Systematics Section / ASPT
Karaman, Vesna , Urbatsch, Lowell .
Phylogeny of Hinterhuberinae (Astereae: Asteraceae) based on ITS and ETS nrDNA sequence data.
Subtribe Hinterhuberinae includes approximately 30 genera growing in high elevations of southern Africa, Madagascar, Australiasia, and Central and South America with two genera extending northward into Mexico. The group is characterized by entire and coriaceous leaves with revolute margins, corymboid capitulescence, epaleate or paleate receptacle, ray florets with well developed or reduced and variously modified ligules, and bisexual disc florets sometimes with sterile ovaries. Dioecy is present in the genus Aztecaster. Recent ITS and ETS-based phylogenies that included several representatives of the subtribe Hinterhuberinae confirmed its basal position in the tribe Astereae, but did not support its monophyly. To evaluate the delimitation of the genera within the subtribe, and elucidate its relationship within tribe Astereae, we conducted a phylogenetic analysis of the ITS and ETS nrDNA. We included at least one species of each genus from informally recognized groups within the subtribe: Chiliotrichum, Celmisia, Olearia, Remya, and Madagaster, with more extensive sampling of Novenia and Hinterhubera groups. At least two representatives were sampled from primarily Southern Hemisphere subtribes: Felicinae, Grangeinae, Lageniferinae, Podocominae, Asterinae, Baccharedinae and Brachyscominae. Felicia and Amellus were designated as outgroup. The tree topologies for ETS and ITS datasets show overall congruence. The Chiliotrichum group (in part) is in the basal clade together with Celmisia and Madagaster groups. Novenia is most closely related to Oritrophium, and both are in the basal clade. The Hinterhubera group is polyphyletic, being placed in a derived and partially resolved Southern Hemisphere grade with Guynesomia and Diplostephium (from the Chiliotrichum group), Remya and Olearia (in part) and other sampled subtribes. Sequence data suggest an independent development of dioecy in Aztecaster and Baccharedinae. Our data support the hypothesis that the most primitive members of the subtribe are present in Madagascar, South America and Australasia, a sister to the most basal clade containing Commidendron species.
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1 - Louisiana State University, Department of Biological Sciences, 107 Life Sciences Bldg, Baton Rouge, Louisiana, 70803, USA
2 - Louisiana State University, Department of Biological Sciences, 202 Life Sciences Building, Baton Rouge, Louisiana, 70803-1705, USA
Presentation Type: Oral Paper
Date: Wednesday, August 17th, 2005
Time: 9:30 AM