The FINANCIAL — The ground-breaking sequencing of the blackleg fungus genome is helping to direct ongoing canola industry research efforts.
The blackleg fungus Leptosphaeria maculans is the most damaging disease of canola and juncea-canola in Australia. In some circumstances this disease can cause up to 90 per cent yield loss.
The sequencing of the genome of the blackleg fungus by a team of Australian and French scientists, announced earlier this year, is already having a positive impact on the canola industry through development of new approaches to predict disease outbreaks.
Grains Research and Development Corporation (GRDC) Manager for Crop Protection, Dr Rohan Rainbow, says sequencing of the genome of the blackleg fungus will help researchers understand the fungus’ rapid and potentially devastating genetic evolution and improve opportunities to explore alternate disease control mechanisms.
He says researchers will also have a greater ability to predict likely blackleg outbreaks and be able to direct growers to more resistant canola varieties before planting.
“Understanding the genetic make-up of the blackleg fungus will help us accelerate control,” Dr Rainbow said.
“It provides a whole range of options and is a significant step forward for the GRDC and growers both in Australia and in other countries.”
During the past five years, the GRDC has invested $3.76 million into blackleg fungus research programs.
Dr Rainbow said the GRDC will continue its focus on commercialisation of research to ensure growers see tangible benefits from investment.
A team of French and Australian scientists, jointly led by Professor Barbara Howlett from the School of Botany at the University of Melbourne, sequenced the genome of the blackleg fungus, announcing and publishing their discovery in February this year.
Professor Howlett said sequencing the genome has enabled researchers to develop molecular markers that can predict whether disease outbreaks will occur, or their likelihood of occurring, in a given season.
For growers, this equates to increased knowledge of likely disease outbreaks and the chance to switch to a more resistant canola variety.
Professor Howlett said scientists were now focusing on uncovering how the blackleg fungus causes the deadly disease.
Dr Steve Marcroft, of Marcroft Grains Pathology in Horsham, Victoria, said the sequencing of the genome would have profitable repercussions for growers.
“We are setting up a system where we can take a sample from canola stubble, collect spores and run molecular tests quickly and cheaply,” he said.
“We will be able to tell growers the frequency of blackleg spores that are able to attack resistance genes within an individual canola cultivar and if the frequency has increased.
“If it is occurring at high levels, we will be able to advise growers to switch to a variety with resistance from a different gene.
“With a molecular test, we don’t need to grow plants out to know if they will get infected – genome tests are a far more timely and cost-effective solution.”
To date, the research teams have identified many of the seedling resistance genes; once all corresponding virulence genes in the fungus are mapped, researchers will be able to monitor fungal populations for these genes, Dr Marcroft said.
“We’ll be able to monitor the fungal population in many different canola growing regions and then give warnings if virulence against individual canola cultivars has increased,” Dr Marcroft said.
“We’ll know if the frequency of attacking spores increases from 5% in year one to 15% the following year, in that scenario it is highly likely increased disease levels will occur in a particular area and growers should plant a different canola variety.”