Bacillus thuringiensis strain 199 can induce systemic resistance in tomato against Fusarium wilt.

The research work was performed to investigate the potential of Bacillus thuringiensis strain 199 to induce systemic resistance in tomato against Fusarium wilt. Roots of two-week-old seedlings of tomato plants were primed with bacterial strain. After 10 days of transplantation, some pots of tomato seedlings were provided with inoculum of Fusarium oxysporum lycopersici according to experimental design to induce disease. After 15 days of incubation period, plants challenged with F. oxysporum lycopersici alone were having obvious symptoms of Fusarium wilt. Plants that were treated with B. thuringiensis 199 + F. oxysporum lycopersici were having significant reduction of disease severity. Quantity of total phenolics increased 1.7-fold in bacterial-treated plants as compared to nontreated. Likewise, in case of defense-related enzymes, a significant increase of 1.3-, 1.8-, and 1.4-fold in polyphenol oxidase (PPO), phenyl ammonia lyase (PAL), and peroxidase (PO) was observed in comparison with untreated control. These results, hence, prove the potential of this bacterial strain for use as plant protection agent.