文本講稿植物學(xué)

1、 IV. Development and structures of pistil 四、 雌蕊的發(fā)育與結(jié)構(gòu) position of pistil 雌蕊的組成 胚珠融合的邊緣Ventral suture柱頭子房Carpel is modified leaf 心皮是變態(tài)的葉子Pistil consists of one or more carpels and usually occupies the central position in the flower. In most angiosperms there is only one pistil in a flower comprised o

2、f one to five united carpels, but in some primitive angiosperms there may be several pistils (雌蕊）each comprised of a single carpel. Single pistil - from one carpel單雌蕊e.g. Fabaceae 豆科 (Leguminosae) Prunus (Rosaceae) 李屬（薔薇科）Cercis chinensis (Redbud 紫荊)Prunus Prunus salicina (李)Apocarpous gynoecium - f

3、rom more than one simple carpel but not united 離生心皮雌蕊群e.g. Magnoliaceae 木蘭科 Ranunculaceae 毛茛科 Rosoideae 薔薇亞科Magnolia denudata 白玉蘭Ranunculus japonicus 毛茛Duchesnea indica 蛇莓Syncarpous pistil - from more than one carpel but united - compound pistil 合生生心皮雌蕊 - 復(fù)雌蕊e.g. Most Angiosperm 大多數(shù)被子植物But there are

4、 different types: Dianthus sp. 石竹屬Syncarpous pistil - from more than one carpel but united - compound pistil 合生生心皮雌蕊 - 復(fù)雌蕊Polygonum sp. 蓼屬Gypsophila sp. 霞草屬Alternanthera sp. 蓮子草屬 2. Types of stigma 柱頭的類型 1 = stigma with multicellular trichomes（毛）; 2 = ovary wall; 3 = ovary locule （子房室）; 4 = perianth

5、 with tepals （花被萼片狀）; 5 = ovule; 6 = embryo sac; 7 = integuments （珠被）; 8 = hypostase 胚珠基; 9 = funiculus 珠柄; 10 = receptacle 花托 花筒=萼筒Wet stigma 濕柱頭 e.g. Nicotiana 煙草屬 Citrus 柑橘屬雌蕊成熟時(shí)柱頭上能產(chǎn)生許多液態(tài)分泌物，Dry stigma 干柱頭 Brassica 油菜屬 Gossypium 棉屬雌蕊成熟時(shí)沒有分泌物， 大多數(shù)被子植物的柱頭具有乳突(papilla), 具蛋白質(zhì)膜，能粘合花粉，識(shí)別作用 A sectional

6、 view of the wet stigma of lily (Lilium sp. 百合）showing a dense mat of hairs, a receptive surface for the pollen grains. The hairs secrete viscid substances (分泌黏液）that are involved in the recognition of compatible pollen（具有花粉識(shí)別功能）. If they fit together with the substances emanating from the pollen gr

7、ain wall, (親合的）pollen grains will germinate and produce normal pollen tubes （花粉管）. 1 = stigmatic hairs; 2 = ground parenchyma; 3 = stylar transmitting tissue ; 4 = stylar canal; 5 = exudate IV . Development and structures of pistil 雌蕊的發(fā)育與結(jié)構(gòu) 3. Types of style 花柱的類型Solid style 實(shí)心型 e.g. Gossynium 棉屬Hol

8、low style 空心型Lilium sp. 百合 3. Types of style 花柱的類型The style has solid pollen transmitting tissue (引導(dǎo)組織）O = ovary; Ovu = ovule; Sta = stamen; TrT = pollen transmitting tissue (solid);STG = stigma; STY = styleSolid style 實(shí)心型 e.g. Solanaceae 茄科 Poaceae 禾本科 3. Types of style Hollow style 花柱的類型：空心型 The L

9、ilium pistil has a hollow style. The pollen tubes grow to the ovary in contact with the glandular cells lining the stylar canal(花柱道). This pollen transmitting tissue (引導(dǎo)組織)consists of one layer of glandular cells, which secrete various hydrophilous and lipid substances involved in nourishment and gu

10、idance of the pollen tubes(涉及花粉管營養(yǎng)和引導(dǎo)）. 1 = stigmatic hairs; 2 = ground parenchyma; 3 = stylar transmitting tissue ; 4 = stylar canal; 5 = exudate 4. Structures of ovary 子房的結(jié)構(gòu) 1）Position of ovary 子房的位置There are three types of ovary positions:A) superior ovary 上位子房(e.g. tulip 郁金香) is situated on the

11、receptacle above the points of origin of the perianth (花被）parts and androecium（雄蕊群）； B) inferior ovary 下位子房(e.g. daffodil 水仙 ) is situated on the top of the ovary. Calyx, corolla, and androecium fused to form a flower tube, or hypanthium (花筒）; C) half-inferior ovary 半下位子房in which the hypanthium is a

12、dnate to only the lower half of the ovary. Flower bud of cherry (Prunus virginiana 櫻桃)In the cherry flower, a cup-like hypanthium is formed. However, the ovary is superior because the hypanthium does not e adnate to the ovary.花筒花筒未與子房愈合，仍為子房上位花周位1）Position of ovary 子房的位置2） Structures of ovary 子房的結(jié)構(gòu)O

13、vary wallOvary loculeOvulesPlacenta（胎座）Dorsa suture & bundle背縫線和背束Ventral suture & bundle腹縫線和腹束Lilium sp. ovary 百合子房橫切Placentae are variously positioned within the ovaries of different plants. 胎座在不同植物是變化的The type of placentation depends on the structure of the ovary. 胎座的類型取決于子房的結(jié)構(gòu)特立中央中軸側(cè)膜胎座類型對(duì)植物的分類是

14、重要的。Polycarpous ovary & parietal placentation in poppy 罌粟的多心皮子房與特殊的側(cè)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室子房的中軸胎座5. Structures and development of ovule 胚珠的結(jié)構(gòu)與發(fā)育Chalaza 合點(diǎn)Nucellus 珠心Embry

15、o sac 胚囊Outer integument外珠被Inner integument 內(nèi)珠被Micropyle 珠孔Funiculus 珠柄The most common type of megasporo- & megagameto-geneses show here is a bitegmic tenuinucellate anatropous ovule, appearing in the majority of plants.Development of ovule 胚珠的發(fā)育(1)最常見的大孢子發(fā)生類型是：雙珠被、薄珠心、倒生胚珠 DivisionA) Some cells nea

16、r ovary wall - - nucellus Ovule primordium 珠心 原基 - funiculus 珠柄B) both integuments 雙珠被develop bitegmic(nu = nucellus). Note the lack of the integuments(珠被). (ii = inner integument; oi = outer integument)Development of ovule 胚珠的發(fā)育(2)A big cell in nucellusstarts development Arehesporial孢原細(xì)胞A embryo-sa

17、c mother cell, EMC 胚囊母細(xì)胞Growth directly水稻、小麥、百合、向日葵等 Parietal cell周緣細(xì)胞Sporogenous cell造孢細(xì)胞crassinucellus厚珠心Mitosisembryo-sac mother cellMost plantsLilium sp.大多數(shù)被子植物是厚珠心的Megasporogenesis starts with meiotic division of the diploid megasporocyte 二倍的大孢子母細(xì)胞開始減數(shù)分裂Ends with the formation of tetrad of hapl

18、oid megaspores（單核胚囊）. Of tetrad spores (四分體）only a chalazal one （合點(diǎn)那個(gè)） es functional-other three degenerate.Development of ovule 胚珠的發(fā)育(3)EMCCarex sp. 莎草科苔屬Process of from EMC to tetrad spores in LiliumProcess of from EMC to tetrad spores in maize Types of megagametogenesis 大孢子發(fā)生的類型1) Polygonum type

19、蓼型(單孢型）In 70% agiosperme, tetrad spores (四分體）only a chalazal one （合點(diǎn)端那個(gè)） es functional Megasporo (大孢子），other three degenerate（解體）.Megasporo - 3 times of mitosis - 8 nucleus - mature (Single nuclear embryo sacembryo sac)Structure of mature embryo sac 成熟胚囊的結(jié)構(gòu)three antipodals 反足細(xì)胞 the central cell 中央細(xì)胞

20、Synergids助細(xì)胞 chalazal合點(diǎn)Micropylar 珠孔the eggOrthotropous crassinucellate bitegmic ovules in (Polygonum sp.) . 直生的雙珠被、厚珠心胚珠O = obturator, II = inner integument, OT = outer integument, S = synergids, N = nucellus (megasporangium), E = egg cell, SN = secondary nucleus of central cell, ES = embryo sac, A

21、 = antipodals, H = hypostase, C = chalaza, VB = vascular bundle, and F = funiculus Structure of mature embryo sac - megagametophyte成熟胚囊- 雌配子體的結(jié)構(gòu) Seven cells and eight nucleusAnatropous tenuinucellate 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 thre

22、e early developmental stagesCharacterization of mature Megagametophyte 成熟胚囊（雌配子體）的特化The antipodals （反足細(xì)胞） are variable. Central cell (中央細(xì)胞）has a big vacuole (液泡）, and polar nucleus sometime fused Into one secondary Nucleus (次生極核）. The egg cell and Synergids （助細(xì)胞）are highly polar.Synergids contain fi

23、liform apparatus （絲狀器吸器） 2）雙孢型胚囊， no tetrad3）四孢型胚囊， have a triploid nucleus ( antipodals and tetraploid polar nucleus)珠孔端退化Campylotropous tenuinucellate bitegmic ovules in spiderwort (Tradescantia sp.) 紫露草的彎生薄珠心、單珠被胚珠Identify： ovary wall, integuments and developing embryo sacs.Development of other e

24、mbryo sacsIn Calendula officinalis 金盞菊(Asteraceae) the fully mature and ready to be doubly fertilized embryo sac is 7-celled and 8-nucleate. Jin Section Eight Anthesis, pollination and fertilization第八節(jié) 開花、傳粉與受精I(xiàn) Anthesis 開花Concept: 花各部分成熟，花萼、花瓣開放，露出雌雄蕊的過程Smilacaceae 菝葜科植物 Calycanthus sp.夏臘梅Blooming

25、stage (開花期）：several days to some months;Flower lasting time (一朵花持續(xù)時(shí)間）: from several min. to some months.II Pollination 傳粉1. Self-pollination 自花傳粉e.g. wheat, rice, cotton, Citrus , peach, tomato, et al. Classical: cleistogamy 閉花受精e.g. pea 豌豆; barley 大麥;Broad sense (廣義的): In crops, different flowersin

26、 same individual or even between flowers from different individuals. Concept: 雄蕊的花粉借助外力傳到雌蕊柱頭的過程2. Cross-pollination 異花傳粉：process that pollens from one flower are transferred to stigma of another flowers. It is a evolutionary character. 是進(jìn)化的特征。 1) Adaptation to cross-pollination 植物對(duì)異花傳粉的適應(yīng)Corn (Zea)

27、 is a Monoecious （雌雄同珠）plant1) Adaptation to cross-pollination 植物對(duì)異花傳粉的適應(yīng)Stamens first mature in sunflower, pear and apple. Primula flower 報(bào)春花屬1) Adaptation to cross-pollination 植物對(duì)異花傳粉的適應(yīng)Primula sp. 報(bào)春花屬1) Adaptation to cross-pollination 植物對(duì)異花傳粉的適應(yīng)(4) Self-sterility 自花不孕One case is that pollens can

28、not germinate on the stigma, e.g. sunflower.花粉不能萌發(fā)；Another case is that pollentube of self-pollen grows slowly.花粉管生長慢2) Medium of cross-pollination 異花傳粉的媒介Wind, - Anemophilous flowers or plants風(fēng)媒花及風(fēng)媒植物e.g. Gymnosperme 裸子植物；Poaceae 禾本科Juglandaceae 胡桃科；Ulmaceae 榆科Myridaceae 楊梅科 Betula 樺屬Lack of perian

29、th (花被）or reduce，F(xiàn)ilament longer, pollens small and light, and stigma (柱頭）bigger. Characters of anemophilous flowers in Poaceae禾本科風(fēng)媒花特征2）Medium of cross-pollination 異花傳粉的媒介(2) Insects - entomophilous flowers or plants蟲媒花及蟲媒植物Paeonia sp. 芍藥屬A bumblebee on a Aster sp. Inflorescence 紫菀屬植物Characters of

30、entomophilous flowers 蟲媒花特征Beetles (甲蟲）in a flowerOf Hydnora sp（食菌屬）.Hawkmoth and Lonicera sp.天蛾與忍冬植物 Flowers are bigger and beautiful color, smell and bectary; pollen is bigger. 色、氣味、蜜腺等 Wasplike flower of Ophrys像黃蜂一樣的蘭花Spider and Orchids flower蜘蛛蟹與蘭花With a large landing platformDifferent entomophi

31、lous flowers 各式各樣的蟲媒花Mint, 薄荷Wasp and zebra orchid黃蜂與斑馬蘭2）Medium of cross-pollination 異花傳粉的媒介(3) Bird-pollinated flowers鳥媒花Honeyeater and bell-fruited mallee;蜜雀和鐘果桉（澳大利亞）A hummingbird and Fuchsia蜂鳥與倒掛金鐘花（柳葉菜科）2）Medium of cross-pollination 異花傳粉的媒介(4) mammal-pollinated flowers哺乳動(dòng)物傳粉植物A short-nosed bat

32、 and Bonana短鼻蝙蝠和香蕉樹A tihy australian honey-possumAnd coral gum (Eucalyptus sp.)澳大利亞蜜鼠和按樹2）Medium of cross-pollination 異花傳粉的媒介(3) water-pollinated plants水媒植物A aquatic ribbon weed ( Vallisneria sp.) release their flowers as “pollen boats” 水生的苦草屬植物A large female flowerDifferent flowers Insects eye 昆蟲的眼

33、睛Flowers of the evening primrose ( Oenothera， 月見草) are uniform in color to the human eye，but insects see a different pattern in UV light (紫外光）. III Fertilization 受精Concept: (1) Pollens germinate and the pollen tube growsRecognition and germination on stigma在柱頭上識(shí)別并萌發(fā)Generative cell divides into two s

34、perms (精子）in tube.70% angiosperm belongs to thispattern.Three cells pollen in some plantsIII Fertilization 受精(1) Pollens germinate and the pollen tube growsRice, Oryza sativaIII Fertilization 受精(2) pollen tube grows into the ovary 花粉管進(jìn)入子房Pathway 途徑: from micropylar mostly - porogamy 珠孔受精chalazal合點(diǎn)ch

35、alazogamy合點(diǎn)受精 e.g. Juglans 胡桃屬mesogamy 中部受精the tube into ovary betweenChalazal and micropylar, e.g. Cucubita 南瓜屬但是，最后都經(jīng)助細(xì)胞進(jìn)入胚囊Two spermsCharecters of double fertilization 雙受精特點(diǎn)Triploid primary endosperm nucleus (3X初生胚乳核） in Calendula officinalis 金盞菊: （1）花粉管從退化助細(xì)胞絲狀器進(jìn)入胚囊2個(gè)精細(xì)胞 助細(xì)胞先端小孔1個(gè)營養(yǎng)核 釋放到卵細(xì)胞與 胼胝質(zhì)

36、塞孔中央細(xì)胞之間 阻止流動(dòng) One spermAnother sperm一個(gè)與卵細(xì)胞的無壁區(qū)接近并融合 合子另一個(gè)與極核接近并融合 zygoteFinish double fertilizationSignificance of double fertilization 雙受精意義 雙受精是被子植物所特有的現(xiàn)象。兩個(gè)染色體單倍的精卵細(xì)胞的融合，把父、母雙親的遺傳物質(zhì)重新組合，形成了兼有父母雙重遺傳性的合子；形成了三倍體的初生胚乳核，同樣兼有父、母本的遺傳特 性，子代變異性更大，生活力更 強(qiáng)，更適應(yīng)環(huán)境的變化。 Influence of environment on pollination an

37、d fertilization環(huán)境條件對(duì)傳粉、受精的影響Inner factors: 花粉敗育或雄性不育、花粉粒與雌蕊柱頭間 的不親和性以及植株?duì)I養(yǎng)不良等引起。Outer factors: 氣候條件、栽培措施和環(huán)境污染等。受精的 最適溫度是2630oC，最適濕度為70 80% Section Nine forming, structure and development 第九節(jié) 種子的形成、結(jié)構(gòu)及生長發(fā)育 After fertilization, zygote (合子）develops into embryo（胚）, and primary endosperm nucleus （初生胚乳核）

38、into Endosperm（胚乳）, then Integument （珠被） es seed coat.Two-celled embryo: Difference in Ultrastructure between terminal & basal cellsProembryo protrudes into endosperm.2細(xì)胞原胚 1. development of embryo 胚的發(fā)育 The zygote has a short resting stage (休眠期)，then unequally divides into two cells: terminal & basa

39、l cells （頂細(xì)胞和基細(xì)胞） Embryo normally originates from longitudinal (vertical) division of terminal cell.頂細(xì)胞縱裂發(fā)育-胚體Suspensor (胚柄）is derived from basal cell. development of embryo 胚的發(fā)育Proembryo 原胚期Proembryo 原胚期development of embryo 胚的發(fā)育Further transverse and longitudinal divisions result in octant formati

40、on (8細(xì)胞原胚期）. Cell divisions in suspensor completedThe suspensor has grown into a long filament of ten cells. Note outer (oi) and inner (ii) integuments, precursors of seed coat, endosperm vacuole (ev), and basal cell (bc).Electron micrograph of the octant embryo 八分體胚囊的電鏡結(jié)構(gòu)1 = portion of endosperm va

41、cuole; 2 = very thin layer of the endosperm cytoplasm surrounding the embryo; 3 = endosperm chloroplasts; 4 = upper suspensor cell最頂端的胚柄細(xì)胞 16-celled embryodevelopment of embryo 胚的發(fā)育Proembryo 原胚期Globular stage: 球形胚階段Beginning of procambiumUpper suspensor cell produces hypophysis (胚軸）Nuclear type of e

42、ndosperm development 核型胚乳發(fā)育development of embryo Proembryo 原胚期 胚的發(fā)育1 = a portion of endosperm central vacuole; 2 = endothelium of the inner integument; 3 = embryoderm; 4 = cells of the future procambium; 5 = hypophysis; 6 = endosperm free nuclei 游離胚乳核; 7 = suspensor Globular stage under EM 電鏡下的球形胚階段

43、Cordate (heart-shaped) embryo: cotyledons Develop 心形胚2. Development of embryo after proembyo in Dicots 雙子葉植物原胚期后，胚的發(fā)育Late cordate embryo， 晚心形胚2. Development of embryo after proembyo in Dicots 雙子葉植物原胚期后，胚的發(fā)育“Torpedo embryo:” 魚雷形胚The beginning of hypocotyl elongation 胚軸伸長Endosperm cellularization 胚乳細(xì)胞

44、開始形成Early bending cotyledon stage of embryo development.Shoot & root apical meristems are discernible （可見頂端分生組織）Mature seed and embryo:成熟種子和胚 Embryo fills space enclosed within seed coat.Integuments transformed into seed coat.珠被形成種皮2. Development of embryo after proembyo in Dicots 雙子葉植物原胚期后，胚的發(fā)育1 =

45、shoot apical meristem; 2 = seed coat; 3 = cotyledon; 4 = procambium; 5 = hypocotyl; 6 = pericarp (fruit wall); 7 = radicle (embryonic root); 8 = basal cell of suspensor; 9 = funiculus Diagrammatic review of Capsella （薺菜）embryogenesis Nicotiana （煙草）embryogenesis: Embryo proper originates from transve

46、rse (horizontal) division of terminal cell 3. Development of embryo after proembyo in Monocots 單子葉植物原胚期后，胚的發(fā)育Embryogenesis in monocots: Sagittaria （澤瀉）Single cotyledon is on top of the embryo Reduced cotyledon3. Development of embryo after proembyo in Monocots 單子葉植物原胚期后，胚的發(fā)育 1 3A 2 B C 3 4 4 5 7 8 9

47、 6 D 梨形胚一片子葉退化子葉4. Development of endosperm 胚乳發(fā)育核型胚乳 (nuclear type) 細(xì)胞型胚乳(cellular type) Solanaceae 茄科沼生目胚乳(helobial type)慈菇、獨(dú)尾草屬（Eremurus sp.） 1 2 3 A B C D介于核型與細(xì)胞型之間。特點(diǎn)：初生胚乳核第一次分裂后，胚囊分離成二室：珠孔室（較大）和合點(diǎn)室（較小）。此后，每室（主要是珠孔室）分別進(jìn)行幾次游離核的分裂。 5. prosembryum 外胚乳 胚囊外圍的珠心組織遭到破壞，最后為胚和胚乳所吸收，故在多數(shù)植物成熟的種子中沒有珠心組織。但少數(shù)植物的珠心組織始終