Fungal Endophytes of Moringa (Moringa oleifera L.), Neem (Azadirachta indica) and Lavender (Lavandula angustifolia) and Their Biological Control of Fusarium Wilt of Banana

Abstract

Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), significantly affects the productivity of the banana crop in the field. Currently, there are no effective control measures available, and therefore, there is an urgent need to develop novel strategies to control the spread of the disease. Biological control is a promising strategy for the management and control of the disease. The aim of this study was to identify fungal endophytes associated with Moringa (Moringa oleifera), Neem tree (Azadirachta indica) and Lavender (Lavandula angustifolia) and their antifungal activities against Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). We isolated 69 fungal endophytes from different tissues of M. oleifera, A. indica and L. angustifolia and screened for antifungal activity against Foc TR4. Six fungal endophytes exhibited highest antagonistic activity against Foc TR4 based on dual-culture assays. Based on morphology and ITS gene sequence analysis, the selected six endophytes were identified to be related to Alternaria alternata (MB7 and NR3), Neofusicoccum parvum (LB1), Fusarium oxysporum (LR1), Talaromyces amestolkiae (MB14) and Alternaria tenuissima (NB6). The culture filtrates of the six fungal endophytes (LB1, LR1, MB7, MB14, NB6 and NR3) exhibited more than 50% inhibition of mycelial growth of Foc TR4 in vitro and were producers of β-1,3-glucanase. The six fungal endophytes showed biocontrol efficacy against Fusarium wilt in pot experiments. The findings from this study demonstrate that fungal endophytes LB1, LR1, MB7, MB14, NB6 and NR3 should be explored as biocontrol agents and biofertilizers in banana production.