Phylogenetic Systematic Study On Anoectochilus S.1. (Orchidaceae) In China

Anoectochilus s.s., Chamaegastrodia, Odontochilus and Rhomboda all belong to subtribe Goodyerinae, Orchidaceae. Taxonomic relation among these four genra was ambiguous, so they were called Anoectochilus s.l. temporarily in this study. There are about 98 Anoectochilus s.l. species in the world, and 34 species are recorded in China, 14 of them are endemic. However, taxonomic study on Anoectochilus s.l. mostly focused on morphology. In this study, ITS, trnL-F, matK. are selected as molecular markers, and then phylogenetic trees were built using the MP, ML and BI methods. Molecular methods combined with morphologic characters were applied to rebuilding the phylogenetic relationship of Anoectochilus s.l. and its related species for the first time. There were 79 orignal literatures and 384 specimens (42 type specimens) were got; 56 species 78 molecular samples and 198 DNA sequences (nine from Genbank) were referred to (43species 60 molecular samples include all of these three regions). Results showed that:1. Anoectochilus s.s., Chamaegastrodia, Odontochilus and Rhomboda are independent of each other, and possess their own identifying features. There are 14 Anoectochilus species,15 Odontochilus species,4 Rhomboda species and 5 Chamaegastrodia species distributed in China. Anoectochilus showed close relationship with Zeuxinella vietnamica and Chamaegastrodia showed close relationship to Odontochilus. Keys to genra and species, description and plates of species are provided.2. Single ITS sequences can not rebuild the phylogenetic relationship of Anoectochilus and Rhomboda, but cpDNA (trnL-F & matK) can distinguish Rhomboda species and partial Anoectochilus species. Results of holotype analysis were agree with phylogenetic trees.3. Based on present molecular results, Odontochilus were divided into 4 sections:O. sect. Odontochilus, O. sect. Pristiglottis H.Z. Tian & Q.X. Liu sect. nov., O. sect. Myrmechis (Lindley) H.Z. Tian & Q.X. Liu comb, nov., O. sect. Kuhlhasseltia H.Z. Tian & Q.X. Liu sect. nov.. These results were different a lot from Ormerod.4. Combining present molecular results with morphological characters, Pristiglottis, Myrmechis and Kuhlhasseltia should be treated as synonyms of Odontochilus, which with good agreements with Ormerod’s opinion of combining Pristiglottis with Odontochilus. Odontochilus montanus (Schlechter) H.Z. Tian & Q.X. Liu comb, nov., O. japonicus (H.G. Reichenbach) H.Z. Tian & Q.X. Liu comb. nov., O. chinensis (Rolfe) H.Z. Tian & Q.X. Liu comb. nov., O. drymoglossifolius (Hayata) H.Z. Tian & Q.X. Liu comb. nov., O. urceolatus (Tang & K.Y. Lang) H.Z. Tian & Q.X. Liu comb. nov., O. yakushimensis (Yamamoto) H.Z. Tian & Q.X. Liu comb. nov., O. nakaianus (F. Maekawa) H.Z. Tian & Q.X. Liu comb. nov. were added as new combination names.5. Two names used before (Chamaegastrodia nanlingensis H.Z. Tian & F.W. Xing, C. poilanei (Gagnepain) Seidenfaden & A.N. Rao) and two basionyms(Anoectochilus lowii R.H. Torrey ex Loudon, Odontochilus pumilus J.D. Hooker) were recovered.6. Anoectochilus xingrenensis and A. dulongensis were considered to be conspecific with A. calcareus based on the evidence of observation of morphylogy. So A. calcareus was not only distributed in Vietnam, but also in China (Guizhou, Yunnan and Guangxi).7. Molecular evindence verified systematic position of A. longilobus.8. During field trips, Chamaegastrodia shikokiana was found in Guizhou Province, and that Chamaegastrodia was a new recorded genus of Guizhou; and Odontochilus pumilus was found in Sichuan Province; Rhomboda lanceolata was a new recorded species from China. By consulting specimens, specimens of O. elwesii collected from Jiangxi Province and O. brevistylis collected from Taiwan were found.