基于表型性状和SSR分子标记构建甜荞初级核心种质

Construction of Primary Core Collection of Buckwheat Germplasm Resources Based on Phenotypic Traits and SSR

利用SSR分子标记技术研究甜荞种质资源的群体结构,构建甜荞的核心种质库,为甜荞种质资源的科学管理、高效利用和有效保护提供理论依据。本研究利用各个材料的来源地信息和5个表型性状以及7对SSR标记,对1287份甜荞种质资源的遗传多样性进行了评价。采用Powermaker等软件计算有效等位基因数(Na)、Shannon′s信息多样性指数(I)、Nei′s遗传多样性指数(H),对构建的初级核心库进行遗传分析。表型性状分析结果表明,5个表型性状在不同的甜荞种质资源中表现出较大的差异,变异系数的变化范围在17.13%~33.87%之间,平均为24.64%,其中茎直径变异系数最大,是造成表型变异的主要因素。表型聚类将所有材料划分为5个亚群,大部分材料集中在第5亚群,其余材料则表现出一定的区域性特征。SSR标记分析表明,1287份材料的Nei多样性指数为0.32~0.50,平均值为0.43。基于SSR分子标记的聚类分析表明,种质资源与其地理分布存在一定的相关性。表型性状和SSR分子标记结果均表明甜荞种质资源具有丰富的遗传多样性,最终构建530份甜荞初级核心种质。

SSR markers were employed for an analysis of population structure of a collection of germplasm resources of common buckwheat,and a core collection of the germplasm resources was constructed in order to provide a theoretical basis for scientific management,efficient utilization and effective protection of germplasm resources of the species.In this study,the genetic diversity of 1287 common buckwheat germplasm resources was evaluated by using the geographical information,5 phenotypic traits and 7 pairs of SSR markers.Genetic diversity parameters such as effective number of alleles(Na),Shannon′s information index(I),Nei′s diversity index(H)were calculated by Powermaker and other software.The analysis of five phenotypic traits revealed great variation in different germplasm resources.The coefficient of variation ranged from 17.13%to 33.87%,with an average of 24.64%.The coefficient of variation of stem diameter was the largest,which was the main factor causing phenotypic variation.The 1287 accessions were divided into five groups,most of which were clustered in the fifth subgroup,and the others showed regional specificity.The analysis of SSR indicated the index of similarity coefficient ranged from 0.32 to 0.50 with an average of 0.43.Clustering analysis based on SSR molecular markers showed that there was a certain correlation between germplasm resources and their geographical distribution.The results of phenotypic traits and SSR molecular markers showed that there was abundant genetic diversity in common buckwheat germplasm resources and 530 accessions of primary core collection were constructed.