Optimal amount of Bacillus amyloliquefaciens FH1-RS1 and Bacillus cereus R19 to inhibit the growth of Verticillium dahliae

Abstract

Biological control of Verticillium wilt caused by Verticillium dahliae is a green and sustainable strategy. However, the antifungal activities of different amounts of biocontrol bacterial are still not understand. This study investigates the antifungal activity of different amount of Bacillus amyloliquefaciens FH1-RS1 and Bacillus cereus R19 against Verticillium dahliae V991 by dual culture plate. The results showed that both the fungal inhibition rate (FIR) and far fungal inhibition rate (FFIR) of B. amyloliquefaciens FH1-RS1 elevated with the increasing volume. The highest FIR (77.78%) and FFIR (58.33%) of B. amyloliquefaciens FH1-RS1 were both in 22 μL volume (7.2 × 108 CFU/mL). The highest FIR of B. cereus R19 was 48.15% in 12, 18 and 20 μL volume (1.2 × 108 CFU/mL). The highest FFIR of B. cereus R19 was 38.89% in 6 μL volume. This suggests that not all biocontrol bacteria have higher antifungal activity in higher amounts.