Project number: 62042
PhD student: Papori Barua
Status: Completed

Project Summary

The rise in global movement of people and commodities, particularly from regions or countries posing a high biosecurity risk, increases the likelihood of incursion(s) of new fungal pathogens into new areas via spore contamination of biological and/or inert ‘carrier materials’. Many of these exotic fungal pathogens pose a threat to our agricultural, horticultural and natural ecosystems if introduced and established in Australia e.g. wheat stem rust, UG99.

This research project defines the relative likelihood of, and means by which, viable exotic fungal spore incursions on or in different carrier materials can occur by assessing common pathogen species including Leptosphaeria maculans, Kabatiella caulivora, Puccinia graminis f. sp. tritici and Magnaporthe oryzae in Australia and deliver new knowledge, skills, techniques and capacity to better detect and manage future exotic fungal spore incursions into Australia.

This is the first research to bring new understanding on critical importance of inert materials as long-term carriers of viable fungal pathogen conidia, resting hyphae, ascospores and urediniospores across different temperatures. A critical finding is the extended viability of these fungal spores with ability to germinate on artificial media and/or to infect relevant specific hosts and introduce new diseases into Australia. A rapid method for detecting viable fungal spores been developed by novel application of a resazurin (Alamar Blue) assay. Germination of viable spores from the test carrier materials could be impeded using fungicides and disinfectants.

Impact

The findings have major implications, both highlighting how commodities can effectively carry and retain viable fungal spores for much longer time periods than previously considered possible, and also how the same applies for between growing seasons in the absence of a growing host.

This work brings new understanding on managing fungal contaminations in relation to exotic fungal pathogen spores that could be introduced into Australia through carrier materials previously considered as low-risk; and will be beneficial to the Commonwealth Department of Agriculture and Water Resources, Plant Health Australia, state government biosecurity agencies, other government agencies including the Department of Defence, research and private industries.