Identification of sources of Fusarium head blight and deoxynivalenol resistance in Ethiopian wheat cultivars

Fusarium head blight (FHB), caused by Fusarium graminearum, poses a significant threat to wheat production in Ethiopia, causing yield losses of up to 30–70% in severe epidemics and contaminating grain with deoxynivalenol (DON). This study aimed to identify sources of FHB and DON toxin resistance among selected Ethiopian wheat cultivars. Forty-three cultivars were evaluated for FHB resistance under greenhouse and field conditions, using the spawn inoculation method. Disease index (DI), Fusarium-damaged kernels (FDK), and DON content were quantified. The mean DI across cultivars ranged from 2.33% to 56.8%, FDK from 1.2% to 48.5%, and DON from 0.12 to 8.64 mg kg⁻¹. Cultivar “Sulla” exhibited the highest level of FHB resistance with a stable DI of 2.33%, FDK of 1.8%, and DON content of 0.16 mg kg⁻¹—the first such finding reported in Ethiopian germplasm. Notably, cultivars “Menze”, “Shorima”, and “Lemu” displayed strong resistance to DON contamination, with toxin levels ≤ 0.25 mg kg⁻¹, exceeding previously reported resistance thresholds. Eleven cultivars, including “Sulla”, exhibited significantly reduced yield losses (< 10%) compared to controls, whereas cultivars such as “Abola”, “Alidoro”, “Kakaba”, “Kingbird”, and “Simba” accumulated the highest DON levels (≥ 6.5 mg kg⁻¹) and showed high susceptibility. Based on the specific molecular marker Xumn10, the Fhb1 resistance gene was detected in 23 cultivars and the resistant control, “Sumai-3”. These findings significantly expand the pool of resources for FHB and DON resistance in Ethiopian wheat breeding, with the potential to improve yields by up to 20% and reduce mycotoxin contamination by more than 80% in FHB hotspots.