Proteomic Analysis Of Cotton Fiber Development And Genetic Diversity Of127Gossypium Barbadense L

Xinjiang cotton area has a unique natural ecological conditions, the production of cotton has uniquenatural advantage. Cotton production need to have good quality seed enough to mention the foundation,which requires rich germplasm resource. In the experiment,127copies of Sea Island cotton (Gossypiumbarbadense L.) germplasm resources from Xinjiang、the former Soviet Union、mainland of China and theUnited States introduced were studied by combining phenotypic traits with molecular marker analysis, theresults are as following:(1)A quantitative proteomic approach with isobaric labeling (iTRAQ) was applied to evaluate theprotein expression differences between Sea Island cotton and uplands cotton,1574differentially expressedproteins were identified. The deduced peptide sequences of protein comprised5-33amino acid residueswith the same predicted molecular weights of about30-70kDa.(2)The result indicated that there were total237differentially expressed proteins discovered in SeaIsland cotton, among which126up-regulated,111down-regulated. There were total180differentiallyexpressed proteins discovered in uplands cotton, and total235differentially expressed proteins discoveredbetween Sea Island cotton and uplands cotton. These studies could give us a deeper understanding of cottonin providing the basis for the gene cloning related to yield and quality trait, which could lay soundfoundation for the future breeding in quality cotton.(3)In order to estimate the level of genetic diversity of127germplasm resources of Sea Island cotton,the genetic diversity of six yield and5quality characters of the127germplasm resources of Sea Islandcotton were analyzed. The results indicated that, among the elevev phenotypic characters of the127germplasm had the significant genetic deference, and the range of the fiber length of Chinese cottoncultivars and lines were higher than those abroad cotton cultivars and lines (P<0.05). The growth rate ofChinese cotton cultivars and lines were lower than those abroad cotton cultivars and lines (P<0.05)(4)Using the software Powermarker3.25and Structure2.0, based on Nei’s genetic distance, the clusteranalysis that the127cotton cultivars and lines into3main groups. Group I were made up of the former Soviet accessions and group2were made up of the Chinese cotton accessions. Meantime, Chinese cottoncultivars and lines and abroad cotton cultivars and lines were relatively independent. The resultsdemonstrated that breeders can breed new cotton variety by takeing full advantage of genetic differencesamong these two different groups.(5)Using48SSR primers,166allele’s loci were detected in127cotton cultivars and lines. Theaverage number of alleles per SSR was3.5with a range from1to10. The diversity information index of127cotton cultivars and lines were0.4144。The diversity information index from highest to lowest is theTurban varieties, the Nongyishi varieties, the Bazhou varieties and the Xinjiang Academy of AgricultureSciences varieties.(6)In this study, the genetic diversity of six yield and5quality characters of the127germplasmresources of Sea Island cotton were used to association analysis. Ten markers were found to associate withthe eight traits; the average number of eacher SSR marker was2.1with a range from1to four. The SSRmarkers BNL252and SHIN0419showed highly significant (P<0.05) association with the bell chambernumber and explained24.7%and24.2%of phenotypic variance, respectively. The SSR markers BNL252,SHIN0419and DC30007showed highly significant (P<0.05) association with most of yield and qualitycharacters, and explained higher phenotypic variance. The results demonstrated that BNL252, SHIN0419and DC30007are efficient and can be used in marker-assisted selection (MAS) targeting.