Genetic Diversity And Genetic Structure Of Three Veneridae Species In The Coastal Water Of China Sea

Veneridae was one of the economic shellfish in China's coastal areas,It was widely distributed in the coastline and estuary of China.In recent years,their resources have been declining because of the intensification of marine pollution,over-fishing,and destruction of habitat.At present,12 species such as Meretrix meretrix and Cyclina sinensis have been cultivated.In addition,there were many clams With potential development value.Nowdays the research of Curtainidae mainly focuses on nursery and aquaculture techniques,Basic research is still lagging behind.In this study,the genetic diversity of three species of Meretrix lamarckii,Meretrix meretrix and Gomphina aequilatera were analyzed by mitochondrial DNA markers.The main results are as follows:1.We obtained 582 base pairs of COI from 138 individuals of M.lamarckii,comprising15 polymorphic sites and 28 haplotypes,and 1168 base pairs of Cytb from 125 individuals of M.lamarckii,comprising 18 polymorphic sites and 22 haplotypes.The haplotype and nucleotide diversities of COI were 0.733±0.035 and 0.00304±0.00023,respectively,and of Cytb were 0.789±0.036 and 0.00211±0.00018,respectively.F-statistics showed that the Zhoushan?ZS?and Xiangshan?XS?populations significantly genetically differed from the Wenzhou?WZ?,Zhangpu?ZP?,Shantou?ST?,and Zhanjiang?ZJ?populations?P<0.01?,excluding XS and ZJ in COI and Cytb and XS and WZ in Cytb?P>0.01?.The same results shows in the net-work,UPGMA trees and structure.Analysis of molecular variance indicated that 81.81%in COI and 80.90%in Cytb of the genetic variance was within populations?P<0.05?.Thus,there is significant genetic diversity in M.lamarckii in the China Sea.2.We obtained 672 base pairs of COI from 122 individuals of M.meretrix,comprising33 haplotypes,and 685 base pairs of Cytb from 134 individuals of M.meretrix,comprising33 haplotypes.The haplotype and nucleotide diversities of COI were 0.968 and 0.01697,respectively,and of Cytb were 0.959 and 0.01288,respectively.F-statistics showed that the Qingdao?QD?,Yancheng?YC?and Nantong?NT?populations significantly genetically differed from the Zhangzhou?ZZ?,Zhuhai?ZH?,Beihai?BH?,and Haikou?HK?populations?P<0.05?.The same results showed in the net-work,UPGMA trees and structure.Analysis of molecular variance indicated that 93.12%in COI and 90.91%in Cytb of the genetic variance was within populations?P<0.05?.3.We obtained 685 base pairs of COI from 77 individuals of G.aequilatera,comprising 37 polymorphic sites and 33 haplotypes,and 350 base pairs of 12S rRNA from81 individuals of G.aequilatera,,comprising 4 polymorphic sites and 7 haplotypes.The haplotype diversity of COI showed high diversity,The haplotype diversity of 12S rRNA showed a middle level.F-statistics showed significantly genetically differed from the COI gene,especially in ZS and BH populations(F_ST=0.444).It showed the same results in 12S rRNA gene.The net-work shows that ZS and BH populations had a significantly difference,this was consistent with the F_ST analysis results.The analysis of molecular variance showed that there were significant genetic differences within and among populations.