[Objective] The study aimed to study the antifungal activity of biocontrol strains against Alternaria mali,colonization ability in apple leaves and the impact of some chemical fungicides on biocontrol strains were also studied.[Method] Healthy leaves of Matsumotokin were collected to conduct vitro leaf test,colonization test and influence test of different fungicides on biocontrol strains.[Result] Vitro leaf test showed that B.subtilis BS-315 had strong inhibition effect on A.mali,when biocontrol strain was daubed on leaves,and pathogen was inoculated after 1 d,the inhibition effect of BS-315 against A.mali was over 90% after 3 d.BS-315 could colonize in leaves of Matsumotokin,colonization volume reached the maximum after inoculation for 3 d.Azoxystrobin and polyoxin had certain promoting effect on the growth of BS-315,while carbendazim and propiconazole completely inhibited the growth of BS-315.[Conclusion] This study would provide theoretical basis for development and rational utilization of biocontrol preparations.
