Chalcone synthase variation and phylogenetic relationships in Dactylorhiza (Orchidaceae)

Different authors have demonstrated the usefulness of single-copy nuclear genes in unravelling the evolution of polyploid species' complexes. We used the chalcone synthase gene family to analyse relationships among several Dactylorhiza species belonging to the main diploid and tetraploid lineages of this genus and to evaluate relationships between Dactylorhiza and other orchid genera that traditionally have been considered to be closely related. Overall, 59 sequences from 19 taxa were analysed using parsimony and Bayesian inference. In our results, we recover a sister relationship between Dactylorhiza and Gymnadenia. In addition, our results support the idea that genera Coeloglossum and Dactylorhiza should be merged into one taxonomic entity. Finally, we add some information on the origin of allotetraploid Dactylorhiza taxa, such as D. praetermissa and D. elata. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 155–165.