The Dispersal Pattern And Landscape Genetics Of Shangcheng Stout Salamander (Pachyhynobius Shangchengensis),with Species Delimitation Of Pachyhynobius

The Shangcheng stout salamander(Pachyhynobius shangchengensis),endemic to the Dabie Mountains,inhabit in stream environment,which is a narrowly distributed salamander.Previously,the phylogeography study of this salamander based on mitochondrial genes show the distinct population divergence.However,the genetic structure of microsatellite wasn't consistent with that of mitochondrial genes.This phenomenon maybe connected with the dispersal pattern of P.shangchengensis.Therefore,we conducted the dispersal pattern and the landscape genetics based on microsatellite data.In addition,the deep genetic divergence maybe indicated that some cryptic species exists in Pachyhynobius.Therefore,more work on the species delimitation in Pachyhynobius are needed.The doctoral dissertation contains the following main contents:(1)Dispersal pattern of P.shangchengensisOur dispersal pattern study was conducted in a senction of stream(about 600 m)in Yangtianwo of Yaoluoping area.The results of sex-biased dispersal study indicateded the male-biased dispersal pattern in P.shangchengensis.The Alc of male and female were-0.005(0.179)and 0.006(0.219),respectively.The male biased dispersal may mean the fierce compete for mate.Meantime,the landscape barrier,such as waterfall and the surface run off,should led to the genetic divergence of P.shangchengensis ·(2)The landscape genetic study of P.shangchengensisThe study was focused on the landscape genetic(298 individuals collected from 17 sampling sites)in Yaoluoping area based on microsatellite data.The spatial autocorrelation show that there was a remarkable positive autocorrelation coefficient on the 2 km distanclass,which indicated that the most dispersal behavior was confined to 2 km scale.Barrier analyses show that obviously the watershed(Yangtze River vs Huai River)was acted as an apparent geographical barrier for P.shangchengensis.Meantime,it was note worthy that the barrier effect of different sections of watershed was varied,affected by some landscape factors,such as topography and vegetative cover.(3)The species delimitation analyses of PachyhynobiusThe species delimitation were conducted based on mitochondrial genome data and morphorlogical data of P.shangchengensis,and then conbined the climate data to probe the speciation process of Pachyhynobius.The multiple methods(BFD and BPP)of species delimitation show there are several cryptic species in the genus,Pachyhynobius.Conbined the results of niche reconstruction and morphorlogical analyses,we can concluded that three species exist in Pachyhynobius.They are distributed in the areas in JTX and KHJ,the areas in TTZ and MW and the areas in BYM and KJY,which were corresponding to the northern,middle and southern of Dabie Mountains.Synthesed the history climate,the main driving force to the speciation process was the climate difference in the northern,middle and southern of Dabie Mountains,the low dispersal ability and the niche conservatism of Pachyhynobius.Through the research,we have more in-depth understanding of the landscape genetics of the salamander,and reveal the male-biased dispersal pattern,which provides important theoretical basis for the population divergence of P.shangchengensis.In addition,through the species delimitation of the genus Pachyhynobius,there are three hidden species in this genus.However,at present,this part still lacks more in-depth morphological research,which suggests the later workdirection.