Effect of diazotrophic bacteria isolated from a mycelium of arbuscular mycorrhizal fungi on colonization of maize roots by Glomus fistulosum

The inoculation of mycorrhizal maize plants with three isolates of microaer ophilic diazotrophic bacteria obtained from the mycelium of arbuscular myco rrhizal fungi associated with three grasses (Arrhenatherum elatius - bacter ial isolate ARR, Agropyrum repens - isolate AGR and Poa annua - isolate POA ) caused no increase in nitrogen content in plant biomass, The inoculation with bacterial isolate ARR resulted in the decreased plant growth. Bacteria l isolate AGR decreased the percentage of the root length colonized by arbu scular mycorrhizal fungus Glomus fistulosum. The inoculation with both myco rrhizal fungus and isolate POA increased significantly the concentration of phosphorus in plant shoots compared to uninoculated control.