利用SSR标记分析小豆种质资源的遗传多样性

 【目的】分析小豆起源国中国丰富的小豆种质资源的遗传多样性及群体结构,提高这些种质在育种中的利用效率。【方法】选用51对SSR引物对国内外145份小豆种质进行多样性评价,并分析了中国小豆种质资源间的遗传关系和遗传结构。【结果】共检测出222个等位变异,每SSR位点的等位变异数为2～13不等,平均为4.35个,其中分布频率低于5%的等位变异数占35.9%。多态性信息含量（PIC值）为0.014～0.838,平均为0.472。不同种质间遗传相似性系数为0.227～0.951,平均为0.482。比较分析发现,湖北、陕西等省小豆资源的遗传变异最丰富,且遗传背景与中国主产区小豆存在较大差异。基于NTSYS的聚类可以将145份小豆种质划分为5组,根据组内种质的地理来源,可分别命名为东北组、华北Ⅰ组、华北Ⅱ组、华东组和混合组,其中混合组主要由湖北、陕西及国外种质组成。利用STRUCTURE对小豆种质资源的遗传结构分析与NTSYS聚类结果基本一致,即种质的遗传背景与地理来源有关。【结论】中国小豆种质资源遗传变异丰富,不同地理来源小豆间存在遗传分化,可以作为小豆生态区划的重要参考依据。

Genetic Diversity Among Adzuki Bean Germplasm Revealed by SSR Markers

【Objective】 Adzuki bean originated from China, and there are abundant germplasm in China. Evaluation of the genetic diversity can accelerate the application of them in breeding program. 【Method】 In this study, 51 pairs of SSR primers were used to assess the genetic diversity and structure among 137 Chinese and eight alien adzuki bean germplasm. 【Results】 A total of 222 alleles were detected and the alleles with frequency lower than 5% accounted for about 35.9%. The number of alleles changed from 2 to 13 with an average of 4.35 per locus. The PIC value varied from 0.014 to 0.838, and the mean PIC value for SSRs on each linkage group was 0.440. The similarity coefficient between accessions varied from 0.227 to 0.951 and averaged at 0.487. Adzuki bean from Hubei and Shaanxi provinces had much higher genetic variations, and their genetic backgrounds are much different from that of other provinces. Cluster analysis divided the 145 accessions into five groups, which is much agreeable with that obtained in analysis by using STRUCTURE package, and the accessions within five groups almost related with their origins of geographical distribution. 【Conclusion】 There are abundant genetic variations in Chinese adzuki bean. The genetic differentiation among adzuki bean from different origins is important in dividing ecological region for Chinese adzuki bean.