Heterosis in rice pdf

However, there has been no report on heterosis in the number of differentiated, degenerated spikelets in f 1 hybrid rice. Dominance is the major genetic basis of heterosis in rice. Correlation coefficients between the performances of rils, testcross f 1 s, and are shown in table 3. Prospects of utilization of intersubspecific heterosis. Heterosis or hybrid vigor is a phenomenon in which a hybrid progeny exhibits superior performance compared to their parental inbred lines. Various models have been posited to explain heterosis, including dominance, overdominance, and pseudooverdominance. In spite of the pervasive importance of heterosis, a complete understanding of its mechanisms has remained elusive. Ppt heterosis powerpoint presentation free to view id. Combining ability is a measure for selecting elite parents that.

Root morphology was improved in a latestage vigor super rice cultivar root morphology was improved in a latestage vigor super rice cultivar. Heterosis is used to increase yields, uniformity, and vigor. The firstgeneration offspring generally show, in greater measure, the desired characteristics of both parents. Abstract two cms lines, ir69616a and ir70369a were crossed with 60001 a fine grain aromatic advance line and basmati 385 a commercial basmati variety. Exploitation of heterosis in crops has contributed greatly to improvement in global food and energy production. 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. It has been over 100 years since the discovery of the. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of plant breeding. Heterosis results in the phenotypic superiority of a hybrid over its parents with respect to traits such as growth rate, reproductive success and yield. The phenomenon that the heterozygous first filial f 1 generation often has better performance than its homozygous parents is known as heterosis or hybrid vigour1,2,3. Post graduate college, jaunpur 222 002 uttar pradesh, india. The genomics of oryza species provides insights into rice. In fact, the biological basis of heterosis is considered by some scientists to be inadequately defined.

Understanding genetic variability and mode of gene action for agronomic and yield related traits is important in formulation of effective rice breeding program for genetic enhancement of grain yield. Despite the successful agronomic exploitation of heterosis in several crops, especially hybrid rice and hybrid maize, the molecular mechanisms underlying crop heterosis. Area devoted to hybrid rice is growing rapidly in each of these countries. Heterosis, the increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents.

Mar 03, 2020 the application of heterosis hybrid vigor in hybrid rice since the 1970s has tremendously improved rice productivity worldwide. In this article we will discuss about heterosis or hybrid vigour. Jul 30, 2017 heterosis can be defend as the superiority of f hybrid over both the parents in terms of yield and some other character. The situation is similar in rice and tomato, in which most heterotic phenotypes are associated with yield 10, 23. Transcriptomic analysis reveals overdominance playing a.

Genetic analysis for the grain number heterosis of a. Despite the importance of heterosis in maize and the plethora of research done on heterosis, little is known empirically about the underlying genetic and related physiological basis of heterosis. 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. To examine the genetic basis of heterosis for yield in rice, here we generate, sequence and record the phenotypes of 10,074 f 2 lines from 17 representative hybrid rice crosses. Correlation between the performances of rils, testcross f 1 s, and midparent heterosis. Experimental details the two cytoplasmic male sterile cms lines viz. Genomic analysis of hybrid rice varieties reveals numerous superior alleles that contribute to heterosis. The ypps of parents from the two populations were significantly.

To systematically exploit heterosis in hybrid breeding, the concept of heterotic groups and patterns was suggested. The latter was estimated in comparison to commercial varieties. Corn maize nearly all field corn grown in most developed nations exhibits heterosis. Hybrid breeding methods are used in maize, sorghum, rice, sugar beet, onion, spinach, sunflowers, broccoli and to create a more psychoactive cannabis. 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.

Determination of predictive variables for yield heterosis. Hybrid vigor is defined by mechanisms such as dominant. Sixteen f 1 hybrids and their 14 parents were planted in a randomized complete block design using two replications at the university of agriculture peshawar, during 2011 rice crop growing season. Heterosis is a multigenic complex trait and can be extrapolated as the sum total of many physiological and phenotypic traits. Heterosis or hybrid vigor results in a hybrids phenotypic superiority over its founder parents for quantitative and qualitative traits. Here, by genome analysis, we found that breeders introduced different introgressed exogenous genomes of other rice subpopulations to construct male and female parents.

Heterosis and inheritance of fertilityrestorer genes in rice. 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. The application of heterosis hybrid vigor in hybrid rice since the 1970s has tremendously improved rice productivity worldwide. Identification of transcriptome snps for assessing allelespecific gene expression in a superhybrid rice xieyou9308. Genetic composition of yield heterosis in an elite rice hybrid. Since then, heterosis is a major concern for both biologists and breeders. Exploring the molecular basis of heterosis for plant breeding. Is the major genetic basis of heterosis in rice as. The present research was performed to assess genetic variability and heterosis among 30 rice genotypes for yield and yield associated traits. Heterosis definition types of heterosis heterosis in. Comparative transcriptional profiling and preliminary.

Genetic analysis for the grain number heterosis of a superhybrid rice. The development of heterotic crops, especially those for hybrid rice and maize, is one of the most important applications of genetics in agriculture, and now over half of the rice and maize production worldwide is from hybrid. 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. Heterosis is a major yield factor in all breeding categories except line breeding schnell, 1982. The book contains a wealth of useful information for practicing hybrid rice breeders, seed producers, researchers, and students of. Transcriptome analysis of rice root heterosis by rnaseq bmc genomics, jan 20 rongrong zhai, yue feng, huimin wang, xiaodeng zhan, xihong shen, weiming wu, yingxin zhang, daibo chen, gaoxing dai, zhanlie yang, et al. Heterosis and hybrid rice breeding sant singh virmani. Heterosis is observed in almost every crop species studied, the application of this phenomenon for its commercial exploitation depends on. Research on heterosis, male sterility systems, outcrossing mechanisms. Heterobeltiosis and standard heterosis were studied in 14 crosses between rice oryza sativa l. Transcriptome analysis of rice root heterosis by rnaseq. 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 china, the. 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.

The converse or complement to inbreeding depression in which the value d a. Analysis of the genetic basis of yield heterosis in rice was conducted by quantitative trait locus mapping using a set of 204 recombinant inbred lines rils, its testcross population, and midparent heterosis dataset. At the same time, japonica hybrid rice has been continuously studied in china, and a large number of japonica hybrid rice varieties have been bred. Genomic architecture of heterosis for yield traits in rice. Heterosis has been widely exploited to increase the productivity of crop plants for many decades stuber, 1994. Two conclusions concerning the loci associated with inbreeding depression and heterosis in rice were reached from our results. We have reported the differences in the number of differentiated, degenerated, and surviving spikelets per panicle and their relationships among different cultivars yao et al. Pdf heterosis for yield and yield components in rice. Naomi miyaji, ryo fujimoto, in advances in botanical research, 2018. Ir36 and ir42 yield 45 tha in wet season trials and 78 tha in dry season trials.

The successful application of heterosis in hybrid rice has dramatically improved rice productivity, but the genetic mechanism for heterosis in the hybrid rice remains unclear. Production and heterosis analysis of rice autotetraploid. 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. These results suggest that dominance complementation is the major genetic basis of heterosis in rice. 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. These crosses showed marked variations in the expression of heterobeltiosis and standard heterosis for yield and yield components. Transcriptome analysis of rice root heterosis by rnaseq pdf. Pdf combining ability and heterosis for agronomic and yield. However, the application of japonica hybrid rice is limited because of its weak heterosis. Significant positive correlations between the rils and testcross f 1 s were observed for all the traits. In light of the pressing problem of producing everincreasing amounts of food on less arable land, this publication on the history and current knowledge of.

The f 1 were left to produce f 2 seeds during the 2011. Fine grain aromatic line, 60001 and basmati 385 were used as testers. The restoration of phenotypic performance by crossing inbred lines to produce a hybrid is called heterosis. In this study, a small testcrossed rice population was constructed to investigate the formation mechanism of heterosis for traits. Dominance is the major genetic basis of heterosis in rice as. Is the major genetic basis of heterosis in rice as revealed.

This hybrid vigor is determined by nonmutually exclusive mechanisms, including dominance complementation, overdominance and epistasis. Dissecting combining ability effect in a rice nciiiii. Heterosis can be defend as the superiority of f hybrid over both the parents in terms of yield and some other character or. Overdominant epistatic loci are the primary genetic basis of. These observations tend to implicate epistasis and overdominance, rather than dominance, as the major genetic basis of heterosis in rice. Pdf combining ability and heterosis for agronomic and. Heterosis or hybrid vigor refers to the phenomenon in which hybrids outperform their inbred parents in yield, biomass, biotic and abiotic stress tolerance, or other traits. Metabolomebased prediction of yield heterosis contributes to. The correlation coefficient was the highest for tgw 0. 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. The extent of heterosis identified in our study is comparable to that from the research by zhang et al. Heterosis is the foundation of the great success of hybrid rice in china.

To systematically exploit heterosis in hybrid breeding. We classify modern hybrid rice varieties into three groups, representing different hybrid breeding systems. 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. But how breeders construct hybrid parents to obtain hybrid rice heterosis remains unclear. Comparative transcriptional profiling and preliminary study. Hierarchical additive effects on heterosis in rice oryza. Heterosis has been known since the art of hybridization came into. Rice is the staple food crop feeding over half of the world s population. Genetic variability and heterosis among rice genotypes for. Genetic analysis for the grain number heterosis of. Heterosis breeding in rice for quantitative traits 545 82. F 1 hybrid seed production system is used for many crops and vegetables because of the high yield due to hybrid vigor. Divergent selection and genetic introgression shape the. Detection of qtls for yield heterosis in rice using a ril.

Provided here is a concise account of hybrid breeding in rice, a newly deployed breeding approach to increase the yield. Rice is the most important food crop of the developing world and the demand for it is growing. Rice, superhybrid 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. 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. In the noncrop plant arabidopsis, heterosis is mainly reflected in seedling biomass, although an accurate assessment of hybrid vigor for reproductive traits is still lacking 24, 25, 26. Overdominant epistatic loci are the primary genetic basis. Plant and animal breeders exploit heterosis by mating two different purebred lines that have certain desirable traits. Ppt heterosis powerpoint presentation free to view. Pdf heterosis and combining ability analysis in basmati. When two homozygous inbreeds a true breeding line obtained by continuous inbreeding of genetically unlike constituents are crossed together, the resulting hybrids obtained from. 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, wuhan 430070, china. Hybrid rice exploits the phenomenon of hetrosis which can increase the yield potential over hyvs. In this perspective, we consider that it might be useful to the field to abandon these. First, most qtl associated with inbreeding depression and heterosis in rice appeared to be involved in epistasis.

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. Dissecting combining ability effect in a rice nciiiii population provides insights into heterosis in indicajaponica cross hao zhou, duo xia, jing zeng, gonghao jiang and yuqing he abstract background. Research article detection of qtls for yield heterosis in. The analyses displayed a picture that accumulation of small advantages genomewide could explain the genetic basis of heterosis in this elite rice hybrid. Now, the acreage of hybrid rice takes more than half of the total rice area in china and superior hybrid rice has been showing a increasing contribution to the grain yield normile, 2008. Heterosis in numbers of differentiated, degenerated, and.

Heterosis,orhybridvigor,referstothesuperiorperformance of hybrids relative to their parents. This increased productivity or superiority over the parents is known as heterosis or hybrid vigor or. 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. Evenwithinthesameplantspecies,themagnitude of heterosis is quite different. Heterotic genes responsible for elevating crop yields are now being sought using genomics, particularly. Metabolomebased prediction of yield heterosis contributes. In this study, we generated two populations of rice f 1 hybrids with presentday commercial hybrid parents, genotyped the parents with 50k snp chip and genome resequencing, and recorded the phenotype of. More branches per panicle and more grains per branch.

Heterosis or hybrid vigour is a major reason for the success of the maize industry as well as for recent advances in yield potential in rice. It plays an important role for enhancing crop yield. Now a large research project coled by the chinese academy of agricultural sciences has dissected the genetic architecture underpinning this hybrid success. Second, most 90% qtl contributing to heterosis appeared to be overdominant. Heterosis in f 1 rice hybrids article pdf available in acoustics, speech, and signal processing newsletter, ieee 24 january 2007 with 551 reads how we measure reads. Currently, rice hybrids are widely adopted in many countries, especially in china where hybrid rice varieties occupy % of the.