Xenorhabdus szentirmaii Bakteri Metabolitlerinin Bazı Önemli Bitki Patojeni Funguslara Karşı Antifungal Etkilerinin Belirlenmesi

Abstract

This study was carried out to determine the antifungal effects of the supernatant produced by the bacterium Xenorhabdus szentirmaii, which is associated with soil-inhabiting entomopathogenic nematodes, on important plant pathogenic fungi, Fusarium verticilliodes, Fusarium oxysporum f.sp lycopersici, Fusarium oxysporum f.sp radicis lycopersici, Botrytis cinerea, Sclerotinia sclerotiorum and Phytophthora nicotianae. The effects of 1, 3, 5 and 7% concentrations of the supernatant produced by X. szentirmaii bacteria on mycelium growth of the fungal pathogens was determined at 3, 7 and 14 days after application (dap). The effects of the supernatant on the formation of sporangia and the emergence of zoospores from the sporangium of Phytophthora nicotianae was also determined. According to the results of the study, the highest dose of the supernatant (7% concentration) prevented mycelium development of all tested pathogens. The effect of the supernatant decreased at 14 dap against F. verticilliodes, F. oxysporum f.sp lycopersici, F. oxysporum f.sp radicis lycopersici. The antifungal effect on S. sclerotiorum completely disappeared in 14 days whereas the effect continued even in 14 days against B. cinerea and P. nicotianae. Xenorhabdus szentirmaii supernatant at a concentration of 7% was highly efficacious on the formation of sporangia and the emergence of zoospores within the sporangium of P. nicotianae at a concentration of 7%.