Objective In order to obtain strains with antagonistic activity against F. solani, from healthy passion fruit root soil, conduct relevant characteristic studies, and provide new bacterial resources and theoretical basis for the biological control of this disease.

Method Healthy soil samples of passion fruit roots were isolated. Antagonistic bacteria were screened using confrontational culture method, and F. solani as the target stain to screen antagonistic bacteria. Morphological observation and molecular identification were performed on the obtained antagonistic strains to determine their classification status. And extracellular enzyme detection plates were used to determine their antagonistic and biocontrol abilities, and tomato seeds were validated for their growth promoting ability.

Result The research results showed that 8 strains of bacteria with antagonistic effects were isolated from 7 different soil samples, among which NN-Q03-10, SL-Q02-05, and SL-Q02-06 had the best inhibitory effect on the pathogen, its inhibition rates of 57.81%, 57.34%, and 57.34%. The classification status of the strains belongs to B. subtilis (4 strains) and B. velezensis (4 strains).8 strains of bacteria have the ability to produce proteases, cellulases, β-1,3-glucanases, and xylanases, the genome contains bacA, FenB, and yanJ antibiotic genes, while strains SL-Q02-05, NN-Q03-01, NN-Q03-09, and NN-Q03-10 also contain MycB and ifuA antibiotic genes.

Conclusion This study obtained a total of 8 strains with antagonistic activity, which can produce protease, cellulase, β- 1,3-glucanase, and xylanase. Some strains genomes were detected containing 5 antibiotic related genes, including mycB, ituA,FenB, bacA, and yndJ, indicating good biocontrol potential.