Screening of fluorescent pseudomonad isolates against Sclerotium Rolfsii sacc, of soybean (Glycine Max)

An attempt was made to isolate and characterize Fluorescent pseudomonads from the rhizosphere soil samples and further screening of the isolates for their antagonistic properties against Sclerotium rolfsii Sacc, of soybean. The isolates were subjected for morphological, biochemical and functional characterization. All the isolates exhibited fluorescence under UV light. Cells were rods and gram negative. All the isolates produced clear zone of P-solubilization (TCP) (18.80–21.71 mm diameter) on Pikovskaya's agar medium. The fluorescent pseudomonads produced significantly varying quantities of IAA (19.97 µg to 28.89 µg IAA/25 ml of broth) and GA (18.52 µg per 25 ml broth). All the isolates showed antagonistic activity against Sclerotium rolfsii. The per cent inhibition ranged from 36.85 to 70.37. Under pot culture experiment, lowest PDI was observed in DFP48 followed by DFP47, among the FP isolates. These isolates also showed maximum peroxidase activity and also plant growth promotional activities.