THE SACRED VALLEY OF THE INCAS IN PERU — On a bleak, brown hill here, David Ellis examines a test plot of potato plants and shakes his head. “They’re dead, dead, dead,” he says. Pests and lack of rain have laid waste to all 17 varieties that researchers had planted.
It is a worrying sign for Ellis, the now-retired director of the gene bank at the International Potato Center (CIP) in Lima. People have grown potatoes in this rugged stretch of the Andes for thousands of years. 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. The plants in this plot fell short. “Native landraces evolved over time,” Ellis says. But, he says, climate change is happening “too fast for these varieties to adapt.”
To breed a better potato, it helps to have plenty of genetic raw material on hand. But the world’s gene banks aren’t fully stocked with the richest source of valuable genes: the 107 potato species that grow in the wild. Habitat loss threatens many populations of those plants. In a bid to preserve that wild diversity before it vanishes, collectors have made their biggest push ever, part of a $50 million program coordinated by the Crop Trust, a charity based in Bonn, Germany.
The Crop Trust has provided grants and training to collectors around the world. The effort on wild potatoes, which wraps up this month, has yielded a collection representing 39 species from six nations: Peru, Brazil, Ecuador, Guatemala, Costa Rica, and Chile.
Researchers fear the gene pool of existing breeding lines may not be deep enough to adapt the potato to future climates or enable other improvements. Wild potatoes, however, hold valuable, untapped genetic diversity. One trait from those wild plants, “could save our life,” says Thiago Mendes, a potato breeder with CIP’s regional office in Nairobi. “Our target is food security.”