Sources of winter rye resistance to fungal diseases for phytoimmunity breeding

The work was carried out at the Federal Agrarian Scientific Center of the North-East in 2020–2022. More than 140 domestic varieties of winter rye were studied under conditions of Kirov region on provocative-infectious background of snow mold, powdery mildew, brown and stem rust, septoriosis, root rot, ergot. Commonly known methods were used to account for diseases. During the plant ontogenesis (from phase 31 to 85 on Zadoks scale), we analyzed the growth of fungal infection in the variety biocenoses. The nature of plant-microbe interactions and resistance parameters were evaluated according to two indicators PKRB (area under the disease development curve) and IS (resistance index). We identified 28 sortes characterized by nonspecific resistance to two or more diseases and slow (slow rusting) growth of infection in varietal biocenoses. Among them: Lika, Harmonia, Symphony, Perepel, Graphite, Graphite FP, Era, Eureka, Vikras, Amber, Chusovaya, Saratovskaya 7, etc. They can be used in breeding for phytoimmunity as sources. The highest yielding (840–1060 g/m²) among them are: Batiste, Dymka, Perepel, Lika, Symphony, Kiprez, Grafit FP, Flora, Eureka, Dana, Marusenka, Era, Saratovskaya 7, Chusovaya. The correlation coefficient (r) between the yield and regrowth after snow mold lesions varies from 0.49 (2022) to 0.87 (2020), which confirms the high harmfulness of this disease in the region. Rada, Kiprez, Flora, Lika, Batiste, Harmony, Symphony, Chusovaya can be of certain immunological value in breeding for ergot resistance, as they were much less affected by ergot than the standard and other varieties. The regression equations are linear (R² = 0,96–0,99) and show a daily increase of brown rust (from 5,4 to 16,4 %) and stem rust (from 4,7 to 26,5 %).