中国棉花主栽品种DNA指纹图谱构建及SSR标记遗传多样性分析

Construction of DNA Fingerprinting and Analysis of Genetic Diversity with SSR Markers for Cotton Major Cultivars in China

【目的】采用SSR标记构建2008年中国3大棉区8个棉花主产省份32份棉花主栽品种的DNA指纹图谱并进行遗传多样性分析。【方法】从214对候选引物中筛选出36对多态性高、稳定性好且在染色体上分布均匀的引物作为核心引物,构建棉花主栽品种DNA指纹图谱。【结果】36对SSR引物在32份材料中共扩增出142种多态性基因型,每对引物的基因型从2—11种不等,平均每对引物扩增出3.94种基因型。9对引物在10个品种上具有特征带型。最少采用5对引物进行组合鉴定即可将32个棉花品种完全区分开。NTSYS-pc V 2.10软件分析表明,长江流域棉区品种间遗传差异最大,新疆棉区次之,黄河流域棉区最小。常规品种的遗传基础窄于杂交陆地棉。【结论】核心引物组合法相比特征谱带法更适用于构建中国棉花主栽品种DNA指纹图谱,品种间的亲缘关系与地理来源有一定的相关性。

[ 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 toll. 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.