Antifungal Susceptibility Pattern of Fungi Associated with Selected Tomato (Solanum lycopersicum L.) Cultivars in Makurdi Metropolis, Benue State, Nigeria

Abstract

Tomato (Solanum lycopersicum L.) is an economically important vegetable crop widely consumed in Nigeria; however, its production and postharvest quality are frequently compromised by fungal contamination. This study investigated the antifungal susceptibility pattern of fungi associated with selected tomato cultivars sold in Makurdi metropolis, Benue State, Nigeria. A total of 200 rotten tomato fruits were randomly collected from five major markets (North Bank, Wurukum, High Level, Wadata, and Modern markets) and analysed using standard mycological techniques. Fungal isolation was performed using serial dilution and plating on Potato Dextrose Agar (PDA), followed by purification and identification based on macroscopic and microscopic characteristics. Four fungal species were identified: Candida albicans, Rhizopus arrhizus, Aspergillus fumigatus, and Fusarium oxysporum. The highest occurrence was recorded for Candida albicans (30.83%), followed by Rhizopus arrhizus (26.66%), Aspergillus fumigatus (21.66%), and Fusarium oxysporum (20.83%). Antifungal susceptibility testing using the agar diffusion method showed that all isolates were highly susceptible to fluconazole, with mean inhibition zones ranging from 24.20 ± 0.10 mm to 27.47 ± 0.55 mm. Moderate susceptibility was observed with ketoconazole, while clotrimazole and griseofulvin showed little or no inhibitory activity. These findings highlight the prevalence of pathogenic fungi in market-sourced tomatoes and emphasize the need for improved postharvest handling practices and continuous monitoring of antifungal resistance to ensure food safety and sustainable tomato production.