Race Composition of the Novosibirsk Population of Puccinia graminis f. sp. tritici

Western Siberia consists of areas with different climate and agricultural requirements and independent pathogenic populations of wheat stem rust characterized by specific migration pathways and sources of renewed infection. Monitoring surveys of stem rust populations in the vast territory of the region should be carried out using a universal set of wheat differential lines with known resistance genes to determine the phytosanitary situation, as well as to integrate data on global migration of virulent races. The Global Rust Reference Center (GRRC) is currently implementing the requirements of standard guidelines for dealing with rust fungi and race typing. In this article, race analysis and virulence structure of stem rust population in the Novosibirsk oblast were studied in the Global Rust Reference Center, GRRC (Denmark), and in the laboratory of molecular phytopathology of ICG SB RAS (Russia), organized in accordance with GRRC standards. A total of 40 single pustule isolates of Puccinia graminis f. sp. tritici were obtained from infection samples and differentiated into races. The local population of the Novosibirsk oblast was identified as heterogeneous with the dominant pathotypes TKRPF, QCRSF, QCHSF. It is important there were no races from the aggressive family of Ug99 strains in the region. After race comparison, Omsk and Altai subpopulations were assumed which had independent sources of genetic diversity and a zone of contact and mixing in wheat crops of the Novosibirsk oblast. Based on similarity of the dominant races, the Novosibirsk population is most dependent on the inoculum of Omsk origin.