Systematics Section / ASPT
Miles, Nicholas W. , Mast, Austin .
Resolving relationships in Dryandra (Proteaceae), a large plant lineage endemic to Australia’s isolated southwest corner.
THE Australian genus Dryandra (93 spp.) is composed of shrubs from dry, open, fire-swept environments in Australia’s isolated southwest corner – a global biodiversity hotspot. Prior molecular phylogenetic work demonstrated that the 8 sampled species of Dryandra represent a monophyletic group that is nested in the more widespread genus Banksia (80 spp.). Dryandra differs from Banksia principally in its possession of a capitate inflorescence, rather than an inflorescence with an elongate axis. We infer a phylogeny for the group with sequences of six chloroplast (trnL/F spacer, trnL and rpl16 introns, and matK, atpB, and ndhF genes) and three nuclear (PHYA and both loci of waxy) DNA regions (>10 kb of aligned sequence data) from a quarter of the species in Dryandra and close relatives in Banksia. This sampling represents all 3 subgenera and 23 of the 24 series of Dryandra, and it is the most complete sampling of the genus for phylogenetic inference to date. In the inferred cpDNA phylogeny, Dryandra subulata, representing a monotypic series with a convex inflorescence, is not most closely related to the remaining sampled species of Dryandra. Instead, it is most closely related to a small group of banksias that represent a second (independent) reduction in inflorescence axis size. There is little resolution within the clade of other sampled dryandras. This is due to low levels of genetic variation, on par with, or in some cases less than, that seen within groups recognized at the rank of series in Banksia. We infer the mean age of the Dryandra crown group to be about a third of the age of the Banksia+Dryandra crown group, and we explore the sensitivity of this result to the subsets of DNA data used for the inference.[c.e.:srb]
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Mast Faculty Web Page
1 - Florida State University, Department of Biological Sciences, Tallahasse, Florida, 32306-1100, USA
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM