Effectiveness of Bacillus pseudomycoides strain for Biocontrol of Early Blight on tomato plants

Abstract

Alternaria early blight is an air-borne and soil-borne pathogen that cause losses and damages that can reach up to 80% in tomato production. In our work, the immediate antagonistic effect of Bacillus pseudomycoides was inspected against Alternaria early blight of tomato. Bacillus pseudomycoides (Bp1) (OQ629426) gave inhibition efficacy against A. solani growth, being, 74.22 %. Invitro, Bp1 had the capability to produce the endogenous plant auxin (IAA) it was 18.9 (µg/100 mL), the quantity of GA 9.4 (µg/100 mL), 95.8 μ Deferroxamine mesylate. Tomato plants treated with B. pseudomycoides registered the least disease severity, being 50 and 40 % in Mancozeb + ALS and Bp1+ ALS treatments with high efficiency to control the severity between 75 and 100 % respectively. Tomato plants treated with B. pseudomycoides showed improved growth characteristics as compared with the untreated control. Plants with bacterial treatment conferred 45.6 cm shoot length, 2.9 (g∕plant) fresh weight and 0.7 (g∕plant) Dry weight. The highest increase in the activity of polyphenol oxidase (PPO) and peroxidase (POD) was observed in the infected leaves of tomato plants treated with B. pseudomycoides Bp1 (T4) (4.6, 6.9 m/g f. w.) respectively, followed by treatment of plants with Mancozeb (T3) (3.9, 5.4 m/g f. w.) respectively, compared to other treatments. This study suggested that B. pseudomycoides is a promising biocontrol agent against Alternaria early blight. This bacterium may represent an important source of potential antimicrobial bio-agent against Alternaria early blight disease, also it may play a role in the development of integrated control programs in future studies.