Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 8/13/1997
Publication Date: N/A
Technical Abstract: Fluorescent pseudomonad strains from the leaves of several plant species were tested for ability to control bacterial leaf streak (BLS) caused by Xanthomonas campestris pv. translucens (Xct). Seven days after spray inoculation of wheat seedlings with Xct at varying densities, BLS severity on the first seedling leaf was proportional to Xct inoculum density and Xct tpopulation density at 48 h. Time to symptom expression was also a functio of population density at 48 h. Putative antagonists were tested for their ability to significantly reduce Xct colonization and BLS severity by inoculating wheat seedlings with an antagonist 48 h prior to inoculation with Xct. Thirty-three percent of the antagonists were capable of significantly reducing the population size of Xct 48 h after inoculation. Of the successful antagonists, 83% significantly reduced disease severity. Variation among antagonists in ability to control BLS may reflect ability to reduce the infection probability of individual Xct cells and/or reduce both external and internal Xct populations on wheat leaves.