Monophyly and Phylogenetic Relationships in <I>Lymania</I> (Bromeliaceae: Bromelioideae) Based on Morphology and Chloroplast DNA Sequences

Abstract

A cladistic analysis of Lymania was conducted using morphology and sequences from three chloroplast DNA regions: the matK coding region and the psbA-trnH and trnL-trnF intergenic spacers. The monophyly of the genus and the phylogenetic relationships among related genera were examined. Of the nine Lymania species, eight are endemic to southern Bahia, Brazil. Lymania is the first genus in Bromeliaceae subfamily Bromelioideae to be subjected to a combined morphological and molecular analysis. The genera of Bromelioideae have been particularly difficult to classify and there has been disagreement about their interrelationships and monophyly. Morphological data show better resolution than molecular data alone. The partition homogeneity test supported a combined analysis of the two data sets, yielding a single most parsimonious tree. In the combined analysis, monophyly of Lymania is moderately supported, and the genus is closely related to species of Aechmea subg. Lamprococcus and subg. subg. Ortigiesia. The morphological distinctiveness coupled with low molecular divergence indicates relatively recent and rapid speciation within Lymania. The combined analysis of morphological and molecular data as done in this study provides a framework for future research on other Bromelioideae genera that could foster better taxonomic rearrangements.