Poster Presentation Society for Molecular Biology and Evolution Conference 2016

A molecular investigation of the relationships of karaka (Corynocarpus laevigatus). (#653)

Lara Shepherd 1 , Robin Atherton 2 , Peter de Lange 3 , David Chagne 4 , Nick Roskruge 2 , Peter Lockhart 2
  1. Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand
  2. Massey University, Palmerston North
  3. Department of Conservation , Auckland
  4. Plant and Food Research, Palmerston North

Corynocarpus laevigatus (karaka, kōpi) is a small tree whose kernels provided an important food source for New Zealand Māori before European settlement. Much of the contemporary distribution of karaka, including its presence on the distant Kermadec and Chatham Island groups, is considered to have resulted from translocations as part of its cultivation.

We examined the patterns of pre-European translocation of karaka using sequences from two nuclear loci and SNPs developed from whole chloroplast DNA sequences screened with high resolution melting (HRM). Our results indicated low levels of genetic diversity in karaka at both chloroplast and nuclear loci. However, our New Zealand-wide sampling revealed a reduction in genetic diversity in the translocated populations compared to the natural range in northern New Zealand. The distinctiveness of specimens from the Three Kings Islands excluded this region as the source population for translocated karaka. For the remaining populations the lack of genetic diversity, combined with low levels of genetic structuring, prevented more precise identification of the source of translocated karaka.