Fig. 4From: Genetic variation for tolerance to the downy mildew pathogen Peronospora variabilis in genetic resources of quinoa (Chenopodium quinoa)Linkage disequilibrium and population structure. a Decay of linkage disequilibrium (LD) expressed as a function of physical distance (kb) and r2. b Plot of the first two principal components of a PCA analysis. Percentages in each label are the proportion of variance explained by each PC; colors indicate the country of origin as indicated in the passport dataBack to article page