简介：Theculturablebacterialpopulationandphospholipidfattyacid(PLFA)profileofcasingsoilwereinvestigatedatdifferentmushroom(Agaricusbisporus)croppingstages.ThechangeinsoilbacterialPLFAswasalwaysaccompaniedbyachangeinthesoilculturablebacterialpopulationinthefirstflush.ComparativelyhigherculturablebacterialpopulationandbacterialPLFAswerefoundinthecasingsoilattheprimordiaformationstageofthefirstflush.TherewasasignificantincreaseintheratiooffungaltobacterialPLFAsduringmushroomgrowth.MultivariateanalysisofPLFAdatademonstratedthatthemushroomcroppingstagecouldconsiderablyaffectthemicrobialcommunitystructureofthecasingsoil.Thebacterialpopulationincreasedsignificantlyfromcasingsoilapplicationtotheprimordiaformationstageofthefirstflush.Casingsoilapplicationresultedinanincreaseintheratioofgram-negativebacterialPLFAstogram-positivebacterialPLFAs,suggestingthatsomegram-negativebacteriamightplayanimportantroleinmushroomsporophoreinitiation.

简介：Thedynamicsofrhizospheremicrobialcommunitiesisimportantforplanthealthandproductivity,andcanbeinfluencedbysoiltype,plantspeciesorgenotype,andplantgrowthstage.ApotexperimentwascarriedouttoexaminethedynamicsofmicrobialcommunitiesintherhizosphereoftwosoybeangenotypesgrowninablacksoilinNortheastChinawithalonghistoryofsoybeancultivation.Thetwosoybeangenotypes,Beifeng11andHai9731,differinginproductivityweregrowninamixtureofblacksoilandsiliceoussand.Thebacterialcommunitieswerecomparedatthreezonelocationsincludingrhizoplane,rhizosphere,andbulksoilatthethirdnode(V3),earlyflowering(R1),andearlypod(R3)stagesusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE)of16SrDNA.Theresultsofprincipalcomponentanalyses(PCA)showedthatthebacterialcommunitystructurechangedwithgrowthstage.Spatially,thebacterialcommunitiesintherhizoplaneandrhizosphereweresignificantlydifferentfromthoseinthebulksoil.Nevertheless,thebacterialcommunitiesintherhizoplaneweredistinctfromthoseintherhizosphereattheV3stage,whilenoobviousdifferenceswerefoundattheR1andR3stages.Forthetwogenotypes,thebacterialcommunitystructurewassimilarattheV3stage,butdifferedattheR1andR3stages.Inotherwords,somebacterialpopulationsbecamedominantandsomeothersrecessiveatthetwolaterstages,whichcontributedtothevariationofthebacterialcommunitybetweenthetwogenotypes.Theseresultssuggestthatsoybeanplantscanmodifytherhizospherebacterialcommunitiesintheblacksoil,andthereexistedgenotype-specificbacterialpopulationsintherhizosphere,whichmayberelatedtosoybeanproductivity.

简介：Thechangesofmicrobialbiomasscarbon(MBC)andnitrogen(MBN)andmicrobialcommunityinthetopsoiloftheabandonedagriculturallandonthesemi-aridLoessPlateauinChinaduringthenaturalsuccessionwereevaluatedtounderstandtherelationshipbetweenmicrobialcommunityandsoilproperties.MBCandMBNweremeasuredusingfumigationextraction,andmicrobialcommunitywasanalyzedbythemethodoffattyacidmethylester(FAME).ThecontentsoforganicC,totalN,MBC,MBN,totalFAME,fungalFAME,bacterialFAMEandGram-negativebacterialFAMEatthenaturalsuccessionsiteswerehigherthanthoseoftheagriculturalland,butlowerthanthoseofthenaturalvegetationsites.TheMBC,MBNandtotalFAMEwerecloselycorrelatedwithorganicCandtotalN.Furthermore,organicCandtotalNwerefoundtobepositivelycorrelatedwithfungalFAME,bacterialFAME,fungal/bacterialandGram-negativebacterialFAME.Naturalsuccessionwouldbeusefulforimprovingsoilmicrobialpropertiesandmightbeanimportantalternativeforsustainingsoilqualityonthesemi-aridLoessPlateauinChina.

简介：narG基因经常为细菌的减少硝酸盐的社区分析被用作一个分子的标记。在这研究，指向narG基因的教材的一个新集合被设计并且把使中毒反应的坡度胶化电气泳动(PCR-DGGE)试金用于嵌套半的聚合酶链。新教材的潜力在直接从在中央、南部的意大利散布的五个不同试验性的地点从土壤提取的DNA上被验证。教材的特性被切除决定，扩大，并且乐队定序由DGGE解决了。种系发生的分析显示出在从学习的土壤检索的序列和narG序列之间的关联从并且-Proteobacteria。这些教材扩展了存在为在土壤的减少硝酸盐的细菌的社区的尺寸和差异上的生态的学习的分子的工具。

简介：Thecharacteristicsofarbuscularmycorrhizalfungal(AMF)communitystructureinvarioussoildepthsandgrowingseasonsofwatermelon(Citrullusvulgaris)grownincommercialgreenhousesinDaxingofBeijingandWeifangandLaiyangofShandong,Chinawereinvestigatedusingbothmorphologicalidentificationanddenaturinggradientgelelectrophoresis.Thesampledsoilshadbeenusedforcontinuousgreenhouseproductionofwatermelonfor0,5,10,15,or20years.Glomusclaroideumwasthedominantspeciesinthegreenhousesoilsplantedfor5,10,and15yearsinLaiyang,whileGlomusmosseaeandGlomusetunicatumweredominantinthenearbyopenfarmlandsoil.Sorenson'ssimilarityindexofAMFcommunitycompositionrangedfrom0.67to0.84inthesoilsplantedfor5years,andfrom0.29to0.33for20yearsamongthethreelocations.Sporeabundance,speciesrichness,andtheShannonindexwerehighestnearthesoilsurface(0-10cm)anddecreasedwithsoildepth,andhigherinJuneandOctoberthaninAugustandDecember.CanonicalcorrespondenceanalysisshowedthatavailablePandthenumberofyearsthatsoilhadbeenusedforgreenhouseproductionwerethemainfactorscontributingtothevarianceofAMFcommunitycomposition.ItwasconcludedthatthecommunitystructureofAMFwasmainlyinfluencedbysoilavailablePandplantingtimeofwatermelonaswellasbysoildepthandseasonalvariationinthecommercialgreenhouse.

简介：土壤drying-rewetting(DRW)事件影响滋养的转变和微生物引起的社区作文；然而，很少对在DRW事件期间弄干紧张的影响被知道。因此，我们在一个试验性的drying-rewetting事件期间与暴露分析了土壤营养素作文和微生物引起的社区到各种各样的弄干的紧张，用从北中国的一块草地的淤泥沃土，在半干旱的气候暴露土壤到大量潮湿条件的地方，并且草地占超过40%国家陆地区域。我们也进行了一个消毒实验检验土壤微生物的贡献到滋养的脉搏。土壤drying-rewetting减少了由9%-27%的碳(C)矿化作用。monosaccharide和矿物质氮(N)内容与更高弄干紧张增加了(弄干到10%gravimetric水内容)，与最高的弄干紧张随增加是204%和110%(弄干到2%gravimetric水内容)，分别地而易变的磷(P)仅仅增加了(在105%)与最高的弄干紧张。而且，微生物引起的生物资源C和N和溶解器官的N的层次与增加弄干紧张减少了并且分别地，而易变的P的增加不与在微生物引起的生物资源P的减小一致，随溶解器官的C和矿物质N的增加被相关。消毒实验结果显示微生物为C和N脉搏主要负责，而非微生物引起的因素是到易变的P脉搏的主要贡献者。Phospholipid丰满的酸分析显示土壤微生物对drying-rewetting事件高度抵抗并且干旱抵抗的组为滋养的转变可能负责。因此，现在的学习证明在drying-rewetting事件期间弄干的中等土壤能改进N，然而并非P的矿化作用，并且不同机制为C，N，和P脉搏负责，这在drying-rewetting期间观察了事件。

简介：Soilmicrobialbiomassandcommunitystructuresarecommonlyusedasindicatorsforsoilqualityandfertility.Ainvestigationwasperformedtostudytheeffectsoflong-termnaturalrestoration,cropping,andbarefallowmanagementsonthesoilmicrobialbiomassandbacterialcommunitystructuresindepthsof0–10,20–30,and40–50cminablacksoil(Mollisol).Microbialbiomasswasestimatedfromchloroformfumigation-extraction,andbacterialcommunitystructuresweredeterminedbyanalysisof16SrDNAusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE).Experimentalresultsshowedthatmicrobialbiomasssignificantlydeclinedwithsoildepthinthemanagementsofrestorationandcropping,butnotinthebarefallow.DGGEprofilesindicatedthatthebandnumberintop0–10cmsoilswaslessthanthatindepthof20–30or40–50cm.Thesesuggestedthatthemicrobialpopulationwashighbutthebacterialcommunitystructurewassimpleinthetopsoil.ClusterandprinciplecomponentanalysisbasedonDGGEbandingpatternsshowedthatthebacterialcommunitystructurewasa?ectedbysoildepthmoreprimarilythanbymanagements,andthesuccessionofbacterialcommunityasincreaseofsoildepthhasasimilartendencyinthethreemanagements.FourteenpredominatingDGGEbandswereexcisedandsequenced,inwhich6bandswereidentifiedasthetaxaofVerrucomicrobia,2bandsasActinobacteria,2bandsasα-Proteobacteria,andtheother4bandsasδ-Proteobacteria,Acidobacteria,Nitrospira,andunclassifiedbacteria.Inaddition,thesequencesof11DGGEbandswerecloselyrelatedtounculturedbacteria.Thus,thebacterialcommunitystructureinblacksoilwasstable,andthepredominatingbacterialgroupswereuncultured.