裸果木种群遗传多样性特点及与地理气候因子关联研究

Study on the Relevance between Genetic Diversity of Gymnocarpos przewalskii Populations and Geographic Climatic Factors

本文利用ISSR标记技术,选取15对引物,对分布于西北荒漠区12个裸果木种群的遗传多样性以及与地理气候因子的相关性进行了分析。结果表明:群体内多态性位点百分率(PPL)为88.81%,种群水平为69.93%;Nei’s基因多样性指数(He)变化范围为0.2356~0.2697,Shannom信息指数(I)变化范围为0.3509~0.4057,具较高的遗传多样性水平。基因分化系数(Gst)为0.2790,种群间遗传分化较小,种群内存有丰富的遗传变异。经Mantel检验,种群遗传距离与地理距离有相关性(R2=0.2144)。利用NTSYSpc-2.1软件进行UPGMA法聚类,各种群样品间的遗传相似系数在0.81~0.99之间,按照遗传距离远近,裸果木12个种群可分为4大类群。经相关性分析,种群遗传多样性与纬度、海拔存在正相关(P<0.05)与年均温存在负相关(P<0.05)。

To study 12 species of Gymnocarpos przewalskii in Northwest desert area,15 pairs of primers selected by ISSR marker were used to analyze the correlation of genetic diversity and geographic and climatic factors.The results showed that the polymorphic loci percentage（PPL）was 88.81%,the population level was 69.93%;and the variation range of Nei＇s gene diversity index（He）was 0.2356~0.2697.The variation range of Shannon＇s Information index（I）was 0.3509~0.4057,which indicated high genetic diversity.The coefficient of gene differentiation（Gst）was 0.2790,with a small genetic differentiation between each group and a rich genetic variation in group.Mantel test showed that the population genetic distance was related to geographical distance（R^2=0.2144）.Using the ntsyspc-2.1 software to do the unweighted averages（UPGMA）cluster analysis,the genetic similarity coefficient for each group ranged from 0.81 to 0.99.According to the genetic distance,12 Gymnocarpos przewalskii species divided into four groups.According to the correlation analysis,the latitude and altitude had a positive effect and average annual temperature had negative influence on the population genetic diversity.