AMF和PGPR联合修复菲和芘污染土壤的效应

丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）与根围促生细菌（plant growth-promoting rhizobacteria,PGPR）联合降解有毒有机物、修复污染土壤和促进植物生长的作用倍受关注。本试验旨在探究AMF与PGPR联合降解土壤中菲和芘的效应,以菲和芘1:1混合处理浓度各0、50mg/kg、100mg/kg和150mg/kg下对高羊茅Festuca elata接种AMF根内根孢囊霉Rhizophagus intraradices（Ri）、变形球囊霉Glomus versiforme（Gv）、PGPR荧光假单胞菌Pseudomonas fluorescens Ps2-6、芽孢杆菌Bacillus velezensis Ps3-2、Ri+Ps2-6、Ri+Ps3-2、Gv+Ps2-6、Gv+Ps3-2和不接种对照共36个处理。结果表明,供试AMF增加了PGPR的定殖数量;接种PGPR则显著提高AMF的侵染率。AMF、PGPR或AMF+PGPR处理均显著降低土壤中菲和芘含量,促进植物对土壤中菲和芘的吸收,显著提高高羊茅根系和叶片内的菲和芘含量。在土壤中菲和芘100mg/kg和150mg/kg水平下,Gv与Ps2-6及Ri与Ps2-6能相互促进对土壤中菲和芘的去除效应,其中接种Gv+Ps2-6组合处理的去除率最高,达到95%-98%,土壤中多酚氧化酶、脱氢酶和过氧化氢酶活性显著高于单接种处理和不接种对照,而酸性磷酸酶活性变化则表现为相反趋势。其中以Gv+Ps2-6组合处理的多酚氧化酶活性最高,为0.17mg/g,是不接种对照的1.9倍;脱氢酶和过氧化氢酶活性分别达到1.32µg/(g·h)和1.81mL/g;酸性磷酸酶活性则比不接种对照土壤降低27%-45%;易提取球囊霉素相关土壤蛋白含量和总球囊霉素相关土壤蛋白含量分别是不接种对照的1.6倍和1.5倍。

Effects of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria on remediation of soil polluted with phenanthrene and pyrene

Effects of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on degrading toxic organic compounds, rehabilitating polluted soils, and enhancing plant growth are paid more attention to. The purpose of the present study was to evaluate efficiency of AMF and PGPR on remediation of soil polluted with phenanthrene and pyrene. Totally 36 treatments were designed. The experimental plants Festuca elata were inoculated with or without Rhizophagus intraradices (Ri), Glomus versiforme (Gv), Pseudomonas fluorescens Ps2-6, Bacillus velezensis Ps3-2, Ri+Ps2-6, Ri+Ps3-2, Gv+Ps2-6, Gv+Ps3-2. The soil was added with polycyclic aromatic hydrocarbons (PAHs) (phenanthrene:pyrene=1:1 in weight) at the concentrations of 0, 50mg/kg, 100mg/kg, and 150mg/kg. Untreated controls were set up. The results showed that inoculation with AMF promoted the colonization of PGPR, while PGPR significantly increased the colonization percentage of AMF. AMF, PGPR or AMF+PGPR treatments could reduce the content of phenanthrene and pyrene in soil, promote the absorption of phenanthrene and pyrene and significantly increase the content of phenanthrene and pyrene in roots and leaves of F. elata. Under the level of PAHs 100mg/kg and 150mg/kg, Gv and Ps2-6, and Ri and Ps2-6 stimulated each other in removing PAHs from the soil, and the treatment with Gv+Ps2-6 combination showed the highest removal percentage, 95%-98%. The activities of polyphenol oxidase, dehydrogenase and catalase in Gv+Ps2-6 inoculation soil were significantly higher than those in single inoculation and control soil, while the activity of acid phosphatase showed a decreasing trend. The activity of polyphenol oxidase in the soil treated with Gv+Ps2-6 was the highest, being 0.17mg/g and 1.9 times higher than the control; dehydrogenase activity and catalase activity reached 1.32µg/(g·h) and 1.81mL/g respectively; acid phosphatase was 27%-45% lower than that of the control soil. The content of easily extractable glomalin-related soil protein and total glomalin-related soil protein in the soil inoculated with Gv+Ps2-6 was 1.6 times and 1.5 times higher than that in the control, respectively. It is concluded that joint inoculation of AMF and PGPR could improve the content of glomamycin and the activity of soil enzymes. AMF and PGPR could enhance mutually in remediation of polluted soil under certain conditions, and Gv+Ps2-6 was the best combination with application potential.