Application of composite biological control agent in postharvest preservation of cherry tomatoes

Abstract

Biological control has become an increasingly important means of post-harvest disease control due to its green and efficient advantages. This approach is gaining growing attention from people. Here, a biocontrol bacterium capable of effectively antagonizing the Botrytis cinerea pathogen was isolated from the rhizosphere soil collected in Tibet, China. The strain was identified through physiological, biochemical, and taxonomic analysis as Bacillus subtilis XZA. We combined XZA with the biocontrol bacterium Bs-9 (Bacillus siamensis) preserved in our laboratory to form a composite biocontrol agent. To enhance the biocontrol efficiency of the composite agent, we identified the most suitable synergist. The results showed that the biocontrol effect of the composite agent was better than that of the single biocontrol agent, and it exhibited even better biocontrol effects after the addition of the appropriate synergist. After spraying the composite biocontrol agent, the water loss rate of post-harvest cherry tomatoes (S. lycopersicum var. cerasiforme) was reduced. Additionally, the biocontrol agent can form a biofilm on the surface of the tomatoes and secrete volatile antimicrobial substances, effectively preventing the occurrence of post-harvest tomato diseases. Therefore, this biocontrol agent has excellent application value and can be used for the biological control of post-harvest diseases in cherry tomatoes.