Submitted to: National Fusarium Head Blight Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/9/2002
Publication Date: 12/9/2002
Citation: CORE, A.B., SCHISLER, D.A., HICKS, T.E., LIPPS, P.E., BOEHM, M.J. POPULATION DYNAMICS IN THE FIELD OF A BIOCONTROL AGENT FOR FUSARIUM HEAD BLIGHT OF WHEAT. NATIONAL FUSARIUM HEAD BLIGHT FORUM PROCEEDINGS. p. 61.
Technical Abstract: Gibberella zeae (anamorph Fusarium graminearum) is the major causal organism of Fusarium head blight (FHB) on wheat and barley. Wheat anthers are an important site of infection. Application of Crytococcus nodaensis OH 182.9 to wheat heads at the time of flowering reduces FHB. The goal of this research was to determine the ability of OH 182.9 to survive and possibly reproduce on the anthers in the field. Heads of the soft red winter wheat cultivar Freedom were marked to distinguish those that had extruded anthers and those that had no visible anthers. Cells of the yeast antagonist were produced and harvested after a 48-hour growth in a semi-defined liquid medium at 25ºC in 250 rpm and applied [1x10E+7 colony forming units (CFU)/ml] to thoroughly wet the wheat heads. Non-antagonist/buffer treated plants served as controls. Plots were mist irrigated twice daily from anthesis through early grain development. Anthers were collected for up to 10 days after inoculation and CFU per 100 anthers in 0.5 ml buffer were determined. Initial OH 182.9 populations on anthers, at day 0, were 2.6x10E+4 CFU/ml. OH 182.9 population increased to 2.1x10E+6 CFU/ml (80 times) by 6 days after applying the cell suspension. The yeast population was 2.2x10E+6 by 10 days after application. OH 182.9 populations were greater than those of control plants on the heads with exposed anthers and heads with no visible anthers at 6, 8, 10 days and 8 days, respectively after inoculation.