Molecular Phylogenetics of Galeandra (Orchidaceae: Catasetinae) Based on Plastid and Nuclear DNA Sequences

Abstract Galeandra is a neotropical genus with its center of diversity in the Amazon region. It comprises approximately 18 species of epiphytic and terrestrial herbs that are easily recognizable by their funnel-shaped labellum. We examined the phylogenetic relationships among species of Galeandra inferred from nucleotide sequences from three plastid (psbA-trnH, rpoB-trnC, and trnS-trnG) and two nuclear (ITS and ETS) DNA regions. The five data matrices were analyzed individually and in combined analyses using parsimony and maximum likelihood. We found that the epiphytic species G. devoniana is sister to the remainder of the genus, and that the other species form two groups, one consisting of epiphytic species and the other composed of terrestrial species. Adaptation to the terrestrial environment from a probable epiphytic ancestor was of great importance in the evolution of Galeandra. The relationships found in this study do not support previous infrageneric classifications.Abstract Galeandra is a neotropical genus with its center of diversity in the Amazon region. It comprises approximately 18 species of epiphytic and terrestrial herbs that are easily recognizable by their funnel-shaped labellum. We examined the phylogenetic relationships among species of Galeandra inferred from nucleotide sequences from three plastid (psbA-trnH, rpoB-trnC, and trnS-trnG) and two nuclear (ITS and ETS) DNA regions. The five data matrices were analyzed individually and in combined analyses using parsimony and maximum likelihood. We found that the epiphytic species G. devoniana is sister to the remainder of the genus, and that the other species form two groups, one consisting of epiphytic species and the other composed of terrestrial species. Adaptation to the terrestrial environment from a probable epiphytic ancestor was of great importance in the evolution of Galeandra. The relationships found in this study do not support previous infrageneric classifications.