Canadian scientists are exploring diploid potato varieties that could help breeders develop more resilient, productive and sustainable crops for future farming challenges.
Agriculture and Agri-Food Canada (AAFC) researchers are exploring diploid potatoes as a potential alternative to conventional varieties, with research showing promising results for yield, storage, disease resistance and adaptability to changing climate conditions.
The findings could help strengthen potato breeding and support a more sustainable Canadian potato industry.
Dr. Bourlaye Fofana, a Research Scientist in Charlottetown, and Dr. Benoit Bizimungu, based in Fredericton, are investigating potatoes with two sets of chromosomes, compared with the four sets found in traditional tetraploid varieties.
Conventional potato breeding has relied heavily on a relatively narrow genetic pool of tetraploid potatoes. This has contributed to genetic similarities among commercial varieties, potentially limiting their ability to withstand emerging diseases and environmental stresses.
Diploid potatoes offer breeders a broader range of genetic traits and greater precision when developing improved varieties.
“Farmers have relied on tetraploid potatoes for decades because of their high yields, good storage traits, and their shallow root system that made them easier to harvest," said Dr. Fofana.
"Tetraploid potatoes have four sets of chromosomes, and for a long time, having more chromosomes was believed to be necessary for strong yields. But our research shows we don’t have to be limited by that assumption anymore. Diploid potatoes have enormous potential.”
Dr. Fofana's team evaluated 721 diploid potato clones developed through EMS mutagenesis, a technique that introduces genetic variations. The researchers identified differences in characteristics such as dormancy, root development, tuber size, colour, texture, starch content, and yield. From this collection, 54 promising candidates were selected for multi-year field trials.
More than 80% of the tested clones demonstrated acceptable or excellent tuber appearance. Marketable yields from 20% of the creamer varieties and 29% of the table or chip varieties matched or exceeded those of commercial tetraploid potatoes grown in Canada.
“In some cases, our best-performing diploid clones not only met the standards of tetraploid potatoes, but they also outperformed them,” explained Dr. Fofana.
Storage performance was another encouraging result. The tested diploid clones showed good to high tuber dormancy, helping prevent premature sprouting and supporting longer storage periods. This characteristic could help producers maintain consistent potato supplies throughout the year.
The research findings are expected to contribute to the Canadian Potato Gene Resources collection managed by Dr. Bizimungu's team at AAFC's Fredericton Research and Development Centre.
The collection contains more than 300 unique potato genetic resources and supports breeding programmes in Canada and internationally.
"By working at the diploid level, we gain more genetic precision. They are easier to breed, saving both time and resources in the development of improved varieties. The ability to produce high-quality tubers with fewer chromosomes offers opportunities for genetic diversity and improved genetics in breeding, making potatoes more resilient against climate change and diseases,” said Dr. Fofana.
Although some frying-type diploid potatoes have yet to match tetraploid yields, the results provide opportunities for further improvement. Researchers believe continued breeding could deliver productive, resilient varieties suited to Canadian farmers and processors.
Photo Credit: agriculture-and-agri-food-canada