Improving preparedness of the Australian horticultural sector to the threat potentially posed by Xylella fastidiosa (a severe biosecurity risk) (MT17006)

What was it all about?

From 2017 to 2023, this multi-industry investment updated the National Diagnostic Protocol for Xylella fastidiosa to ensure that Australia is adopting the world’s best practice methods. This work sets Australia up for quick and effective detection of what is considered to be the number one plant biosecurity threat to Australia and New Zealand, to facilitate a swift and sure response.

The Australian National Diagnostic Protocol (NDP) for X. fastidiosa was last updated in 2016, and the updated version has now been submitted to the Subcommittee for Plant Health Diagnostics (SPHD), Plant Health Australia (PHA), and will be made publicly available once it is endorsed.

The new version was broadened to encompass primary detection, diagnosis, and surveillance of all Xylella species, subspecies, and sequence types across a broad range of hosts.

The NDP includes a combination of extensively validated laboratory and field-based molecular assays, that were published by other international researchers or developed within the project, for the identification and differentiation of Xylella spp. down to sequence type and for use during high throughput surveillance. High throughput sequencing and rapid multilocus sequence typing methodologies were also developed, to enable accurate identification of Xylella species, subspecies, and sequence type to inform surveillance strategies based on host specificity. MPI developed a collection of accurately characterized Xylella spp. isolates, and DNA was shared with the Australian project participants; this critical resource not only assisted the NDP development but will support future Xylella spp. diagnosis and surveillance within Australia and New Zealand.

As well as developing state-of-the-art diagnostic tools, technologies and protocols to screen plant material entering the country and to support active surveillance programs, it provided associated training to technical staff in diagnostic laboratories.

Xylella fastidiosa is the number one exotic national priority pest for Australia due to its broad host range and the significant threat it poses to agricultural and horticulture industries. Outbreaks of X. fastidiosa have caused significant crop losses and socio-economic impacts overseas. X. fastidiosa is transmitted by insect vectors from one plant to another and can infect over 650 plants. The symptoms caused by X. fastidiosa include leaf scorch, chlorosis, and decline and often look like other disorders, such as water stress or nutrient deficiencies.