简介：Thispaperaimstoconfirmtheoptimalpruningintensitytopromotepaulowniagrowth.Annualdynamicof8growthindicatorsforpruningofthree-year-oldPaulowniatopromotetnmkextensionweresimulatedunder7treatments.TheresultsshowedthatannualgrowthprocesscouldbemodeledreliablybyRichards'function.Eightgrowthparametersweredevelopedincludingfast-growingpoint(t0),initialpointoffast-growingperiod(tl),finalpointoffast-growingperiod(t2),fast-growingperiod(t),growthperiod(Dg),maximumdayincrement(AGRmax),maximumannualincrement(A).Effectsofpruningtopromotetrunkextensionongrowthparameterswereanalyzed.Paulowniaremaining3-6lowerbranchesafterpruninghadrelativelylongerfast-growingperiod(t),growthperiod(Dg),higheraveragedayincrement(Am),maximumdayincrement(AGRmax)andmaximumannualincrement(A).Therefore,lowerdiametergrowthoforiginaltrunkdidnotdecreasesignificantly,andupperdiametergrowthincreasedtosomeextent,Heightanddiametergrowthofgraftingtrunk,andformratioofgraftingtrunkwererelativelyhigher.Totalstockvolumeincrementwasimprovedsignificantlyundertheconditionthatstockvolumeincrementoforiginaltrunkdidnotdecrease.

简介：Nitratereductaseactivity(NRA)indifferentplantorgansandleavesindifferentpositionsofCamptothecaacuminataseedlingswasdeterminedbyanInvivoassay,thediurnalvariationrhythmofNRAinleavesofdifferentpositionswasobserved,andthecorrelationsbetweenleafNRA,leafareaandlaminamassperunitarea(LMA)werealsoexamined.TheresultsshowedthatNRAintheleafwassignificantlyhighest,comparedwiththatinotherorganssuchasroots,stemsandleaves.Inthisexperiment,the10leaveswereselectedfromtheapextothebaseoftheseedlingsinorder.ThedifferentNRAoccurredobviouslyinleavesofdifferentpositionsofC.acuminataseedlingsfromtheapextothebase,andNRAwashigherinthe4th-6thleaves.ThediurnalchangerhythmofleafNRAshowedaonepeakcurve,andmaximumNRAvalueappearedataboutmidday(at12:30orso).NoobviouscorrelationsbetweenNRAandleafareaorlaminamassperunitareawereobserved.ThisstudyofferedscientificfoundationforthefurtherresearchonnitrogenmetabolismofC.acuminata.