Molecular evidence for the phylogenetic position of Takhtajania in the Winteraceae: Inference from nuclear ribosomal and chloroplast gene spacer sequences

The nucleotide sequences of the internal transcribed spacers (ITS 1 and ITS 2) and 5.8S coding region of nuclear ribosomal DNA, as well as the non-coding trnL-trnF spacer regions of the chloroplast DNA, were determined and analyzed to estimate the phylogenetic position of Takhtajania perrieri (Capuron) Baranova & J.-F. Leroy within the Winteraceae. Using representatives of each genus of Canellaceae as outgroups (Canella, Capsicodendron, Cinnamodendron, Cinnamosma, Pleodendron, and Warburgia), bath maximum parsimony and maximum likelihood analyses place Takhtajania in a basal position sister to the remainder of the Winteraceae. Although the overall topology within the Winteraceae was mostly congruent between nuclear and chloroplast data sets, the trnL-trnF data resulted in lower support values in comparison to the ITS data, and failed to resolve basal relationships in the family, yielding alternative equally parsimonious solutions. The combined nuclear/chloroplast data set resulted in a single tree identical to that generated by nuclear data alone, but demonstrated strengthened support for a basal branch lending to Takhtajania, as well as for the position of Tasmannia as the next branch within the family. Potentially conflicting signals from nuclear and chloroplast data indicate that further taxon sampling or additional sequence data may be required to infer infra-familial phylogenetic relationships for Canellaceae.