被子植物生殖與生物技術(shù)課件

被子植物生殖與生物技術(shù)ToBeorNottoBe(??????)Overview:ToSeedorNottoSeedTheparasiticplant

RafflesiaarnoldiiProducesenormousflowersthatcanproduceupto4millionseedsFigure38.1KeyConceptsConcept38.1:Pollinationenablesgametestocometogetherwithinaflower(受粉作用使得花中的配子聚在一起)Concept38.2:Afterfertilization,ovulesdevelopintoseedsandovariesintofruitsConcept38.3:Manyfloweringplants

clone(複製)themselvesbyasexualreproductionConcept38.4:PlantbiotechnologyistransformingagricultureConcept38.1:Pollinationenablesgametestocometogetherwithinaflower(受粉作用使得花中的配子聚在一起)Inangiosperms,thedominantsporophyte(孢子體)Producessporesthatdevelopwithinflowersintomalegametophytes(pollengrains)(雄配子體、花粉粒)Producesfemalegametophytes(embryosacs)(雌配子體、胚囊)FlowerStructureFlowersArethereproductiveshootsoftheangiospermsporophyte(被子植物配子體)Arecomposedoffourfloralorgans:Sepals(萼片)Petals(花瓣)Stamens(雄蕊)Carpels(雌蕊)FilamentAnther雄蕊Stamen花瓣P(guān)etalReceptacleSepal萼片Style花柱OvaryCarpel雌蕊Stigma花藥花絲卵房柱頭花托被子植物花的多樣性Manyvariationsinfloralstructure

haveevolvedduringthe140millionyearsofangiospermhistoryBilateralsymmetry(orchid)SepalRadialsymmetry(daffodil)FusedpetalsSemi-inferiorovaryInferiorovarySuperiorovaryLupineinflorescenceSunflowerinflorescenceMaize,amonoeciousspeciesDioeciousSagittarialatifolia(commonarrowhead)SYMMETRYOVARYLOCATIONFLORALDISTRIBUTION

Figure38.3REPRODUCTIVEVARIATIONSGametophyteDevelopmentandPollinationInangiosperms(被子植物)Pollination

(受粉作用)isthetransferofpollenfromananther

(花藥)toastigma

(柱頭)Ifpollinationissuccessful,apollengrain

(花粉粒)producesastructurecalledapollentube

(花粉管),whichgrowsdownintotheovary(卵房)anddischargesspermneartheembryosac(胚囊)Keytolabels有絲分裂MITOSIS減數(shù)分裂MEIOSISOvuleOvuleIntegumentsEmbryosacMega-sporangiumMega-sporocyteIntegumentsMicropyleSurvivingmegasporeAntipodelCells(3)PolarNuclei(2)Egg(1)Synergids(2)Developmentofafemalegametophyte(embryosac)雌配子體(胚囊)的發(fā)育(b)(1)Withintheovule’smegasporangiumisalargediploidcellcalledthemegasporocyte(megasporemothercell).(3)Threemitoticdivisionsofthemegasporeformtheembryosac,amulticellularfemalegametophyte.Theovulenowconsistsoftheembryosacalongwiththesurroundinginteguments(protectivetissue).Femalegametophyte(embryosac)Diploid(2n)Haploid(2n)Figure38.4b100m(2)Themegasporocytedividesbymeiosisandgivesrisetofourhaploidcells,butinmostspeciesonlyoneofthesesurvivesasthemegaspore.Embryosacs---DevelopfrommegasporeswithinovulesMechanismsThatPreventSelf-Fertilization(自我受精)Manyangiosperms(被子植物)Havemechanismsthatmakeitdifficultorimpossibleforaflowertofertilizeitself(自我受精)

Figure38.5Stigma柱頭AntherwithPollen有花粉的花藥Stigma柱頭PinflowerThrumflowerThemostcommonanti-selfingmechanisminfloweringplantsIsknownasself-incompatibility(自我排斥、自我不相容),

theabilityofaplanttorejectitsownpollenResearchersareunravelingthemolecularmechanismsthatareinvolvedinself-incompatibilitySomeplantsRejectpollenthathasanS-genematchinganalleleinthestigmacellsRecognitionofselfpollen(自家花粉)Triggersasignaltransductionpathwayleadingtoablock(阻礙)ingrowthofapollentubeConcept38.2:Afterfertilization,ovulesdevelopintoseedsandovariesintofruitsDoubleFertilization(雙重受精)Afterlandingonareceptivestigma(花柱)Apollengrain

(花粉粒)germinatesandproducesapollentube

(花粉管)thatextendsdownbetweenthecellsofthestyle()towardtheovary()Thepollentube

(花粉管)ThendischargestwospermintotheembryosacIndoublefertilization

(雙重受精)OnespermfertilizestheeggTheotherspermcombineswiththepolarnuclei(極核),givingrisetothefood-storingendosperm(胚乳)EmbryoDevelopmentThefirstmitoticdivisionofthezygoteistransverseSplittingthefertilizedeggintoabasalcellandaterminalcellFigure38.7OvuleTerminalcellEndospermnucleusBasalcellZygoteIntegumentsZygoteProembryoCotyledonsShootapexRootapexSeedcoatBasalcellSuspensorEndospermSuspensorStructureoftheMatureSeedTheembryoanditsfoodsupplyAreenclosedbyahard,protectiveseedcoatInacommongardenbean,aeudicotTheembryoconsistsofthehypocotyl,radicle,andthickcotyledonsFigure38.8a(a)Commongardenbean,aeudicotwiththickcotyledons.Thefleshycotyledonsstorefoodabsorbedfromtheendospermbeforetheseedgerminates.SeedcoatRadicleEpicotylHypocotylCotyledons胚根種皮子葉上胚軸下胚軸Theseedsofothereudicots,suchascastorbeansHavesimilarstructures,butthincotyledonsSeedcoatEndospermCotyledonsEpicotylHypocotylRadicleFigure38.8bSeedcoatEndospermCotyledonsEpicotylHypocotylRadicle(b)Castorbean,aeudicotwiththincotyledons.Thenarrow,membranouscotyledons(showninedgeandflatviews)absorbfoodfromtheendospermwhentheseedgerminates.種皮胚根下胚軸子葉上胚軸胚乳Theembryoofamonocot(單子葉)hasasinglecotyledon,acoleoptile,andacoleorhizaFigure38.8c(c)Maize,amonocot.Likeallmonocots,maizehasonlyonecotyledon.Maizeandothergrasseshavealargecotyledoncalleda

scutellum.Therudimentaryshootissheathedinastructurecalledthecoleoptile,andthecoleorhizacoverstheyoungroot.Scutellum(cotyledon)ColeoptileColeorhizaPericarpfusedwithseedcoatEndospermEpicotylHypocotylRadicle(種皮)(胚根)(下胚軸)(上胚軸)(胚乳)(子葉)(芽鞘)(根鞘)FromOvarytoFruitAfruitDevelopsfromtheovaryProtectstheenclosedseedsAidsinthedispersalofseedsbywindoranimalsFruitsareclassifiedintoseveraltypesDependingontheirdevelopmentaloriginFigure38.9a–c(a)Simplefruit.Asimplefruitdevelopsfromasinglecarpel(orseveralfusedcarpels)ofoneflower(examples:pea,lemon,peanut).(b)Aggregatefruit.Anaggregatefruitdevelopsfrommanyseparatecarpelsofoneflower(examples:raspberry,blackberry,strawberry).(c)Multiplefruit.Amultiplefruitdevelopsfrommanycarpelsofmanyflowers(examples:pineapple,fig).PineapplefruitRaspberryfruitPeafruitStamenCarpel(fruitlet)StigmaOvaryRaspberryflowerEachsegmentdevelopsfromthecarpelofoneflowerPineappleinflorescenceStamenCarpelsFlowerOvaryStigmaStamenOvulePeaflowerSeedSeedGermination(種子萌芽)AsaseedmaturesItdehydrates(脫水)andentersaphasereferredtoasdormancy(休眠)SeedDormancy:AdaptationforToughTimesSeeddormancyIncreasesthechancesthatgerminationwilloccuratatimeandplacemostadvantageoustotheseedlingThebreakingofseeddormancy

Oftenrequiresenvironmentalcues,suchastemperatureorlightingcuesFromSeedtoSeedling(從種子到幼苗)Germinationofseedsdependsonthephysicalprocesscalledimbibition(浸潤)TheuptakeofwaterduetolowwaterpotentialofthedryseedFigure38.10aCotyledonHypocotylRadicle(胚根)Epicotyl(上胚軸)Seedcoat(種皮)CotyledonHypocotylCotyledon(子葉)Hypocotyl(上胚軸)(a)Commongardenbean.Incommongardenbeans,straighteningofahookinthehypocotylpullsthecotyledonsfromthesoil.Theradicle(胚軸)isthefirstorgantoemergefromthegerminatingseedInmanyeudicots,ahookformsinthehypocotyl(下胚軸),andgrowthpushesthehookabovegroundFoliageleaves(初生葉)(上胚軸)(上胚軸)FoliageleavesColeoptileColeoptileRadicle(b)Maize.Inmaizeandothergrasses,theshootgrowsstraightupthroughthetubeofthecoleoptile.Monocots(單子葉植物)UseadifferentmethodforbreakinggroundwhentheygerminateThecoleoptile(芽鞘)PushesupwardthroughthesoilandintotheairFigure38.10bConcept38.3:Manyfloweringplantsclone

(複製)themselvesbyasexualreproductionManyangiospermspeciesreproducebothasexuallyandsexually(無性及有性)SexualreproductionGeneratesthegeneticvariationthatmakesevolutionaryadaptationpossibleAsexualreproductioninplantsIscalledvegetativereproduction

(營養(yǎng)繁殖)MechanismsofAsexualReproduction(無性生殖的機制)Fragmentation(裂片)IstheseparationofaparentplantintopartsthatdevelopintowholeplantsIsoneofthemostcommonmodesofasexualreproduction

Insomespecies,therootsystemofasingleparentgivesrisetomanyadventitiousshootsthatbecomeseparateshootsystemsFigure38.11VegetativePropagation(營養(yǎng)繁殖)andAgricultureHumanshavedevisedvariousmethodsforasexualpropagationofangiospermsClonesfromcuttings(切枝、切條)ManykindsofplantsareasexuallyreproducedfromplantfragmentscalledcuttingsGrafting(架接、接枝)InamodificationofvegetativereproductionfromcuttingsAtwigorbudfromoneplantcanbegraftedontoaplantofacloselyrelatedspeciesoradifferentvarietyofthesamespeciesTest-TubeCloning(試管複製)andRelatedTechniquesPlantbiologistshaveadoptedinvitromethodstocreateandclonenovelplantvarieties.Figure38.12a,b(a)Justafewparenchymacellsfromacarrotgaverisetothiscallus,amassofundifferentiatedcells.(b)Thecallusdifferentiatesintoanentireplant,withleaves,stems,androots.Inaprocesscalledprotoplastfusion(原生質(zhì)體融合)Researchersfuseprotoplasts,plantcellswiththeircellwallsremoved,tocreatehybridplantsFigure38.1350mVacuoleChloroplastConcept38.4:PlantbiotechnologyistransformingagriculturePlantbiotechnologyhastwomeanings:ItreferstoinnovationsintheuseofplantstomakeproductsofusetohumansItreferstotheuseofgeneticallymodifiedorganisms

(GMO,基因改造生物)inagricultureandindustryArtificialSelection(人工選擇;人擇)HumanshaveintervenedInthereproductionandgeneticmakeupofplantsforthousandsofyearsMaize(玉米)

IsaproductofartificialselectionbyhumansIsastaple(xxxxx)inmanydevelopingcountries,butisapoorsourceofproteinInterspecifichybridizationofplants(植物的種間雜交)Iscommoninnatureandhasbeenusedbybreeders,ancientandmodern,tointroducenew