Screening of Pseudomonas sp. isolated from rhizosphere of pea plant as plant growth promoter and biocontrol agent

Plant growth promoting rhizobacteria (PGPR) are a heterogeneous group of bacteria that are found in the rhizosphere and rhizoplane which can improve plant growth. Pseudomonas spp. is one of the most promising groups of PGPR which can control plant pathogenic microbes in the soil. In this study, an attempt was made to isolate Pseudomonas spp., a potent PGPR in the rhizosphere. Through appropriate microbiological and biochemical methods, the study demonstrated the presence of fluorescent and nonfluorescent Pseudomonads in the rhizosphere of pea. 12 different strains of Pseudomonas were isolated from pea rhizosphere and identified by biochemical tests. Out of these strains five were screened against wilt and root rot pathogens of pea. Antagonistic activity of Pseudomonas isolates were evaluated against wilt and root rots pathogens i.e. Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum through dual culture technique. The study exhibited that all Pseudomonas strains significantly inhibited the growth of Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum as compared to control. Among all the Pseudomonas isolates Ps5 showed maximum inhibition against Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum. Augmentation of such PGPR will ensure a healthy micro climate for pea.