Abstract: Cotton fiber is one of known natural resources comprising the highest purity cellulose. It plays an important role in the textile industry worldwide. With acceleration of spinning speeds and improvement of people’s living level, the demand of improving cotton fiber qualities is getting stronger and stronger. Using molecular marker linked tightly with main QTL of super quality to make marker-assisted selection is the most direct and effective method to improve fiber quality of commercial cultivars quickly. In this paper, a genetic linkage map was constructed by the F₂ segregation population derived from a cross between Yumian 1, a high quality cotton cultivar, and TM^-1, a genetic standard line. We identified 178 polymorphic loci with 5 544 pairs of SSR primers. The genetic map with 138 loci was constructed, which had a whole length of 959.7 cM and covered 19% of the whole cotton genome. Moreover, the fiber characteristics of the F₂ plants and the F₃ family lines were analyzed by composite interval mapping (CIM) and 12 putative quantitative trait loci (QTLs) were detected for 5 traits, 1 for fiber length, 4 for fiber strength, 3 for fiber fineness, 3 for fiber uniformity and 1 for fiber elongation. These QTLs explained their corresponding phenotypic variations with 6.1%, 5.31%–14.62%, 7.88%–19.17%, 7.4%–11.71%, and 8.26%, respectively. Many QTLs associate with fiber quality located in Chromosome 23 and Chromosome 24 through chromosome tagging analysis combining with different elite fiber lines in the lab. The result provides references for utilizing reasonably Yumian1 in cotton breeding improvement.

Key words: Upland cotton, Fiber quality, QTLs, Molecular marker