title: Phylogenetic relationships of the mycoheterotrophic genus Voyria and the implications for the biogeographic history of Gentianaceae.
abstract: OBJECTIVE
  The angiosperm family Gentianaceae comprises over 1700 species in 91 genera. Gentianaceae are distributed worldwide, but most species occur in temperate zones. Phylogenetic studies demonstrate that the family consists of six monophyletic tribes. However, the phylogenetic position of the mycoheterotrophic genus Voyria, with a remarkable trans-Atlantic distribution, remained unknown.
  
  
  METHODS
  We used nuclear ITS and 18S rDNA and mitochondrial apt1 and matR data to infer the phylogenetic position of Voyria in Gentianaceae. In addition, with Bayesian relaxed molecular clock analyses we obtained age estimates for the diversification of Voyria and Gentianaceae in general and used these results to reconstruct the ancestral areas associated with the early diversification events in Gentianaceae.
  
  
  RESULTS
  Our results demonstrate that Voyria is an early diverging lineage within Gentianaceae with no close relationships to other mycoheterotrophic Gentianaceae lineages. Voyria originated in the neotropics during the Early Eocene but only reached its current transoceanic distribution around the end of the Oligocene. The neotropics were an important area for the early diversification events in Gentianaceae, most of which occurred during the Eocene.
  
  
  CONCLUSIONS
  Voyria is an old, phylogenetically isolated lineage within Gentianaceae, and the current distribution of the genus is indicative of the ancestral area in which the early diversification events of Gentianaceae occurred. In parallel with many other pantropical families, our results suggest that migration of tropical taxa through Laurasia during the Early Eocene has played an important role in shaping the current global distribution of Gentianaceae.
authors.affiliation: Naturalis Biodiversity Center, Leiden University, P.O. Box 9517, Leiden, Netherlands. vincent.merckx@naturalis.nl
authors.forename: Vincent S F T
authors.initials: VS
authors.lastname: Merckx
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kissling
authors.forename: Heiko
authors.initials: H
authors.lastname: Hentrich
authors.forename: Steven B
authors.initials: SB
authors.lastname: Janssens
authors.forename: Constantijn B
authors.initials: CB
authors.lastname: Mennes
authors.forename: Chelsea D
authors.initials: CD
authors.lastname: Specht
authors.forename: Erik F
authors.initials: EF
authors.lastname: Smets
mesh_terms: D001499:Bayes Theorem; D021903:DNA, Ribosomal Spacer / Q000737:chemistry; D029965:Gentianaceae / Q000235:genetics*; D010802:Phylogeny; D058974:Phylogeography
chemical_list: D021903:DNA, Ribosomal Spacer