The impact of γ-radiation on morphological characteristics and antagonist potential of Trichoderma harzianum against Rhizoctonia solani

Trichoderma harzianum was isolated from soil and its spore suspensions were irradiated in different dose of γ-radiation (0-400 Gy) for induced mutation. Dose of 250 Gy γ-radiation approximately results in 43.4% the inhibition of spore germination and this dose selected for optimum dose of induced mutation in Trichoderma. The T. harzianum mutants were selected based on potential growth on selective medium and their morphological characteristics and antagonistic activity against pathogenic fungi of Rhizoctonia solani have been evaluated. The results showed that γ-radiation could change the morphological characteristics like: colonies shape, color, sporolation and mycelia growth rate. Trichoderma mutants of T. h M8, T. h M16 and T. h M13 maintained higher ability to restrict R. solani. The study clearly showed the possibility of improving the antagonistic capability of Trichoderma for biological control of plant diseases through mutation with γ-radiation.

Keywords:

γ-radiation , Trichoderma harzianum , R.solani , bio-control , mutation