First molecular phylogeny of the pantropical genus Dalbergia: implications for infrageneric circumscription and biogeography

Abstract

The genus Dalbergia with c. 250 species has a pantropical distribution. In spite of the high economic and ecological value of the genus, it has not yet been the focus of a species level phylogenetic study. We utilized ITS nuclear sequence data and included 64 Dalbergia species representative of its entire geographic range to provide a first phylogenetic framework of the genus to evaluate previous infrageneric classifications based on morphological data. The phylogenetic analyses performed suggest that Dalbergia is monophyletic and that it probably originated in the New World. Several clades corresponding to sections of these previous classifications are revealed. Taking into account that there is not a complete correlation between geography and phylogeny, and the estimation that the Dalbergia stem and crown clades are 40.4–43.3 mya and 3.8–12.7 mya, respectively, it is plausible that several long distance dispersal events underlie the pantropical distribution of the genus.