Phage cocktail inhibits bacterial canker of kiwifruit in the field and affects the phyllospheric bacterial community

Abstract:

[Background] Phage cocktails have been reported as biocontrol agent against the kiwifruit canker pathogen Pseudomonas syringae pv. actinidiae (Psa). However, little is known about the control effect of phage cocktail in the field and the effect of phage cocktail on the phyllospheric bacterial community of kiwifruit plants. [Objective] To explore the biocontrol effect of phage cocktail against kiwifruit canker in the field, and reveal the effect of the cocktail on the microecology of endophytic bacteria in the stem phyllosphere of kiwifruit. [Methods] The healthy kiwifruit plants were infected with Psa, and the incidence of bacterial canker after application of phage cocktail or copper preparation was recorded. The changes in the community structure of bacteria in kiwifruit phyllosphere were analyzed by high-throughput sequencing. [Results] Compared with the copper preparation, the phage cocktail significantly reduced the incidence of bacterial canker, changed the richness and diversity of bacteria in the phyllosphere, enhanced the stability of bacterial community, and improved the abundance of functional genes, thus restoring the bacterial community to the healthy state. [Conclusion] Phage cocktails exert the role of microecological regulation while killing pathogenic bacteria, demonstrating great application potential in the biocontrol of kiwifruit canker caused by Psa.