Virulence of Puccinia triticina on Triticum and Aegilops species

Abstract

Virulence of 347 single-uredinial isolates of Puccinia triticina from 16 species of Aegilops and Triticum grown in experimental fields with natural inoculum in Dagestan (Caucasus region of Russia) and Novosibirsk (West Siberian region of Russia) and in an artificially inoculated field in Shortandy (Northern Kazakhstan) was analyzed with 20 near-isogenic wheat differential lines. All isolates were avirulent to Lr9, Lr19, and Lr24, and virulent to Lr11, Lr14a, Lr17a, and Lr30 genes. The P. triticina isolates varied for virulence on resistance genes Lr1, Lr2a, Lr2b, Lr2с, Lr3a, Lr3bg, Lr3ka, Lr14b, Lr15, Lr16, Lr18, Lr20, and Lr26. Forty virulence phenotypes of P. triticina were identified, of which seven virulence phenotypes were shared by at least two hosts. The virulence analysis revealed differences between P. triticina from diploid, tetraploid and hexaploid species of wheat. Collections from the hexaploid species in Dagestan were more similar to those from common wheat. Isolates from tetraploid species were less virulent. Asian isolates (Novosibirsk and Northern Kazakhstan) originating from common wheat and T. dicoccum were more virulent than those from Caucasus.