The threat of myrtle rust to the conservation of the endangered tree, 'Gossia gonoclada' (Myrtaceae) in south east Queensland

Abstract

Myrtle rust (Puccinia psidii) is a fungal plant pathogen that rapidly spread throughout vegetation along the east coast of Australia after its detection in 2010. This biotrophic fungus has an unusually large number of host species, with 346 taxa from 57 genera within the Myrtaceae family identified as being susceptible (Giblin and Carnegie, 2014). The disease caused by the fungus adversely affects the growth of new shoots and leaves and, in highly susceptible species, all the new season’s foliage growth dies. In some species, recurrent infection of buds prevents flower and fruit development, which is likely to have long-term impacts on reproduction. Gossia gonoclada is an endangered species that is highly susceptible to myrtle rust. Data collected over the last three years indicate that the disease is affecting the health and reproductive capacity of the species.