Resistance to Erysiphe graminis f. sp. tritici, Puccinia recondita f. sp. tritici, and Septoria nodorum in Wild Triticum Species. J. R. Tomerlin, Research Plant Pathologist, USDA, ARS, Beltsville Agricultural Research Center, Beltsville, MD 20705. M. A. El-Morshidy, Research Geneticist, University of Assiut, Assiut, Egypt; J. G. Moseman, Research Plant Pathologist, and P. S. Baenziger, Research Geneticist, USDA, ARS, Beltsville Agricultural Research Center, Beltsville, MD 20705; and G. Kimber, Professor, Department of Agronomy, University of Missouri, Columbia 65211.. Plant Dis. 68:10-13. Accepted for publication 7 July 1983. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-10.

Seventy-nine accessions encompassing 23 Triticum species were inoculated with cultures or culture composites of Erysiphe graminis f. sp. tritici, Puccinia recondita f. sp. tritici, or Septoria nodorum. The cultures of E. graminis and P. recondita were chosen so that most of the virulence genes found in the eastern United States were represented. Powdery mildew and leaf rust ratings were bimodally distributed, with high ratings outnumbering low ratings by as much as 1.8 to 1. Ratings of leaf symptoms caused by S. nodorum were skewed toward resistance and susceptibility outnumbered resistance by as much as 4.1 to 1. Reaction to S. nodorum was correlated with reaction to E. graminis. Triticum carthlicum may be a source of resistance to E. graminis, T. monococcum may provide resistance to E. graminis and P. recondita, and resistance to E. graminis, P. recondita, and S. nodorum may be found in the T. timopheevi population. Nine accessions had resistance to all three pathogens. Seven of these were highly pubescent. The association of resistance to leaf pubescence may affect the expression of any resistance transferred to T. aestivum.