植物学课程课件2012

1、Section 7 Morphology, structure and development of flower 第七节 花的形态、结构及生长发育 The flower is a characteristic system of reproductive organs of angiosperms (syn. flowering plants) in which two basic processes of sexual reproduction, meiosis and the fusion of male and female gametes occur resulting in the

2、 production of a new generation, the embryo. 1. Morphology of flowers 花的形态学 花是被子植物的生殖器官，是适应于生殖的变态短枝，花的各部分为变态叶。1.1 花的组成 花梗 花托 花萼 花冠 雄蕊群 雌蕊群 禾本科植物花的组成（单子叶） 外颖 颖片（小总苞） 内颖 外稃（苞叶） 稃片 小穗 内稃（小苞叶） 花（1几朵） 浆片（花被）穗 雄蕊群 雌蕊群 小穗轴 穗轴 小 麦 穗、小 穗、花 的 组 成穗小穗花小穗穗轴小穗轴外颖内颖小花浆片外稃内稃雌蕊雄蕊其它单子叶植物的花:1.2 花的类型* 离萼 合萼 副萼 * 离瓣 合瓣

3、无瓣 * 双被 单被 无被 * 两性 单性 无性1.3 花的对称性： *辐射对称花：花瓣或花被片排列整齐，过花心可作2多个对称面的花。-整齐花 *两侧对称花：花瓣或花被片排列不整齐，但过花心能作一个对称面的花。-不整齐花 *不对称花：通过花心不能作出对称面的花。-不整齐花辐射对称两侧对称1.4 花冠形态头状花序中的舌状花和管状花1.5 雄蕊形态1. 6 雌蕊形态1. 7 子房形态1. 8 胎座形态 2. Flower bud differentiation and development 花芽分化和发育 1234桃花芽分化1. 萼片原基； 2. 花瓣原基； 3. 雄蕊原基； 4. 雌蕊原基一种

4、毛茛花芽在雌蕊形成初期的分生组织 1 = sepal primordium;萼片2 = petal primordium;花瓣3 = stamen primordium;雄蕊4 = carpel primordial;心皮5 = procambium；原形成层 Floral organ development in periwinkle (Vinca minor) 长春花的花芽分化 Floral organ development under SEM 扫描电镜下的花芽分化 Inflorescences are initiated in a floral apex in the same acr

5、opetal sequence as in flowers. 花序的分化也是向上的.showing the initiation and early developmental stages of a compound umbel （复伞形花序）and its flowers in carrot (Daucus carota 胡萝卜Pattern of inflorescence and flowers development in the head. 头状花序The youngest flowers are in the center found in Calendula officinal

6、is（金盏菊）Note the unusually wide meristem.Pattern of inflorescence and flowers development in complex spike. 复穗状花序和花发育的模式A生长锥；B. 生长锥伸长期;C.苞原基分化期（单棱期）; D. 小穗分化期开始; E. 小穗分化期末期;F. 颖片分化期; G. 小花分化期; H. 一个小穗（正面观）;I.雄蕊分化期;J.雌蕊形成期. 1.苞片原基;. 小穗原基;. 颖片原基;. 小花原基;. 雄蕊原基;.雌蕊原基 3 . Structure and development of stam

7、en 雄蕊的结构与发育 3. 1 Origin of stamens - modified leaves 雄蕊的起源 - 变态的叶子 Cross-sectional view of gooseberry （Ribes sp.） flower, showing anthers parts醋栗花横切示花药结构Five anthers, each with four pollen sacs (花粉囊） (microsporangia， 小孢子囊), bearing pollen grains are shown. 1 = connective; 药隔2 = anther vascular bundl

8、e; 花药维管束3 = pollen sac wall; 花粉囊壁4 = style; 花柱5 = petal; 花瓣6 = sepal 萼片3. 2 Structure and development of anther 花药的发育与结构A-E. 花药的发育过程；F. 一个花粉囊放大，示花 粉母细胞;G. 已开裂的花药，示花药 的构造1.原表皮；2.孢原细胞；3.造孢细胞；4.药室内壁（纤维层）5.绒毡层；6.中层；7.花粉母细胞；8.药隔维管束；9.药隔基本组织； 10.花粉粒; 11. 表皮10Development process of microgametophyte of flow

9、ering plants 有花植物雄配子体发育过程（1）表皮药隔基本组织药隔维管束药室内壁中层绒毡层花粉母细胞未 成 熟 花 药 的 结 构a、表皮； b、药室内壁； c、中层； d、绒毡层 Development process of microgametophyte of flowering plants 有花植物雄配子体发育过程（2）药隔维管束表皮药隔基本组织花粉粒纤维层成 熟 花 药 的 结 构3. 3 花粉母细胞发育形成花粉粒1） Meiosis 减数分裂花粉母细胞小孢子四分体四分体：田字型四分体四面体型四分体2）花粉粒的发育3）成熟花粉粒的结构4）成熟花粉粒的类型二胞花粉粒三胞花粉

10、粒扫描电镜下的花粉粒形态3. 4 Activity of pollen and pollen Tube 花粉活力与花粉管活力 与植物的遗传有关，但受环境影响 ，低温有利于其活力的保存。Pollen plants花粉植物 4. Development and structures of pistil 雌蕊的发育与结构 4.1 雌蕊的起源心皮 Carpel is modified leaf 心皮是变态的叶子1） Single pistid - from one carpel 单雌蕊（单心皮）e.g. Fabaceae 豆科 (Leguminosae) Prunus (Rosaceae) 李属（蔷薇

11、科）Cercis chinensis (Redbud 紫荆)Prunus Prunus salicina (李)2）Apocarpous gynoecium - from more than one simple carpel but not united 离生心皮雌蕊群e.g. Rosoideae 蔷薇亚科 Magnoliaceae 木兰科Ranunculaceae 毛茛科 Magnolia denudata 白玉兰Ranunculus japonicus 毛茛Duchesnea indica 蛇莓3）Syncarpous pistil - from more than one carpel

12、 but united - compound pistil 合生心皮雌蕊 - 复雌蕊e.g. Most Angiosperm 大多数被子植物But there are different types: Dianthus sp. 石竹属3）Syncarpous pistil - from more than one carpel but united - compound pistil 合生心皮雌蕊 - 复雌蕊Polyponum sp. 蓼属Gypsophila sp. 霞草属Alternanthera sp. 莲子草属11231231231、柱头；2、花柱；3、子房 1) 柱头：雌蕊顶端接受花

13、粉的部位；其表皮细胞向外伸长成 毛状，称乳突细胞。 2) 花柱 ：连接柱头与子房，是花粉管到达子房的通道。 3) 子房 ：雌蕊基部膨大的部分，由子房壁、子房室、胎座 和胚珠组成。柱头花柱子房4.2 Composition of pistil 雌蕊的结构组成Wet stigma 湿柱头 e.g. Nicotiana 烟草属 Citrus 柑橘属Dry stigma 干柱头 Brassica 油菜属 Gossypium 棉属Types of style柱头类型Types of style花柱的类型Solid style 实心型 e.g. Gossynium 棉属Hollow style 空心型Ci

14、trus 柑橘属花柱道花柱沟引导组织Structures of ovary 子房的结构 Position of ovary 子房的位置There are three types of ovary positions:A superior ovary (e.g. tulip 郁金香) is situated on the receptacle above the points of origin of the perianth parts and androecium（雄蕊群）. In an inferior ovary (e.g. daffodil 水仙 ) the other floral

15、parts are attached at the top of the ovary. Calyx, corolla, and androecium fused to form a flower tube, or hypanthium (花筒）. Some plants (e.g. Sambucus 接骨木) is a half-inferior ovary in which the hypanthium is adnate to only the lower half of the ovary. 子房的结构：Ovary wall（子房壁）Ovary locule（子房室）Ovules（胚珠）

16、Placenta（胎座）Dorsa suture & bundle背缝线和背束Ventral suture & bundle腹缝线和腹束Lilium sp. ovary 百合子房横切子房壁子房室胎座胚珠子 房 横 切 面 结 构棉 属Placentae are variously positioned within the ovaries of different plants.The type of placentation depends on the structure of the ovary.特立中央中轴侧膜胎座类型对植物的分类是重要的。Polycarpous ovary & par

17、ietal placentation in poppy 罂粟的多心皮子房与特殊的侧膜胎座Fused margins of numerous carpels grow deeply into a one-locular ovaryCentral-angular placentation in bilocular ovary and in trilocular ovary 2室子房和3室子房的中轴胎座4. 3 Structures and development of ovule 胚珠的发育与结构Chalaza 合点Nucellus 珠心Embryo sac 胚囊Outer integument外

18、珠被Inner integument 内珠被Micropyle 珠孔Funiculus 珠柄The most common type of megaspore- & megagameto-geneses show here is a bitegmic tenuinucellate anatropous ovule, appearing in the majority of plants.1）Development of ovule 胚珠的发育(1)最常见的大孢子发生类型是：双珠被、薄珠心、倒生胚珠 DivisionSome cells near ovary wall - - nucellusO

19、vule primordium 珠心 - funiculus 珠柄both integuments 双珠被develop bitegmic(nu = nucellus). Note the lack of the integuments. (ii = inner integument; oi = outer integument)2）Development of ovule 胚珠的发育(2)A big cell in nucellusstarts development Arehesporial孢原细胞A embryo-sac mother cell, EMC 胚囊母细胞Growth dire

20、ctlyParietal cell周缘细胞Sporogenous cell造孢细胞crassinucellus珠心Mitosisembryo-sac mother cellMost plantsLilium sp.Megasporegenesis starts with meiotic division of the diploid megasporecyte 二倍体大孢子母细胞开始减数分裂Ends with the formation of tetrad of haploid megaspores（单核胚囊）. Of tetrad spores (四分体）only a chalazal on

21、e （合点那个） es functional-other three degenerate.3）Development of ovule 胚珠的发育(3)EMCCarex sp. 莎草科苔属Process of from EMC to tetrad spores in LiliumProcess of from EMC to tetrad spores in ZeaTypes of megasporogenesis 大孢子发生的类型Polygonum type 蓼型(单孢型）In 70% angiosperme, tetrad spores (四分体）only a chalazal one （

22、合点端那个） es functional Megaspore (大孢子），other three degenerate点（解体）.Megaspore - 3 times of mitosis - 8 nucleus - mature (Single nuclear embryo sacembryo sac)seven cells embryo sac includes the egg and two synergids (representing the egg apparatus in the micropylar region of the sac), the central cell a

23、nd, in the chalazal region, three antipodals. Structure of mature embryo sac 成熟胚囊的结构three antipodals 反足细胞 the central cell 中央细胞Synergids助细胞 chalazalmicropylarthe eggOrthotropous crassinucellate bitegmic ovules in (Polygonum sp.) . 直生的双珠被、厚珠心胚珠O = obturator, II = inner integument, OT = outer integume

24、nt, S = synergids, N = nucellus (megasporangium), E = egg cell, SN = secondary nucleus of central cell, ES = embryo sac, A = antipodals, H = hypostase, C = chalaza, VB = vascular bundle, and F = funiculus Structure of mature embryo sac - megagametophyte成熟胚囊- 雌配子体的结构 Seven cells and eight nucleusAnat

25、ropous tenuinucellate unitegmic ovule in sedge莎草的倒生薄珠心胚珠The drawing portrays structural changes of a sedge (Carex sp.) ovule at three early developmental stagesCharacterization of mature Megagametophyte 成熟胚囊（雌配子体）的特化Synergids contain filiform apparatusThe egg cell and Synergids are highly polar.Cent

26、ral cell has a big Vacuole (液泡）, and polar Nucleus sometime fused intoone secondary nuceus. The antipodals are variable. 双孢型胚囊， no tetrad四孢型胚囊， have a triploid nucleus ( antipodes and polar nucleus)Campylotropous tenuinucellate bitegmic ovules in spiderwort (Tradescantia sp.) 紫露草的弯生薄珠心、双珠被胚珠Identify

27、： ovary wall, integuments and developing embryo sacs.Development of other embryo sacsIn Calendula officinalis 金盏菊(Asteraceae) the fully mature and ready to be doubly fertilized embryo sac is 7-celled and 8-nucleate. 直生弯生横生Section 8 Anthesis, pollination and fertilization第八节 开花、传粉与受精1. Anthesis 开花花中雌

28、、雄蕊成熟时，花萼、花冠开放露出雌、雄蕊的现象。 开花期（Blooming stage） ： 一株植物上第一朵花开放到最后一朵花开毕所经历的时间。Calycanthus sp.夏腊梅2. Pollination 传粉2.1 Self-pollination 自花传粉pollens are transferred to stigma of same flowers.e.g. wheat, rice, cotton, Citrus , peach, tomato, et al. Classical: cleistogamy 闭花受精e.g. pea 豌豆; barley 大麦; Concept:

29、process that pollens from one flower are transferred to stigma of another flowers. 2.2 Cross-pollination 异花传粉：In crops, different flowers in same individual or even in one cultivar between flowers from different individuals.It is a evolutionary character. 是进化的特征。 2.3 Adaptation to cross-pollination

30、植物对异花传粉的适应Corn (Zea) is a Monoecious plantAdaptation to cross-pollination 植物对异花传粉的适应Stamens first mature in sunflower, pear and apple. Primula flower 报春花属Adaptation to cross-pollination 植物对异花传粉的适应Primula sp. 报春花属Adaptation to cross-pollination 植物对异花传粉的适应(4) Self-sterility 自花不孕One case is that pollen

31、s cannot germinate on the stigma, e.g. sunflower.花粉不能萌发；Another case is that pollentube of self-pollen grows Slowly.花粉管生长慢2.4 Medium of cross-pollination 异花传粉的媒介Wind, - Anemophilous flowers or plants风媒花及风媒植物e.g. Gymnosperme 裸子植物；Poaceae 禾本科Juglandaceae 胡桃科；Ulmaceae 榆科Myridaceae 杨梅科 populus 杨属；Betula

32、 桦树Lack of perianth (花被）or reduce，Filament longer, pollens small and light, and stigma (柱头）bigger. Characters of anemophilous flowers in Poaceae禾本科风媒花特征Medium of cross-pollination 异花传粉的媒介(2) Insects - entomophilous flowers or plants虫媒花及虫媒植物Paeonia sp. 芍药属A bumblebee on a Aster sp. Inflorescence 紫菀属植

33、物Characters of entomophilous flowers 虫媒花特征Beetles (甲虫）in a flowerOf Hydnora sp.Hawkmoth and Lonicera sp.天蛾与忍冬植物 Flowers are bigger and beautiful color, smell and bectary; pollen is bigger. 色、气味、蜜腺等 Wasplike flower of Ophrys像黄蜂一样的兰花Spider and Orchids flower蜘蛛蟹与兰花With a large landing platformDifferent

34、 entomophilous flowers 各式各样的虫媒花Mint, 薄荷Wasp and zebra orchid黄蜂与斑马兰Medium of cross-pollination 异花传粉的媒介(3) Bird-pollinated flowers鸟媒花Honeyeater and bell-fruited mallee;蜜雀和钟果桉（澳大利亚）A hummingbird and Fuchsia蜂鸟与倒挂金钟花（柳叶菜科）Medium of cross-pollination 异花传粉的媒介(4) mammal-pollinated flowers哺乳动物传粉植物A short-nos

35、ed bat and Bonana短鼻蝙蝠和香蕉树A tihy australian honey-possumAnd coral gum (Eucalyptus sp.)澳大利亚蜜鼠和桉树Medium of cross-pollination 异花传粉的媒介(5) water-pollinated plants水媒植物A aquatic ribbon weed ( Vallisneria sp.) release their flowers as “pollen boats” 水生的苦草属植物A large female flower Insects eye 昆虫的眼睛Flowers of t

36、he evening primrose ( Oenothera) are uniform in color to the human eye，but insects see a different pattern in UV light (紫外光）. 3. Fertilization 受精Concept:The fusion of sperm and egg. (1) Pollens germinate and the pollen tube growsRecognition and germination on stigma在柱头上识别并萌发Generative cell divides i

37、nto two sperms (精子）in tube.70% angiosperm belongs to thispattern.Three cells pollen in some plants(2) pollen tube grows into the ovary 花粉管进入子房Pathway 途径: from micropylar mostly - porogamy 珠孔受精chalazal合点chalazogamy合点受精 e.g. Juglans 胡桃属mesogamy 中部受精the tube into ovary betweenChalazal and micropylar, e

38、.g. Cucubita 南瓜属(3) Charecters of double fertilization 双受精特点in Calendula officinalis: Triploid primary endosperm nucleus Two spermsSignificance of double fertilization 双受精意义 双受精是被子植物所特有的现象。 两个染色体单倍的精卵细胞的融合，把父、母双亲的遗传物质重新组合，形成了兼有父母双重遗传性的合子；形成了三倍体的初生胚乳核，同样兼有父、母本的遗传特性，子代变异性更大，生活力更强，更适应环境的变化。Influence of

39、 environment on pollination and fertilization环境条件对传粉、受精的影响Inner factors: 花粉败育或雄性不育、花粉粒与雌蕊柱头间的不亲和性以及植株营养不良等引起。Outer factors: 气候条件、栽培措施和环境污染等。受精的最适温度是2630oC，最适湿度为7080%。受精后子房及胚珠各结构部分的发育 子房壁 果皮 子房室 胎座子房 珠柄 种柄 合点 珠被 种皮 珠心 消失或成外胚乳 胚珠 反足细胞 消失 中央细胞（2个极核） 受精 受精极核 胚乳 胚囊 卵细胞（雌配子） 受精 受精卵 胚 助细胞 消失 珠孔 种孔Section 9 Forming, Structure and Development of Seeds第九节 种子的形成、结构及生长发育After fertilization, zygote (合子）develops into embryo（胚）, and primary endosperm nucleu