Feb 27, 2017 rice is one of the most important staple foods. Abstract this research was carried out to assess heritability and heterosis among 30 rice genotypes for yield and related parameters at the university of agriculture peshawarpakistan, during 2011. Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding approach to increase. Ppt heterosis powerpoint presentation free to view. Metabolomebased prediction of yield heterosis contributes. In fact, enhanced heterosis greater than 40% observed at irri in indicatropical japonica crosses encouraged us to develop cms lines in the genetic background of elite tj lines possessing wide compatibility wc genes. The success of future hybrid rice programme depends upon identification of parents having good combining ability with higher magnitude of heterosis and good restorer and maintainer capabilities.
In this perspective, we consider that it might be useful to the field to. Even within the same plant species, the magnitude of heterosis is quite. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials. Genomic architecture of heterosis for yield traits in rice. Genetic analysis of heterosis for yield and yield components. Mar 22, 2014 heterosis or hybrid vigor is a natural phenomenon whereby hybrid offspring of genetically diverse individuals display improved physical and functional characteristics relative to their parents. Exploring the molecular basis of heterosis for plant breeding. Heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. Metabolomebased prediction of yield heterosis contributes to. Insights into the genomic architecture of heterosis for grain yield in rice are presented, and further mapping of grain yield loci resolves candidate genes that could be useful for breeding. To understand the genetic basis of inbreeding depression and heterosis in rice, maineffect and epistatic qtl associated with inbreeding depression and heterosis for grain yield and biomass in five related rice mapping populations were investigated using a complete rflp linkage map of 182 markers, replicated phenotyping experiments, and the mixed model approach. Now a large research project coled by the chinese academy of agricultural sciences has. Transcriptome analysis of neotetraploid rice reveals.
Heterosis for grain yield and its component traits in rice. Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding approach to increase the yield. Heterosisandhybridricejf677932020 adobe acrobat reader. Hierarchical additive effects on heterosis in rice oryza. Heterosis and inheritance of fertilityrestorer genes in rice jakkrit seesang, prapa sripichitt, tanee sreewongchai department of agronomy, faculty of agriculture, kasetsart university, bangkok 10900 thailand corresponding author, email. Here, hochholdinger and baldauf provide an overview of this fascinating biological phenomenon and what is known about the underlying genetics and mechanisms.
Heterosis is a phenomenon in which hybrids exhibit superior performance relative to parental. The agronomic traits of 33 control autotetraploid hybrids and 40 other hybrids generated by crossing with various autotetraploid lines i. Now a large research project coled by the chinese academy of agricultural sciences has dissected the genetic architecture underpinning this hybrid success. 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 offers best genetic solution for improvement of lowly heritable reproductive traits. Co2 exchange rate, dry matter, f1 hybrid, heterosis, leaf area, yield.
Shull 1952 coined the term heterosis and defined it as. The first attempts to find out about underlying mechanisms were based on theoretical models, which were useful, but could not characterize this unique phenomenon as a whole. Assessment and maintenance of genetic purity of varieties and hybrids are crucial for the productivity and quality imparted by breeders. Heterosisandhybridriceih835082020 adobe acrobat reader dcdownload adobe acrobat. Heterosisandhybridricejf677932020 adobe acrobat reader dcdownload adobe acrobat. 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. Heterosis and inheritance of fertilityrestorer genes in rice. Transcriptome analysis of rice root heterosis by rnaseq. Salicylic acid, senescence, and heterosis plant physiology. Jan 10, 2017 heterosis analysis of neotetraploid rice.
Heterosis refers to the phenomenon that progeny of diverse varieties of a species or crosses between species exhibit greater biomass, speed of development, and fertility than both parents. Despite the great contributions of utilizing heterosis to crop productivity worldwide, the molecular mechanism of heterosis remains largely unexplored. Heterosis or hybrid vigor results in a hybrids phenotypic superiority over its founder parents for quantitative and qualitative traits. 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 nextgeneration rnaseq strategy. The extent of heterosis identified in our study is comparable to that from the research by zhang et al. An international symposium on heterosis in crops, 1722 august, 1997, mexico city, mexico. Heterosis or hybrid vigour in the first generation f 1 seeds, obtained by crossing genetically distant breeding lines, is well known in crop breeding shull, 1952.
Dominance is the major genetic basis of heterosis in rice as. Hybrid vigor is defined by mechanisms such as dominant. The remaining 10 27% qtls were detected in both bc1f7 populations, and the heterozygote had a phenotype falling between those of the two homozygotes and in no instances were the heterozygotes found to be superior to both homozygotes. Rnaseq technology was used to analyze the transcriptome of two rice hybrids, ajay based on wildabortive wacytoplasm and rajalaxmi based on kalingacytoplasm, and their respective parents at the panicle initiation pi and grain filling gf stages. Pdf heterosis for yield and yield components in rice. Eight genotypes consisting three basmati varieties viz, basmati kasturi, basmati 370 and basmati with five manipur scented rice landraces viz, chakhao poireiton, chakhao, chakhao amubi, ching chakhao and chakhao angangba were crossed in 8x8 diallel fashion without recieprocal producing twenty eight f 1 hybrids and were evaluated to estimate mid parent heterosis for eleven yield contibuting. Sep 29, 2016 heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. Ppt heterosis powerpoint presentation free to view id.
This site is like a library, use search box in the widget to get ebook that you want. Genotypic correlations, heterosis, inbreeding depression and transgressive segregation of agronomic traits in a diallel cross of rice oryza sativa l. Physiomorphological studies of f1 hybrids in rice oryza sativa l. Hybrid rice technology exploits the phenomenon of hybrid vigor heterosis to increase the yield potential of rice varieties with reported yield advantage of 1520% over inbred commercial highyielding varieties hyvs. Aug 01, 2001 to understand the genetic basis of inbreeding depression and heterosis in rice, maineffect and epistatic qtl associated with inbreeding depression and heterosis for grain yield and biomass in five related rice mapping populations were investigated using a complete rflp linkage map of 182 markers, replicated phenotyping experiments, and the mixed model approach. Sep 24, 2018 heterosis, also known as hybrid vigor, is a wellknown phenomenon whereby hybrid offspring resulting from cross pollination exhibit greater vigor than either parent. Heterosis, or hybrid vigor, has contributed substantially to genetic improvements in crops and trees and its physiological basis involves multiple processes. Defined and research experience cows that are lowcost, adaptable to feed and environmental resources. Genetic analyses of f1 hybrids in maize, rice, and canola have defined a large number of quantitative trait loci, which may contribute to heterosis. The results of the relative midparent heterosis and modes of inheritance of all investigated traits demonstrated that additive effects were the foundation of heterosis for complex traits in a hierarchical structure, and multiplicative. In this study, a small testcrossed rice population was constructed to investigate the formation mechanism of heterosis for traits.
Heterosis or hybrid vigor is a natural phenomenon whereby hybrid offspring of genetically diverse individuals display improved physical and functional characteristics relative to their parents. Plants free fulltext gibberellins and heterosis in. Click download or read online button to get manual for hybrid rice seed production book now. Jun 15, 2018 despite the great contributions of utilizing heterosis to crop productivity worldwide, the molecular mechanism of heterosis remains largely unexplored. Rice provides a good model crop for heterosis studies rice is the staple food crop currently feeding over half of the worlds population. Rice is a selfpollinating crop, even though strong heterosis is observed in their f 1 hybrids. East 19081909 studied the effects of inbreeding and outbreeding. Hybrid breeding methods are used in maize, sorghum, rice, sugar beet, onion, spinach, sunflowers, broccoli and to create a more psychoactive cannabis.
The latter was estimated in comparison to commercial varieties. 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. Heterosis is used to increase yields, uniformity, and vigor. The large sample size of the f 2 population and the high genotype density from wholegenome sequencing helped in a comprehensive identi. Plant breeders often cross different types of rice to produce hybrids with increased yields and other advantageous traits. In spite of the pervasive importance of heterosis, a complete understanding of its mechanisms has remained elusive. Sep 25, 2012 heterosis refers to the superior performance of hybrids relative to the parents. Manual for hybrid rice seed production download ebook pdf. Heterosis and hybrid rice breeding sant singh virmani. Heterosis, also known as hybrid vigor, is a wellknown phenomenon whereby hybrid offspring resulting from cross pollination exhibit greater vigor than either parent. Genetic analysis for the grain number heterosis of a.
Materials and methods this study was performed in the research farm of the university of agriculture peshawarpakistan, during the year 2011. In rice, altered regulation of gibberellic acid and abscisic acid biosynthesis genes can lead to hybrid vigor chen et al. Heterobeltiosis and standard heterosis were studied in 14 crosses between rice oryza sativa l. The successful commercialization of hybrid rice in many parts of the word is linked to the development. Heterosis o vigor hibrido by luis alberto chaponan rodriguez. Hybrid rice heterosis and genetic diversity of irri and. Hybrid rice varieties have been released from different countries with greater yield potential 15 to 20% than the commercial growing rice varieties under different environments yuan et al.
Utilization of heterosis has contributed tremendously to the increased productivity in many crops for decades. 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. The present study was focused on assessment of heterosis and heritability among f 1 rice hybrids for yield and yieldrelated traits. Genetic composition of yield heterosis in an elite rice hybrid. Ppt heterosis powerpoint presentation free to download. Around 293 and 302 million high quality pairedend reads of ajay and rajalaxmi, respectively, were generated and aligned against the. Heterosisandhybridriceih835082020 adobe acrobat reader dcdownload adobe acrobat reader dc ebook pdf. This study aims to identify restorers and maintainers, to estimate heterosis of hybrid rice, and to identify fertilityrestorer genes of f 2 populations. Genome sequencing and analysis of numerous wild rice and asian cultivated rice accessions have enabled the identification of genomewide.
Heritability and heterosis for yield and yield related traits. Rice is the most important food crop of the developing world and the demand for it is growing. Eight genotypes consisting three basmati varieties viz, basmati kasturi, basmati 370 and basmati with five manipur scented rice landraces viz, chakhao poireiton, chakhao, chakhao amubi, ching chakhao and chakhao angangba were crossed in 8x8 diallel fashion without recieprocal producing twenty eight f 1 hybrids and were evaluated to estimate mid parent heterosis for. Four associations with the phytohormone gibberellin ga indicate its involvement in the regulation of heterosis for shoot growth in maize, sorghum, wheat, rice, tomato and poplar.
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. The analysis of 31 test crosses revealed 6 restorers and 9 maintainers based on pollen fertility. Recent research on the mechanism of heterosis is important for crop. Corn maize nearly all field corn grown in most developed nations exhibits heterosis. Free pdf reader free and safe download free pdf reader latest version simple. Heritability and heterosis for yield and yield related. Heterosisandhybridricejf677932020 adobe acrobat reader dcdownload adobe acrobat reader dc ebook pdf. The genetic basis of heterosis for rice grain yield has remained largely uncharacterized. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudooverdominance. 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 genetics and exploitation of heterosis in crops. Book of abstracts the genetics and exploitation of heterosis in crops. Approximately 20 genomes of oryza species and several thousands of rice cultivars have been deeply sequenced or resequenced with lowfold coverage 9, 60, 121, 170. To examine the genetic basis of heterosis for yield in rice, here we generate. The analyses displayed a picture that accumulation of small advantages genomewide could explain the genetic basis of heterosis in this elite rice hybrid.
Pdf it is important to know the degree and direction of hybrid vigor for its commercial exploitation. With the advent of molecular markers great efforts were. Manual for hybrid rice seed production download ebook. Increasing grain yield is a longterm goal in crop breeding to meet the demand for global food security.
In this perspective, we consider that it might be useful to the field to abandon these. Rice has also become an excellent model system in plant biology research for monocotyledon species because of its many advantages relative to other cereals 12. Heterosis has been increasingly applied in crop production for nearly a century, with the aim of developing more vigorous, higher yielding and better performing cultivars. Despite its importance in maize production, we know surprisingly little about the genetic basis of heterosis. Thirty rice genotypes including 14 parents and 16 f 1 hybrids were replicated twice in a randomized complete block design rcbd. Pdf on oct 20, 2018, balaji thorat and others published heterosis in rice. Genetic composition of yield heterosis in an elite rice hybrid gang zhou, ying chen, wen yao, chengjun zhang, weibo xie, jinping hua1, yongzhong xing, jinghua xiao, and qifa zhang2 national key laboratory of crop genetic improvement and national centre of plant gene research wuhan, huazhong agricultural university. The crop was free from insect and disease infestation. With acrobat reader dc you can do more than just open and view pdf. To build predictive models for rice hybrids under different growth conditions, we measured the grain yield of two f 1 hybrid populations pop2012 and pop2015 and calculated betterparent heterosis for yield per plant bphypp for subsequent analysis table s1.
In recent years, unlocking the genetic diversity of species has provided insights into the genomics of rice domestication, heterosis, and complex traits. Ijms free fulltext differential expression of genes at. Research on heterosis, male sterility systems, outcrossing mechanisms. Determination of predictive variables for yield heterosis. Genetic analysis for the grain number heterosis of. Hb crosses hetero standard beltiosis % heterosis % 1 cha01ch1 28. China started hybrid rice research in 1964 and has been using it in commercial rice production since 1976. Coined the word heterosis to describe the increased vigor observed from heterozygosity. Strategies for utilizing heterosis in wheat, rice and oil seed brassica in india, pp. Heterosisandhybridriceih835082020 adobe acrobat reader. The genomics of oryza species provides insights into rice. Word converter free pdf to word converter has been designed to allow users to edit pdf. Hybrid rice exploits the phenomenon of hetrosis which can increase the yield potential over hyvs.
Heterosis refers to the superior performance of hybrids relative to the parents. These results suggest that dominance complementation is the major genetic basis of heterosis in rice. Dominance is the major genetic basis of heterosis in rice. The phenomenon has apparently been recognized in one form or another for centuries by various civilizations chen. Exploitation of heterosis in crops has contributed greatly to improvement in global food and energy production. Genetic composition of yield heterosis in an elite rice. Genetic diversity and its relationship to hybrid performance and. His work led to the formulation of the modern heterosis concept.
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