The global threat of Myrtle rust (AUSTROPUCCINIA psidii): Future prospects for control and breeding resistance in susceptible hosts

Austropuccinia psidii, (Basidiomycota; Pucciniales) (formerly Puccinia psidii), commonly known as Myrtle rust, is a fungal pathogen that has quickly become a global threat. The physiological infection cycle of A. psidii is comprised of distinct steps that are potential targets for host defense strategies or human-induced control methods. While genetic control has thus far seen the most progress for Myrtle rust management, the development and implementation of pre-penetration and preventative control methods have been largely neglected. By gaining a holistic understanding of the processes related to infection, reproduction, and genetic distribution of Myrtle rust, we can better inform our future decisions on prevention and control. In this review I outline the known genetic processes underlying pre- and post-haustoria resistance in Myrtaceae hosts, current and developing control methods related to these processes, and lesser known alternatives that could be implemented or expanded to control this prolific disease.