@ARTICLE{TreeBASE2Ref17098, author = {Vanessa Plana and Richard M. Bateman and J. J. F. E. d. Wilde}, title = {Morphological and molecular cladistic analysis of the fleshy-fruited African sections of Begonia}, year = {2005}, keywords = {}, doi = {}, url = {}, pmid = {}, journal = {Systematic Botany}, volume = {}, number = {}, pages = {}, abstract = {The 26% of African Begonia species that possess distinctive dehiscent or indehiscent, non-winged fleshy fruits (59% of the world total of fleshy-fruited begonias) are traditionally assigned to four sections; 73% of these species occur in section Tetraphila, concentrated in Central and West Africa. All 34 species of sections Baccabegonia, Squamibegonia and Tetraphila, plus two outgroups, were coded into an initially broad morphological matrix that was eventually reduced to 27 bistate, multistate, and meristic characters well distributed across the body of the plant. A representative subset of 23 ingroup and two outgroup species was also analyzed for DNA sequences of nrITS and the plastid trnL intron. Parsimony trees generated from ITS and trnL showed good congruence, and although each was statistically incongruent with the morphology-only trees, the areas of incongruence were poorly supported, so the three matrices were later combined to maximize confidence in the ensuing interpretations. The morphology-only analysis demonstrated that eliminating polymorphic characters greatly reduced resolution, also suggesting that earlier culling of potentially useful but problematic characters may have been overly rigorous. All three sets of trees identified as unequivocally monophyletic the fleshy-fruited African begonias, sections Baccabegonia and Squamibegonia (reliably placed as sisters), and the core members of section Tetraphila. The main sources of instability were B. longipetiolata and B. loranthoides, which were placed by morphology within core Tetraphila, by trnL as sisters to core Tetraphila, and by ITS (and the combined analysis) as sisters to sections Baccabegonia plus Squamibegonia. As this clade is not readily diagnosed by morphology, a pragmatic decision was taken to continue to recognize a putatively paraphyletic traditional circumscription of section Tetraphila. The combined analysis revealed moderately to weakly supported groups within core Tetraphila that share only a few morphological synapomorphies and have some geographical and/or ecological cohesion; they reflect a bona fide, non-recent evolutionary radiation. Comparison with several other morphological cladistic analyses of Begonia allows generalizations regarding character coding, and shows that the strongest phylogenetic signal is provided by floral characters traditionally employed in the taxonomy of Begonia. Evolutionary patterns in the group are interpreted in terms of pollinatiom and dispersal syndromes (notably endozoochory) and ecological shifts. Island-based giantism and polyploidy are also evident, as is a strong biogeographic overprint.} }

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