Antagonistic Activity of Fluorescent Pseudomonads against a Polyphagous Soil Born Plant Pathogen–Sclerotium Rolfsii

Abstract

A total of 35 fluorescent Pseudomonad strains were isolated from forest litter of seshachalam hill range. Out of 35 bacterial isolates 19 were found to be antagonistic to Sclerotium rolfsii in in vitro conditions. The growth inhibition zone of Sclerotium by uorescent Pseudomonads on potato dextrose agar varied from 4-9 mm with an average of 6.2 mm. Among the isolated uorescent Pseudomonads PSTPT13 found to be most potential. All the 19 isolates were characterized morphologically, biochemically and functionally. The mechanism of fungal toxicity was also observed by the production of HCN, siderophore and cell wall degrading enzymes. In this study we observed fungistatic activity is mainly due to the production of HCN, Siderophore and protease enzyme. This is the first report on fluorescent Pseudomonads isolated from forest litter of Seshachalam hill range the first ever biodiversity reserve of India with antagonistic activity against Sclerotium.