Submitted to: American Chemical Society Symposium Series
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2001
Publication Date: 11/1/2004
Citation: Schisler, D.A., Khan, N.I., Boehm, M.J. Biological control of fusarium head blight of wheat and deoxynivalenol levels in grain via use of microbial antagonists. In Jackson, L.S., Trucksess, M.W., DeVries, J.W. Mycotoxins and Food Safety. American Chemical Society Symposium Series. p.53-69.
Interpretive Summary: Plant diseases not only reduce the yield of crops but, in some cases, the pathogen that causes the disease can produce toxins that reduce the quality of the crop. The fungus Fusarium graminearum infects wheat heads causing the disease Fusarium head blight (FHB). This disease costs farmers more than 3 billion dollars in yield and grain quality losses in the last 10 years in the U.S. Control options for this disease are limited. Although registered fungicides can be effective, residue and cost concerns are potential problems with fungicide usage. Highly resistant wheat varieties are not currently available for commercial use. We report on the discovery and development of seven microorganisms that can biologically control this disease in the greenhouse and in the field. Initial findings indicate that some of these microorganisms reduce disease in different ways, which may allow microorganisms to be combined into a product with increased effectiveness in reducing FHB. With these findings, we have taken an important step in developing a biological control product for use against FHB. With further research, we anticipate the development of these strains into one or more biocontrol products that could be used successfully in the integrated management of FHB.
Technical Abstract: Efforts to reduce mycotoxin contamination in food logically start with minimizing plant infection by mycotoxin producing pathogens. Fusarium graminearum (sexual stage, Gibberella zeae) infects wheat heads at flowering, causing the disease Fusarium head blight (FHB) and losses of over 2.6 billion dollars in the U.S. during the last 10 years. The pathogen often produces deoxynivalenol (DON) resulting in grain size and quality reduction. Highly resistant wheat varieties are not available for reducing FHB, and labeled fungicides are not consistently effective. We are evaluating the feasibility of biologically controlling FHB. Microbial strains from wheat anthers were screened for their ability to utilize a form of choline, a compound that stimulates early germ-tube growth of F. graminearum and is found in anthers, a primary infection site of the pathogen. Five strains that utilized choline bitartrate and two that did not were effective in reducing FHB disease severity by up to 95% in greenhouse and 56% in field trials. Additional research programs around the globe have identified other antagonist strains with potential for biologically controlling FHB. Though a considerable body of research remains to be completed, strategies and microorganisms for biologically controlling FHB have reached an advanced stage of development and offer the promise of being an effective tool that could soon contribute to the reduction of FHB severity and DON contamination of grain in commercial agriculture.