Phylogenetic Relationships in Bromeliaceae Subfamily Bromelioideae based on Chloroplast DNA Sequence Data

Abstract—

Of the eight subfamilies currently recognized in Bromeliaceae, Bromelioideae is perhaps the most poorly understood. Generic circumscriptions are unclear, and an exceptionally diverse morphology coupled with an unusually low rate of sequence divergence within Bromeliaceae has made it difficult to resolve phylogenetic relationships within the subfamily. Although recent molecular studies have begun elucidating relationships among species in Bromeliaceae, most have not sampled deeply and/or broadly across Bromelioideae. The purpose of this study was to conduct a phylogenetic analysis within subfamily Bromelioideae using three chloroplast DNA regions (matK, psbA-trnH, and trnL-trnF), with the inclusion of multiple species from a broad sampling of bromelioid genera. Ochagavia, Deinacanthon, Fascicularia, Bromelia and Fernseea diverged relatively early in the history of the subfamily, with the remaining taxa being placed in a large and poorly resolved eubromelioid clade. Bromelia and Cryptanthus were found to be monophyletic, while 13 other genera were polyphyletic. Aechmea, the most morphologically diverse genus within the subfamily, was highly polyphyletic, with species distributed among 12 different lineages, with little support for subgeneric circumscriptions.