Effectiveness of Stem Rust Resistance Genes in Southern Russia

Wheat stem rust (caused by Puccinia graminis f.sp. tritici) is a damaging disease widespread in all grain-producing regions of the world. In this work, the effectiveness of Sr genes was analysed under field conditions in the southern region of Russia (Krasnodar Krai, Stavropol Krai and Rostov Oblast) during 2016-2021. The data were obtained using a set of 46 isogenic lines and varieties with artificial inoculation. The Sr31 gene proved absolute effectiveness in the field. Effective (1R–10R) Sr genes were the following: 5, 12, 35 and 37; moderately effective (10MR–30MR) Sr genes: 1, 6, 9g, 10, 11, 13, 14, 15, 20, 22, 23, 24, 25, 32, 33, 38 and WLD. Lines with Sr genes 7a, 7b, 8a, 8b, 9a, 9b, 9d, 9e, 9f, 16, 17, 19, 21, 26, 27, 29, 30, 36, 39, 40, 44, Dp2, Gt and Tmp were ineffective in the adult plant phase (30MS–70S). Polymorphism of infection types and disease severity was noted for most of these lines in different years. Ongoing analysis of the efficiency of Sr genes in the region is important to prevent the risk of epidemics, and lines with stem rust resistance genes that have shown efficiency can be used as donors in breeding programmes.