Abstract
The growing spread of particularly dangerous diseases (variations of rust) in the grain-bearing countries raises fears of the harmfulness of phytopathogens increasing. In the years favorable for their development, a sharp decrease in the productivity of the ear and the quality of the grain is observed. The high potential of the pathogen to produce new aggressive disease variations makes most grain varieties susceptible to this pathogen. To determine the immunological value of breeding lines of winter wheat, we conducted immunological studies on the experimental base of the Kazakh Research Institute of Agriculture and Plant Growing in 2015-2020. Under the conditions of artificial infectious background at a specialized facility, a targeted immunological assessment was carried out on 28 lines of irrigated winter bread wheat, 24 lines of rainfed winter bread wheat and 20 lines of winter durum wheat. An artificially infectious background was created using a population of rust uredospores: P. striiformis, P. triticina, P. graminis. According to the reaction to the pathogen population, the breeding lines were divided into resistance types according to the established disease resistance scales. The authors analyzed the state of resistance of the winter wheat line of Kazakhstan breeding to the rust population in the conditions of the southeast of Kazakhstan. The paper characterizes the reactions of breeding lines to rust pathogens P. striiformis, P. triticina, P. graminis. Based on the immunological assessment, two lines of common wheat, one line of soft wheat and four lines of durum wheat with resistance were isolated using a reaction to P. striiformis with no signs of disease. Five lines of common wheat showed moderate resistance to this pathogen. The other (79.2%) breeding lines of winter wheat were characterized as moderately susceptible and susceptible to the rust pathogen. The identified breeding lines combine high economically valuable traits (productivity) and resistance to yellow rust and are of the greatest immunological value. This proves the prospects and expediency of their further use in the breeding improvement of the local agroecotype of winter wheat.