Host Genotype Effects on Inoculum Production by Cephalosporium gramineum from Infested Residue. P. A. Shefelbine, Former Graduate Research Assistant, Department of Plant Pathology, Kansas State University, Manhattan 66506-5502. W. W. Bockus, Associate Professor, Department of Plant Pathology, Kansas State University, Manhattan 66506-5502. Plant Dis. 74:238-240. Accepted for publication 22 October 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0238.

Five winter wheat (Triticum aestivum) cultivars differing in resistance to Cephalosporium stripe were inoculated with Cephalosporium gramineum, and the mature infested straw was placed under conditions conducive to sporulation of the fungus. Cultivars Dodge and Newton had a significantly greater percentage of straw segments showing sporulation of C. gramineum than cultivar Sturdy, and dilution plating indicated that residue from those cultivars produced more inoculum per gram of straw. Straw from Plainsman V supported the production of inoculum at a level similar to that observed for Sturdy, whereas straw from Arkan supported a level of inoculum midway between those of Sturdy and Newton. Inoculum production was not related to the resistance response of the cultivar: Sturdy is highly susceptible, and Newton and Plainsman V are moderately resistant. These results suggest that Cephalosporium stripe decline induced by monoculture of moderately resistant cultivars is not the result of reduced ability of the infested residue of these cultivars to produce inoculum.

Keyword(s): Hymenula cerealis.