Identifying Host Species of Dactylanthus taylorii using DNA Barcoding

Abstract

The population of the endangered endemic holoparasitic plant, Dactylanthus taylorii Hook F. (Balanophoraceae), in Pureora Forest Park was selected as the trial population for developing a method to accurately identify host species using DNA barcoding methods. The marker used was psbA-trnH, and ten samples were able to be successfully identified using the protocol trialed. Of these samples, nine were identified as Pseudopanax arboreus, with one result of Podocarpus totara. The marker used (psbA-trnH) provided adequate levels of variation to discriminate between the host species sequenced in the pilot study. Further work will focus on refining the protocol and trialing a second region for greater resolution of the Pseudopanax species cluster. The method used is relatively simple to employ, and resulted in no mortality of host or tuber. The ability to accurately identify hosts paves the way for the creation of an accurate host list which reflects the true host range and preferences of Dactylanthus taylorii. Globally, few host lists are accurate, and this poses significant challenges for managers. Future work will expand upon this study, collecting host root samples from populations across New Zealand to determine host preferences.