豇豆种质资源SSR标记遗传多样性分析

从46对备选的豇豆SSR引物中鉴定筛选出扩增带单一、稳定清晰且多态性强的13对引物。用这13对引物，对来自中国、非洲和亚洲其他国家的共316份栽培豇豆[Vigna unguiculata (Linn) Walp.]资源的DNA进行SSR扩增，以研究其遗传多样性。结果共检测到47个等位位点，平均每对引物扩增出3.692个等位位点，有效等位基因平均2.003个；5对SSR引物VM16、VM26、VM20、VM25和VM23，对于检测豇豆遗传变异最为有效。UPGMA聚类图显示，13对SSR引物即能将其中的260份参试资源区分开，其中国内、外资源差异明显，被划为2大类群；国内资源类群又可分为与地理来源的气候生态区明显关联的2个北方组群、4个南方组群和2个混合组群，8个组群间相对独立又相互渗透；国内育种高代材料的遗传多样性狭窄。

Genetic Diversity Analysis of Cowpea Germplasm Resources by SSR

Thirteen reproducible and informative SSR primer pairs were selected from the 46 candidates. A representative set of 316 cowpea genetic resources from China, Africa and other countries of Asia, were analyzed by SSR methodology using these informative primer pairs. A total of 47 alleles were detected with an average of 3.692 alleles per SSR primer pair, and on an average 2.003 alleles from each SSR primer pair were effective. According to integrated evaluation, five SSR orimer pairs, VM16, VM26, VM20, VM25, and VM23, were most effective for genetic diversity studies of cowpea. The dendrogram by UPGMA cluster analysis showed that 260 accessions of the 316 were distinct and revealed enough genetic diversity for identification and classification of accessions within Vigna unguiculata. There was a clear difference between foreign and Chinese genetic resources. Within Chinese accessions, 8 distinct groups including two northern groups, four southern groups and two complex groups, were detected, indicating that the Chinese breeding lines have a narrow genetic background.