[Discussion on applications and mechanisms of biocontrol microoganisms used for controlling medicinal plant soil-borne diseases].

In recent years, the soil borne disease of medicinal plants becomes severely during the process of cultivation and directly endangered the production and quality of raw materials used in traditional Chinese medicine (TCM). The chemical pesticides have been constantly used to prevent and control the soil borne disease, but only a few are effective. Meanwhile, the excessive uses of chemical pesticides also lead pesticide residues in TCM, which often exceed limit of the standard, and harm the human health and cause environmental pollution. Therefore, biological control has become a hot research point for its environmental advantages. This paper mainly discussed the mechanisms of different species of microorganisms, which could control the soil borne disease of medicinal plants, from the following aspects: improving host plants' nutrient absorption, the nutrient and space competition with the pathogenic bacteria, changing the morphology and anatomical structure of roots, adjusting the host plants' endogenous hormones, restoring the balance of host rhizosphere soil microecology and activating the host plants' defense system etc. Then put forward the prospect of biocontrol agents in the future.