Abstract: In this study, mitochondrial DNA cytb gene and D-loop sequences were used to investigate the genetic diversity and genetic structure of White bream Parabramis pekinensis populations from 4 major spawning grounds (Yidu, Shashi, Yanwo, Tuanfeng) in the middle Yangtze River. The results showed that 82 polymorphic sites and 86 different haplotypes were identified among mtDNA cytb sequences, and the average haplotype diversity (H_d) and average nucleotide diversity (P_i) were 0.930 and 0.00244, respectively. Forty six polymorphic sites and 76 different haplotypes were identified among mtDNA Dloop sequences, and the H_d and P_i values were 0.972 and 0.00505, respectively. Analysis of molecular variance (AMOVA) and haplotype network structure suggested that most of the genetic variation in the four populations was within groups, with no significant genetic divergence among populations. Meanwhile, pairwise average Kinura 2parameter distances, the F_ST value and N_m value also revealed that genetic exchange existed among populations. The neutral test showed that historical population expansion occurred in P. pekinensis, and the expansion appeared in the late Quaternary glacial period.

Key words: Ar Horqin , conservation efficiency, rapid assessment., landscape dynamic, nature reserve