VIEW ARTICLE

Letter to the Editor: An Appraisal of Stem and Leaf Rust Resistance in North American Hard Red Spring Wheats and the Probability of Multiple Mutations to Virulence in Populations of Cereal Rust Fungi. J. A. Kolmer and P. L. Dyck, Agriculture Canada, Research Station, 195 Dafoe Rd., Winnipeg, MB, Canada R3T 2M9; and A. P. Roelfs, Cereal Rust Laboratory, USDA-ARS, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Phytopathology 81:237-239.