Thierry Winkel

Genetic structure of quinoa (Chenopodium quinoa Willd.) from the Bolivian altiplano as revealed by RAPD markers

Quinoa (Chenopodium quinoa Willd.) is a pseudocereal originated from the Andes important for small farmers’ food security as well as for commercial production. Recently, it has been claimed that in Bolivia genetic erosion could result from the marginalization of the crop in the north and from its commercial standardization in the south. The aim of this study was to quantify the hierarchical structure of the genetic variation present in eight quinoa field populations, consisting of cultivated and weedy individuals, representative of the altiplano and interandean valleys of Bolivia. Randomly amplified polymorphic DNA markers show that quinoa has a strong population structure and a high intra-population variation. An effect of geographical structure of the populations was highlighted, due to population isolation, not simply linked to distance but more probably to climatic and orographic barriers present in the studied zone. The population structure is also reinforced by the limited seed exchanges among farmers as revealed by field interviews. This population structure appears related to three major biogeographic zones: the northern and central altiplano, the interandean valley, and the southern Salar. Intrapopulation genetic diversity was higher than that expected for a mainly autogamous species, and higher than that reported in anterior studies based on germplasm collections. These results are commented in view of current knowledge on phylogeny and reproductive biology of the species, and their implications regarding genetic resources management are discussed.

Calling for a reappraisal of the impact of quinoa expansion on agricultural sustainability in the Andean highlands

espanolEl debate sobre la sustentabilidad ambiental y social de la quinoa en el area de mayor produccion en el mundo (tierras Andinas del sur de Bolivia) revivio con la aceptacion por las Naciones Unidas de la propuesta de Bolivia de declarar el ano 2013 como el Ano Internacional de la Quinoa. El debate publico se focalizo en los impactos locales de la expansion de la quinoa en las tierras Andinas del sur de Bolivia, denunciando diversos impactos negativos del cultivo de la quinoa tales como la degradacion del suelo, conflictos socioeconomicos y perdida de biodiversidad. Sin embargo, las implicancias internacionales o globales de la expansion del mercado de la quinoa fue menos debatido y a menudo cariturizado, fluctuando entre culpabilidad e ingenuidad entre consumidores en tanto que productores Andinos eran descritos como atrapados por la pobreza o una avaricia miope. Si los investigadores han de hacer un aporte relevante al debate del impacto de la expansion de la quinoa sobre la sustentabili-dad social y ambiental de la agricultura Andina, entonces es necesario reevaluar el conocimiento e ignorancia actual sobre los sistemas de produccion andina en forma integrada con escalas globales, teniendo presente las interacciones locales- globales. En el presente estudio son revisadas algunas aseveraciones desafortunadas mas importantes expresadas en este debate utilizando tras clases de argumentos para fundamentar la necesidad de un enfoque mas cauto y etico en los problemas relacionados con la quinoa. EnglishThe debate on the environmental and social sustentainability of quinoa in its area of major world production (southern highlands of Bolivia) revived with the acceptance by the United Nations of the Bolivian proposal to declare in 2013 as the Year of the Quinoa. Public debate focused on local impacts of quinoa expansion in the Southern highlands of Bolivia, denouncing several negative impacts of quinoa culture such as land degradation, socioeconomic disrupts and biodiversity loss. However, the global or at least the international implications of the expanding quinoa market were less debated and often in caricature, varying between culpability and ingenuity among consumers, while Andean producers were described as trapped by poverty or short sighted greed. If researchers are to make a relevant contribution to the debate on the impact of quinoa expansion on the social and environmental sustainability of the Andean agriculture, is it necessary to re-evaluate present knowledge and ignorance about local Andean production systems integrated with links at the global scales, taking into account local- global interactions. In the present paper are revisited some major ill- founded assertions commonly expressed in this debate and three lines of arguments are used to support the need for a more cautious and ethical approach to quinoa related issues.

Rain-fed agriculture thrived despite climate degradation in the pre-Hispanic arid Andes

Simple yet extensive landscape modifications made past agrarian societies resilient to climate change. Archaeological research suggests significant human occupation in the arid Andean highlands during the 13th to 15th centuries, whereas paleoclimatic studies reveal prolonged drier and colder conditions during that period. Which subsistence strategy supported local societies in this harsh environment? Our field and aerial surveys of archaeological dwelling sites, granaries, and croplands provide the first evidence of extended pre-Hispanic agriculture supporting dense human populations in the arid Andes of Bolivia. This unique agricultural system associated with quinoa cultivation was unirrigated, consisting of simple yet extensive landscape modifications. It relied on highly specific environmental knowledge and a set of water-saving practices, including microterracing and biennial fallowing. This intense agricultural activity developed during a period of unfavorable climatic change on a regional and global scale, illustrative of efficient adaptive strategies to cope with this climatic change.

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

History and environment shape crop biodiversity, particularly in areas with vulnerable human communities and ecosystems. Tracing crop biodiversity over time helps understand how rural societies cope with anthropogenic or climatic changes. Exceptionally well preserved ancient DNA of quinoa (Chenopodium quinoa Willd.) from the cold and arid Andes of Argentina has allowed us to track changes and continuities in quinoa diversity over 18 centuries, by coupling genotyping of 157 ancient and modern seeds by 24 SSR markers with cluster and coalescence analyses. Cluster analyses revealed clear population patterns separating modern and ancient quinoas. Coalescence-based analyses revealed that genetic drift within a single population cannot explain genetic differentiation among ancient and modern quinoas. The hypothesis of a genetic bottleneck related to the Spanish Conquest also does not seem to apply at a local scale. Instead, the most likely scenario is the replacement 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 metapopulation scale, they support the view that gene pool replacement linked to social and environmental changes can result from opposite agricultural trajectories.