In vitro effect of Bacillus spp. on Alternaria alternata infecting wheat

Abstract

Species of the genus Alternaria are significant wheat contaminants during production, transport and storage, requiring biocontrol measures which typically rely on the bacteria from the Bacillus genera. As these are among the most beneficial and exploited biocontrol agents, in this study, the inhibitory activity of indigenous Bacillus spp. was as?sessed against the Alternaria alternata isolate originating from the wheat seed. Two of the fifteen Bacillus s pp. i ncluded i n t he s tudy s howed t he i nhibitory effect. Specifically, 25.0?55.0% inhibition of A. alternata growth was achieved when the isolate coded as NB11 was applied in 106?109 cells mL-1 concentrations. On the other hand, when applied in 107?109 cells mL-1 concentrations, the isolate coded as NB16 inhibited A. alternata growth by 35.2?51.1%, but was ineffective at lower concentrations. Thus, these in vitro assays indicate that both Bacillus spp. (NB11 and NB16) isolated from the wheat rhizosphere can be applied in practice in the control of A. alternata.