The objective of this study was to evaluate antifungal effect of water-soluble
chitosan (s-
chitosan) on Macrophomina phaseolina (M. phaseolina) causing jute seedling
infection and monitor the change in activity of released
enzymes during
infection. The minimum inhibitory concentration (MIC) of s-
chitosan for M. phaseolina was found at 12.5g/l and s-
chitosan exhibited fungistatic mode of action against this pathogen. The application of s-
chitosan (12.5g/l) during
infection of jute seedlings by M. phaseolina inhibited
fungal infection and length of the seedlings was found almost similar to seedlings without
infection. M. phaseolina infected jute seedlings showed length of 22mm over 10 days of incubation and it increased to 58mm in presence of s-
chitosan (12.5g/l) during incubation for 10 days. TEM study indicated presence of hyphae in the cortical and epidermal cells of fungus infected jute seedlings indicating colonization by the fungus and it disappeared
after treatment with s-
chitosan. The changes in
enzyme profiles of jute seedling during prevention of
fungal infection using s-
chitosan helped in proper understanding of mode of action of s-
chitosan as
antifungal agent. The activity of defense related
enzymes like
chitosanase and
peroxidase in infected seedlings was observed to be enhanced
after treatment with s-
chitosan.