MtDNA Cytb Diversity Of Siniperca Scherzeri From Seven Water Systems

Siniperca scherzeri is the important freshwater fish of China,it has the value in maintainthe ecosystem stability.With our economic development, environmental pollution, overfishingmaking Siniperca scherzeri wild resources dried up quickly; More and more Siniperca scherzeriare breeding in recent years, resulting in genetic diversity singleness; Artificial breedingdischarge may lead to wild Siniperca scherzeri germplasm pollution.so the protection ofSiniperca scherzeri is in great need. In this study, the sequences of complete mitochondrial Cytbwere used to analyze176Siniperca scherzeri from10geographical groups in7rivers, analyzesthe genetic diversity, genetic variation and population historical dynamic, for the purpose ofmanagement and protection wild Siniperca scherzeri resources provides the scientific basis.Results were as following:1. The length of the176Siniperca scherzeris’MtDNA Cytb is1141bp, including109variable sites(accounting for9.5%of the total number of nucleotides). The four bases(A,T,C,G)average content is24.54%,27.53%,32.53%,15.4%, having a bias against G.2. In Neighbor-joining tree,10geographic groups of176Siniperca scherzeris are dividedinto five clades, each clade has a certain distribution range. Clade1is composed of Shang Hang,main Jian Ou,main Chi Zhou group and minority Qian Daohu individuals;Clade2consists ofGuang Yuan group;Clade3consists of Nan Yuepo,Gui Ping,Ying De and minority Chi Zhouindividual;Clade4consists of Dan Dong and Qi Xian;Clade5consists of main Qian Daohu andminority Jian Ou individuals.3. In7water systems,Yangtze River include3clades, the Qiantang River and the MinjiangRiver include2clades, other water refer to1clade.The genetic distance between5clades are0.009to0.061, Fst is between0.93034-0.98082.In addition to clade2and3, the differencebetween other clades even reach subspecies or species.Genetic differentiation between NanYuepo and Gui Ping is least in clade3, Dan Dong and Qi Xian, Jian Ou and Shang Hang have amoderately differentiated but can exchange some gene, other groups have a higher degree ofdifferentiation. In Yangtze River, upstream, midstream and downstream have high geneticdifferentiation,because of geographical isolation.The analysis of molecular variance based onsamples from7water systems showed that61.22%of the total genetic variance was contributed by among water systems variation,28.27%within groups and10.51%within populations.Theanalysis of molecular variance from7water systems but take out a few individuals show that67.74%of the total genetic variance was contributed by among water systems variation29.84%within groups and only2.42%Within populations. The genetic variance of Siniperca scherzeri ismainly come from among water systems.4. All the samples show that the average haplotype is0.928±0.008and the nucleotidediversity is0.03288±0.00579. In10groups, the higher genetic diversity are Qian Daohu and GuiPing. Qian Daohu of clade5haplotype was0.0858±0.063, the nucleotide diversity was0.00237±0.00007.Gui Ping haplotype was0.914±0.079, the nucleotide diversity was0.00164±0.00065. Guang Yuan of clade2has the lowest genetic diversity.A total of34haplotypes is detected from176individuals, and5haplotypes are existed two or more groups,the other are only in one group.5. The analysis of mismatch distribution and results of neutrality test showed clade1mismatch distribution is multiple peaks and Tajima’s D value,Fu’s value is negative but the Pvalue was not significant;Clade2Tajima’s D value,Fu’s value is Nonnegative;Clade3,4and5Fu’s value is negative but the P value was not significant and mismatch distribution is multiplepeaks.Those suggested5clades do not have a obvious expansion of population in history.According from10groups, the historical population expansion occurred in Ying De group, andappeared in about235000years ago, in the late pleistocene.6. In5clades, Gui Ping,Guang Yuan, Jian Ou, Qian Daohu and Dan Dong population mightbe treated as Management Units.