The reactions of Canadian spring wheat genotypes to inoculation with Claviceps purpurea, the causal agent of ergot

Abstract

Ergot, caused by Claviceps purpurea, can be a detrimental pathogen of wheat because the sclerotia of this fungus are toxic to animals and humans. The purpose of this work was to determine if currently registered Canadian wheat cultivars and experimental wheat lines differ in their reactions to C. purpurea and to determine if different classes of wheat [Canadian Western Red Spring (CWRS), Canadian Prairie Spring (CPS), Canadian Western Extra Strong (CWES), Canadian Western Soft White Spring (CWSWS), and Canadian Western Amber Durum (CWAD)] differ in their levels of resistance. Fifty-four wheat genotypes from different western Canadian classes of wheat were inoculated with a mixture of six isolates of C. purpurea and assessed for the number of sclerotia produced per spike and rated for sclerotial size produced and the amount of honeydew produced. In general, CWAD wheats produced significantly fewer sclerotia per spike and the CWSWS wheats had significantly smaller sclerotia. None of the classes differed in honeydew production. One CWAD genotype, 9260B-173A, had the fewest sclerotia, and the lowest ratings for sclerotial size, and amount of honeydew produced compared to the other wheat genotypes tested. Key words: Hexaploid wheat, durum wheat, Triticum turgidum var. durum, T. aestivum, ergot, Claviceps purpurea, resistance, sclerotia size, honeydew