Colloquium: The flora of Madagascar: research needs and research progress
Vary, Laura , Buerki, Sven .
Breeding system evolution in the Malagasy Sapindaceae.
The Malagasy Sapindaceae are a large, diverse group, with 24 genera (nine endemic) and 97 described species. The endemic genera Molinaea, Neotina, Tina (Tribe Cupanieae) and Tinopsis (Tribe Schleichereae) have variable breeding systems, including both monoecy (separate sexed flowers on the same individual) and dioecy (separate sexed individuals). Previous preliminary phylogenetic work indicates that these four genera form a monophyletic group sister to a South American clade. Our goal was to produce a molecular phylogenetic tree to test hypotheses on the correlated evolution of breeding systems with fruit characteristics and habitat. We hypothesized that dioecy will be correlated with fleshy fruit and dry environments. We used seven chloroplast DNA markers (matK, rpoB, trnD-trnT intergeneric spacer (IGS), trnK-matK IGS, trnL intron, trnL-trnF IGS and trnS-trnG IGS) and three nuclear DNA markers (ITS region: ITS1, 5.8S and ITS2) to produce a total evidence tree using the Bayesian inference approach. Breeding systems, fruit characteristics and habitat were determined through observations of herbarium specimens and in the field. We found (i) strong support for Molinaea and Tina as monophyletic groups and Neotina nested within Tinopsis, (ii) that dioecy is significantly correlated with fleshy fruits, but not dry environments and (iii) monoecy is significantly correlated with capsular, dehiscent fruits. These data provide support for classic hypotheses on the correlated evolution of dioecy and fleshy fruits. Future studies should focus on testing hypotheses on the influence of inbreeding depression and outcrossing rates on the evolution of breeding systems in this group.
Log in to add this item to your schedule
1 - University of California, Irvine, Ecology and Evolutionary Biology, 321 Steinhaus Hall, Irvine, CA, 92697, USA
2 - Université de Neuchâtel, Institut de Botanique, Rue Emile-Argand 11, Neuchatel, CH-2009, Switzerland
Presentation Type: Symposium or Colloquium Presentation
Location: Blair B/Gage
Date: Tuesday, July 29th, 2008
Time: 10:45 AM