Morphological Characterization of Trichoderma Isolates Purified from the Rhizosphere Soil, Collected from Copper Mining Areas of Uttarakhand, India

Abstract

A total of 49 Trichoderma strains were isolated and purified from rhizosphere soil samples collected from different copper mining sites of Uttarakhand hills. The Trichoderma was isolated from the soil samples using serial dilution and pour plate technique. The Trichoderma Selective Medium (TSM) was used for the isolation and purification of the Trichoderma isolates. The diversity of Trichoderma isolates was assessed based on various morphological characters such as colony colour, pigmentation, presence or absence of concentric ring type growth, colony morphology and spore size. It was observed that Trichoderma spp. exhibited light to dark green colony, produced different coloured pigments on lower side of culture plates. Among 49 isolates, 21 were dark green, 5 light green, 21 light to dark green and 2 whitish to light green in colour. Thirteen isolates (TCMS-5, 6, 10, 12, 14a, 15, 16, 17, 25, 26, 65, 71 and 77) were exhibited concentric ring formation as growth characteristic. Twenty-two isolates exhibited rough, spongy and raised colony, 16 isolates exhibited smooth and flat colony topography, nine isolates were having smooth and flat colony with dense sporulation at border and two showed spongy and fluffy growth with dense sporulation at center. Eleven isolates produced dark brown pigmentation, four light brown, nine pinkish, 17 whitish creamy and eight yellowish green pigmentation on lower side of the culture plate. Conidiospores were oval to sub-oval, measuring 2.82 x 2.75 µm to 5.18 x 5.02 µm in diameter with a mean of 4.00 x 3.86 µm.