Morphological and molecular characterization for identification of isolates of Trichoderma spp. from rhizospheric soils of crops in middle Gujarat

摘要

Trichoderma spp. have gained immense importance as a component of biological control in integrated disease management. Three known isolates and five isolates of Trichoderma spp. collected from rhizospheric soils of tomato, brinjal, sorghum, tobacco and groundnut were characterized morphologically and by molecular tools.The isolates showed significant differences in terms of colony characters, sporulation, branching of conidiophores, phialospores colour and shape. RAPD and ITS analysis showed a comparable output grouping distinctly comprising of known isolate T. viride and isolates of T. viride from brinjal and groundnut in one cluster; known isolate T. harzianum and isolates of T. harzianum from tomato and tobacco in another cluster and known isolate T. virens and T. asperellum from sorghum in single cluster. RAPO analysis of eight isolates showed amplification of 391 bands. Analysis of phylogeny of isolates was done by sequencing the ITS region of ribosomal DNA using specific universal primers ITS1 and ITS 4. Multiple nucleotide alignment of ITS 1, ITS 2 and 5.8s region depicted intra-specific and inter-specific variations in the ITS sequences among the three isolates of T. harzianum (known isolate), T. harzianum from tomato and tobacco which showed 97 and 83 per cent similarity. However, among the T. viride (known isolate) and T. viride isolates from brinjal and groundnut, per cent similarity was 84 and 95; while, known isolate of T. virens and 7". asperellum from sorghum, it was 97 per cent.Thus the study was found useful for identification of Trichoderma spp. from rhizospheric soil of different crops.