Qtl Mapping Of Fiber Quality Traits In Sea-island Cotton

Sea-Island Cotton is one of the most important cultivated cotton species in the world,and has about 3% of total world's cotton production,which is indispensable raw materials in high-end textiles and special fabrics. With the advances in spinning technology and the needs of the people, the better fiber quality will be required.Traditional breeding methods, through hybridization, backcross and convergent hybridization in improving the quality of fibers have made great progress. However, because of the complexity of fiber quality traits and the choice of low efficiency,traditional breeding methods in the further improvement of fiber quality are considerable difficulty.With the rapid development of the Molecular Biology,the sea-island cotton fiber quality traits closely linked molecular markers will enable breeders to be able to track the important traits in the early stage of cotton growth or the early separation generations, so as to enhance the choice of the quality fiber efficiency.In this study, sea-island cotton varieties of the xinhai 3 and jiza82 built 190 F2: 3 family lines for the material. A sea-island cotton genetic linkage map was constructed with SSR markers and the main fiber quality traits of the sea-island cotton were to be identified a preliminary QTL. That lay a foundation for high-quality varieties of sea-island cotton marker-assisted selection and quality traits of the gene cloning. The mainly results were as following:1. By the analysis of fiber quality traits derived from sea-island xinhai 3 and jiza 82, the results showed that the indicators of fiber quality traits were in line with the normal distribution and were controlled by multiple genes, which showed they were quantitative trait inheritance. There was relevance among fiber quality traits. Between fiber length and fiber strength, fiber length uniformity was a significantly positive correlation, and short fiber index was significantly negative correlation. Between micronaire and fiber strength, fiber length uniformity was a significantly positive correlation.2. Apply 3800 pairs of cotton SSR markers to select primers from two parents of xinhai3 and jiza82. 81 pairs of clear and reproducible polymorphic SSR primers were selected. And use sea-island cotton varieties: xinhai 3 and jiza 82 hybrid F2 groups. Apply the method of genetic linkage analysis to analyse 81 marker loci, a sea-island cotton genome coverage of 14.09% of the genetic linkage map of molecular markers which including 18 linkage groups, 48 markers, 625.4cM length was established. The largest marking map was 53.8cM, the minimum was 0.3 cM, and the average spacing was 13.03cM. The number of each linkage group was 2.6.3. Based on composite interval mapping, a total of 5 greater effect QTLs were detected. One QTL, located on linkage group LG1, was identified for fiber length uniformity, explaining 38.8% of the fiber length uniformity variance. One QTL for fiber lelongation, located on linkage group LG1 was identify, explaining 5.7% of the fiber lelongation variance. One QTL for Micronaire, located on linkage group LG1, was identified, explaining 10.7% of the micronaire variance. One QTL for maturity index,located on linkage group LG1, was identified,explaining 8.5% of the maturity index variance.One QTL for spinnability coefficient,located on linkage group LG3,was identified,explaining 8.6% of the spinnability coefficient variance.