Resistance in Aegilops squarrosa to Wheat Leaf Rust, Wheat Powdery Mildew, Greenbug, and Hessian Fly. B. S. Gill, Associate Professor, ARS-USDA, Department of Plant Pathology, Kansas State University, Manhattan 66506. W. J. Raupp, Research Assistant, H. C. Sharma, Former Research Associate, and L. E. Browder, Research Plant Pathologist, ARS-USDA, Department of Plant Pathology, Kansas State University, Manhattan 66506; J. H. Hatchett, Research Entomologist, ARS-USDA, Department of Entomology, Kansas State University, Manhattan 66506; T. L. Harvey, Professor, Fort Hays Branch Experiment Station, Hays, KS 67601; J. G. Moseman, Research Plant Pathologist, Plant Genetics and Germplasm Institute, ARS-USDA, Beltsville, MD 20705; and J. G. Waines, Department of Botany and Plant Science, University of California, Riverside 92521. Plant Dis. 70:553-556. Accepted for publication 20 November 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-553.

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.