基于表型性状和SSR标记的板栗品种遗传多样性分析及分子身份证构建

Genetic Diversity Analysis and Fingerprinting of Chestnut Varieties Based on Phenotypic Traits and SSR Markers

本研究以55个板栗品种为材料,对这些板栗品种的单粒重量、横径长度和纵径长度等14个表型性状进行测定及分析,部分板栗品种形态性状指标差异不显著,仅利用表型性状很难进行准确的品种鉴定。因此本研究基于板栗全基因组序列开发SSR标记,并对55个板栗种质资源进行PCR扩增,利用POPGENE32、PowerMarker V3.25和NTSYS Version 2.10软件对SSR标记数据进行分析,筛选出6对多态性较好的SSR引物。6对引物共检测到31个等位基因,多态位点百分率达100%,多态性信息含量指数、Nei′s基因多样性指数、Shannon′s多态性信息指数、观测杂合度和期望杂合度的平均值分别为0.651、0.696、1.358、0.524、0.703。利用筛选出的6对引物能够明确区分供试的55份板栗品种,并构建了55个板栗品种的字符串、条形码和二维码分子身份证。本研究利用表型性状和SSR标记研究板栗品种的遗传多样性,构建板栗品种的分子身份证,为板栗种质资源的品种鉴定、合理利用和有效保护提供理论参考。

In this study,14 phenotypic traits including single grain weight,cross-diameter length and longitudinal diameter length of 55 chestnut cultivars were measured.However,no significant differences on morphological traits in subsets of chestnut varieties were observed,and it is difficult to identify the varieties accurately using phenotypic traits.We designed SSR markers based on chestnut genome,followed by PCR amplification of 55 chestnut species and data analysis using the software POPGENE32,PowerMarker V3.25 and NTSYS V2.10.By taking use of six pairs of SSR primers with good polymorphisms,31 alleles were detected and the percentage of polymorphic loci was 100%.The mean values of polymorphism information content index,Nei′s gene diversity index,Shannon′s polymorphism information index,observed heterozygosity and expected heterozygosity were 0.651,0.696,1.358,0.524 and 0.703,respectively.According to the SSR-based genotyping results,55 chestnut cultivars were classified enabling the construction of their fingerprints.Collectively,this study deployed the phenotypic datasets and SSR markers to decipher the genetic diversity of chestnut varieties and generate the molecular ID cards,which provided theoretical references for the variety identification,rational utilization and effective protection of chestnut germplasm resources.