贵州野生匍匐剪股颖种质资源遗传多样性的ISSR分析

Genetic diversity identification based on ISSR analysis of Agrostis stolonifera germplasm resources in Guizhou

匍匐剪股颖是我国重要的冷季型草坪草之一。为了研究贵州野生匍匐剪股颖居群遗传变异水平、遗传结构及亲缘关系,本试验采用ISSR标记技术对贵州的4个匍匐剪股颖居群共285个个体进行了遗传变异分析。9个引物共扩增出81条带,其中多态性条带66条,无论是在居群水平还是在物种水平,均表明贵州野生匍匐剪股颖居群存在丰富的遗传变异;3个野生居群间遗传分化系数（Gst）为0.492 0,居群间基因流的估测值（Nm）为0.516 4,表明居群间存在较为严重的遗传分化;亚居群间的遗传距离（GD）为0.087 7-0.592 6,遗传距离（GD）的聚类分析结果与居群地理分布存在密切联系。利用SPSS 11.0软件对地理距离与亚居群间遗传距离相关性进行分析,表明地理距离与遗传距离呈显著正相关（r=0.494）;用POPGENE 1.31软件对居群间的遗传关系分析表明,各居群间的遗传一致度比较高,分布为0.700 3-0.940 9,但栽培居群（KROMI）与其他3个野生居群存在明显的遗传差异。

Agrostis stolonifera is a widely grown, cool season turf grass in China. To determine genetic diversity and relationships of A. stolonifera resources, 285 plants from three wild populations and a cultivated population in Guizhou were screened by inter simple sequence repeat（ISSR）markers. Nine of 60 primer pairs produced a total of 81 bands, of which 66 were polymorphic. Statistic analysis showed a rich genetic diversity of A. stolonifera resources in Guizhou province. The genetic differentiation coefficient （Gst） and the gene flow （Nm）among three wild populations were 0. 492 0 and 0. 516 4 . The genetic differentiation was considerable in the three wild populations. The genetic distance GD）of the subpopulations ranged from 0. 087 7 to 0. 592 6. The subpopulations could be clustered into three groups based on GD. Correlation analysis found a significant positive correlation between geographical distance and genetic distance （r=0. 494）, and this is persuasive evidence that there is a significant correlation between genetic component and the geographic distribution of A. stolonifera resources. Further genetic relationship analysis discovered a high genetic similarity among wildpopulations, ranged from 0. 700 3 to 0. 940 9 while the cultivated population （KROMI） had an obvious genetic differentiation from wild populations.