Department of Botany,
PO Box 56,
Dr. David Orlovich, Department of Botany, Otago University
Dr. Janice Lord, Department of Botany, Otago University
Dr. Bill Lee, Landcare Dunedin
In collaboration with:
Dr Shane Wright, Auckland University, School of Biological Sciences.
Dr Richard Gardner, Auckland University, School of Biological Sciences.
Stephan Wichman Auckland University, School of Biological Sciences.
Although the Rubiaceae is a characteristically pantropical family, it is represented in southern temperate regions primarily by the austral tribe, Anthospermeae. The three subtribes that constitute this tribe have relatively disjunct distributions, with the Coprosminae encompassing the Melasianan-South Pacific range of the Anthospermeae. Of the five genera in the Coprosminae, the two main genera, Coprosma and Nertera, both have their primary centers of diversity in New Zealand. Long distance dispersal accounts for their subsequent radiation into Pacific islands and montane regions outside of New Zealand. Coprosma is one of the most characteristic and speciose genera in New Zealand, containing over half of the total of c.100 species, and most of these are endemics. Almost every terrestrial habitat harbours at least one species, and the genus is renowned for a predominance of indistinguishable, divaricate, shrubby taxa. The lack of clear diagnostic characters in Coprosma has
earned it the both the chagrin of field ecologists and a long history of taxonomic inquiry in New Zealand.
My PhD topical has centered on both the evolution of fruit traits in the Coprosminae, particularly exploring both the transition from dry to fleshy fruit in the subtribe, and the evolution of fruit colour in Coprosma and Nertera.
Within the dry-fruited Anthospermeae, fleshy fruit has arisen solely in the Coprosminae. Coprosma is of particular interest in that it exhibits fruit colours that range from red and orange to blue and white. This is in contrast to its' sister genus, Nertera, where fruit colour is almost uniformly orange. In order to track changes in fruit traits, I have used sequences from the ITS and ETS regions of nrDNA to infer phylogenetic relationships within the subtribe and genus. From this, I hope to find some suggestion as to how labile are fruit dispersal traits in the Coprosminae. A phylogeny of Coprosma would contribute to understanding New Zealand's flora.