Response of introduced durum wheat varieties to races of the powdery mildew (Erysiphe graminis DC f.sp. tritici) causal agent in the region of Plovdiv.

The resistance of durum wheat varieties to the powdery mildew pathogen (Erysiphe graminis DC f.sp. tritici) was studied during 2008-2009 at the IPGR in Sadovo. The study established that the varieties immune to the powdery mildew pathogen were as follows: 87102151, 87102152, Balkan TS 1926, FAP-1 2383 and Prag ruzyne I. Some different five varieties: 87110002, 88110001, 87110014, 87110015, and Prag ruzyne II showed resistant reaction to the pathogen. The Prag ruzyne variety was attacked by races 43, 107 and 110 of the pathogen (type of damage 4) in the second-leaf stage and showed an immune reaction to the other races. In the ear-formation stage that variety showed a susceptible reaction to the 30S/3 type of damage in the first year and to 40S/2 in the second. Immune varieties can be used in combined breeding for development of varieties resistant to the powdery mildew pathogen.