北大植物生物学课件第11讲 叶

叶的形态与功能MorphologyandFunctionsofLeafzz叶的功能叶的功能functionsfunctionszz光合作用光合作用photosynthesisphotosynthesiszz蒸腾作用蒸腾作用transpirationtranspirationzz其它合成作用其它合成作用zz叶的形态组成叶的形态组成zz叶片叶片bladeorbladeorlaminalaminazz叶柄叶柄petiolepetiolezz托叶托叶stipulestipule完全叶和不完全叶CompleteorIncompleteleafSimpleleavesofThotteaAristolochiaceae马兜铃科Thepinnatelycompoundleafofthepea(Pisumsativum).SessileleavesofaMemberofthemustardfamily.Incorn,thebaseoftheleafformsasheatharoundthestem.￩叶舌托叶Perfoliateleaf穿茎叶Theleafofalfalfa苜蓿（Medicagosp.）Peltateleaf盾状叶单叶与复叶SimpleandCompoundleafzz单叶单叶simpleleafsimpleleafzz复叶复叶compoundleafcompoundleafzz羽状复叶羽状复叶pinnatelypinnatelycompoundleafcompoundleafzz掌状复叶掌状复叶palmatelypalmatelycompoundleafcompoundleafHowtodistinguishsimpleandcompoundleaves？(1)Axillarybud(腋芽的有无）——budscouldbefoundinleafaxilsofbothsimpleandcompoundleaves,butnotintheaxilsofleaflets(2)Terminalbud（顶芽）(3)Leafandleafletsdifferinthewaysarranginginstemandpetiole（叶的排列方式）——leavesextendfromthesteminvariousdirections,whereastheleafletsofagivenleafalllieinthesameplane叶脉和叶序LeafVenationandPhyllotaxiszz叶脉叶脉zz羽状脉羽状脉pinnatevenationpinnatevenationzz掌状脉掌状脉palmatevenationpalmatevenationzz平行脉平行脉parallelvenationparallelvenationzz叶序：叶序：叶在茎上的排列方式叶在茎上的排列方式zz互生互生alternatealternatezz对生对生oppositeoppositezz轮生轮生verticillateverticillateororwhorledwhorledPhyllotaxyPhyllotaxy叶序叶序：：alternatealternate互生互生，，oppositeopposite对生对生，，whorledorverticillatewhorledorverticillate轮生轮生alternateoppositeverticillatefascicleLeafveinsofthepumpkinLiriodendrontulipiferaL.北美鹅掌楸Aclearedleafofacottonwood(Populus)Aleavesofmonocotswithparallelveins双子叶植物叶的结构InternalStructureofDicotLeafzz表皮（上、下）表皮（上、下）upperupperandlowerepidermisandlowerepidermiszz角质层角质层cuticlecuticlezz气孔器气孔器和保卫细胞和保卫细胞stoma&guardcellsstoma&guardcellszz叶肉叶肉mesophyllmesophyllzz栅栏组织栅栏组织palisadepalisadeparenchymaparenchymazz海绵组织海绵组织spongyspongyparenchymaparenchymazz叶脉（维管束）叶脉（维管束）veinveinSyringavulgarisL.异面叶与等面叶BifacialLeafandIsobilateralLeafz异面叶：指叶肉中有栅栏组织和海绵组织的分化，栅栏组：指叶肉中有栅栏组织和海绵组织的分化，栅栏组织一般在上表皮的下方。织一般在上表皮的下方。z等面叶：指叶肉中没有栅栏组织和海绵组织的分化，或虽：指叶肉中没有栅栏组织和海绵组织的分化，或虽有分化但栅栏组织在叶片的上、下表皮内方都有分布。有分化但栅栏组织在叶片的上、下表皮内方都有分布。AtransversesectionthroughaportionofthebladeoflilacleafOuterbundlesheathInnerbundlesheathTransversesectionofwheatleaf,typicalofC3grasses.叶柄的结构InternalStructureofPetioleAtransversesectionthroughamidriboflilacleaf禾本科植物（单子叶植物）叶的结构InternalStructureofPoa(Monocot)Leafzz等面叶等面叶zz保卫细胞呈哑保卫细胞呈哑铃型铃型zz泡状细胞或运泡状细胞或运动细胞动细胞bulliformbulliformcellcellormotorcellormotorcellzz具维管束鞘具维管束鞘（厚壁细胞（厚壁细胞或薄壁细胞组或薄壁细胞组成）。成）。phellemcellSilicacellEpidermalcellGuardcellTransversesectionofanannualbluegrassfoldedandnfoldedleaf.C3和C4植物叶的维管束的结构StructureofVascularBundlesinC3andC4Plantszz黑糊糊黑糊糊C4植物叶肉和维管束鞘细胞中叶绿体的结构甘蔗属植物Saccharumofficinarum叶的结构（C4植物）水生植物叶（挺水叶）的结构LeafStructureinAquaticPlantsPondweed眼子菜(Potamogetonsp.)挺水叶沉水叶夹竹桃植物的复表皮及气孔窝Transversesectionofoleander（夹竹桃）leaf.Showingmultipleepidermis(复表皮）andstomatalcrypts（气孔窝）Scanningelectronmicrographsofastomatalcryptinthelowerepidermisofanoleander（夹竹桃）leaf.a:showingnumeroustrichomesliningthecrypt.b:showingoneofthestomatawhicharerestrictedtothecrypt.裸子植物叶的结构StructureofGymnospermLeafzz表皮表皮epidermisepidermiszz下皮层下皮层hypodermishypodermiszz叶肉叶肉mesophyllmesophyllzz维管组织维管组织vascularvasculartissuetissue叶的衰老与脱落AgeingandAbscissionofLeaf叶的变态叶的变态modifiedleavesmodifiedleavesFlytrapplantAbladderwort狸藻Sundew茅膏菜Sarraceniasp.瓶子草Kalanchoesp.伽蓝菜属景天科Sweetpea香豌豆