The first cultivated potato was grown in what is now Peru, researchers said Monday, and it originated only once, not several times, as some experts had proposed.
Their genetic study shows the first potato known to have been farmed is genetically closest to a species now found only in southern Peru, the U.S. and British researchers said.
“This result shows the potato originated one time and from a species that was distributed in southern Peru,” said David Spooner, a U.S. Department of Agriculture researcher at the University of Wisconsin who led the study.
The findings challenge theories that potatoes were first cultivated in Bolivia or Argentina, or that farmers bred them several different times in several different places.
“The origin of crop plants has long fascinated botanists, archaeologists and sociologists with the following fundamental questions: When, where, how, why, and how many times did crop domestication occur? What are the wild progenitors of these crops?” they wrote in their report, published in the Proceedings of the National Academy of Sciences.
The study did not address when the first potato would have been cultivated, but other research suggests it would have been between 7,000 and 10,000 years ago.
Major food staple
Potatoes are a major food staple around the world and mostly belong to a single species, Solanum tuberosum. Baking potatoes, red potatoes, golden potatoes and other favorites all originated in southern Chile, neighboring Peru, Spooner said in a telephone interview.
The Chilean potato that gave rise to modern potatoes is probably a hybrid of the ancestral Peruvian potato and a wild species found in Bolivia and Argentina, Spooner said.
But in South America, many other cultivated potatoes are eaten. “There are many different colors — solid and mottled and dotted from white to tan to purple to red,” Spooner said.
Fossil potatoes dating back 7,000 years have been found.
Genetic comparisons
For their study, Spooner and colleagues did genetic comparisons of 261 wild relatives of potatoes and 98 so-called landrace types, which are primitive cultivated crops grown by indigenous peoples.
The U.S. and British researchers believe their findings show a single species, S. bukasovii, gave rise to first known cultivated potato. It would not have closely resembled the big, pale fleshy tubers that people crave today, Spooner said.
“The wild species, many of them have tubers — the potato part you eat — that is tiny, sometimes the size of a pea,” he said. “Oftentimes they are mildly poisonous.”
