Mitochondrial DNA Divergence And Demographic History In Chinese Populations Of Black-spotted Frog (Pelophylax Nigromaculata): Implication For Pliocene Vicariance And Independent Refugia Expansion

This thesis includes three chapters:Chapter 1: The ancient global climate especially the glacial climate in Quaternary and its influence on biota are summarized.Chapter 2: The phylogeographic researches on Anuran amphibians in the world including China are reviewed.Chapter 3: This study examines the phylogeography and demographic history of black-spotted frog, Pelophylax nigromaculata, in temperate and subtropical China. We used mitochondrial cyt-b gene to conduct phylogenetic reconstruction, nested clade analysis and mismatch distributions of this frog. The deep sequence divergence (7.1%) indicates that two split lineages are included in this frog: the mainland lineage (A) and the northeast lineage (B). Lineage A is further divided into two sub-lineages with lower level of sequence divergence (0.9%), A1 and A2. Lineage A1 covers most of the species' range in China, A2 distributes to southwest plateau of China. Lineage B is restricted to part of northeast China. Deep sequence divergence indicates that the two significantly spht lineages were isolated at least before late-Pliocene when the complete separation of the Japan archipelago from East Asian mainland was finished. Nested clade phylogeographical analysis and population demographic analyses indicate the current distribution of this frog is the result of range expansion from independent rafugia after the last glacial maximum (LGM) in late Pleistocene. One refugium was east China and the low elevations ofsouthwest plateau, the other refugium, we suppose to be the Korea Peninsula. We also detected the second contact zone of lineages A and B in DL area of northeast China.