Isolation, characterization and pathogenicity of fungal pathogens from indigenous postharvest fruits in Akwa Ibom state, Nigeria

Abstract

The study investigated fungal pathogens associated with spoilage of five indigenous fruits (Persia americana, Citrus sinensis, Carica papaya, Annona muricata and Solanum lycopersicum) in Akwa Ibom State, Nigeria. Diseased fruit samples were purchased from nine markets located in three senatorial districts of the State. The phenotypic and genotypic identifications of the fungal pathogens isolated from spoilt fruit samples were carried out using standard cultural, morphological and molecular methods, respectively. The phylogenetic relationship among the fungal species was also constructed using neighbor-joining phylogenetic tree generated based on modified Rogers' genetic distance matrix. The fourteen fungal genera identified (and classified into twenty-two species) were Talaromyces, Lasiodiplodia, Trichoderma, Penicillium, Pichia, Rhizopus, Aspergillus, Fusarium, Moniliella, Mucor, Geotrichum, Candida, Absidia and Purpureocillium. Pathogenicity tests revealed that the fungal isolates were able to cause rots with a range of severity. The most rapid rots were caused by Rhizopus oligosporous, Pichia kudriavzevii and Aspergillus niger within 24 h, while Aspergillus aculeatus and Moniliella suaveolens were slower in initiating rots with earliest being after 48 h. The identification of fungi related with fruit rots and data coming from pathogenicity test are crucial information in order to plan and to apply control strategies during postharvest storage.

Keywords

• fungal pathogens
• fungal rot
• phylogenetic relationship
• diseased fruits
• molecular identification