Physiologic specialization of wheat leaf rust (Puccinia triticina Eriks.) in the Slovak Republic in 2009-2011

In 2009–2011 virulence of the wheat leaf rust population was studied on Thatcher near-isogenic lines with Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr11, Lr13, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. Samples of leaf rust were obtained from different parts of the Slovak Republic. A total of 122 wheat leaf rust isolates were analysed. Resistance gene Lr19 was effective to all tested isolates. Virulence to Lr9 was found, however only in one isolate. Gene Lr24 conditioned resistance to almost all rust collections. A lower frequency of virulence to Lr2a and Lr28 was also observed. Nineteen winter wheat cultivars grown in Slovakia were tested with 8 leaf rust isolates. Winter wheat cultivar Bona Dea was resistant to all isolates applied in the greenhouse test. Presence of Lr genes was estimated according to the reactions of the tested cultivars. Presence of Lr10, Lr26, Lr34 and Lr37 was studied by molecular markers.