MOLECULAR CHARACTERIZATION, PHYLOGENETIC ANALYSIS AND ANTAGONISTIC POTENTIAL OF SELECTED BIOGENIC FUNGI AGAINST <i>Fusarium oxysporum</i> f. sp. <i>lycopersici</i> CAUSING TOMATO FUSARIUM WILT

Tomato (Solanum lycopersicum L.) production is severely constrained by Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL), a destructive soil-borne fungal pathogen responsible for substantial yield losses worldwide. The increasing environmental concerns associated with synthetic fungicides have intensified the search for sustainable biological control as alternatives to chemical control. This study investigated the molecular characterization, phylogenetic relationships, and antagonistic potential of selected biogenic fungi against FOL under in vitro conditions. Genomic DNA of antagonistic fungi and pathogenic isolates was extracted using Zymo Research extraction protocols and characterized through sequence analysis. The identified antagonistic fungi included Trichoderma harzianum, Aspergillus versicolor, Ganoderma lucidum, Pleurotus florida, and Pleurotus ostreatus. Sequence alignment and phylogenetic analyses confirmed close evolutionary relationships among related taxa within each fungal genus. Distance matrix analysis revealed high genetic similarity between T. harzianum and T. asperellum (99.83%), A. versicolor and A. austroafricanus (99.69%), while G. lucidum showed strong affinity with G. lingzhi (97.43%). Dual culture assays demonstrated significant (P ≤ 0.05) inhibitory effects of the antagonistic fungi against FOL throughout the experimental period. Among the tested organisms, Trichoderma harzianum exhibited the highest inhibition percentage of 76.89% at day 7, followed closely by Ganoderma lucidum and Pleurotus florida (7.12 and 68.77 respectively). In contrast, Pleurotus ostreatus consistently recorded the lowest antagonistic activity (53.11. The results established that antagonistic efficacy increased progressively with incubation period, indicating enhanced fungal interaction and metabolite production over time. The superior antagonistic performance of T. harzianum and G. lucidum may be attributed to rapid colonization ability, nutrient competition, and production of antifungal metabolites. Phylogenetic analyses further validated the genetic distinctiveness and evolutionary relationships among the studied fungi. The study therefore demonstrated that selected biogenic fungi, particularly T. harzianum and G. lucidum, possess significant potential as eco-friendly biological control agents for sustainable management of Fusarium wilt disease of tomato. These findings provide valuable molecular and biological insights for the development of integrated disease management strategies in tomato production systems.