Hong-Wa, Cynthia , Besnard, Guillaume .
Phylogeny of the genus Noronhia (Oleaceae) and relatives: inferences from nuclear and chloroplast sequence data.
Noronhia (Oleaceae) currently comprises 45 species, all of which are endemic to the Malagasy floristic region (43 species in Madagascar and 2 in the Comoro Islands). Noronhia is a morphologically and ecologically very diverse group, whose close relationship with the three Malagasy species of Chionanthus (previously included in Linociera) has long been suggested. Recent molecular phylogenies indicate unresolved relationships within subtribe Oleinae, which includes Noronhia, Chionanthus, Olea and nine other extant and extinct genera. In this study, the phylogenetic utility of chloroplast (trnLF, trnTL, trnSG, matK) and nuclear (nrITS, Tpi) DNA markers in identifying relationships within subtribe Oleinae is assessed, the monophyly of Noronhia is investigated, and relationships among its species are examined. Nine of the twelve genera within Oleinae were sampled and preliminary results show improved resolution of phylogenetic relationships among them. Noronhia and Chionanthus from the Malagasy floristic region form a monophyletic group, sister to an African clade of Chionanthus (formerly Linociera). A near-complete species-level phylogeny of Noronhia shows an unexpected lack of genetic variation among species to allow meaningful reconstruction of infra-generic relationships, and suggests a rapid and/or recent radiation within Madagascar or slow molecular evolution. Results also suggest several cases of para- or polyphyly within Oleinae; these, with previous studies, call for a comprehensive taxonomic revision within the family.
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1 - University of Missouri-St. Louis, Biology, One University Blvd, St. Louis, MO, 63121, USA
2 - CNRS UMR 5174-Université Paul Sabatier, Laboratoire EDB, 118 Rue de Narbonne, Toulouse, 31062, France
Malagasy Floristic Region.
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 1:30 PM