Abstract Detail

Systematics Section/ASPT

Kriebel, Ricardo [1], Reginato, Marcelo [2].

Floral evolution in the Melastomataceae: progress and challenges towards a floral phylomorphospace of the family.

The family of flowering plants Melastomataceae is one of the most diverse in the world with around 5000 species. Most species in the family have flowers with poricidal anthers that are buzz pollinated by some female bees. Some exceptions include pollination by hummingbirds, rodents, and generalist insects. Until now, no  attempt has been made to compare floral morphology between its major lineages using continuous variables and phylogenetic data. An attempt to do so was undertaken in this study, focusing on Neotropical lineages as a starting point. Floral measurements were taken from flowers preserved in spirit or from illustrations available in the literature. A total of 21 measurements per flower were taken for 600 species (ca. 20% of the neotropical diversity). Principal component analysis conducted to summarize these variables resulted in about 70% of the variation explained in the first three principal components (PCs). The first PC described overall flower size. The second PC included high loadings for ventral stamen appendage and stamen connective length of both the antepetalous and antesepalous stamens, and the third component included high loadings for dorsal stamen appendage length of both the antepetalous and antesepalous stamens, as well as for stigma width. The morphospace of the first 3 PCs showed structure congruent with major tribes within the family. In addition, a phylogeny of the family was built upon available published data. A Phylogenetic PCA was conducted with the taxa matching the phylogenetic tree (67% match; 400 tips). The scatter plot of the PPCA shows a similar morphospace to the one obtained with all the data. Phylomorphospaces and ancestral state reconstructions of flower shape and individual variables were used to visualize the data in a phylogenetic context. Although the morphometric data gathered for this preliminary study match the phylogeny well (strong phylogenetic signal for all variables), suggesting early divergence in flower morphology and floral conservatism, several instances of convergence were observed. The utility and limitations of this ongoing data set for testing hypothesis about floral evolution in the family is discussed with some examples.

1 - University of Wisconsin-Madison, Department of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458, USA

Keywords:
flower morphometrics
Melastomataceae
Phylogeny
Phylomorphospace.

Presentation Type: Oral Paper:Papers for Sections
Session: 14
Location: Cottonwoods North/Boise Centre
Date: Monday, July 28th, 2014
Time: 4:45 PM
Number: 14013
Abstract ID:668
Candidate for Awards:None