东北红豆杉幼苗光合生理特性的季节动态研究中期报告摘要：东北红豆杉（Taxuscuspidatavar.nana）是我国珍稀濒危树种之一，具有高药用价值和经济价值。为了解东北红豆杉幼苗的光合生理特性及其季节变化规律，本研究在萌发期、生长期和休眠期对东北红豆杉幼苗进行了一系列的生理生化指标的测定和分析。结果显示：东北红豆杉幼苗的光合速率、气孔导度、叶绿素含量、类胡萝卜素含量、可溶性蛋白含量、游离氨基酸含量等指标均随着季节的变化而呈现出一定的变化规律。萌发期和生长期是东北红豆杉幼苗的光合能力最强的时期，而休眠期则是光合能力最弱的时期。此外，本研究还对东北红豆杉幼苗的叶片解剖结构、光合色素荧光参数进行了分析，结果表明，东北红豆杉幼苗的叶片组织结构紧密，表皮细胞较多，叶绿素a/b比值较高，荧光参数最大光化学效率（Fv/Fm）和潜在光化学效率（Fv/Fo）较高，表明其具有较强的抗逆性能。综上，本研究为东北红豆杉幼苗的生长和保护提供了一定的理论基础，为其种植和保护提供了科学依据。关键词：东北红豆杉；幼苗；光合生理；季节动态Abstract:Taxuscuspidatavar.nanaisoneoftherareandendangeredtreespeciesinChina,withhighmedicinalandeconomicvalue.InordertounderstandthephotosyntheticphysiologicalcharacteristicsandseasonalchangesofT.cuspidatavar.nanaseedlings,aseriesofphysiologicalandbiochemicalindexesweremeasuredandanalyzedinsproutingperiod,growthperiodanddormantperiod.Theresultsshowedthatthephotosyntheticrate,stomatalconductivity,chlorophyllcontent,carotenoidcontent,solubleproteincontent,freeaminoacidcontentandotherindexesofT.cuspidatavar.nanaseedlingsshowedcertainchangeswiththeseasons.Thesproutingperiodandgrowthperiodweretheperiodswiththestrongestphotosyntheticability,whilethedormantperiodwastheperiodwiththeweakestphotosyntheticability.Inaddition,theleafanatomicalstructureandphotosyntheticpigmentfluorescenceparametersofT.cuspidatavar.nanaseedlingswereanalyzedinthisstudy.TheresultsshowedthattheleaftissuestructureofT.cuspidatavar.nanaseedlingswascompact,withmoreepidermalcells,higherchlorophylla/bratio,highermaximumphotochemicalefficiency(Fv/Fm)andpotentialphotochemicalefficiency(Fv/Fo),indicatingthatithadstrongstressresistance.Inconclusion,thisstudyprovidesatheoreticalbasisforthegrowthandprotectionofT.cuspidatavar.nanaseedlings,andprovidesascientificbasisforitsplantingandprotection.Keywords:T.cuspidatavar.nana;Seedling;Photosyntheticphysiology;Seasonaldynamics