被子植物生殖與生物技術(shù)ppt課件

1、Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsPowerPoint Lectures for Biology, Seventh EditionNeil Campbell and Jane ReeceLectures by Chris Romero(5) Chapter 38Angiosperm Reproduction and Biotechnology被子植物生殖與生物技術(shù)被子植物生殖與生物技術(shù)Copyright 2005 Pearson Education, Inc. publishing as

2、Benjamin CummingsTo Be or Not to Be (?) Overview: To Seed or Not to Seed The parasitic plant Rafflesia arnoldii Produces enormous flowers that can produce up to 4 million seedsFigure 38.1Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsKey ConceptsConcept 38.1: Pollination enabl

3、es gametes to come together within a flower (受粉作用使得花受粉作用使得花中的配子聚在一同中的配子聚在一同)Concept 38.2: After fertilization, ovules develop into seeds and ovaries into fruitsConcept 38.3: Many flowering plants clone (複製複製) themselves by asexual reproductionConcept 38.4: Plant biotechnology is transforming agricul

4、tureCopyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 38.1: Pollination enables gametes to come together within a flower (受粉作用使受粉作用使得花中的配子聚在一同得花中的配子聚在一同) In angiosperms, the dominant sporophyte (孢子體孢子體) Produces spores that develop within flowers into male gametophytes (

5、pollen grains) (雄配子體、花粉粒雄配子體、花粉粒) Produces female gametophytes (embryo sacs) (雌配子體、胚囊雌配子體、胚囊)Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsFlower Structure Flowers Are the reproductive shoots of the angiosperm sporophyte (被子植物配子體被子植物配子體) Are composed of four floral organs: Se

6、pals (萼片萼片) Petals (花瓣花瓣) Stamens (雄蕊雄蕊) Carpels (雌蕊雌蕊)FilamentAnther雄蕊雄蕊Stamen花瓣花瓣P(guān)etalReceptacleSepal萼片萼片Style花柱花柱OvaryCarpel雌蕊雌蕊Stigma花藥花藥花絲花絲卵房卵房柱頭柱頭花托花托Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings被子植物花的多樣性被子植物花的多樣性 Many variations in floral structure have evolved durin

7、g the 140 million years of angiosperm historyBilateral symmetry(orchid)SepalRadial symmetry(daffodil)Fused petalsSemi-inferior ovaryInferior ovarySuperior ovaryLupine inflorescenceSunflower inflorescenceMaize, a monoecious speciesDioecious Sagittaria latifolia (commonarrowhead) SYMMETRY OVARY LOCATI

8、ON FLORAL DISTRIBUTION Figure 38.3 REPRODUCTIVE VARIATIONS Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsGametophyte Development and Pollination In angiosperms (被子植物被子植物) Pollination (受粉作用受粉作用) is the transfer of pollen from an anther (花藥花藥) to a stigma (柱頭柱頭) If pollination

9、is successful, a pollen grain (花粉花粉粒粒) produces a structure called a pollen tube (花粉管花粉管), which grows down into the ovary (卵卵房房) and discharges sperm near the embryo sac (胚囊胚囊)Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings An overview of angiosperm reproductionFigure 38.2a,

10、bAnther attip of stamenPollen tubeGerminated pollen grain(n) (male gametophyte)on stigma of carpelOvary (base of carpel)Ovule (卵胞卵胞)Embryo sac (n)(female gametophyte)FERTILIZATIONEgg (n)Sperm (n)KeyHaploid (n)Diploid (2n)(b) Simplified angiosperm life cycle.See Figure 30.10 for a more detailedversio

11、n of the life cycle, including meiosis.Mature sporophyteplant (2n) withflowersSeed(developsfrom ovule)Zygote(2n)Embryo (2n)(sporophyte)Simple fruit(develops from ovary)GerminatingseedSeedFilamentAntherStamenPetalReceptacleSepalStyleOvary(a) An idealized flower.CarpelStigmaCopyright 2005 Pearson Educ

12、ation, Inc. publishing as Benjamin Cummings(3) A pollen grain becomes a mature male gametophyte when its generative nucleus divides and forms two sperm. This usually occurs after a pollen grain lands on the stigma of a carpel and the pollen tube begins to grow. (See Figure 38.2b.) Development of a m

13、ale gametophyte (pollen grain)雄配子體雄配子體(花粉粒花粉粒)的發(fā)育的發(fā)育(a)(2) Each microsporocyte divides by meiosis to produce four haploid microspores (n), each of which develops into a pollen grain.Pollen sac(microsporangium)Micro-SporocyteMicro-spores (4)Each of 4microsporesGenerativecell (willform 2sperm)Nucleus

14、of tube cell(1) Each one of the microsporangia contains diploid microsporocytes (2n) (microspore mother cells).75 m20 mRagweedpollen grainFigure 38.4aMEIOSIS減數(shù)分裂減數(shù)分裂MITOSIS有絲分裂有絲分裂KEY to labelsHaploid (2n)Diploid (2n) Pollen (花粉花粉)-Develops from microspores (雄雄孢子孢子) within the sporangia (孢子囊孢子囊) of

15、anthersMaleGametophyte(pollen grain)Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsKey to labels有絲分裂有絲分裂MITOSIS減數(shù)分裂減數(shù)分裂MEIOSISOvuleOvuleIntegumentsEmbryo sacMega-sporangiumMega-sporocyteIntegumentsMicropyleSurvivingmegasporeAntipodelCells (3)PolarNuclei (2)Egg (1)Synergids (2)

16、 Development of a female gametophyte (embryo sac)雌配子體雌配子體(胚囊胚囊)的發(fā)育的發(fā)育(b)(1) Within the ovules megasporangium is a large diploid cell called the megasporocyte (megaspore mother cell).(3) Three mitotic divisions of the megaspore form the embryo sac, a multicellular female gametophyte. The ovule now co

17、nsists of the embryo sac along with the surrounding integuments (protective tissue).Female gametophyte(embryo sac)Diploid (2n)Haploid (2n)Figure 38.4b100 m(2) The megasporocyte divides by meiosis and gives rise to fourhaploid cells, but in most species only one of these survives as the megaspore. Em

18、bryo sacs-Develop from megaspores within ovulesCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsMechanisms That Prevent Self-Fertilization (自我受精自我受精) Many angiosperms (被子植物被子植物) Have mechanisms that make it difficult or impossible for a flower to fertilize itself (自我受精自我受精) Figu

19、re 38.5Stigma柱頭柱頭Anther withPollen 有花有花粉的花藥粉的花藥Stigma柱頭柱頭Pin flowerThrum flowerCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsThe most common anti-selfing mechanism in flowering plantsIs known as self-incompatibility (自我排斥、自我不相容自我排斥、自我不相容), the ability of a plant to reject its

20、 own pollenResearchers are unraveling the molecular mechanisms that are involved in self-incompatibilitySome plantsReject pollen that has an S-gene matching an allele in the stigma cellsRecognition of self pollen (自家花粉自家花粉)Triggers a signal transduction pathway leading to a block (阻礙阻礙) in growth of

21、 a pollen tubeCopyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 38.2: After fertilization, ovules develop into seeds and ovaries into fruitsCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsDouble Fertilization (雙重受精雙重受精)After landing on a receptive s

22、tigma (花柱花柱)A pollen grain (花粉?；ǚ哿? germinates and produces a pollen tube (花粉管花粉管) that extends down between the cells of the style () toward the ovary ()The pollen tube (花粉管花粉管)Then discharges two sperm into the embryo sacIn double fertilization (雙重受精雙重受精)One sperm fertilizes the eggThe other sperm

23、 combines with the polar nuclei (極核極核), giving rise to the food-storing endosperm (胚乳胚乳)Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsStigma (柱頭柱頭)(極核極核)Polar nucleiEgg(花粉?；ǚ哿?Pollen grainPollen tube (花粉管花粉管)2 spermStyleOvaryOvule (containing female gametophyte, or embryo sac

24、)MicropyleOvulePolar nucleiEggTwo sperm about to be dischargedEndosperm nucleus (3n) (2 polar nuclei plus sperm)Zygote (2n) (egg plus sperm)Figure 38.6 Growth of the pollen tube and double fertilization(1) If a pollen graingerminates, a pollen tubegrows down the styletoward the ovary.(2) The pollen

25、tubedischarges two sperm intothe female gametophyte(embryo sac) within an ovule.(3) One sperm fertilizes the egg, forming the zygote. The other sperm combines with the two polar nuclei of the embryosacs large central cell, forminga triploid cell that develops intothe nutritive tissue calledendosperm

26、.Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsDevelopment of Ovule and Endosperm From Ovule to Seed, after double fertilization Each ovule develops into a seed The ovary develops into a fruit enclosing the seed(s) Endosperm Development, usually precedes embryo development In

27、 most monocots and some eudicots, the endosperm stores nutrients that can be used by the seedling after germination In other eudicots, the food reserves of the endosperm are completely exported to the cotyledonsCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsEmbryo DevelopmentT

28、he first mitotic division of the zygote is transverseSplitting the fertilized egg into a basal cell and a terminal cellFigure 38.7OvuleTerminal cellEndosperm nucleusBasal cellZygoteIntegumentsZygoteProembryoCotyledonsShoot apexRoot apexSeed coatBasal cellSuspensorEndospermSuspensorCopyright 2005 Pea

29、rson Education, Inc. publishing as Benjamin CummingsStructure of the Mature Seed The embryo and its food supply Are enclosed by a hard, protective seed coat In a common garden bean, a eudicot The embryo consists of the hypocotyl, radicle, and thick cotyledonsFigure 38.8a(a) Common garden bean, a eud

30、icot with thick cotyledons. The fleshy cotyledons store food absorbed from the endosperm before the seed germinates.Seed coatRadicleEpicotylHypocotylCotyledons胚根胚根種皮種皮子葉子葉上胚軸上胚軸下胚軸下胚軸Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings The seeds of other eudicots, such as castor be

31、ans Have similar structures, but thin cotyledonsSeed coatEndospermCotyledonsEpicotylHypocotylRadicleFigure 38.8bSeed coatEndospermCotyledonsEpicotylHypocotylRadicle(b) Castor bean, a eudicot with thin cotyledons. The narrow, membranous cotyledons (shown in edge and flat views) absorb food from the e

32、ndosperm when the seed germinates.種皮種皮胚根胚根下胚軸下胚軸子葉子葉上胚軸上胚軸胚乳胚乳Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings The embryo of a monocot (單子葉單子葉) has a single cotyledon, a coleoptile, and a coleorhizaFigure 38.8c(c) Maize, a monocot. Like all monocots, maize has only one cotyledo

33、n. Maize and other grasses have a large cotyledon called a scutellum. The rudimentary shoot is sheathed in a structure called the coleoptile, and the coleorhiza covers the young root.Scutellum(cotyledon)ColeoptileColeorhizaPericarp fusedwith seed coatEndospermEpicotylHypocotylRadicle( (種皮種皮) )( (胚根胚

34、根) )( (下胚軸下胚軸) )( (上胚軸上胚軸) )( (胚乳胚乳) )( (子葉子葉) )( (芽鞘芽鞘) )( (根鞘根鞘) )Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsFrom Ovary to Fruit A fruit Develops from the ovary Protects the enclosed seeds Aids in the dispersal of seeds by wind or animalsCopyright 2005 Pearson Education,

35、 Inc. publishing as Benjamin Cummings Fruits are classified into several types Depending on their developmental originFigure 38.9ac (a) Simple fruit. A simple fruit develops from a single carpel (or several fused carpels) of one flower (examples: pea, lemon, peanut). (b) Aggregate fruit. An aggregat

36、e fruit develops from many separate carpels of one flower (examples: raspberry, blackberry, strawberry).(c) Multiple fruit. A multiple fruit develops from many carpels of many flowers (examples: pineapple, fig).Pineapple fruitRaspberry fruitPea fruitStamenCarpel(fruitlet)StigmaOvaryRaspberry flowerE

37、achsegmentdevelopsfrom thecarpel ofone flowerPineapple inflorescenceStamenCarpelsFlowerOvaryStigmaStamenOvulePea flowerSeedCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsSeed Germination (種子萌芽種子萌芽) As a seed matures It dehydrates (脫水脫水) and enters a phase referred to as dorman

38、cy (休眠休眠)Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsSeed Dormancy: Adaptation for Tough TimesSeed dormancyIncreases the chances that germination will occur at a time and place most advantageous to the seedlingThe breaking of seed dormancy Often requires environmental cues,

39、 such as temperature or lighting cuesFrom Seed to Seedling (從種子到幼苗從種子到幼苗) Germination of seeds depends on the physical process called imbibition (浸潤(rùn)浸潤(rùn))The uptake of water due to low water potential of the dry seedCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsFigure 38.10aCoty

40、ledonHypocotylRadicle(胚根胚根)Epicotyl (上胚軸上胚軸)Seed coat(種皮種皮)CotyledonHypocotylCotyledon (子葉子葉)Hypocotyl (上胚軸上胚軸)(a)Common garden bean. In common garden beans, straightening of a hook in the hypocotyl pulls the cotyledons from the soil.The radicle (胚軸胚軸) is the first organ to emerge from the germinati

41、ng seedIn many eudicots, a hook forms in the hypocotyl (下胚軸下胚軸), and growth pushes the hook above groundFoliage leaves (初生葉初生葉)( (上胚軸上胚軸) )( (上胚軸上胚軸) )Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsFoliage leavesColeoptileColeoptileRadicle(b) Maize. In maize and other grasses,

42、 the shoot grows straight up through the tube of the coleoptile.Monocots (單子葉植物單子葉植物)Use a different method for breaking ground when they germinateThe coleoptile (芽鞘芽鞘)Pushes upward through the soil and into the airFigure 38.10bCopyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings C

43、oncept 38.3: Many flowering plants clone (複複製製) themselves by asexual reproduction Many angiosperm species reproduce both asexually and sexually (無(wú)性及有性無(wú)性及有性) Sexual reproduction Generates the genetic variation that makes evolutionary adaptation possible Asexual reproduction in plants Is called veget

44、ative reproduction (營(yíng)養(yǎng)繁衍營(yíng)養(yǎng)繁衍)Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsMechanisms of Asexual Reproduction (無(wú)性生殖的機(jī)制無(wú)性生殖的機(jī)制)Fragmentation (裂片裂片)Is the separation of a parent plant into parts that develop into whole plantsIs one of the most common modes of asexual reproducti

45、on In some species, the root system of a single parent gives rise to many adventitious shoots that become separate shoot systemsFigure 38.11Copyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsVegetative Propagation (營(yíng)養(yǎng)繁衍營(yíng)養(yǎng)繁衍) and Agriculture Humans have devised various methods for

46、asexual propagation of angiosperms Clones from cuttings (切枝、切條切枝、切條) Many kinds of plants are asexually reproduced from plant fragments called cuttings Grafting (架接、接枝架接、接枝) In a modification of vegetative reproduction from cuttings A twig or bud from one plant can be grafted onto a plant of a close

47、ly related species or a different variety of the same speciesCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsTest-Tube Cloning (試管複製試管複製) and Related Techniques Plant biologists have adopted in vitro methods to create and clone novel plant varieties.Figure 38.12a, b(a) Just a f

48、ew parenchyma cells from a carrot gave rise to this callus, a mass of undifferentiated cells.(b) The callus differentiates into an entire plant, with leaves, stems, and roots.Copyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings In a process called protoplast fusion (原生原生質(zhì)體交融質(zhì)體交融) R

49、esearchers fuse protoplasts, plant cells with their cell walls removed, to create hybrid plantsFigure 38.1350 mVacuoleChloroplastCopyright 2005 Pearson Education, Inc. publishing as Benjamin Cummings Concept 38.4: Plant biotechnology is transforming agriculture Plant biotechnology has two meanings:

50、It refers to innovations in the use of plants to make products of use to humans It refers to the use of genetically modified organisms (GMO, 基因改造生物基因改造生物) in agriculture and industryCopyright 2005 Pearson Education, Inc. publishing as Benjamin CummingsArtificial Selection (人工選擇人工選擇; 人擇人擇)Humans have intervenedIn the reproduction and genetic makeup of plants for thousands of yearsMaize (玉米玉米) Is a product of artificial selection by humansIs a stap