Relationship Between Development of Hard Red Winter Wheat and Expression of Resistance to Wheat Soilborne Mosaic Virus. C. R. Armitage, Graduate Research Assistant, Department of Plant Pathology, Oklahoma State University, Stillwater 74078-9947. R. M. Hunger, J. L. Sherwood, and D. L. Weeks. Associate Professor, Associate Professor, Department of Plant Pathology, and Professor, Department of Statistics, Oklahoma State University, Stillwater 74078-9947. Plant Dis. 74:356-359. Accepted for publication 24 November 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0356.

Expression of resistance to wheat soilborne mosaic in a field trial of susceptible winter wheat (Triticum aestivum) cultivars Sage and Vona and resistant cultivars Newton and Hawk was evaluated using symptomatology, the enzyme-linked immunosorbent assay (ELISA), and polyacrylamide gel electrophoresis. All three evaluations showed that resistant cultivars became infected by wheat soilborne mosaic virus, and symptoms were most pronounced during early jointing in February and March. In resistant cultivars, high ELISA values and high virus concentrations occurred later in the growing season than those in susceptible cultivars. Results from a study conducted in a growth chamber indicated that the late-season rise in ELISA values observed in resistant cultivars is related to tiller maturity rather than to sampling date.