简介：ToinvestigatedifferencesinphysiologicalcharacteristicsofgrowthandphysiologicalbasisofhighgrowthvigorinthefirstgenerationofPopulusdeltoideswhicharefromdifferentgrowthvigorclones,herewechosetwogroupsofseedlingswithdifferentgrowthvigor:high（A）andlow（B）.Indexesofphenotypeandphysiologyweresuccessivelymeasuredtostudythegrowth,photosynthesisandnutrientabsorption.Thereweresignificantorverysignificantdifferencesindrymassofroot,stem,leafandthetotalbiomassbetweenAandB.Drymatterofrootshadthesmallestproportionindifferentcomponents,andthelargestproportionwassteminA,whiletheleafhadthelargestproportioninB.ChangesingrowthandphysiologicalcharacteristicsshowedacertainregularityduringJunetoSeptember.AllclonesgrewthemostrapidlyandphysiologicalcharacteristicsvariedthemostsignificantlyinJuly.Correlationanalysisshowedthatseedlingheightandgrounddiameterwerebothsignificantlycorrelatedtoleafarea,nightrespirationrate,NH4-uptakerateandthetotalphotosyntheticrate（R>0.826,P<0.05）,suggestingthattheseedlinggrowthwasmainlyaffectedbytheirowntotalphotosyntheticcapacity,nutrientabsorptionandnightrespirationconsumption.Ingeneral,AwassuperiortoBinallthesefactors,whichconstructphysiologicalbasisofthehighgrowthvigor.