Exploring Trichoderma diversity in the Western Ghats of India: phylogenetic analysis, metabolomics insights and biocontrol efficacy against Maydis Leaf Blight disease

The Western Ghats of India is recognized as one of the world's eight "hottest hotspots" of biological diversity. <i>Trichoderma</i>-a well-known biocontrol agent, was explored from this hotspot. A total of 260 <i>Trichoderma</i> spp. isolates were studied, with 9% exhibiting strong biocontrol potential and crop growth-promoting activity. Furthermore, this study identified three novel isolates-<i>Trichoderma caribbaeum</i> var. <i>caribbaeum</i>, <i>Trichoderma lixii</i>, and <i>Trichoderma brevicompactum</i>-which are reported for the first time from the Western Ghats making a significant contribution to the field. Based on internal transcribed spacer ribosomal RNA (ITS-rRNA) and translation elongation factor 1-<i>α</i> (tef-1α) gene sequence analysis, molecular characterization, identified major isolates as <i>Trichoderma koningiopsis</i>, <i>Trichoderma asperellum</i>, <i>T</i>. <i>caribbaeum</i> var. <i>caribbaeum</i>, <i>T</i>. <i>lixii</i>, <i>T</i>. <i>brevicompactum</i>, <i>Trichoderma atroviride</i>, and <i>Trichoderma erinaceum</i>. Seed biopriming with the effective <i>Trichoderma</i> strain TR11 reduced the maydis leaf blight (MLB) disease index to 32.92% and improved plant growth-promoting attributes in maize. Defensive enzyme activities were increased 2.5-4.2-fold in various treatments with the TR11 isolate, along with enhanced lignification postpathogen inoculation, indicating strengthened plant defense mechanisms. The promising strain <i>T. brevicompactum</i>-TR11 produces secondary metabolites; among them, 5% were found to have a role in biocontrol activity such as octadecanoic acid, palmitic acid-TMS, 5-(4-nitrophenoxymethyl), furane-2-carboxaldehyde, and stearic acid-TMS, phosphoric acid-3TMS, galactopyranose, 5TMS. This study explored <i>Trichoderma</i> diversity in the Western Ghats of India with phylogenetic relationship, metabolomics insights, and biocontrol efficacy against MLB disease.