Select your language

Historical collections reveal patterns of diffusion of sweet potato in Oceania obscured by modern plant movements and recombination

Roullier Caroline, Benoit Laure, McKey Doyle B., Lebot Vincent. 2013. PNAS.
Historical collections reveal patterns of diffusion of sweet potato in Oceania obscured by modern plant movements and recombination
ARTICLE, (2013 ) - PUBLISHEDVERSION - English (en-GB)
PNAS
RESTRICTEDACCESS - Cirad license.
Audience : RESEARCHERS
PNAS Early Edition
Subject
F70 - Taxonomie végétale et phytogéographie, F30 - Génétique et amélioration des plantes, Ipomoea batatas, Histoire naturelle, Domestication des plantes, Distribution géographique, Provenance, Génétique des populations, Marqueur génétique, Chloroplaste, Microsatellite, Herbier, Phénotype, Évolution, Collection de matériel génétique
Domains
Agriculture
Description
The history of sweet potato in the Pacific has long been an enigma. Archaeological, linguistic, and ethnobotanical data suggest that prehistoric human-mediated dispersal events contributed to the distribution in Oceania of this American domesticate. According to the "tripartite hypothesis," sweet potatowas introduced into Oceania from South America in pre-Columbian times and was then later newly introduced, and diffused widely across the Pacific, by Europeans via two historically documented routes from Mexico and the Caribbean. Although sweet potato is the most convincing example of putative pre-Columbian connections between human occupants of Polynesia and South America, the search for genetic evidence of pre-Columbian dispersal of sweet potato into Oceania has been inconclusive. Our study attempts to fill this gap. Using complementary sets of markers (chloroplast and nuclear microsatellites) and both modern and herbarium samples, we test the tripartite hypothesis. Our results provide strong support for prehistoric transfer(s) of sweet potato from South America (Peru-Ecuador region) into Polynesia. Our results also document a temporal shift in the pattern of distribution of genetic variation in sweet potato in Oceania. Later reintroductions, accompanied by recombination between distinct sweet potato gene pools, have reshuffled the crop's initial genetic base, obscuring primary patterns of diffusion and, at the same time, giving rise to an impressive number of local variants. Moreover, our study shows that phenotypes, names, and neutral genes do not necessarily share completely parallel evolutionary histories. Multidisciplinary approaches, thus, appear necessary for accurate reconstruction of the intertwined histories of plants and humans. (Résumé d'auteur)
Keywords
phylogeography, herbarium specimens, prehistory, early trans-Pacific travels
Language
English (en-GB)
Creators
Roullier Caroline, Benoit Laure, McKey Doyle B., Lebot Vincent
Contributors
Sources
Proceedings of the National Academy of Sciences of the United States of America
Coverage
Amérique du Sud, Océanie, Pérou, Équateur
Name of newspaper
PNAS