RESUMEN
The antagonism of two strains B1 and B2 of Bacillus spp. against pea root rot pathogen Fusarium oxysporum f. sp. pisi was studied. The result of pairing culture showed that B1 and B2 strains of Bacillus spp. had strong antifungal activity to the pathogen. The colonial color of the pathogen changed from gray to white, aerial hyphas increased and entangled into group after treatment with the cell-free fermentational filtrate of B1 or B2. Observation under optical microscope showed that hyphas and spores of the pathogen swelled and distorted with concentrated cytoplasm after treatment, the spores could not germinate or germinated abnormally . A lot of vesicles appeared at the top of the hyphas, and the hyphas stopped growing and broke finally, their cytoplasm spilled from the cell. The cell-free fermentational filtrate of B1 or B2 strains contained 1795.53?g/mL and 1345.93?g/mL protein respectively, from which two antifungal proteins of 103.5 kD (B1 ) and 127.6 kD (B2) were purified.