Abstract:In the present study,a three compartment-cultivation system was designed to investigate the development of common mycorrhizal network as mediated by different plant species and also the time effects.Medicago sativa as test plant was grown in two outer compartments,one as donor compartment receiving AM fungal inoculum and another as receiver compartment indicating development of hyphal network.In the first experiment,plants were harvested at 8,10,12 and 14 weeks after planting to test the time effects;while in the second experiment,the middle compartment was left for mediating plants,M.sativa,Leymus chinensis or Lepidium spetalum,which are known to exhibit different mycorrhizal dependency.The experimental results indicated that:(1)At 8 weeks after planting the external hyphae from donor plants penetrated the nylon meshes separating different compartments and colonized receiver plants.At 10 weeks after planting,mycorrhizal colonization rate of receiver plants reached the same level as that of donor plants.However,the plant biomass and shoot P concentrations were significantly lower for receiver plant,indicating asymmetric competition between different plants bridged by hyphal network.(2)Under experimental conditions,different plants in the middle compartment showed no significant effects on mycorrhizal colonization and biomass of receiver plants,but significantly decreased plant biomass and shoot P concentrations of donor plants.In case of L.spetalum or no plants in the spacer compartment,both shoot and root biomass of receiver plants were significantly lower than those of donor plants;while in case of M.sativa and L.chinensis,there were no significant differences in plant biomass between donor and receiver plants.The study demonstrated that both time and mediating plants are important factors influencing development of hyphal network between plant roots,and the established hyphal network could redistribute resources between plants and stimulate plant interactions.