Study On Molecular Mapping Of Genic Male-sterile Genes Ms₁₄ And Agronomic Traits By SSR Market In Cotton

Cotton has a obvious heterosis. Three-line and two-line method and its seed production techniques, have been applied based on the male sterile line, so hybrid variety could be widely grown in china. Among all of the genic male-sterile genes, only Dong-A(ms14) and ms5ms6 lines have been utilized successfully in hybrid production of cotton,and ms14 was applied most widely in China. In this research we mapped the ms14 genes first by SSR markers using KA(Dong-A derived Lines) as experiment material, and also detected the QTLs of some agronomic traits including gland traits et al. This research will be helpful for future fine mapping of these genes and marker-assisted breeding of cotton. The results are as follows:1. We built a F2 population comprised of 180 individual plants with an upland cotton KA (ms14) as female parent, and 601588 as male parent. KA as the cultivar of an upland cotton is Xinluzhong 31's female parent with glandness and genic male-sterile; 601588 as the cultivar of a sea-island cotton is the male parent. Two thousand SSR markers were screened and 112 of them showing polymorphism between parents were selected to construct the genetic linkage map. The linkage map covers 968.9 cM, with equal to 17.44% of the full cotton genome. The map is comprised of 18 linkage groups, and a total of 76 markers with average distance of 16.7 cM between two markers. All of the linkage groups(LG1-LG17) except LG18 were corresponded to specific chromosomes through bridge markers.2. Fertility gene ms14 was linked with markers BNL3971 and NAU663 basing on BSA method, and all of them BNL3971 is closest to ms14 with 16.7 cM distance. According to published cotton gene map, ms14 gene was positioned on the Chr.2.3. There are detected four markers NAU1301b, NAU1301a, BNL4059 and JESPR300, and NAU1301b to be linked with Gland gene basing on BSA method and NAU1301b has the closest distance from the gland gene with 31.8 cM. The gland gene was located on Chr12.4. Eight possible QTLs were detected basing on six agronomic traits's data. Four of them were credible (LOD>2.5) , which are one QTLs of the first fruit nodes(FFN) located on Chr.21; one QTLs of the first branch height (FBH) on Chr.21; one QTLs of leaf length (LL) on Chr.8; and one QTLs of the leaf width (LW) on Chr.8. The R2 values of QTLs of FFN and LL are 34% and 11%, respectively. Thus the two QTLs were suggested as major QTLs.