Phylogeography And Demographic History Of Pelophylax Plancyi Complex In China Inferred From Cytochrome B Gene Sequence

Pelophylax plancyi species complex occurs in China,it contains three species,P.plancyi (Lataste 1880),P.fukienensis(Pope 1929) and P.hubeiensis(Fei and Ye 1982),they are endemic species to China.They are familiar,common and widespread flogs in China,distributed from Liaoning in the north to Fujian and Taiwan in the south,from Jiangsu in the east to Sichuan in the west.These species are reported to be allopatric in distribution,and morphologically very similar to each other,with only subtle differences mainly in morphological characteristics.In the past,Pelophylax fukienenis was consider as a subspecies of Pelophylax plancyi and Pelophylax hubeiensis was a synonym of Pelophylax plancyi.Both of them were elevated to species status according to some subtle morphological characteristics recently,such as tympanum of the male greater or less than the diameter of eye.Although they are listed as three different species in amphibian species of the World of AMNH(Frost 2007),no consensus regarding the systematic position of these frogs has been achieved.In order to study the speciation mode of these frogs,their genetic structures and phlogeopraphy need to be understood and explored.However,no inter-specific or intra-specific study has been conducted at molecular level so far.In this study,we design a pair of primers to amplify 741bp of cytb gene partial sequence from so called gold-striped pond frog,Pelophylax plancyi complex,which could be used to investigate molecular genetic structuring,determine levels of population differentiation,assess demographic expansions,bottlenecks and the impact of habitat fragmentation on levels of genetic variation in the isolated populations and potentially identify source populations in the species of Pelophylax plancyi group.We identified 114 haplotypes from 321 samples of 23 populations of Pelophylax plancyi complex.Most of the haplotype are confirmed to local populations,only 12 haplotypes are shared among local populations.The overall species haplotype diversity h was 0.957,and nucleotide diversityπwas 0.02716.Based on Maximum Composite Likelihood model,whole population of mean genetic distance d was 0.02891.We reconstructed phylogenetic tree based on Maximum parsimony and Bayesian method using 114 haplotypes of Pelophylax plancyi complex.Phylogenetic analyses revealed that Pelophylax placnyi complex together form a monophyletic clade.TCS network cladgram with four independent clade A,B,C and D had the identical topology to that of phylogenetic trees.According to phylogenetics relationship,We preferred these three species as a species as Pelophylax plancyi.Analysis of molecular variance and Neturality test indicated that the whole population of Pelophylax plancyi complex underwent a demographic expansion after Quaternary iceage.