Nematicidal Properties of Endophytic Fungi Isolated from Some Musa Species in Cameroon, for the Management of Radopholus similis and Platylenchus coffeae

Abstract

Aims: To evaluate the effectiveness of endophytic fungi isolated from banana and plantain cultivars, in the control of Radopholus similis and Pratylenchus coffeae in vitro. Place and Duration of Study: African Centre for Research on Bananas and Plantain (CARBAP) Njombé and New Biotechnology Laboratory, Faculty of Science, University of Buea, between June 2017 and May 2018. Methodology: Endophytic fungi were isolated from banana and plantain roots and corms using Potatoes Dextrose agar. The isolates were initially identified based on their cultural and micro-morphological characteristics. They were then screened for nematicidal activity against R. similis and P. coffeae in vitro.  DNA was extracted from each isolate which showed nematicidal activity and the 5.8S gene and flanking internal transcribed spacers (ITS1 and ITS2) of the rDNA were amplified and sequenced in order to confirm their identity. Results: A total of eighteen endophytic fungal isolates were obtained from the plant materials. All isolates demonstrated nematicidal activity on both nematodes with the mortality ranging from 5-100%. Filtrate from three isolates: MB2, GN4 and BT1 were the most effective and were able to kill 100% of R. similis and P. coffeae after 12 hours of incubation. Filtrate from isolate GN4 was still very effective (100%) after 12 hours when diluted to 1/100. Solutions of broken mycelia from most of the isolates killed the nematodes, but the nematicidal activity was lower than that for culture filtrates. Isolates were identified to belong to five genera: Fusarium, Aspergillus, Trichoderma, Ceratobasidium and Mucor. Conclusion: The findings here clearly demonstrated the potential of these fungi as biological control agents against R. similis and P. coffeae. However, more work is required to help identify the active ingredients exuded by these fungi in culture which has been demonstrated to have nematicidal effects.