基于SSR标记分析四川省桑树种质资源的群体结构和遗传多样性

Population Structure and Genetic Diversity of Mulberry Germplasm Resources in Sichuan Province Analyzed by SSR Marker

利用14对SSR引物对四川省89份桑树种质资源的基因组DNA进行PCR,分析种质资源间的群体结构和遗传多样性。共扩增出迁移率不同的条带65条,多态性条带65条,多态性条带比率达100%;Structure群体结构分析将89份桑树种质资源划分为4个群体,4个群体的多态性信息含量在0.552 0~0.599 8之间,总体为0.657 7;基因多样度在0.554 8~0.600 3之间,总体为0.579 0;等位基因数目在66~76个之间,总体为134个;等位基因丰富度在3.327 2~3.549 1之间,总体为3.983 1;遗传多样性主要来源于品种内,属中等偏高水平;14对SSR引物位点的总基因多样度Ht在0.291~0.931之间,整体为0.699;Nei’s种群内基因多样度Hs为0.287~0.910,整体为0.662;种群间基因多样度为0.003~0.098,整体为0.037;种群间基因分化系数为0.008~0.047,整体为0.053;基因流为2.901~62.000,整体为8.934,遗传变异主要发生在群体内,群体间分化程度低,基因流大。UPGMA聚类分析与群体结构分析结果大致相同,2种分析结果都显示分群无地理迁移规律。

By using simple sequence repeat(SSR) molecular markers to amplify the genomic DNAs of 89 mulberry germplasm resources in Sichuan Province, the population structure and genetic diversity of these tested mulberry germplasm resources were analyzed. The result showed that amplification by 14 pairs of SSR primers yielded 65 bands, which showed polymorphism with a polymorphic percentage of 100%. Using software Structure, 89 mulberry germplasm resources were divided into 4 groups. The polymorphism information contents(PIC) of 4 groups were between 0.552 0 and 0.599 8, and the overall was 0.657 7. The gene diversity was between 0.554 8 and 0.600 3, 0.579 0 overall. The number of alleles was between 66 and 76, totally 134. The allelic richness of alleles was between 3.327 2 and 3.549 1, 3.983 1 overall. The genetic diversity was mainly from inter-varieties with a moderately high level. The total genetic diversity Ht of 14 SSR primer loci ranged from 0.291 to 0.931, 0.699 overall. The genetic diversity Hs in Nei’s population was between 0.287 and 0.911, 0.662 overall. The genetic diversity among populations was from 0.003 to 0.098, 0.037 overall. The degree of gene differentiation among populations was from 0.008 to 0.047, 0.053 overall. The gene flow was from 2.901 to 62.000, 8.914 overall. The genetic variation mainly occurred within populations, while the degree of differentiation among groups was very low, and the gene flow was high. The results of UPGMA cluster analysis and population structure analysis are roughly the same, both of which show that there is no geographical migration rule.