Genetic Diversity Analyses of Three Wild Populations of Pinctada martensii ( Dunker.) Using RAPD Technique
Wang Aimin1,2 Yan Bing1 Ye Li1 Deng Fengjiao3 Zhang Xiyuan3 Wu Bo4
（1. Guangxi Institute of Oceanography, Beihai 536000，China； 2. Fisheries College, Hainan University,Haikou 570228，China； 3. College of Life Sciences,Wuhan University,Wuhan 430072, China；4. Key Laboratory of Molecular Genetics, Agricultural Ministry,Guangxi University ，Nanning 530005 ，China）
Abstract：Abstract : In order to understand genetic diversity of pearl oyster Pinctada martensii （Dunker.）, Random amplified polymorphic DNA (RAPD) analysis was applied in investigating three wild populations，SW population from Sanya,Hainan, DW population from Daya Bay ,Guangdong, and BW population from Beihai,Guangxi. 18 random primers, each containing 10 nucleotide were used. Six of the primers could carry on RAPD amplification，producing the amplified bands of DNA fragments with 0.2 kb to 3.0 kb. All the six primers produced polymorphic products among individuals of both the different populations and the same populations. The genetic similarity index of three wild populations were 0.641 (SW) ,0.672(DW), and 0.688 (BW) respectively, and the Shannon's index of phenotypic diversity(H) in three populations were 0.266 (SW),0.211 (DW) and 0.174(BW) respectively.The genetic similarity of sequence was SW< DW < BW , and the genetic diversity was SW > DW >BW . The relative genetic distances were 0.104 between DW and SW, 0.094 between DW and BW, and 0.212 between SW and BW. The difference of genetic distances in these three wild populations were relative not only to their geographical distances，but also to their different habitants. According to genetic distances between populations, it was predicted that the heterosis of progenies from SW crossing BW, and SW crossing DW were higher than that from BW crossing DW. The result which genetic diversity in BW was significantly lower than that in SW and DW was from the artificial breeding and large scale farming in BW habitant. The reproduction of culturing pearl oysters from the artificial breeding disturbed the diversity of BW population. It will be paid attention to the influence of aquaculture on the genetic structure of wild populations .
