Source: Saskatchewan Agriculture and Food
It is a perpetual race against time. Genetic manipulation for disease resistance through plant breeding is an art for which patience could be the greatest required virtue.
Ron Knox is a Pathologist at Agriculture and Agri-Food Canada’s (AAFC) Prairie Agricultural Research Centre in Swift Current.
“The time frame is an important consideration, always. We know it is just a matter of time before we see a mutation in the disease pathogen and the old resistance no longer does the job. It takes 10 to 12 years in general to develop cultivars that will not be adversely affected by the mixing of genes in the breeding process, and will exhibit the disease resistance trait. But sometimes it can take as many as 25 years,” Knox says.
“It's important in the breeding process, if possible, to have more than one line of resistance waiting in the wings. For example, Prairie plant breeders have done such a good job over the past 50 years in developing spring wheat varieties with common bunt resistance that the disease is rarely an issue for producers anymore,” explains Knox.
Common bunt, caused by a fungus, can attack spring and winter wheat crops. Prior to the development of chemical treatments and genetic resistance, it was regarded as one of the most devastating diseases of wheat in Canada and other countries.
The abundance of moisture producers have experienced has brought the work of Knox and his colleagues to the forefront again, as disease pressure increases with higher moisture levels. Interest is particularly strong regarding wheat disease resistance for Fusarium Head Blight (FHB) in the western Prairies.
In the eastern Prairies, FHB has been the most frustrating and costly wheat disease in decades. Though it hasn't become a major problem in the western Prairies, FHB nonetheless has become the most talked about concern for farmers and researchers in this part of the region.
“At a fundamental level, as plant breeders, we are there to help develop solutions that will benefit farmers. At a professional level, I find this type of work extremely rewarding,” Knox says. “You can track the differences in traits in the plants in the testing nurseries. You cross plants possessing beneficial traits with local varieties. In the progeny of these, you get a mix of genes from the adapted plants, plus the traits you were looking for, like disease resistance.
“You are hoping to introduce the new genes and reconstitute the genetics you knew worked. Finding the right mix of the many combinations of genes is a little bit like a lottery at times. You just have to keep trying until you pick the winning number.”
For more information, contact:
Ron Knox, Ph.D.
Pathologist
Prairie Agricultural Research Centre
Agriculture and Agri-Food Canada
(306) 778-7262
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