Phylogenetic relationships within the blueberry tribe (Vaccinieae, Ericaceae) based on sequence data from MATK and nuclear ribosomal ITS regions, with comments on the placement of Satyria

Abstract

The blueberry tribe (Vaccinieae) is a large and morphologically diverse group that is widespread in the temperate and tropical zones of most continents. The greatest species diversity is in the tropics, where Vaccinieae are a major component of montane cloud forests. Generic limits are poorly understood, and many of the characters traditionally used fail to adequately distinguish among taxa. This study analyzed sequence data from the chloroplast matK gene and the nrITS region for 93 species of Vaccinieae, representing 28 genera, and 16 sections (of the ∼33 currently recognized) of Vaccinium. Results indicated that, in general, traditional generic circumscriptions were not corroborated, but several well-supported clades were found: an Andean clade (including at least some members of 18 of the 23 Neotropical genera sampled), a Meso-American/Caribbean clade, an East Malesian clade (including the Old World taxa Paphia and Dimorphanthera), an Agapetes clade comprised of some Asian Vaccinium and Agapetes, and a Bracteata-Oarianthe clade (Vaccinium spp.). This study is the first to address phylogenetic relationships among members of Vaccinieae on a worldwide basis and the results indicate that the large genus Vaccinium is not monophyletic, but likely represents a grade group out of which several more specialized clades evolved.