DescriptionWe investigated the mechanisms employed by the plants to balance the mutualism with the cooperative and cheating strains in arbuscular mycorrhizal symbiosis. In addition to that we also determined the cooperating and cheating natures of two different arbuscular mycorrhizal fungal strains (009 & 0165). Theoretically the cheating strains should outcompete the cooperative strains. However in nature both the cooperative and cheating strains are well stabilized. To find out how in nature plants manage to stabilize the symbiosis with both cheating and cooperative arbuscular mycorrhizal fungi we conducted different experiments. Here we analyzed the difference in the amount of carbon transferred by the plant to the fungus in the presence and absence of P in the fungal ERM. The plant transferred more carbon to the fungal partner that can provide more P. We also analyzed the difference in the amount of P transferred to the plant by two different fungi under similar conditions. The cooperative strain transferred more P when there is an increase in the C in the roots whereas there was no difference in the cheating strain. We also analyzed the P pools in the roots colonized by both the strains after treating with different amounts of carbon. With the increase in the carbon for the cooperative strain, there is raise in the amount of orthophosphate pool, short chain polyphosphate pool and DNA/protein pool which suggests that an increased availability of carbon for the fungus results in the increased transport of P from the fungus to the plant. Whereas the cheating strain incorporated most of its P in Long chain and short chain polyphosphates making the P unavailable to the plant.