Systematics Section / ASPT
Chandler, GT , Plunkett, GM , Pinney, SM .
A beginners guide to Pittosporaceae: a first molecular phylogeny.
Pittosporaceae are a small family of flowering plants, with nine genera and about 200 to 240 species. The generic diversity of Pittosporaceae is almost exclusively restricted to Australia, with only Pittosporum found in other parts of the world. Of the few phylogenetic studies on Pittosporaceae, all have been based exclusively on morphological characters. Unfortunately, morphological characters in Pittosporaceae are complicated by an abundance of phenotypic plasticity. In addition, considerable morphological variation can be expressed within individual plants, especially at different ages (for example, juvenile versus adult foliage in Bursaria). To date, no intergeneric studies of Pittosporaceae have been performed based on molecular data. In this study, two molecular markers were investigated for phylogenetic utility in the family, ITS from nrDNA and the trnL-trnF intergenic spacer from cpDNA. Representatives from all nine genera of Pittosporaceae were sequenced to test relationships suggested by the recent study of morphology, analyzed using maximum parsimony and maximum likelihood methods. Outgroups were selected from the Myodocarpus group (Apiales) based on recent molecular data. Our data suggest that Pittosporum is monophyletic with the inclusion of Citriobatus and the exclusion of the new genus Auranticarpa, which is more closely related to Bursaria and Rhytidosporum. Sollya should be included in Billardiera, and Rhytidosporum may be re-established as a distinct genus. Billardiera (including Sollya), Marianthus, Bentleya and Cheiranthera have uncertain relationships in our data, requiring further work to establish their inter-relationships. In all major respects, these data support the recent taxonomic revisions based on morphology, and more broadly agree with hypotheses of an Australian origin for the family.
1 - University of North Carolina at Wilmington, Biological Sciences, 601 S. College Rd, Wilmington, North Carolina, 28403-5915, USA
2 - Virginia Commonwealth University, Department of Biology, P.O. Box 842012, Richmond, Virginia, 23284-2012, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 12:15 PM