INDUCTION OF MUTAGENESIS ON TRICHODERMA SP. TO ENHANCE ITS BIOCONTROL ACTIVITY AGAINST DIAPORTHE SP.

ABSTRACT

The study was aimed at investigating the outcome of subjecting Trichoderma sp.tomutagenesis using sodium azide and nitrous oxide chemical mutagens, in order to enhance its biocontrol activity against Diaporthe sp. Wildtype Trichoderma sp. which was collected from the stock culture collection of the Plant Pathology Division, Nigerian Institute for Oil Palm Research (NIFOR), Benin City was treated with sodium azide or nitrous oxide at 5, 10, 15, 20 min exposure time to induce mutation, while untreated Trichoderma served as control. They were plated on potato dextrose agar and incubated at 27^oC. After 4 days (for sodium azide) and 8 days (for nitrous oxide) of incubation, the mutated Trichoderma spp were individually co-cultured with Diaporthe sp. and incubated at 27^oC in order to investigate its biocontrol activities. For the co-culture with mutant Trichoderma treated with sodium azide, the wild type showed increased pathogenic growth with increase in the age of culture while the mutants showed both increased and decreased biocontrol activity on the pathogen. The co-culture with mutant Trichoderma treated with nitrous oxide showed almost similar results with that of sodium azide with the only difference being that staticity of pathogenic growth occurred with the mutant Trichoderma sp.In conclusion, it can be said that sodium azide and nitrous oxide can induce mutagenesis on Trichoderma sp. and this in turn enhances its biocontrol activity.