| The aim of the present study was to survey mtDNA 16S rRNA sequence variation to assess genetic diversity and genetic
structure of the wild Silurus asotus in the upstream and midstream of Yangtze River. The samples of S. asotus have been obtained from the midstream and upstream of Yangtze River included the Wuyanghe (WYH), Wujiang River (WJ), Yalong Jiang (YLJ), Min River (MJ) and Chin-sha River (CS). The PCR technique was used to amplify the mtDNA 16S rRNA among 27 individuals. The PCR products were purified and sequenced. As a result, 1 680 bp nucleotide sequences of 16S rRNA were obtained. 8 haplotypes and 74 variable sites were detected among all mitochondrial 16S rRNA sequences of 27 Chinese catfish. Haplotype diversities (H) in the Wuyanghe putative population, Wujiang River putative population, Yalong Jiang putative population, Min River putative population and Chin-sha River putative population were 0.600, 0.857, 0.600, 0.600 and 0.667 respectively. Nucleotide diversities (仔) in these putative populations were 0.00072, 0.1754, 0.00036, 0.00072 and 0.01871 respectively. Tajima爷s D values showed that all putative populations fited to neutral evolution model, and FST values among all the other populations showed no strong genetic differences expect Chin-sha River (CS).Nosignificant genetic differentiation among all five putative populations were found by analysis of molecular variance (ANOVA). The ML
tree of the five putative populations showed Wujiang River (WJ), Yalong Jiang (YLJ), Min River (MJ) and Chin-sha River (CS) putative populations had the closest relation among the five putative populations, the Wuyanghe (WYH) putative populations had the greatest genetic distance among the five putative populations. |
