Nuclear rDNA ITS sequence data used to construct the first phylogeny of Vanguerieae (Rubiaceae)

Abstract.

 The morphologically homogenous tribe Vanguerieae was investigated phylogenetically using sequence data from the Internal Transcribed Spacer (ITS) region in the nuclear ribosomal DNA. Sequences from 41 Vanguerieae species representing 19 genera were produced, and a parsimony analysis was performed. The phylogenetic analysis has several clades with strong support, among which three new informal groups are discussed, i.e. the Vangueria group, the Fadogia-Rytigynia group and the Spiny group. Also found monophyletic with strong support are Multidentia, Keetia, Lagynias, and Pyrostria. Canthium and Rytigynia are revealed as polyphyletic; Vangueria, Tapiphyllum, and Fadogia are paraphyletic. Results from this first phylogenetic analysis of the tribe clearly demonstrate a need for new circumscriptions of several genera. Morphological characters are discussed and putative synapomorphies are mentioned. Jackknife, bootstrap, and Bremer support are calculated and differences found in support are discussed.