云南干热河谷地区余甘子居群的遗传多样性研究

余甘子(Phyllanthus emblica)是我国西南干热河谷地带的优势植物, 也是一种重要的药用经济植物, 对其遗传多样性进行研究对生态环境的建设和恢复有着重要意义。作者采用ISSR分子标记技术对分布于云南干热河谷地区的4个余甘子居群的遗传多样性水平进行了检测。12条引物共扩增出135条清晰、重复性好的DNA条带, 其中多态性条带为115条, 多态位点百分率(PPB)为85.19%。居群间的遗传分化系数(G_ST)为0.1222, 基因流(N_m)为1.7958。结果表明余甘子居群具有较高的遗传多样性水平, 而居群间存在较低的遗传分化, 这可能主要是由其繁育特性造成的。Mantel 检测表明地理距离和Nei’s遗传距离间无相关性(r = 0.19798, P = 0.6513 > 0.05)。当我们进行干热河谷地区生态恢复时，以上结果对于确定余甘子的取样策略具有指导意义。

Genetic diversity of Phyllanthus emblica populations in dry-hot valleys in Yunnan

Phyllanthus emblica(Euphorbiaceae)is one of the dominant species distributed in dry-hot valleys of southwestern China.Besides its function in ecology,environment and reforestation,it is also an important medicinal plant.We studied the genetic diversity in four populations of P.emblica sampled from dry-hot valleys of Yunnan using ISSR(inter-simple sequence repeats)markers.Based on 12 primers,135 clear and reproducible DNA fragments were generated,of which 115 were polymorphic,accounting for 85.19%.The coefficient of genetic differentiation(GST)equaled 0.1222.Such a high level of genetic diversity and low level of population genetic differentiation might result from the breeding system of this species.There was a lack of significant association between genetic and geographical distances(r=0.19798,P=0.6513>0.05)among P.emblica populations.The results suggest some important recommendations about sampling meth-ods to be used in ecological reforestation of dry-hot river valleys.