接种丛枝菌根真菌对蜈蚣草吸收铀的影响

采用盆栽土壤实验,模拟铀(uranium,U)污染土壤,以蜈蚣草(Pteris vittata L.)为研究材料,每盆接种丛枝菌根真菌地表球囊霉(Glomus versiforme,Gv)30 g,探索蜈蚣草菌根对U污染土壤不同时间段的修复效果.结果表明,蜈蚣草菌根侵染率2013年9月最低为57.14%,2014年3月最高为75.20%,呈先上升后下降的年周期变化规律;同一时期蜈蚣草的生物量(干重)Gv组显著高于CK组,根系最为明显;接种Gv组蜈蚣草各器官总U含量均显著高于CK组,且被吸收的U主要固定在根部,Gv组根部总U含量均高于同一时期CK组;接种Gv组基质中总U含量小于CK组,其中接种Gv后蜈蚣草对铁锰氧化态和硫化物态U的吸收效果最好;基质中各形态U随培养时间的延长含量均呈下降趋势.接种Gv组比CK组富集系数大,且均大于1;菌根侵染率与富集系数呈显著正相关关系.以上结果说明接种Gv促进蜈蚣草对U的吸收,因此,蜈蚣草丛枝菌根真菌共生体对治理U污染土壤有良好的应用前景.

Influence of Uranium in Pteris vittata L. Inoculated by Arbuscular Mycorrhizal Fungus

A pot experiment was carried out to explore the annual changes by bioremediation inoculated with 30 g Glomus versiforme in Pteris vittata L. The results showed that mycorrhizal colonization was the lowest in September 2013 (57.14%), and was the highest in March 2014 (75.20%), following the tendency firstly increasing and then decreasing. The dry biomass was markedly high in Gv than that in CK, especially in roots. The total U was significantly higher in Gv than that in CK, and was fixed predominantly into roots. The media in Gv showed less U than that in CK. It was absorbed the most to iron and manganese oxidable U and sulfide U, and each U species declined accompanying the time prolongation. In addition, bioconcentration factors were higher in Gv compared to those of CK, and both treatments were above 1. Positive relationship was found between mycorrhizal colonization and bioconcentration factors. Therefore, U uptake was enhanced inoculated by Gv, and the symbiont in arbuscular mycorrhizal fungus and Pteris vittata L. had a potential to remediate U polluted soil.