Bioactivity of two aquatic hyphomycetes against some plant pathogenic fungi

Harnessing microorganisms and their metabolites to prevent diseases, offers an alternative in disease management without facing the drawbacks of chemical control. Aquatic hyphomycetes, members of ‘Fungi Imperfecti’ are the prolific producers of secondary metabolites useful in medicinal, industrial, and agricultural areas. They are the major microbial element in aquatic ecosystem occurring as active colonizer of submerged decaying leaf litter. Bioactivity of two potential aquatic hyphomycetes was tested against three phytopathogenic fungi using ‘Dual Culture’ and ‘Agar Well Diffusion’ method. Aquatic hyphomycetes were identified on the basis of morphological characters through pertinent literature while the pathogenic fungal cultures were outsourced to Bio edge solutions, Bangalore for molecular using 18s rRNA sequencing for their species confirmation. C. aquaticum showed maximum percent inhibition against F. oxysporum (49.3%) while minimum percent inhibition against F. solani (14%) in case of dual culture method. In agar well diffusion method C. aquaticum showed maximum percent inhibition against F. oxysporum (46.8%) while minimum percent inhibition against R. solani (14%). B. rhombica showed maximum percent inhibition against F. oxysporum (34%) while minimum percent inhibition against R. solani (13.5%) in dual culture method. In agar well diffusion method B. rhombica showed maximum percent inhibition against F. solani (35.4%) while minimum percent inhibition against F. oxysporum (21%). The MIC of C. aquaticum was recorded to be 50 µg/ml against F. oxysporum and 25 µg/ml against F. solani and R. solani while MIC of B. rhombica was recorded to be 50 µg/ml against all the test fungi. Minimum Inhibitory Concentration and Activity index of hyphomycetous extracts indicated their potential more or less equivalent to that of Carbendazim, a commercial fungicide.