of rice for their ability to ...

  12. New market opportunities for rice grains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding efforts for rice have been focusing on increasing yield and improving quality (milling yield and grain quality), while maintaining cooked rice sensory properties to meet consumer preferences. These breeding targets will no doubt continue as the main foci for the rice industry. However, the ...

  13. Rice bran stabilization using alternative techniques (abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Utilization of rice bran, a by-product of rice milling characterized with a high economic value, is severely restricted by the activity of endogenous enzymes which typically deteriorate the bran quality. There is a great need to develop alternative techniques for stabilizing rice bran and at the sam...

  14. U.S. Rice: Enhancing human health.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A vision of the U.S. rice industry is to improve human health through the development of germplasm and technologies for products that capture the unique nutritional benefits of the rice grain. This paper gives an overview of U.S. rice production and markets. New product trends and introductions in...

  15. Unraveling the secrets of rice wild species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rice wild species (Oryza spp.) genepool is a relatively untapped source of novel alleles for crop improvement. Several different accessions of rice wild species have been crossed as donor parents with several different Asian rice (O. sativa) cultivars, as the recurrent parent to develop mappi...

  16. Rice disease research in organic production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic rice production has increased significantly in the U. S. with 35,000 acres currently under production. Texas organic rice acreage has been increasing steadily over the last 10 years with acreage in 2009 reaching 16,000, accounting for approximately 10% of the total Texas rice acreage. Contro...

  17. Rice phytochemical identification and genetic diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole-grain rice, especially the dark color bran rice, contains high phenolic content and antioxidant capacity, which have potential in disease prevention. However, little information is available regarding the differences in phytochemical profiles of rice of different bran color. Studies indicated ...

  18. Is ALL Rice Bran Created Equal?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of whole grain rice is increasing in the U.S. This increase is likely due to increased consumer awareness of the importance of whole grains in the diet. Whole grain rice is superior nutritionally compared to milled rice because, except for carbohyrates, it contains more phytochemicals an...

  19. Understanding rice heterosis using deep sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterosis is a complex biological phenomenon where the offspring show better performance compared to the inbred parents. Although rice breeders have used heterosis in hybrid rice production for nearly 40 years, the genetic and molecular mechanism underlying the heterosis in rice is still poorly und...

  20. SHEATH BLIGHT RESISTANCE IN SOUTHERN RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sheath blight is a serious fungal disease problem in southern US rice production, making it necessary for rice farmers to diligently use fungicides for its control. There are no long grain rice varieties adapted to commercial production in the southern US that have adequate resistance to sheath bli...

  1. Habitat scale mapping of fisheries ecosystem services values in estuaries

    EPA Science Inventory

    Little is known about the variability of ecosystem service values at spatial scales most relevant to local decision makers. Competing definitions of ecosystem services, the paucity of ecological and economic information and the lack of standardization in methodology are major ob...

  2. 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...

  3. Student Ecosystems Problem Solving Using Computer Simulation.

    ERIC Educational Resources Information Center

    Howse, Melissa A.

    The purpose of this study was to determine the procedural knowledge brought to, and created within, a pond ecology simulation by students. Environmental Decision Making (EDM) is an ecosystems modeling tool that allows users to pose their own problems and seek satisfying solutions. Of specific interest was the performance of biology majors who had…

  4. Relevance of antarctic microbial ecosystems to exobiology

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.

    1993-01-01

    Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.

  5. 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 (19842010), 92,158 women from the Nurses Health Study II (19912011), and 42,170 men from the Health Professionals Follow-Up Study (19862010)] 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

  6. Comparative Morphophysiological Analyses and Molecular Profiling Reveal Pi-Efficient Strategies of a Traditional Rice Genotype

    PubMed Central

    Mehra, Poonam; Pandey, Bipin K.; Giri, Jitender

    2016-01-01

    Phosphate (Pi) deficiency severely affects crop yield. Modern high yielding rice genotypes are sensitive to Pi deficiency whereas traditional rice genotypes are naturally compatible with low Pi ecosystems. However, the underlying molecular mechanisms for low Pi tolerance in traditional genotypes remain largely elusive. To delineate the molecular mechanisms for low Pi tolerance, two contrasting rice genotypes, Dular (low Pi tolerant), and PB1 (low Pi sensitive), have been selected. Comparative morphophysiological, global transcriptome and lipidome analyses of root and shoot tissues of both genotypes grown under Pi deficient and sufficient conditions revealed potential low Pi tolerance mechanisms of the traditional genotype. Most of the genes associated with enhanced internal Pi utilization (phospholipid remobilization) and modulation of root system architecture (RSA) were highly induced in the traditional rice genotype, Dular. Higher reserves of phospholipids and greater accumulation of galactolipids under low Pi in Dular indicated it has more efficient Pi utilization. Furthermore, Dular also maintained greater root growth than PB1 under low Pi, resulting in larger root surface area due to increased lateral root density and root hair length. Genes involved in enhanced low Pi tolerance of the traditional genotype can be exploited to improve the low Pi tolerance of modern high yielding rice cultivars. PMID:26779218

  7. Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China.

    PubMed

    Zong, Y; Chen, Z; Innes, J B; Chen, C; Wang, Z; Wang, H

    2007-09-27

    The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr bp). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by 'bunding' to maintain crop yields. The site's exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr bp. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment. PMID:17898767

  8. A comparison of methane emissions following rice paddies conversion to crab-fish farming wetlands in southeast China.

    PubMed

    Hu, Zhiqiang; Wu, Shuang; Ji, Cheng; Zou, Jianwen; Zhou, Quansuo; Liu, Shuwei

    2016-01-01

    Rice paddies and aquaculture wetlands are typical agricultural wetlands that constitute one of the important sources of atmospheric methane (CH4). Traditional transplanted rice paddies have been experiencing conversion to pond aquaculture wetlands for pursuing higher economic benefits over the past decades in southeast China. A parallel field experiment was carried out to compare CH4 emissions from a transplanted rice paddy and its converted crab-fish farming wetland in southeast China. Over the rice-growing season, CH4 fluxes averaged 1.86 mg m(-2) h(-1) from rice paddies, and 1.14 and 0.50 mg m(-2) h(-1) for the treatments with or without aquatic vegetation present in the crab-fish farming wetlands, respectively. When averaged across the treatments, seasonal CH4 emissions from crab-fish framing wetlands were 52 % lower than those from rice paddies. The CH4 fluxes were negatively related to water dissolved oxygen (DO) concentration but positively related to soil/sediment dissolved organic carbon (DOC) content in crab-fish farming wetlands. Dependence of CH4 fluxes on DO or DOC was intensified by the aquatic vegetation presence. By extrapolating the present CH4 emission rate with the current rice paddy-converted aquaculture cultivation area, the seasonal CH4 emissions from inland aquaculture wetlands during the critical farming stage (20 June to 18 October) were estimated to be 33.6 Gg ha(-1) in southeast China in 2012. Rice paddies conversion to crab-fish farming wetlands might have reduced CH4 emissions by 22-54 % in mainland China. Results of this study suggest that the conversion of transplanted rice paddies to crab-fish aquaculture wetlands for higher economic benefits would also lead to a lower ecosystem CH4 release rate. PMID:26374545

  9. Wetland management and rice farming strategies to decrease methylmercury bioaccumulation and loads from the Cosumnes River Preserve, California

    USGS Publications Warehouse

    Eagles-Smith, Collin A.; Ackerman, Joshua T.; Fleck, Jacob; Windham-Myers, Lisamarie; McQuillen, Harry; Heim, Wes

    2014-01-01

    We evaluated mercury (Hg) concentrations in caged fish (deployed for 30 days) and water from agricultural wetland (rice fields), managed wetland, slough, and river habitats in the Cosumnes River Preserve, California. We also implemented experimental hydrological regimes on managed wetlands and post-harvest rice straw management techniques on rice fields in order to evaluate potential Best Management Practices to decrease methylmercury bioaccumulation within wetlands and loads to the Sacramento-San Joaquin River Delta. Total Hg concentrations in caged fish were twice as high in rice fields as in managed wetland, slough, or riverine habitats, including seasonal managed wetlands subjected to identical hydrological regimes. Caged fish Hg concentrations also differed among managed wetland treatments and post-harvest rice straw treatments. Specifically, Hg concentrations in caged fish decreased from inlets to outlets in seasonal managed wetlands with either a single (fall-only) or dual (fall and spring) drawdown and flood-up events, whereas Hg concentrations increased slightly from inlets to outlets in permanent managed wetlands. In rice fields, experimental post-harvest straw management did not decrease Hg concentrations in caged fish. In fact, in fields in which rice straw was chopped and either disked into the soil or baled and removed from the fields, fish Hg concentrations increased from inlets to outlets and were higher than Hg concentrations in fish from rice fields subjected to the more standard post-harvest practice of simply chopping rice straw prior to fall flood-up. Finally, aqueous methylmercury (MeHg) concentrations and export were highly variable, and seasonal trends in particular were often opposite to those of caged fish. Aqueous MeHg concentrations and loads were substantially higher in winter than in summer, whereas caged fish Hg concentrations were relatively low in winter and substantially higher in summer. Together, our results highlight the importance of habitat, seasonal processes, and wetland management practices on Hg cycling and ecological risk in aquatic ecosystems.

  10. Adaptation to flooding during emergence and seedling growth in rice and weeds, and implications for crop establishment

    PubMed Central

    Ismail, Abdelbagi M.; Johnson, David E.; Ella, Evangelina S.; Vergara, Georgina V.; Baltazar, Aurora M.

    2012-01-01

    Background and aims Direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. However, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. Conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herbicides; however, numerous weed species are adapted to lowlands and present challenges for the use of flooding to control weeds. Advancing knowledge on the mechanisms of tolerance of flooding during germination and early growth in rice and weeds could facilitate the development of improved rice varieties and effective weed management practices for direct-seeded rice. Principal results Rice genotypes with a greater ability to germinate and establish in flooded soils were identified, providing opportunities to develop varieties suitable for direct seeding in flooded soils. Tolerance of flooding in these genotypes was mostly attributed to traits associated with better ability to mobilize stored carbohydrates and anaerobic metabolism. Limited studies were undertaken in weeds associated with lowland rice systems. Remaining studies compared rice and weeds and related weed species such as Echinochloa crus-galli and E. colona or compared ecotypes of the same species of Cyperus rotundus adapted to either aerobic or flooded soils. Conclusions Tolerant weeds and rice genotypes mostly developed similar adaptive traits that allow them to establish in flooded fields, including the ability to germinate and elongate faster under hypoxia, mobilize stored starch reserves and generate energy through fermentation pathways. Remarkably, some weeds developed additional traits such as larger storage tubers that enlarge further in deeper flooded soils (C. rotundus). Unravelling the mechanisms involved in adaptation to flooding will help design management options that will allow tolerant rice genotypes to adequately establish in flooded soils while simultaneously suppressing weeds. PMID:22957137

  11. Molecular evidence on the origin and evolution of glutinous rice.

    PubMed Central

    Olsen, Kenneth M; Purugganan, Michael D

    2002-01-01

    Glutinous rice is a major type of cultivated rice with long-standing cultural importance in Asia. A mutation in an intron 1 splice donor site of the Waxy gene is responsible for the change in endosperm starch leading to the glutinous phenotype. Here we examine an allele genealogy of the Waxy locus to trace the evolutionary and geographical origins of this phenotype. On the basis of 105 glutinous and nonglutinous landraces from across Asia, we find evidence that the splice donor mutation has a single evolutionary origin and that it probably arose in Southeast Asia. Nucleotide diversity measures indicate that the origin of glutinous rice is associated with reduced genetic variation characteristic of selection at the Waxy locus; comparison with an unlinked locus, RGRC2, confirms that this pattern is specific to Waxy. In addition, we find that many nonglutinous varieties in Northeast Asia also carry the splice donor site mutation, suggesting that partial suppression of this mutation may have played an important role in the development of Northeast Asian nonglutinous rice. This study demonstrates the utility of phylogeographic approaches for understanding trait diversification in crops, and it contributes to growing evidence on the importance of modifier loci in the evolution of domestication traits. PMID:12399401

  12. Genetic diversity for mycorrhizal symbiosis and phosphate transporters in rice.

    PubMed

    Jeong, Kwanho; Mattes, Nicolas; Catausan, Sheryl; Chin, Joong Hyoun; Paszkowski, Uta; Heuer, Sigrid

    2015-11-01

    Phosphorus (P) is a major plant nutrient and developing crops with higher P-use efficiency is an important breeding goal. In this context we have conducted a comparative study of irrigated and rainfed rice varieties to assess genotypic differences in colonization with arbuscular mycorrhizal (AM) fungi and expression of different P transporter genes. Plants were grown in three different soil samples from a rice farm in the Philippines. The data show that AM symbiosis in all varieties was established after 4 weeks of growth under aerobic conditions and that, in soil derived from a rice paddy, natural AM populations recovered within 6 weeks. The analysis of AM marker genes (AM1, AM3, AM14) and P transporter genes for the direct Pi uptake (PT2, PT6) and AM-mediated pathway (PT11, PT13) were largely in agreement with the observed root AM colonization providing a useful tool for diversity studies. Interestingly, delayed AM colonization was observed in the aus-type rice varieties which might be due to their different root structure and might confer an advantage for weed competition in the field. The data further showed that P-starvation induced root growth and expression of the high-affinity P transporter PT6 was highest in the irrigated variety IR66 which also maintained grain yield under P-deficient field conditions. PMID:26466747

  13. TOND1 confers tolerance to nitrogen deficiency in rice.

    PubMed

    Zhang, Yangjun; Tan, Lubin; Zhu, Zuofeng; Yuan, Lixing; Xie, Daoxin; Sun, Chuanqing

    2015-02-01

    Nitrogen (N), the most important mineral nutrient for plants, is critical to agricultural production systems. N deficiency severely affects rice growth and decreases rice yields. However, excessive use of N fertilizer has caused severe pollution to agricultural and ecological environments. The necessity of breeding of crops that require lower input of N fertilizer has been recognized. Here we identified a major quantitative trait locus on chromosome 12, Tolerance Of Nitrogen Deficiency 1 (TOND1), that confers tolerance to N deficiency in the indica cultivar Teqing. Sequence verification of 75 indica and 75 japonica cultivars from 18 countries and regions demonstrated that only 27.3% of cultivars (41 indica cultivars) contain TOND1, whereas 72.7% of cultivars, including the remaining 34 indica cultivars and all 75 japonica cultivars, do not harbor the TOND1 allele. Over-expression of TOND1 increased the tolerance to N deficiency in the TOND1-deficient rice cultivars. The identification of TOND1 provides a molecular basis for breeding rice varieties with improved grain yield despite decreased input of N fertilizers. PMID:25439309

  14. TOND1 confers tolerance to nitrogen deficiency in rice

    PubMed Central

    Zhang, Yangjun; Tan, Lubin; Zhu, Zuofeng; Yuan, Lixing; Xie, Daoxin; Sun, Chuanqing

    2015-01-01

    Nitrogen (N), the most important mineral nutrient for plants, is critical to agricultural production systems. N deficiency severely affects rice growth and decreases rice yields. However, excessive use of N fertilizer has caused severe pollution to agricultural and ecological environments. The necessity of breeding of crops that require lower input of N fertilizer has been recognized. Here we identified a major quantitative trait locus on chromosome 12, Tolerance Of Nitrogen Deficiency 1 (TOND1), that confers tolerance to N deficiency in the indica cultivar Teqing. Sequence verification of 75 indica and 75 japonica cultivars from 18 countries and regions demonstrated that only 27.3% of cultivars (41 indica cultivars) contain TOND1, whereas 72.7% of cultivars, including the remaining 34 indica cultivars and all 75 japonica cultivars, do not harbor the TOND1 allele. Over-expression of TOND1 increased the tolerance to N deficiency in the TOND1-deficient rice cultivars. The identification of TOND1 provides a molecular basis for breeding rice varieties with improved grain yield despite decreased input of N fertilizers. PMID:25439309

  15. Identification and quantification of anthocyanin pigments in colored rice.

    PubMed

    Kim, Min-Kyoung; Kim, Han-Ah; Koh, Kwangoh; Kim, Hee-Seon; Lee, Young Sang; Kim, Yong Ho

    2008-01-01

    Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with lambda(max) of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G. PMID:20126365

  16. 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

  17. A Stable Urban Ecosystem

    ERIC Educational Resources Information Center

    Meier, Richard L.

    1976-01-01

    Describes a model for the future evolution of a stable ecosystem in a densely-populated society. Discusses designs for limiting population growth, resource-conserving settlements, and ways to feed growing cities. (MLH)

  18. PERSISTENCE IN MODEL ECOSYSTEMS

    EPA Science Inventory

    Mathematical models aid in understanding environmental systems and in developing testable hypotheses relevant to the fate and ecological effects of toxic substances in such systems. Within the framework of microcosm or laboratory ecosystem modeling, some differential equation mod...

  19. Stability of Heterogeneous Ecosystem

    NASA Astrophysics Data System (ADS)

    Liu, Yang-Yu; Yan, Gang; Barabasi, Alber-Laszlo

    2014-03-01

    Stability of ecosystem measures the tendency of a community to return to equilibrium after environmental perturbation, which is severely constrained by the underlying network structure. Despite significant advances in uncovering the relationship between stability and network structure, little attention has been paid to the impact of the degree heterogeneity that exists in real ecosystems. Here we show that for networks with mixed interactions of competition and mutualism the degree heterogeneity always destabilizes the ecosystem. Surprisingly, for predator-prey interactions (e.g., food webs) high heterogeneity is destabilizing yet moderate heterogeneity is stabilizing. These findings deepen our understanding of the stability of real ecosystems and may also have implications in studying the stability of more general complex dynamical systems.

  20. List identifies threatened ecosystems

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-09-01

    The International Union for Conservation of Nature (IUCN) announced on 9 September that it will develop a new Red List of Ecosystems that will identify which ecosystems are vulnerable or endangered. The list, which is modeled on the group's Red List of Threatened Species™, could help to guide conservation activities and influence policy processes such as the Convention on Biological Diversity, according to the group. “We will assess the status of marine, terrestrial, freshwater, and subterranean ecosystems at local, regional, and global levels,” stated Jon Paul Rodriguez, leader of IUCN's Ecosystems Red List Thematic Group. “The assessment can then form the basis for concerted implementation action so that we can manage them sustainably if their risk of collapse is low or restore them if they are threatened and then monitor their recovery.”