Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils
1College of Environment and Resources, Inner Mongolia University
A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi ＊Glomus aggregatum＊ (GA) and ＊Funneliformis mosseae＊ (FM) on AM colonization rate, biomass, nutrient uptake, C:N:P stoichiometric and Ce uptake by maize (＊Zea＊ ＊mays＊ L.) grown in Ce-contaminated soils. The soils consisted of three concentrations of Ce (100, 500 and 1000 mg_kg-1. The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7.12% to 74.47%. The increasing concentration of Ce in soils significantly decreased mycorrhizal colonization rate, biomass, and nutrition contents of maize, and significantly increased C:P and N:P ratios and Ce contents in shoots and roots of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C:N:P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soil, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoots and roots in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and serve Ce contaminated soil. The experiment demonstrates that AM fungi can alleviate toxic effect of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements.
keywords:arbuscular mycorrhizal fungi,Ce-contaminated soils,maize,plant growth,Ce uptake