Abstract

Bread wheat is the most important food crops among cereals cultivated in the world and consume in various diets. However, the production of bread wheat majorly affected by fungal diseases especially rust diseases. Of the rust diseases, stem rust is the most destructive due to the frequent emerging of new races of the pathogen. The field experiment was conducted at Kulumsa Agricultural Research Debre Zeyit sub-center using 36 genotypes during 2015 cropping season, and the greenhouse experiment was carried out at Ambo Plant Protection Research Center to evaluate bread wheat genotypes for resistance/tolerance to wheat stem rust disease adult and seedling stages, respectively. For field experiment, the treatments were arranged in the randomized complete block design with three replications. Stem rust evaluations for Pgt races TTKSK, TKTTF, TRTTF and JRCQC were replicated so that a total of at least 20 seedlings from each cultivar were evaluated. At seedling stage, most of the genotypes confirm low IT ≤2 on four of the stem rust races indicating that they are resistance to the four stem rust races used. Out of these, nine of the gentypes namly genotype ETBW7178, ETBW7198, ETBW7236, ETBW7220, ETBW7161, ETBW7191 and one standard chick Dand’a  has  potential (IT≤1) to overcome stem rust races at sedling stage. On the experiment for adult stage, the only genotype showing strong resictance was genotype ETBW7178 (5R). The rest genotypes show moderately resistance, moderately susceptible and totally susceptible to stem rust inoculums used. These results can assist wheat breeders in Ethiopia for choosing parents for crossing in programs aimed at developing cultivars with desirable levels of stem rust resistance in collabration with International Maize and Wheat Improvement Center (CIMMYT) and will also facilitate stacking of resistance genes into advanced breeding lines.

Key words: Genotypes, inoculums, resistance, suscepitable.