Genetic Analysis Diversity Of127Sea Island Cotton

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. so far, more than300copies of the cotton germplasm resources ofSea Island cotton be collected and saved. In the experiment,127copies of germplasm resources fromXinjiang、the former Soviet Union、mainland of China and the United States introduced were studied bycombining phenotypic traits with molecular marker analysis, the results are as following:1、 The phenotypic traits of the127germplasm resources of Sea Island cotton was relatively abundant,the genetic diversity index of the boll number was the highest in16phenotypic traits, which reached2.6,followed by plant height and node number. The plant gland was the lowest, which was0.25. The diversityinformation index from highest to lowest is the Xinjiang varieties, the former Soviet Union varieties, theinnovation germplasm materials, mainland varieties, other varieties and the United States materials.2、Phenotypic cluster analysis indicated that some varieties from different places were clustered intoone group, the reason might be a cross between varieties and environmental factors, but the majorityvarieties with the same origin and similar genetic background information can better together as a class.clustering result was accord with the evolution trend of the genetic background.3、207pairs of SSR primers were screened,49pairs of polymorphic primers genetic diversity indexwas calculated using SSR molecular marker data. The order of genetic diversity index from largest tosmallest is the former Soviet Union varieties, Xinjiang varieties, inland varieties, the innovation germplasmmaterials, the United States materials and other varieties. The order is different from the order ofphenotypic traits.4、SSR analysis showed that more Sea Island cotton germplasm resourcts clustered into one category,which indicated germplasm genetic base of Sea Island cotton is relatively narrow. In the early, Xinjiangsalf-sterile validation varieties, as the center to the dges, in the later, genetic relationships of varietiesincreased gradually through continuous introduction and germplasm innovation. The results of populationstructure analysis and calculation showed that127Sea Island cotton germplasm resources can be dividedinto three subsets, further confirmed the problem the saved Sea Island cotton germplasm populationstructure is too single, the genetic background is relatively narrow.