基于SSR标记的青藏高原野生大颖草遗传多样性分析

Analysis of the Genetic Diversity of Wild Kengyilia grandiglumis on the Qinghai-Tibet Plateau Based on SSR Markers

大颖草是分布在青藏高原且适应沙生和高寒环境的一种多年生禾草,对其进行遗传多样性评估是种质资源利用的前提,但目前其在居群水平的遗传多样性仍不清楚。本研究应用SSR标记对4个代表性生境下大颖草居群的55份材料进行了遗传多样性分析。结果表明,4个居群的平均等位基因数、有效等位基因数、香农信息指数和遗传多样性指数分别为1.3750、1.1685、0.1624和0.1042,指示大颖草遗传多样性偏低。4个居群之间的遗传多样性存在差异,其中,GN居群最高,YS居群最低。有70.21%的遗传变异存在于居群内不同个体间,说明居群内变异可以作为遗传多样性主要来源。群体基因流为1.1783,说明居群间存在一定的基因流能有效抑制种群间的遗传分化。UPGMA和群体遗传结构分析结果显示,55份大颖草材料被划分为7个亚群,并与其地理分布具有一定的相关性。本研究初步获得了大颖草居群水平遗传多样性信息,为今后大颖草种质资源的保护及利用提供参考。

Kengyilia grandiglumis is a perennial gramineous grass widely distributed Qinghai-Tibet Plateau adapting to sandy and alpine environments.Application of germplasm resource relies on assessment of genetic diversity,which is still unclear for K.grandiglumis on population scale.In this research,55 accessions of K.grandiglumis from four representative habitats were analyzed for genetic diversity by SSR markers.Results revealed the number of alleles,the effective number of alleles,the Shannon's information index and the genetic diversity index of four populations were 1.3750,1.1685,0.1624 and 0.1042,respectively,indicating relatively low diversity of K.grandiglumis.Diversity differences were found within four populations,in which GN had the highest and YS had the lowest genetic diversity.70.21%of genetic mutations were found among different individuals in the same population,illustrating the majority of genetic diversity was from mutations within populations.A 1.1783 gene flow of population indicated the inhibition of genetic differentiation for populations by certain gene flow.UPGMA and Bayesian cluster analysis demonstrated 55 accessions of K.grandiglumis were clustered to seven subgroups,which correlated with geographic distribution.General information of K.grandiglumis genetic diversity on population scale was obtained and can be applied to further research on conservation and utilization of K.grandiglumis germplasm resource.