Population Genetic Diversity Of Scylla Paramamosain In Guangxi Coastal And Its Neighbouring Seaareas

Objective：In order to study genetic information and gene diversity of Scyllaparamamosain In in Guangxi coastal and its adjacent area,ISSR、RAPD and16sRNAwere used in this study，Providing data Support for the protection of germplasmresources and breeding.Methords:1. ISSR-PCR technique was employed to investigate genetic diversityand population structure of six Scylla paramamosain geographic stocks in Guangxiand its neighbour sea areas.2. Random Amplified Polymorphic DNA technology wasemployed to investigate the genetic diversity and structure of six geographicpopulations of Scylla paramamosain in Guangxi and its neighbour sea areas.3.Mitochondrial16SrRNA gene fragment was employed to analyze genetic diversityand population structure of six Scylla paramamosain geographic stocks in Guangxiand its neighbour sea areas.Results:1. Total111individuals were amplified by eight ISSR primers.66validloci were analyzed, of which56were polymorphic. The percentage of polymorphiclocus (PPL) was84.85%at the species level. The PPLs of six populations rangedfrom51.52%to63.64%with an average of57.58%.The abundance of geneticdiversity in the six populations arranged in a decent order was QH> DJ>QZW>LSW>ZZW>ZK.Total coefficient of gene differentiation value was0.1841(Gst=0.1841). An analysis of molecular variance (AMOVA) showed that variance withinpopulations accounted for87.97%and variance among populations accounted for12.03%.Total gene flow (Nm=2.2164) and those from comparison of two populations(Nm=2.7348-6.7574).2. RAPD results showed that A total of99individuals were amplified using8randomprimers with10bp in length.44valid loci were analyzed, of which thirty-one arepolymorphic. The percentage of polymorphic locus (PPL) is70.45%at the species level. The PPL in six populations ranges from29.55%to54.55%with an average of36.97%.The abundance of genetic diversity in the six populations arranged in a decentorder is QZW>DJ>ZZW>ZK>QH>LSW. An analysis of molecular variance(AMOVA) shows that variance within populations accounts for87.03%and varianceamong populations accounts for12.97%.3.16SrRNA fragmengt from mitochondrial genes of Scylla paramamosain sampledFrom Guangxi coastal and its adjacent area were amplified. The total16SrRNA genelength was528bp an21haplotype were obtain from113indviduals collecting in sixdifferent regions The average haplotype diversity (h) and nucleotide diversity (π)was0.6259,0.001851, respectively. The high level of Nm values (-51.29-95.23) andlow Fst values (-0.1400-0.02977), the average K2-P distances (0.0006-0.0016), aswell as the AMOVA analysis (total Fst=0.00102P <0.01).Conclusions:1.Three molecukar markers showed that genetic diversity of S.paramamosain had arrived at a higher level within the crustacean, but was lower thanthose of other several marine animals of economic importance revealed by the sametechnique.2. An analysis of molecular variance (AMOVA) showed that variance withinpopulations was higher than that among populations. There was an effective geneflow among six populations. Mantel test showed that no significant correlation wasdetected between genetic distance and geographic distance in the six Scyllaparamamosain geographic stocks.3. Nuclear DNA markers (ISSR, RAPD) and the mitochondrial DNA markers revealsthe same group genetic background show some of the difference, from nuclear DNAmarker scanning the entire genome, and mitochondrial gene markers loci in the singlegene locus.