Abstract

Arbuscular Mycorhizal Fungi (AMF) occur naturally in agroecosystems and interact symbiotically with crops, facilitating nutrition. This study aimed at assessing the occurrence, abundance and diversity of AMF communities in the maize cropping system and their relation to soils properties in two agroecological zones in South Kivu, eastern DR Congo. Soil samples were collected from eight sites, with 4 sites in highland at 1400 to 2000 m altitude above sea level (in Katana, Kavumu, Mulamba and Mugogo) and four in the lowland at <1000 m (in Luberizi, Bwegera, Luvungi and Kamaniola). Spores were extracted from the field soils, morphologically identified and counted. AMF spores occurrence, abundances, species richness, and diversity were determined. A total of 38 AMF morphotypes distributed in 11 genera were obtained with the majority being from Gigasporaceae, Acaulosporaceae, and Glomeraceae families. This is the first report on the occurrence of these species in the eastern of DR Congo. Acaulospopra excavata, Acaulospopra bireticulata, Densitscutata erythropa, Funneliformis mosseae and Scutellospora pellucida were ubiquitous in all the agroecologies. Spores densities were higher in the highland with the highest recorded in Mulamba. Soil pH and phosphorus content influenced AMF distribution. The many different ubiquitous species indicate adaptation to a wide range of physicochemical environments and could reduce the cost of AMF inoculants production for the region. Maize agroecosystems are rich in AMF diversity and selection of appropriate fungal species from the Gigasporaceae, Acaulosporaceae and Glomeraceae as biofertilizer could contribute in improving crops production.

Key words: Arbuscular mycorrhizal fungi, diversity, occurence, agroecological zones, maize, South Kivu.