Author
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Saha, Sukumar |
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WU, JIXIANG - South Dakota State University |
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Jenkins, Johnie |
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McCarty, Jack |
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STELLY, DAVID - Texas A&M University |
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/10/2012 Publication Date: 1/1/2013 Citation: Saha, S., Wu, J., Jenkins, J.N., McCarty Jr., J.C., Stelly, D.M. 2013. Interspecific chromosomal effects on agronomic traits in Gossypium hirsutum by AD analysis using intermated G. barbadense chromosome substitution lines. Theoretical and Applied Genetics. 126:109-117. Interpretive Summary: Exotic germplasm is a likely source of new and valuable genes capable of increasing yield and other complex agronomic traits important to cotton improvement. The cotton breeder faces many difficulties in the process of introgressing G. barbadense genes to improve Upland cotton because of genomic incompatibility between these two species. Recently we have released several backcrossed (BC5) G. barbadense chromosome or chromosome arm substitution lines (CS-B). The CS-B lines are expectedly quasi-isogenic to each other, except that each line differs by the replacement of a specific homologous pair of chromosomes or chromosome segments from the donor alien species. These CS-B lines are useful tools to complement conventional methods of interspecific introgression and discovery of important traits associated with chromosome or chromosome arm of the alien species. Here we reported on the chromosomal effects of lint percentage (LP), boll weight (BW), seedcotton yield (YLD) and lint yield (LY) in chromosome substitution barbadense (CS-B) lines based on the interaction of alleles located on two alien substituted chromosomes versus one alien substituted chromosome using a partial diallel mating design of selected CS-B lines (CS-B05sh, CS-B06, CS-B09, CS-B10, CS-B12, CS-B17 and CS-B18). Results were analyzed using AD genetic model, which detected highly significant additive and dominance genetic effects associated with the respective substituted chromosome or chromosome arm of CS-B lines on the four agronomic traits. All of the CS-B lines had significant additive effects with boll weight and lint percentage. CS-B10 had the highest additive effects for lint percentage, seedcotton and lint yield among all of the lines including both donor and recurrent parents. Over 50% of the CS-B lines (CS-B06, CS-B09, CS-B10, CS-B17) had greater additive genetic effects on lint yield and over 40% of the CS-B lines (CS-B06, CS-B10, CS-B17) had superior additive genetic effects on seedcotton yield than TM-1. G. barbadense is well known as a unique source of genetic variation for improving fiber qualities, but it has rarely been used for the genetic improvement of agronomic traits. Here we report on the discovery of some cryptic novel genes of G. barbadense with potential of improving agronomic traits including seedcotton and lint yield. Technical Abstract: The untapped potential of the beneficial alleles from G. barbadense has not been well utilized in Upland (G. hirsutum) cotton breeding programs. This is primarily due to genomic incompatibility and technical challenges associated with conventional methods of interspecific introgression. In this study, we have used a hypoaneuploid-based chromosome substitution line as a means for systematically introgressing G. barbadense doubled-haploid line ‘3-79’ germplasm into a common Upland genetic background, inbred ‘TM-1’. We reported on the chromosomal effects lint percentage (LP), boll weight (BW), seedcotton yield (YLD) and lint yield (LY) in chromosome substitution barbadense (CS-B) lines based on the interaction of alleles located on two alien substituted chromosomes versus one alien substituted chromosome using a partial diallel mating design of selected CS-B lines (CS-B05sh, CS-B06, CS-B09, CS-B10, CS-B12, CS-B17 and CS-B18). Among these parents, CS-B09 and CS-B10 were reported for the first time. Data were analyzed using AD genetic model, which revealed highly significant additive and dominance effects on the four agronomic traits associated with the respective substituted chromosome or chromosome arm of CS-B lines. 3-79, the donor parent, has the lowest additive effect for all of the agronomic traits. All of the CS-B lines had significant additive effects with boll weight and lint percentage. CS-B10 had the highest additive effects for lint percentage, seedcotton and lint yield among all of the lines including both donor and recurrent parents showing a transgressive genetic mode of inheritance for these traits. Over 50% of the CS-B lines (CS-B06, CS-B09, CS-B10, CS-B17) had greater additive genetic effects on lint yield and over 40% of the CS-B lines (CS-B06, CS-B10, CS-B17) had superior additive genetic effects on seedcotton yield than TM-1. The 3-79 line had the highest dominance effects for boll weight (0.513g) and CS-B10 had the lowest dominance effect for boll weight (-0.702). Some major antagonistic genetic effects for the agronomic traits were present with most of the substituted chromosomes and chromosome arms, a finding suggesting their recalcitrance to conventional breeding efforts. The results revealed that the substituted chromosomes and arms of 3-79 carried some cryptic beneficial alleles with potential to improve agronomic traits including yield, whose effects were masked at the whole genome level in 3-79. |