Research suggests that some resistance genes for the disease failed to transfer to new varieties during breeding
In an effort to improve clubroot resistance, new research suggests breeders tap into an old cultivar with fighting powers many commercial canola crops are likely without.
The cultivar, called ECD 04, contains clubroot-resistant genes likely lost when breeders created new canola varieties, suggests research from Alberta Agriculture.
They found that when breeders used ECD 04 to create a cultivar called Mendel, it’s possible that some critical clubroot-resistant genes didn’t transfer over.
Mendel has been used to create many of today’s commercial varieties, which means they would also likely be without those important genes, said Rudolph Fredua-Agyeman, a research scientist with the pest surveillance branch at Alberta Agriculture.
“During breeding, you cross one plant to the other and then you do several more cycles of breeding,” he said. “So, it’s possible the genes got lost in that process and I think that’s what the research finding points to.”
Fredua-Agyeman and his research team tested strains of clubroot in crops derived from ECD 04, Mendel and other commercial varieties. They found that ECD 04 was entirely resistant to clubroot, while Mendel and the commercial varieties failed to hold up as well.
“If you use the Mendel resistance, you only get resistance to the old strains of clubroot,” he said. “Some people are using the rutabaga resistance, and that’s only resisting some of the new strains. But if you go back to ECD 04, you are getting resistance to all the old strains and all the new strains. It means resistance from ECD 04 is strong enough against all the pathogens of clubroot.”
The findings, he said, suggest it might be best for breeders to go back and use ECD 04 when they’re creating new commercial varieties.
“There’s hope for the canola industry because of this new finding,” he said. “The resistance that we thought was lost has been there all along. The problem is we lost it because at the time we couldn’t track it, but now there are scientific ways of tracking this gene.”
The finding adds another tool to help in the fight against clubroot, said Stephen Strelkov, a University of Alberta professor in the department of agricultural, food and nutritional sciences. Strelkov has been conducting research to figure out where clubroot is spreading and how the pathogen is changing.
His research has recently found 12 new clubroot strains that are affecting farms in Alberta. There are now 103 fields in the province that are no longer as resistant to clubroot as they once were, he said.
“It’s definitely of concern. Genetic resistance is by far our most effective and important clubroot management tool.”
However, he said it’s important farmers follow proper management practices to improve resistance. This includes longer crop rotations, less tillage and the sanitization of equipment. It’s expected new resistant varieties will be available within 10 years.
“Lots of things are changing in a big hurry and we need to get farmers up to speed on what’s going on and how they can best handle the problems,” said John Guelly, a farmer in Westlock and director with the Alberta Canola Producers C ommission.
“There’s definitely more tools every day but, as far as a silver bullet to get rid of our diseases, I don’t think that’s realistic. It’s a lot more than one or two tools; it’s using all of those tools together.”
Fredua-Agyeman said his research team plans to test 55 different types of germplasm to find other sources of resistance not found in ECD 04.