GARCIA, VICENTE F.* and RICHARD G. OLMSTEAD. Dept. of Botany, University of Washington, Seattle, WA 98195. - Phylogenetic relationships of the Australian tribe Anthocercideae (Solanaceae) based on chloroplast DNA sequences.
Tribe Anthocercideae (Solanaceae) consists of seven genera with 31
species endemic to Australia. Past classification of the group
resulted in the placement of the seven genera into several tribes. The
group was later unified into tribe Anthocercideae, and is now placed
as sister to Nicotiana, but phylogenetic work on Anthocercideae
remains limited. A more extensive study encompassing all genera was
needed to discover lower level relationships within the tribe. A
phylogeny of the group was created by studying variation in two
chloroplast DNA regions, ndhF and trnL-trnF. This
phylogeny allowed us to look at floral character evolution and rates
of gene evolution. Tribe Anthocercideae, without genus
Symonanthus forms a well-supported, monophyletic group. Each
genus in the tribe also forms a monophyletic group, except for
Cyphanthera, which appears to be paraphyletic.
Symonanthus is found to be more closely related to
Nicotiana than to the rest of the tribe. It was found that
bilocular stamens is the ancestral condition, and unilocular stamens
are evolutionarily derived. Floral character evolution and rates of
gene evolution will be discussed in more detail.
Key words: Anthocercideae, Australia, floral evolution, Solanaceae