Investigation of Gamma Radiation Effects on Morphological and Antagonistic Characteristics of Trichoderma harzianum

In this study، effects of gamma irradiation doses on spore germination of Trichoderma harzianum and its effects on morphological and antagonistic capability of the mutants to control Rhizoctonia solani have been evaluated. Spore suspension of Trichoderma was gamma-radiated by 0، 50، 100، 150، 200، 250، 300، 350، 400 and 450 Gry Gamma ray and the effects on mycelial growth were evaluated by irradiation with 0، 400، 800، 1200، 2000 and 2500 Gry. The results obtained showed that 450 Gry gamma radiations completely blocked the spore germination and 250 Gry was found as the optimum dose to induce mutation in Trichoderma. Furthermore، gamma irradiation could change the morphological characteristics such as: colonies shape and color، sporolation and mycelia growth rate. Dual culture test proved that، the mutated isolates had statistically more antagonistic capability against R. solani than its parental strains. According to the findings of the present study، bio-control capability of Trichoderma could be improved through gamma radiation.