Effect of Three Species of Rhizobacteria (PGPR) in Stimulating Systemic Resistance on Tomato Plants against Cucumber Mosaic Virus (CMV)

Abstract

This experiment aimed to study the effect of three species of plant growth promoting rhizobacteria (Frateuria aurantia, Bacillus megaterium and Azotobacter chroococcum) inoculated to seeds and shoots of tomato plants on Cucumber mosaic virusdisease severity, salicylic acid and peroxidase activity content and their ability to suppress the effect of CMV in a plastic tunnel in Tartus-Syria. The results showed that, the treatment with single bacteria Frateuria aurantia produced significant reduction in disease severity and higher infree salicylic acid and peroxidase activity contents compared with Bacillus megaterium or Azotobacter chroococcumin CMVinfected or healthy controls. Mixed treatments with three bacterial species gave the highest reduction in disease severity and increasedof free salicylic acid and peroxide activity contained in both CMV-infected and healthy tomato plants. Such increase in free salicylic acid and peroxidase activity contents suggested the potential ability of rhizobacteria to stimulate mechanisms of systemic resistance and reduces the effect of CMV infection on tomato plants.

Efficacy of Biotic and Chemical Inducers of SAR in Management of Plant Viruses

“…The result was observed as a significant reduction in disease severity and disease incidence. The analysis of the treated plants also showed high free salicylic acid and peroxide activity contents (Shami et al, 2017;Lee and Ryu, 2016;El-Borollosy et al, 2012). Tobacco treated with two different strains each of Bacillus subtilis and B. amyloliquefaciens showed a fair level of resistance induced against TMV.…”

“…It is to be noted that the antagonist in use may be a commercial formulation or culture filtrate obtained from cultures grown in suitable media. For commercial formulations, the standard dosage is to be followed (Raupach et al, 1996;Murphy et al, 2000;Wang et al, 2009;Shami et al, 2017).…”

“…This method has been found to be effective in greenhouse condition especially in potted crops. The irrigation is to be repeated every 3-4 days for about a period of 15 days (El-Borollosy et al, 2012;Shami et al, 2017). Many studies also indicate effective results on combined use of two or more of the above methods.…”