[Effect of elevated atmospheric O3 on arbuscular mycorrhizaL (AM) and its function]

In order to understand the possibility of AM in protecting crops from O3 pollution, simulated experiment was carried out to investigate effect of increased atmospheric O3 (0.02 microL x L(-1), 0.1 microL x L(-1) and 0.2 microL x L(-1)) on AM and its function. The results indicate that mycorrhizal colonization was slightly affected by elevated atmospheric O3, but spore and hypahe growth were significantly impacted. Spore number at high O3 level increased I times than that at ambient O3; hypahe length of AM at low and high O3 level decreased 48.7% and 85.6% than that at ambient O3, respectively. Root biomass, nodule number, horsebean pod and grain weight (excluding the treatment-- S + M) significantly decreased with elevated atmospheric O3, but they markedly increased after inoculation with AM fungi. Compared with the uninoculated treatment, nodule number increased by 2-5 times and grain weight of horsebean increased by 3-6 times after inoculation with AM fungi. Relative function of AM was slightly impacted by elevated atmospheric O3. Although indigenous microbes competed with inoculated AM fungi, inoculation with AM fungi could decrease the stress of O3 on plant, which was positive significant to alleviate crop loss resulted from O3 pollution.