We classify modern hybrid rice varieties into three groups, representing different hybrid breeding systems. Insights into the genomic architecture of heterosis for grain yield in rice are presented, and further. Lyp9 displayed heterosis in plant height and grain number per panicle under the natural and shortday length conditions, which would huang zhiyuan, et al. Heterosis expression of hybrid rice in natural and short. Hybrid vigor or heterosis is defined as a superior performance of hybrids, for many traits, relative to their parental inbred lines see chapter 8 of this book. While cumulative small advantages over twolocus combinations. Difficult in breeding intersubspecific hybrid rice low seed set tall plant height poor grainfilling late maturity grain quality market solution for breeding of intersubspecific hybrid rice wide compatibility wc genes allelic dwarf gene indicajavanica hybrids in indica rice growing region japonicajavanica hybrids in japonica rice growing. Production and heterosis analysis of rice autotetraploid.
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. Although the modes of gene expression vary from different studies, the global trends are similar. Furthermore, the development of our knowledge of the oenotheru biology is an outstanding example of how science works and could be of great instructional value for. In selfpollinated crops, utilization of hybrid vigour is dependent upon a system for economically producing f 1 seeds. This work resulted in the production of the first brazilian maize double hybrid in 1939 by krug and coworkers. Heterosis definition types of heterosis heterosis in. Heterosis is a major yield factor in all breeding categories except line breeding schnell, 1982. 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, 2000.
Click download or read online button to get manual for hybrid rice seed production book now. Heterosis and hybrid rice breeding, plant science 10. Ppt heterosis powerpoint presentation free to view. Here, by genome analysis, we found that breeders introduced different introgressed exogenous genomes of other rice subpopulations to construct male and female parents. We developed an innovative hybrid rice breeding strategy that uses the monogenic. Heterosis in rice has revolutionized its breeding and production. Hybrid rice yields about 20 more than the best commercial varieties. Breeding highyield superior quality hybrid super rice by.
Divergent selection and genetic introgression shape the. Comparative transcriptional profiling and preliminary study. 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. Heterosis expression of hybrid rice in different day length conditions 83 help to reveal the mechanisms underlying. Plant and animal breeders exploit heterosis by mating two different purebred lines that have certain desirable traits.
Metabolomebased prediction of yield heterosis contributes. Physiological bases of heterosis and crop management strategies for. Heterosis, or hybrid vigor, refers to the phenomenon that the hybrid of two inbred lines shows superior performance than either parents and is a widely documented phenomenon in diploid organisms that undergo sexual reproduction. Furthermore, the development of our knowledge of the oenotheru biology is an outstanding example of how science works and could be of great instructional value for giving students an understanding of science and to.
Elite hybrid rice, such as the wild abortive and honglian series luo et al, 20. Importance of epistasis as the genetic basis of heterosis in. Genomic analysis of hybrid rice varieties reveals numerous. The spikelet fertility is an important trait affecting the yield in hybrid rice breeding for which more than 50 percent of the hybrids showed significant standard heterosis. Salicylic acid, senescence, and heterosis plant physiology. The genetic basis of heterosis in highly heterotic hybrids has been. The tremendous impact of heterosis in rice breeding in china has. Jul 30, 2017 heterosis is a term used in genetics and breeding and is also known as hybrid vigor. Hybrid rice breeding manual books international rice research.
In rice, altered regulation of gibberellic acid and abscisic acid biosynthesis genes can lead to hybrid vigor chen et al. These results inform on the genomic architecture of heterosis and rice hybrid breeding. Presence of exploitable heterosis and sound seed production techniques are the prerequisites for success of hybrid rice breeding programme while these. Genomic architecture of heterosis for yield traits in rice. Heterosis or hybrid vigor results in a hybrids phenotypic superiority over its founder parents for quantitative and qualitative traits.
Provided here is a concise account of hybrid breeding in rice, a newly deployed. Nucleus and breeder seed production of a, b, r, and tgms lines. Heterosis is a multigenic complex trait and can be extrapolated as the sum total of many physiological and phenotypic traits. The genetic basis of heterosis in highly heterotic hybrids has been studied, but. In an attempt to investigate as many rice hybrid combinations as possible, we sampled a total of 1,495 diverse varieties of hybrid rice.
Production and heterosis analysis of rice autotetraploid hybrids. Dominance is the major genetic basis of heterosis in rice as revealed by qtl analysis using molecular markers jinhua xiao, jiming longping yuant and steven d. In any breeding program, genetic diversity of the germplasm affects the potential genetic gain achievable through selection. Thus, the present research is focused on the grain number heterosis of a widely used latecropping indica super hybrid rice combination in china using a highthroughput. Despite the great contributions of utilizing heterosis to crop productivity worldwide, the molecular mechanism of heterosis remains largely unexplored. Heterosis is an additional gain above the average genetic level of the two parent breeds. The yield potential of a new combination is unknown before field hybridization and phenotyping, which are. The use of heterosis has been intensively explored. Heterosis expression of hybrid rice in natural and shortday. Area devoted to hybrid rice is growing rapidly in each of these countries.
Heterosis and hybrid rice breeding sant singh virmani. Wide compatibility and utilization of intersubspecific heterosis. Heterosis and inheritance of fertilityrestorer genes in rice. The chasm of unanswered questions regarding heterosis is undoubtedly why it still dominates the thinking of many scientists and was the impetus for the manu scripts published in this volume. Heterosis or hybrid vigor, on the other hand, is the tendency of outbred strains to exceed both inbred parents in fitness. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of. However, the exploitation of the male sterility gene from o. For example, heterosis is a genomewide phenomenon involves global table 1. The latter was estimated in comparison to commercial varieties. Heterosis breeding is here to stay as a potent genetic tool for exploiting the predominantly nonadditive gene action. Abstract heterosis and heterotic patterns are important factors exploited to the most. Hybrid vigour in cowpea, as in other crops, is dependent on the specific parents used. Heterosis is the base of the great success in hybrid rice.
China has been successful in breeding hybrid rice strains, but is now facing challenges to develop new hybrids with highyielding potential. Metabolomebased prediction of yield heterosis contributes to. Feb 27, 2017 rice is one of the most important staple foods. Heterosis and hybrid rice breeding heterosis and hybrid rice breeding khush, gurdev s. Genetic analysis for the grain number heterosis of. Organization of hybrid rice breeding program using cms system.
Based on these materials, and the experience of hybrid rice scientists from china and irri, this training manual on the twoline hybrid breeding method has been prepared, which expands upon the hybrid rice breeding manual published earlier by irri. The third experiment estimated the inheritance of fertilityrestorer genes in rice including two f 2 populations, with crosses between ch1 and ch4 new plant type as restorer lines and ir80151a wacms as female parental line. Heterosis breeding, which exploits the phenomenon of hybrid vigor, has proven to be a practical method of crop improvement. Pdf progress in research and development on hybrid rice. This site is like a library, use search box in the widget to get ebook that you want. Heterosis, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents. In brazil, the first research with hybrid maize began in 1933 at the instituto agronomico in campinas, sp. Genomic architecture and heterozygosity of rice hybrids. Heterosis can be defend as the superiority of f hybrid over both the parents in terms of yield and some other character or.
Comparative transcriptional profiling and preliminary. Huang et al, 2015, are perfect combinations of sterile and restorer lines for generating yield heterosis through successful breeding chen et al, 2014. A free powerpoint ppt presentation displayed as a flash slide show on id. Wellin abstract yield testing fi nished inbreds to replace preliminary singlecross corn zea mays l. The three line hybrid corh2 was taken as the standard check to estimate standard heterosis. Although heterosis and hybrid vigor are often used synonymously, hetero. The bonus from heterosis should be approximately 5% for production and 10% for mortality, fertility, health and survival.
Importance of epistasis as the genetic basis of heterosis. The estimation of heterosis in hybrid rice is the greatest practical achievements for hybrid rice im. The hybrid ts29 x ponni recorded the maximum standard. Genetic analysis for the grain number heterosis of a. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials. Heterosis expression of hybrid rice in different day length conditions 83 help to reveal the mechanisms underlying day length regulation of the rice heterosis. We conclude that indepth unlocking of genetic variations among oryza species will further enhance rice breeding. Hybrid rice exploits the phenomenon of hetrosis which can increase the yield potential over hyvs.
Pdf twoline hybrid rice breeding manual researchgate. Is the major genetic basis of heterosis in rice as revealed. Manual for hybrid rice seed production download ebook. Integrated genomic approaches have efficiently investigated many heterotic loci in hybrid rice underlying yield heterosis advantages and revealed the genomic architecture of rice heterosis. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of plant breeding. Maize zea mays and rice oryza sativa are two key crops for which heterosis has increased yields. Both cost and time wise, the most expensive phase in a hybrid breeding program would be the. Tanksley department of plant breeding and biomett, cornell university, zthaca, new york, 14853 and thunan hybrid rice. Mar 03, 2020 the application of heterosis hybrid vigor in hybrid rice since the 1970s has tremendously improved rice productivity worldwide. The application of heterosis hybrid vigor in hybrid rice since the 1970s has tremendously improved rice productivity worldwide. Hybrid rice cultivation area is steadily expanding around the world, especially in southern asia. Full text views reflects the number of pdf downloads, pdfs. In the early stage of the hybrid rice breeding program, breeders identified restorer.
Manual for hybrid rice seed production download ebook pdf. In this article we will discuss about heterosis or hybrid vigour. 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. Pdf for practical exploitation of hybrid vigor in rice, emasculation is a major constraint. This might be the reason why most of the available rice hybrids do not possess better grain quality and disease resistance than the inbred lines. Heterosis or hybrid vigor results in a hybrid s phenotypic superiority over its founder parents for quantitative and qualitative traits. Rice is the staple food for a large segment of the world population. Heterosis and inheritance of fertilityrestorer genes in rice jakkrit seesang, prapa sripichitt, tanee sreewongchai. If you believe the dominance hypothesis, is this the best investment of plant breeding effort. To systematically exploit heterosis in hybrid breeding. 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. The converse or complement to inbreeding depression in which the value d a inbreeding can result in loss of vigor, size, etc. Pdf china has been successful in breeding hybrid rice strains, but is.
Rice is predominantly a selffertilizing plant, so heterosis is not achieved naturally. Current status and future prospects for breeding hybrid rice and wheat. Hybrid vigor is defined by mechanisms such as dominant. Genomic landscapes of heterosis in hybrid rice population. Rice is the most important food crop of the developing world and the demand for it is growing.
Progress in research and development on hybrid rice. 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. Heterotic grouping and its importance in tropical hybrid rice breeding srijan ambati thakur virender jeet singh department of genetics and plant breeding, college of agriculture, professor jayashankar telangana state agricultural university, hyderabad. The exploitation of hybrid vigour in rice has been focusing on increasing grain yield. But how breeders construct hybrid parents to obtain hybrid rice heterosis remains unclear. Is the major genetic basis of heterosis in rice as. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of genetically unlike constituents are crossed together, the resulting hybrids obtained from. Hybrids have been widely used in crop and tree breeding since ancient times, although the molecular mechanisms underlying. The genomics of oryza species provides insights into rice. Research on heterosis, male sterility systems, outcrossing mechanisms. Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding approach to increase the yield. Hybrid rice has proven to be an effective way to enhance rice.