The Pgpr as Elicitors of Plant Defence Mechanisms and Growth Stimulants on Tomato (Lycopersicum esculentum Mill.)

In this study, the CAS agar plate assay for siderophores was used to screen bacteria from the rhizospheric soil of tomato in Annamalai nagar, Tamilnadu. As a result, Bacillus subtilis and Pseudomonas fluorescens, which produced a large orange halo, was obtained. A dual-culture test showed that both organisms strongly antagonized the growth of Fusarium oxysporum plant fungal pathogens, which rates of inhibition ranging from 25.59 to 93.45%. Analysis of the siderophore production by CAS agar plate assays showed that both organisms produced the siderophore. A pot culture experiment was analyzed to study the effects of P. flourecens and B. subtilis on pathogen development and plant growth. Both organisms reduced the incidence of Fusarium wilt in tomato significantly, by 79.69-75.24% which indicated that those organisms induced systemic resistance to Fusarium wilt in tomato. Iron supplementation reduced this biocontrol effect. There were significant increases in plant height, no. of fruits per plant, yield per plant and average fruit weight. This research showed that P. fluorescens B. subtilis has great potential for plant growth promotion and biological control for tomato disease.