冬虫夏草(Cordyceps sinensis)的随机扩增多态DNA及其遗传分化

Genetic Divergence of Cordyceps sinensis as Estimated by Random Amplified Polymorphic DNA Analysis

本文对来自青藏高原3个区域5个具有代表性地方的13个冬虫夏草(Cordyceps sinensis[Berk.] Sacc.)样本进行随机扩增多态DNA(RAPD)分析。19个随机引物获得的RAPD谱带清晰并呈现多态,单个引物获得的RAPD片段数在3～10个之间。该19个引物在每个样本中扩增的RAPD片段总数平均约为65个。基于遗传距离分析,受试的13个冬虫夏草样本中,来自同一地方的样本间遗传差异甚微,同一区域不同地方的样本间遗传差异较大,不同区域的样本间遗传差异最大。这说明冬虫夏草地理群体间存在着遗传分化。应用UPGMA和NJ方法构建的分子系统树显示,来自5个地方的冬虫夏草实际上可以归并为显著不同的3个组,对应于样本来源的3个区域,提示RAPD标记在冬虫夏草群体中有显著的地区特异性。我们的结果还表明,冬虫夏草地理群体间的遗传差异度与地理距离呈正相关。因此,RAPD作为有效的遗传标记,可用于研究冬虫夏草的遗传多样性、起源以及系统演化等。

Random amplified polymorphic DNA(RAPD) has been used in analyzing 13 winterworm, summer grasses (Cordyceps sinensis [Berk.]. Sacc.) from 5 areas in Qingzangplateau. For 19 arbitrary primers, each individual showed about 65 RAPD markers.The genetic distances among those 13 winter worm, summer grasses were correlated totheir geographic distances. Molecular phylogenetic tree constructed by UPGMA and NJsuggested that 13 winter worm, summer grasses could be divided into 3 clusters: eastcluster, north cluster and middle cluster, in consistence with their origins and geneticdivergence among different clusters. Furthermore, our results implied that the RAPDmarkers of winter worm, summer grasses showed a geographic specificity and couldbe a better genetic marker in studying genetic diversity and phylogeny of winter worm,summer grasses.