Inheritance of Powdery Mildew Resistance in Wheat Line IL72-2219-1. S. A. Sebastian, Former Graduate Assistant, Agronomy Department, Pennsylvania State University, University Park 16802. M. L. Risius, Professor of Plant Breeding, Agronomy Department, and M. H. Royer, Research Assistant, Department of Plant Pathology, Pennsylvania State University, University Park 16802. Plant Dis. 67:943-945. Accepted for publication 3 February 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-943.

Experiments were conducted to study the inheritance of powdery mildew (Pm) (Erysiphe graminis f. sp. tritici) resistance in an experimental wheat (Triticum aestivum) line IL72-2219-1, which was crossed with the Pm-susceptible cultivars Hart and Blueboy to obtain F₂ and testcross progeny. When segregating generations were tested with a single powdery mildew isolate (144), a qualitative single dominant gene inheritance pattern was observed. Nonsegregating wheat host lines (including IL72-2219-1, Hart, Blueboy, Va66-54-10, and Arthur) were tested for reaction to six differential mildew isolates. The reactions of each line to the six isolates were then compared with reactions of near-isogenic wheat lines with known genes for resistance. Both IL72-2219-1 and its seed parent, Va66-54-10, appear to contain gene Pm3a.