长豇豆胚和胚乳的发育及营养物质积累

长豇豆(Vigna sesquipedalis (L.)Fruwirth)开花前7—10小时传粉,开花后8—10小时完成双受精。合子期珠孔端及合点部位胚囊的周界壁有壁内突。胚发育属柳叶菜型。胚柄的基部细胞及基部区域外层细胞的外切向壁发生壁内突。成熟胚中胚柄宿存。开花后9—16天为子叶细胞中淀粉积累期,开花后12—18天为蛋白质积累期。胚乳发育为核型,珠孔端胚乳细胞化,合点端保持游离核状态。胚乳外层细胞为传递型细胞,珠孔端的胚乳细胞形成折叠细胞群,亦有壁内突。心形胚期胚乳开始退化解体,成熟胚期胚乳完全消失。     

西瓜胚乳吸器的发育及ATP酶的超微细胞化学定位

报道了西瓜（Citrullus lanatus)胚乳吸器发育过程,并对胚乳吸器细胞中的ATP酶进行了超微细胞化学定位,球形胚早期,胚囊合点端的壁伸长发育成一管状胚乳吸器,进而吸器靠近乳本体端膨大为囊状,球形胚晚期吸器自珠孔端向合点端逐渐细胞化,胚分化出子叶时,胚乳吸器自合点端向珠孔端退化,在刚形成的胚乳吸器细胞中,ATP酶活性反应主要分布在细胞的核膜,内质网上,胞间连丝和吸器细胞壁内的小球状物上也有较强的ATP酶活性反应;在开始退化的吸器细胞中,核膜上的ATP酶性的反应减弱较早,内质网稍晚,进一步退化的胚乳吸器细胞中,ATP酶主要集中分布在细胞壁,细胞间隙内,核上几乎没有ATP酶性反应,内质网上仅有微弱的ATP酶反应。     

何首乌胚和胚乳的发育

何首乌为直生胚珠,双珠被。胚发育属于柳叶菜型。心形胚柄最为发达,鱼雷形胚期胚柄奶化。早期胚胎发育营养的主要来源可能是合了中积累的淀粉和胚柄吸收来的营养。成熟胚中积累了大量的蛋白质和淀粉粒。胚乳发育属核型。从球形胚期起,胚乳细胞化过程由珠孔端向合点端逐渐推进。初始垂周壁源于姊妹核间的细胞反或非姊妹核间由次生成膜生的细胞板。初始平周壁源于有丝分裂所产生的细胞板。心形胚期,除合点端保持游离核胚乳吸器外,     

大葱胚和胚乳的发育

观察了“章丘大葱”胚珠、胚囊的结构,胚及胚乳的发育。胚发育属紫菀型,经历球胚前的原胚、球胚、椭形胚、凹形胚、长棒形胚及弯形成熟胚等各期。宿存助细胞生存到球形胚期。胚乳发育属核型。球胚晚期,在胚褒珠孔端及合点端,胚乳开始细胞化。由于游离核之间出现了垂周壁,由一层胚乳游离核形成了一层无内切向壁的“开放细胞”。“开放细胞”行平周分裂而形成两层细胞,外层为完整细胞,内层为新的“开放细胞”。如此多次分裂,向心增生胚乳细胞,最后将中央细胞填满。初始的垂周壁来自于间期游离核之间的细胞板,非“自由生长壁”但又未见明显的成膜体。初始的平周壁是正常有丝分裂的胞质分裂的结果,与成膜体,细胞板有关。在球胚晚期,胚乳细胞化后,在中央液泡内观察到游离细胞。     

罗汉果胚、胚乳及胚乳吸器的发育

本文采用石蜡切片与酶解分离法对罗汉果Ｓｉｒａｉｔｉａｇｒｏｓｖｅｎｏｒｉ胚、胚乳及胚乳吸器的发育过程进行观察．ａ）罗汉果胚的发育是按Ｇｅｕｍｕｒｂａｎｕｍ的分裂程序进行的．属紫菀型．但在合子分裂成球胚过程中,胚芽原细胞分化明显．故属紫菀型的变异型。ｂ）胚乳发育属核型．在球形胚阶段,在合点端和珠孔端有发育的胚乳吸器形成并进行旺盛生长,最大长度达１４２０μｍ,心形胚期．吸器活动开始减退,合点端核型胚乳吸器转变成细胞型．由胚乳本体基部膨大细胞．充当补助吸器．ｃ）酶解分离法研究胚乳吸器的发生发育有较好的应用前景。     

大豆的胚胎学研究 Ⅰ.胚与胚乳的发育

本文报告大豆(品种为“丰地黄”)胚和胚乳发育的过程。大豆胚的发育基本上属十字花型(柳叶菜型)。因为合子首先进行横分裂,结果形成由顶细胞和基细胞构成的二细胞胚。顶细胞首先进行纵裂,成为胚体细胞的基础,基细胞发育成胚柄,而不参加胚体的形成。大豆胚柄由多列细胞組成,而十字花型(柳叶菜型)的典型代表 Capsella bursa-pastoris 和 Ludwigia palustris 的胚柄由一列细胞构成,因此与它们有明显区别。在由基细胞发育成由多列细胞粗成的胚柄过程中,观察到细胞的液泡化和后来液泡消失的过程。大豆传粉后两昼夜可见合子分裂形成二细胞胚。传粉后三天发育成3—8个细胞的胚。传粉后五天形成约由30—40个细胞组成的小圆球胚。传粉后八天发育成由更多细胞组成的大圆球胚。到传粉后十二天可以看到顶端扁平的胚,以及子叶、胚根和胚轴的分化。大豆胚乳的发育属核型。由受精的极核分裂成游离胚乳核,游离核以有丝分裂方式繁殖。它的最初几次有丝分裂是同时进行的,分裂速度与胚细胞分裂速度大体上相同。在胚乳发育过程中我们未见到无丝分裂现象,但尚不能断定在大豆胚乳发育过程中没有无丝分裂过程,因为我们固定材料时间间隔较长。在较大圆球胚时胚乳开始形成细胞壁,细胞壁的形成过程自胚端开始,逐渐及于合点端。在子叶分化时胚乳细胞壁开始破坏,其过程也是自胚端(珠孔端)开始,逐渐及于合点端。在胚乳细胞退化时看到有巨大核和比正常胚乳核小的、梭形退化的胚乳核。     

罗汉果胚,胚乳及胚乳有器的发育

本文采用石蜡切片与酶解分离法对罗汉果Ｓｉｒａｉｔｉａ ｇｒｏｓｖｅｎｏｒｉ胚、胚乳及胚乳吸器发育过程进行观察。ａ）罗汉果胚的发育是按Ｇｅｕｍ ｕｒｂａｎｕｍ的分裂程序进行的,属紫菀型。但在合子分裂成球胚过程中,胚芽原细胞分化明显,故属紫菀型的变异型。ｂ）胚乳发育属核型,在球形胚阶段,在合点端和珠孔端有发育的胚乳吸器形成并进行旺盛生长,最大长度达１４２０μｍ,心形胚期,吸器活动开始减退,合点端核型胚     

西瓜胚乳衰退过程中的超微结构变化及其对胚发育的作用

西瓜胚乳细胞衰退过程中 ,质膜、液泡膜突起、形成体积较大的囊泡 ,内质网断裂形成体积较小的囊泡 ;细胞质和细胞核降解形成电子致密的碎片沿细胞壁分布 ;细胞壁在衰退过程逐渐变薄 ,由于部分区域分解而使整个壁呈波浪型 ,细胞降解后的物质可直接穿越薄壁处或通过宽约 5 0 nm的胞间连丝向近胚端的胚乳细胞转移。胚乳与珠心组织分界壁 -胚囊壁上有发达的壁内突 ,有利于珠心组织内的物质向胚乳内转运 ;胚乳发育早期与胚共有的壁上内外两侧均有胼胝质沉积 ,壁上无外连丝型的胞间连丝存在 ,胚乳发育后期共有壁上的胼胝质消失 ,胚乳细胞降解物可穿越共有壁进入胚细胞内。实验结果表明西瓜胚乳在发育后期对胚的发育具有重要的作用。     

芍药胚和胚乳早期发育的研究

本文报道芍药(Paeonia lactiflora)的胚和胚乳的早期发育,主要结论是:1,开花后4—20天,合子核反复分裂形成多核原胚。2.原胚及胚乳游离核分裂均以有丝分裂为主,晚期有无丝分裂和多倍体核;3,细胞壁形成可由纺锤丝间和自由壁两种方式进行。原胚壁形成由合点端向珠孔端进行,胚乳则由胚附近向合点端发展。我们支持 Cave 等基于多核原胚提出的 Paeonia 与裸子植物平行演化的意见,同时认为 Paeonia 的多核原胚演化趋势是原胚由珠孔端至合点端功能分区的特化。     

短柄五加胚和胚乳发育的研究

短柄五加胚发育属茄型,棒形胚后期胚柄最为发达,球形胚胚柄开始退化,心形胚期胚柄解体。胚乳发育属核型,当胚乳游离核为２００￣３００个时,以自由生长细胞壁的方式进行胚乳细胞化。胚乳细胞进一步增殖以有丝分裂方式进行,球形胚时,胚乳细胞最外层细胞特化为分泌层,胚乳细胞贮藏蛋白质和脂类物质。在胚乳游离核为３２￣６４个时,单珠被的内表皮层分化为珠被绒毡层。合子分裂后,珠被绒毡层发育最为充分;棒形胚后期,珠被绒     

Embryo and Endosperm Development in Isatis Tinctoria L. and the Histochemical Study of Its Storage Reserve

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.     

Development of megagametophyte, embryo, and seed in Senna corymbosa (Lam.) H.S. Irwin & Barneby (Leguminosae – Caesalpinioideae)

The main aspects of seed ontogeny in Senna corymbosa were studied by standard anatomical microtechniques for light microscope observations. The results revealed an ana-campylotropous, bitegmic, and crassinucelate mature ovule. A single archesporocyte developed by an archesporial cell enlargement from the subhypodermal multicellular archesporium. Meiosis originated linear or T-shaped megasporic tetrads. The functional megaspore was the chalazal one. Megagametophytic development conformed to the Polygonum type. Fertilization was porogamic. Endosperm development was free nuclear and conformed to a chalazal haustorium. Cellular endosperm was initiated from the micropylar end during the globular embryo stage. Embryogeny derived from a linear proembryonal tetrad. The mature embryo showed an oblique axis. The testa derived from the outer ovular integument. Nucellar and endosperm remnants, and the micropylar region of the inner ovular integument, persisted at embryo maturity. The absence of a pleurogram would be adaptative to wetland habitats. The taxonomic use of the mature embryo axis in the Cassieae and the phylogenetic employment of megasporic arrangements in Leguminosae needs some reinterpretation.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 169–179.     

掌叶大黄胚胎学研究

掌叶大黄(Rheum palmatum L.)的花药4室,单或复孢原。药壁发育为单子叶型。腺质绒毡层发育后期出现双核。小孢子四分体为四面体型,胞质分裂为同时型。成熟花粉为3细胞,表面具3条沟。子房1室,单胚珠,直生,两层珠被,由内珠被形成珠孔,厚珠心。单孢原,位于珠心表皮下。直线形或T形大孢子四分体。合点端的大孢子发育为蓼型胚囊。2个极核在受精前合并为次生核。3个反足细胞宿存。胚乳发育为核型,在球形胚末期开始形成细胞。合点端的胚乳核一直不形成细胞,而为游离核的胚乳吸器。在胚乳吸器和其它部位都发现胚乳核融合现象。胚的发育属于紫菀型。胚具小胚柄。成熟胚囊时期出现承珠盘,且存留时间很长,成熟胚期尚存痕迹。     

Development of Embryo and Endosperm and Nutrient Accumulation in Vigna sesquipedalis (L.) Fruwirth

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.     

Accumulation of Metabolites during Seed Development in Trifolium repens L.

Metabolite deposition during seed development was examined histochemicallyin Trifolium repens by light- and fluorescence microscopy. Allendosperm haustorium at the chalazal pole of the embryo sacand wall protrusions in cell walls of the suspensor and theembryo sac suggest that transfer of metabolites from maternalto offspring tissue takes place primarily at these sites. Thisis further supported by prominent cutinization of the interpolarregion of the embryo sac wall, accumulation of starch in integumentaltissue at the embryo sac poles, and breakdown of interpolarendothelial cells. Decomposition of osteosclereid starch isfollowed by accumulation in the cellular endosperm and subsequentlyin the embryo parallel to endosperm degradation. The starchaccumulates gradually inward from the subepidermal cells ofthe embryo to the stele. Protein bodies are formed in the vacuolesalong the tonoplast, later to be cut off in vesicles releasedinto the cytoplasm. At maturity the embryo is packed with proteinand starch, but without lipid reserves. Phytin is observed inthe protein bodies. The mature embryo is surrounded by a proteinand starch containing aleurone layer which originates from theendosperm.Copyright 1994, 1999 Academic Press White clover, protein, starch, cuticle, embryo sac wall     

Early Endosperm Development in Ovules of Soybean, Glycine max (L) Merr. (Fabaceae)

Endosperm development was studied in normally setting flowersand pods of soybean from anthesis to a pod length of 10–20mm. The free-nuclear stage following double fertilization istypified by loss of starch and increasing vacuolation. The cytoplasmprovides evidence of extensive metabolic activity. Wall ingrowths,already present at the micropylar end of the embryo sac wallprior to fertilization, develop along the lateral wall of thecentral cell as well as at the chalazal endosperm haustorium.Endosperm cellularization begins when the embryo has developeda distinct globular embryo proper and suspensor. Cellularizationstarts at the micropylar end of the embryo sac as a series ofantidinal walls projecting into the endosperm cytoplasm fromthe wall of the central cell. The free, growing ends of thesewalls are associated with vesicles, microtubules, and endoplasrnicreticulum. Pendinal walls that complete the compartmentalizalionof portions of the endosperm cytoplasm are initiated as cellplates formed during continued mitosis of the endosperm nuclei.Endosperm cell walls are traversed by plasmodesmata. This studywill provide a basis for comparison with endosperin from soybeanflowers programmed to abscise. Glycine max, soybean, endosperm, ovules     

The Development of Green Onion (Allium Fistulosum L. )Embryo and Endosperm

Embryo development of Zhangqiu green onion conforms to the Asterad type and goes through the following stages: proembryo, globular, ellipsoidal, laterally concave, stick-shaped, and curved and mature. The persistent synergid is present until the late globular stage of embryogenesis. Endosperm development of Zhangqiu green onion follows the nuclear pattern. Endosperm cell formation begins at both the micropylar end and the chalazai end of the embryo sac when the embryo is in the late globular stage. Due to the anticlinal wall formation, a layer of free nuclei becomes a layer of “open cells” which lack the inner periclinat wall. The open cells undergo cell division periclinally, and a layer of complete cells is cut off outside and a new layer of open cells inside. The subsequent cell divisions give rise to the endosperm cells centripetally until those from the opposite of the embryo sac meet. The first anticlinal walls arise from the cell plates without phragmoplasts between the free nuclei in interphase. The first periclinal walls are formed by normal cytokinesis. When a few layers of endosperm cells are formed at the micropylar end and the chalazal end of the embryo sac, free cells are present in the central vacuole.     

中国特有河口异叶苣苔（苦苣苔科）胚胎学研究

对河口异叶苣苔的胚胎学观察旨在为该属的系统学研究提供参考。该种的花药药壁由表皮、药室内壁、中岐和绒层４层细胞组成。２－３－核细胞在绒毡层频繁出现。胚珠属倒生,单珠被和薄珠心。胚囊发育属蓼型。该种胚囊发中的双大孢子母细胞现象,分别为并列和前后排列型。前者发育至双并列四分体,后者发育到呈棱形的４个大孢子。胚乳的发育属细胞型。并在合点端和珠也端分别具有吸器。珠孔吸器发育早期为单核、２－细胞、后期为两核、２－细胞或单核、４－细胞,有时为多细胞,并在发育过程中向外伸长形成外珠孔。合点吸器为两核。由于合点吸器和珠孔吸器的活动,位于珠被最外层细胞的珠和被绒毡层之间的２－３层细胞逐渐解体和被吸收,胚的发生和发育属柳叶菜型,在胚的发育过程中,胚乳几乎被吸收耗尽,仅利下一层胚乳细胞紧贴内种皮,成熟种子的种皮由珠被最外层细胞和珠被绒毡层发育而来,本文对河口异叶苣苔的胚胎发育过程员苦苣苔科其它类群进行了广泛的比较和讨论。     

獐牙菜的胚胎发生

对獐牙菜大孢子发生、雌配子体形成、受精、胚及胚乳发育过程进行了研究。主要结果如下：子房2心皮,1室,4列胚珠,侧膜胎座;薄珠心,单珠被,倒弯生胚珠。大孢子母细胞减数分裂形成4个大孢子直线形排列,合点端的大孢子具功能,胚囊发育为蓼型。3个反足细胞宿存,每个细胞均多核和异常膨大,反足吸器明显,并在胚乳之外形成染色较深的类似“外胚乳”的结构。珠孔受精,受精作用属于有丝分裂前类型。胚乳发育为核型;胚胎发育为茄型。果实成熟时,种子发育至球形胚阶段。反足细胞在龙胆科一些短命植物中的宿存与分裂具有重要的生殖适应与进化意义。