Heterosis expression of hybrid rice in natural and shortday length conditions huang zhiyuan, zhao bingran, lv qiming, fu xiqin, xin yeyun, yuan longping state key laboratory of hybrid rice, hunan hybrid rice research center, changsha 410125, china abstract. If true, it should not be possible to obtain an inbred that performs equally as well as the best hybrid bernardo 2002 breeding for quantitative traits in plants pp 243246. Metabolomebased prediction of yield heterosis contributes to. Manual for hybrid rice seed production download ebook pdf.
In rice, altered regulation of gibberellic acid and abscisic acid biosynthesis genes can lead to hybrid vigor chen et al. Brief history of hybrid rice 1926 heterosis in rice reported 1964 china started hybrid rice research 1970 china discovered a commercially usable genetic tool for hybrid rice male sterility in a wild rice wide abortive 1973 ptgms rice was found in china 1974 first commercial threeline rice hybrid released in china. Male sterility in rice and its potential use in breeding. Genomic analysis of hybrid rice varieties reveals numerous superior alleles that contribute to heterosis. Hybrid rice yields about 20 more than the best commercial varieties. Suji abstract an experiment was undertaken to identify heterotic rice hybrids for aerobic condition based on physiological and root.
Production and heterosis analysis of rice autotetraploid. Organization of hybrid rice breeding program using cms system. In selfpollinated crops, utilization of hybrid vigour is dependent upon a system for economically producing f 1 seeds. The genomics of oryza species provides insights into rice. Hybrid rice exploits the phenomenon of hetrosis which can increase the yield potential over hyvs. Consequently, the best check varieties can be used to estimate the heterosis of hybrid rice.
All discussion papers can be downloaded free of charge. Nucleus and breeder seed production of a, b, r, and tgms lines. Heterosis of japonicajavanica hybrids could be used to increase japonica hybrid yields. Heterosis expression of hybrid rice in natural and shortday. Research article heterosis under aerobic condition in. Hybrid breeding methods are used in maize, sorghum, rice, sugar beet, onion, spinach, sunflowers, broccoli and to create a more psychoactive cannabis. Their grain quality retains japonica characteristics. Genetic analysis for the grain number heterosis of. Increasing yield potential in rice by exploitation of. Pdf for practical exploitation of hybrid vigor in rice, emasculation is a. Heterosis breeding and inbreeding depression authorstream. Breeding highyield superior quality hybrid super rice by.
Heterosis and inheritance of fertilityrestorer genes in rice. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials. Breeding hybrid rice between indica and japonica would be dramatically enhanced if such fertility heterosis exists and could be incorporated into breeding programs for hybrid rice. Country hybrid rice area 1,000 ha hybrid rice area 1,000 ha hybrid rice area 1,000 ha hybrid rice area 1,000 ha hybrid rice area 1,000 ha country 1997 2001 2004 2005 2006 bangladesh 15 50 90 150 exp india 100 200 560 na. Sep 29, 2016 heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. Tawari et al19 reported that more than 60% of standard heterosis compared with the best of check varieties has high speci. The genetic basis of heterosis in highly heterotic hybrids has been studied, but. Balance between a higher degree of heterosis and increased. Presence of exploitable heterosis and sound seed production techniques are the prerequisites for success of hybrid rice breeding programme while these. Heterosis expression of hybrid rice in natural and short. Elite hybrid rice, such as the wild abortive and honglian series luo et al, 20. Exploring the molecular basis of heterosis for plant breeding.
Heterosis and hybrid rice breeding sant singh virmani. Commercial hybrid rice yield and hybrid rice seed yield in china 19762008. Dominance, overdominance and epistasis condition the. The success of hybrid rice breeding, together with saturated molecular linkage maps 14, 15 and relatively small genome size of this species, has provided a rare opportunity for dissecting the genetic basis of heterosis in elite rice hybrids.
Phase hybrid rice yield increase% early season late season single season 1996 level 7. Most of super rice breeding programs in china have used intersubspecies heterosis cheng et al. Rice is the staple food for a large segment of the world population. Besides applications of heterosis in grain crops, hybrid breeding is also one of the great choices in many other plants including rapeseed, sun. Key message genetic basis of grain yield heterosis relies on the cumulative effects of dominance, overdominance, and epistasis in maize hybrid yuyu22. Rice is the most important food crop of the developing world and the demand for it is growing. Research on heterosis, male sterility systems, outcrossing mechanisms. The application of heterosis hybrid vigor in hybrid rice since the 1970s has tremendously improved rice productivity worldwide. Concepts and breeding of heterosis in crop plants, the third joint plant breeding symposia, was held on sunday, 3. Heterosis, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. Advances in hybrid rice technology, proceedings of the 3rd international symposium on hybrid rice 1416 november 1996 hyderabad india. Average heterosis fl mpmp x 100 where, f, is the mean value of7, and mp is the mean value of two parents involved in the cross. Progress in research and development on hybrid rice oxford.
Hybrid breeding has been an important method of increasing grain yield of rice and intersubspecific crosses, such as indica and japonica, showed a great potential to raise grain yield than other crosses yuan 1987. Grain yield manifested highly significant heterosis, heterobeltiosis. Huang et al, 2015, are perfect combinations of sterile and restorer lines for generating yield heterosis through successful breeding chen et al, 2014. To examine the genetic basis of heterosis for yield in rice, here we generate, sequence and record the phenotypes of 10,074 f2 lines from 17 representative hybrid rice. Heterosis and hybrid seed production in agronomic crops discusses how heterosis or hybrid vigor has played a major role in improving crop productivity and quality in order to feed the everincreasing human population. In my opinion, hybrid corn is the most far reaching development in applied biology in this quarter century mangelsdorf, 1951. Feb 27, 2017 rice is one of the most important staple foods. Rice, super hybrid rice, heterosis, grain number, rnaseq background heterosis is a phenomenon in which hybrids exhibit superiority over their parental lines in economic traits, such as enhanced biomass production, development rate, stress tolerance and, most important, grain yield. Genomic architecture of heterosis for yield traits in rice. Heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. However, the exploitation of the male sterility gene from o.
We collected and sequenced 1,495 diverse varieties of hybrid rice. The latter was estimated in comparison to commercial varieties. We developed an innovative hybrid rice breeding strategy that uses the monogenic recessive. Heterosis breeding is here to stay as a potent genetic tool for exploiting the predominantly nonadditive gene action. Rice is predominantly a selffertilizing plant, so heterosis is not achieved naturally. Sep 25, 2012 heterosis refers to the superior performance of hybrids relative to the parents. Heterosis is used to increase yields, uniformity, and vigor.
Breeding, china national hybrid rice research and development center, changsha 410125, china manuscript received may 26, 2008 accepted for publication september 10, 2008. Here, by genome analysis, we found that breeders introduced different introgressed exogenous genomes of other rice subpopulations to construct male and female. Plant and animal breeders exploit heterosis by mating two different purebred lines that have certain desirable traits. After maize hybrid was first utilized in field on a large scale in usa in 1930s, heterosis of other crops such as rice, sorghum, rape, and vegetable etc began to be widely used in production, and had made great achievements in crop breeding by the end of last century, mainly contributed to notable increasing of crop yield. Hybrid rice is now a viable commercial product in countries such as china and india that rely on this plant as their major food cereal. Corn maize nearly all field corn grown in most developed nations exhibits heterosis.
Divergent selection and genetic introgression shape the. In this article we will discuss about heterosis or hybrid vigour. Pdf on jan 1, 2003, s s virmani and others published twoline hybrid rice breeding. The bonus from heterosis should be approximately 5% for production and 10% for mortality, fertility, health and survival. Plant breeders often cross different types of rice to produce hybrids with increased yields and other advantageous traits. However, the understanding of the underpinning biological mechanism is still fragmentary after a century of debate and quest. The phenomenon heterosis has been applied to rice breeding for improving grain yield since the early 1970s in china cheng et al. Breakthrough for hybrid rice breeding, in fact, was made in china during 1976. Analysis of the relationship between coefficients of. Heterosis is a phenomenon in which hybrids exhibit superior performance relative to parental. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of genetically unlike constituents are crossed together, the resulting hybrids obtained from. Ppt heterosis powerpoint presentation free to download.
Ppt hybrid rice breeding powerpoint presentation free. When the heterosis is estimated over the mid parent, i. Selective breeding of plants and animals, including hybridization, began long before there was an understanding of underlying scientific principles. Heterosis, also called hybrid vigour, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. Increasing grain yield is a longterm goal in crop breeding to meet the demand for global food security.
Furthermore, many new germplasms or intermediate lines have been widely used in hybrid rice breeding in recent years to achieve superior rice quality, blast resistance and lengthen storage time. Is the major genetic basis of heterosis in rice as. Heterosis breeding is the one of the strongest tool for breeder to complete targated demand of 2030 as rice is self pollinated species male sterility is essential for hybrid rice production. Although there have been a range of studies on various aspects of heterosis, the key to understanding the biological mechanisms of heterotic performance in crop hybrids is the genetic basis, much of which. Pdf twoline hybrid rice breeding manual researchgate. The best twoline system indicaindica hybrids can outyield cms indicaindica hybrids by 510 percent. If you believe the dominance hypothesis, is this the best investment of plant breeding effort. Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding approach to increase the yield. Studies conducted at the international rice research institute irri during 1980 and 1981 have shown up to 73% heterosis, 59% heterobeltiosis and 34% standard heterosis for yield in rice. Heterosis is an additional gain above the average genetic level of the two parent breeds. Aug 29, 2017 the phenomenon heterosis has been applied to rice breeding for improving grain yield since the early 1970s in china cheng et al. Later, a series of indica hybrids such as nanyou 2 and shanyou 63 were. In recent years, unlocking the genetic diversity of species has provided insights into the genomics of rice domestication, heterosis, and complex traits. Current status and future prospects for breeding hybrid rice and wheat.
However, the heterosis related genes associated with rice grain production remain largely unknown. Determination of heterotic groups and heterosis analysis. Physiological bases of heterosis and crop management strategies for. Heterosis in rice has revolutionized its breeding and production.
Now a large research project coled by the chinese academy of agricultural sciences has dissected the genetic architecture underpinning this hybrid success. Transcriptome analysis of rice root heterosis by rnaseq. To examine the genetic basis of heterosis for yield in rice, here we generate, sequence and record the phenotypes of 10,074 f2 lines from 17 representative hybrid rice crosses. Importance of epistasis as the genetic basis of heterosis. The analyses displayed a picture that accumulation of small advantages genomewide could explain the genetic basis of heterosis in this elite rice hybrid. Dominance, overdominance and epistasis condition the heterosis in two heterotic rice hybrids. To breed an ideal cross with the highest grain yield and great stress resistance is the ultimate goal of hybrid rice breeders. From 1976, during which hybrid seeds were first released to rice farmers, to 1991 during which the planted acreage of hybrid rice accounted for 55% of total planted area of paddy rice in. But how breeders construct hybrid parents to obtain hybrid rice heterosis remains unclear.
Hybrid rice breeding for exploiting hybrid vigor, heterosis, has greatly increased grain yield. The application of heterosis hybrid vigor has brought great success to plant breeding, particularly of hybrid rice, achieving significant yield. Genetics biotechnology and breeding of maize and sorghum. Jul 30, 2017 heterosis is a term used in genetics and breeding and is also known as hybrid vigor. Sep 25, 2012 heterosis, or hybrid vigor, refers to the superior performance of the hybrids relative to the parents. Salicylic acid, senescence, and heterosis plant physiology. Wide compatibility and utilization of intersubspecific heterosis. Heterosis definition types of heterosis heterosis in.
Analysis on genetic diversification and heterosis in. Genetic composition of yield heterosis in an elite rice hybrid. The firstgeneration offspring generally show, in greater measure, the desired characteristics of both parents. Manual for hybrid rice seed production download ebook. Heterosis or hybrid vigor, on the other hand, is the tendency of outbred strains to exceed both inbred parents in fitness. Genomic analysis of hybrid rice varieties reveals numerous. Ppt heterosis powerpoint presentation free to view id.
Ploid manipulation might achieve even greater heterosis from crosses between the indica and japonica rice subspecies and result in a larger rice plant li and xu. Heterosis or hybrid vigour is a phenomenon in which hybrid progeny exhibit superior yield and biomass to parental lines and has been used to breed f1 hybrid cultivars. We classify modern hybrid rice varieties into three groups, representing different hybrid breeding systems. Genome sequencing and analysis of numerous wild rice and asian cultivated rice accessions have enabled the identification of genomewide signatures of. A plant breeding phenomena that we very successful exploit commercially, the biological basis of which remains poorly understood.
Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding. Development of hybrid rice is an important strategy to increase yields of. Utilization of heterosis has tremendously increased productivity of many crops globally. Heterosis, when a hybrid shows higher performance for a trait than both parents, offers an. The term heterosis, often used synonymously with hybrid vigor, refers to the superiority of the f 1 hybrid over its parents. Ppt heterosis powerpoint presentation free to view. Production and heterosis analysis of rice autotetraploid hybrids. Utilization of heterosis has contributed tremendously to the increased productivity in many crops for decades. Heterosis expression of hybrid rice in natural and shortday length conditions. Heterosis is the foundation of the great success of hybrid rice in china. The yield potential of a new combination is unknown before field hybridization and phenotyping, which are. Hybrid vigour in cowpea, as in other crops, is dependent on the specific parents used. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of plant breeding. Practice and thought on developing hybrid rice for super.
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