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1.
狗枣猕猴桃果实发育的解剖学观察   总被引:2,自引:0,他引:2  
对狗枣猕猴桃果实发育进行了显微和超微结构观察。其主要过程可分为:1、早期胚胎发育;多心皮合生子房,通常具16个心室,中轴胎座,中轴上着生大量倒生胚珠,单珠被,具珠被绒毡层,胚囊蓼型,授粉后约2-4h花粉萌发,授粉后约120h花粉管到达胚珠,受精后,初生胚乳核分裂先于合子。胚乳发育为细胞型。2、果壁:果壁可分为果皮,果肉和果心三部分,果皮较薄,由2-3层薄壁细胞组成。外表面光滑无毛,但覆有角质层,气孔下陷,分布于其中,果肉的大部分由薄壁细胞组成,分大,小两种细胞,小细胞含较多淀粉粒,淀粉粒的水解是果实软化的原因之一。果肉薄壁组织细胞还含有叶绿体及两种异细胞,一种异细胞内含物为结晶,普遍存在;另一种含被番红染成红色的絮团状物。果心由维管束和薄壁细胞组成,维管束不发达,3、种子:种皮外表面呈蜂窝状,种皮较硬,由两层细胞构成。线性直立胚,胚乳发达,主要贮藏物是蛋白质。  相似文献   

2.
采用常规石蜡切片法对伞形科(Apiaceae)芹亚科(Apioideae Drude)芫荽属(Coriandrum Linn.)种类芫荽(Coriandrum sativum Linn.)花后幼果发育阶段和果熟发育阶段的果实横切面解剖结构及其变化进行了观察和比较。观察结果表明:芫荽果实的幼果和果熟发育阶段均分为前期、中期和后期3个时期,不同时期果实横切面的形状和大小、果壁厚度和结构以及合生面、果棱、维管束、油管、胚乳和结晶等特征均有明显变化。在芫荽果实发育过程中,果实横切面由近椭圆形逐渐变为近圆形,且分生果长度从1 630μm增加至3 290μm、宽度从860μm增加至1 580μm。合生面长度与分生果长度相等,但合生面逐渐分离,成熟的2个分生果仅由心皮柄维管束和合生面两端的外果壁及中果壁最外侧数层细胞相连,从外形看2个分生果不分离。果壁由薄变厚、再由厚变薄,明显分为4个层次;成熟果实的中果壁大部分由木化细胞构成。果棱可分为主棱和次棱2种,且均不发达;次棱呈角状突起、主棱呈波状弯曲,次棱较主棱明显。维管束包括果壁维管束、心皮柄维管束和种脊维管束3类,其中,果壁维管束不发达且散布于中果壁木化细胞层中。油管仅存在于合生面并被逐渐压扁,而果壁油管消失并转变成大空腔。胚乳逐渐膨大,其形状由元宝形逐渐转变为船形或肾形。此外,在幼果发育阶段,中果壁薄壁细胞、合生面和胚乳细胞中或多或少都含有结晶,胚乳细胞中还含有大量糊粉粒结晶;但在果熟发育阶段结晶消失,仅胚乳细胞中存有糊粉粒结晶。分析结果显示:芫荽果实属隐性双悬果类型且果棱属微果棱型,其部分解剖结构与伞形科芹亚科多数种类的果实有差异。  相似文献   

3.
窝梨果实结构及发育的研究   总被引:9,自引:0,他引:9  
窝梨果实是由托杯和子房共同发育形成的假果,其横切面上,由外向内可看到表皮层,果肉,果心等几部分。表皮层,果肉由托杯发育而来,其中发布着维管束及石细胞等,果心是由子房发育而成,子房下位,5心皮组成5室,每室具2个倒生胚珠。  相似文献   

4.
对苏铁(Cycas revoluta Thunb.)种子的种皮进行了解剖研究,结果表明:苏铁种子的种皮分为外种皮、中种皮和内种皮3层结构.外种皮含有角质化的表皮细胞、薄壁细胞以及少量的厚壁细胞和异细胞,布有树脂道、气室和4束大维管束;中种皮主要由厚壁细胞群和木质化纤维组成,种孔端有一条缝合线,种脐端有3个孔;内种皮由多层干瘪的薄壁细胞和脉络状维管束组成,种孔端有一层椭圆状保护膜.对外种皮和内种皮维管束进行观察研究发现:外种皮和内种皮的维管束分布方式及其结构存在明显差异,外种皮的维管束由种脐端顺着种子弧形走向种孔端,内种皮的维管束呈脉络状,形成维管网贯穿其中;内、外种皮维管束中均存在多种不同样式的导管.  相似文献   

5.
九翅豆蔻种子的解剖学和组织化学研究   总被引:11,自引:0,他引:11  
九翅豆蔻种子包括假种皮、种皮、外胚乳、内胚乳和胚.由外珠被发育而来的种皮可划分为外种皮、中种皮和内种皮.外种皮由一层表皮细胞构成,其壁增厚并略木质化.中种皮包括下皮层、油细胞层和含2—5层细胞的色素层;各为一层薄壁细胞的下皮层与油细胞层非常压扁.内种皮由一层石细胞构成,极厚,占种皮厚度的1/3—2/3,是种皮主要的机械层;内种皮整体外观呈波浪形,在珠孔端和合点端的内种皮除外.种子在珠孔端分化出珠孔领和孔盖,在合点端分化出下皮细胞垫、大型薄壁细胞区、维管束和合点端色素细胞区.外胚乳细胞内充满淀粉,内胚乳细胞含有大量蛋白质和多糖,胚细胞含有蛋白质、多糖和脂类物质.脂类物质不存在于油细胞中,而存在于胚细胞、部分假种皮细胞、外种皮细胞和内胚乳最外层细胞中.建议将油细胞(层)改称为半透明细胞(层).  相似文献   

6.
对中国伞形科(Apiaceae)特有种类明党参(Changium smyrnioides Wolff)花后果实发育过程中果实横切面的解剖结构变化进行了比较观察.结果表明:在幼果发育阶段、中果发育阶段(包含中果期Ⅰ、中果期Ⅱ和中果期Ⅲ)和熟果发育阶段(包含熟果期Ⅰ、熟果期Ⅱ和熟果期Ⅲ),明党参果实横切面的大小和形状、果壁(包括外果壁、中果壁和内果壁)厚度及其细胞形态和层数、合生面结构、胚乳形状及大小、外胚乳存在与否、珠心退化与否以及维管束形态等特征均有明显的变化.在整个发育过程中,明党参分生果横切面的形状由近五边状圆形变化至肾状圆形;果壁由厚变薄且细胞层数逐渐减少;胚乳逐渐增大,从半圆形变化为新月形、马蹄形直至“C”形;外胚乳逐渐消失,珠心逐渐退化;合生面的细胞离层越来越明显直至完全分离.此外,明党参果实中油管和维管束数量变化较小,油管可分为维管束伴生油管和果壁油管;合生面有果壁油管4~6个,此特征与明党参属(Changium Wolff)的相关描述不一致.  相似文献   

7.
目的:研究白芷(Angelica dahurica)果实的内部结构及种子中胚乳储存物的性质。方法:常规石蜡切片技术和徒手切片法及植物组织化学方法。结果:观察到白芷果实的主要形态特征、内部结构及胚乳储藏物的特征。结论:杭白芷果实被4-5层果皮包被,果皮最外方是1层薄壁组织细胞,内方为2-3层厚壁组织细胞。种皮是一层细胞构成,胚乳占据了种子的绝大部分体积,胚乳所含有蛋白质和脂肪。  相似文献   

8.
为揭示毛竹(Phyllostachys edulis)种子生长过程中胚、胚乳、果皮及种皮的发育规律,以桂林海洋山一带的开花毛竹为材料,采集并固定不同时期的开花毛竹种子,使用石蜡制片法制片,显微镜观察胚、胚乳、果皮与种皮的结构变化。结果表明:(1)毛竹花后1 d完成受精并形成合子,合子休眠时长约为5 d。经过原胚阶段、胚芽鞘阶段、幼胚生长阶段及成熟胚阶段,花后40 d的胚发育基本成熟,其发育类型为禾本型。(2)胚乳发育早于胚的发育,其发育类型为核型胚乳,历经游离核、细胞化、细胞分化及成熟4个阶段。在细胞分化阶段胚乳细胞分化形成淀粉胚乳细胞以及糊粉层细胞,淀粉胚乳细胞主要积累淀粉粒,糊粉层细胞主要积累矿质元素、脂类及蛋白质等。(3)花后1 d的果皮细胞及珠被细胞形状规则、内含物丰富、结构完整;花后10~20 d,内、外果皮及珠被细胞层数递减,形状发生改变,中果皮细胞开始出现淀粉粒;花后20~60 d,随着胚乳细胞营养物质的积累及体积的增大,向外产生机械压力,中果皮细胞逐步消解仅剩残留的细胞壁;外果皮细胞呈长条形,细胞壁加厚,与残留的中果皮细胞壁组成保护结构;皮层在种子发育过程中主要起到合成...  相似文献   

9.
姜目姜群植物的种子解剖学和组织化学及其系统学意义   总被引:3,自引:0,他引:3  
研究了姜群4科代表植物的种子解剖学和组织化学,结果表明,姜科、闭鞘姜科和竹芋科均具假种皮。姜科的外种皮由1层细胞壁增厚的表皮细胞构成,中种皮分化为下皮层、半透明细胞层和色素层,内种皮由石细胞构成;闭鞘姜科外种皮由薄壁细胞构成,中种皮为薄壁细胞层,内种皮由石细胞构成;美人蕉科外种皮则由径向延长的Malpighian细胞构成,中种皮包含4~5层石细胞和2~5层薄壁细胞,内种皮则由色素细胞组成;竹芋科外种皮和中种皮均由薄壁细胞构成,内种皮由1层垂周壁和内平周壁极其增厚的石细胞构成。姜群中只有美人蕉科不具假种皮和孔盖,姜科和闭鞘姜科的合点区均有色素细胞群,闭鞘姜科的合点区还分化出一个内方有缺口的合点室。姜科和闭鞘姜科都有明显的内胚乳和外胚乳;美人蕉科具发达的外胚乳,内胚乳仅为一薄层;竹芋科种子不具内胚乳。综合芭蕉群种子解剖学和组织化学的研究结果,讨论了姜群4科之间的系统学关系。  相似文献   

10.
兰花蕉种子的解剖学和组织化学研究   总被引:3,自引:0,他引:3  
温颖群  廖景平  吴七根   《广西植物》1997,(3):235-241
兰花蕉种子球形或近球形,具表皮毛,种脊不明显。种子包括假种皮、种皮、外胚乳、内胚乳和胚五部分。假种皮具3~4条粗毛状裂片,包围种子或不定向伸展;裂片最外方为1层表皮细胞和1~3层厚壁细胞,内方为薄壁细胞;表皮细胞和厚壁细胞的壁增厚并木质化;成熟时裂片下部1/2段中空。种皮由外珠被发育而来,但内珠被在种子发育后期才萎缩。种皮分化为外种皮,中种皮与内种皮;外种皮由1层表皮细胞构成,其细胞壁增厚并木质化;中种皮外方为2~3层厚壁细胞,内方由12~15层薄壁细胞构成;内种皮由1层径向延长的石细胞构成,其细胞壁网状增厚,胞腔不明显。外胚乳极不显眼,大部分只由1层切向延长的长方形细胞构成,局部为2~17层细胞;外胚乳细胞主要含许多脂类物质及少量蛋白质颗粒,不含淀粉。内胚乳占据种子很大的体积,由通常径向延长的长方形、长条形或方形薄壁细胞构成;细胞内充满淀粉粒和通常一颗亦有2至多颗菱形或方形蛋白质晶体,脂类物质极少。胚圆柱形,胚根和胚芽不明显。种子珠孔区不分化出珠孔领和孔盖,但具柄,柄的远轴端边缘大部分着生假种皮,着生假种皮一侧柄略膨大。合点区内种皮出现极宽的缺口,缺口间为整体呈弧状长条形的合点区厚壁细胞群。较粗的种脊维管?  相似文献   

11.
The development of the ovule, fruit and seed of Xyris spp. was studied to assess the embryological characteristics of potential taxonomic usefulness. All of the studied species have (1) orthotropous, bitegmic and tenuinucellate ovules, with a micropyle formed by both the endostoma and exostoma; (2) a cuticle in the ovules and seeds between the nucellus/endosperm and the inner integument and between the inner and outer integuments; (3) helobial, starchy endosperm; (4) a reduced, campanulate and undifferentiated embryo; (5) a seed coat formed by a tanniferous endotegmen, endotesta with thick‐walled cells and exotesta with thin‐walled cells; and (6) a micropylar operculum formed from inner and outer integuments. The pericarp is composed of a mesocarp with cells containing starch grains and an endocarp and exocarp formed by cells with U‐shaped thickened walls. The studied species differ in the embryo sac development, which can be of the Polygonum or Allium type, and in the pericarp, which can have larger cells in either endocarp or exocarp. The Allium‐type embryo sac development was observed only in Xyris spp. within Xyridaceae. Xyris also differs from the other genera of Xyridaceae by the presence of orthotropous ovules and a seed coat formed by endotegmen, endotesta and exotesta, in agreement with the division of the family into Xyridoideae and Abolbodoideae. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 619–628.  相似文献   

12.
绞股蓝果实的发育解剖学研究   总被引:2,自引:0,他引:2  
应用石蜡切片和扫描电镜的方法,观察了绞股蓝果实与种子的发育过程,结果表明:花后12 d左右,绞股蓝合子开始进行第一次分裂,极核分裂在花后6~7 d,核型胚乳在胚的发育中被吸收,胚的发育为茄型,外珠被呈网格状花纹。假果,表面有蜡质,果壁可明显分为3层,内侧细胞后期解体,种子倒三角形,表面瘤状突起。脱落花果的结构表现为珠被萎缩和胚发育受阻。  相似文献   

13.
铃兰的胚胎学研究   总被引:4,自引:0,他引:4  
铃兰(Convallaria majalisL.)的花药四室,药壁发育为单子叶型。腺质绒毡层发育后期出现双核至多核。小孢子四分体主要呈左右对称型,偶见四面体型。胞质分裂为连续型。二细胞型花粉。子房三室,中轴胎座。胚珠倒生,双珠被,厚珠心。珠孔由内珠被形成。胚囊发育为葱型和英地百合型。受精以后,在子房壁、珠柄和外珠被细胞中含有草酸钙针晶。胚发育类似于石竹型,但基细胞发生纵裂形成两个子细胞。核型胚乳;合点端具巨形胚乳核  相似文献   

14.
Feller  Urs 《Plant & cell physiology》1978,19(8):1489-1495
Aminopeptidase, carboxypeptidase and neutral endopeptidase activitieswere analyzed in glumes and in kernels of field-grown wheat(Triticum aestivum L.) during ear development. Kernels harvestedon two dates were subdivided into outer pericarp, cross cells,endosperm and embryo. In developing parts with a net nitrogeninflux (young glumes, embryo, endosperm) the aminopeptidaseactivity is high, but in nitrogen-mobilizing tissues (senescingglumes, Outer pericarp) this activity decreases. Carboxypeptidaseis most active in fully expanded tissues. Neutral endopeptidaseshows the highest activity in the nitrogen mobilizing partsand extremely low activity in the embryo and the endosperm. (Received July 15, 1978; )  相似文献   

15.
The growth of the fruit of two varieties of almond (Prunus dulcis(Mill.) D. A. Webb) was studid from anthesis (week 0) to maturity(week 32). The dimensions, fresh weight, moisture content, anatomyand chemical composition of the pericarp, testa, embryo, endospermand nucellus are recorded diagrarnmatically, graphically andby micrographs for one variety. Of the two ovules present atflowering only one normally developed further. By 12 weeks afterflowering the whole fruit had reached full size. The space encloscdby the pericarp was filled by nuallus until weck 10, with subsequentenlargement of both endosperm and embryo. From week 16 to week20 the embryo increased to full size with a concumnt decreasein the size of the endosperm. Sixteen weeks after flowering,the embryo began to accumulate protein and lipid, little ofwhich originated from either the nucellus or endosperm. Theembryo contained no starch or reducing sugar but up to 3% sucrosein the early stags which dtcreascd as lipid and protein increased.Starch and sucrose levels were high in the testa at week 16but subsbquently dropped, starch more rapidly than sucrose.The role of the testa in transport of metabolites to the embryois discussed. Prunus dulcis, almond, fruit development, anatomy, embryo, endosperm  相似文献   

16.
The structure of embryo sac, fertilization and development of embryo and endosperm in Vigina sesquipedalis (L.) Fruwirth were investigated. Pollization occures 7–10h before anthesis, and fertilization is completed 10 h after anthesis. After fertilization, wall ingrowths are formed at the micropylar and chalazal ends of the embryo sac. Embryo development conforms to the Onagrad type, and passes through 2 or more celled proembryo, long stick-shaped, globular, heart shaped, torpedo, young embryo, growing and enlarging embryo and mature embryo. Wall ingrowths are formed on the walls of basal cells and outer walls of the cells at basal region of suspenser. The suspensor remains as the seed reaches maturity. The starch grains accumulate in the cells of cotyledons by 9–16 days after anthesis, and proteins accumulate by 12–18 days after. The endosperm development follows the nuclear type. The endosperm ceils form at the micropylar end, and remain free nuclear phase at chalazal end. The outer cells are transfer cells. Those cells at the micropylar end form folded cells with wall ingrowths. At heartembryo stage, the endosperm begins to degenerate and disintegrates before the embryo matures.  相似文献   

17.
The ovule is anatropous and bitegmic. The nuceIlar cells have disorganized except the chalazal proliferating tissue. The curved embryo sac comprises an egg apparatus and a central cell with two palar nuclei and wall ingrowths on its micropylar lateral wall. The antipodal cells disappear. Embryo development is of the Onagrad type. The filament suspensor grows to a length of 785 μm and degenerats at tarpedo embryo stage. The basal cell produces wall ingrowths on the micropylar end wall and lateral wall. The cells of mature embryo contain many globular protein bodies, 2.5–7.5 μm in diameter, composed of high concentration of protein and phytin, insoluble polysaccharide and lipid. The cells, except procambium, also contain many small starch grains. Some secretory cavities scattered in the ground tissue have liquidlike granules composed of protein, ploysacchaide and lipid. Endosperm development follows the nuclear pattern. At the late heart embryo stage, the endosperm around the embryo and the upper suspensor and the peripheral endosperm of the basal region of the U-shaped embryo sac becomes cellular. The endosperm at micropylar and chalazal ends remains free nuclear phase until the late bended cotyledon stage. Wall ingrowths at both micropylar and chalazal end wall and lateral wall of the embryo sac become more massive during endosperm development. Wall ingrowths also occur on the outer walls of the outer layer endosperm cells at both ends and lateral region of the embryo sac. When the embryo matures, many layers of chalazal endosperm ceils including 2–4 layers of transfer cells, a few of micropylar endosperm cells and 1–5 layers of peripheral endosperm cells are present. The nutrients of the embryo and endosperm at different stages of development are also discussed.  相似文献   

18.
Fruits of two varieties of Valeriana officinalis s. str. (var. officinalis , var. nitida ) are similar in general construction, but differ in details of external and internal structure. The outer cells of the pericarp form a regularly punctuated surface in both taxa. Scanning electron microscopy demonstrates variation in cuticular sculpturing of the outer epidermal cell walls and the presence of epicuticular wax. The surface of fruit hairs varies from micropapillate in var. officinalis to linear warty in var. nitida . In the mature rericarp there occur three distinct histological zones: an outer exocarp, a central mesocarp, and an inner endocarp. The seed is small, enclosed in the indehiscent fruit, with thin seed coat and a straight embryo. Endosperm is absent. The results of this carpological study, especially the SEM characters of pericarp surface, may provide criteria useful for delimitation of V officinalis varieties.  相似文献   

19.
This paper presents detailed report on the process of fertilization and the develop- ment of embryo and endosperm of Basella rubra L. The results obtained are summarized as follows: About 4–6 hours after anthesis a great deal pollen grains germinated on the stig- ma; 6–11 hours, the pollen tube passed through the style; 11–16 hours, the pollen tube reached the ovary cavity. About 16–18 hours, one sperm nucleus entered into the egg and the other one entered into the secondary nucleus. In most cases, after 16–24 hours the double fertilization had completed. After 2–8 days, two-celled proembryo was first shown. Finally, the proembryo gave rise to multicellular globular embryo proper. The development of the embryo of Basella rubra L. conforms to the Asterad type. Whether the Asterad type had a high frequency needs further to be studied. Although the fertilization of the sperm nucleus with the secondary nucleus began later, the fusion of two sexual nuclei and the development of the endosperm proceeded often quickly. After 20 hours, the free nuclei period began, and after 2–4 days the free nuclei of endosperm were rapidly formed. The endosperm of Basella rubra L. is a nuclear type. And at the time When the seed had ripened the endosperm tissues were all absorbed by the developing embryo. The author observed that there are different distributions of the vegetative nucleus and two sperms in the pollen tube, and that two sperms entered a egg or secondary nucleus. The changes of the starch accumulated and distributed et al. in the floral organs are also studied and discussed.  相似文献   

20.

Palm fruits show great structural complexity, and in-depth studies of their development are still scarce. This work aimed to define the developmental stages of the fruit of the neotropical palm Butia capitata and to characterize the ontogenesis of its pericarp. Biometric, anatomical, and histochemical evaluations were performed on pistillate flowers and developing fruits. The whole fruit develops in three phases: (I) histogenesis (up to 42 days after anthesis – DAA), when the topographic regions of the pericarp are defined; (II) pyrene maturation (42 to 70 DAA), when the sclerified zone of the pericarp is established; and (III) mesocarp maturation (70 to 84 DAA), when reserve deposition is completed. During pericarp ontogenesis (i) the outer epidermis and the outer mesophyll of the ovary give origin to the exocarp (secretory epidermis, collenchyma, parenchyma, sclerenchyma, and vascular bundles); (ii) the median ovarian mesophyll develops into the mesocarp, with two distinct topographical regions; (iii) the inner ovarian epidermis originates the endocarp; and in the micropylar region, it differentiates into the germination pore plate, a structure that protects the embryo and controls germination. (iv) Most of the inner region of the mesocarp fuses with the endocarp and, both lignified, give rise to the stony pyrene; (v) in the other regions of the mesocarp, carbohydrates and lipids are accumulated in a parenchyma permeated with fiber and vascular bundles. The development of the B. capitata pericarp presents high complexity and a pattern not yet reported for Arecaceae, which supports the adoption of the Butia-type pyrenarium fruit class.

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