Mapping QTLs for fiber- and seed-related traits in Gossypium tomentosum CSSLs with a G. hirsutum background

Introducing the inherent genetic diversity of wild species into cultivars has become one of the hot topics in crop genetic breeding and genetic resource research. Fiber- and seed-related traits, which are critical to the global economy and people's livelihoods, are the principal focus of cotton breeding. Here, the wild cotton species Gossypium tomentosum was used to broaden the genetic basis of G. hirsutum and identify QTLs for fiber- and seed-related traits. A population of 559 chromosome segment substitution lines (CSSLs) was established with various chromosome segments from G. tomentosum in a G. hirsutum cultivar background. Totals of 72, 89, and 76 QTLs were identified for three yield traits, five fiber quality traits, and six cottonseed nutrient quality traits, respectively. Favorable alleles of 104 QTLs were contributed by G. tomentosum. Sixty-four QTLs were identified in two or more environments, and candidate genes for three of them were further identified. The results of this study contribute to further studies on the genetic basis of the morphogenesis of these economic traits, and indicate the great breeding potential of G. tomentosum for improving the fiber- and seed-related traits in G. hirsutum.