Abstract:Using inter-simple sequence repeat (ISSR) molecular technique, six subpopulations of Torreya jackii(Taxaceae) collected from Baiyunyuan Forest Park of Tonglu county of Zhejiang province were analyzed, the genetic structure of T.jackii was revealed in small scale. Using 12 primers, 87 polymorphic loci from total 194 loci were detected in 120 individuals from 6 subpopulations and the overall percentage of polymorphic loci (P) was 44.85% with an average of 29.21%. Shannon’s information index (I) and Nei’s gene diversity (h) of T.jackii were 0.166 3 and 0.103 5 with an average of 0.119 9 and 0.075 5, respectively. P, I and h indicated that the genetic diversity at species level was relatively high, while at subpopulation level was relatively low. Analysis of molecular variation (AMOVA) suggested that the variation was 21.45% among subpopulations and 78.55% within subpopulation. The coefficient of gene differentiation (Gst) was 0.270 5 among subpopulations and the gene flow was 1.347 8. The mean genetic distance of six T.jackii subpopulations was 0.037 0. Based on the genetic distance, the clustered result for six T.jackii subpopulations by unweighted pair group method arithmetic average (UPGMA) suggested that the subpopulations in the similar habitat were clustered together.