Abstract: By using inter-simple sequence repeat (ISSR) markers technique, the genetic diversity of five populations of endangered relic shrub Liguidambar fornosana was studied in this paper. Using 10 primers, ISSR amplification was conducted in 100 individuals from 5 L.fornosana populations and 118 polymorphic loci were detected from total 135 loci. The total percentage of polymorphic loci(P) was 87.41%. The mean of Shannon’s Information index(I) and Nei’s gene diversity(h) at population level was 0.366 0 and 0.254 3. It suggested that the genetic diversity of BS population was the highest while that of TTS population was the lowest. Analysis of molecular differences showed that 85.49% was distributed among individuals within populations, while only 1451% was distributed among populations, The gene differentiation coefficient (G_st) among populations is 0.185 6. The gene flow among populations is 2.194 4. The average genetic distance of 5 populations was 0.119 9. Using unweighted pair group method arithmatic average(UPGMA), BYS population, TTS population, BS population and ADH population were clustered into one group; the DMS population was clustered into another group.

Key words: Liguidambar fornosana, genetic diversity, genetic differentiation, ISSR