Antagonistic effect of Pseudomonas fluorescens isolates against Fusarium oxysporum f. sp. ciceris

Fusarium wilt of chickpea, caused by Fusarium oxysporum f. sp. ciceris, is one of the most important diseases of this plant in Iran. In order to control this disease biologically, fluorescent pseudomonas were isolated from the rhizosphere of chickpea plants and enumerated using King’S medium B (KB). Antifungal activity of 80 bacterial isolates against Fusarium oxysporum f. sp. ciceris was evaluated on KB and potato dextrose agar (PDA) media. Results revealed that from 80 isolates tested, 81.25% of isolates in KB and 94.37% in PDA showed the ability to inhibit fungal growth. There was a correlation between production of antifungal metabolites and disease reduction, however, no correlation was observed between Siderophore production and metabolite production. Under greenhouse conditions, results showed that only M2-15 isolate reduced Fusarium wilt of chickpea significantly, with the rest having positive effects on chickpea growth factors. In greenhouse experiment, M2-15 ، Pf-5 and K-15 isolates caused a significant increase in growth factors including dry and fresh root and shoot weights compared to control plants. Among isolates studied in this research, M2-15 decreased the severity of chickpea wilt under greenhouse conditions, significantly.