Survey and Characterization of Trichoderma spp. Isolated from the Rhizosphere of Banana (Musa spp.) across Tamil Nadu, India

Abstract

A survey-based experimental study was conducted from July 2023 to May 2024 at the Department of Plant Pathology, Faculty of Agriculture, Annamalai University, Tamil Nadu, and in banana fields across major banana-growing regions of the state to isolate, characterize, and identify Trichoderma spp. from the rhizosphere of multiple banana cultivars for potential application in sustainable crop health management. A total of twenty isolates were recovered from soils representing diverse agroclimatic zones, soil types and banana genotypes with distinct genomic backgrounds. Rhizosphere soil samples collected from healthy plants were subjected to serial dilution techniques for the isolation of Trichoderma, and the isolates were examined for colony characteristics and conidial morphology. Genomic DNA was extracted using the CTAB protocol, and the internal transcribed spacer (ITS) region was amplified with universal primers ITS4 and ITS5, followed by sequence analysis through BLAST searches and phylogenetic reconstruction using MEGA X. Twenty morphologically distinct isolates were obtained and characterized as T. asperellum, T. harzianum, T. hamatum, T. atroviride, and T. koningiopsis. The study revealed that the rhizosphere of banana cultivars in Tamil Nadu harbours diverse Trichoderma spp., which serve as potential agents for biocontrol and growth promotion, thereby supporting their integration into sustainable disease management strategies.