Abstract: Cotton is the world’s most important natural textile fiber. With the changes in spinning technology, the improvement of cotton fiber quality is becoming extremely important. The combination of conventional breeding techniques with MAS (mo-lecular-assisted selection) will become a basic approach for cotton fiber improvement. In the present study, 3 458 SSR primer pairs were used to screen the polymorphic primers between Zhong 35 and Yumian 1, and 173 polymorphic primer pairs were ob-tained. The polymorphic primer pairs were used to genotype the 180 individual plants of F₂ population derived from (Zhong 35 × Yumian 1), and 178 loci were obtained. A genetic linkage map with 148 SSR loci and 36 linkage groups was constructed, and the linkage map covered a whole length of 1 309.2 cM with an average interval of 8.8 cM between two markers, accounting for 29.5% of the cotton genome. 28 out of 36 linkage groups were located on 20 chromosomes, and 8 linkage groups were not located on any chromosomes. The data of yield and fiber qualities of the 180 F₂ plants and F_2:3 family lines were used to detect QTLs by interval mapping, and 9 QTLs controlling yield and fiber quality were identified, including two QTLs for lint percent (LP), one for boll weight (BW), one for seed index (SD), one for fiber length (FL), two for fiber strength (FS), and two for fiber fineness (FF). The five QTLs, LP1, BW, SD, FL, and FS1, were located on chromosome 7, and the other four QTLs, LP2, FS2, FF1, and FF2, on chro-mosome 15, 21, 9, and 20, respectively. The favorable alleles of all five QTLs for fiber qualities originated from Yumian 1.

Key words: Upland cotton, Genetic linkage map, Yield, Fiber quality, QTL