利用EST-SSR技术分析银合欢种质资源遗传多样性

银合欢（Leucaena spp.）是豆科含羞草亚科银合欢属多年生木本植物，为了了解其种质资源的遗传多样性，采用184对引物对银合欢种质进行扩增，选择多态性较好的20对引物对48份银合欢种质进行遗传多样性分析。结果表明：184对引物中有119对为有效引物，占总引物数的64.67%，其中具有多态性的有效引物55对，占有效引物数的46.22%，占总引物数的29.89%；使用多态性较好的20对引物对48份银合欢种质进行遗传多样性分析，其相似系数为0.618 2~0.941 2，平均多态性信息指数和Shannon信息指数分别为0.266和0.536。通过聚类分析将48份种质在相似系数0.78处分为5个类群，全部异叶银合欢（Leucaena diversifolia）种质聚在了类群I并与银合欢种质分开；单独聚类在类群II的c27号种质与其他银合欢种质差异较大，是较好的种内杂交育种的种质；类群V中不同来源地的银合欢各种质聚在一起，可能与银合欢自交不育和育种方式有关。

Analysis of Genetic Diversity in Leucaena Germplasm Using Stylosanthes EST-SSRs

In order to analyze the genetic diversity of 48 Leucaena germplasm resources, 20 more polymorphic effective markers were screened from 184 Stylosanthes EST-SSR markers. The result showed that 119 of 184 Styloanthes EST-SSR markers were effective markers and 55 markers were polymorphic, the effective and polymorphic transferable rate was 64.67% and 29.89%, respectively. Furthermore, in the genetic diversity analysis and cluster analysis of 48 Leucaena germplasm resources, the range of GS is 0.618 2~0.941 2, and the average of PIC and Shannon index are 0.266 and 0.536, respectively. All accessions were divided into 5 major group(I,II,III,IV and V). All of the Leucaena diversifolia germplasm were clustered in Group I, and Leucaena leucaephala accessions from different sites were divided into Group V. Accession c27 clustered separately in Group II is a good material for crossbreeding in Leucaena. In summary, the Stylosanthes EST-SSR markers can be utilized in analysis of genetic diversity, mining and identification of gene and breeding in Leucaena. Due to the complex genetic relationships, analysis of genetic relationships of Leucaena germplasm should be researched generally with several tools.