This study aims to describe the diversity of arbuscular mycorrhizal fungi (AMF) associated with onion (Allium cepa L.) in northern Cameroon. Three onion fields are selected in each of the three main onion producing regions of northern Cameroon: Adamawa, North and Far North. Soil and root samples are collected from the onion rhizosphere. All samples from one region are mixed to form a composite sample. The onion is used as a trap plant for mycorrhizal fungi. Parameters such as spore density and mycorrhizal species richness are determined according to standard methods. After spore extraction, specie identification is performed based on morphological information provided by the International Vesicular Mycorrhizal Fungi Collection (INVAM). The results indicate that onion is strongly mycorrhized in the Sudano-Sahelian and High Guinean Savannahs climates of northern Cameroon. Morphological and structural characterization allowed the description of eleven AMF species, belonging to seven genera: Funneliformis mosseae, Glomus manihotis, Glomus constrictum, Rhizophagus intraradices, Sclerocystis sp., Acaulospora denticulata, Acaulospora tuberculata, Acaulospora sp., Scutellospora sp1, Scutellospora sp2 and Gigaspora margarita. These results open opportunities for domestication and application of AMF for sustainable onion productivity in northern Cameroon.

Keywords: Allium cepa L., arbuscular mycorrhizal fungi, diversity, northern Cameroon