Morphological and Molecular Characterization of Trichoderma spp. from Rhizosphere Soil and Their Antagonistic Activity against Fusarium spp.

Trichoderma species are well known for their biocontrol activity which colonize many soil and tuber-borne and foliage plant pathogens. In this study, 12 native isolates of Trichiderma spp were collected from various crop rhizosphere soil samples and characterized them phenotypically based on morphological and cultural features and genotypically based on sequence analysis of internal transcribed spacer (ITS) region-PCR amplification. The results obtained from phenotypic and genotypic observation revealed that isolates were belonged to five different species namely T. asperellum, T. harzianum, T. longibrachiatum, T. koningii and T. koningiopsis. All Trichoderma isolates produced ~600 bp amplicon and phylogenetic analysis revealed that all isolates were grouped with respective species. Further, the antagonistic potential of all the isolates was evaluated against Fusarium spp. following in vitro dual culture method. The results showed that isolates of T. harzianum exhibited maximum growth inhibition activity. The highest rate of inhibition was recorded with T. harzianum isolate TBT6 (87.1%) followed by TBT7 (82.2%), while the least inhibition was observed in T. longibrachiatum isolate TBT10 (59.7%) after 7 days of incubation. The antagonistic T. harzianum isolate TBT6 can be used for development of Trichoderma based bio-formulation and served as bio-control agent against Fusaium spp. under field conditions.