People have grown potatoes in the Sacred Valley of the Incas in Peru – a rugged stretch of the Andes – for thousands of years, writes Erik Stokstad in an article published on the Science website . In recent years, that task has gotten tougher, in part because of climate change. Drought and frost are striking more often. The rains come later, shortening the growing season. And warmer temperatures have allowed moths and weevils to encroach from lower elevations.
To find potatoes that can cope with those challenges, researchers and Peruvian farmers are testing dozens of the 4350 locally cultivated varieties, or landraces, kept in CIP’s refrigerated storage.
In Peru and around the world, enhancing the potato has become a high priority. It is the most important food crop after wheat and rice. Potatoes are already a staple for 1.3 billion people, and the nutritious tubers are becoming increasingly popular in the developing world.
Keeping up with the demand means adapting the potato to various soils and climates. It must also resist new threats from pests, disease, heat, and drought.
Unlike other major crops, however, the potato has not had a breeding breakthrough of the kind that helped dramatically boost yields during the Green Revolution of the 1950s and 1960s. The reason is that creating a new potato variety is slow and difficult, even by the patient standards of plant breeders. Readying a new variety for farm fields can take a decade or more.
Many countries continue to plant popular potato varieties that have remained essentially unchanged for decades. But new approaches, including genetic engineering, promise to add more options.
Potato breeders are particularly excited about a radical new way of creating better varieties. This system, called hybrid diploid breeding, could cut the time required by more than half, make it easier to combine traits in one variety, and allow farmers to plant seeds instead of bulky chunks of tuber. “It will change the world tremendously,” says Paul Struik, an agronomist at Wageningen University in the Netherlands.
Hybrid breeding “could be a real game changer,” says geneticist Glenn Bryan, head of the Potato Genetics and Breeding group at the James Hutton Institute in Dundee, U.K. “It will definitely make breeding more agile.”
Patient breeders using traditional methods can nevertheless achieve impressive results. In 2017, for example, CIP released four new varieties in Kenya, the result of crosses from established breeding lines. In field trials, the new potato plants maintained yields with 20% less rainfall and temperatures higher by 3°C.
Such success shows there is still genetic diversity to be tapped in existing breeding lines. But researchers fear that gene pool may not be deep enough to adapt the potato to future climates or enable other improvements.
Wild potatoes, however, hold valuable, untapped genetic diversity.