丛枝菌根真菌和两株细菌对土壤中DEHP降解及绿豆生长的影响

采用绿豆为供试植物,通过温室盆栽试验研究接种丛枝菌根(arbuscular mycorrhiza,AM)真菌与DEHP降解菌对DEHP污染土壤的修复作用以及对植物生长的影响.试验土壤中添加DEHP含量为100mg·kg-1,试验设AM真菌Acaulospora laelis 90034、降解菌Bacillus sp.DW1和Gordonia sp.DH3单独接种以及互相组合的联合接种处理,同时设置不接种的对照处理(CK).苗后60 d收获植株.结果表明,AM真菌能很好的侵染绿豆的根系,菌根侵染提高了绿豆地上部分的干重,而对根系的干重则没有显著的影响;同时菌根侵染也促进了绿豆的P营养.但接种DW1与DH3对菌根侵染率与绿豆生长都没有显著影响.3种菌剂无论是单独或者联合接种都能显著促进土壤中DEHP的降解,3种菌剂同时接种则对DEHP的降解能达到最好的协同作用,同时也减少DEHP在绿豆地上部分的累积,这为DEHP污染农田土壤的植物修复提供了理论依据.     

镧-铅复合污染下AM真菌对玉米生长和镧、铅吸收的影响

采用温室盆栽试验的方法,模拟不同程度的镧-铅复合污染土壤(50、200、800 mg·kg~(-1)),研究接种丛枝菌根(arbuscular mycorrhizal,AM)、真菌Claroideoglomus etunicatum(CE)和Rhizophagus intraradices(RI)对玉米(Zea mays L.)菌根侵染率、生物量、矿质营养元素吸收、C∶N∶P生态化学计量比、稀土镧(La)和重金属铅(Pb)吸收、转运的影响,旨在为稀土-重金属复合污染土壤的治理和修复提供科学依据.结果表明,AM真菌CE和RI均与玉米建立了共生关系,平均菌根侵染率为26.7%~95.8%;随着La-Pb复合污染含量的增加,玉米植株菌根侵染率、地上部和根部生物量以及N、P、K、Ca、Mg这5种矿质营养元素含量显著降低,而玉米植株C∶P和N∶P以及地上部和根部La、Pb含量显著增加.接种2种AM真菌使玉米植株生物量显著提高了17.8%~158.9%,地上部和根部P含量显著提高了24.5%~153.8%,降低了C∶P和N∶P,符合生长速率假设.在3种程度La-Pb复合污染含量土壤上,AM真菌使玉米植株根部Pb含量显著增加了51.3%~67.7%,地上部Pb含量显著降低了16.0%~67.7%,Pb从玉米根部向地上部的转运率降低了31.5%~54.7%;同时,接种AM真菌显著增加了轻度LaPb复合污染土壤上玉米植株的La含量,在中度La-Pb复合污染土壤上却显著减少了玉米地上部的La含量,增加了玉米根部的La含量,抑制了La从根部向地上部的转运,重度La-Pb复合污染土壤上均没有显著影响.试验结果初步证明,AM真菌具有促进稀土-重金属复合污染土壤植物修复的潜力,对于稀土-重金属复合污染土壤生态系统的植被恢复具有潜在应用价值.     

丛枝菌根真菌及猪炭对多氯联苯污染土壤的联合修复作用

选用玉米(Zea mays L.)为供试植物,采用盆栽试验研究了接种丛枝菌根(Arbuscular mycorrhiza,AM)真菌(Funneliformis mosseae)和添加不同粒径猪炭对多氯联苯(Polychlorinated biphenyls,PCBs)污染土壤的联合修复效应及其对土壤微生物的影响.结果表明,接种AM真菌(10%接种量)及添加2.5%猪炭对土壤有效磷含量提高具有显著的协同效应,猪炭还显著提高了土壤有机碳、速效钾含量和pH值(p0.05);猪炭显著促进了菌根真菌侵染率,但对玉米根系生物量具有抑制作用.接种AM真菌的同时添加猪炭提高了细菌16S rDNA丰度,且接种AM真菌同时添加粒径0.25 mm猪炭显著促进了土壤PCBs降解率.AM真菌与猪炭改变了土壤微生物种群的相对丰度,其中,Planctomycetes与土壤三氯联苯降解显著相关(r=0.049,p0.05),而Acidobacteria与五氯联苯降解显著相关(r=0.008,p0.01).AM真菌及猪炭提高了土壤有效养分含量,促进了植物生物量和土壤PCBs降解,对PCBs污染土壤具有较好的修复潜力.     

丛枝菌根真菌对稀土尾矿中大豆生长和稀土元素吸收的影响

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.     

丛枝菌根对翅荚木生长及吸收累积重金属的影响

针对湖南某铅锌矿区土壤重金属污染严重问题,采用温室盆栽的方法,以该矿区污染土壤为基质,先锋植物翅荚木(Zenia insignis Chun)为宿主植物,研究摩西球囊霉(Glomus mosseae,Gm)和根内球囊霉(G.intraradices,Gi)两种丛枝菌根(Arbuscular Mycorrhizal,AM)真菌对翅荚木生长和吸收累积重金属的影响.结果表明,重金属污染条件下,两种AM真菌均能与翅荚木形成良好的共生关系,且AM真菌能够显著促进植物吸收磷,增加植物生物量,同时改变植物重金属吸收及分配.总体来说,AM降低了翅荚木体内Fe、Cu、Zn和Pd浓度,同时增加了Fe、Cu、Zn和Pd累积量.而两种AM真菌对植物体内重金属分配影响并不相同,而且受重金属种类影响,接种Gi降低了植物Fe、Zn和Pb的TF值,而接种Gm对植物Zn和Pb的TF值无影响,两种AM真菌对植物Cu的TF值均无影响,表明Gi具有能够强化翅荚木根系固持Fe、Zn和Pb的能力.本研究表明,AM真菌在翅荚木适应重金属污染中起着重要的积极作用,因而在重金属污染土壤的植物修复中具有极高的潜在应用价值,但在具体应用中需考虑菌种和植物组合及重金属类型等因素.     

丛枝菌根真菌对铜尾矿上植物生长和矿质营养的影响

通过温室盆栽试验研究了白三叶草(Trifolium repens Linn)和黑麦草(Lolium perenne L.)在单独和混合种植情况下单独或混合接种丛枝菌根真菌Glomus mosseae和Glomus versiforme对铜尾矿砂中植物生长和矿质营养的影响.试验结果表明,不同接种处理下均以单独种植白三叶草菌根侵染率较高,平均为25%.在单种和混种情况下,接种处理均显著提高了白三叶草地上部的干物重,但对黑麦草生长影响不明显同时,接种处理显著提高了三叶草植株中的磷含量,同时降低了植株铜含量,但对黑麦草植株体内元素含量影响不明显.两种植物混合种植情况下黑麦草显示了相对竞争优势,而菌根共生体能够提高三叶草的竞争能力.试验初步证明丛枝菌根真菌对于豆科植物适应铜尾矿复合逆境(养分贫瘠和重金属污染),以及在尾矿上重建具有物种多样性的植被具有潜在作用,但有必要进一步筛选耐性菌株,并验证自然条件下菌根真菌的作用潜力.     

丛枝菌根真菌在矿区生态环境修复中应用及其作用效果

针对煤矿区生态环境修复中存在的主要问题,研究丛枝菌根真菌与紫穗槐共生状况,丛枝菌根真菌对紫穗槐根系发育的影响及其对煤炭开采塌陷区退化土壤的改良效应.结果表明,接种菌根5个月后,接种丛枝菌根促进紫穗槐地上部分和根系生长,提高了紫穗槐根系侵染率;接种区紫穗槐根际土壤中球囊霉素、易提取球囊霉素含量显著增加;接种菌根提高了紫穗槐根际土壤有效磷和有机质含量,微生物数量明显提高,取得较好的菌根生态效应.接种菌根有利于对矿区根际土壤的改良,促进了矿区生态系统稳定,对维持矿区生态系统的持续性具有重要意义.     

接种菌根对根际微生物群落和磷营养的影响

以白三叶草和紫花苜蓿为供试植物,采用三室装置对不同接种处理的根际土壤微生物数量以及磷营养状况进行了研究.研究结果表明,接种混合茵根真菌的侵染率显著高于其他两种接种单一菌根真菌的处理.接种菌根对植物生长以及根际土壤微生物群落数量的促进作用均较为明显,三种接种处理植物之间的生物量差异不大,接种AM菌根促进了细茵和放线茵数量的增加,对真菌数量略有促进.接种菌根对根际土壤磷吸收有显著的促进作用,有利于植被的生长,为进一步的生态恢复与生物多样性研究奠定理论基础.     

复合污染下丛枝菌根真菌对苎麻吸收重金属的影响

利用室内盆栽试验研究Cu、Zn、As、Cd、Sb五种重金属复合胁迫下接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AM真菌)对苎麻侵染率、生物量、地上部磷含量、重金属浓度及转运系数、抗氧化酶系统的影响。研究结果表明:在复合重金属胁迫条件下,AM真菌能够与苎麻形成良好共生关系,显著促进苎麻地上部对磷的吸收,增加苎麻生物量,改变苎麻抗氧化酶系统,同时调节苎麻对重金属的吸收与分配。具体来说,AM真菌对苎麻的侵染率为33.7%。与非接种组相比,接种组苎麻地上部Zn和Cd含量分别增加了50.3%和100.0%,地下部Cu和Sb的含量分别增加了30.4%和114.3%,地上部和地下部As的含量分别降低了121.6%和416.4%。与非接种组相比,接种组苎麻中Zn、As和Cd的转运系数分别增加了58.6%、148.1%和49.8%,Sb的转运系数降低了64.1%。接种AM真菌促进苎麻地上部对磷的吸收,磷含量增加了50.4%。接种组苎麻地上部与地下部生物量也较非接种组分别增加了22.2%和24.0%。同时接种AM真菌提高了苎麻体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性,分别提高了17.47%、31.75%、6.75%。     

接种丛枝菌根真菌对露天矿区不同配比沙土与黏土的培肥效应分析

在室内盆栽条件下,研究沙土和黄土配比联合接种AM真菌对根际土壤养分、有机质含量,植物叶片营养元素含量等的影响。结果表明:接种AM真菌后玉米的生物量和叶片营养元素含量均呈现不同程度的提高,沙土与黄土质量比为1∶1和3∶1中接菌处理的提高作用较为显著;接菌后土壤中的速效磷和速效钾含量降低的同时有机质含量增加。将黄土和沙土进行优化配比可以显著提高菌根侵染率和玉米的生物量,提高土壤速效磷和有机质的含量,提升玉米叶片的营养元素含量。相关性分析表明,菌根侵染率与土壤各理化指标之间存在相互的正效应,菌根侵染后对植物营养吸收具有协同作用。     

外生菌根对欧洲赤松苗(Pinussylvestris)Cu、Zn积累和分配的影响

通过测定２种不同施锌和施铜水平下苗木和离体菌丝中铜锌含量研究了接种外生菌根（Ｓｕｉｌｌｕｓｂｏｖｉｎｕｓ）对欧洲赤松（Ｐｉ－ｎｕｓｓｙｌｖｅｓｔｒｉｓ）苗生长和微量元素积累和分配的影响． 结果表明菌丝的侵染增加了苗木生长同时也增加了植物体内重金属的含量．然而菌根植物中的重金属大部分分布在根部在铜处理中菌根植物地下部分的铜含量是无菌根植物的２．６倍在锌处理中锌是无菌根植物的１．３ 倍． 说明菌丝侵染使植物将过量的重金属滞留在根部从而增加了植物对过量重金属的抗性．通过进一步测定培养在过量重金属中的离体菌丝的重金属含量结果显示随着外界重金属浓度的增加菌丝分泌物内重金属含量比菌丝内重金属含量增加快说明滞留在根部的重金属可能并没有进入根系而是以某种形态滞留在菌丝分泌物和菌丝内．     

Tolerance of Chrysantemum maximum to heavy metals: The potential for its use in the revegetation of tailings heaps

To find if ornamental plants are applicable to the remediation of metal-polluted areas, the tolerance of chrysanthemum plants (Chysanthemum maximum) var. Shasta to different metals under hydroponic conditions was studied. Their responses as influenced by the mycorrhizal fungus Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe BEG25 on substrates containing mine residues were also investigated. Our results showed that chrysanthemum is a metal-tolerant plant under hydroponic conditions, plants behaving as Pb-excluders, whereas Cd, Cu and Ni were accumulated in roots. Low accumulation in flowers was observed for Cd and Cu but it was concentration-dependent. Ni and Pb were not translocated to flowers. Shoot biomass was not significantly affected by the different rates of mine residue addition for both mycorrhizal and non-mycorrhizal plants. Mycorrhizal plants accumulated less Pb and Cu in both shoots and roots than non-mycorrhizal plants. Chysanthemum could be a prospective plant for revegetation of tailings and the use of inoculation may decrease plant metal accumulation in polluted soils.     

Influences of excessive Cu on photosynthesis and growth in ectomycorrhizal Pinus sylvestris seedlings

Growth and photosynthesis responses were measured for Scots pine( Pinus sylvestris L. cv. ) inoculated with ectomycorrhizal fungi ( Suillus bovinus ) under 6.5 and 25 mg/L Cu treatments to evaluate ectomycorrhizal seedlings‘ tolerance to heavy metal stress. Results showed that excessive Cu can significantly impair the growth and photosynthesis of pine seedlings, but such impairment is much smaller to the ectomycorrhizal seedlings. Under 25mg/L Cu treatment, the dry weight of ectomycorrhizal seedlings is 25% lower than the control in contrary to 53% of the non-mycorrhizal seedlings, and the fresh weight of ectomycorrhizal roots was significantly higher than those of non-mycorrhizal roots, about 25% and 42% higher at 6.5 and 25 mg/L Cu treatments respectively. Furthermore,ectomycorrhizal fungi induced remarkable difference in the growth rate and pigment content of seedlings under excessive Cu stress. At 2.5 mg/L Cu, the contents of total chlorophyll, chlorophyll-a and chlorophyll-b were 30% higher in ectomycorrhizal plants than those in non-mycorrhizal plants. O2 evolution and electron transport of PSI and PSII were restrained by elevated Cu stress. However, no significant improvement was observed in reducing the physiological restraining in ectomycorrhizal seedlings over the non-mycorrhizal ones.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

重金属复合污染下草本植物两两组合水培的富集特性

为了探明草本植物两两组合培养对其重金属富集特性的影响,寻求修复V、Pb、Cd、Cr复合污染的最佳草本植物组合模式,在V、Pb、Cd、Cr 4种重金属〔ρ分别为14.0、0.8、6.0、4.0 mg/L〕共存的水培条件下,研究蒌蒿(Artemisia selengensis turcz)、三叶草(Trifolium repens)、鱼腥草(Houttuynia cordata)和紫花苜蓿(Medicago sativa) 4种草本植物两两组合培养时的重金属富集特性,以及对植物生物量、重金属富集量和转运系数的影响. 结果表明:4种草本植物两两组合培养会在不同程度上影响植物的重金属富集特性,在重金属富集能力方面,蒌蒿、鱼腥草和紫花苜蓿分别与三叶草组合培养时,其地上部分w(Cr)分别比单独培养时提高约157%、303%、639%;两两组合培养时,紫花苜蓿可促进蒌蒿、鱼腥草和三叶草对Pb的吸收. 在重金属转移能力方面,效果最突出的是“三叶草‖紫花苜蓿”组合模式,其中三叶草对V、Pb、Cd、Cr 4种重金属的转运系数分别是单独培养时的1.19、2.52、22.60和1.67倍;对不同组合模式下植物地上部分重金属提取量的分析结果显示,“三叶草‖紫花苜蓿”组合模式对V、Pb、Cd、Cr 4种重金属的提取量均较高,分别为1 555、1 688、473、482 mg/kg,表明该组合模式能够有效缓解地表径流对附近土壤造成的叠加污染. 因此,水培条件下不同草本植物两两组合培养会改变植物的重金属富集特性,并且与植物种类有关.      

不同磷水平下丛枝菌根真菌对纳米氧化锌生物效应的影响

纳米ZnO颗粒是应用最为广泛金属型纳米颗粒(nanoparticles,NPs)之一,对作物和土壤微生物的影响值得关注.丛枝菌根(arbuscular mycorrhizal,AM)是自然界中普遍存在的植物-真菌共生体,对各种环境胁迫具有一定的抵御能力,但菌根效应受土壤和植物磷含量的影响.分别设置0、20、50、100 mg·kg~(-1)这4个磷水平,在接种或不接种AM真菌Funneliformis mosseae、添加或不添加纳米ZnO(500 mg·kg~(-1))条件下在温室中利用玉米进行土壤盆栽试验.结果表明,纳米ZnO没有显著影响玉米生长,但不利于菌根侵染和磷素吸收,并引起锌在植物体内的积累.纳米ZnO和高磷降低玉米菌根侵染,但AM真菌在所有磷水平下均显著促进植物生长.施磷和接菌均可使土壤p H升高、降低纳米ZnO源锌的生物有效性,从而降低锌向玉米地上部分的转运和积累,体现出一定保护作用.接菌在多数情况下显示出积极的菌根效应,尤其在低磷、添加纳米ZnO条件下更为显著.结果首次表明,AM真菌、磷肥均有助于减轻纳米ZnO引起的土壤污染及其所产生的生态和健康风险.     

Source attributions of heavy metals in rice plant along highway in Eastern China

Air and soil pollution from traffic has been considered as a critical issue to crop production and food safety, however, few efforts have been paid on distinguish the source origin of traffic-related contaminants in rice plant along highway. Therefore, we investigated metals (Pb, Cd, Cr, Zn and Cu) concentrations and stable Pb isotope ratios in rice plants exposed and unexposed to highway traffic pollution in Eastern China in 2008. Significant differences in metals concentrations between the exposed and unexposed plants existed in leaf for Pb, Cd and Zn, in stem only for Zn, and in grain for Pb and Cd. About 46% of Pb and 41% of Cd in the grain were attributed to the foliar uptake from atmosphere, and there were no obvious contribution of atmosphere to the accumulations of Cr, Zn and Cu in grain. Except for Zn, all of the heavy metals in stem were attributed to the root uptake from soil, although significant accumulations of Pb and Cd from atmosphere existed in leaf. This indicated that different processes existed in the subsequent translocation of foliar-absorbed heavy metals between rice organs. The distinct separation of stable Pb isotope ratios among rice grain, leaf, stem, soil and vehicle exhaust further provided evidences on the different pathways of heavy metal accumulation in rice plant. These results suggested that further more attentions should be paid to the atmospheric deposition of heavy metals from traffic emission when plan crop layout for food safety along highway.