In vitro antagonistic activity of fluorescent Pseudomonas isolates against Rhizoctonia solani and Sclerotium rolfsii

Abstract

Fluorescent Pseudomonas as a biocontrol agent offers a promising alternative to manage soil borne plant pathogens. However, the production of an antimicrobial compound varies among cultivars of the same species, and this has hampered the commercialization (Notz et al., 2001). Secondary metabolites produced by fluorescent Pseudomonas play key roles in the suppression of various soilborne plant pathogens. However, the performance of this biocontrol agent varies depending on the environment and host plant species. In this study, In vitro antagonistic activity against phytopathogens by fluorescens Pseudomonas of the 5 isolates of Pseudomonas showed different rates of growth inhibitions of R. solani and S. rolfsii, ranging from 39.995 to 65.275% and 34.995to 68.325% respectively. Based on percentage of inhibition radial growth values, the antagonistic isolates in decreasing order were P141> P200> P66> P229> P260 and P66> P200> P141> P229> P260 against R. solani and S. rolfsii respectively The isolates P141 and P66 were found to have the maximum inhibiting effect on the growth of R. solani (65.275%) and S. rolfsii (68.325%) respectively.