Morphological and molecular identification of fungi associated with corm rot and blight symptoms on plantain ( Musa paradisiaca) in macro-propagators

Abstract

Plantain is a major staple food crop for millions of people in Cameroon and contributes significantly to food security. A limiting factor to large-scale production of plantains is the difficulty in obtaining healthy planting materials. Macro-propagation technology, which has the potential to produce 50-60 shoots per sucker in 4-5 months, was introduced to bypass this difficulty. The aim of this study was to isolate and identify the fungi growing in plantain propagators in Buea municipality, which could probably be responsible for the corm rot and blight symptoms observed. Fungi were isolated from the corm, root, pseudostem, leaves and from fruiting bodies on Potato dextrose agar. Isolates were characterized using cultural, micro-morphological and molecular techniques. A total of 5 isolates were obtained, most of which were whitish in colour and all had septate hyphae, belonging to the Ascomycota. The molecular weight of the DNA of the isolates ranged between 500-800 bp. Based on sequence similarity, these isolates were identified to belong to five species viz: Alternaria burnsii, Fusarium oxysporum, Chaetomium globosum, Hypocrea lixii and Trichoderma harzianum. Of these five isolates, F. oxysporum was the only one that had been reported to be the causal agent of Fusarium wilt (Panama) disease of plantain. Fusarium and Chaetomium are likely responsible for the diseased symptoms observed. Proper management and control of these fungal species in propagators will permit the production of healthy seedlings, thus enabling large scale production of plantains.