Genetic Diversity Of Culter Mongolicus (Teleostei: Cyprinidae) In The Amur And The Yangtze River Drainages Based On Complete Sequence Of MtDNA ND2Gene

Being One of the important freshwater fish in China, Culter mongolicus has the very higheconomic value. In recent years, the impact of environmental contamination, deterioration of theclimate, human overfishing and other factors, wild population of Culter mongolicus is drasticallyreduced, the structure of Culter mongolicus becomes a single, and the germplasm resources degeneraterapidly, so the protection of germplasm resources in great need. The genetic diversity is to carry outthe material basis for the protection of biological resources and germplasm breeding, therefore theneed for Mongolia of Culter genetic diversity have a clear understanding. In this study, sequences ofcomplete mitochondrial ND2gene of199Culter mongolicus from12different locations in theHeilongjiang river and the Yangtze river conducted in-depth analysis. The results were obtained asfollowing:1. Compare to the sequence downloaded from GenBank，we confirmed the length of the ND2gene is1067bp.There are108variable sites (accounting for10.12%of the total number of nucleotides),69parsimony informative sites and39sites of a single variable were detected in the ND2genes of199samples. The four bases(T、C、A、G) average content is T23.3%, C31.2%, A32.4%, G13.0%. Analysisof the12Culter mongolicus groups genetic distance found, between0.000-0.005among groups andwithin various groups between0.000-0.004,They are at the same level, did not reach the subspeciesdifferentiation standards. There are27haplotypes in199samples. The average haplotype (Hd) was0.856±0.013and the nucleotide diversity (Pi) was0.01934±0.00162, showing a high haplotypediversity and lower nucleotide diversity. Indicated that the genetic diversity of Culter mongolicus at alow level.2. Analysis of the12Culter mongolicus groups genetic differentiation index (Fst) and geneflow(Nm) analysis showed that: in the Heilongjiang River, between the Fuyuan groups and theXingkaihu groups is a high degree of differentiation (Fst=0.3067), the performance is highlydifferentiated. It was also different from the DaXingKaiHu and the DunHua populations(Fst is0.2412and0.2061respectively), the Fst between the Lianhua and the Jingpohu populations is0.0565,showing a low degree of differentiation. AMOVA showed that, the genetic differentiation is obviousbetween the Heilongjiang River and the Yangtze River geographic populations. The variation percent between populations were28.86%, but the variation was mainly from within populations among theHeilongjiang River populations, the Yangtze River has a certain degree of genetic differentiation.Tajima’s D and Fu’s neutrality test and the nucleotide mismatch distribution analysis diagram resultsrelvealed that Culter mongolicus had experienced population expansion as a whole population. Theexpansion-time from50000to60000years,as the late Pleistocene.3. The genetic diversity of HeJiang population is the most abundant, so we should to focus on theprotection. The genetic diversity of TaiHu, YunXian, AnKang and MiLuo populations were more rich,we also must strengthen the protection. The gene exchanged frequently in XingKaiHu andDaXingKaiHu populations, so we should set up nature protection areas in order to facilitatemanagement of protection.