基于SSR标记的党参属部分药用植物的遗传多样性和遗传结构评价

Evaluation of Genetic Diversity and Structure of Some Medicinal Plants of Codonopsis Based on SSR Markers

目的:采用简单重复序列(SSR)标记技术对来自中国6个省市的党参属4种药用植物进行分析,为党参核心种质资源构建和分子标记辅助育种积累资料。方法:利用10对SSR分子标记引物对党参的遗传多样性和分化程度进行分析,并对党参属的3种药用植物(党参、素花党参、川党参)居群进行聚类分析和遗传结构评价。结果:党参10对SSR引物各位点平均等位基因数(Na)和多态性位点百分率(PPL)分别为4. 1和100%;观察杂合度(Ho),期望杂合度(He),平均杂合度(Ha),Shannon’s信息指数(I)的平均值分别为0. 431 9,0. 486 2,0. 410 3,0. 853 7。党参居群水平上的Na,I,He和Ho分别为1. 9~3. 2,0. 44~0. 90,0. 28~0. 57和0. 27~0. 61;其中甘肃陇西德兴家种居群遗传多样性最丰富。遗传相似度的聚类分析将供试党参、素花党参、川党参和秦岭党参共38个居群划分为3类,秦岭党参居群单独为一类(类群Ⅰ),川党参居群和素花党参居群为第二类(类群Ⅱ),党参居群为第三类(类群Ⅲ)。党参、素花党参、川党参的遗传结构分析分为2个基因池,过渡类型少。结论:党参具有丰富的遗传多样性,这一特性与其迁地引种的历史以及自身生物学特性相关;党参居群间存在较高程度的遗传分化,这可能源于自然地理隔离以及近期人类活动引起的生态环境片段化。本文为党参遗传多样性、遗传结构和资源保护等方面的研究提供了理论依据。

Objective:In order to provide beneficial reference for the construction of core germplasm resources and molecular marker for assisted breeding of Codonopsis Radix,four Codonopsis taxa from 6provinces and cities in China were analyzed by simple sequence repeat (SSR)markers.Method:Ten pairs of SSR markers were applied to the investigation of genetic diversity and differentiation degree of Codonopsis Radix,then thephylogenetic relationship and genetic structure of three Codonopsis taxa (C.pilosula,C.pilosula var.modesta and C.tangshen)were evaluated.Result:The average allele number (Na)and percentage of polymorphic loci (PPL)were 4.1and 100% in all points of ten pairs of SSR primers of Codonopsis Radix;their average values of observed heterozygosity (Ho),expected heterozygosity (He),average heterozygosity (Ha)and Shannon's information index (I)were 0.4319,0.4862,0.4103,0.8537,respectively.Na,I,He and Ho at the levels of Codonopsis Radix population were 1.9-3.2,0.44-0.90,0.28-0.57and 0.27-0.61,respectively.The genetic diversity of cultivate population from Dexing country of Gansu province was the most abundant.The phylogenic tree was constructed based on Nei's genetic distance and 38populations were divided into 3 clusters, C.tsinlingensis were separated to cluster I ,cluster Ⅱ were divided into 2groups (C.pilosula vat.modesta and C.tangshen),while C.pilosula belonged to cluster Ⅲ.Then genetic structure analysis of C.pilosula, C.pilosula var.modesta and C.tangshen was divided into two gene pools with few transition species.Conclusion: The resource of Codonopsis Radix is abundant in genetic diversity.This characteristic is related to the history of the introduction of the species and its own biological characteristics.There is a higher degree of genetic differentiation among the populations of Codonopsis Radix,which may result from the isolation of natural geography and the fragmentation environments caused by current human activities.These results provide a theory basis for the study on genetic diversity,genetic structure and resource protection of Codonopsis Radix.