Abstract
Sixty accessions of Aegilops squarrosa (= Triticum tauschii Schmal) were evaluated for resistance to leaf rust (Puccinia recondita f. sp. tritici) culture PRTUS6; powdery mildew (Erysiphe graminis f. sp. tritici) composite cultures ABK, 127, YUMA CC, and Asosan; greenbug (Schizaphis graminum) biotype E; and Hessian fly (Mayetiola destructor) biotype D. Thirty-two accessions were resistant to the leaf rust pathogen, 31 to the powdery mildew pathogen, and 34 to the greenbug; 24 were homozygous and 16 were segregating for resistance to the Hessian fly. Multiple resistance was widespread and six accessions were resistant to both pathogens and both insects. Resistance varied from immune to moderate reactions. Because A. squarrosa is the donor of the D genome in common wheat, this species can be readily exploited in breeding wheats for pest resistance.