学科分类
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6 个结果
  • 简介:西藏Shannan红鹿自然保护区是西藏的红鹿的地理分发的中心。这份报纸论述烘便的小团组在绿植物的时期期间在2013和2014期间收集了的199红鹿的DNA分析的结果。我们成功地与12microsatelliteloci从87个DNA小团组和坚定的单个鉴定提取了DNA。我们在R软件与Capwire评估了人口和各种各样的人口估计的基因差异。87个成功地提取的小团组来自50个个人。在人口,等位基因的平均数字是7.58吗??

  • 标签: 人口估计 基因差异 DNA 西藏 鹿 等位基因
  • 简介:Exclosureisamethodofrehabilitatingdegradedlandsbyprotectingthemfromtheinterferenceofanimalsandfromhumanencroachment,andisusedtoregeneratenativevegetationasawaytoreducesoilerosion,increaserainwaterinfiltrationandprovidefodderandwoodybiomassindegradedgrazinglands.Therefore,westudiedwoodyplantstructure,diversityandregenerationpotentialsin5-and10-yeargrazingexclosuresincomparisonwithopengrazedsitesinasemi-aridenvironment.Dataonspeciesdiversity,abundance,structure,basalarea,frequency,density,andregenerationstatuswerecollectedfrom270sampleplots.Forty-onewoodyspeciesrepresenting20familieswereidentified,with18,28and38speciesfoundinopengrazedareas,andin5-and10-yeargrazingexclosures,respectively.The10-yeargrazingexclosureshadahigher(P<0.05)speciesrichnessandplantdensitiescomparedtothe5-yeargrazingexclosuresandtheopengrazedareas.ThepopulationstructureandregenerationstatusofwoodyspeciesinbothgrazingexclosuresshowedaninvertedJ-shape,indicatingahealthyregenerationstatus,whereashamperedregenerationwasobservedinopengrazedareas.Theestablishmentofgrazingexclosureshadpositiveeffectsinrestoringwoodyplantdiversityandimprovingvegetationstructureandregenerationpotentialsofdegradedgrazinglands.

  • 标签: BASAL area DIVERSITY Important value index
  • 简介:Ricesheathblight,causedbyRhizoctoniasolani(Kühn),isanotorioussoil-bornediseaseprevalentinmanyrice-growingregions.AlthoughseveralsporadicstudiesofmycovirusesinR.solaniAG-1IAhavebeenreportedforsinglestrainofR.solaniAG-1IA,therehavebeennoreportsdescribingthedistributionanddiversityofmycovirusesinnaturalpopulations.Inthisstudy,43R.solaniAG-1IAstrainscollectedfromdifferentlocationsinChinawereexaminedforthepresenceofdsRNAelementstoconfirmthepresenceofviralinfections.Electrophoretypesshowedthat16ofthe43fungalstrains(37.2%)containeddsRNAsthatcanbecharacterizedasviruses.Furthermore,thespecies-specificreversetranscriptionPCR(RT-PCR)showeddsRNAbandswithsimilarsizesdonotalwayscontainthesamevirusbutexistasmixedmycoviralinfections.Thus,ourfindingsindicatemycovirusesinfectingR.solaniAG-1IAinChinaarediverse,widespreadanduniversal.

  • 标签: MYCOVIRUS RHIZOCTONIA SOLANI reverse transcription polymerase
  • 简介:Background:Theimportanceofstructurallydiverseforestsfortheconservationofbiodiversityandprovisionofawiderangeofecosystemserviceshasbeenwidelyrecognised.However,toolstoquantifystructuraldiversityofforestsinanobjectiveandquantitativewayacrossmanyforesttypesandsitesarestillneeded,forexampletosupportbiodiversitymonitoring.Theexistingapproachestoquantifyforeststructuraldiversityarebasedonsmallgeographicalregionsorsingleforesttypes,typicallyusingonlysmalldatasets.Results:HerewedevelopedanindexofstructuraldiversitybasedonNationalForestInventory(NFI)dataofBadenWurttemberg,Germany,astatewith1.3millionhaofdiverseforesttypesindifferentownerships.Basedonaliteraturereview,11aspectsofstructuraldiversitywereidentifiedaprioriascruciallyimportanttodescribestructuraldiversity.Aninitialcomprehensivelistof52variablesderivedfromNationalForestInventory(NFI)datarelatedtostructuraldiversitywasreducedbyapplyingfiveselectioncriteriatoarriveatonevariableforeachaspectofstructuraldiversity.Thesevariablescomprise1)quadraticmeandiameteratbreastheight(DBH),2)standarddeviationofDBH,3)standarddeviationofstandheight,4)numberofdecayclasses,5)bark-diversityindex,6)treeswithDBH>40cm,7)diversityoffloweringandfructification,8)averagemeandiameterofdowneddeadwood,9)meanDBHofstandingdeadwood,10)treespeciesrichnessand11)treespeciesrichnessintheregenerationlayer.Thesevariableswerecombinedintoasimple,additiveindextoquantifythelevelofstructuraldiversity,whichassumesvaluesbetween0and1.Weappliedthisindexinanexemplarywaytobroadforestcategoriesandownershipstoassessitsfeasibilitytoanalysestructuraldiversityinlarge-scaleforestinventories.Conclusions:Theforeststructureindexpresentedherecanbederivedinasimilarwayfromstandardinventoryvariablesformostotherlarge-scaleforestin

  • 标签: Stand structure STRUCTURAL DIVERSITY STRUCTURAL DIVERSITY