Figure 6. Principle of selective genotyping and bulk segregant analysis. The method of selective genotyping implies the selection of individuals with extremely high and low phenotypic values (within the shaded area) from the continuous distribution of a quantitative trait of interest. The selected individuals are genotyped and association is tested. Bulking segregant analysis advances selective genotyping approach one step further by bulking selected individuals at each of the two extreme trails, with each tail represented only by one bulk sample.