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棉 花 学 报 Cotton Science 2008，20(3)：163-169
Tagging and Mapping of QTL for Yield and its Components in Upland Cotton（Gossypium hirsutum L.） Population with Varied Lint Percentage Abstract：A genetic linkage map with 88 loci from 6111 pair SSR primers was constructed using 188 F2 plants obtained from a cross between two upland cotton cultivars, which differ remarkably in lint percentage and have relatively high levels of DNA marker polymorphism. The map covered 666.7 cM with an average distance of 7.57 cM between two markers, or approximately 14.9% of the recombination length of the cotton genome. Composite interval mapping was used to identify the quantitative trait loci (QTL) in F2 and F2：3 family lines. Eighteen QTLs for yield and its components were identified including two QTLs for lint percentage, four QTLs for seed yield, four QTLs for lint yield, two QTLs for lint index, three QTLs for bolls per plant, two QTLs for boll size, and one QTL for seed index. These QTLs separately explained 6.9% ～ 16.9%, 5.6%～16.2%, 4.8%～15.6%, 7.7%～13.3%, 8.2%～11.6%, 6.1%～7%, and 6.6% of the phenotypic variance. Different QTLs affecting yield traits were detected within the same chromosome region, suggesting that genes controlling yield traits may be linked closely or the result of pleiotropy. The QTLs controlling yield and its components were mainly dominant and overdominant. The molecular markers linked closely to the major QTLs may be used in MAS (marker-assisted selection) to improve cotton yield and its components.
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