Arbuscular Mycorrhizal Fungi in the Rhizosphere of Selected Fruit Tree Species in Maiduguri, Nigeria

Background and Objective: Arbuscular Mycorrhizal Fungi (AMF) enhance plant growth, nutrient uptake, and stress tolerance, yet information on the native AMF associated with fruit trees in Maiduguri is limited. This study aimed to investigate the occurrence, diversity, and colonization potential of AMF in the rhizosphere and roots of selected fruit trees to identify dominant species suitable for inoculum production. Materials and Methods: Root and rhizosphere soil samples were collected from Citrus sinensis (Orange), Anacardium occidentale (Cashew), Carica papaya (Pawpaw), Musa sp. (Banana), and Mangifera indica (Mango) in an established orchard at the University of Maiduguri. The AMF spore density, root colonization, and soil physico-chemical properties were determined using standard methods. The AMF morphotypes were identified to genus level, and Pearson correlation was used to assess relationships between soil properties and AMF parameters. Results: The AMF were present in all sampled trees, with root colonization ranging from 49.13% to 69.01%. Fifteen AMF morphotypes representing five genera Glomus, Acaulospora, Funneliformis, Claroideoglomus, and Gigaspora were identified. Glomus was most dominant (40%), followed by Acaulospora (29%), Funneliformis (13%), Claroideoglomus (12%), and Gigaspora (6%). Species richness varied among tree species; pawpaw hosted four of the five genera, while Gigaspora was absent. Soil organic carbon and pH positively influenced AMF spore density and root colonization, whereas bulk density and available phosphorus showed negative correlations. Conclusion: The study identifies dominant native AMF genera in the rhizosphere of fruit trees in Maiduguri, highlighting their potential as inoculum for sustainable fruit production. Soil management targeting pH and organic carbon may enhance AMF symbiosis. Further studies could evaluate the efficacy of these AMF species under field inoculation trials.