Genetic Variance of Chinese Sucker(Myxocyprinus asiaticus)Populations in the Yangtzi River

The PCR-RFLP method was used to detect genetic structure of Myxocyprinus asiaticus populations from the 4 upper-middle reaches of Yangtze River:Yibin section,Wanzhou section,Yichang section and Wuhan section.13 types of restriction endonuclease were used in the PCR-RFLP analysis of mtDNA ND-5/6 of the 4 populations.It was discovered that the restriction types polymorphism for NciⅠ could be a special genetic marker for Myxocyprinus asiaticus.Pairwise differences and gene diversities were calculated from the polymorphism of the 4 populations,which was expounded by cleavage patterns.It was concluded that the genetic differentiation was formed between the Yibin population and other 3 populations to some extent,and the gene flow was better in the middle reaches than the upper.The genetic structure of Chinese suckers was somewhat simple and the genetic diversity tended toward continuous decline.