Search for immunologically valuable winter rye genotypes using separate parameters of non-specific resistance

More than 100 Russian varieties and collection samples of winter rye were studied under the conditions of the Kirov region against the natural infectious background of the development of mycoses (2019-2020). The degree of damage by powdery mildew during the years of research reached 86.3 %, septoria – 63.3 %, brown rust – 40.5 %, stem rust – 60.0 %, rhynchosporiosis – 29.3 %. During plant ontogenesis (from phases 31 to 85 Zadoks scale), the growth of fungal infection in varietal biocenoses was analyzed. When accounting for diseases, well-known methods were used. The nature of plant-microbial interactions and the parameters of resistance were assessed by indicators of ADDC (area under the curve of disease development), IR (resistance index) and LP (latency period). A close relationship was established between the duration of LP and the degree of septoria infection (r = -0.98), brown rust (r = -0.95), powdery mildew (r = -0.92), stem rust (r = -0.80), rhynchosporiosis (r = -0.67). The regression equations are linear (R2 = 0.84 ... 0.96) and indicate a daily increase in diseases (from 0.52 to 0.88 %). In the course of immunological management, there have been identified about 20 varieties of Russian selection distinguished by nonspecific resistance to two or more diseases, slow (slow rusting) growth of infection in varietal biocenoses and a long latent period of pathogenesis. Among them are the varieties of the Federal Agricultural Research Center of the North-East named N.V. Rudnitsky (Falyonskaya 4, Vyatka 2, Rushnik, Kirovskaya 89, Snezhana, Flora, Rumba), other scientific institutions of the Russian Federation (Alisa, Pamyati Bambysheva, P-01/14, GP-901 and others) and new samples from the VIR collection (Trinodis 4 Minvak – 139/09 NP, Estet NP 42/14 and others). They can be used in breeding as sources, and indicators of ADDC, IR, LP – as immunologically significant parameters of nonspecific resistance.