Co-inoculation of an Antibiotic-Producing Bacterium and a Lytic Enzyme-Producing Bacterium for the Biocontrol of Tomato Wilt Caused by Fusarium oxysporum f. sp. lycopersici

Abstract

The antifungal compound 2, 4-diacetylphloroglucinol-producing bacterium, Pseudomonas fluorescens strain LRB3W1, inhibits the growth of Fusarium oxysporum f. sp. lycopersici, and controls Fusarium wilt of tomato caused by F. oxysporum f. sp. lycopersici. On the other hand, Serratia marcescens strain B2, which produces cell wall-degrading enzyme chitinases, did not inhibit fungal growth and the suppressive effect of strain B2 against tomato Fusarium wilt was less than that of strain LRB3W1. Combined inoculation of strain LRB3W1 with strain B2 was more effective than treatment with strain LRB3W1 alone. When 2, 4-diacetylphloroglucinol and the chitinolytic enzymes were applied in combination, a synergistic inhibitory effect against the pathogen was observed. It was possible that bacteria which produce cell wall-degrading enzymes enhanced the biocontrol effect of the antibiotic-producing bacterium against tomato Fusarium wilt.