Genetic Improvement of Native Trichoderma spp. for Carbendazim Tolerance for the Management of Macrophomina phaseolina Incitant of Charcoal rot of Sunflower

Carbendazim tolerance in native Trichoderma isolates was induced by exposing the culture to UV-irradiation for different periods viz., 0,2,4,6 and 8 hr and the same were grown on PDA amended with different concentrations of carbendazim viz., 0.01, 0.05, 0.1, 1 and 1.3% consequtively and tested for their stability. Mutant isolate TM₁₇ showed tolerance up to 1.3% of carbendazim while native isolate (TW₁₇) failed to tolerate even at 0.01% concentration. Mutant strain, TM₁₇ inhibited the mycelial growth of test pathogen by 90% when compared to corresponding wild type TW₁₇ (62.2%) indicating the enhanced antagonistic effect by genetic means.