Biological Control of Damping-Off of Tomato Seedlings and Cucumber Phomopsis Root Rot by Bacillus subtilis RB14-C

Abstract

Bacillus subtilis RB14-C, which is a streptomycin resistant mutant of B. subtilis RB14 isolated from compost, produces an antifungal peptide, iturin A, and was evaluated for its suppressive ability against damping-off of tomato seedlings and Phomopsis root rot of cucumber. In damping-off disease of tomato seedlings caused by Rhizoctonia solani, RB14-C cell suspension treatment did not suppress the disease occurrence whereas germinated seed treatment of the RB14-C cells reduced the occurrence of the damping-off. In both treatments, iturin A could not be detected from the treated soil. In the Phomopsis root rot of cucumber, root immersion treatment of cucumber seedlings with RB14-C cell suspension at the time of transplanting effectively suppressed the root rot, resulting in growth recovery 50 days after the treatment even though the initial growth was retarded due to the Phomopsis infection. These results suggest that germinated seed treatment of RB14-C cells and root immersion treatment with RB14-C cell suspension can be applied as promising biological control practices of the dampingoff of tomato seedlings and the cucumber Phomopsis root rot, respectively.

In Vitro Evaluation of Antagonistic Microorganisms for the Control of Die-Back of Neem Causal Agent Phomopsis Azadirachtae

“…Studies on the effect of ethyl acetate extract on mycelial weight, pycnidial number and germ tube length of the pathogen revealed that both bacterial extracts were highly effective in suppressing growth of the pathogen. Biological control activity of B. subtilis and Pseudomonas spp., against several Phomopsis species was reported (Cubeta et al 1985;Fuchs and Defago 1991;Kita et al 2005;Maurhofer et al 1992). P. aeruginosa was employed as active biocontrol agent against many plant pathogens (Anjaiah et al 2003;Krishna Kishore et al 2005;Siddique and Ehteshamul-Haque 2001).…”

Antifungal efficiency of a lipopeptide biosurfactant derived from Bacillus subtilis SPB1 versus the phytopathogenic fungus, Fusarium solani

“…Accordingly, lipopeptides produced mainly by Bacillus species are very popular as antifungal agent to suppress plant tomato disease development (Ongena and Jacques 2008). Kita et al (2005) discussed the suppressive ability of iturin A produced by B. subtilis RB14-C against the dampingoff of tomato seedlings caused by R. solani and Phomopsis root rot of cucumber. A mycosubtilin from a B. subtilis overproducing strain was effective for reducing a Pythium infection of tomato seedlings marked by a significant increase in the germination rate of seeds with a greater fresh weight of emerging seedlings (Leclère et al 2005).…”

“…Also,Kita et al (2005) evaluated the suppressive ability of iturin A isolated from B. subtilis RB14 against damping-off of tomato seedlings and Phomopsis root rot of cucumber. Biosurfactant-type lipopeptides are involved in the multifaceted biocontrol potential of B. subtilis species against fungi spread and infection.…”

Lipopeptide surfactants: Production, recovery and pore forming capacity

“…TheAspergillus spp. and Biopolaris sorokiniana enabling its use as biocontrol agent[157].Kita et al [158]. discussed the suppressive ability of Iturin A produced by B. subtilis RB14-C against the damping-off of tomato seedlings caused by R. solani and Phomopsis root rot of cucumber.…”