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简介：PoplarisoneofthedominanttreespeciesfortheestablishmentoffastgrowingplantationsinShandongProvince.EighteenpoplarclonesbelongingtoPopulusaigeirossectionwereintroducedfromItaly,Turkeyanddomesticregions.Populusdeltoidescv.'Lux'I-69/55(I-69),whichwaswidelyusedinShandongProvince,China,wastakenascontrolclone(I-69).Followingarandomizedcompleteblockdesign,seedlingtestandcontrolledafforestationtrialswerecarriedoutatJuxianCounty,CaoxianCountyandLaiyangCity.Theresultsshowedthatthepoplarclone(Populus×euramericanacv.'102/74'),namely102/74,performedwellbothintermsofadaptabilityandgrowthrate.Themeanheightof13.9m(H),diameteratbreastheightof18.0cm(DBH)andvolumegrowthof0.1445m3(V)were2.2%,21.6%and52.9%higherthanthoseofI-69(CK),respectively,attheageof5yearsatthreeexperimentalsites.Moreover,theclonecanbepropagatedeasilyandshowedhighresistancetopoplardisease,pestaswellassalinityandhadlongergrowingperiod.Furthermore,woodbasicdensityandfiberlengthofnewpoplarclone(102/74)wereassameasI-69(CK).Itwasconcludedthattheselectedclone(102/74)wasidealfortheestablishmentoffast-growingpoplarplantations,especiallyforthepulpwoodplantationsinShandongProvince.

简介：Twenty-fivenewclonesbelongtoPopulusAigeirosofbothdomesticandforeignoriginhadbeenintroducedandtestedatnurserystageinShandongprovince.Resultsshowedthatheight(H),diameteratstembase(DO)andsurvivalrate(SR)variedsignificantlyandgeneticvariationwereverylargeamongtheclones.CVgandbroad-senseheritability(h^2)ofH,DOandSRof1-year-oldstocknurserywere7.43%,9.25%,18.78%and78.91%,96.31%,95.93%,respectively,showinghighgeneticcontrolonthetestedtraits.11superiorcloneswithcharacteristicsofhighgrowthrateandmediumorhighSRwereprimarilyselectedandgeneticgains(△G)ofH,DOandSRwere16.89%,16.08%and13.08%,respectively.Rootinghabitstestofsomeselectedcloneswerealsoconductedbasedonthecuttingcultureinwatercontainerandannualgrowthincrementmeasured.Thedateoffirstrootemergence,numberofmainroots,numberoflateralroots,lengthofmainrootsandtheemergencedateofgrowthpeakvariedtocertaindegreeamongtheselectedclones.

简介：Boththeoreticalandfieldobservationswereexaminedtostudythecloserelationshipbetweensoildegenerationandtheevolutionofgrasslandvegetation.Ageneraln-speciesmodelofequalcompetitionunderdifferentdegreesofsoildegradationwasappliedtofielddatainordertoprobethedynamicprocessesandmechanismsofvegetationevolutionduetotheeffectsofthesoil'secologicaldeteriorationongrasslandvegetation.Comparisonsweremadebetweenthetheoreticalresultsandthepracticalsurveyswithsatisfactoryresults.

简介：Peltophorumdubiumseedsweresettoimbibewithfourtreatments,soakedwithsolutionCaptan0.2%under10and27℃,PEG6000-1.0MPaunder10and27℃.Foreachtreatmenttherewerefourreplicateswith40seedsincubatedin9-cmPetridisheswithdoublefilterpapermoistenedwithtestingsolution.Theimbibitioncurvesshowedthatthefinalweightincreasewerefrom70%to150%inthetreatmentswhenimbibitionenteredalagphase.Seedsweretestedforeffectsongerminationoffivetreatments:controlgroup(nonprimed),primedwithPEG6000-1.0MPaat10and27℃,primedwithCaptan0.2%at10and27℃.Foreachtreatment,therewerethreesub-treatments:seedsweresoakedindistilledwaterfor12,24and36hbeforetheenergytest.GerminationpercentagesofnonprimedseedsandprimedinPEG27℃soakedindistilledwaterduring12hwerethehighest,reaching100%.ThelowestgerminationpercentageoccurredprimedseedswithPEG600027℃andsoakedindistilledwaterduring36h,whichwasonly52%.GerminationmeantimeofprimedseedsinPEGat10℃,soaked24hwas1.08days,meantimeofprimedseedsinPEGat27℃soaked12hwas2.42days.Acceleratedageingresultsshowedlowornogerminationafterageing72h.Controlgrouphadahighergerminationpercentageandseedsweremoreresistanttodeteriorationthanthoseinprimedgroups,bothinPetridish(27℃)andvermiculate(roomtemperature).

简介：Soiltestforavailabilityofnutrientsandheavymetalsisextensivelyservedasameansfortheevaluationsofsoilfertility,andenvironmentaleffectsandphytotoxicityofpollutantsinsoils,andforthefertilizerrecommendationinagriculturalandenvironmentalsciences.Therefore,greatattentionhasbeenpaidtothemeasurementofelementalavailabilityinsoiltest.

简介：Whitebackedplanthopper(WBPH)-resistanceinajaponica/indicadoubledhaploid(DH)ricepopulationestablishedfromacrossbetweenWBPH-resistantjaponicaChunjiang06andsusceptibleindicaTN1,wascomparativelyevaluatedthroughafieldexperimentbasedontheWBPHimmigrantdensityandstandardizedseedboxscreeningtest(SSST).AllthesusceptibleDHlinesinthefieldexperimentbehavedaccordinglyinSSST.However,35ofresistant66lines(53%)inthefield,werecategorizedtosusceptiblegroupsinSSST.Likewise,therewerenosignificantdifferencesinWBPHimmigrantdensitiesamong70DHlinesthatwerehighlyresistanttosusceptibleinSSST.TheresultsrevealedthatSSSTcouldnotevaluateproperlyWBPHresistanceintheDHlines.FourQTLsforWBPH-resistancephenotypedbytheimmigrantdensityweredetectedonchromosomes2,3,4,and11.Ofthem,theQTLonchromosome4wasthemosteffective(LOD21.8,variance78%).FiveQTLsassociatedwithseedlingmortalityweremappedonchromosomes2,3,4,5and6.InadditiontotheQTL(LOD10.5,variance68%)onchromosome4,therewasanothermajorQTL(LOD12.7,variance71%)locatedonchromosome5,whichwasSSST-specificbutmightbeirrespectiveoftheWBPHresistancetraits.