短枝木麻黄群体的遗传分化和遗传结构

Genetic differentiation and structure of Casuarina equisetifolia populations

利用RAPD技术对4个短枝木麻黄(Casuarina equisetifolia)种群的遗传分化和群体遗传结构进行了分析。结果表明,短枝木麻黄具有较高的遗传多样性,但各种群的遗传多样性大小不一,由大到小依次为天然分布于澳大利亚、太平洋群岛的原生种群(YSAP)>引种于亚洲的次生种群(CSAS)>引种于非洲的次生种群(CSAF)>天然分布于东南亚的原生种群(YSAS)。遗传变异分析表明,短枝木麻黄群体的遗传变异主要存在于群体内,种群间遗传多样性比例(Hsp-Hpop)/Hsp=0.246,遗传分化系数GST=0.263,种群间变异比率φST=0.278 9,即群体内变异占了72.11%,群体间变异占27.89%。UPGMA聚类分析将4个短枝木麻黄种群归为2类,YSAS与CSAS的亲缘关系较密切,而YSAP与CSAF有着更亲密的关系,这在一定程度上反映了次生种群的主要引种来源。

Genetic differentiation and population genetic structure from 4 populations of Casuarina equisetifolia were studied by RAPD markers. The results showed that high genetic diversity in C. equisetifolia. The order of genetic diversity was natural populations from Australia/Pacific （YSAP） 〉 introduced populations from Asia （CSAS） 〉 introduced populations from Africa （CSAF） 〉 natural populations from South-East Asia （YSAS）. The genetic variation of C. equisetifolia populations mainly existed within populations. （Hop - Hpop ）/Hsp, GST and φST were 0. 246, 0. 263 and 0. 278 9 respectively. Therefore, it was apparem that variation within population accounted for 72. 11% and variation among populations accounted for 27.89% of the total genetic diversity. Based on UPGMA cluster analysis, 4 C. equisetifolia populations were divided into 2 groups. YSAS and CSAS, YSAP and CSAF showed closed geographic relationship, respectively.