简介：Dustemissionsfromsmelters,asamajorcontributortoheavymetalcontaminationinsoils,couldseverelyinfluencesoilquality.Downwindsurfacesoilswithin1.5kmofazincsmelter,whichwasactivefor10yearsbutceasedin2000,inMaguTown,GuizhouProvince,ChinawereselectedtoexaminePb,Zn,andCdconcentrationsandtheirfractionationalongadistancegradientfromazincsmelter,andtostudythepossiblee?ectsofPb,Zn,andCdaccumulationonsoilmicroorganismsbycomparingwithareferencesoillocatedatadownwinddistanceof10kmfromthezincsmelter.Soilswithin1.5kmofthezincsmelteraccumulatedhighlevelsofheavymetalsZn(508mgkg-1),Pb(95.6mgkg-1),andCd(5.98mgkg-1)withlowratiosofZn/Cd(59.1-115)andPb/Cd(12.4-23.4).Compositepollutionindices(CPIs)ofsurfacesoils(2.52-15.2)were3to13timeshigherthanthereferencesoils.Inmetalaccumulatedsoils,exchangeablepluscarbonate-boundfractionsaccountedformorethan10%ofthetotalZn,Pb,andCd.Thesaturationdegreeofmetals(SDM)insoilswithin1.5kmofthesmelter(averaging1.25)wassixtimeshigherthanthatofthereferencesoils(0.209).Asmallersoilmicrobialbiomasswasfoundmorefrequentlyinmetalaccumulatedsoils(85.1-438μgCg-1)thaninreferencesoils(497μgCg-1),andanegativecorrelation(P<0.01)ofsoilmicrobialbiomasscarbontoorganiccarbonratio(Cmic/Corg)withSDMwasobserved.Microbialconsumptionofcarbonsourceswasmorerapidincontaminatedsoilsthaninreferencesoils,andashiftinthesubstrateutilizationpatternwasapparentandwasnegativelycorrelatedwithSDM(R=-0.773,P<0.01).Consequently,dustdepositedPb,Zn,andCdinsoilsfromzincsmeltingwerereadilymobilized,andweredetrimentaltosoilqualitymainlyinrespectofmicrobialbiomass.

简介：Twopotexperimentswithacompletelyrandomdesignand4replicationswereperformedinagreenhousetoexaminetheresponsedifferenceof17cultivarsofpakchoi(BrassicachinensisL.)growninaCu-spikedandacleansoiltoCu.relativelytolerant.Whenthe17cultivarsofpakchoigrewincleangardensoil,theCuconcentrationsintheabovegroundpartwerepositivelycorrelated(r=0.6693)withtheirrootCuconcentrations.However,whentheygrewintheCu-spikedsoilahighlynegativecorrelationcoefficient(r=-0.5376)wasobtainedintheCuconcentrationbetweentheabovegroundpartandtheroot.ThismeantthattheCutolerantcultivarshadaweakabilitytotransferCufromtheirroottotheirabovegroundpart,andthereforestoredmuchmoreCuintheirrootthantheCusensitivecultivars.

简介：Apotexperimentwascarriedouttostudytheeffectsofthreearbuscularmycorrhizalfungi(AMF),includingGlomusintraradices,GlomusconstrictumandGlomusmosseae,onthegrowth,rootcolonizationandCdaccumulationofmarigold(TageteserectaL.)atCdadditionlevelsof0,5and50mgkg-1insoil.Thephysiologicalcharacteristics,suchaschlorophyllcontent,solublesugarcontent,solubleproteincontentandantioxidantenzymeactivity,ofTageteserectaL.werealsoinvestigated.ThesymbioticrelationshipbetweenthemarigoldplantandarbuscularmycorrhizalfungiwaswellestablishedunderCdstress.ThesymbioticrelationshipwasreffectedbythebetterphysiobiochemicalparametersofthemarigoldplantsinoculatedwiththethreeAMFisolateswherethecolonizationratesintherootswerebetween34.3%and88.8%.Comparedwiththenon-inoculatedmarigoldplants,theshootandrootbiomassoftheinoculatedmarigoldplantsincreasedby15.2%-47.5%and47.8%-130.1%,respectively,andtheCdconcentrationandaccumulationdecreased.ThechlorophyllandsolublesugarcontentsinthemycorrhizalmarigoldplantsincreasedwithCdaddition,indicatingthatAMFinoculationhelpedthemarigoldplantstogrowbyresistingCdstress.TheantioxidantenzymesreacteddifferentlywiththethreeAMFunderCdstress.ForplantsinoculatedwithG.constrictumandG.mosseae,theactivitiesofsuperoxidedismutase(SOD)andcatalase(CAT)increasedwithincreasingCdaddition,butperoxidase(POD)activitydecreasedwithincreasingCdaddition.ForplantsinoculatedwithG.intraradices,threeoftheantioxidantenzymeactivitiesweresignificantlydecreasedathighlevelsofCdaddition.Overall,theactivitiesofthethreeantioxidantenzymesintheplantsinoculatedwithAMFwerehigherthanthoseoftheplantswithoutAMFinoculationunderCdstress.Ourresultssupporttheviewthatantioxidantenzymeshaveagreatinfluenceonthebiomassofplants,andAMFcanimprovethecapabilityofreactiveoxygenspecie

简介：植物给供应任何一个NH+4或不的N消息提供者显示出不同生长回答?3。不同N来源的举起也影响根围pH并且因此土壤磷的简历可获得性，特别地在碱的土壤。在在水栽法并且在土壤文化种的燕麦(AvenanudaL.)的根围的植物生长，P举起，和P可获得性不与唯一的NH+4-N,脚底在供应下面被调查?3-N，或联合。脚底没有?3美联储燕麦植物比唯一的NH+4喂积累了更多的生物资源。当N与两NH+4-N被供应时，最高的生物资源累积被观察并且没有?3-N。植物根的生长与比例增加了没有?3in文化媒介。更好的根生长和更高的根/射击比率一致地被观察在没有?3美联储植物。然而，根活力是最高当N被供应没有时?3+NH+4。NH+4供应减少了根围pH但是没由在土壤种，CaHPO4作为P增加了的植物影响P举起来源。没有P缺乏被观察，并且植物P集中通常在2gkg上面?1。当N不部分或作为完全被供应时，P举起被增加?3-N，同样作为生物资源累积。结果建议那燕麦是一没有?3-preferring植物，并且没有?3-N为植物生长和根吸收能力的维护是必要的。有NH+4-N的N供应没改进P营养，它由于P缺乏的缺席是最可能的。

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