Molecular phylogenetics of Cymbidium (Orchidaceae: Maxillarieae): sequence data from internal transcribed spacers (ITS) of nuclear ribosomal DNA and plastid matK

Abstract

Nuclear ribosomal spacer (ITS) DNA and plastid matK sequence data were collected for 34 accessions of Cymbidium and six outgroups from Maxillarieae to evaluate infrageneric classification and phylogenetic relationships. The levels of sequence variation found were higher than in other Epidendroideae studied to date, and phylogenetic relationships obtained moderate to high bootstrap support. Both ITS and matK data sets were in overall agreement, and although two or three subgenera can potentially be defined within the genus, there was little molecular support for section delimitation because the level of variation was too low. Phylogenetic relationships indicate a southeastern Asian origin for the genus.