Solanum tuberosum, is an American cultivar related to the tomato and the eggplant (Remarkably, they are all in the same genus, but rarely to all three appear in the same dish). Potatoes, the lovely underground storage organ (USO) without which we would not have French Fries, or dipping chips to eat during the Super Bowl, twice baked potatoes, or Mr. Potato Head and his family, were domesticated by Native Americans in two local centers, one in the high Andes in eastern Venezuela and northern Argentina, and in the lowlands of south-central Chile. During the last half of the 16th century, they spread worldwide, as did many other food crops.
The origin of the "European" version of the potato has been the subject of intense debate. Did the European potato come from the Andes or from Chile? Over the last several decades, the former has been the more accepted theory. The fact that all modern potato varieties show Chilean origins has been explained by the hypothesis that the Andean varieties were all wiped out by the great potato blights of the 19th century.
The Andean origin has been questioned recently through examination of landraces in India and the Canary Islands, but this evidence is inferential. Through a plastid DNA deletion marker from historical herbarium specimens, we report that the Andean potato predominated in the 1700s, but the Chilean potato was introduced into Europe as early as 1811 and became predominant long before the late blight epidemics in the UK. Our results provide the first direct evidence of these events and change the history of introduction of the European potato.
This is important for a number of reasons, aside from the refinement of historical reconstructions of the spread of food crops. The assumption has been, for some time, that the European potato came from the Andes. Selection on this type of potato is thought to have led to an improved crop in some regards, but also, to susceptibility to potato blight. So, getting the history right is very relevant to developing potato varieties that are both, well, good at being potatoes, and resistant to blight. If you have the history wrong, you may do this wrong.
Our data also highlight the critical importance of herbarium specimens in investigating historical origins of crop plants. Literally all data sets addressing the origin of the European potato before this study...were ambiguous, contradictory, and inferential. Molecular examinations ..., however, provide the first direct evidence to bear upon the long-held controversy of the extra-Andean origin of this major food plant and completely change our understanding of the history of the potato outside of South America.
Ames, M., Spooner, D. (2008). DNA from herbarium specimens settles a controversy about origins of the European potato. American Journal of Botony, 95, 252-257.