| Paramisgurnus dabryanus Sauvage collected from Chizhou,Guangde, Huaiyuan, Shucheng, Anhui Province and Fanxian, Henan Province were sampled as research populations. The microsatellite DNA molecular marker and mitochondrial cytochromes b (Cytb) sequence analysis were used to study genetic diversity, genetic distance, genetic differentiation, phylogeny of5populations. The results are as follows:1.The16microsatellite primers were selected to amplify40samples of each population,57alleles were found. There are2to7alleles and3.6alleles on average at each locus. The fragments of all alleles ranged from75bp to304bp, the average number of observed and effective alleles was2.2to3.6and1.6632to1.9303. The average observed and expected heterozygosity was0.0200to0.9900and0.0469to0.7061. The PIC mean value was0.2666to0.3523, it showed the low level of genetic diversity. The Chi-square test for Hardy-Weinberg equilibrium showed that5Paramisgurnus dabryanus Sauvage populations were deviated from the Hardy-Weinberg equilibrium in the most loci.The genetic distance of5populations between0.0045to0.0334, and the least (0.0045) was the distance between Chizhou and Fanxian popoulations, the largest (0.0334) was the distance between Guangde and Chizhou popoulations. UPGMA cluster diagram shows that Chizhou and Fanxian populations together, Shucheng and Huaiyuan populations together, the four populations together as a group and then meet with the Guangde population.2. The mitochondrial Cytb gene1140bp sequence of52samples from5Parami-sgurnus dabryanus Sauvage populations were analyzed and the results showed that the average contents of A, T, C and G bases were27.4,30.8,26.5and15.3, it significant anti-G bias, and the contents of (A+T)>(G+C), showed a clear preference for base composition.103variable sites were found in all52samples, and28sites were single variable site,75were parsimony informative sites. There were no nucleotide insertions and deletions were found in103variable sites, and the average ratio of transition/transversion was16.633. In all103variable sites, the mutation occurred in codon position3(85.18%of total variation), fewer bits are position1and2(7.41%of the total variance). Genetic distance analysis showed that all samples of Paramisgurnus dabryanus Sauvage genetic differences within populations, the values between0.000to0.017, and0.003to0.034between populations.The values of distance within and between all populations shows that, the values within Shucheng population was0.017, at a high level the genetic distance among Shucheng and Huaiyuan populations was0.003, at a low level.Four phylogenetic tree showed that the5populations can be classified to two parts. The genetic distance between Shucheng and Huaiyuan populations was small, they closer together and then togethered with Guangde population, they composed one part. The other part was composed by Fanxian and Chizhou populations.The individuals within Shucheng population weren’t togethered in the phylog-enetic trees. Four samples with Guangde population togethered Huaiyuan and Shu-cheng populations, and then together with the other four individuals.Genetic diversity analysis showed that the genetic diversity within5populations may be damaged in a certain degree.The values of the Nm and Fst show that the level of gene flow between Fanxian and Chizhou populations was more, the others were less. The genetic diversity of Paramisgurnus dabryanus Sauvage have begun to be destroyed.3. Integrated the analytic results of microsatellite DNA markers and mitochondrial Cytb gene sequence analysis, we can find that the genetic diversity of Paramis-gurnus dabryanus Sauvage have begun to be destroyed. So we should protect indigenous species when we developed and utilization the resources to provide protection for sustainable development of aquaculture. |
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