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RECAPLECTURECONCEPTSTOKNOWAbitaboutmylecturesIf(when)Italktoofast,stopmeandmakemeslowdownIfyoudonotunderstandatanytime,stopmeandmakemerepeatIfyouseesomethinghighlightedinRED,itisimportantinformationIfsomethingisinGREEN,alsoworthpayingattentiontoQuestionsareencouraged,NosuchthingasasillyquestionWhystudyplants?Fortheirownsake!Interrestrialecosystems陸地生態(tài)系統(tǒng)

vegetation植物istheprimaryproduceruponwhichallothertrophiclevels營養(yǎng)級dependPlants(vegetation)arekeycomponents基礎(chǔ)組分oftheclimatesystem,globalbiogeochemicalcycles全球生物地球化學(xué)循環(huán),andthebiosphere生物圈Plantsinecosystemcontext

Carnivore2Carnivore1HerbivoreDetritusposers營養(yǎng)鹽CO2Inorganic無機的nutrients營養(yǎng)鹽PlantsubsystemHerbivoresubsystemposition分解作用subsystemRecyclingAutotrophy自養(yǎng)型Heterotrophy異養(yǎng)Photoautotrophy光能自養(yǎng)(photosynthesis)Chemoautotrophy化能自養(yǎng)Chemoheterotrophy化能異養(yǎng)DefinitionofaplantAlmostallplantsarephotosyntheticautotrophs自養(yǎng)生物,asaresomesinglecelledorganisms有機體AutotrophsgeneratetheirownorganicmatterthroughphotosynthesisSunlightenergyistransformedtoenergystoredintheformofchemicalbonds(a)Mosses,ferns,andfloweringplants(b)Kelp(c)Euglena(d)CyanobacteriaPhotosynthesisPhotosynthesisoccursinchloroplasts葉綠體Photosynthesisoccursprimarily主要地intheleaves,inthechloroplasts葉綠體Achloroplastcontains:stroma基質(zhì),afluid流體grana基粒,stacksofthylakoids類囊體Thethylakoidscontainchlorophyll葉綠素Chlorophyllisthegreenpigment色素thatcaptureslightforphotosynthesisThelocationandstructureofchloroplastsLEAFCROSSSECTION橫截面MESOPHYLL葉肉CELLLEAFChloroplastMesophyll葉肉組織CHLOROPLASTIntermembranespace膜間腔OutermembraneInner

membraneThylakoid

compartmentThylakoid類囊體StromaGranumStroma基質(zhì)Grana基粒TheCalvincycle卡爾文循環(huán)makessugarfromcarbondioxide,usingATPandNADPHmadeinlightreactionsLightChloroplastLightreactionsCalvincycleNADP

ADP+PThelightreactionsconvertsolarenergytochemicalenergyProduceATP&NADPH還原型輔酶ⅡAnOverview綜述OfPhotosynthesisPhotoautotrophs光合自養(yǎng)生物thatarenotplantsPurplesulphurbacteria紫色硫細菌PurplesulphurbacteriagainenergyfromlightreactionsandproducetheircellularmaterialsfromCO2.However,theydonotgenerateoxygenduringphotosynthesisbecausetheydonotusewaterasthereductant還原劑;insteadtheyuseH2S.6CO2+6H20=C6H12O6+6O2(plantphotosynthesis)6CO2+6H2S=C6H12O6+6S(bacterialanaerobic厭氧的photosynthesis)KingdomBacteria細菌界

(orMonera無核原蟲類)KingdomArchaea古生菌

(previouslynotdifferentiated區(qū)別frombacteria)KingdomProtista原生生物(orProtoctista) (containsthealgae藻類)KingdomPlantae植物界

(theplants)KingdomFungi真菌

(previouslyconsideredplants)KingdomAnimaliaDomainBacteriaDomainArchaeaDomainEukarya真菌Kingdoms生物界anddomains領(lǐng)域Systematics–thestudyofthediversityoforganismsbothpastandpresent,andtheevolutionaryrelationshipsamongthemTaxonomy–thedescription,identification,nomenclature命名法；術(shù)語,andclassificationoforganismsSystematicsandtaxonomy分類學(xué)SystematicsandtaxonomyPlantae植物界:AngiospermsFamily科:CannabaceaeOrder目:Rosales植]薔薇目Phylum門（分類）；:MagnoliophytaClass種類:Magnoliopsida

Species:CannabissativaL大麻Genus屬:CannabisAlternationofthegenerationsAllmembersofPlantKingdom,Plantae(andsomealgae)undergoaspecializedtypeoflifecycle-AlternationofGenerationsThegenerationschangePloidy

[遺]倍性Ploidy–ARecapTermsDiploid二倍體:acellcontaining2sets(2n)ofchromosomes(vegetativecell–sporophyte孢子體Haploid單倍體:acellcontaining1(1n)setofchromosomes(pollenorovule-gametophyte配子體)Polyploid多倍體:acellcontainingmorethan2setsofchromosomes.Usuallyvegetatively生長地reproduced.Banana = 3nPotato = 4n(tetraploid)Strawberry = 8nSummary

ahaploid(n)gametophytegeneratesgametes(n)viamitosisgametesfusetoformadiploid(2n)zygotezygotegrowsmitoticallyintothesporophyte(2n)thediploid(2n)sporophytegeneratesspores(n)viameiosisreleasedspores(n)growintomaturegametophytes(n)...andthecyclecontinues,generationaftergeneration.AlternationofthegenerationsSummaryMODELSporophyte孢子體DiploidzygoteSpermEggGametophyte配子體HaploidsporesSporangium孢子囊FERTILIZATIONMEIOSISDIPLOID2nHAPLOID單倍體nMalesexorgans:Stamens雄蕊,composedofanther–organthatproducespollen花粉(malegametophyte)Femalesexorgans:Thecarpel心皮Ovaryistheenlargedbasalportionofcarpelthatcontainstheovules卵細胞(femalegametophyte)Thestigma柱頭isthe

receptiveportion部分of

thecarpelforpollen

grainstoadhere粘著FlowerStructurePLANTGROUPSeedplants(gymnospermsandangiosperms)Reduced(usuallymicroscopic微觀的),dependentonsurroundingsporophyte孢子形成體tissuefornutritionDominantGymnosperm裸子植物Angiosperm被子植物Microscopicfemalegametophytes(n)insideovulateconeMicroscopicfemalegametophytes(n)insidethesepartsofflowersMicroscopicmalegametophytes(n)insidepollenconeMicroscopicmalegametophytes(n)insidethesepartsofflowersSporophyte(2n)DominantSporophyte(2n)Reduced,dependentongametophytefornutritionGametophyte(n)ExampleSporophyteDominant顯性的GametophyteMosses苔蘚andothernonvascular無維管的plantsFerns蕨類植物andotherseedlessvascularplantsReduced,Independent(photosyntheticandfree-living)Gametophyte(n)Sporophyte(2n)Sporophyte(2n)ANGIOSPERMSAngiospermmeans“coveredseed”HaveflowersHavefruitswithseedsLiveeverywhere–dominantplantsintheworld260,000species(88%ofPlantKingdom)AngiospermsarethemostsuccessfulandadvancedplantsonearthANGIOSPERMS

GYMNOSPERMSGymnospermmeans“nakedseed”(FromtheGreek:gymnos=naked;sperm=seed)

Moreadvancedthanferns–donothavespores,theyhaveseeds.Theseedsofthegymnospermslackaprotectiveenclosure(unlikefloweringplantswhichhaveflowersandfruit).Examplesofgymnosperms:Conifers(pinetrees),cycads,

ginkgobilobaGYMNOSPERMS

Sporophytegeneration(2n)isdominantSummary≈12,000speciesandsixclassesSporiclifecyclewithsporophytepredominanceGametophyteisoftenreducedtoprothallium(smallhornwort-likeplant)somePteridophytahavemaleandfemalegametophytesHavetruerootsSporophytealwaysstartsdevelopmentfromembryolocatedongametophyteHavetruexylemandphloem,butdonothavesecondarythickeningPTERIDOPHYTA–FERNS

PTERIDOPHYTA–FERNS

SporophytealwaysstartsdevelopmentfromembryolocatedongametophyteBRYOPHYTESTermforthenon‐vascular,free‐sporingplantsweknowasmosses,liverworts,andhornworts.

Noxylemorphloem(i.e.,non‐vascular)

Noseedsorpollen(free‐sporing:sporesarereleasedfromsporophyteandmustfindmoistspottogrow)CuticleabsenttopoorlydevelopedGametophytelarge(relativetootherplants)itisthegreen,persistent,dominantphaseofthelife‐cycle

Requireexternalwaterforfertilization(i.e.,spermfrommalegametophytemustswimtoeggoffemalegametophyte)Gametophyteshavesimpledichotomousbranchingifatallsporophytessmallerthangametophytes&unbranchedNotrueleavesorroots.GametophyteisthedominantgenerationinthelifecyclesofbryophytesBRYOPHYTA

BryophytesporophytesproduceanddispersehugenumbersofsporesOriginsofAgricultureThe“NearEast”Thefertilecrescent(Iran,Iraq,Turkey,Syria,LebanonandIsrael)10,000–11,000yearsagoDomesticationofwheat,barley,pea,lentilThe“FarEast”China(YellowandYangtzeRiverbasins)andThailand11,000–11,500yearsagoDomesticationofriceandmilletThe“NewWorld”MexicoandPeru5,500–10,000yearsagoMaize(corn),squash,bean,chilliesPlantsweredomesticatedinparallelinseveralregionsWheat,barley,pea,lentil~13,000yearsagoRice,soybean~9000yearsagoRice,bean~8500yearsagoCorn,squash,bean,potato~10,000yearsagoDomesticationandcropevolutionhaveoccurredwhereveragriculturewasorispracticedContinuumofevolutionaryactivityratherthandiscretecentresModerndaybreeding–directedevolutionDomesticationSelectiontoproducedesirabletraits:Selectionofnon-shatteringratherthanshatteringheadsSelectionoflargerormorenumerousseedsorfruitsortubersSelectionofnakedratherthanhulledgrains(clingingbracts)WildShatteringgrain“Brittlerachis”Advantage–maximizesseeddispersalDomesticatedNon-shatteringgrain“Toughrachis”Advantage–facilitatesharvestingThehardcasingsaroundmanygrainswereeliminatedTeosinte,thewildrelativeofmaize,hashardcoveringsovereachgrain.Humansselectedagainsttheseduringmaizedomestication.Decreaseinbranchingandincreaseinseedsizewerealsoselectedfor–CORNIntrogressionofadiseaseresistancegeneElitetomatoPoortomatobutdiseaseresistant(resistancegeneindicated)Wewanttoaddadiseaseresistancetraittoan“elite”tomatoplant.Wecrossthetwoplants.Someoftheirprogenyinheritthediseaseresistancetrait,somedon’t–howcanwetellthedifference?IntrogressionofadiseaseresistancegeneWecanusemarkerstolookattheirDNAandidentifythosewiththeresistancegene.It’sfasterandeasierthaninfectingthemtoseethephenotypeIntrogressionofadiseaseresistancegeneIsthisanelite,disease-resistanttomato?No,halfofitsgenesarefromthepoortomatoIntrogressionofadiseaseresistancegeneWehavetorepeatedlycrossbacktotheelitetomato,usingmarkerstoidentifyplantswiththediseaseresistancegeneIntrogressionofadiseaseresistancegeneAfterseveralgenerations,elite,diseaseresistanttomatoMarkersgreatlyacceleratebreedingprogramsIntrogressionofadiseaseresistancegeneLycopersiconesculentumLycopersiconperuvianumBack-crossseriesTomatoCultivarwithnewtraitIntrogressionofaspecifictraitGrass–basicbiologyMonocotyledonous

BasalmeristemExploitedforseed(grain)and/orleaves(forage)

WhatisaVariety?Wheat,Barley,OatsandMaizearealldifferentplantSpeciesWithindifferentspeciesthereareVarieties(AlsocalledCultivars)VarietiesaredistinctiveformsofthesamespeciesproducedbyPlantBreeders.TheypossessdifferentcharacteristicsBreedingnewvarietieshasetechnologicallyadvancedusingmoleculartechniques

47Grass–basicbiologyMonocotyledonous

BasalmeristemExploitedforseed(grain)and/orleaves(forage)

Grasslands,grazingandforageMeristemAregionofundifferentiatedcells,wherecelldivisionoccursTheplant’sequivalentof“stemcells”inanimalsBasalmeristemsofgrassesarenotremovedbygrazingordestroyedbywildfiresGrasslanddominatewhereherbivorepressureishigh,firesarefrequent,managementfavoursgrasses(e.g.mowing)WhatisaVariety?Wheat,Barley,OatsandMaizearealldifferentplantSpeciesWithindifferentspeciesthereareVarieties(AlsocalledCultivars)VarietiesaredistinctiveformsofthesamespeciesproducedbyPlantBreeders.TheypossessdifferentcharacteristicsBreedingnewvarietieshasetechnologicallyadvancedusingmoleculartechniques

50WheatdomesticationWorldwheatgrainyieldsincreasedsubstantiallyinthe1960sand1970sbecauseoftheso-called‘greenrevolution’Newvarietieswithdwarfshootphenotypeswereintroducedleadingto:increasedgrainyieldattheexpenseofstrawbiomass,moreresistancetodamagebywindandrain.Alsofacilitatedincreasedcropfertilizer(N)inputsThesedwarfedvarietieshadanalteredresponsetoGibberellin.ResponseisconferredbymutantdwarfingallelesatoneoftwoReducedheight-1(RHt-B1andRht-D1)loci.PeterHedden,Rothamstedresearch.Theshorterplants(varyingdegreedwarfing)arereducedheight(Rh1,Rh2,Rh3etc.)mutationgenotypeswhichhavereducedsensitivitytothegrowthpromotiveGAsproducedbytheplant.Rht

mutantalleleshadlodging-resistantcharacteristic,theyalsocausedlatefloweringandpartialmale-sterilityintheoriginalNorin10linetheywerefoundin.OrvilleVogelintroducedmodifiergenesfromlocalelitelinesintoNorin10sothatthenewvarietiesrestoredfertilityandfloweringtime.These

Rht

mutantalleleswereexactlywhatwasneededtoproducehigh-yielding,semidwarfwheat.Presently,almostallthecommercialwheatemploysoneofthe

Rht

mutantallelesRhgenesencodemutantformsofDELLAproteins–implicatedinbioticstressMaize–ZeamaysAncestryunclearNoknownancestorsNowentirelydependentonhumans:CannotdisperseitsseedsUnsheathinghusksWarm,moistclimateVeryrapidgrowthHighnutrientdemandTassel(staminateinflorescence)KernelswithhuskEar(pistillateinflorescence)FeedsmorepeopleworldwidethananyothercropStapleacrosslargepartsofSandEAsiaO.sativaindica–longgrain,non-sticky–tropicsO.sativajaponica–shortgrain,sticky(moreamyloseinstarch)–sub-tropicsandtemperate(drier)regionsBrownrice(de-hulledwholegrain)Whiterice(milledandpolishedtoremovebranandgerm;lessnutritious)Rice–OryzasativaOats–AvenasativaGrowinmostsoiltypesandcantolerateacidsoilsWinterandSpringtypes.WinteroatsnotashardyaswinterwheatorbarleyHardyandrelativelynutritiousgrains(usuallyeatenunrefined)Markets–feed–millingforoatcakes,porridgeLivestockfeedCrossbetweenwheatandRyeCombiningsome,butnotallofmoredesirabletraitsofeachFodderandcovercropWithstandswaterloggingandacidsoilsTriticaleCantoleratecoldwintersanddrysummers.Lowerglutencontentthanwheatflour(heavierbread)MarketsRyebreadandcrispbreadRye-SecalecerealeBarley–HordeumvulgareOneoftheoldestcultivatedgrassesNeedslessfertileconditionsthanwheatDomesticationledtoashiftfrom2-rowto6-rowbarleyMarketsforBarleyAnimalfeedMaltingBrewingforbeerDistillingforalcoholicbeveragesOtherhumanconsumption:PearlbarleyBarleycoffee(caféd’orzoinItaly)Barleytea(mugichainJapan)BarleybreadBarleywaterBere(berebarley)A6-rowbarleycultivatedmainlyon5-15hectaresinOrkneyProbablyBritain’soldestcerealincontinuouscommercialcultivationProbablybroughttoScotlandbytheVikingsA‘landrace’adaptedtolowpHsoils,shortgrowingseasonwithlongdaylighthours–the“90daybarley”ImagesfromLandraces

Reproductiveisolationanddifferingconditionsofsoil,nutrients,diseases,wateretccreatednumerouslandracesofourcrops

MaizefromdifferentfieldsLandracesdonothaveafixedcomplementofgenes(alleles)becausefarmersarealwaystradingseedsandconditionschangeovertime

Landracesofonespecieshavethesamegenes,butmanydifferentalleles=biodiversityGlobaldistributionofbiomes

PRAIRIE,GREATPLAINS,STEPPE,VELDT,PAMPAS,PUSZTAAuthorMaximilianD?rrbeckerProductsfromgrazinglivestockMeat/offal/m