RA1B WEBINAR: A. psidii - the threat of other ...

Austropuccinia psidii*: the threat of other strains

March 2021

Soewarto J. 2021. Austropuccinia psidii: the threat of other strains. Beyond Myrtle Rust Webinar Series. 15/03/2021

ABSTRACT

The pandemic strain of Austropuccinia psidii (myrtle rust) present in New Zealand is the most widely distributed strain of the pathogen globally. It is also different to the strains present in South America and in South Africa, which have different host ranges and severity. If these other myrtle rust strains were introduced into New Zealand, this could lead to additional myrtle species becoming infected, making myrtle rust an even more serious threat to our natural diversity. As part of biosecurity preparedness research for New Zealand, local researchers are working with scientists in South Africa and Uruguay to test the susceptibility of New Zealand germplasm against different strains of A. psidii.

This presentation is run by Scion-based researcher Julia Soewarto, where she focuses on the results from the artificial inoculation of the South African strain of A. psidii on four iconic New Zealand species: Leptospermum scoparium (mānuka), Kunzea robusta (kanuka), K. linearis (mānuka rawiri) and Metrosideros excelsa (pōhutukawa). This study provided new insights into the host range of the South African strain of A. psidii and suggested it represents a serious threat for New Zealand native Myrtaceae and for other Myrtaceae species worldwide.