Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 8/31/2000
Publication Date: N/A
Interpretive Summary: N/A.
Technical Abstract: Six transposon mutants of E. cloacae strain 501R3 were used to determine if if the total catabolic capabilities of this bacterium were required for beneficial activities in cucumber and pea spermosphere. Strain A-11 is diminished in general carbohydrate catabolism. Strains M-2, M-5, M-59, M-64, and M-83 are decreased in utilization of amino acids. Seeds treated with individual bacterial strains (10**9) cfu/seed) were sown in potting mix for seed colonization assays or in potting mix infested with sporangia of Pythium ultimum for biocontrol assays. Strain 501R3 effectively suppressed P. ultimum damping-off of cucumber but not of pea. All mutants had similar (P > 0.05) stand and plant weight / pot to strain 501R3. In addition, colonization profiles of all strains were similar on cucumber and pea seeds. These data demonstrate that the total catabolic capabilities of E. cloacae are not required for beneficial activities of this bacterium in cucumber or pea spermosphere.