1、蘭州大學(xué)碩士學(xué)位論文珠芽蓼抗氧化物質(zhì)沿海拔梯度的變化姓名：張雪麗申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：生態(tài)學(xué)指導(dǎo)教師：孫國(guó)鈞20050601AbstractAlpineenvironmentsarecharacterizedbylowtemperature，highirradiationandshortgrowingseasonsPlantsherearcconfrontedwithdecreasingmeantemperatureandincrea

2、singlightintensitiesasaltitudeincreasingAlpineplantshavedevelopedfunctionstoadapttothealpineenvironmentsPolygonumviviparumisaperennialherbaceousplant，belongingtOPolygonaceaeItdistributesinEurope，AmericaandAsiaInChina，itm

3、ainlydistributesinJilin，InnerMongolia，Xinjiang，Shaanxi，Gansu，Sichuan，TibetandQinghaiItgrowsataltitudesrangingfrom2000mto4000mabovesealevelInorderteavelthemechanismsbywhichPolygonumvivparumadaptstoalpineenvironments，sampl

4、esofPolygonumvivparumwerecollectedatdifferentaltitudes(2790m，3200m，3736m，4064m)，andcertainbiochemicalindicatorssuchasthecontentsofamalondialdehyde(MDA)，ascorbateacid(As&DAsA)and91utathione(GsH，GSSG)aswellastheactivitieso

5、fsuperoxidedismutase(SOD)，weremeasuredandcomparedamongdifferentaltitudelevelsTheresultsareastlollows1ThecontentofMDAdidnotchangedobviouslyinleavesofPo&gonumvivparumbutincreasedsignificantlyinrootsasaltitudeincreasing，ind

6、icatingthatoxidativestresswasnotsignificanti0leavesbutinroots2Asaltitudeincreasing，theratioofAsA／totalAsAdidnotchangemuchinleaves，butincreasedsignificantlyinrootsOntheotherhandtheratioofGSH／(GSHGSSG)increasedmarkedlyinle

7、aves，whileunchangdeinrootsItseemedthatGSHplayedakeyroleinleavesbutASAwasmoreimportantinrootsinprotectingfromoxidativestre；s3Asaltitudeincreasing，theactivityofSODwasincreasedfirstly，thendeclinedThemaximumactivitywasobserv

8、edintheplantscollectedat3200mabovesealevel4ThecontentsofHz02descreasedsignificantlyinbothrootsandleavesasaltitudeincr—easingTheincreaseinthecontentsofAsAandGSHinrootsandleavesrespcctix7elymightbecontributedtothedeclineof