基于ISSR标记的16个核桃品种遗传多样性分析及分子身份构建

Analysis of Genetic Diversity and Establishment of Molecular ID for 16 Walnut Varieties Based on ISSR Markers

为了分析16个核桃栽培品种的遗传关系和构建分子身份证,以核桃幼叶为材料提取其基因组DNA,利用ISSR分子标记方法,从28条引物中筛选出10条引物对16个核桃栽培品种进行标记分析。结果表明,10条ISSR引物共扩增出115个位点,每条引物可获得9-15条DNA片段,平均为11.5条,其中多样性位点99个,多态性百分比达86.09%,16个核桃品种之间的平均有效等位基因数（Ne）为1.5080,Nei＇s基因多样性指数（H）为0.3041,Shannon信息指数（I）为0.4577,遗传相似系数（GS）变幅为0.42-0.82。采用UPGMA方法构建的聚类图表明,16个核桃品种可以划分为4个组,品种间遗传信息差异比较大,具有丰富的遗传多样性,能够通过ISSR标记方法将16个品种区分开。此外从10条引物中筛选出3条引物作为16份核桃品种资源种质鉴定的核心引物,构建了每个核桃品种的分子身份证。本研究通过构建16个核桃品种的分子身份,为核桃品种鉴定和品种权保护提供了依据,也为核桃育种亲本的选配和种质资源鉴定奠定了基础。

In order to analyze the genetic diversity and relationships among 16 walnut（ Juglans regia L.） varieties and to establish their molecular identities,10 ISSR primers were screened from 28 primers to amplify the walnut genomic DNA.The results showed that 115 loci were detected and 99 loci were polymorphic,with a polymorphic ratio of 86. 09%.Effective number of alleles（ Ne）,Nei＇s gene diversity（ He） and Shannon＇s Information index（ I） of 16 samples were1. 5080,0. 3041 and 0. 4577,respectively. The genetic similarity coefficient for 16 walnut varieties ranged from 0. 42 to0. 82. Unweighed averages（ UPGMA） cluster analysis was used to construct a dendrogram and 16 walnut varieties were divided into four groups. The cluster analysis indicated that all the 16 varieties could be distinguished by ISSR markers and the difference of genetic information among 16 walnut varieties was significant,indicating that there existed higher genetic diversity among them. Three of 10 primers were further determined as the core primers for germplasm identification and molecular ID establishment of walnut varieties. In the present study,the molecular identities of 16 walnut varieties were established,which provided a good foundation for variety identification and protection of walnut,it is valuable for the germplasm identification and parent selection of walnut hybridization breeding in the future.