Diversity of arbuscular mycorrhizal fungi associated with Brachiaria brizantha pastures in lowlands of Oaxaca, Mexico

Brachiaria brizantha is one of the most cultivated grasses for fodder in tropical Americas; however, our knowledge of the arbuscular mycorrhizal fungi (AMF) diversity related to this species remains limited. We characterized the AMF diversity associated with B. brizantha pastures in Oaxaca (Mexico) lowlands and examined the influence of soil properties on AMF species diversity. We report 23 taxa with dominance of Glomeraceae and Acaulosporaceae species. The soil is sandy loam; the acidity is high and shows low values of electric conductivity, magnesium, inorganic nitrogen and available phosphorus and high levels of soil organic matter. Low electric conductivity levels (0.95 dS/m) and magnesium concentrations (1.34 cmol/kg) appear to be associated with low AMF spore density. Our results suggest that B. brizantha pastures in Oaxaca (Mexico) lowlands can harbor a great AMF species richness, similar to others natural grasslands.