Wheat stem rust (Puccinia graminis f.sp tritici) is the most important one production constraint in Ethiopia. Cultivars with the same genes may increase the selection pressure for corresponding virulent races. Thus, knowledge of resistance genes in cultivars is important for deploying cultivars with different genes to reduce damage. This study was aimed to postulate resistance genes in Ethiopian durum wheat genotypes. Postulation of wheat stem rust resistance genes was done by challenging seedlings of 20 durum wheat varieties; 25 durum wheat lines and 20 monogenic lines using eleven races of Puccinia graminis f.sptritici (pgt) (TKTTF, TTKSK, TRTTF, JRCQC, RRTTF, TTRTF, TKPTF, TKKTF, TTKTF, TTKTT and TTTTF). Evalaution for types of Infection was done fourteen days after inoculation using 0-4 scale where 0-2 readings were regarded as incompatible reaction whereas 3-4 readings were regarded as compatible. Infection types produced on twenty monogenic lines and test entries were compared to postulate probable presence of respective resistance genes in the genotypes. Seven seedling stem rust resistance genes (Sr24, Sr5, Sr7b, Sr10, Sr38, Sr31, Sr11 and unidentified genes were postulated to be present in Ethiopian durum wheat cultivars and lines. Therefore, those genes could be used to enhance the diversity of stem rust resistance in wheat against virulent races of the wheat stem rust.

Keywords: Durum wheat, Infection type, Races, Resistance genes, Virulence, Puccinia graminis