Gostel, Morgan R. , Plunkett, Gregory M. , Lowry II, Porter P. .
Evolutionary relationships in African-Malagasy Schefflera: Exploring phylogenetic and biogeographic connections.
The genus Schefflera (900+ species) comprises nearly half of the species diversity in Araliaceae, but recent phylogenetic analyses based on molecular data have uncovered extensive polyphyly in the genus, and five major clades of Schefflera have been identified, each exhibiting a high degree of geographic structuring. One of these clades includes all representatives of Schefflera from Africa and Madagascar, but only a fraction of the 47 species from this region had been sampled. The present study employs an expanded sample of both taxa and molecular markers to explore further the patterns of phylogenetic and biogeographic relationships among these species. Nuclear ITS and ETS data confirm earlier suggestions that all species of Schefflera sampled from Africa and Madagascar are monophyletic. Within this lineage, there are two large subclades, largely corresponding to earlier concepts of the segregate genera Neocussonia (best developed in Madagascar) and Astropanax (most diverse in continental Africa). Early indications from plastid sequence data (ndhF-rpl32) appear consistent with these results as well. Previous hypotheses regarding biogeographic connections among other elements of the Indian Ocean Basin flora demonstrate evidence of various patterns of evolution. Many Malagasy species show a high degree of similarity to Western Pacific groups, this however does not seem to be the case within the African-Malagasy Schefflera.
Log in to add this item to your schedule
1 - Virginia Commonwealth University, Department of Biology, 1000 West Cary St., Room 126, Richmond, VA, 23284-2012, USA
2 - New York Botanical Garden, Cullman Program for Molecular Systematics, 209 Southern Blvd., Bronx, NY, 10458, USA
3 - Missouri Botanical Garden, Po Box 299, St Louis, Missouri, 63166-0299, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Maybird/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 2:30 PM