Biocontrol potential of antagonistic bacteria strains against Fusarium oxysporum and their growth-promoting effects on zucchini

Abstract:

[Objective] In order to assess potential of plant growth promoting rhizobacteria (PGPR) for protecting zucchini plants against Fusarium oxysporum, antifungal properties and growth-promoting effects of PGPR were evaluated. [Methods] 19 strains that acquired from preliminary studies were used to antagonize F. oxysporum in vitro based on panel confrontation. Control efficiency of microbial inoculant was measured on zucchini root rot at greenhouse experiments. Growth-promoting effect of compound inoculant instead of some chemical fertilizer was determined at field tests. [Results] There were 9 strains efficiently antagonized F. oxysporum. Among these strains, the inhibition rate of strain FX2 could rise up to 66.80%. In greenhouse experiments, the inhibition rate of microbial inoculant (LHS11+FX2) reached 57.14%. In field experiments, microbial inoculant with different proportional chemical fertilizer had growth-promoting effect on biomass and root morphology, and the yield of 85% chemical fertilizer + compound inoculant significantly increased 27.13%. [Conclusion] The compound inoculant (LHS11+FX2) has excellent control efficiency to zucchini root rot. The growth-promoting effect of 85% chemical fertilizer + compound inoculant is obvious on the growth of zucchini, and it largely saves fertilizer costs and improves production efficiency.