Molecular characterization of soilborne trichoderma spp. isolates and determination of its biocontrol activity

In this study, we aimed to determine the growth at different temperatures, spore-forming, temperature tolerance of spores, antifungal and antimicrobial activity, resistance to fungicides, cellulase and chitinase production, the production of spores at different solid substrates, spores shelf life and the effect to seed germination of Trichoderma spp. isolated from tea soil in İkizdere (Rize) and identified with traditional methods. We identified these isolates mostly as Trichoderma harzianum, one as Trichoderma atroviride and the other Trichoderma hamatum based on ITS sequences. The optimum growth and sporulation temperature of all strains were observed as 28°C and spore viability was determined to be protected up to 65 °C. We found that the ethyl acetate extract of Trichoderma strains have antimicrobial activity, especially ID4A, ID4B ve ID6A strains were found to be effective against M. smegmatis. It was determined that strains were producing essential metabolites, so minimizing the formation sclerotizing and growth of S. sclerotiorum. Strains with the highest enzyme activity and showing strong antifungal activity against plant pathogens (B. cinerea, S. sclerotiorum and R. solani) were determined as T. harzianum ID11C, ID11D, T. atroviride ID20G and T. hamatum ID17E, respectively. It was determined that Trichoderma isolates were resistant to Captan, Dikozin ve Cuprenax fungusists up to 10000 μg/mL level. Also it was found that the efffect of seed germination by T. harzianum ID11C and T. atroviride ID20G strains were higher than the control. In this study, we concluded that T. harzianum ID11D and ID11C isolates were the most suitable strains for biocontrol and plant promoter; and also T. atroviride ID20G and the others could be used for this purpose.