基于SSR分子标记的延胡索遗传多样性研究

采用SSR分子标记分析延胡索的遗传多样性,筛选出多态性高、稳定性好的12对引物,对19个居群360份延胡索样品进行了群体遗传分析。结果表明:(1)12对SSR引物共扩增出多态性位点227个,检测到4~9个等位基因,平均等位基因数目为5.25个,表现出丰富的多态性;延胡索居群具有较高的遗传多样性(Na=5.25,I=1.192 6,H=0.387 9),物种间遗传分化程度高(Fst=0.388 3),基因流较弱(Nm=0.393 8)。(2)UPGMA聚类分析和贝叶斯距离分析结果表明,19个居群明显聚为4大支;Mantle Test结果(r=0.326,P=0.01)表明,地理位置相近的种群亲缘关系更近。研究认为,延胡索的遗传结构是该物种自交为主的繁育系统、克隆生长、地理隔离以及居群间有限的基因流共同作用的结果,故对该物种的保护应以就地保护为主。

Genetic Diversity of Corydalis yanhusuo W. T. Wang Based on SSR Molecular Markers

In this study, genetic diversity of Corydalis yanhusuo W.T.Wang was analyzed with SSR molecular markers, twelve pairs of primers with high polymorphism and good stability were screened for population genetic analysis for 360 individuals sampled from 19 populations. The results showed that: (1) a total of 227 polymorphic loci were amplified from 12 pairs of SSR primers, 4-9 alleles were detected and average of 5.25 per primer, which showed the primer pairs were of abundant polymorphism and could be used to analyze the genetic diversity of C. yanhusuo. The study revealed that the genetic diversity among the population groups was high (N_a = 5.25, I = 1.192 6, H = 0.387 9), the degree of genetic differentiation was high (F_st = 0.388 3), and the gene flow among species was limited (N_m = 0.393 8). (2) The results of cluster analysis used by both UPGMA and Bayes method showed that 19 populations obviously clustered into 4 branches. The result of Mantle test (r = 0.326, P = 0.01) indicated the population with shorter geographical distance performed tighter genetic relationship. The genetic structure of C. yanhusuo may be resulted from its predominantly selfing breeding system, clonal growth, geographic isolation and limited gene flow. In situ conservation should be accepted in its protection considering its genetic structure.