利用RAPD分子标记研究苜蓿种质资源遗传多样性

Study on the genetic diversity of Medicago sativa using RAPD/PCR

利用RAPD分子标记对53份苜蓿Medicago sativa种质资源的遗传多样性进行分析,计算了35个RAPD分子标记的多态性比率和每份苜蓿种质资源的Shannon多样性指数和Nei指数,并通过计算53份苜蓿种质资源的遗传距离(CD),进行聚类分析,探讨它们之间的亲缘关系。结果如下:1)35个RAPD标记扩增共得到306条带,其中多态性条带288条,多态位点比率为94.12%。说明这53份苜蓿种质资源具有较高遗传多样性。2)53份苜蓿种质资源的Shannon多样性指数和Nei指数变化规律一致。直立黄花苜蓿的Shannon多样性指数和Nei指数最低,说明其遗传多样性最小;公农1号的Shannon多样性指数和Nei指数最高,说明其遗传多样性最大。3)53份苜蓿种质资源间的遗传距离变异范围为0.136 3～0.661 0。以λCD=0.275为标准将53份苜蓿种质资源划分为7个组群,直立黄花苜蓿单独被划分成一个组群。

Results of the study on genetic diversity of 53 varieties of Medicago sativa showed that, 1） 35 primers were selected for analysis and yielded a total of 306 loci, 288（94.12%）of which were polymorphic. 2）By Shannon＇s index and Nei＇s index, the genetic diversity of M. falcate cv. Zhili was the lowest, and that of M. sativa cv. Gongnong No. 1 was the highest. It can be seen that the results by the Nei index are almost as same as that by Shannon index. 3） Genetic distance of M. sativa was calculated by Nei method and the results were： the genetic distance was ranging from 0. 136 3 to 0. 661 0. The shape of the RAPD dendrogram suggested that 53 varieties of M. sativa should be divided into seven groups by λCD=0. 275.