SUMMARY. Brown leaf rust affects wheat in all the regions of its cultivation. Its causative agent, Puccinia triticina Erikss, is a highly specialized plant fungal pathogen with a complex life cycle and alternating primary and intermediate host plants. Infecting the plants with the patho gen impairs the immunity of wheat varieties and deteriorates the photosynthetic activity of the plant, leading to reduced seed yield and decreased qualitative indices of wheat grain. New strategies for combatting brown leaf rust are based on research into the molecular and genetic interactions between the pathogen and plant cells. At the molecular level, the initial stages of plant-pathogen interaction involve many complex reactions, including the formation of pathogen-associated molecular patterns. Effector proteins, pathogen virulence factors involved in suppressing defense responses and metabolic activity of the host, play a leading role in host infection. Most genes of resistance to Puccinia triticina Erikss are race-specific. The studies of pathogen populations and resistant genotypes in various countries around the world make it possible to trace effective Lr resistance genes in wheat varieties. The application of modern molecular technologies for labelling individual genes and loci of quantitative traits enables the assessment of genetic diversity, the identification of genes, and their pyramiding for the development of new genotypes and their use in breeding and genetic programs for resistance to wheat rust.
Keywords: wheat, brown leaf rust, life cycle, defense responses, resistance genes, gene cloning, molecular markers, quantitative trait loci
