Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2005
Publication Date: 10/2/2005
Citation: Spooner, D.M., Mclean, K., Ramsay, G., Waugh, R., Bryan, G.J. 2005. A single domestication for potato based on multilocus AFLP genotyping. Proceedings of the National Academy of Sciences. 120:14694-14699. Interpretive Summary: The cultivated potato is technically known as Solanum tuberosum. It is native only to South America and southern Chile, where it was selected from wild potato species and maintained for millennia by indigenous people. The wild species progenitors of these landraces have long been in dispute, but all hypotheses center on a group of about 20 very similar appearing wild potatoes technically referred to as the "Solanum brevicaule complex," that grow throughout Peru, Bolivia, and Argentina. We analyze the DNA from these wild and primitive potato species to show that the primitive potatoes evolved from a group of wild potatoes in Peru, not from Bolivia and Argentina. We also show that these 20 wild potato species in the Solanum brevicaule complex are really fewer species, perhaps less than ten or so. The most significant finding is that cultivated potatoes evolved only one time, not many times as was previously thought. These results will help revise our ideas about how many times and where cultivated potatoes evolved. They also show potato breeders the group of wild potato species most similar to the cultivated ones.
Technical Abstract: The cultivated potato, Solanum tuberosum, ultimately traces its origin to Andean and Chilean landraces developed by pre-Colombian cultivators. These Andean landraces exhibit tremendous morphological and genetic diversity, and are distributed throughout the Andes, from western Venezuela to northern Argentina, and in southern Chile. The wild species progenitors of these landraces have long been in dispute, but all hypotheses center on a group of about 20 morphologically very similar tuber-bearing (Solanum section Petota) wild taxa referred to as the Solanum brevicaule complex, distributed from central Peru to northern Argentina. We present phylogenetic analyses based on representative cladistic diversity of 367 individual wild (275) and landrace (89) members of potato (all tuber-bearing) and three outgroup non-tuber-bearing members of Solanum section Etuberosum, genotyped with 438 robust Amplified Fragment Length Polymorphisms. Our analyses are consistent with a hypothesis of a "northern" (Peru) and "southern" (Bolivia and Argentina) cladistic split for members of the Solanum brevicaule complex, and with the need for considerable reduction of species in the complex. In contrast to all prior hypotheses our data support a monophyletic origin of the landrace cultivars from the northern component of this complex in Peru, rather than from multiple independent origins from various northern and southern members.