Effects of Arbuscular mycorrhizal fungus on photosynthesis and stress resistance of reclamation plants in coal mining subsidence areas

ObjectiveThe experiment was conducted to investigate the effects of Arbuscular mycorrhizal fungus on growth, photosynthesis and stress resistance of reclamation plants in coal mining subsidence areas, and provide some theo-retical references and suggestions for ecological restoring of mining areas. MethodFour reclamation plant species including Prunus discadenia, P. dictyneura, Xanthoceras sorbifolia and Armeniaca sibirica were planted in Shendong coal mining subsidence area in Inner Mongolia. For each plant, inoculation with A. mycorrhizal fungus and no inoculation control(CK) treatments were set. Effects of A. mycorrhizal fungus on plant height, ground diameter, mycorrhiza colonization rate, root activity, net photosynthesis rate(Pn), stomatal conductance(Gs), intercellular CO2 concentration(Ci),transpiration rate(Tr), relative water content, soluble sugar content, proline content, relative electric conductivity and catalase activity were de-tected, and the relations among them were analyzed. ResultCompared with CK, P. discadenia, P. dictyneura, X. sorbifo-lia and A. sibirica formed typical mycorrhizal structure with A. mycorrhizal fungus after inoculation. The mycorrhizal colo-nization rates were 65.42%-76.22%, significantly higher than the corresponding CK(P<0.05, the same below). Root activity increased by 17.3%(P. discadenia), 23.0%(P. dictyneura), 32.5%(X. sorbifolia) and 28.7%(A. sibirica). In treat-ment groups, Pn, Gs, Tr, Ci, relative water content, soluble sugar content, proline content and catalase activity significant-ly increased, which promoted resistance to drought and high temperature of reclamation plants. Correlation analysis demon-strated that mycorrhiza colonization rate was significantly positively correlated with root activity , Pn, Gs, Tr, relative water content, soluble sugar, proline and catalase activity, whereas it was significantly negatively correlated with relative electric conductivity and Ci. ConclusionA. mycorrhizal fungus inoculation is beneficial for reclamation plants in Shendong coal mining subsidence area. Therefore, A. mycorrhizal fungus can be promoted in coal mining subsidence areas with similar conditions as Shendong coal mining area.