ARS research has traced modern potatoes' origins
back to primitive tubers from Chile, such as those pictured above (photo
courtesy Andrés Contreras, Universidad Austral de Chile). Below, ARS
botanist David Spooner (right) and Alberto Salas of the International Potato
Center in Peru collect potato germplasm during an expedition in
Unraveling the Mystery of Modern Potatoes'
Origins By Erin
Peabody March 18, 2005
When it comes to veggies, almost everyone can agree on potatoes. But
despite its popularity, the common brown potato has a colorful history that
some researchers are still disputing.
While potatoes are believed to have arrived in Europe in the 1500s
from the South American Andes, Agricultural
Research Service botanist
M. Spooner has uncovered DNA evidence showing that early potatoes also came
from South America's southwestern coast, in lowland Chile.
From outward appearances, modern potatoes would seem to have Chilean
ancestors. European potato plants have wide leaflets like Chilean ones, and
both are "long-day adapted," which means they require the longer days of summer
to form tubers.
But in the 1930s, researchers started challenging the notion of the
Chilean connection, arguing that the first potatoes to reach Europe came only
from the Andes. They claimed Chilean potatoes couldn't have survived the long
journey from their native country, down through the Straits of Magellan and
across the Atlantic.
According to Spooner, who works in the ARS
Crops Research Unit at Madison, Wis., potato seeds can last several years
and so could have easily survived the trip. But even more compelling are data
he recently assessed with colleagues at the International Potato Center in Lima, Peru,
and the Central Potato Research Institute in Shimla, India.
The researchers surveyed an assortment of potatoes from India
considered to be remnants of some of the first potatoes to Europe. They found
that these descendants share specific molecular traits with potatoes from
Chile--not the Andes.
Still, some argue that Chilean potatoes weren't introduced to Europe
until after the famous 1840s Irish potato famine, to rescue the crop from the
rot-causing late blight fungus. But, as Spooner points out, Chilean potatoes
aren't known for having resistance to late blight.
With an increased understanding of modern potatoes' true ancestors,
scientists can better preserve the world's potato plants to breed future
varieties and realize the crop's natural disease- and insect-resistance
ARS is the U.S. Department of
Agriculture's chief scientific research agency.