Control effect of Phlebia acerina MY51 on blueberry gray mold and its impact on interfoliar microorganisms

• The pathogen Botrytis cinerea causes gray mold disease on blueberry seedlings. • Phlebia acerina has a strong inhibitory effect on blueberry gray mold • Antibiotic present in the Phlebia acerina strain’s non-volatile metabolites. • Phlebia acerina alters the activity of defense enzymes in blueberry seedlings. • Strain change the phyllosphere microbial community of blueberry seedlings. Blueberry gray mold is caused mainly by Botrytis cinerea. We isolated a strain of Phlebia acerina MY51 from blueberry fungi, which showed a potent inhibitory effect on B. cinerea . Our study revealed that MY51 wrapped B. cinerea hyphae, causing deformation and exhibiting strong broad-spectrum antifungal effects. The mycelium of B. cinerea was significantly inhibited by volatiles, broth metabolites and the dual culture combined with the MY51 strain, with inhibitory rates of 47.67%, 39.33% and 46.10%, respectively. Twelve known antibacterial metabolites were detected in the methanol extract of its fermentation broth. In the pot experiment, MY51 significantly enhanced disease resistance, achieving an efficacy of 73.42%, against blueberry gray mold in addition to its capacity to stimulate growth. In the control experiment, different inoculation sequence treatments resulted in remarkable control effects of 76.96% and 70.89%, respectively. Upon MY51 inoculation, the activities of CAT, SOD, POD, PPO, and PAL significantly decreased in comparison with those in the CK. With the first and subsequent MY51 injection, the enzyme activity increased by 1.66%, 136.90%, 23.87%, 38.95%, and 96.61% and 15.69%, 32.50%, 20.00%, 196.25%, and 84.29%, respectively. Significant alterations in the blueberry interfoliar microbial community were caused by MY51 inoculation. Reference databases were used, and taxonomy annotation was conducted. The main microbial phyla identified were Ascomycota, Basidiomycota, Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Most of the bacteria and fungi present are considered beneficial, such as Trichoderma , Aureobasidium , Vishniacozyma , Alcaligenaceae , Bacillu s, and Pseudomonas . In conclusion, MY51 can considerably reduce blueberry gray mold outbreaks and offers fresh approaches for field management.