Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/29/2001
Publication Date: N/A
Technical Abstract: Fusarium Head Blight (FHB) threatens the U. S. economy causing losses in the 1990s of more than $3 billion. Reduction of FHB using microbial antagonists has been demonstrated. Biomass accumulation by Gibberella zeae was quantified relative to glucose for 27 carbon sources using shake flask culture. Acetic acid, uridine, D-galactonic acid gamma-lactone, D-serine and gluconic acid supported only 0.9,1.0,1.1, 13.3, and 48.6 %, respectively, of the growth shown by G. zeae on glucose (P = 0.05). These 5 carbon sources were then assayed for ability to support biomass accumulation by rifampicin marked Bacillus subtilus AS 43.3 R1. Uridine supported growth of AS 43.3 R1 at 89% of that on glucose and was chosen as a formulation ingredient to stimulate antagonist colonization of wheat heads and efficacy. The population of AS 43.3 R1 varied considerably between experiments, but over 72 h it made up 54% of the total recoverable organisms versus 60% when formulated with uridine. AS 43.3 R1 reduced FHB (P = 0.05), but uridine did not influence biocontrol efficacy.