[Antibiotics production by bacterial agents and its role in biological control]

Using bacteria to control plant diseases is one of the main strategies in plant protection, and its mechanism is commonly thought to be the production of antibiotics by bacteria. The produced antibiotics not only have structural diversity, but also have broad-spectrum activity against many pathogens. Experimental results showed that one kind of antibiotics could be produced by several bacterial strains, and one bacterial strain could also produced more than one kind of antibiotics. Recent development in molecular and bio-analytical techniques greatly promoted the research of bacterial bio-control, and the colonization survey of introducing bacterial strain to the rhizosphere and spermosphere of host plants. Besides bacterial genotypes, several biotic and abiotic factors including whether the pathogens existing or not, temperature, pH, carbon and nitrogen sources are also identified to affect the antibiotics production by bacteria. The authors illustrated some of the impeding problems in bacterial bio-control agents' application, and suggested that in the future research, more attention should be paid on developing mixed bio-control agent to avoid the anti-antibiotic activity of pathogens.