A load of potatoes waits to be unloaded for packaging at W.P. Griffin Inc. in Elmsdale, PEI, on April 20, 2022.DARREN CALABRESE/The Globe and Mail
Whether it comes boiled, baked or French fried, the humble potato is the world’s third-most consumed food crop after rice and wheat – and the one with the lowest carbon footprint.
Now a Canadian-led team has assembled the most extensive genetic roadmap of the potato to date, along with its closest relatives, in order to bolster the plant’s ability to cope with climate change and protect its future as a mainstay of global food security and sustainability.
“It’s basically enabling us to see what kind of genetic diversity is possible for the potato and what kind of traits we could potentially breed into our modern-day cultivars,” said Martina Strömvik, a plant scientist at McGill University and a senior author on the study, published Monday in the Proceedings of the National Academy of Sciences.
A cultivar is a plant variety that is generated by selectively breeding plants with favourable traits.
The full DNA sequence of any single cultivar is called a genome, while a combination of sequences that includes multiple varieties of the same species is a pangenome.
In the new study, Dr. Strömvik’s lab was able to go one step further to produce a super-pangenome of the potato.
In addition to several domestic varieties, it identifies genetic variations that occur in related species, which can be crossed with the potato to produce hybrid offspring.
To construct the potato super-pangenome, the team drew on data made available through gene banks in the United States, Canada, Peru and elsewhere to compare 296 genomes from 60 species related to Solanum tuberosum, the domestic potato. The project was supported by federal and provincial funding agencies and by the Digital Research Alliance of Canada, which provided supercomputer time.
The point of all the number crunching is twofold, Dr. Strömvik said. On one hand, the result can help scientists trace the evolutionary history of the potato and its subsequent development since it was domesticated by Indigenous peoples in the Andes mountains of southern Peru some 10,000 years ago. On the other, it reveals specific genes that could be used to improve current versions of the potato plant and make them more resilient to extreme weather events linked to climate change.
Jeff Wood cultivates a potato field in New Tryon, PEI, on July 20, 2001.ANDREW VAUGHAN/CP
“What we would like to do is make something that can withstand a frost or a drought or lots of rain,” Dr. Strömvik said.
The superpangenome can also be mined for genetic variations that help defend against various forms of disease, which are expected to increasingly affect Canadian potato crops as winters become warmer on average and pathogens that are more prevalent in the U.S. migrate northward.
Dmytro Yevtushenko, an associate professor at the University of Lethbridge who specializes in potato biology but was not involved in the study, said he was excited by the result because “it will open a new route and new possibilities in molecular breeding.”
Speaking from the annual meeting of the Potato Association of America, an international gathering of potato scientists taking place this week in Charlottetown, Dr. Yevtushenko said the superpangenome can be used as a high-precision guide. Armed with CRISPR gene-editing technology, researchers can now create new, more resilient potato varieties on a timeline that is years shorter than would be possible with conventional breeding techniques.
In May, the federal government released updated guidelines that indicate new cultivars created in this way will not require special authorization if they do not pose a threat to the environment.
Ivan Semeniuk