Genetic diversity of three endemic and endangered species of the family Theaceae in Guangdong, China
山茶科3种中国特有濒危植物的遗传多样性研究

Euryodendron excelsum , Apterosperma oblata , and Camellia changii are three species of the family Theaceae endemic to China. Genetic diversity of the three endangered species was studied using random amplified polymorphic DNA (RAPD). A total of 206-305 bands were generated by 20-24 random primers. Percentages of polymorphic loci( PPL ) of the three species were 51.80%, 80.26% and 38.83%, respectively, and coefficients of gene differentiation ( G ST ) were 0.3566, 0.1713, and 0.1242 , respectively. The results indicate that Apterosperma oblata , with wider natural distribution, has higher genetic diversity than the other two species with restricted natural distributions. Genetic variation mainly existed within populations; however, population genetic differentiation was obviously higher in Euryodendron excelsum than in the other two species, which possibly resulted from habitat fragmentation. Based on the different genetic structure, we put forward some conservation strategies, including in situ preservation, establishing a conservation centre for endangered species of the family Theaceae in Guangdong, and developing fast propagation techniques.