Study On Resources Status Survey And Population Genetic Diversityof Wild Camellia Jponica In East Asia Islands

Camellia japonica L. is an important horticultural species, which has high ornamental value and ecological value, and it can be used as parent to cultivate new varieties. At present, under the effect of both of natural and man-made factor, the number and distribution of C. japonica populations is decreasing dramatically. Therefore it is urgent and necessary to do a systematic research on its current status quo and the genetic diversity so as to propose conservative strategies to protect it. Based on integrated investigations and ISSR analysis of C.japonica in East Asia, the main results were as follows:1. The study showed that wild C.japonica distributes mainly in China’s eastern coastal areas and southern areas of Japan and the Korean peninsula, and vertically distributes between the elevations of0m and1500m. Zhoushan Islands is the natural center of distribution of C.japonica, with more than0.3million individuals. Xiangshan also has some natural C.japonica populations, but most were severely damaged. There are many Camellia trees in Changmenyan Island, but few of them are saplings. A considerable number of Camellia trees grown in the southern Japan, and they are in a good growing situation.2. Investigated the ancient Camellia trees in some provinces of China, and than analyzed the relationship of different ancient Camellia varieties in Chongqing Municipal. Survey result showed that there are a large number of ancient camellia trees in some China’s southern provinces, but some of the ancient trees are suffering from the destruction of man-made or natural factors, it is necessary to take appropriate measures to protect this kind of resources.3. By using inter-simple sequence repeat (ISSR) markers to determine the genetic diversity and genetic differentiation of390individuals in13populations of C.japonica. A total of211discernible loci were obtained using20primers, the percentage of polymorphic loci (PPL) was estimated up to90.05%. As analyzed by POPGEN, Nei’s genetic diversity (HE=0.3414) and Shannon information index (H=0.5013) indicated that C.japonica had a high level of genetic diversity at species level. Genetic diversity difference among populations was relatively high based on the percentage of polymorphic loci (PPL) ranged from66.35%to77.25%, Nei’s gene diversity index ranged from0.2344to0.2966, and shannon’s information index ranged from0.3478to0.4319, the genetic diversity levels of Japan populations were higher than China populations. Genetic differentiation cofficient among populations was0.2127, which indicated that genetic differentiation mainly occurred within populations, Gene flow value was0.9255, affirmed that insular geographical isolation had great influences and significant correlation was found between genetic distance and insular geographic distance (r=0.8154, P<0.05). UPGMA indicated that CMY, BG and WS populations had a close relationship each other, proved that BG population and WS population were transplanted from Changmenyan Island.