利用3458对SSR引物筛选陆地棉中棉所35和渝棉1号间的多态性引物,获得173对。以多态性引物检测(渝棉1号×中棉所35)F2群体180个单株的标记基因型,共获得178个标记位点。构建的遗传连锁图谱包括148个标记,36个连锁群,总长1309.2cM,标记间平均距离8.8cM,覆盖棉花基因组的29.5%。36个连锁群中的28个分别被定位于20条染色体,8个连锁群未定位于染色体。以渝棉1号×中棉所35的F2、F2:3群体的产量、纤维品质性状鉴定结果,利用区间作图方法,检测到4个产量性状QTL,即2个衣分(LP)、1个铃重(BW)、1个籽指(SD);5个纤维品质性状QTL,即1个纤维长度(FL)、2个纤维比强度(FS)和2个纤维细度(FF)。LP1、BW、SD、FL和FS1被定位于第7染色体,LP2、FS2、FF1和FF2被分别位于第15、21、9和20染色体。5个纤维品质QTL的有利等位基因均来源于渝棉1号。
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 obtained. 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 F2:3 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 chromosome 15, 21, 9, and 20, respectively. The favorable alleles of all five QTLs for fiber qualities originated from Yumian 1.