A more efficient breeding against plant disease, or the development of new resistant lines, is enabled via the provision of the resistance-mediating gene according to the invention; in particular, a resistance effect in the target plant is evoked by the property of the identified gene. The resistance-mediating gene, and embodiments of the present invention that are described in the preceding, offer additional applications, e.g., the use of the resistant gene allele in trans-genetic approaches, with the goal of developing new resistant cultivars.