苹果EST-SSR引物的开发及部分品种亲缘关系分析

Development of apple EST-SSR primers and phylogenetic analysis of some cultivars

【目的】开发苹果EST-SSR引物,评价苹果种质资源的多样性与亲缘关系。【方法】利用NCBI数据库中苹果EST的SSR位点开发了35对EST-SSR引物,建立了苹果EST-SSR体系,并利用筛选出的16对引物对苹果品种资源的亲缘关系进行研究。【结果】118份基因组DNA共扩增出等位基因位点138个,位点数的变化从3到13不等,平均每对引物检测到8.62个位点,总的多态性比率为94.2%,各引物的多态性比例分布为81.8%～100%,相似系数为0.48～1.00。利用UPGMA法构建聚类树状图,在相似性系数0.65处可将118个供试材料分为5大组:其中第1组又可分为2个亚组,包含了绝大部分供试材料;第2、3、4和5组包含的品种数目分别为12个、11个、3个和2个;第5组与其他组亲缘关系较远,相似性系数仅为0.48。【结论】筛选出的16对EST-SSR引物可用于评价苹果种质资源间的遗传多样性。

[Objective]The aims of this study were to develop EST-SSR primers which were used to evalu- ate the genetic diversity and genetic relationships of apple germplasm resources. [Method]Thirty five pairs of EST-SSR primers were developed by using SSR locus located in Malus EST from NCBI database, and Ma/us EST-SSR system was constructed in this study. Sixteen pairs of primers were selected to investigate genetic relationships of 118 apple resources. [Results] Sixteen pairs of primers were selected by Polyacry- lamide gel electrophoresis （T=8%） according to the standard of polymorphism and stability. The sixteen pairs of primers amplified 138 alleles, with an average of 8.62 alleles per locus. The polymorphism per- centage of amplified loci was 81.8% to 100%, and the average polymorphism rate was 94.2%. Based on the SSR results, the similarity coefficient of the 118 cultivars distributed in the range of 0.48 to 1.00. Ac- cording to the constructed UPGMA cluster, the 118 cuhivars could be classified into five groups at 0.65. Group I contains most of the 118 cultivars, Group I1 , m, rv, v contain 12, 11, 3 and 2 cultivars re- spectively. Group V has a distant relationship with the other groups. [Conclusion]The selected EST-SSR primers developed from apple EST database would be suitable for evaluating the genetic relationship of apple germplasm resources.