Investigation of gamma irradiation on morphological characteristics and antagonist potential of Trichoderma harzianum against M. Phaseolina

Trichoderma harzianum was isolated from soil and its spore suspensions were irradiated indifferent dose of γ-radiation (0-400 Gy) for induced mutation. Dose of 250 Gy γ-radiationapproximately results in 43.4% The inhibition of spore germination and this dose selected foroptimum dose of induced mutation in Trichoderma. The T. harzianum mutants were selectedbased on potential growth on selective medium and their morphological characteristics andantagonistic activity against pathogenic fungi of Macrophomina phaseolina have been evaluated.The results showed that γ-radiation could change the morphological characteristics like: coloniesshape, color, sporulation and mycelia growth rate. Trichoderma mutants of T. v M6, T. v M13and T. v M21 maintained higher ability to restrict M. phaseolina. The study clearly showed thepossibility of improving the antagonistic capability of Trichoderma for biological control ofplant diseases through mutation with γ-radiation.

Keywords:

γ-radiation , Trichoderma harzianum , M. phaseolina , bio-control , mutation