BIOLOGICAL AND MOLECULAR CHARACTERIZATION OF SOME TRICHODERMA ISOLATES WITH HIGHLY ANTIFUNGAL ACTIVITY

Abstract

Phytopathogen fungi are posing serious problems to the worldwide cultivation systems of economically important plants. Eco-friendly bio-control agents become necessary to help in resolving this problem. In this study, soil and rhizosphere samples were collected from five locations in Egypt. While forty three Trichoderma isolates were successfully isolated. Of these forty three fungi, fourteen isolates showed antifungal activity, six of them were belonged to Trichoderma harzianum. The other eight isolates included T. asperellum, T. viride, T. hamatum and T. lixii. The effect of identified isolates of Trichoderma spp. on radial growth and the percentage of inhibition toward the different fungal pathogens were studied in dual culture on Petri dishes. The molecular identification of the isolated Trichoderma spp. was done using two taxon-selective primers (ITS1 & ITS4) for the internal transcribed spacer (5.8S-ITS) region in the nuclear ribosomal repeat unit. The sequence BLAST analysis of the ITS sequences showed that the isolates were belonging to Trichoderma spp. The phylogenetic relationship was conducted between isolated sequences. Full length of chitinase gene (1.2 Kb) was isolated from two different species and comparatively analyzed between other isolates of high antifungal activity. Select the best medium in terms of growth spore production and biomass yield for the production of Trichoderma spp. Keywords: Trichoderma, biocontrol agents, internal transcribed spacer (ITS), chitinase gene, antifungal activity.