The fungal profiles of spoiled fruits in Dutse metropolis, Jigawa State, Nigeria

Abstract

This study investigated the prevalence and pathogenicity of fungal species associated with spoiled fruits in Dutse Metropolis, Jigawa State, Nigeria, known for its diverse fruit markets and semi-arid climate. A total of 100 spoiled fruit samples, comprising sweet oranges (Citrus sinensis), bananas (Musa sapientum), guavas (Psidium guajava), watermelons (Citrullus vulgaris), and tomatoes (Solanum lycopersicum), were collected and analyzed. Fungal isolation was performed by culturing on Potato Dextrose Agar (PDA) and incubating at room temperature for 5 to 7 days, followed by observation of the fungal growth. These were identified morphologically and microscopically, and pathogenicity tests were conducted to assess their spoilage potential. Aspergillus niger emerged as the most frequently isolated species, representing 19.5% of total isolates and primarily affecting bananas (30%), sweet oranges (20%), watermelons (15%), and tomatoes (15%). Mucor spp. and Saccharomyces spp. followed, with frequencies of 15.9% and 14.6%, respectively. Mucor spp. was particularly identified in bananas (25%), guavas (10%), watermelons (10%), and tomatoes (20%). Saccharomyces spp. predominantly affected watermelons (35%) and sweet oranges (15%). Fusarium spp. (12.2%) were associated with sweet oranges (5%), bananas (15%), guavas (10%), watermelons (10%), and tomatoes (10%). Penicillium spp. (11.0%) were found affecting bananas (20%) and tomatoes (25%). Aspergillus flavus (11.0%) was identified in sweet oranges (10%) and tomatoes (20%), while Rhizopus stolonifer (8.5%) was found in sweet oranges (15%) and bananas (10%). Moreover, Aspergillus fumigatus (7.3%) was present in sweet oranges (10%) and bananas (20%). Futhermore, pathogenicity tests confirmed that all isolated fungal species were capable of causing similar spoilage symptoms in healthy fruits, indicating their potential role in post-harvest losses. These findings demonstrate the significant role of various fungal species in the spoilage of fruits in the area, with Aspergillus niger emerging as a primary concern for fruit quality and safety. Further studies are recommended to explore potential control measures and the impact of environmental factors on fungal prevalence.