Population Genetic Structure and Historical Demography of the Ground Beetle Pheropsophus jessoensis from the Tsinling-Dabashan Mountains, Central China Based on Mitochondrial DNA Analysis

The population genetic structure and demographic history of the ground beetle Pheropsophus jessoensis (Coleoptera: Carabidae) from the Tsinling-Dabashan Mountains, central China were estimated using the mtDNACoI-tRNALeu-mtDNACoII region as a molecular marker. 184 individuals from 25 local populations, were collected. The haplotype diversity (H-d) of total and each individual sampled population was high, and was accompanied by lower nucleotide diversity (P-i). AMOVA analysis suggested that most of the variation was within populations (92.17%), while differentiation of among populations only contributed 7.83% to the total. Mantel test results showed significant correlation between the pairwise calculated genetic distance and pairwise calculated geographical distance of the populations (R-xy = 0.360529, P = 0.00001 < 0.01), indicating the presence of isolation-by-distance. No phylogeographic structure was found within the Tsinling-Dabashan Mountains region. Statistical phylogeographic analysis indicated that the contemporary populations are derived from multiple ancestral-refugial source populations. Gene flow calculated through the N-m was high between many pairs of populations, which was probably due to ancient vicariance and subsequent rapid expansion of populations. The results of neutral test, mismatch distribution analyses, and Bayesian Skyline Plot (BSP) analysis together indicated a sudden demographic expansion. The estimated expansion time of individual haplogroup and the whole sampled population were 0.012-0.278 Myr, and a sudden expansion was identified between 0.05 Myr to 0.01 Myr by BSP. The postglacial population expansion might lead to the lack of phylogeographic structure.