| Phylogenetic relationships among 58 species of Bromeliaceae are examined by comparative sequencing of the chloroplast locus ndhF. DNA amplification using the polymerase chain reaction and dideoxy sequencing were performed using 16 oligonucleotide primers, 11 of which were designed specifically for this study. Amplification and sequencing results indicate these primers are well-suited for use in comparative studies in other monocot families (e.g., Velloziaceae). Results from parsimony analysis of 30 sequences representing all subfamilies of Bromeliaceae support a sister group relationship for Bromelioideae and Pitcairnioideae, and resolve Tillandsioideae near the base of the family. Both Tillandsioideae and Bromelioideae are monophyletic, but alternative placements for Puya and Brocchinia indicate Pitcairnioideae is paraphyletic. Recognition of Brocchinia as a subfamily and the realignment of Puya with Bromelioideae are proposed. Analysis of sequences from 28 species representing all genera and seven of nine subgenera provided additional support for the monophyly of Tillandsioideae. ndhF sequences provide weak support for the inclusion of Catopsis and Glomeropitcairnia in Tillandsioideae. A clade containing the "core tillandsioids," i.e., Tillandsia, Vriesea, Guzmania and Mezobromelia, is more strongly supported, as are clades containing Catopsis and Vriesea subg. Vriesea sect. Xiphion. Tillandsia, Vriesea, and Guzmania, as well as all subgenera of Tillandsia and Vriesea for which at least two taxa are sampled (Allardtia, Anoplophytum, Tillandsia, and Vriesea), are resolved as paraphyletic. A close relationship is supported for Tillandsia and Guzmania, and Mezobromelia appears closely related to Vriesea subg. Vriesea sect. Xiphion. Poor resolution and week branch support for many clades in the ndhF trees suggests that information from more highly variable sequences or the combining of data will be required for a clearer understanding of phylogenetic relationships in Bromeliaceae. |
