1. F 4 Population VBSD Quantiles of scores Expected scores Vascular Browning Score Number of lines VBS Quantiles of scores Expected scores Vascular Browning Score Number of lines 3 3 a b Supplementary Fig. 2 Histogram and normal-scores plot of a) VBSD, b) VBS, c) LS, d) VBSD and e) % survival in F4 families. Arrows reflects mean value of parental controls; solid = MCU-5, dotted = Siokra 1-4.

2. F 4 Population LS Quantiles the scores Expected scores Leaf symptom Score Number of lines LSWTD Quantiles the scores Expected scores Leaf symptoms weighted for death Number of lines 3 3 c d Supplementary Fig. 2 Continued

3. F 4 Population % Survival Quantiles the scores Expected scores Percent survival Number of lines 3 e Supplementary Fig. 2 Continued