Abstract: 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.

Key words: Schima superba, ISSR, genetic diversity, succession