Solanum Phylogeny Inferred from Chloroplast Dna Sequence Data

A data set derived from gene sequences of ndhF is used to deduce phylogenetic relationships among the subgenera of Solanum, among related genera of the tribe Solaneae, and within selected Solanum clades. Complete ndhF sequences were obtained for 12 species of Solanum, representing five of the seven subgenera. ndhF sequences also were obtained from species of Capsicum, Cyphomandra, Datura, Jaltomata, Lycopersicon, Nicotiana, and Physalis. Results of a parsimony analysis of these data indicate that the Solanum species form a monophyletic clade with Capsicum rather weakly supported as the sister group. LycojJersicon and Cyphomandra are included within the Solanum clade. Three to four clades can be identified within Solanum. The subgenera Minon and Potaloe are probably not monophyletic as currently defined. Solanum wendlandii, a species with recurved prickles but no stellate hairs, does not belong with the other spiny solanums in subgenus Leptosternonurn. These results cast doubt on the utility of traditional char~lcters such as anther shape and hair morphology in defining high-level infrageneric groups in Solanum.