Biocontrol of Lysobacter enzymogenes CQ18 against the tobacco powdery mildew fugus, Erysiphe cichoracearum

Abstract Background Powdery mildew is a common leaf disease of crops worldwide. A large quantity chemical fungicides used to control this in horticulture and agriculture, producing serious safety environmental problems. To suppress safe environment-friendly ways, the biocontrol self-isolated new strain Lysobacter enzymogenes (CQ18) was studied against flue-cured tobacco powdery mildews. Results L. CQ18 produced chitinase, protease, β-1,3-glucanase, phosphatase, siderophore, which may enable bacterium degrade pathogen cell membranes walls deprive pathogens iron. HPLC/MS analysis identified 14 antifungal metabolites present fermentation liquid (LEFL), were grouped into organic acids, azoles, pyrimidines. The variable targets or on cells combinative effects these multiple potently be less likely make Erysiphe cichoracearum develop resistance. LEFL rich L-pyroglutamate. Both L-pyroglutamate inhibited germination E. conidia vitro reduced index greenhouse field. L-Pyroglutamate at concentration 0.50% achieved same efficacy as fungicide triadimefon (91–94%). Conclusions metabolite effectively controlled mildew. grows rapidly resilient adversity. has no toxicity humans easy synthesize low cost. show potential use controlling plant Graphical