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Hannah Riden

Allan Wilson Centre for Molecular Ecology and Evolution,
Massey University,
Palmerston North
Webpage: http://www.massey.ac.nz/~hriden/

Dr. Peter Lockhart (AWCMEE),
Dr. Mark Large (Unitec)
Dr. Ilse Breitwieser (Landcare)

My PhD is based on characterising adaptive radiations in New Zealand plant groups, in particular that of willowherbs (the genus Epilobium, in the family Onagraceae). This group is fascinating, but not very popular with many taxonomists due to the very close similarity of many of the species (making identification rather problematic, to say the least!).

NZ Willowherbs

Little is known about how the species relate to each other, or to the willowherb species found in other temperate regions throughout the world (including Australia, North America, Europe and parts of South America). I hope to be able to use molecular tools such as DNA sequences to construct a species phylogeny of the New Zealand species, and add this to existing molecular data for willowherbs from other parts of the world.

A clear picture of how the species are related will allow us to answer a number of questions for example; where did the New Zealand group of willowherbs come from?; have willowherbs arrived in New Zealand more than once?; how recently did the New Zealand willowherbs diversify?; which New Zealand species are the most distinct genetically?; is there evidence for hybridisation being an important mechanism for speciation in this group? I also plan to study the population genetic structure of the New Zealand willowherbs using molecular markers such as ISSR, AFLP and microsatellites. This will enable us to ascertain whether there is any geographic structure in the different species, for instance whether populations from the north of the South Island are markedly different to populations from the south, as has been found in buttercups (genus Ranunculus, in the family Ranunculaceae). This may indicate a range contraction during the last ice-age to areas free of ice, or glacial refugia.