木荷种群在演替系列群落中的遗传多样性

利用ISSR分子标记对木荷种群在3个演替系列群落中的遗传多样性进行了研究。12个随机引物共检测到203个可重复的位点，其中多态位点183个，总多态位点百分率（P）为90.15%，平均多态位点百分率为82.27%。Shannon信息指数（I）估算的总遗传多样性为0.524 4，平均为0.477 8。Nei指数（h）计算的总基因多样性为0.358 7，平均为0.326 5。3个种群的P、I、h大小顺序均为针叶林>针阔混交林>常绿阔叶林。AMOVA分子变异显示91.56%变异来源于种群内，8.44%变异来源于种群间。种群间的遗传分化系数（G_ST）为0.089 7，基因流（N_m）为5.073 1。种群间的遗传相似度平均为0.928 4，遗传距离平均为0.074 4，针叶林种群与针阔混交林种群遗传相似度最高。

Genetic Diversity of Schima superba Populations in Three Forest Communities at Different Succession Stages

Inter-simple sequence repeat (ISSR) technique was used to analyze the genetic diversity of Schima superba populations in three forest communities at different succession stages. Using 12 random primers, 203 repetitive loci were produced in 60 individuals of S. superba, among which 183 loci were polymorphic and the total percentage of polymorphic loci (P) was 90.15%. The average percentage of polymorphic loci of three populations was 82.27%. Estimated by Shannon information index (I), the total genetic diversity of three populations was 0.524 4 with an average of 0.477 8 while that was 0.358 7 with an average of 0.326 5 judged from Nei index (h). Judged from percentage of polymorphic loci and Shannon information index and Nei index, the genetic diversity of coniferous forest community ranked first, followed by coniferous and broad-leaved mixed forest community, and then evergreen broad-leaved forest. Analysis of molecular variance(AMOVA) showed that 91.56% of genetic variance was within populations and 8.44% of genetic variance resided among population. The coefficient of gene differentiation (G_ST) was 0.089 7 and the gene flow (N_m) was 5.073 1. The mean of genetic identity among 3 populations of S. superba was 0.928 4 and the mean of genetic distance was 0.074 4, The genetic identity between the coniferous forest community and the coniferous and broadleaved mixed forest community was the highest.