Enhancement in chitinase gene of Trichoderma harzianum by induced mutation with gamma radiation

Trichoderma spp. is considered as promising biological control agents. Antagonistic Trichoderma species control numerous of plant pathogenic fungi. The highest value of degrading enzymes production (chitinases and glucanases) between known micro- organisms belongs to this genus. Hence that chitinases have effective role in myco-parasitism mechanism of plant pathogenic fungi، therefore superior bio-control potential may then be found in isolates which produce a high capacity of these enzymes. Application of genetic engineering and direct mutation in fungal genome in order to increase T. harzianum antagonistic potential via enhancement in chitinase activity has some advantages. In this study، we use 250 Gry gamma irradiation dose to induce mutation in T. harzianum. Then، chitinase activity of 20 mutants have been evaluated and 15 mutants showed higher enzyme activity than wild type isolate. Thus، induced mutation by gamma irradiation in order to improve antagonistic capacity of native iranian Trichoderma spp. to obtain effective and useful bio- control agents is advisable.