Abstract: Bacteria were isolated and screened from the rhizosphere soil of healthy pepper to obtain antagonistic strains with strong inhibitory effect on Phytophthora capsici. This study aimed to provide a basis for utilization of biocontrol strains. Antagonistic strains were screened out by spread plate and dual culture method. Strains were identified by morphological, physiological and biochemical characteristics, and 16S rDNA sequences analysis. The biocontrol potential was determined by pot experiment. IBFCBF-4 was isolated from the soils, which showed strong inhibitory effect on P. capsici. And it also had strong antagonistic effect against other eight kinds of plant pathogens. This bacterium was identified as Bacillus subtilis by methods described above. Pot experiment showed the control efficiency was 64.28% on P. capsici, and the fresh weight of shoot and root increased by 45.2% and 34.3%, respectively, when compared with the control group. IBFCBF-4 had a strong biocontrol effect on P. capsici and a significant growthpromoting effect on pepper; it was of great development and utilization value for P. capsici control in the field.

Key words: net ecosystem CO₂ exchange, meadow wetland, moisture, Horqin, temperature