乐昌含笑种群遗传多样性的研究

Genetic Diversity of Michelia chapensis Dandy Populations

基于随机扩增多态DNA(RAPD)方法分析了珍稀木兰科植物乐昌含笑6个种群的遗传多样性及分化程度。19条随机引物扩增出111个可分析位点,多态位点百分比为81 98%,经POPGENE分析发现,乐昌含笑的Nei's基因多样度(He)为0 3255,Shannon表型指数(I)为0 4751,与其它植物比较具有较高水平的遗传多样性。6个乐昌含笑群体间基因分化系数(Gst)值为0 2226,群体内的遗传变异大于群体间的遗传变异。按照遗传距离将乐昌含笑6个群体划分为两类:第1类有广西三江、湖南宜章、湖南双牌和湖南资兴的群体,第2类包括江西官山和湖南醴陵的群体;研究表明:第2类种群的遗传多样性指数高于第1类种群的遗传多样性指数。

Michelia chapensis ,belonging to Michelia genus in the family Magnoliaceae, is a elite species for timber production and for landscaping. In this paper,the genetic diversity were investigated using RAPD technique.The total DNA were extracted following a modification of CTAB method with some adjustments. A total of 144 individuals representing 6 natural population of M. chapensis were surveyed using 19 RAPD primers.At species level,the percentage of polymorphic bands was 81.98%,Nei's gene diversity was 0.325 5 and Shannon index was 0.475 1.AMOVA showed that 29.96% of the genetic diversity resulted from differentiation among populations. The coefficient of gene differentiation(Gst)generated by POPGENE32 was 0.222 6. The 6 natural populations of M. chapensis might be divided into 2 groups used UPGMA cluster system,and the genetic diversity of second group was higher than that of the first.