Identification and Inhibitory Effects of Antagonistic Bacteria Against Strawberry Root Rot（Fusarium oxysporum）

In order to screen antagonistic bacteria against Fusarium root rot of strawberry,totally 436 bacterial strains were isolated from strawberry rhizosphere soils.Three strains(w-25,w-79,w-181)were found to have high antifungi activities to Fusarium root rot of strawberry using five-point confrontation method,with inhibition zone of 11.0,5.4 and 6.4 mm,respectively.In addition,the three antagonistic bacteria on strawberry botrytis(Botrytis cinerea),strawberry red column pathogens(Fragria ananassa) and strawberry gum spore anthrax(Colletotrichum gloeosporioides)have high antagonistic effect.According to their physiological and biochemical characters as well as 16S rDNA sequences,w-25 was probablely identified as Pseudomonas fluorescens,and w-181 and w-79 were probablely identified as Bacillus subtilis.Antagonistic bacteria(w-25,w-79 and w-181)can inhibit the mycelium growth.Their metabolic products treatment can lead fungi mycelium abnormality,bioplasm condensed and cellularvacuole increased,which was observed using light microscope and transmission electron microscopy.