Puccinia triticina population structure on winter and spring wheat in Saratov region during 2013–2017
Keywords:Puccinia triticina, population, monopustules, isolates, Lr-genes, virulence, avirulence
The analysis of the Puccinia triticina Ericss Saratov population’s structure on the wheat for virulence genes during 2013–2017 is provided. Infectious material has been collected from winter and spring bread wheat cultivars and lines of ARISER bred. These cultivars and lines have varying degrees of pathogen severity: from moderate (10–20 %) to high (70–90 %). The studies of virulence genes in the P. triticina population were performed on the cultivar Thatcher set of near isogenic lines (NIR), which contained 52 lines with identified Lr-genes. Ten monopustules isolates were isolated from pathogen populations. The composition of the pathogen populations for virulence genes was determined by its infection type on NIRs. It is established that P. triticina populations in 2013–2017 was characterized as highly virulent. The number of virulence genes ranged from 40 to 44, but the number of resistant genes varied from 6 to 9. The main differences in the population compositions were in the different types of reactions to Lr9, Lr19, Lr23, Lr24, Lr29 genes. These genes showed resistance, then susceptible type of reaction to P. triticina. During 2013–2017, the high efficiency of Lr41, Lr42, Lr43+24, Lr47, Lr53 genes was observed. The use of these genes in breeding will expand the genetic diversity of new cultivars and stabilize the pathogen population composition. These data indicate the need for continuous monitoring of the P. triticina population composition for the virulence genes frequency, which will allow to develop a strategy of resistant cultivars breeding and spread them in the wheat cultivation regions.