Sorghum racial identity and subpopulation structure. PCA plot of the 580 exotic progenitor (EP) lines genotyped in this study. Each dot represents an EP line, colored according to its morphologically-defined race. Larger circles and smaller triangles represent EP lines with more and fewer than 10% unexpected genotypes, respectively. The grey dashed lines indicate the criteria used to assign EP lines to genetic groups for subpopulation-specific introgression mapping.
Thurber et al. Genome Biology 2013 14:R68 doi:10.1186/gb-2013-14-6-r68