INTEGRATION OF ENHANCED BIOCONTROL EFFICACY AND FUNGICIDE TOLERANCE IN TRICHODERMA SPP. BY ELECTROFUSION

Two species of Trichoderma, T. harzianum 1 and T. longibrachiatum were selected for strain improvement from 10 isolates of various habitats, for biocontrol capability against five important phytopathogens and d ual tolerance to copper sulphate and carbendazim, respectively. Electr ofusion using the protoplasts of the two isolates was effective at 120 V/cm, with a frequency of 1 MHz and an application of three DC pulses for 1 s at regular intervals, led to the successful recovery of fusio n products with a high fusion frequency (1.61). There was a slight enh ancement in the fusion frequency (1.70) in the presence of polyethylen eglycol (PEG). From the numerous fusion progeny that resulted, EF1 (in the absence of PEG) and EF2 (in the presence of PEG) were selected an d checked for the stability of their integrated characters from the pa rent strains.