Detalle de: Phenotypic and genetic resistance to Septoria blotch disease in European wheat varieties

Zymoseptoria tritici , the causal agent of Septoria tritici blotch (STB), poses a critical threat to wheat ( Triticum aestivum L.) production in temperate Europe, underscoring the need for durable genetic resistance. Here, we screened 151 winter wheat varieties at the seedling stage using a mixed inoculum of five virulent isolates. Disease severity was quantified at 14, 21, and 28 days post‐inoculation to calculate the area under the disease progress curve. We observed broad phenotypic variation, with higher susceptibility in Southern European germplasm. A genome‐wide association study identified three significantly resistant loci: IWB5774 on chromosome 2D, and IWB72742 and IWB11406 on chromosome 1B. Functional annotation mapped these markers to high‐priority candidate genes, including a TaBx3D‐like protein, the endomembrane trafficking regulator WDR91 , and NAP1 , a nucleosome assembly factor involved in stress signaling. These findings provide robust molecular markers for breeding and nominate specific targets for functional validation of STB resistance mechanisms.