毛穗旱麥草種子位置效應及其生態(tài)適應意義.pdf

1、新疆農(nóng)業(yè)大學碩士學位論文毛穗旱麥草種子位置效應及其生態(tài)適應意義姓名：王愛波申請學位級別：碩士專業(yè)：植物學指導教師：譚敦炎201006IIPositiondependentEffectofSeedIt’sEcologicalAdaptiveSignificanceinEremopyrumdistansAbstractEremopyrumdistans(Eremopyrumdistans(C.Koch)Nevski.)isanannuale

2、phemeralinPoaceae.ItiswidelydistributedintheJunggarDesertwiththespikeletscanproduce16caryopsis(hereafter“seeds”)butonly1%spikeletsproduce46seeds.Seedsofthisspeciescangerminatebothinautumninspring.Inthispaperthemphologyim

3、bibitionacteristicsdmancygerminationacteristicsseedlinggrowthplantsizeseedoutputfromplantsofseedsinpositions123ofaspikeletwhichwerenumberedfromthebottomup(wereplacedingroups123respectively)werestudiedmanipulativelybothin

4、fieldindosthedifferencesamongacteristicsofthreegroupswereanalyzedtheecologicaladaptivesignificanceofseedpositiondependenteffectsinthisspecieswasdiscussed.Themainresultsareasfollows:(1)InEremopyrumdistansseedsizemassdecre

5、asedsignificantlyasseedpositionincreased.(2)Seedsofthreegroupsweredifferentinimbibitionacteristicswiththerateofwaterabsptionofgroup3wassignificantlyhigherthanthatofgroup12.(3)Freshseedsofthreegroupsweredifferentindepthof

6、nondeepphysiologicaldmancywithgroup1＞group2＞group3Seedsofthreegroupsweredifferentindroughtresistanceduringgerminationstagewithgroup1＞group2＞group3Allseedsofthreegroupsweredeadafter34monthsofburialindicatingthisspeciescou

7、ldnotfmpersistentsoilseedbank.(4)Whenregularlywateredseedsofthreegroupsallcouldgerminatedbothinautumninspringwhilethoseundernaturalsoilmoistureconditionsgerminatedonlyinspringattributedtotheverydryweatherintheexperimenta

8、lfieldduringthestudytimeperiod.Bothcohtscompletedtheirlifecycleinearlysummerplantsfromseedsgerminatedinautumnbehavedaswinterannualswhileplantsfromseedsgerminatedinspringbehavedasearlyspringephemerals.Whetherwaterednotwhe