Population Genetics Of Wild Marsupenaeus Japonicus In The Southeastern Coastal Waters Off China

The assessment of genetic diversity and genetic differentiation of M.japonicus is of great significance for germplasm resources protection and breeding. But studies on M.japonicus in China is still focusing on the fishery biology, aquaculture science biology and discharging of M.japonicus today when there is little publications about germplasm resources .So we uses Allozyme technology and AFLP technology to assess the genetic diversity and genetic differentiation of wild populations of M.japonicus in the southeastern coast of China.Allozyme of M.japonicus in the southeastern coast of China was investigated using the assay of vertical slab polyacrylamide gel electrophoresis. 22 allozyme loci and 31 alleles was scored from 10 enzymes of M.japonicus ,which contains 17 monomorphic loci (Adh-1,Adh-2,Aat-1,Aat-2,Mdh-2,Me-1,Me-2,Me-3,Ldh-1,Per,Amy-1,Amy-2,Amy-4,Sod-2,Sod-3,Sod-4,Sdh-1)and 5 polymorphic loci(Sod-1,Est-1,Est-2,Amy-3,Mdh-1).The percentage of polymorphic loci is 22.73%. Results also show that the genetypic distribution observed at Est-2 in the population of Shantou,Mdh-1 and Sod-1 in the population of Beihai,Mdh-1 in the population of Meizhou,Sod-1 in the population of Lianjiang,Mdh-1 in the population of Zhangpu are found to be in agreement with the Hardy-Weinberg equilibrium(P>0.05).But other polymorphic loci in the 9 populations are found to depart clearly from the Hardy-Weinberg equilibrium(0.010)when heterozygote excess exists in locus Amy-3 and Est-1 in the 9 populations(except Est-1 in the Quanzhou population)(F<0).It indicates that the heterozygous of M.japonicus is in a good situation.Genetic diversity and differentiation in nine populations of wild M.japonicus in the southeastern coast of China were investigated using the assay of vertical slab polyacrylamide gel electrophoresis,too.The effective number of alleles per locus (Ae) and mean effective number of alleles per locus are 1.1137～1.2012,1.1463,respectively; the percentage of polymorphic loci (P) and mean percentage of polymorphic loci are 13.64～22.73%,18.18%,respectively; the observed heterozygosity (Ho) and mean heterozygosity are 0.0742～0.1121,0.0907,respectively; the expected heterozygosity (He) , mean expected heterozygosity are 0.0573～0.0930 , 0.0714,respectively; the populations genetic distance is between 0.0002 and 0.01230; the Nei's genetic identity is 0.9878～0.9998; FST is 0.0432; gene flow (Nm) is 5.5406.Genetic variation and diversity of 10 populations of wild M.japonicus in the southeastern coast of China were analyzed and compared by AFLP. A total of 678 loci were detected from 300 individuals;the effective number of alleles per locus(Ae) and mean effective number of alleles per locus are 1.2514～1.3456,1.29567,respectively; the percentage of polymorphic loci(P) and mean percentage of polymorphic loci are 67.55～80.68%,75.958,respectively;the Shannon's Information index (I) and mean Shannon's Information index are 0.2523～0.3322, 0.29353,respectively;the Nei's gene diversity(H) and mean Nei's gene diversity(H) are 0.1581～0.2136,0.1852,respectively;the genetic distance between populations(D) and mean genetic distance between populations are 0.0225～0.1427,0.0918,respectively; FST is 0.2577;gene flow (Nm) is 1.4400.All above indicates that the diversity of the wild populations of M.japonicus in the southeastern coast of China is in a good situation but a little divergency has taken place.