丛枝菌根真菌与高羊茅协同修复镉污染土壤

本研究采用温室盆栽试验,利用丛枝菌根（AM）真菌摩西管柄囊霉Funneliformis mosseae进行接种试验,研究了在Cd胁迫下（0、5、15和30mg/kg）接种AM真菌对高羊茅Festuca elata ‘Crossfire II’的生物量、防御酶活性、磷和镉（Cd）含量的影响。结果表明,随着Cd浓度的增加,高羊茅的菌根侵染率和菌根相对依赖性有所增加。接种AM真菌改善了磷从植株根系向地上部的转运,有助于植株在地上部积累更多的磷。此外,AM真菌和Cd胁迫对高羊茅植株抗氧化酶活性都有显著影响,在镉胁迫下,与未接种植株相比,接种AM真菌显著提高了植株的过氧化氢酶活性,而显著降低了植株的丙二醛含量。与未接种植株相比,接种摩西管柄囊霉显著提高了寄主植物对Cd的富集能力,有利于重金属在根部的积累,同时降低了地上部的Cd含量。本研究表明,高羊茅-丛枝菌根共生体在Cd污染土壤的修复中具有潜在应用价值。

Synergistic utilization of arbuscular mycorrhizal fungi and Festuca elata for remediating cadmium-contaminated soils

A greenhouse pot experiment was conducted using tall fescue(Festuca elata'CrossfireⅡ')inoculated with or without the arbuscular mycorrhizal(AM)fungus Funneliformis mosseae.Plant biomass,defense enzyme activities,phosphorus(P)uptake,and available cadmium(Cd)content were determined in tall fescue plants grown in soil with Cd added at 0,5,15,and 30mg/kg.As the Cd concentration increased,the mycorrhizal colonization and mycorrhizal relative dependency of the tall fescue increased.The presence of AM fungi improved P transportation from roots to the shoots,which helped the plant accumulate more P in the shoots.In addition,the activities of antioxidant enzymes were largely induced by the AM fungi and Cd stress in the tall fescue plants.In particular,the catalase activity in AM fungus-inoculated plants increased significantly compared to the non-inoculated control.Malondialdehyde content decreased significantly in inoculated plants compared with control plants under Cd stress.Inoculating F.mosseae greatly enhanced the Cd enrichment capacity of the host plants and was conducive to fixing heavy metals within roots and reducing Cd content in the shoots compared to the non-inoculated control.This study shows that tall fescue inoculated with AM fungi has good potential as a Cd phytoremediator.