Abstract:In order to evaluate genetic diversity of Camellia oleifera resources in Hainan Island, the genetic diversity and relationship among 31 populations were analyzed by using SRAP molecular marker. The results showed that the genetic diversity of C. oleifera resources in Hainan Island was low, the percentage of polymorphic bands (PPB), Nei's genetic diversity index (H) and Shannon's information index (I) were 98.30%, 0.222 8 and 0.353 8 at the species level, and 40.96%, 0.138 5 and 0.208 3 at the population level, respectively, which was inconsistent with their rich phenotypic diversity in Hainan. The coefficient of genetic differentiation among populations (Gst) was 0.380 5, and the gene flow (Nm) was 0.813 9 between different populations, indicating that genetic differentiation was high with limited gene flow among populations. The genetic variation mainly existed within populations (61.95%) and few among them (38.05%). The genetic distance ranged from 0.022 6 to 0.276 4, with the mean of 0.107 7 between 31 populations, which revealed the relatively close genetic relationship among the populations. UPGMA cluster analysis showed that 31 populations could be divided into 6 groups at the genetic distance of 0.11, showing obvious administrative area, but had little to do with geographical distance. So, it was suggested that the relatively close genetic relationship of C. oleifera resources in Hainan Island might cause self-incompatibility, which could be the main internal cause for blooming but low yield of C. oleifera forests in Hainan Island.