采用温室盆栽试验的方法,研究了接种丛枝菌根(arbuscular mycorrhiza,AM)真菌Glomus versiforme对稀土尾矿上大豆(Glycine max)生长、矿质营养吸收、C∶N∶P生态化学计量比、重金属和稀土元素吸收的影响,旨在为稀土尾矿废弃地的生态重建和植被恢复提供基础依据.结果表明,AM真菌G.versiforme与大豆成功建立了互惠共生关系,具有较高的菌根侵染率,平均为67%.接种G.versiforme显著增加了大豆植株地上部和根部的干重,显著提高了大豆植株中P和K的含量,降低了C∶N∶P计量比,符合生长速率假设.接种G.versiforme显著降低了大豆地上部Fe和Cr的浓度,增加了根部Cd的浓度,未显著影响其它重金属的浓度;同时,显著降低了大豆植株地上部和根部轻稀土元素La、Ce、Pr和Nd的浓度.试验初步证明AM真菌对于大豆适应稀土尾矿复合逆境,以及在稀土尾矿上重建植被具有潜在的作用,应进一步验证自然条件下AM真菌的作用潜力.
A greenhouse pot experiment was conducted to investigate the influence of arbuscular mycorrhizal(AM) fungi Glomus versiforme on the plant growth,nutrient uptake,C∶N∶P stoichiometric,uptake of heavy metals and rare earth elements by soybean(Glycine max) grown in rare earth mine tailings.The aim was to provide a basis for the revegetation of rare earth mine tailings.The results indicated that soybean had a high mycorrhizal colonization and symbiotic associations were successfully established with G.versiforme,with an average rate of approximately 67%.The colonization of G.versiforme significantly promoted the growth of soybean,increased P,K contents,and decreased C∶N∶P ratios,supporting the growth rate hypothesis.Inoculation with G.versiforme significantly decreased shoots and roots La,Ce,Pr and Nd concentrations of soybean compared to the control treatment.However,inoculation with G.versiforme had no significant effect on the heavy metal concentrations,except for significantly decreased shoot Fe and Cr concentrations and increased root Cd concentrations.The experiment demonstrates that AM fungi have a potential role for soybean to adapt the composite adversity of rare earth tailings and play a positive role in revegetation of rare earth mine tailings.Further studies on the role of AM fungi under natural conditions should be conducted.