Scientists at New South Wales Department of Primary Industries’ Wagga Wagga Agricultural Institute have been studying the genetic makeup of canola plants in a bid to uncover the specific genes that govern resistance to fungal pathogen Leptosphaeria maculans. The pathogen causes blackleg, the major disease threat to Australia’s canola industry.
The DPI scientists’ finding paves the way for developing new canola varieties with “durable resistance” to blackleg disease.
According to NSW DPI senior principal research scientist Harsh Raman, the study has unpacked the genetic make-up of canola and has characterised major and minor genes resistant to the fungal pathogen Leptosphaeria maculans, LINK which causes blackleg disease.
“Blackleg disease can cause up to 80 per cent yield loss in canola,” Dr Raman notes. “In Australia, France and Canada, resistance has been broken down in some canola varieties due to the emergence of new races of the blackleg pathogen.
“Significantly for local canola growers, the study revealed new sources of blackleg resistance which were either resistant to the pathogen or had low levels of blackleg.”
The DPI researchers conducted a genome-wide association study using 18,804 DNA markers in a bid to identify genes associated with resistance (major and minor) in canola.
Using molecular DNA markers, they managed to map several genes for resistance on the canola chromosome. These, says DPI, will help in “incorporating a combination of genes that can be used to develop canola varieties with durable resistance to battle blackleg attack”.
To ensure a comprehensive evaluation, the researchers then screened numerous canola lines under glasshouse conditions, using known races of blackleg fungus collected from canola-growing sites across Australia to infect 180 varieties.
Who was involved?
The new genetic sources of resistance in canola were identified by researchers at the DPI Wagga Wagga Agricultural Institute. NSW DPI, in collaboration with Marcroft Grains Pathology and the Victorian Department of Primary Industries (DPI) has now validated the presence of new blackleg-resistant genes in a number of canola varieties.
The blackleg resistance research project was supported by the NSW, Victorian and Australian governments and by the Grains Research & Development Corporation (GRDC).