Genetic Diversity Of Wild Populations Of Channa Argus In China

Channa argus is an important freshwater fishes and widely distributed in China, theYangtze River and Minjiang River to the north of the Lakes and rivers and the Korean Peninsula.In this study, the sequences of complete mitochondrial ND2sequences were used to analyze thegenetic diversity of174Channa argus in17different geographical groups from Yangtze to theHeilongjiang river. Results were as following：1.1013conservative sites and30variable sites （included13single variable sites and17parsimony informative sites）were detected in the1043bp length of mtDNA ND2sequences.Which encoding347amino acids, and hydrophobic amino acid ratio was significantly higherthan that of hydrophilic amino acid.A total of33haplotypes were detected from174individuals,and10haplotypes were shared by two or more groups, and the rest of haplotypes werespecific.There are8haplotypes in Wuhan of Hubei province, and6haplotypes in Miluo ofHunan and Chaohu of Anhui province. But Fuyuan Weishanhu and Saheqiao have the leasthaplotype.2. According to NJ and ME genealogical trees,33haplotypes formed distinct pedigreestructure. The total haplotype diversity (Hd) of17geographic groupsis was0.883±0.013whereasthe total nucleotide diversity (Pi) was0.00262±0.00499，and the average nucleotide diferencewas2.733, Which Demonstrated a low level of genetic diversity, and high haplotype diversitywith low nucleotide diversity pattern. Compared with other group, Yidu Wuhan Liangzihu.Miluo Taihu and Chaohu with high genetic diversity. Fuyuan Weishanhu and Dopinghu with lowgenetic diversity.3. Among17populations, the genetic distance of Fuyuan and other groups were relativelylarge, and the coefficient of genetic differentiation（Fst）were higher than0.25, and the value ofNm is less than1. Indicating that the mitochondrial ND2sequences of Fuyuan populationdifferences with other groups, and almost no genetic exchanges, Which belong to highly geneticdifferentiation. Bu this highly differentiated levels did not reach the standard of subspeciesdifferentiation. The genetic distance was0.002between Hulin and Dunhua populations, and heFst was0.1118. The genetic distance between0.001to0.002among Wuhan Liangzihu andMiluo populations, and the Fst between-0.0215to0.034. The genetic distance was0.002 between Weishanhu and Dongpinghu groups, and the Fst was0.2071. the results show that theHulin and Dunhua populations have moderate genetic differentiation as well as the Weishanhuand the Dongpinghu group, and with gene flow phenomenonï¼›The genetic differentiation wasvery small among Wuhan, Liangzihu, Miluo groups, and existed frequent gene exchanges. Thegenetic differentiation index among river systems showed that the water of the Yellow River，Huaihe River and Wei River has low differentiation and other river systems are highlydifferentiated. Analysis of molecular variance(AMOVE), the results showed the genetic variationamong populations was61.26%, genetic variation within population accounted for21.47%,genetic variation between groups was17.26%, indicating that genetic variation betweenpopulations is the main source of the total variation. Analysis of molecular variance(AMOVE)among river systems, The results showed that genetic variation mainly from river systems withinpopulations.4.Dynamic analysis of population. The results of neutral test on17groups were asfollowed: Tajima’ s Då'ŒFu’ Fs of Wuhan and Chaohu Groups were all negative and P <0.05,Which indicated that the Wuhan and Chaohu Groups have experienced expansion. the valueof Tajima’ s D and Fu’ Fs of Milo group were all negative, but only Fu ’Fs reached a significantlevel, Which showed that the Miluo group may have experienced population expansion in themore recent period, the other groups were not significant statistically. If all groups as a wholewere calculated, the value of Tajima ’s’ D and Fu Fs were negative, but did not have statisticalsignificance. According to the analysis of mismatch distribution, and also suggest that WuhanMilo and Liangzihu groups have experienced expansion. The population expansion of threegroups appeared in about8-11million years ago.