Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2005
Publication Date: May 1, 2005
Citation: Desjardins, A.E. 2005. A role for ascospores in wheat head blight epidemics [abstract]. American Phytopathological Society. 95(6):S124. Technical Abstract: The Ascomycete Gibberella zeae (asexual state Fusarium graminearum) causes serious epidemics of wheat head blight worldwide and contaminates grain with trichothecene mycotoxins that are harmful to human and animal health. Anecdotal evidence dating back to the 19th century indicates that G. zeae ascospores (sexual spores) are a more important inoculum source than are macroconidia (asexual spores), although the fungus can produce both types of spores during wheat head blight epidemics. To study the role of ascospores in the biology of G. zeae, we previously generated fungal strains that are genetically identical and differ only in the presence of the mating type (MAT1)locus, which controls sexual development and ascospore production. In this study, we use these mutants to demonstrate that ascospores, but not macroconidia, play a critical role in epidemics in agricultural fields, at least in Illinois. Thus, the G. zeae sexual cycle is a new potential target for control of wheat head blight.