Main action mechanism of biocontrol microorganisms on plant pathogenic nematodes:A review

Phytopathogenic nematodes are pathogenic microorganisms that infest a wide range of crops, causing huge economic losses to the production of many crops, and have become an important constraint to global food and vegetable security. The control of pathogenic nematodes has long relied on chemical pesticides, which has produced serious environmental pollution and food safety problems, and there is an urgent need for safe, green and efficient alternative strategies to chemical control. Biocontrol microorganisms are relatively friendly to the environment and are an effective alternative to chemical control. The article described the main species and feeding mechanisms of plant pathogenic nematodes, the main action mechanisms of different species of microorganisms on plant pathogenic nematodes and the latest research progress at home and abroad, and summarized the main mechanisms of action of biocontrol microorganisms on pathogenic nematodes, such as trapping, parasitism, production of antagonistic substances, competition for resources and space, and induction of plant self-defense response of pathogenic nematodes on the basis of the previous researches. Future research priorities were proposed. Antagonistic nematode biocontrol strains screened in the laboratory were inevitably affected by biotic or abiotic factors in field environments, which might reduce the effectiveness of control. Therefore, the stability and efficiency of biocontrol strains and related products applied under field conditions would be one of the major challenges ahead. Only a few commercial biocontrol products using microorganisms have been developed, and even fewer have been registered. The development of efficient, stable, and mature biocontrol fungicide-related products and their application in the market was also a problem that needed to be solved in the future. The action mechanism of microorganisms on nematodes is complex and varied, and the interactions between these factors are even more intricate and complex, which would also be the focus and difficulty of future research on the use of microbial resources for nematode control.