Multifunctional biocontrol and growth-promoting efficacy of the endophytic fungus Chaetomium globosum agent for tomato pathogen management

Fungal pathogens such as Rhizoctonia solani and Alternaria alternata significantly threaten tomato production, causing severe damage to root and foliage and leading to substantial yield losses. Considering the environmental and health concerns associated with synthetic fungicides, this study explored the potential of Chaetomium globosum, an endophytic fungus isolated from healthy tomato leaves, as a sustainable biocontrol alternative. Its identity was confirmed through integrated morphological and molecular analyses. In vitro, C. globosum demonstrated strong antagonistic activity against both pathogens, primarily through mycoparasitism and suppression of spore germination. It also exhibited plant growth–promoting capabilities, including indole-3-acetic acid production, phosphate solubilization, and siderophore secretion. Greenhouse experiments showed that C. globosum reduced symptom development by up to 64.8% in plants challenged with R. solani and by 53.8% in those exposed to A. alternata. Treated plants displayed improved growth, higher chlorophyll content, enhanced nutrient uptake, and increased activity of defense-related enzymes—such as peroxidase, superoxide dismutase, and chitinase—as well as elevated levels of phenolic compounds. These findings underscore C. globosum as a multifunctional and eco-friendly candidate for integrated disease management in tomato cultivation.