Validation of a real-time PCR protocol to detect Ceratocystis lukuohia and C. huliohia from Aotearoa New Zealand Metrosideros species

Ceratocystis lukuohia, the cause of ōhi’a wilt disease, and C. huliohia, the cause of ōhi’a canker disease (collectively known as rapid ōhi’a death or ROD), have resulted in widespread death of ‘ōhi’a lehua (Metrosideros polymorpha) in Hawai’i. Aotearoa New Zealand Metrosideros species, such as the iconic pōhutukawa and rātā, are closely related to M. polymorpha. The pathogens are not currently present in Aotearoa New Zealand but should either of these pathogens establish in this country, they could affect endemic and indigenous Metrosideros species. In this study, the use of a real-time PCR protocol, developed in Hawai’i to detect and differentiate C. lukuohia and C. huliohia from ōhi’a plant tissue, was validated for three Metrosideros species from Aotearoa New Zealand.