Wheat Leaf Rust: Genetic Basis of Resistance

Abstract— Wheat leaf rust affects wheat in all growing regions. Its causative agent, Puccinia triticina Erikss, is a highly specialized plant fungal pathogen with a complex life cycle and alternation of primary and intermediate host plants. The infection of plants by the pathogen disrupts the immunity of wheat varieties and impairs the photosynthetic activity of the plant, leading to reduced seed productivity and quality parameters of wheat grain. New strategies for controlling wheat leaf rust are based on studies of the molecular and genetic interaction of the pathogen with 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. A leading role in host infection is played by effector proteins, pathogen virulence factors that are involved in suppressing host defense responses and metabolic activity. Most resistance genes to Puccinia triticina Erikss are race-specific. Studies of pathogen populations and resistant genotypes in different countries around the world make it possible to track effective Lr resistance genes in wheat varieties. The use of modern molecular technologies for marking individual genes and quantitative trait loci provides for the assessment of genetic diversity, identification of genes, their pyramiding for the development of new genotypes, and their use in breeding and genetic programs for wheat rust resistance.