Genetic Improvement of Some Trichoderma Isolates as Biological Control Agent

Abstract

The main objectives of this study were isolation and characterization of some Trichoderma isolates and selection of the best isolates as biocontrol agent. Also improving of these isolates by protoplast fusion and selection of the best strains produced from protoplast fusion. Accordingly, 25 isolates of Trichoderma were obtained and characterized on morphological and molecular bases. It was found that the predominate species in Menoufia governorate was T. harzianum. These isolates showed high ability in inhibition of growth rate of phytopathogenic fungi. Also, they demonstrated different abilities in producing chitinase enzymes (cell wall degradation enzyme for phytopathogenic fungi). Five isolates were selected for improving by protoplast fusion and six isolates obtained from fusion were selected on the basis of their high abilities in hydrolyzing chitin. Also, these strains were better than their parents in inhibition growth rate of phytopathogenic fungi. In addition, they integrated high production of chitinase enzymes. In green house evaluation on faba bean plants, the obtained result showed that the plants treated with these strains and the pathogen were better in growth parameters than the plants treated by the pathogen only. Also, this treatment showed better growth parameters than the plants treated by parenteral isolates and the phytopathogen.