Structure of P. triticina fungus populations on varieties and breeding lines of bread wheat on Omsk SAU experimental field in 2013-2015

Monitoring of virulence of fungus P. triticina populations collected on Omsk SAU experimental field, on released and promising varieties and breeding lines of bread wheat in 2015 was performed. All tested isolates were avirulent on Thatcher near-isogenic lines (Tc) Lr19 and Lr24. The variability of the infection type on lines TsLr2a, TsLr9, Ts14b, TsLr16, TsLr20 and TsLr26 was observed. Among 210 analysed monopustuled isolates 8 virulence phenotypes were revealed. Phenotypes TGR, TQR, THR with different virulence to genes Lr9 and Lr26 were the most represented. In general, genetic differences on virulence between populations collected from different wheat entries were not significant with exception of variety Stolypinskaya population. As a result of durable analysis of Omsk populations (2013-2015), their high virulence (frequency 80-100%) to genes Lr1, Lr2a, Lr3a, Lr3bg, Lr3ka, Lr10, Lr11, Lr14a, Lr14b, Lr15, Lr16, Lr17, Lr18, Lr30 and avirulence to genes Lr19, Lr24, Lr41, Lr42, Lr51, Lr53, Lr64, Lr65 were detected. A significant polymorphism on virulence on lines TsLr9, TsLr26 and TsLr20 was observed. Two phenotype groups TGQ and TGR, THQ and THR with different virulence to gene Lr20 were predominated for all years of research. Phenotype TQR with avirulence on lines TcLr19, TcLr24 and TcLr26 was observed annually with frequency of 19.2 to 10%. In general, significant changes in the structure of populations on Omsk SAU experimental field were not revealed during three years.