Abstract Detail

Systematics Section

Iles, Will [1], Sokoloff, Dmitry D [2], Rudall, Paula J. [3], Remizowa, Margarita V [2], Graham, Sean W. [4].

Evolutionary implications of Hydatellaceae phylogeny.

Hydatellaceae, a small (mostly) Australian family of highly reduced aquatics, are sister to the water lilies (Cabombaceae and Nymphaeaceae), and emerge from a deep split near the base of angiosperm phylogeny. Recent interest in the family has led to a flurry of research on their reproductive and structural biology. Building on earlier results we use DNA sequence data from four plastid gene regions, and taxon sampling encompassing the known diversity of the family, to infer a robustly supported phylogeny. As previously reported, the species form three well supported clades that can be broadly delineated by their geography. A majority of the species appear to be monophyletic according to plastid data, an exception being the south-western Trithuria bibracteata, within which the more geographically widespread T. submersa seems to be nested. We also sample 17-plastid genes from exemplar taxa from each of the three major clades to address the previously unresolved rooting of the family. Our results show clearly that the northern Australian clade is sister to the two southern clades. We also perform character reconstructions using parsimony and maximum likelihood on dioecy and associated traits, as well as on life history, fruit and seed characters. Dioecious species appear to be scattered evenly throughout the tree, implying frequent transitions in sexual systems. We also use a relaxed-dating method to attempt to date the origin of the crown clade and its divergence from the main line of water lilies.

Broader Impacts:

1 - University of British Columbia, Department of Botany, 3529-6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
2 - Moscow State University, Department of Higher Plants, Biological Faculty, 119992, Moscow, Russia
3 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Molecular Systematics Section, Richmond, Surrey, TW9 3DS, United Kingdom
4 - University of British Columbia, UBC Botanical Garden and Certre for Plant Research, 6804 SW Marine Drive, Vancouver, BC, V6T 1Z4, Canada

Keywords:
Basal angiosperms
character evolution
sexual system
molecular dating.

Presentation Type: Oral Paper:Papers for Sections
Session: 27
Location: 552A/Convention Center
Date: Tuesday, August 3rd, 2010
Time: 10:00 AM
Number: 27008
Abstract ID:770