Abstract: Camellia japonica is an important horticultural species widely distributed in East-Asia. Five populations of C.japonica were analyzed by ISSR markers to detect the genetic structure. Twenty primers produced scorable markers were applied. The percentage of polymorphic loci, Nei’s gene diversity and Shannon’s Information Index were 70.29%, 0.281 9 and 0.409 5, indicating C.japonica had a higher level of genetic diversity than other insular plants. The coefficient gene differentiation (G_st) was 0.205 7, the effect of geographical isolation had great influences and significant correlation was found between genetic distance and geographic distance (r=0.821 7, P<0.05). UPGMA analysis revealed that populations in the same island had a close relationship. Taking examples from the experience of Japan, management strategies were proposed that natural population should be protected in situ from human disturbance to facilitate its natural generation. Constructing germplasm resources and cultivating plants mutually collected from different populations are necessary to enhance the gene flow.

Key words: Camellia Japonica, ISSR, island, genetic diversity, genetic structure