An example from thailand boonrat jongdeea, grienggrai pantuwanb, shu fukaic, ken fischerc a ubon ratchathani rice research center, ubon ratchathani 34000, thailand b rice research institute, bangkok, thailand c school of land and food sciences, the university of queensland, brisbane, qld 4072, australia. Improving drought tolerance in rainfed lowland rice. Drought tolerance indices under normal and water stress condition. Yly6 is a twoline hybrid rice variety with characteristics of high yield and high quality and higher drought tolerance and bred by lixiahe regional. Quantitative trait loci qtls for drought tolerance dt can be readily identified in available databases and in this paper, these qtls were summarized in the form of a consensus map. Germplasm innovation of heat tolerance in rice for. Worldwide, approximately 27 million ha of rice are grown in upland rather than paddy fields, and is subject to drought stress. Second africa rice congress, bamako, mali, 2226 march 2010.
Towards improving the drought tolerance of rice in china volume 4 issue 1 hongyan liu, hanwei mei, xinqiao yu, guihua zou, guolan liu, lijun luo. Induction of salt tolerance in rice oryza sativa l. Identification of drought tolerant rice oryza sativa l. The sub1a protein increases transcription of genes associated with ethanolic fermentation and represses transcription of genes associated with cell elongation and carbohydrate catabolism. In this study, we confirmed that oslg3 was more highly expressed in irat109. Drought is one of the major abiotic stresses that affect rice production in rainfed areas. Although exposure of rice plants to prolonged submergence results in severe leaf senescence, genotypes containing sub1a are able to recover after desubmergence through formation of new leaves fukao et al. Flooding effects on rice rice is the stable food for over half of humanity, 23 of the worlds poor floods annually reduce productivity in over 22 million ha of rice in asia and large area in africa incidences set farmers deeper into debt and poverty floods are worsening with climate change scientific discoveries provided opportunities to. Rice plants generally tolerate salt by mainly two mechanisms, ion exclusion and osmotic tolerance munns and tester, 2008. This article provides a case study on transgenic rice for stress tolerance. Rice bran is used in cattle and poultry feed, defatted bran, which is rich in protein, can be used in the preparation of biscuits and as cattle feed.
Screening rice varieties for tolerance to mineral stresses in soils screening rice for tolerance to mineral stresses save as. Salt tolerance enhancement in indica rice oryza sativa. Towards improving the drought tolerance of rice in china plant. Drought tolerance and aerobic rice breeding at irri international rice research institute learning objectives what is the problem. Growth and production of rice encyclopedia of life. Required for drought tolerance and grain yield under.
Unesco eolss sample chapters soils,plant growth and crop production vol. A major qtl sub1 explaining about 70% of phenotypic variation in submergence tolerance has been identified and mapped on chromosome 9 in the submergence tolerant cultivar. Based on the dry weight of the root, three pbtolerant var ch55, var kh2j, var kumnung and three pbsensitive var aixueru, var c9491, var milyang23 rice. In this study, we functionally characterized the rice drought responsive. Drought is a major challenge limiting rice production. Enhanced tolerance to drought in transgenic rice plants. On the basis of tolerance ability toward salinity, rice is considered as saltsensitive crop, and growth and yield of rice are greatly affected by salinity. The international rice research institute irri was established in 1960 by the ford and rockefeller foundations with the help and. Developing rice cultivars with tolerance of submergence and with agronomic and quality traits acceptable to farmers is a feasible approach to address this problem. Review the current understanding of the biology, genetics and molecular aspects of tolerance in rice.
The impact of these new plant types will depend both on their drought and weedtolerance, and the acceptability and adoption of new plant types by farmers. Physiological mechanisms of iron toxicity tolerance in. Pdf improving drought tolerance in rainfed lowland rice. Calculate the allowable maintenance and acceptance tolerances for legal for trade applications. Mapping qtl for heattolerance at grain filling stage in rice. Drought tolerance is an important quantitative trait with multipart phenotypes that are often further complicated by plant phenology. Droughtprone lowlands severe seasonlong drought destroyed plantings in upper fields at raipur 2002 kdml 105 under severe lateseason stress in upper field at roi et, thailand oct. To facilitate the selection or development of drought tolerant rice varieties, a thorough understanding of the various mechanisms that govern the yield of rice.
Drought resistance in rice from conventional to molecular. This shows the potential impact of breeding for stress tolerance. The irrigation control was performed by tensiometer sets. Rice types and products there are two main types of rice, japonica and indica, differentiated by the area where they are grown and by their traits when cooked. Nam, ataf12, and cuc2 nac transcription factors are known to be associated with various developmental processes and stress tolerance. Plant tolerance of low soil ph, soil aluminum, and soil manganese r. Screening rice for tolerance to mineral stresses 1977. The use of grain yield as a selection criterion at the international rice research. Production of agronomically useful transgenic rice has been given top priority in the improvement of crop plants. Pdf drought resistance is defined as the ability of a plant to produce its maximum economic product under waterdeficit environmental conditions. Development of cold tolerant breeding lines using qtl. Silva2 abstract water deficit is one of the environmental factors that cause a great reduction in the upland rice grain yield. Drought tolerance mechanisms include cellular adjustments, physiological acclimation and morphological adaptations which are controlled by. Acclimation and tolerance strategies of rice under drought stress.
For both formats the functionality available will depend on how you access the ebook via bookshelf online in your browser or via the bookshelf app on your pc or mobile device. Now a trehalose6phosphate t6p phosphatase, ostpp7, is shown to enhance anaerobic germination tolerance by. Genetic architecture of aluminum tolerance in rice oryza sativa determined through genomewide association analysis and qtl mapping adam n. Genetic studies in heat tolerant genotypes for yield, quality and floral traits of rice oryza sativa l. Exploring traditional austype rice for metabolites. These mechanisms can also be further classified into ion exclusion, osmotic tolerance and tissue tolerance roy et al. Agricultural rice production germinates seeds and establishes seedlings underwater. Threedayold seedlings were treated for 12 d with 20. Mechanisms of drought tolerance in rice 19 drought tolerance in rice in an abadependent manner fukao and xiong, 20. Innovation and partnerships to realize africas rice potential 1. Root response to drought stress in rice oryza sativa l. Selecting calibration weights rice lake weighing systems. Tolerance of upland rice genotypes to water deficit cleber m. Genetic and physiological analyses of the tolerance mechanisms to ferrous iron toxicity in rice oryza sativa l.
Dhurve department of plant physiology, jawaharlal nehru krishi vishwa vidyalaya. Panicle water potential, a physiological trait to identify drought. Pdf insilico analysis of drought tolerant genes in rice. Stress and disease tolerance irri rice knowledge bank. Flash floods or shortterm submergence regularly affect around 15 million hectares of rice oryza satival. This indicates that sub1a contributes to protection of meristematic cells from submergence and reoxygenation.
Rice is central to the lives of billions of people around the world. The direct involvement of farmers in the testing and selection of new plant types should. A new method for evaluating the drought tolerance of upland rice. Drought tolerance in upland rice 203 acta scientiarum. Drought is the most severe abiotic stress reducing rice yield in rainfed drought prone ecosystems. Drought yield index to select high yielding rice lines. Effects of salinity stress on growth, chlorophyll content.
The loss of rice yield due to stress impact is estimated to. The dry matter production and the concentration of nutrients in rice oryza sativa l. Identification of drought tolerant rice international journal of. Plants have evolved to have sophisticated adaptation mechanisms to cope with drought stress by reprograming transcriptional networks through drought responsive transcription factors. Class iii tolerance app rice lake weighing systems. Inheritance of cold tolerance in rice at the germination stage. Submergence is a recurring problem in the riceproducing rainfed lowlands of south and southeast asia. Identification of rice varieties with high tolerance or. Breeding for heat tolerance in rice was started in 2010 at the philippine rice research institute, the philippines, when a research proposal titled breeding. Rice tends to be more sensitive to drought stress than other crops.
Refined oil can be used as a cooling medium like cotton seed oil corn oil. Overexpression of jerf1 improves drought tolerance of rice. Improvement of drought tolerance in rice oryza sativa l. Rice bran wax, a byproduct of rice bran oil is used in industries. Currently, recommended strategies to overcome the adverse effects of salt stress include the use of.
Drought remains as one of the major constraints limiting rice productivity. The different influences of drought stress at the flowering stage on. Discuss the challenges in rice breeding for excess water environmen ts. Plant tolerance of low soil ph, soil aluminum, and soil.
Genetic architecture of aluminum tolerance in rice oryza. Drought resistance tolerance has to be researchable, breakable into simpler levels e. Possibly the oldest domesticated grain 10,000 years, rice is the staple food for 2. Enhanced tolerance to drought in transgenic rice plants overexpressing c4 photosynthesis enzymes. T ransgenic rice plants overexpressing osbzip23 showed an increased aba. June, 2016 water deficit, irrigation was applied when the soil water potential reached 0. During the early growth stages of rice, the occurrence of low temperature stress inhibits germination, seedling establishment and eventually leads to non uniform crop maturation. Effects of salinity stress on growth, chlorophyll content and ion accumulation in two indica rice oriza sativa l.
In general, rice can tolerate a small amount of saltwater without compromising the growth and. Pdf rice is one of the most important food crop drastically affected by drought in lowland rice ecosystem. Drought response indices for identification of drought tolerant genotypes in rainfed upland rice oryza sativa l. Overexpression of osnac14 improves drought tolerance in rice. An in silico strategy was then deployed to mine for candidate genes associated with dt qtls using rice dbest and rice genome databases. Excess salinity in soil is one of the major environmental factors that limit plant growth and yield of a wide variety of crops including rice. Genetic and physiological analyses of the tolerance. Oslg3 is associated with drought stress tolerance in rice. Salt tolerance enhancement in indica rice oryza sativa l. Morphological and molecular genetic consideration article pdf available in plant growth regulation 502. Acclimation and tolerance strategies of rice under drought. Yost of soils with low ph has been the subject of a series of scientific symposiums silva 1976, marschner 1991, edwards 1993, maranville et al.
The development of rice cultivars that tolerate high feiia concentrations under a range of environmental conditions is lengthy and has been hindered by the lack of standardized screening methodology. Rice qtls for root growth rate and root penetration ability have also been. Physiology of stress tolerance in rice proceedings of the international conference on stress physiology of rice 28 feb 5 march 1994, lucknow, u. Variation in intensity and severity of drought from season to season and place to place requires cultivation of rice varieties with different level of drought tolerance in different areas.
Rice provides 21% of global human per capita energy and 15% of per capital protein. Hence, water related stress cause severe threat to rice production. To date screening tools for fetoxicity tolerance in rice are based on leaf symptoms and yield, but not on actual resistance mechanisms. A rapid screening technique for salt tolerance in rice. In our previous cdna microarray experiment, osmotic stress caused by 15% wv polyethylene glycol peg induced the expression of oslg3 more strongly in upland rice ur, irat109, and haogelao than in lowland rice lr, nipponbare, and yuefu. Beighley encyclopedia of life support systems eolss 2. Use the resources below to help select the right weight for the right application. Mccouch1 1department of plant breeding and genetics, cornell university, ithaca, new york. Recent trends in climate change have predicted a further increase in drought intensity, making the development of new droughttolerant rice cultivars critical to sustain rice production in this ecosystem. Germination vigor and seedling survival rate are the two main criteria used for the evaluation of cold tolerance in rice at the germination stage. It affects rice at morphological reduced germination, plant height, plant biomass, number of tillers, various root and leaf traits. Fukao and colleagues propose a model in which increased ethylene levels inside submerged plant tissues result in an accumulation of sub1a transcript in submergencetolerant rice.
Assessment of salinity tolerance in rice using seedling. Several authors have pointed out that tolerance of toxic conditions of al or mn in soils of low ph has the components of. Screening of some rice varieties and landraces cultivated. Pdf mechanisms of drought tolerance in rice researchgate. To study pb tolerance in rice oryza sativa, we screened 229 varieties for pb tolerance or sensitivity. Multi environment evaluation of breeding lines helps breeder to identify appropriate. Rice lake weighing systems manufactures a wide selection of quality calibration weights for various applications. In recent years, a specific group of rice, so called austype rice, has been discovered as a valuable source of stress tolerance. Tolerance of upland rice genotypes to water deficit.
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