Abstract:

【Objective】The aim of this study was to construct a DNA fingerprinting database of 32 cotton major cultivars from three main cotton regions (including eight main cotton production provinces), and the genetic diversity was analyzed based on simple sequence repeats (SSR).【Method】Thirty six evenly distributed SSR primer pairs with high polymorphisms and good repeatability were successfully screened out from 214 candidates to construct the fingerprinting database.【Result】Among the 32 varieties, 36 primer pairs had 142 polymorphic genotypes, and 3.94 genotypes were detected by each SSR primer pair on an average with the range from 2 to11. Ten cultivars had specific genotypes by 9 primer pairs. Thirty two major cultivars could be identified by 5 primer combinations at least. The genetic diversity analyzed by the software of NTSYS-pc V 2.10 indicated that Yangtze River valley cotton region had the highest polymorphic level, followed by Xinjiang, and the lowest was the varieties from the Yellow River valley. The genetic basis of conventional cultivars was narrower than that of hybrids. 【Conclusion】 Core primer combination method is better than distinct band method for the construction of DNA fingerprinting of cotton major cultivars in China. The genetic relationship of the cotton cultivars derived from the same district is similar to a certain extent.

Key words: cotton, major cultivar, SSR, DNA fingerprinting, genetic diversity