低溫和鹽堿脅迫下桑樹光合作用的適應(yīng)性研究.pdf

1、東北林業(yè)大學(xué)碩士學(xué)位論文低溫和鹽堿脅迫下桑樹光合作用的適應(yīng)性研究姓名：胡彥波申請學(xué)位級別：碩士專業(yè)：遺傳學(xué)指導(dǎo)教師：孫廣玉20070601AbstractInthisstudyresponseandadaptatiomofphotosynthesisinleavesofmulberryplantswerestudied，usinggasexchangeandchlorophyllfluorescencetechnologytoInves

2、tigateacclimationmachanismsunderlowtemperaturesaltandlightconditioningStlX墨SResultsshowedasfoUows：1Apparatusoflightabsorptionandlightenergytransferinleavesofmulberrywasestablishedfirstlyduringgrowthsulge，andthenstomataSl

3、lalCmreandfunctionsandC02assimilationwereimprovedgraduallyPhotochemicalinductionofsunlightleaveswasfastertoapproachsteadystatethanthatofweeklightleaves，andinductioninnonphotochemicalquenchingfNPQ)appearedahighlevelinthef

4、irststageandthenwasdeclinePhotochemicalinductionofweaklightleavestookonabiphasicinductionNPQincreasedrapidlythenmaintainedhighvalueforalongtimeItwasinferredfromthisobservationthatlightactivationenhancedsignificantlylight

5、inductioninweak—lightleavesUnderthehighlightconditionstate—transitionquenching(qT)inleavesgrowninnaturallightconditionmadeup18％oftotalnonphotochemicalquenching(qN)，butqToftheweaklightleavesmountedonlyto7％ofqNItmeantthatq

6、TinsanlightleavesplayedmoreimportantroleinlightenergydistributionbetwacnphotosystemI(PSI)andphotosysternlI(PSII)thanthatofweaklightleavesButhi【ghenergyquench(qE)，whichmadeupover65％ofthetotalqN，Wasthemainmechanismofnonpho

7、tochemicalquenchinginleavesgrowninsunlightandweaklightenvironments2TheactivityofPSI[reactioncenter，efficiencyoflightenergytransferandelectrontransportofPSIIdeclinedwhenPSIIcomplexandouterantennaproteins(LHCII)weredamaged

8、bylowtemperatureMoreoveritwasfoundthatincreaseoffluorescenceradiationinmulberryleavesplayedaveryimportantroleinrelievingexcitationpressureandprotectingphotosyntheticapparatusunderlowtemperatureComparisonamongthreemulberr

9、yvarieties，MongoliamulberrywasmoreresistanttolowtemperaturethanQiuyuandQinglongmulberry3EffectofsaltalkalistressonmulberryphotosynthesishadthetimeeffectandconcentrationeffectPhotosyntheticcapabilityinleavesofQiuyuandMong

10、oliamulberrywasdeclinewithIncreaseinsaltconcentrationandstresstimeUnderthesamesaltirOllconcentrationcondition，effectofsaltalkalistressonmulberryphotosynthesiswasmoresignificantthanthatofneutralsaltstressMoreoverresponseo

11、fphotosynthesistoneutralsaltandsaltalkalistressweredifferencesbet、veenQiuyuandMongolialeavesMongoliamulberryWasmoreresistanttoneutralsaltthanthatofQiuyumulberry4mmechanismofmulberryleavesadaptivetosaltalkalistreSS：(1)Sto

12、matalconductanceinductiontolowC02concentration／highirradianceshowedthatstomatalconductanceinleavestreatedfor8daysWasnearlyequalwithleavesofnOtreatmentItwasindicatedthatthedecreaseinstomatalconductanceWaSanefficientadapta