Vol. 12, Issue 6 (2023)

Mutagenesis is one such technique that induces diversification of genotypes of targeted organisms. Mutagen induced changes could either be random or targeted based upon the suitable mutagenesis technique. Biocontrol-associated characters of mutants obtained by successful screening and analysis can be significantly improved. Genetic improvement of Trichoderma spp. By induced mutation using physical and chemical mutagens have been attempted successfully to ameliorate the efficacy of native strains. Such mutation brings about changes in various morphological features and different physical and biochemical attributes as well as potential increase in antifungal metabolites of the selected mutants as compared to their wild parents has also been observed. Certain mutants of Trichoderma spp. have been to have better rhizosphere competence compared to their parent strains. Selection of such beneficial mutants may be a better avenue for the management of plant pathogens.

In the present investigations, two best strains of Trichoderma i.e. UBT-18 and T21 were isolated from soil of Cooch Behar, West Bengal and placed under UV light with different duration of exposures. The colonies from individual mutated spores of Trichoderma strains were repeatedly sub-cultured in test tubes up to 10th generation to obtain stable mutants. Some Trichoderma strains died out before reaching last generation growth due to segregation effect after random mutation.