Winter Rye Varieties That Can Be Used as Sources of Resistance against Fungal Diseases in Phytoimmunity Breeding

Abstract

The purpose of this study was to identify new sources of nonspecific resistance against most harmful diseases for the purposes of winter rye phytoimmunity breeding. The study was conducted in 2020–2022 in Kirov oblast. More than 140 domestic winter rye varieties were examined against the following infection-provocation backgrounds: snow mold, powdery mildew, brown and stem rust, Septoria leaf blotch, root rot, and ergot. The disease rates were estimated using commonly accepted techniques. The progress of fungal diseases in varietal biocoenoses was analyzed over the course of plant ontogenesis (phases 31 to 85 on the Zadoks growth scale). The plant–microbial interactions and resistance parameters were assessed based on two indices: AUDPC (area under disease progress curve) and RI (resistance index). In total, 28 varieties distinguished by nonspecific resistance to two or more diseases and slow progress of diseases in varietal biocoenoses (the slow rusting trait) were identified: Lika, Garmoniya, Simfoniya, Perepel, Grafit, Grafit FP, Era, Evrika, Vikras, Yantarnaya, Chusovaya, Saratovskaya 7, etc. These varieties can be used as sources in phytoimmunity breeding. Among them, the most high-yielding (840–1060 g/m²) varieties are Batist, Dymka, Perepel, Lika, Simfoniya, Kiprez, Grafit FP, Flora, Evrika, Dana, Marusen’ka, Era, Saratovskaya 7, and Chusovaya. The correlation coefficient (r) between yield capacity and aftergrowth after snow mold damages varies from 0.49 (2022) to 0.87 (2020), which confirms the high harmfulness of this disease in the studied region. The following varieties are of certain immunological value in terms of breeding for ergot resistance: Rada, Kiprez, Flora, Lika, Batist, Garmoniya, Simfoniya, and Chusovaya; compared to the standard and other varieties, they are significantly more resistant to ergot. The composed regression equations are linear (R² = 0.96–0.99) and indicate daily progress of brown rust (5.4–16.4%) and stem rust (4.7–26.5%).