Taxonomy And Phylogeography Study Of Sect.Goodyera(Orchidaceae)

Section Goodyera,which belonges to Orchidaceae,subfamily Orchidoideae,genus Goodyera,consists of Subsect.Goody era and Subsect.Schlechtera.There are 17 species recorded in China,including 10 endemics.Molecular methods combined with morphologic characters were applied to rebuilding the phylogenetic relationship of Sect.Goodyera.This study conducted phylogeny analysis by nuclear ribosomal internal transcribed spacer(ITS)region as well as two non-coding chloroplast regions(trnK-rps16 and accD-psal).Meanwhile,the phylogeography research of Sect.Goodyera was conducted by two chloroplast regions(1rnK-rps16 and accD-psaI).224 molecular samples of 18 species(including two outgroup sepecies Goodyera henry and G.hispidawere),56 populations,503 DNA sequences were referred to in this study.Results show that:1.Phylogenetic trees built by three methods Maximum-likelihood(ML),Maximum parsimony(MP)and Bayesin Inference(BI),combined with BI tree built by 30 morphologic characters,all support that Subsect.Goodyera and Subsect.Schlechtera are two monophyletic groups with high approval ratings.11 species of Subsect.Goodyera are independent species.Among the Subsect.Schlechtera,G robusta and G.bilamellata can separate out,G.schlechtendaliana,G.kwangtungensis and G.daibuzanensis show complex relationships.2.Molecular phylogenetic and morphology results support the division of subsections.G.bilamellata,G.schlechtendaliana,G.kwangtungensis and G daibuzanensis are treated as the same species.11 species within the Subsect.Goodyera are considered to be independent species.Bayesian three dimensional principal component analysis and cluster analysis both support this conclusion.According to the morphologic description and specimens,it is thought that G.brachystegia and G.bomiensis are probably to be the same species.Thus,G.bomiensis is treated as a synonyms of G.brachystegia.3.Chloroplast genetic molecular marker method had detected high genetic diversity of Sect.Goodyera.The nucletiode diversity(?)at species level was 0.2262,the haplotype diversity(h)was 0.790.BMLP?HGMLP and WLHLG populations show the highest genetic diversity.Populations and species differentiation level of Subsect.Goodyera are higher,while genetic differentiation level of Subsect.Schlechtera is relatively low.Subsect.Goodyera shows low gene flow(Nm=0.94),while Subsect.Schlechtera shows high gene flow(Nm=4.45).4.66 haplotypes of Sect.Goodyera were obtained.Among them,there are 34 haplotypes of Subsect.Goodyera and 32 haplotypes of Subsect.Schlechtera.Network of haplotypes of Subsect.Goodyera can be partitioned according to the species,while network of haplotypes of Subsect.Schlechtera can be broadly partitioned according to their geographical distribution.5.According to the results of the phylogeography analysis,we speculate that the species of Subsect.Goodyerais is likely to be evoluted from the G.repens,which species is ancient and widespread.They were formed to be independent species in the specific geographical environment.It is also speculated that Southwest China and Eastern Taiwan are glacial refuges for Subsect.Schlechtera populations.