利用SSR标记分析黄瓜种质资源的遗传多样性

SSR Analysis of Genetic Diversity of Cucumber Germplasm

利用SSR标记对国内外102份黄瓜种质资源进行了遗传多样性分析.从48个SSR标记中筛选出17个多态性标记,共检测到42个等位基因,其中10个为稀有等位基因,各标记PIC值介于0.019～0.384之间.在4个不同生态类群中,华南型含等位基因数最多,日本东南亚型次之,其它类型均最低;多态性位点比例以华南型和日本东南亚型最高,华北型最低;华南型遗传多样性指数较其它类型均高.聚类分析表明,102份种质资源的相似性系数在0.42～1.00之间.在相似性系数0.65处,102份种质资源被分成3大类,基本上按刺瘤特征被区分.主成分分析表明,华北型和欧洲型分布比较集中,其它生态型分布则较为宽广;密刺型和无刺型各自分布在一定区域,而刺瘤中等与稀少的中间类型处于2者之间.

Simple sequence repeat markers were utilized to characterize the genetic diversi- ty of 102 cucumber accessions originating from China and other countries. A total of 48 SSR markers were analyzed and 17 of them were polymorphic. The 17 SSR markers revealed a total of 42 alleles, 10 of them were rare alleles. The Polymorphic information content （PIC） values of the markers varied from 0. 019 to 0. 384. Among four different ecological populations, the total number of alleles was highest in Southern China population, while medium in South-east Asia population and lowest in other three populations. The proportion of polymorphic loci is highest in Southern China population and South-east Asia population, while lowest in Northern China population. The genetic diversity index value is highest in Southern China population. The similarity coefficients in the 102 cucumber accessions range from 0.42 to 1.00. Three main groups, mainly according to the density of fruit wart or spine, can be distinguished by truncating the dendrogram at GS value of 0.65. PCA analysis showed that the Northern China population and European greenhouse population concentrated whereas other populations distributed dispersedly. Dense and none fruit wart or spine cucumbers concentrated in a respective region and was separated from other types, whereas the intermedium and sparse fruit wart or spine cucumber distributed between them.