接种丛枝菌根真菌对紫花苜蓿修复石油污染土壤的潜在作用

The potential effect of Medicago sativa inoculated with arbuscular mycorrhizal fungi on remedying petroleum-contaminated soil

为了解接种丛枝菌根真菌(AMF)对紫花苜蓿(Medicago sativa)修复石油污染土壤的潜在作用,采用盆栽试验方法,研究2个石油浓度(1500 mg/kg和15000 mg/kg)污染下,接种摩西球囊霉(Glomus mosseae,G.m)对紫花苜蓿株高、生物量、根系形态、球囊霉素相关土壤蛋白(GRSP)和总石油烃(TPHs)去除率的影响.结果显示:(1)紫花苜蓿生物量随着石油污染浓度的增加而减少,且根系生物量受到的抑制作用最为明显,而接种G.m使根系生物量的减少量降低,根冠比增加;在15000 mg/kg石油浓度下,接种G.m使根长增加17.65%,比根长(SRL)增加29.72%;(2)接种G.m使土壤中TPHs去除率在2个石油污染浓度下分别提高14.09%和24.76%;(3)土壤中易提取GRSP(EE-GRSP)与总GRSP(T-GRSP)比值随石油浓度的增加而降低,在15000 mg/kg石油浓度下,接种G.m使EE-GRSP含量显著降低,而T-GRSP含量显著增加;(4)相关性分析表明,植物根系SRL和菌根侵染率的增加有助于提高TPHs的去除率,同时提高土壤中T-GRSP含量.本研究表明AMF-植物共生体有助于提高植物自身在石油污染土壤中的耐受性,以及根际土壤石油污染物的去除率,说明该技术在石油污染土壤修复工程中具有一定的应用潜力.(图6表3参52)

In order to evaluate the potential function of arbuscular mycorrhizal fungi(AMF)-Medicago sativa symbiosis in remediating petroleum-contaminated soils, we performed a pot-culture experiment to investigate the effects of inoculation with Glomus mosseae(G.m) on plant height, biomass, root morphology, glomalin-related soil protein(GRSP) contents, and removal rate of total petroleum hydrocarbons(TPHs) under the two petroleum contamination concentrations of 1 500 mg/kg and 15 000 mg/kg. The results demonstrated the following:(1) Plant biomass was decreased with increasing concentration of petroleum contamination, and root biomass was the most inhibited part;however, inoculating the soil with G.m decreased the reduction of root biomass and increased the root/shoot ratio. The root length and specific root length(SRL) of G.m-inoculated plants increased by 17.65% and 29.72% in 15 000 mg/kg soil.(2) Inoculation of soil with G.m increased the removal rate of TPHs using concentrations of 1 500 mg/kg and 15 000 mg/kg by 14.09% and 24.76%, respectively.(3) The value of easily extracted GRSP(EE-GRSP)/total GRSP(T-GRSP) decreased with increasing concentrations of TPHs. EE-GRSP was significantly lower, whereas T-GRSP was significantly higher, in 15 000 mg/kg G.m-inoculated soil.(4) SRL and mycorrhizal infection rate was positively related to the removal rate of TPHs. Moreover, T-GRSP was positively correlated with SRL. In conclusion, AMF-plant symbiosis played a positive role in improving the growth of plants and the removal rate of TPHs in petroleum-contaminated soil. Therefore, it is feasible to apply this green remediation technology to petroleum-contaminated soil cleanup projects.