Genetic dissection of lint percentage and seed cotton yield in exotic x elite upland cotton crosses using population-specific and joint population analysis

Abstract

Limited genetic diversity for fiber quality and yield traits in the improved gene pool for Upland cotton motivates the exploration of exotic materials. In the present study, we carried out QTL mapping for 2 fiber yield components in five BC 1 F 2 and one F 3 resembling intermated population(s) involving 5 ‘converted’ exotic lines of Upland cotton and an elite cultivar “DES56,” as a common parent in all populations. The results indicated a higher frequency of dominant QTLs than additive QTLs. However, the prevalence of negative heterotic effects shows few opportunities to utilize these exotic lines for hybrid production. Most of the dominant QTLs were overdominant. In addition, all additive QTLs for lint percentage indicated the DES56 allele to be superior. These results suggest that selection practices need to be carried out in the later generations along with the implementation of precise marker-assisted selection to avoid the undesirable heterotic effects of these regions and reduce the linkage drag from undesirable alleles in the exotic segments. Moreover, the population-specific analysis and joint analysis showed the inflation of QTL parameters with a decrease in sample size, indicating the importance of larger sample sizes in mapping populations. Overall, the potential for using these exotic race stocks for hybrid production targeting yield components is limited.

Bibliographic Information