Diverse arbuscular mycorrhizal fungi species associated with indigenous trees in a natural forest

Abstract

In terrestrial ecosystems, arbuscular mycorrhizal fungi (AMF) helps land plants in nutrient uptake and protect them against abiotic and abiotic stresses. It is important to study the AMF-plant relationship to fully realize the beneficial potential to support establishment, growth and maintenance of mycorrhizal plants in different ecosystems. Therefore, the objective of this study was to determine the diversity, abundance and population densities of AMF and quantify root colonization of the indigenous trees in Munessa forest. To this end, composite soil samples and fine roots were collected from seven dominant indigenous trees within 10 m x10 m plots in the forest. AMF spores were extracted for taxonomic identification and root colonization with AMF structures was determined for each trees. A total of 39 AMF species (morphotypes) belonging to 10 genera were recovered. Glomus was the most dominant genus followed by Acaulospora. The highest genus richness was recorded from Croton macrostachyus (9). Mean AMF spore density was significantly different (p < 0.05) among indigenous trees, ranging from 860 spores/100 g of dry soil under Albizia shimperiana to 2830 spores/100 g of dry soil under Pouteria adolfiifriedericii. The highest root hyphal colonization was observed in Millettia ferruginea (71%) and Podocarpus falcatus (64%), respectively. Albizia shimperiana was the least colonized tree (44%). AMF spore density was positively correlated with soil available phosphorus (p < 0.05). Extensive studies are required to select AMF inocula for plant growth promotion and recruitment of tree seedlings for plantation and, restoration of forest vegetation and rehabilitation of degraded and dry lands.