Molecular Phylogeny Of Subtribe Goodyerinae(Orchidaceae:Orchidoideae:Cranichideae)

The subtribe Goodyerinae(Orchidaceae:Orchidoideae)consists of ca.38 genera with more than 800 species,and it is a worldwide distribution.Most species of this subtribe are terrestrial,occasionally lithophytic and rare epiphytic herbs.They usually have creeping rhizomes and fleshy root.Many of the softleaves have colorful leaves and reticulate or parallel venations.The floral structure is unique,having saccate lips or a spur at the base,and often contain erect anther,rostellum and sectile pollinarium.Since the wide geographical distribution of Goodyerinae and the relatively difficult of sampling,the previous research mainly focused on the morphological stage,and few studies on the molecular level,which is the only molecular system on subtribal level.Moreover,this subtribe possesses the only one pollinia fossil of orchid.The molecular phylogenetic analysis of this subtribe is not only expected to perfect the system of Orchidaceae,but also provide the history of the evolution and species diversity mechanism of orchid with new evidence.Utilizing two nrDNA(ITS and Xdh)and four cpDNA(matK,trnL-F,rbcL and psaB)and sampling of 92 species in 22 genera of Goodyerinae,we first establish a molecular phylogeny of Goodyerinae.(1)It is the first time to solve the development formation of Goodyerinae through molecular phylogeny,presented as Pachyplectron alliance,Goodyera alliance,Gonatostylis alliance,Cheirostylis alliance,and Ludisia alliance;,the five main branches.(2)This study indicates the genera Goodyera R.Br.are polyphyletic.Based on the molecular phylogeneticand morphology,our study suggests that Leucostachys procera(Gawl.)Hoffmanns and Erythrodes viridiflora(Blume)Schlechter should be recoved.In addition,we suggest establish a new combined Erythrodes seikoomontana(Yamamoto)Q.X.Guan&S.P.Chen.(3)Molecular phylogenetic relationships support the evolutionary line of stigma in Goodyerinae:evolved from an upright stigma to two,but the Ludisia alliance is composed of a upright stigma evolved into a twisted stigma,and then evolved into the two stigma.The evolutionary line obviously does not support the traditional standpoint which used stigma quantity and twistingl upright form to describe the evolution and relationship of the subtribe.(4)Based on the molecular phylogeneticand morphology,we found and describe a new species of Goodyera——Goodyera malipoensis Q.X.Guan&S.P.Chen,sp.nov.(5)Molecular phylogeny shows the American groups(Aspidogyne,Microchilus and Kreodanthus)which is similar to the pollen stingless bees amber fossils characteristic as a separate clade.In this study,the fossil time 17.50(20-15)Mya are provided on the node and crown of Americas branch.The results obtained are shown earlier(ca.25 Mya or ca.16Mya)than the previous set using the fossil as the nodeand crown of Goodyerinae.The results are of great value to research the evolutionary history and diversity of orchids.