Based on the analysis of the intraspecific structure of the fungus Zimoseptoria. tritici, it was found that this species has significant polymorphism. Using monogenic wheat lines (Oasis (Stb1), Veranopolis (Stb2), Israel (Stb3), Tadinia (Stb4), CS / Synthetic (Stb5), Estanzuela Federal (Stb7)), the population of Z. tritici in the Central Black Earth region was tested. High heterogeneity of monosporous isolates of Z. tritici by virulence was revealed.