Methodological Approaches to the Determination of Race Non-Specific Resistance to <i>Puccinia graminis Pers. f. sp. tritici Erikss. et Henn.</i>
Recently, much attention has been paid to the issue of creating cultivars with partial resistance of a race nonspecific type, which is expressed in the slow development of the disease in a receptive type of reaction and can persist for a long period. Cultivars that are characterized by partial stability or incomplete stability possess race nonspecific resistance. Such cultivars have a high type of infection combined with delayed development of the disease. The main criteria for the determination of race non-specific resistance have been identified. They include the presence of a low type of plant reaction to infection with various races and biotypes of the fungus; manifestation of a long latent period; the number of pustules formed per unit area of the leaf is less in comparison with the susceptible cultivar; weak spore-forming ability of pustules; a smaller value of the area under the curve of the disease development in comparison with the susceptible cultivar. The research has resulted in the selection and study of spring wheat hybrids with race nonspecific resistance to Puccinia graminis Pers. f. sp. tritici Erikss. et Henn.