QTL Mapping of Fiber- and Seed-Related Traits in Chromosome Segment Substitution Lines Derived from × .

A narrow genetic basis limits further the improvement of modern cultivar. The abundant genetic diversity of wild species provides available resources to solve this dilemma. In the present study, a chromosome segment substitution line (CSSL) population including 553 individuals was established using accession 5-7 as the donor parent and cultivar CCRI35 as the recipient parent. After constructing a high-density genetic map with the BC population, the genotype and phenotype of the CSSL population were investigated. A total of 235 QTLs, including 104 QTLs for fiber-related traits and 132 QTLs for seed-related traits, were identified from four environments. Among these QTLs, twenty-seven QTLs were identified in two or more environments, and twenty-five QTL clusters consisted of 114 QTLs. Moreover, we identified three candidate genes for three stable QTLs, including () and () for lint percentage, and () for seed index or oil content. These results pave way for understanding the molecular regulatory mechanism of fiber and seed development and would provide valuable information for marker-assisted genetic improvement in cotton.