The genus Rhizophagus dominates arbuscular mycorrhizal fungi communities in contrasted cassava field soils in Côte d’Ivoire

Native arbuscular mycorrhizal fungi (AMF) associated to cassava (Manihot esculenta), a globally important food crop have been shown to enhance its growth, nutrition and productivity. In order to better characterize levels of AMF diversity and identify species relevant to cassava productivity, deeper sequencing depth of cassava field soils is needed. In this paper, we hypothesise that community composition could be linked to specific edaphic factors within contrasted soils. The arbuscular mycorrhizal fungi (AMF) communities of Manihot esculenta rhizosphere soils was investigated by Illumina MiSeq technology. We analyzed the possible correlation between soil characteristics and AMF community composition in cassava field soils within three different agro-ecological zones. Principal Coordinate Analysis (PCoA) and Permutational Multivariate Analysis of Variance were used to test the relative contribution of each agro-ecological zone in explaining the variation in AMF community composition within cassava field soils. Pearson correlations were used to identify the soil properties that significantly explained AMF community compositions within the three zones. The results have shown that despite the fact that the three zones exhibited contrasted soils, AMF community in cassava field soils was dominated by Glomeraceae (Rhizophagus, Glomus, Funneliformis and Septoglomus), with Rhizophagus as the most dominant core genus. Soil type determined the distribution of AMF communities in cassava field soils, and this effect was attributed to soil properties related to organic matter, three micronutrients (available phosphorus, Ca2+, Mg2+), V% and clay. It was shown that high available phosphorus contents (50-100ppm) reduce diversity but did not affect the dominance of the genus Rhizophagus.