title: Molecular phylogeny and evolutionary history of the Eurasiatic orchid genus Himantoglossum s.l. (Orchidaceae).
abstract: OBJECTIVE
  Lizard orchids of the genus Himantoglossum include many of Eurasia's most spectacular orchids, producing substantial spikes of showy flowers. However, until recently the genus had received only limited, and entirely traditional, systematic study. The aim of the current work was to provide a more robust molecular phylogeny in order to better understand the evolutionary relationships among species of particular conservation concern.
  
  
  METHODS
  All putative species of Himantoglossum s.l. were sampled across its geographical range. A large subsample of the 153 populations studied contributed to an initial survey of nuclear ribosomal internal transcribed spacer (nrITS) ribotypes. Smaller subsets were then sequenced for four plastid regions and the first intron of the low-copy-number nuclear gene LEAFY. Rooted using Steveniella as outgroup, phylogenetic trees were generated using parsimony and Bayesian methods from each of the three datasets, supplemented with a ribotype network.
  
  
  RESULTS
  The resulting trees collectively determined the order of branching of the early divergent taxa as Himantoglossum comperianum > H. robertianum group > H. formosum, events that also involved significant morphological divergence. Relaxed molecular clock dating suggested that these divergences preceded the Pleistocene glaciations (the origin of the H. robertianum group may have coincided with the Messinian salinity crisis) and occurred in Asia Minor and/or the Caucasus. Among more controversial taxa of the H. hircinum-jankae clade, which are only subtly morphologically divergent, topological resolution was poorer and topological incongruence between datasets was consequently greater.
  
  
  CONCLUSIONS
  Plastid sequence divergence is broadly consistent with prior, morphologically circumscribed taxa and indicates a division between H. hircinum-adriaticum to the west of the Carpathians and H. jankae-caprinum (plus local endemics) to the east, a distinction also suggested by nrITS ribotypes. LEAFY phylogenies are less congruent with prior taxonomic arrangements and include one likely example of paralogy. Himantoglossum metlesicsianum fully merits its IUCN Endangered status. Potentially significant genetic variation was detected within Steveniella satyrioides, H. robertianum and H. hircinum. However, confident circumscription of the more derived species of Himantoglossum s.s., including local endemics of hybrid origin, must await future morphometric and population-genetic analyses.
authors.affiliation: MTA-ELTE-MTM Ecology Research Group, Pázmány P. sétány 1/C, Budapest, 1117, Hungary Department of Botany, University of Debrecen, Egyetem ter 1., Debrecen, 4032, Hungary sramko.gabor@science.unideb.hu.
authors.forename: Gábor
authors.initials: G
authors.lastname: Sramkó
authors.affiliation: Department of Botany, University of Debrecen, Egyetem ter 1., Debrecen, 4032, Hungary.
authors.forename: Molnár V
authors.initials: MV
authors.lastname: Attila
authors.affiliation: School of Biological Sciences, University of Reading, Reading RG6 6AS, UK.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Hawkins
authors.affiliation: Jodrell Laboratory, Royal Botanical Gardens Kew, Richmond, Surrey TW9 3DS, UK.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Bateman
mesh_terms: D001208:Asia; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005060:Europe; D019143:Evolution, Molecular; D014644:Genetic Variation; D018745:Genome, Plant; D005843:Geography; D029595:Orchidaceae / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D021521:Ribotyping; D013045:Species Specificity
chemical_list: D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer; D010940:Plant Proteins
keywords: Dating; Himantoglossum s.l.; LEAFY; Orchidaceae; evolution; hybridization; incomplete lineage sorting; internal transcribed spacer; molecular phylogeny; molecular phylogeography; nrITS; orchid; topological incongruence