Studies on strain improvement of predacious fungi: Generation of mutant strains by random mutagenesis

Random mutagenesis by chemical mutagenic agents, ethyl methane sulfonate and albendazole on wild isolates of nematode-trapping fungus Duddingtonia flagrans and egg parasitic fungus Verticillum chlamydosporium resulted in generation of mutant strains. The D. flagrans mutant generated by ethyl methane sulfonate exhibited dense white colonies while the mutant generated by albendazole and control exhibited thread like appearance with aerial mycelia growing vertically on the surface of the media. The V. chlamydosporium mutant generated both by ethyl methane sulfonate and albendazole and the control exhibited dark pigmented (creamy to light brown) colonies. The conidial and mycelial morphology of mutant strains varied widely with the control strain including their ability to produce chlamydospores in culture plates.