Phage Cocktail Alleviates Bacterial Canker of Kiwifruit by Modulating Bacterial Community Structure in Field Trial

Bacterial canker of kiwifruit is the most destructive bacterial disease caused by Pseudomonas syringae pv. actinidiae. Bacteriophages are regarded as promising biocontrol agents against kiwifruit bacterial pathogens due to their exceptional host specificity and environmentally friendly nature. However, the underlying mechanism of phages in the control of kiwifruit bacterial canker disease remains elusive. In this study, the field trial results showed that phage cocktail could significantly reduce the incidence of bacterial canker in kiwifruit. The high throughput sequencing results showed that the phage cocktail regulated the impact of pathogen invasion on branch endophytic communities, adjusted the diversity of the bacterial community structure, regulated the composition of rare taxa and abundant taxa, and increased the proportion of deterministic processes in community assembly processes. The phage cocktail significantly reduced the relative abundance of Pseudomonadaceae, Pectobacteriaceae, and Yersiniacea. Furthermore, the application of the phage cocktail resulted in an increase in the relative abundance of Beijerinckiaceae, Sphingomonadaceae, and Xanthomonadaceae, most of which are abundant taxa of the corresponding microbial communities. Additionally, the composition of rare taxa was also altered under the influence of phages. These findings offer perspectives on the phage-mediated biocontrol of kiwifruit bacterial canker and provide practical backing for the implementation of phage cocktails in sustainable agriculture.