Phylogeny and classification of the East Asian Amitostigma alliance (Orchidaceae: Orchideae) based on six DNA markers

BMC Evolutionary Biology

Research Article

Tomohisa Yukawa¹  Richard M Bateman²  Hua Peng³  Ying Tang⁴  Hong Jiang⁵ 

[1] Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, 305-0005, Tsukuba, Ibaraki, Japan;Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, TW9 3AB, Surrey, UK;Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China;Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China;University of Chinese Academy of Sciences, 100049, Beijing, China;Yunnan Academy of Forestry/Yunnan Laboratory for Conservation of Rare, Endangered and Endemic Forest Plants, State Forestry Administration, 650204, Kunming, Yunnan, China;

关键词: Chloroplast capture;    Classification;    Hemipilia;    Hemipiliopsis;    Incongruence;    Molecular phylogeny;    Monophyly;    Morphology;    Neottianthe;    nrITS;    Orchidinae;    Plastid;    Ponerorchis;    Taxonomic treatment;    Tsaiorchis;   

DOI  :  10.1186/s12862-015-0376-3

 received in 2015-01-16, accepted in 2015-05-08,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundTribe Orchideae dominates the orchid flora of the temperate Northern Hemisphere but its representatives in East Asia had been subject to less intensive phylogenetic study than those in Eurasia and North America. Although this situation was improved recently by the molecular phylogenetic study of Jin et al., comparatively few species were analyzed from the species-rich and taxonomically controversial East Asian Amitostigma alliance. Here, we present a framework nrITS tree of 235 accessions of Orchideae plus an in-depth analysis of 110 representative accessions, encompassing most widely recognized species within the alliance, to elucidate their relationships.ResultsWe used parsimony, likelihood and Bayesian approaches to generate trees from data for two nuclear (nrITS, low-copy Xdh) and four chloroplast (matK, psbA-trnH, trnL-F, trnS-trnG) markers. Nuclear and plastid data were analyzed separately due to a few hard incongruences that most likely reflect chloroplast capture. Our results suggest key phylogenetic placements for Sirindhornia and Brachycorythis, and confirm previous assertions that the Amitostigma alliance is monophyletic and sister to the Eurasian plus European clades of subtribe Orchidinae. Seven robust clades are evident within the alliance, but none corresponds precisely with any of the traditional genera; the smaller and more morphologically distinct genera Tsaiorchis, Hemipilia, Neottianthe and Hemipiliopsis are monophyletic but each is nested within a polyphyletic plexus of species attributed to either Ponerorchis or the most plesiomorphic genus, Amitostigma. Two early-divergent clades that escaped analysis by Jin et al. undermine their attempt to circumscribe an expanded monophyletic genus Ponerorchis.ConclusionsWe provide a new framework on the complex phylogenetic relationships between Amitostigma and other genera traditionally included in its alliance; based on which, we combine the entire Amitostigma alliance into a morphologically and molecularly circumscribed Amitostigma sensu latissimo that also contains seven molecularly circumscribed sections. Our molecular trees imply unusually high levels of morphological homoplasy, but these will need to be quantified via a future group-wide review of the alliance based on living plants if morphology is to be fully integrated into our classification.

【 授权许可】

Unknown   
© Tang et al. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.