A new Department of Primary Industries and Regional Development Science Partnership project is developing new strategies to improve control of the serious canola disease Turnip yellows virus (TuYV).
TuYV is an aphid-borne viral disease spread by aphids, primarily the green peach aphid, which can halve yields and reduce seed quality.
Severe epidemics have occurred frequently across Australia over the past decade, including a significant outbreak in the Esperance Port Zone in 2018 and large parts of south eastern Australia in 2014.
The department is collaborating with Melbourne-based research and extension organisation, Cesar Australia, on the broad ranging project.
It builds on the department’s Grains Flagship research that developed an early warning system to detect TuYV.
Project lead, department research scientist Ben Congdon, said the new project sought to explore the application of the early warning system in decision support by consultants and industry.
“The system uses Loop-mediated isothermal AMPlification, known as LAMP technology, to detect TuYV in winged migratory aphids on yellow sticky traps before the virus reaches epidemic levels in the crop,” Dr Congdon said.
“While the LAMP assay itself has been field validated, this next step will test the early warning system as a decision tool with follow-up virus testing of the crop to assess the outcomes of management decisions made.
“We will also study the implications of seed treatment use, stubble retention, variety choice and weed control and other relevant variables on virus spread at these sites and in a series of field and glasshouse experiments.”
Another major component of the Science Partnership project aims to identify host resistance in Brassica plants and gain insights into the genetic drivers of resistance in order to develop tools to help breed new and improved varieties.
“We are examining a diverse range of germplasm across the broader brassica genus, including cabbage, Brussel sprouts, kale, Chinese cabbage and pak choi,” Dr Congdon said.
“We have already identified several rapeseed lines with resistance to TuYV infection and accumulation in the plant tissue that offer potential as breeding material.”
The next step will include a collaboration with DPIRD’s Doubled Haploid program to identify the sources of resistance.
“Once we identify the genetic drivers of resistance, we can develop screening tools to help breeders develop commercially available TuYV resistant varieties that provide growers with improved TuYV control in high disease pressure scenarios,” Dr Congdon said.
The project will also investigate use of other control measures, including seed treatment and foliar insecticides, and factors that impact their efficacy.
Cesar Australia will test the appropriateness of the TuYV early warning system in Victoria, as well as investigate insecticide resistance in GPA.
Director, Associate Professor Paul Umina, said Cesar Australia would examine the impact of resistance on aphid survival when exposed to canola sown with different insecticide seed treatments, as well as the impact of ambient temperature on TuYV and aphids in canola.
The department will examine the abiotic impacts, like soil moisture and soil type.
“Identifying potential factors influencing active ingredient uptake and subsequent survival rates of GPA will contribute to an improved understanding of insecticide resistance and control failure risks for this pest,” Professor Umina said.
“This research will give growers greater confidence in the control tools and systems used to manage TuYV and GPA and help avoid significant yield losses in the future.”
New resources and novel strategies for integrated management of GPA and TuYV in canola crops will be developed as part of the project.
Jodie Thomson/Megan Broad, media liaison
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