|Khan, Naseem - OHIO STATE UNIV|
|Boehm, Michael - OHIO STATE UNIV|
Submitted to: Annual National Wheat Industry Research Forum
Publication Type: Proceedings
Publication Acceptance Date: February 10, 2000
Publication Date: N/A
Technical Abstract: Fusarium head blight (FHB), also known as scab of wheat, is a disease of major importance in humid and semihumid regions of the world. From among microorganisms obtained from wheat flowers, we selectively screened for antagonists that might reduce FHB. Wheat anthers were collected throughout Illinois and Ohio and more than 700 microbial strains obtained. Isolates from anthers were screened for their ability to utilize the anther compound choline, which stimulates germ-tube growth of Fusarium graminearum. In greenhouse tests, seven microbial strains reduced FHB, including five choline utilizers, and were selected for further study. In assays against F. graminearum isolate Z3639, six of the seven antagonists reduced disease as indicated by increased 100 kernel weight of microbially treated wheat heads. Bacterial strains AS 43.3, AS 43.4, and yeast strain OH 182.9 reduced disease severity by >77%, 93%, and 56%, respectively. On durum wheat cultivar Renville, selected antagonists reduced FHB in greenhouse tests with bacterial antagonist AS 43.3 decreasing disease severity by >90% and disease incidence by >75%. When antagonist cells and pathogen inoculum were sprayed onto wheat heads, all antagonists significantly reduced disease severity, regardless of the sequence, timing, and concentration of inoculum application. In field tests at Peoria, Illinois, five of six antagonists reduced FHB disease on soft red winter wheat cultivar Pioneer 2545 at one or both of the concentrations assayed. On moderately resistant cultivar Freedom, all six antagonists reduced FHB disease at one or both concentrations. Antagonists were also effective at the Wooster, Ohio, field site. Biological control shows great promise as part of an integrated pest management program for managing FHB.