毛乌素沙地微生境梯度中臭柏种群的遗传多样性

GENETIC DIVERSITY OF SABINA VULGARIS UNDER DIFFERENT MICROHABITATS IN MAOWUSU SANDY LAND

应用随机扩增多态性DNA（Random Amplified Polymorphic DNA,RAPD）标记方法对毛乌素沙地图克境内的4类连续变化的微生境中臭柏种群进行了分子生态学测定.用16个随机引物扩增出174条清晰谱带,其中167条为多态性谱带.利用POPGENE3.2 Version1.31软件对数据进行处理,结果如下：（1）4类微生境中臭柏种群有着较丰富的遗传多样性,各微生境中臭柏的多态位点百分率在77.59%～89.08%之间,以A类微生境（乌柳灌丛地）的最高为89.08%,D类微生境（臭柏灌丛地）最低为77.59%;（2）4类微生境间臭柏种群分化较小,微生境间遗传分化系数（Gst）为0.1187,88.13%的遗传变异存在于微生境群内,根据4类微生境中臭柏种群间的遗传分化系数计算的基因流（Nm^＊）为3.7122,表明不同微生境中臭柏种群存在着广泛的基因流;（3）聚类分析显示,微生境相近的种群聚到了一起,反映了臭柏种群的遗传分化和微生境有着密切的关系.（4）由RAPD分析获得的4类微生境中臭柏种群的香农多样性指数和Nei基因多样度分别在0.3768～0.4484和0.2488～0.2957之间变动.

In order to reveal the relationship between molecular variation and different habitats,4 different populations of Sabina vulgaris of Maowusu sandy land on molecular ecology were studied by using Random Amplified Polymorphic DNA（RAPD）.Sixteen random primers were selected in the ampliphication,and 174 repetitive loci were produced in which 167were polymorphic.The data were analyzed by the POPGENE3.2 Version1.31.The results showed that：（1） the genetic diversity of Sabina vulgaris population was high and changed with the habitat which changed regularly.the percentage of polymorphic loci in each S.vulgaris population ranged from 77.59% to 89.08 %.The highest is Salix cheilophila shrubs（A） population,the lowest is S.vulgaris shrubs（D） population;（2） The genetic differentiation among populations was small,Gst=0.1187,88.13% of which were within the populations;（3） The results of cluster analysis demonstrated that the populations of similar habitat clustered together,which revealed that genetic differentiation was closely related to the habitat.The largest variation was found in the populations indicated by Nei index.The gene diversity ranged from0.2488～0.2957;The gene flow（Nm^＊） was 3.7122〉1 and indicated more gene exchange among populations,which prevented genetic differentiation among populations of different habitats.