Discontinuities in quinoa biodiversity in the dry Andes: An 18-century perspective based on allelic genotyping

WINKEL, THIERRY; AGUIRRE, MARÍA GABRIELA; ARIZIO, CARLA MARCELA; ASCHERO, CARLOS ALBERTO; BABOT, MARÍA DEL PILAR; BENOIT, LAURE; BURGARELLA, CONCETTA; COSTA-TÁRTARA, SABRINA; DUBOIS, MARIE-PIERRE; GAY, LAURÈNE; HOCSMAN, SALOMÓN; JULLIEN, MARGAUX; LÓPEZ-CAMPENY, SARA MARÍA LUISA; MANIFESTO, MARÍA MARCELA; NAVASCUÉS, MIGUEL; OLISZEWSKI, NURIT; PINTAR, ELIZABETH; ZENBOUDJI, SALIHA; BERTERO, HÉCTOR DANIEL; JOFFRE, RICHARD

PLOS ONE

PUBLIC LIBRARY SCIENCE

Año: 2018 vol. 13 p. 1 - 13

1932-6203

History and environment shape crop biodiversity, particularly in areas with vulnerablehuman communities and ecosystems. Tracing crop biodiversity over time helps understandhow rural societies cope with anthropogenic or climatic changes. Exceptionally well preserved ancient DNA of quinoa (Chenopodium quinoa Willd.) from the cold and arid Andesof Argentina has allowed us to track changes and continuities in quinoa diversity over 18centuries, by coupling genotyping of 157 ancient and modern seeds by 24 SSR markerswith cluster and coalescence analyses. Cluster analyses revealed clear population patternsseparating modern and ancient quinoas. Coalescence-based analyses revealed thatgenetic drift within a single population cannot explain genetic differentiation among ancientand modern quinoas. The hypothesis of a genetic bottle neck related to the Spanish Conquest also does not seem to apply at a local scale. Instead, the most likely scenario is there placement of preexisting quinoa gene pools with new ones of lower genetic diversity. This process occurred at least twice in the last 18 centuries: first, between the 6th and 12th centuries a time of agricultural intensification well before the Inka and Spanish conquests?and then between the 13th century and today?a period marked by farming marginalization in the late 19th century likely due to a severe multidecadal drought. While these processes of local gene pool replacement do not imply losses of genetic diversity at the meta population scale, they support the view that gene pool replacement linked to social and environmental changes can result from opposite agricultural trajectories.