Study On Genetic Diversity Of Pinctada Martensii Dunker

In order to have an insight into genetic diversity of pearl oyster, Pinctada martensii Dunker, Random Amplified Polymorphic DNA (RAPD) analysis was applied in investigating its three natural populations. 18 random primers, each containing 10 nucleotide were used in this study. Six of the primers could carry on RAPD amplification, producing the amplified bands of DNA fragments with 0.2kb to 3.0kb. The six primers all produced polymorphic products among individuals of both the different populations and the same population. The genetic similarity of the three populations were 0.672(Group D), 0.641(Group 5), and 0.688(Group B) respectively, and the Shannon's index of phenotypic diversity(Ho) in three populations were 23.791(Group D), 30.018(Group 5), and 19.666(Group B) separately, illustrating that the sequence of the genetic diversity was Group S> Group D> Group B. The inter-population similarity were 0.592(Group D vs. Group 5), 0.619(Group D vs. Group B), and 0.537(Group S vs. Group B) separately. Inter-population similarity was lower than intro-population similarity. At the same time, the difference of intro-population similarity between Group D and Group B was not significant (P>0.05) while the difference of intro-population similarity between Group D and Group S and that between Group S and Group B were significant(P<0. 05), showing that Group D and Group B were genetically closed to each other and the two Groups differed from Group S genetically to a certain degree. This study also revealed that the average degree of shell-convexity could display the population's morphological characteristics and it could be regarded as a kind of morphological marker. The sequence of the average degree of shell-convexity in three populations was Group D> Group S > Group B. Besides, highly significan difference (P<0.0l) couldbe fOund in comparisons of the pairing among the three populations.Furthermore, discussions, which referred the method of conservingshellfish muscle tissue in alcohol for axPD, the speciality andinflexibility of RAPD electrophoretogram bands, the genetic diversity ofnaforal populations of Pinctada martensii Dunkr, and the possibility ofestablishing relations betwCen the morphological marker and the geneticmarker in Pinctada martensii Dunker, were made.