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Joshi, Suchitra; Bhave, S. G.; Chowdari, Kodavali V.; Apte, G. S.; Dhonukshe, B. L.; Lalitha, K.; Ranjekar, P. K.; Gupta, Vidya S.

doi:10.1023/a:1010293325482

Cited by 33 publications

(15 citation statements)

References 40 publications

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“…Thus authors reiterated that significant difference between the above studies may be used for prediction of heterosis in the silkworm breeding programme similar to the reports of plant breeding programmes [12,16,17] . The optimum level of genetic distance is necessary to obtain heterosis.…”

Section: Resultsmentioning

confidence: 65%

Genetic Distance and Heterosis through Evaluation Index in the Silkworm, Bombyx mori (L.)

Talebi¹

2009

American Journal of Applied Sciences

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Problem statement: Synthesis of new-gene combinations by genetic manipulation is one of the powerful tools in exploiting the commercial qualities of plants and animals. Hybrid performance is evaluated from extensive yield trials that are costly and time consuming. Approach: Four silkworm races belonging to two different voltine groups (two multivoltine races namely Pure Mysore and Nistari and two bivoltine races namely C 108 and NB 4 D 2 ) and the twelve regular and reciprocal hybrids derived from them were reared under standard laboratory condition analyzing six quantitative traits namely cocoon weight, shell weight, shell ratio, filament length, denier and renditta. The data of the pure races was analysed for the estimation of evaluation index to study the genetic divergence between the races, where as evaluation index, heterosis and overdominance effects were studied in twelve hybrid combinations. Results: Varied heterotic effects were observed for different traits for hybrid combination. Cocoon weight and shell weight has maximum heterosis over the mid parent in Pure Mysore × Nistari (27 and 42% respectively), whereas C 108 × Nistari have shown maximum shell ratio (30%) among the hybrids. The maximum filament length for heterosis was observed in the Nistari × Pure Mysore. Heterosis for cocoon weight, shell weight, shell ratio, filament length, denier and renditta based on evaluation index confirmed the above results. Conclusion: The investigation indicates that optimum level of genetic divergence between parents is necessary to obtain heterosis in F 1 generation.

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Section: Resultsmentioning

confidence: 65%

Genetic Distance and Heterosis through Evaluation Index in the Silkworm, Bombyx mori (L.)

Talebi¹

2009

American Journal of Applied Sciences

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“…plus the best linear unbiased prediction (BLUP), some scientists identified marker loci associated with quantitative trait loci for hybrid performance or specific combining ability (SCA) in maize and rice [4]–[8], [16]. These studies showed the high potential of joint analyses of hybrids and parental inbred lines for the prediction of performance of untested hybrids.…”

Section: Introductionmentioning

confidence: 99%

QTL Mapping of Combining Ability and Heterosis of Agronomic Traits in Rice Backcross Recombinant Inbred Lines and Hybrid Crosses

Luo

et al. 2012

PLoS ONE

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BackgroundCombining ability effects are very effective genetic parameters in deciding the next phase of breeding programs. Although some breeding strategies on the basis of evaluating combining ability have been utilized extensively in hybrid breeding, little is known about the genetic basis of combining ability. Combining ability is a complex trait that is controlled by polygenes. With the advent and development of molecular markers, it is feasible to evaluate the genetic bases of combining ability and heterosis of elite rice hybrids through QTL analysis.Methodology/Principal FindingsIn the present study, we first developed a QTL-mapping method for dissecting combining ability and heterosis of agronomic traits. With three testcross populations and a BCRIL population in rice, biometric and QTL analyses were conducted for ten agronomic traits. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and non-additive effects on expression levels. A large number of additive effect QTLs associated with performance per se of BCRIL and general combining ability, and dominant effect QTLs associated with special combining ability and heterosis were identified for the ten traits.Conclusions/SignificanceThe combining ability of agronomic traits could be analyzed by the QTL mapping method. The characteristics revealed by the QTLs for combining ability of agronomic traits were similar with those by multitudinous QTLs for agronomic traits with performance per se of BCRIL. Several QTLs (1–6 in this study) were identified for each trait for combining ability. It demonstrated that some of the QTLs were pleiotropic or linked tightly with each other. The identification of QTLs responsible for combining ability and heterosis in the present study provides valuable information for dissecting genetic basis of combining ability.

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“…Many studies investigated the relation between DNA-marker variation of parents and heterosis as expressed by their hybrid. For example, in maize, genetic distance between parents was strongly correlated to heterosis of their hybrid (20). It should be noted, however, that other studies reported low or no correlation at all between marker distance and yield, and it is well accepted that this association depends, at least in part, on the type of crop and the germ plasm being used.…”

Section: Resultsmentioning

confidence: 98%

Overdominant quantitative trait loci for yield and fitness in tomato

Semel

Nissenbaum²,

Menda³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

266

240

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Heterosis, or hybrid vigor, is a major genetic force that contributes to world food production. The genetic basis of heterosis is not clear, and the importance of loci with overdominant (ODO) effects is debated. One problem has been the use of whole-genome segregating populations, where interactions often mask the effects of individual loci. To assess the contribution of ODO to heterosis in the absence of epistasis, we carried out quantitative genetic and phenotypic analyses on a population of tomato (Solanum lycopersicum) introgression lines (ILs), which carry single marker-defined chromosome segments from the distantly related wild species Solanum pennellii. The ILs revealed 841 quantitative trait loci (QTL) for 35 diverse traits measured in the field on homozygous and heterozygous plants. ILs showing greater reproductive fitness were characterized by the prevalence of ODO QTL, which were virtually absent for the nonreproductive traits. ODO can result from true ODO due to allelic interactions of a single gene or from pseudoODO that involves linked loci with dominant alleles in repulsion. The fact that we detected dominant and recessive QTL for all phenotypic categories but ODO only for the reproductive traits indicates that pseudoODO due to random linkage is unlikely to explain heterosis in the ILs. Thus, we favor the true ODO model involving a single functional Mendelian locus. We propose that the alliance of ODO QTL with higher reproductive fitness was selected for in evolution and was domesticated by man to improve yields of crop plants.heterosis ͉ hybrid vigor ͉ domestication ͉ reproductive barriers ͉ breeding

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Cited by 33 publications

References 40 publications

Genetic Distance and Heterosis through Evaluation Index in the Silkworm, Bombyx mori (L.)

Genetic Distance and Heterosis through Evaluation Index in the Silkworm, Bombyx mori (L.)

QTL Mapping of Combining Ability and Heterosis of Agronomic Traits in Rice Backcross Recombinant Inbred Lines and Hybrid Crosses

Overdominant quantitative trait loci for yield and fitness in tomato

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