Morphological and Molecular Characterization of Fungi Associated with Banana Leaf Spot Symptoms in Kenya

Banana production is threatened by numerous biotic and abiotic constraints, with pests and diseases as the major problems affecting it globally.Fungal diseases are very devastating and can cause up to 100% loss.This study aimed to address the lack of data on fungal diseases of bananas in Kenya's major producing zones (Kisii, Meru, and Taita Taveta) by studying the morphological and molecular diversity of fungi associated with banana leaf spot symptoms.Samples were collected from symptomatic banana leaves and sent for laboratory analysis at the International Livestock Research Institute in Nairobi.Fungi associated with banana leaf spot symptoms were isolated on Potato Dextrose Agar and characterized based on morphological features.Molecular analysis was performed by extracting DNA from the fungal isolates and amplifying the Internal Transcribed Spacer region.Sanger sequencing was performed on the extracted DNA templates, and the sequences were compared against the National Centre for Biotechnology Information GenBank database using the Basic Local Search Tool to confirm the species identity of the isolated fungi.Morphological characterization revealed Fusarium spp. as the most prevalent in Taita Taveta and Kisii, while Alternaria spp.dominated in Meru County.Out of 45 isolates tested, 29 yielded polymerase chain reaction products, 20 were selected for sequencing, and 15 yielded high-quality sequences for BLAST analysis.Alternaria alstroemeriae emerged as the most frequently detected fungal species among the sequenced isolates.Phylogenetic analysis confirmed the genetic diversity of the isolates and their taxonomic placement.These findings provide important information on the diversity and distribution of fungi associated with banana leaf spot symptoms in Kenya.However, the pathogenicity of these isolates was not confirmed, and further studies are required to confirm their role in banana leaf spot disease.