GENETIC DIVERSITY OF THE POPULATIONS OF TSOONGIODENDRON ODORUM
观光木种群遗传多样性研究

Genetic diversity of four populations of Tsoongiodendron odorum, Nankunshan and Chebaling of Guangdong Province, Jingxi of Guangxi, and Bawangling of Hainan Province was examined by Random Amplified Polymorphic DNA (RAPD). A total of 224 sites were detected from 108 individuals in four populations by 45 10_mer primers, 175 of which were polymorphic (78.13%). Polymorphic percentage of the four populations was 47.89% (Hainan), 53.96% (Jingxi), 55.00%(Chebaling), and 56.35% (Nankunshan), respectively. Species diversity indicated by Shannon index was 0.3565, 36.58% of which was from the inter_populations, 63.42% of which was from the inner_populations. Species diversity indicated by Nei index was 0.2597 and the coefficient of gene differentiation ( G ST ) among the populations was 0.2701. The genetic distance between Chebaling and Jingxi population was the largest (0.2775) while that between the two populations of Guangdong province, Nankunshan and Chebaling, was the smallest (0.0590). It was concluded from the present study that there exists high genetic diversity in the natural populations of T. odorum. Low genetic diversity is not a key factor threatening its natural populations. The major factors threatening the development of T. odorum include direct damage to natural population due to destruction of habitat and poor regeneration ability caused by innate biological and ecological characteristics.