喜马拉雅-横断山区钟花报春居群遗传多样性及遗传分化

Genetic Diversity and Differentiation in Primula sikkimensis (Primulaceae) in Himalayan-Hengduan Mountains

摘要:

应用简单序列重复区间(ISSR, Inter-simple sequence repeat)分子标记,对喜马拉雅-横断山区钟花报春(Primula sikkimensis)进行居群遗传分析。用10个ISSR引物对13个居群的254个个体进行扩增,共检出91条扩增片段,全部为多态带,总的多态位点百分率为100%。Shannon多样性指数(H_O) 从0.2293到0.4016,居群水平上平均值(H_POP)为0.3211,物种水平上(H_SP)为0.5576。利用分子方差(AMOVA) 软件分析,其结果为:在总的遗传变异中,有50.28%的遗传变异属于居群之间;用POPGENE计算出的遗传分化系数G_ST= 0.4127,即居群间的分化变异占居群总遗传变异的41.27%,比AMOVA分析所得的结果偏低。居群间遗传距离变化范围从0.0780到0.4748,遗传一致度(I)的变化范围从0.6220到0.9250。居群间的基因流Nm = 0.7114,相对低的基因流可能是维持钟花报春居群遗传分化的原因。这表明,喜马拉雅-横断山区钟花报春的13个居群具有很高的遗传多样性,并且居群间的分化也很大。

Abstract:

Population genetic structure ofPrimula sikkimensis distributed in Himalayan．Hengduan Mountains was studied using Inter-simple sequence repeat(ISSR)markers．Ten ISSR primers were used to amplify 254 individuals of 13 populations，which successfully detected 91 loci，all of which being polymorphic．The Shannon diversity index(H_O)ranged from O.2293 to O.4016，with an average of 0.321l at the population level(H_POP)and O.5576 at the species level(H_SP )．Moreover，the AMOVA analysis showed that 50.28％ of the total genetic diversity was among populations；the index(G_ST=0.4127) based on POPGENE indicated tIlat 41.27％of molecular variation was among populations． which was lower than that in the result of AMOVA． The variation of genetic distance ranged from 0.0780 to 0.4748，genetic identity from 0.6220 to 0.9250．In addition, the gene flow am ong population was low (Nm=0.7l14)；relatively lower gene flow might be one of important factors influencing the genetic structure of the species．The present analysis reveals that 13 populations of P sikkimensis in Himalayan-Hengduan Mountains have high genetic diversity and high genetic diferentiation.