Figure 1. (a) Coupling-phase RAPD marker OAD12.550 and (b) SCAR marker SOAD12.537 amplified with the specific primer pair designed from the sequence of the RAPD marker OAD12.550 expressing polymorphism between two DNA bulks from susceptible and resistant F₂ plants, between the susceptible parent GN Nebr.#1 and the resistant parent GN1140, and between the susceptible line A 55 and the resistant line BelNeb-RR-1. 1 = a 100-bp DNA marker ladder, 2 = GN Nebr.#1, 3 = GN1140, 4 = DNA bulk from susceptible F₂ plants, 5 = DNA bulk from resistant F₂ plants, 6 = A 55, and 7 = BelNeb-RR-1.