A total 65,153 M2 and 14,217 control plants were examined after artificial inoculation with powdery mildew. One resistant plant (type 1) in the variety 'Kurtovska kapia' from irradiation with 60 Gy and two resistant plants (type 1) in the variety 'Albena' were found. From M2 to M8 only seeds from the resistant plants of variety 'Kurtovska kapia' were collected for the next generation (Table 1) and the progeny of each plant was again tested after artificial inoculation. After Mg the seeds from the resistant plants were bulked and performance trials were conducted.