Supplementary Figure 7: Cumulative proportion of variance explained by the principal components for marker pairs showing significant epistatic effects.

Results were shown for (a) the 681 pairs of markers showing significant additive-by-additive epistatic effects, (b) the 205 pairs of markers displaying significant additive-by-dominance epistatic effects, and (c) the 380 pairs of markers revealing significant dominance-by-dominance epistatic effects. The dashed vertical lines indicate the number of PCs needed to explain 99% of the variance, which are 34 in (a), 15 in (b) and 46 in (c). The principal component analysis was performed based on the matrix whose columns consist of element-wise products of the vectors of relevant marker pairs.