Abstract:In order to confirm the potential of antagonists for biological control against Verticillium dahliae, 154 actinomycetes which can decompose cellulose were isolated from the soil of Yan’an District and Hanzhong District of Shaanxi Province in China. The plate-confrontation method and growth speed rate method were used for preliminary screening and antimicrobial test in vitro. Pots trails were carried out to assess the inhibitory activity of strain ZX-10-4 in vivo. The taxonomic identification of strain ZX-10-4 was studied through its morphology, culture characteristics, chemotaxonomic tests and 16S rDNA sequence alignment. Results showed that 17 strains of actinomycetes exhibited good and stable inhibition activity against V.dahliae, and ZX-10-4 showed 90.15% inhibition rate. The protective and the therapeutic efficacy of the aseptic filtrate of ZX-10-4 reached to 70.00% and 60.33% with no dilution, and more than 50% in 5 times dilution in pots trails, respectively. Based on the identification methods used, strain ZX-10-4 was grouped into the genus Streptomyces and identified as a similar species to S.albireticuli.