Fig. 4

Genetic composition of switchgrass populations by geographic region. The genotypes are color-coded according to their affiliation to STRUCTURE subpopulations at K = 3 (C1: blue; C2: green; C3: red; admixed: gray) and grouped by geographic area. The circle size in each geographic area is proportional to the number of genotypes. USA Map was downloaded from https://upload.wikimedia.org/wikipedia/commons/c/ca/Blank_US_map_borders.svg