Endophytic fungus J7 prevents disease and promotes growth in .

The objective of this study was to evaluate the feasibility of using the endophytic fungus J7 as a biocontrol agent for blight, and to provide ideas for sources and practical applications of biocontrol agents. sp. J7 was isolated from L. and identified as . The growth inhibition capacity of J7 against , the cause of blight in was 90.0% in filtrate-modified plates, and the incidence of blight in potted plants was reduced by 14.8%, surpassing the 7.4% reduction in the positive control group treated with cymoxanil plus mancozeb. Strain J7 also significantly increased the fresh weight and height of potted seedlings by 2.39 and 1.37 times, respectively. Furthermore, within 5 months of inoculation, the tanshinone content in the field-grown increased significantly compared to control plants. Additionally, the mechanisms of growth promotion, antimicrobial activity, and regulation of secondary metabolites by strain J7 were explored, which strongly support the practical application of this fungal preparation in controlling blight.IMPORTANCE can cause various plant diseases, and currently available control methods are still limited. Existing species show certain limitations in the control of plant diseases caused by . This study confirms a promising biological control agent that can be used to control and provides additional information on the biological characteristics of .