Resistance of bread wheat (Triticum aestivum L.) varieties to fusarium head blight (Fusarium graminearum) in Ethiopia

Fusarium head blight (FHB) is a devastating disease reduces wheat yield and quality. This study was aimed to evaluate wheat varieties' responses to spray inoculation with Fusarium graminearum mixture isolates under greenhouse conditions. The treatments were laid out in a randomized completely block design with three replications using 24 bread wheat varieties registered in Ethiopia. The varieties inoculated with mixed inoculum derived from four pathogenic isolates of F. graminearum that had been isolated from wheat kernels. Disease severity was evaluated using a 1–9 scale based on the proportion of bleached spikelets, and the area under disease progress curve (AUDPC) was determined from the disease severity data. At harvest, the kernel weight reduction was determined in comparison to the control. The evaluated traits were significantly interrelated and showed high and significant variation among (p < 0.0001) wheat varieties. Disease severity index among the varieties varied from 29% to 72%, while AUDPC varied from 326%- to 1010%-days. The disease progress rate of the Kingbird variety inoculated with F. graminearum was the slowest (0.0191 units day⁻¹), whereas Ogolcho had the fastest disease progression rate (0.0581 units day⁻¹). Kingbird, Wane, and Limu were moderately resistant, with lower disease severity, AUDPC, and a reduction in 1000-grain weight and grain weight per spike. Dereselgne, Dambal, and Ogolcho varieties were highly susceptible, with the greatest grain weight per spike reduction (53.2%, 41.4%, and 37.4%) and 1000-grain weight reduction (41.5%, 42.8%, and 37.5%), respectively. The results implied that there were different levels of FHB resistance in Ethiopian bread wheat varieties. Although current greenhouse evaluation of varieties gives encouraging results, field testing is required to confirm the current findings.