Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/13/2005
Publication Date: 12/11/2005
Citation: Schisler, D.A., Boehm, M.J., Lipps, P.E., Slininger, P.J. 2005. USDA-ARS and the Ohio State University Cooperative Research: Greenhouse and field tests of combinations of choline metabolizing strains and antagonists Cryptococcus nodaensis OH 182.9 for reducing FHB of wheat. National Fusarium Head Blight Forum Proceedings. p. 232-235.
Technical Abstract: Combinations of two or more microbial antagonists enhance the efficacy and consistency of biocontrol in a variety of pathosystems. Choline and betaine, compounds found in wheat heads and anthers, stimulate germ tube growth of the Fusarium head blight (FHB) pathogen Gibberella zeae. Prior to the present studies, yeasts and bacteria were isolated from wheat anthers. Several choline metabolizing strains (CMS), discovered from this collection of microbial strains, reduced FHB in greenhouse and field trials. To test microbial combinations composed of several CMS and the non-CMS yeast antagonist Cryptococcus nodaensis OH 182.9 (NRRL Y-30216), biomass was first produced in a semi-defined liquid culture medium. Fully colonized broths were then diluted to one-quarter strength. Combining CMS antagonists with C. nodaensis OH 182.9 resulted in significant FHB reduction and a modestly enhanced disease reduction effect compared to OH 182.9 alone in repeated greenhouse trials. In field tests of combinations of OH 182.9 and CMS antagonists conducted in Wooster, Ohio, in 2005, OH 182.9 alone or in combination with CMS significantly reduced FHB severity to the same extent as the fungicide Folicur 3.6F on wheat cultivar Freedom but not significantly on cultivar Elkhart.