Exploring Banana Phyllosphere Fungi for Biocontrol of Fusarium in Daloa, Côte d’Ivoire

Abstract

Banana, contributing to food security and the economy in Côte d’Ivoire, is subjected to multiple biotic and abiotic stresses. The intensive use of chemical inputs promotes resistance in pathogenic fungi while contributing to environmental pollution. The phyllospheric microbiome of banana, whose structure varies according to geographical conditions, represents a potentially exploitable resource for the development of biological control strategies. This study aimed to evaluate the antagonistic potential of phyllospheric fungi associated with banana. Fifty‑four leaf samples (27 apparently healthy and 27 symptomatic) were collected from nine plantations distributed across three localities: Zokoguhé, Bribouo and Gonaté. The analytical approach consisted of isolating fungi present in the leaf samples and assessing their antifungal activities through solid‑medium confrontation assays between antagonists and pathogens. The fungi isolated from banana leaves belonged to the genera Trichoderma, Aspergillus, Fusarium, Cladosporium, Mucor, Exophiala, Rhizomucor, Citalidium, Pestalotiopsis, Aureobasidium, Scytalidium and Alternaria. Among them, Trichoderma reesei, with a highest prevalence of 83.33%, appears to be a core member of the fungal community associated with banana leaves. It showed the strongest antagonistic activity, inhibiting Fusarium oxysporum growth by 54.56%. These findings demonstrate that the banana phyllosphere harbors fungal communities of interest, capable of exerting biocontrol activity.