Identification of marine bacillus isolate Y3F suppressing fusarium wilt of cucumber

Abstract:

[Objective] An antagonistic bacterium Y3F is isolated from marine algae in Lianyungang, its biocontrol effect on cucumber fusarium wilt is studied. [Methods] Y3F is identified as Bacillus cereus through the morphological, physiological and biochemical characteristics and phylogenetic analysis based on 16S rRNA gene sequence. The antimicrobial activity of broth and sterile filtrate of Y3F is checked by plate confrontation method, and its biocontrol activity to fusarium wilt of cucumber is checked by pot experiments. [Results] Y3F is identified as a member of Bacillus cereus. The sterile culture filtrate of Y3F in 2216E medium strongly inhibit the growth of Fusarium oxysporum strain cfcc 82185, implying that Y3F might secrete some kinds antifungal substances. The results of pot experiments indicated that soaking seeds and irrigating roots treatment (JG) could significantly increase the production of cucumber biomass, lower the incidence rate of fusarium wilt disease up to 50.46% after planting 30 days, and increase the total number of bacteria and actinomycetes, and decrease the number of fungi and Fusarium oxysporum strain cfcc 82185 in rhizosphere soil. [Conclusion] Strain Y3F can effectively control fusarium wilt of cucumber and improve microbial community structure in rhizosphere, and it has potential development and application prospect.

Key words:Strain Y3F, Cucumber fusarium wilt, Antagonism, Biocontrol