The studies were conducted in the Lababoratory of plant immunity Agricultural Research Institute for South-East Regions Russia. The samples of pathogen populations were collected from commercial and promising cultivars of spring and winter bread wheat at the end of their growing season at the maximum level of disease development in a field nursery. Then this inoculum's has been propagated on susceptible cultivars of bread wheat in the laboratory conditions. During three years of studies (2017-2019) 30 monopustules isolates has been studied. These studied isolates were avirulent to Thatcher near isogenic lines with genes Lr41, Lr42, Lr43+24, Lr53 and virulent to Lr1, Lr2a, Lr2b, Lr2c, Lr3, Lr3bg, Lr3ka, Lr10, Lr11, Lr12, Lr13, Lr14a, Lr14b, Lr15, Lr16, Lr17, Lr18, Lr21, lr22a, lr22b, lr25, lr28, LR 30, Lr32, Lr33, Lr34, Lr35, lr36, lr37, LR 38, Lr40, LR44, Lr45, LR b, LR W, LR Erph, LR Kanred, Lr57, Lr67. The significant variation for virulence was observed in lines with the Lr20, Lr23, Lr24, Lr26, Lr29, and Lr47 genes. The study of the P. triticina population structure in 2017-2019 revealed a partial loss of the effectiveness of the Lr47 gene. It was found that populations of P. triticina in 2017-2019 were characterized by high virulence.
