Biocontrol effect of Penicillium oxalicum and Trichoderma asperellum on Ralstonia solanacearum

Key words: 
• Trichoderma asperellum /
• Penicillium oxalicum /
• Ralstonia solanacearum /
• fermentation broth /
• antibacterial effect

Abstract:   Objective  This study aims to investigate the effect of two biocontrol strains Trichoderma asperellum QZ2 and Penicillium oxalicum QZ8 on Ralstonia solanacearum (bacterial blight for short) With the help of T. asperellum QZ2 and P. oxalicum QZ8 screened by our laboratory, the effect of two biocontrol strains on R. solanacearum was investigated. Hereinafter referred to as the biocontrol effect of bacterial blight.  Method  Using bacterial blight as the target, The the inhibition effect of biocontrol bacteria and their fermentation broth on the growth of bacterial bacterial blight was determined by plate culture method and growth curve method. Soil culture test and dilution coating method were used to determine the inhibitory effect of biocontrol bacteria on bacterial blight in soil.   Result  In plate confrontation culture experiment, test showed that QZ2 and QZ8 had significant inhibitory effects on bacterial blight (P＜0.05), with inhibition rates of 80.9% and 45.9%, respectively. The plate culture with high temperature sterilized fermentation broth of QZ2 and QZ8 two biocontrol strains also showed significant inhibition effect on bacterial blight in plate culture (P＜0.05), and the inhibition rates of QZ2 and QZ8 on bacterial blight reached were 33.3% and 34.8%, respectively. The fermentation broth on the growth of bacterial blight results showed that the D(600) value of the treatment was significantly lower than that of the control (P＜0.05), and the inhibition effect of QZ2 was better than that of QZ8. Soil culture test results showed that the number of viable bacteria of R solanacearum in soil treated by with two biocontrol strains was significantly lower than that of ck (P＜0.05).  Conclusion  In this experiment, the biocontrol strains of QZ2 and QZ8, which were extracted independently, had have significant inhibitory effects on bacterial blight wilt, and could can be positioned identified as potential biocontrol bacteria of tomato bacterial wilt. [Ch, 5 fig. 2 tab. 32 ref.]