Multi-Environment Field Evaluation of Winter Rye Genetic Resources in Russia Reveals Promising Accessions for Improving Fusarium Head Blight Resistance

Fusarium head blight (FHB) is one of the most devastating diseases of cereal crops worldwide, causing yield losses and mycotoxin contamination. Traditionally associated with warm and humid climates, FHB has increasingly affected cooler and drier regions, including the Volga region of Russia—a major grain-producing area once considered low-risk. In this three-year field study, we evaluated FHB resistance in 50 winter rye accessions under natural infection and artificially enriched infectious backgrounds using high-virulence Fusarium strains from the Volga region. Post-invasive resistance to FHB was generally weak across the tested germplasm. Nevertheless, considerable variability in FHB damage was observed among accessions. Accessions showing the lowest overall FHB severity were identified as promising donors for breeding programs. Specific resistance sources to individual Fusarium species were identified, notably Fusarium sporotrichioides—previously regarded as a weak pathogen but demonstrated here as a serious food safety threat. No significant positive correlation was found between FHB severity and mycotoxin levels, confirming these as partially independent traits; several accessions maintained low mycotoxin content despite severe symptoms. Our study highlights the necessity of multi-environment screening with local pathogen strains and endorses pyramiding approaches for durable FHB resistance in winter rye breeding.