Canola Breeding ON THE PRAIRIES, clubroot appeared in Alberta in 2003, in Saskatchewan in 2008 and Manitoba in 2013. As any grower can tell you, it’s a nasty canola disease that usually worsens in a field every year, partly because the spores are very easy to spread and so hardy they can survive for up to two decades in the soil. Combine this fact with the strong prices that canola fetches these days – widely encouraging back-to-back or two-year rotations – and you have a big problem. Companies are certainly moving as quickly as possible to produce seed with effective resistance to clubroot, but breeding to defend against this particular pathogen involves navigating a wide range of complex challenges. “Clubroot has a very short lifecycle resulting in several generations per season,” explains Dr. Marcus Weidler, vice president of seed operations at Bayer CropScience, “enabling the pathogen to react to changes in its environment very quickly, including new crop resistance genes.” Dr. Jed Christianson, pathology lead at Monsanto Canada, explains that clubroot’s large and quickly-adapting population sizes means that it takes relatively long canola rotations of three or four years to see significant drops in the number of viable spores in the soil, and very long rotations of over 10 years for spores to effectively disappear. “Each gall produced on a canola root can contain billions of spores,” he says. “So, given the numbers of spores generated, even very rare events like the emergence of individual spores that have gained the ability to infect resistant canola will happen over a fairly short number of cropping cycles. A one in a billion event doesn’t seem that unlikely to happen when you’re given 20 billion chances.” An update on breeding clubroot-resistant canola. CLUBBING CLUBROOT While Bayer CropScience undertakes much canola breeding research, such as in the greenhouse pictured, clubroot resistance research is conducted in a highly-secure lab to prevent the spread of the pathogen. Photo: Bayer CropScience 46 www.seed.ab.ca | Advancing Seed in Alberta