Domestication and lowland adaptation of coastal preceramic maize from Paredones, Peru

Abstract

Archaeological cobs from Paredones and Huaca Prieta (Peru) represent some of the oldest maize known to date, yet they present relevant phenotypic traits corresponding to domesticated maize. This contrasts with the earliest Mexican macro-specimens from Guila Naquitz and San Marcos, which are phenotypically intermediate for these traits, even though they date more recently in time. To gain insights into the origins of ancient Peruvian maize, we sequenced DNA from three Paredones specimens dating ~6700–5000 calibrated years before present (BP), conducting comparative analyses with two teosinte subspecies (Zea mays ssp. mexicana and parviglumis) and extant maize, that include highland and lowland landraces from Mesoamerica and South America. We show that Paredones maize originated from the same domestication event as Mexican maize and was domesticated by ~6700 BP, implying rapid dispersal followed by improvement. Paredones maize shows no relevant gene flow from mexicana, smaller than that observed in teosinte parviglumis. Thus, Paredones samples represent the only maize without confounding mexicana variation found to date. It also harbors significantly fewer alleles previously found to be adaptive to highlands, but not of alleles adaptive to lowlands, supporting a lowland migration route. Our overall results imply that Paredones maize originated in Mesoamerica, arrived in Peru without mexicana introgression through a rapid lowland migration route, and underwent improvements in both Mesoamerica and South America.

North American pitseed goosefoot (Chenopodium berlandieri) is a genetic resource to improve Andean quinoa (C. quinoa)

“…3B) analyses indicate that these two taxonomic entities most likely arose through separate domestication events and remained separated, as was likely the case with the amaranths, another set of secondary crop-pseudocereals of New World origin [85][86][87] . These results contrast with maize and tomato, primary crops www.nature.com/scientificreports/ whose evolution as domesticates involved geographic translocation between their Mesoamerican and Andean centers of origin, respectively [88][89][90] . Huauzontle accession PI 433231 from Mesoamerica and QQ74 quinoa from the Chilean Central Valley differ by two large inversions (3B, 4B), a complex series of rearrangements on 5A, and a 4A-6B reciprocal translocation (Fig.…”

Two teosintes made modern maize

“…Samples from South America that reflect dispersal events before maize colonization of the Mexican highlands should thus not exhibit evidence of admixture with mexicana. Indeed, tests of admixture find no evidence of mexicana ancestry in N16, a ~5500 cal BP maize cob from northern Peru ( 37 ).…”