基于ISSR分子标记的紫云英种质资源遗传多样性及结构分析

紫云英(Astragalus sinicus L.)是我国重要的稻田绿肥作物，为揭示不同地区种质资源遗传特征，本研究利用ISSR分子标记对77份紫云英种质资源进行了遗传多样性及结构分析。研究发现，77份供试紫云英种质资源遗传相似性系数为0.567 7～0.868 6,可划分为6个聚类。不同地区群体间分化系数为0.136 3,达到极显著水平(P<0.001),其中种群间变异占比13.9%,种群内变异占比86.1%。不同ISSR引物扩增信息鉴别紫云英资源的能力存在差异，构建了以P809第3,8,9,10,12,15扩增位点以及P886第1,3,5,9,10,11扩增位点为特征的指纹图谱，能有效区分77份供试紫云英资源。以资源所在省份为单元进行群体分析，供试紫云英资源遗传结构呈现分化特征，河南-安徽-江苏-上海资源遗传结构相似，构成北方亚群；四川-广西-湖南-江西资源相似，构成西南方亚群；福建种质资源则呈现混合型特征。本研究结果可为我国紫云英种质资源的科学利用及新品种选育提供依据。

Genetic Diversity and Structure Analysis of Germplasm Resources Based on ISSR Markers in Astragalus sinicus L.

Astragalus sinicus L. is one of the most important green manure crops in China. In this study,the genetic diversity and structure of 77 A. sinicus germplasm lines were investigated based on ISSR molecular markers. The results showed that the genetic similarity coefficients of the 77 lines ranged from 0.567 7 to 0.868 6,which had been divided into 6 clusters. The population differentiation score (PhiPT) across the regions was 0.1363,at a significant level (P<0.001),among which the inter-population and intra-population variations accounted for 13.9% and 86.1% respectively. The primer pairs showed various abilities to identify these 77 lines,and ISSR fingerprinting was constructed based on amplification bands 3,8,9,10,12,and 15 by primer pairs of P809 and amplification bands 1,3,5,9,10,and 11 by primer pairs of P886,which could effectively distinguish all the 77 lines. It was discovered that the genetic structure of A. sinicus L. exhibited two subpopulations,one located in the northern regions including Henan,Anhui,Jiangsu and Shanghai with similar genetic structure,and the other in the southwest including Sichuan,Guangxi,Hunan and Jiangxi. The lines in Fujian were with mixed genetic background. It provided a basis for the utilization of resources of A. sinicus L in genetic studies and breeding.