Costa 2015 (Conference Paper) Pitcairnioideae

Morphological characters in Bromeliad phylogenies: why use them?

Author(s):—A.F. Costa in Benko-Iseppon, A.M.; Alves, M. & Louzada, R. (2015) An overview and abstracts of the First World Congress on Bromeliaceae Evolution. Rodriguésia 66(2): A1-A66.

Publication:— (2015).

Abstract:—The proposition of phylogenetic hypotheses based on molecular data brought a new paradigm for the evolution ofliving organisms at all taxonomic levels. In Bromeliaceae, since the first hypotheses were proposed, while usingone or a few plastid markers, the monophyly of the family and the polyphyly of Pitcairnioideae were highlighted.Due to the large number of characters generated by such a set of data, unambiguous coding, speed and ease ofaccess them, the external nodes and the major lineages could be identified. More recently, nuclear markers havebrought more resolution to the trees. On the other hand, morphological data have been little used for such reconstruction mainly due to high levels of homoplasies, low resolution and low levels of support of the branches.However, molecular data have lower resolution in more external nodes of the trees due to lower nucleotidesubstitution rates. In this sense, the morphological data have shown to be powerful in more closely related taxa,both isolated or when combined with molecular data. This is evidenced in the phylogenies proposed for differentgenera of Bromeliaceae, where data from the external morphology (and in some cases leaf anatomy) were used,especially in Lymania, Pitcairnia, Puya, Quesnelia and Vriesea. Moreover, the inclusion of morphological datain the matrices allows the identification of synapomorphies that can be used in classification.

Keywords:—Morphological Data; Phylogeny; Classification.