| 其他摘要 | Phylogeography is a field of research mainly focuses on the principles and processes of the genealogical distribution. The results from phylogeographic research are conducive for several studies, such as the speciation, estimation of biodiversity, conservation, and so on. Southern China harbored several important geological events and complex geographical fealture. However, phylogeographic research in this region is limited and mainly focuses on the plant. We used the Quasipaa, the spiny frog broad distributed in southern China, to study the influence caused by paleoclimatic and paleogeological events from interspecific and intraspecific scales. Our research showed that Quasipaa in southern China harbored cryptic species diversity, which implied that the biodiversity in sourthern China was still need to investigate. Besides, the paleogeological and paleoclimatic events were main drivers of genetic structuring in Quasipaa. In chapter one, we mainly introduced the Phylogeography. From first proposed to rencent development of this field, we introduced the concept, contents, research significance, the general research ideas, new methods, and some empirical model. In addition, we summarized the research situation of the phylogeography in southern China, and introduced the application and value of amphibians in this field. In chapter two, we studied the interspecific phylogeography of Quasipaa in southern China. We collected 120 samples from 59 locations throughout the range of Quasipaa in southern China. Using one mitochondrial gene and two nuclear gene fragments as molecular marker, we constructed mitochondrial phylogeny and nuclear network diagram, calculated the genetic divergence of Quasipaa, and estimated the divergence time. The results revealed the cryptic species diversity in southern China. The main factors affected the lineage divergence is the formation of monsoon climate and the difference between the secondary and third terrain in southern China. For the sustainable survival of Quasipaa, some species and areas should be priority protected. In chapter three, based on the previous study in last chapter, we studied the intraspecific phylogeography of Quasipaa boulengeri. We obtained a total of 340 samples from 45 locations after further samples collected. Using a mitochondrial genes and a nuclear gene intron fragment, we constructed phylogenetic relationship, calculated the genetic differentiation, estimated the spatial and temporal history, and simulated the population historical demography by three methods. The results reveal the old genetic divergence, which mainly caused by the geologic events in southwestern China. The paleodrainages development, unification of the upper and middle Yangtze River in the Three Gorges mountain region, mediated downstream colonization of Quasipaa boulengeri. While pleistocene climatic oscillations do not appear to be of consequence for this species. Besides, our results show the southwestern area of Sichuan Basin is the area of secondary contact for several matrilines, and this area deserves further study and special protection. In chapter four, we summarize the research of this paper, specially suggested that southern China is important in the global biodiversity conservation, this region is needed in-depth and comprehensive study. At the same time, based on the present results, we proposed the next step of work. The contact zone is a natural platform for the research of speciation, we could use the methods based on the second generation sequencing to study the molecular mechanisms of speciation. |
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