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     

桔梗胚乳吸器结构研究

对桔梗（PlatycodongrandiflorusA.DC）的胚乳吸器进行了显微结构和超微结构研究,结果如下：1．胚乳的发育属细胞型。8-细胞胚乳时分化出珠孔吸器;16-细胞胚乳时分化出合点吸器。2．吸器细胞的壁存在大量壁内突,彼此交织成网状结构,浓厚的细胞质里有丰富的线粒体、内质网和高尔基体;细胞核及核仁异常增大;吸器细胞与胚乳细胞间存在大量的胞间连丝。3．珠被绒毡层与胚囊壁之间存在二层角质层,共同包围着胚囊,只在胚囊的珠孔端与合点端开口。胚乳吸器的功能是对来自孢子体的营养物质起吸收与转运作用,从而保证胚乳和胚的发育。     

新疆阿魏的胚胎学研究

采用常规石蜡制片技术,对新疆阿魏不同发育时期的花和果实进行了显微切片观察.结果表明:新疆阿魏小孢子母细胞的减数分裂为同时型,小孢子四分体为四面体型和十字交叉型,成熟花粉粒为3-细胞型.雌蕊2心皮合生成2室,中轴胎座,每子房室内产生上、下2个胚珠原基,其中,下方的原基正常发育,而上方的原基停止发育并最终解体,因此,每室仅产生一枚发育正常的倒生胚珠,单珠被,薄珠心,胚囊发育为蓼型;珠被绒毡层和珠孔塞发生于大孢子四分体时期,并于四核胚囊时分化完全,八核胚囊时珠被绒毡层细胞径向延长;3个成熟的反足细胞具双核.胚乳发育为核型,细胞壁较厚,细胞排列紧密,可保护胚免受机械损伤及防止胚失水.胚乳细胞中含有大量PAS染色呈正反应的物质,一些胚乳细胞异常生长形成细胞体积大、核及核仁均较大的巨形细胞.胚胎发生为茄型,四细胞原胚为直线形,十六细胞原胚的顶部由2排各4个细胞组成.成熟种子具胚乳.     

刺五加胚和胚乳发育的研究

刺五加Eleutherococcus senticosus(Rupr .et Maxim．)Maxim的胚胎发生类型为茄型。其卵细胞受精后,合子经历15天左右的休眠期才进行第一次分裂。合子分裂通常发生在胚乳细胞化之后,经棒形胚、球形胚、至果实成熟时发育到心形胚。棒形胚后期至心形胚初期,胚柄最为发达。刺五加的胚乳发育类型为核型。其初生胚乳核的休眠期为1天左右。当胚乳游离核数目增加到200至300时,胚乳以自由生长细胞壁的方式细胞化,胚乳细胞以典型的有丝分裂方式进一步增殖,增加细胞数目。球形胚时期,胚乳细胞内开始贮藏营养物质。少数种子的胚乳里存在巨大细胞核的异型胚乳细胞。在胚乳游离核为32至64个时,分化出珠被绒毡层;球形胚时期,珠被绒毡层解体。珠被绒毡层解体后,胚乳表层细胞分化为分泌层。球形胚至心形胚阶段,约有5％的种子里,胚与胚乳组织发生弥散样降解。成熟果实中,含有大量的瘪粒种子和虫咬种子;饱满种子率为40％左右。饱满种子中,胚乳组织占据种子体积的绝大部分,胚所占比率很小。讨论了不同发育时期胚和胚乳的营养供应。     

从胚胎学特征探讨四合木的系统位置

本文从胚胎学特征探讨了四合木的系统位置。胚胎学研究表明,四合木与蒺藜利具较近亲缘关系,但又有明显区别。表现为。四合木花药壁发育为基本型,绒毡层细胞多数具单核,心皮合生但深裂至近基部,胚株直生,具较长珠柄,无承珠盘,无珠被绒毡层,只具一列线形大孢子四分体,成熟胚囊为四细胞(四核),珠被在胚胎发育过程逐渐退化,因此,成熟种子中只具外珠被内层残迹;胚乳大部分细胞解体,而外缘胚乳细胞特化,在成熟种子中代替种皮起保护功能。因此,四合木是否应从蒺藜科分出而另列一种,值得进一步研究。     

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。     

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。     

Fuerte和Hass品种油梨的花粉管生长、受精与早期胚和胚乳发育的光学显微镜研究

用光学显微镜对Fuerte和Hass品种油梨的花粉管生长、受精与早期胚和胚乳发育进行了研究。授粉后24小时,花粉管穿入胚珠。当花粉管到达子房时,花粉管贴着子房内壁表面生长,然后沿着珠柄,穿过内珠被形成的珠孔,在珠心顶端的乳突细胞之间生长。它经过一个助细胞进入胚囊。授粉后48小时在胚囊中可见到精核,精核与极核融合后,精卵才融合。胚乳核先分裂,接着细胞壁形成。授粉后5—6天,合子第一次分裂。Fuerte品种授粉后1—2天的胚珠中,虽然在珠被或珠心处经常看到花粉管,但是只有不到20%的胚囊有花粉管进入。在Hass品种中,有60%的胚囊有花粉管穿入。可以认定,Fuerte品种之所以低产可能与花粉管很少进入胚囊有一定的关系。     

小麦×大麦胚胎发育的研究——Ⅲ.小麦×大麦胎胚发育过程中淀粉的积累和动态

我们观察了小麦与大麦杂交胚胎发育过程中,雌蕊各个组成部分发生的淀粉积累和转移的动态。结果如下: 1.胚乳和杂种胚早期发育过程中,子房壁和胚囊中淀粉的积累和动态的趋势与其他学者所作小麦自交的情况基本相同。2.当胚乳细胞充满胚囊而胚没有分化时,子房壁中的淀粉已极少,当胚乳解体时,子房壁中淀粉已几乎消失。可见,子房壁中淀粉的迅速消失与胚乳的迅速败育是平行的。3.胚囊发育的停滞与败育跟子房壁组织中淀粉的积累及对胚囊营养的正常供应有密切关系。4.花柱、珠被、珠心组织及胚囊中的助细胞和反足细胞,在整个杂种胚和胚乳发育过程中,始终不存在淀粉粒。助细胞胚亦和助细胞一样,无淀粉粒的存在。     

小麦×大麦胚胎发育的研究——Ⅲ.小麦×大麦胎胚发育过程中淀粉的积累和动态

我们观察了小麦与大麦杂交胚胎发育过程中,雌蕊各个组成部分发生的淀粉积累和转移的动态。结果如下: 1.胚乳和杂种胚早期发育过程中,子房壁和胚囊中淀粉的积累和动态的趋势与其他学者所作小麦自交的情况基本相同。2.当胚乳细胞充满胚囊而胚没有分化时,子房壁中的淀粉已极少,当胚乳解体时,子房壁中淀粉已几乎消失。可见,子房壁中淀粉的迅速消失与胚乳的迅速败育是平行的。3.胚囊发育的停滞与败育跟子房壁组织中淀粉的积累及对胚囊营养的正常供应有密切关系。4.花柱、珠被、珠心组织及胚囊中的助细胞和反足细胞,在整个杂种胚和胚乳发育过程中,始终不存在淀粉粒。助细胞胚亦和助细胞一样,无淀粉粒的存在。     

The Ultracytochemical Localization of ATPase Activity in the Ovules of Antirrhinum majus L.

The ultracytochemical localization of ATPase activity was carried out by the method of lead precipitation in the ovules of Antirrhinum majus L. No ATPase activity is observed in the egg apparatus, but some in the polar nuclei, cytoplasm and plasma membrane of the central cell. Between the embryo sac wall and the cuticle surrounding it, there is a gap where some filamentand vesicle-like structures were demonstrated by conventional staining method, and much of ATPase activity is found there. At the chalaza of the ovule, a lot of ATPase particles are found irt the nuclei, plasma membranes and the thick and loose wall of the hypostase cells. The particles of ATPase in the hypostase and those in the gap surrounding embryo sac are continuously distributed through the intervals of the cuticle at the chalazal end of the embryo sac. Some of ATPase particles are found on the plasma membranes and plasmadesmata of integument ceils, noticeably much more in the nucleoplasm of the integumentary tapetum. According to the ATPase distribution pattern in the ovules, we suggest that the function of the integumentary tapetum and hypostase is secretion, and that the gap surrounding the embryo sac may be an apoplastic ehannal for nutrient flow into the embryo sac.     

The Ultracytochemical Localization of ATPase Activity in the Ovules of Sunflower

The ultracytochemical localization of ATPase activity was determined employing the method of lead precipitation in the ovules of sunflower (Helianthus annuus L.). No ATPase activity is observed in the egg and synergids except some at the filiform apparatus. Much ATPase activity is localized on the plasma membrane and wall of the central cell. In the antipodal cells, ATPase activity is also found on the plasma membranes, but only a little in their walls. In the integumentary tapetum, besides the plasma membranes, most of the nuclei are rich in ATPase. Between the integumentary tapetum and uncontinuous cuticle surrounding the embryo sac, there is a gap where a lot of ATPase are found. These ATPases are continuously linked with those in the central cell wall throuth the intervals of the cuticle. At the sites of the wall ingrowths of the central celT, abundant vesicles and other structures with high ATPase activity aggregate noticeably in the gap region. According to the ATPase distribution in the ovules, we propose that the whole surface of embryo sac functions in absorbing nutrients directly from the apoplast outside the cuticle, especially via the wall-membrane apparatus of 'he central cell.     

Cytopathology of Mature Ovaries from Lettuce Plants Infected by Lettuce Mosaic Potyvirus

The location of lettuce mosaic potyvirus (LMV) in mature ovaries of lettuce plants ( Lactuca sativa ) was studied by conventional thin-section electron microscopy and immunogold cytochemistry. Flexuous filamentous particles and inclusion bodies characteristic of LMV infection were observed in the integumentary tapetum, integument and ovary wall of the mature ovary but not in the embryo sac.     

Embryo sac development in Arabidopsis thaliana II. The cytoskeleton during megagametogenesis

The microtubular and actin cytoskeletons have been investigated during megagametogenesis in Arabidopsis thaliana using immunofluorescence labelling of isolated coenocytic and mature embryo sacs. We found both actin and microtubules (MTs) to occur in abundance throughout megagametogenesis and in all constituent cells of the mature embryo sac. During many stages, the patterns of distribution of these cytoskeletal elements are congruent and may prove to be co-aligned. Many changes in the arrays of MTs and microfilaments take place and indicate varying roles of the cytoskeleton in the different stages and cell types of megagametogenesis. Two major populations of MTs recur throughout embryo sac formation: (1) Elaborate nuclear-based networks are found during the two-nucleate and four-nucleate developmental stages as well as in the egg cell. These arrays may function in positioning the nuclei. (2) Cytoplasmic MTs in longitudinal orientation in the two-nucleate embryo sac, synergids and part of the egg cell, or in a reticulate pattern in the four-nucleate embryo sac, egg and central cell probably participate in organization of the cytoplasm. Synergid MTs converge at the filiform apparatus. Preprophase bands of MTs are absent throughout megagametogenesis but phragmoplast arrays occur during cellularization of the embryo sac. Well developed arrays of cortical MTs are restricted to the antipodal cells. A large concentration of MTs in the part of the egg cell adjacent to the synergids is well placed for being involved with sperm cell movement within the degenerative synergid. On the basis of the morphology of the cytoskeleton, we concur with views that the shape of megagametophyte is largely determined by the surrounding tissues, including the integumentary tapetum.     

落葵的花粉粒和胚囊的形成与发育

落葵(Basella rubra L.)小孢子的发育为同时型,四分体呈四面体排列。在花粉母细胞减数分裂过程中,可清楚地看到胼胝壁的消长变化。三胞花粉,具散沟和网状纹饰。腺质绒毡层。 胚囊的发育为蓼型。反足细胞早期退化。内珠被突出形成珠被喙,同时,在其珠孔区域,有由内珠被的内表皮细胞所发育而来的类似盖状结构。 本文还注意到同一花中以及相邻花朵之间,花粉粒与胚囊发育进程的相关。花粉粒的发育略早于胚囊的发育,但以后由于胚囊母细胞形成胚囊的进程较为迅速,以致花粉粒与胚囊能够同时成熟。     

Embryogeny ofPhaseolus coccineus: Growth and microanatomy

Summary During early embryogeny, the development of the suspensor is rapid both in terms of size and fresh weight; structural differentiation can be observed as early as the proembryo stage with the formation of wall ingrowths. Ingrowths first appear in the outer wall of the suspensor cells adjacent to the integumentary tapetum, soon ingrowths begin to form in the inner suspensor cells as well. A basal-terminal gradation in nuclear size exists, with the largest nuclei in the basal suspensor cells. Cytologically, the suspensor cells appear to be very active, especially when the embryo reaches heart stage. Initially, the development of the embryo proper lags behind the suspensor, but its size and fresh weight increase rapidly as development proceeds. The volume of the liquid endosperm rises most rapidly during the late heart stage; and it is absorbed soon after. A cellular endospermic sheath surrounds the embryo, separating it from the liquid endosperm. Structural differentiation also occurs in the cellular endosperm cells with the formation of wall ingrowths in those cells that abut directly onto the integumentary tapetum. Both the suspensor and the cellular endosperm appear to remain active through the maturation of the seed. Storage bodies are formed in the cotyledons as well as in the embryonic axis. In the suspensor and the cellular endosperm, starch grains and lipid bodies can be found at the maturation stage.     

海桐大、小孢子发育及雌、雄配子体形成的研究

利用常规石蜡制片法研究了海桐大、小孢子发生及雌、雄配子体发育的过程。结果显示:(1)小孢子母细胞减数分裂过程中的胞质分裂为连续型,四分孢子为以四面体形为主,四分孢子后期部分小孢子壁皱缩;(2)花药壁由4层结构组成,由外到内为表皮、药室内壁、中层和绒毡层;(3)海桐具多个胚珠,单珠被,薄珠心,胚珠类型为倒生胚珠。大孢子母细胞减数分裂主要形成线形排列的4个大孢子,还具有少有的十字形排列,功能大孢子位于合点端;(4)胚囊发育属单孢型的蓼型,成熟的雌配子体为四细胞五核胚囊。     

黄顶菊的大孢子发生、雌配子体与胚胎发育

用常规石蜡制片对黄顶菊(Flaveria bidentis(L.) Kuntze)大孢子发生、雌配子体和胚胎的发育过程进行了观察.黄顶菊雌蕊柱头二裂,2心皮,1室,单胚珠,基生胎座,单珠被,薄珠心,倒生胚珠,具发达的珠被绒毡层.珠心表皮下分化出孢原细胞,孢原细胞直接发育为大孢子母细胞,大孢子母细胞减数分裂形成直列四分体...     

星星草大、小孢子发生与雌、雄配子体发育的观察

利用常规石蜡制片法研究了星星草[Puccinellia tenutiflora(Griseb．)Scribn．et Merr．]大、小孢子发生及其雌、雄配子体的发育过程。主要结论是：(1)小孢子母细胞减数分裂过程中的胞质分裂为连续型,四分孢子为左右对称型;(2)成熟的花粉为三细胞型,具单萌发孔;(3)花药壁由4层结构组成,最外层为表皮,其内分别为药室内壁、中层、绒毡层,绒毡层为分泌型,花药壁的发育属于单子叶型;(4)星星草为单子房,单胚珠,双珠被,薄珠心,倒生型胚珠。大孢子母细胞经减数分裂形成线形排列的4个大孢子,合点端大孢子具功能;(5)胚囊发育属于蓼型,成熟胚囊形成时,反足细胞经无丝分裂形成4～6个反足细胞,反足细胞内可能存在多次DNA复制过程。     

山茶科核果茶属和石笔木属的胚胎学研究

观察了短叶核果茶,石笔木,粗毛石笔木和屏石笔木的大小孢子和雌雄配子体的发生和发育过程,４个种的胚胎学特征高度相似,均为基本型药壁发育,腺质线毡层,同时型小孢子母细胞胞质分裂,四面体形小孢子四分体,二细胞成熟花粉,倒生胚珠,双珠被,薄珠心,单孢原,蓼胚囊,卵细胞与助细胞区分明显,均具有珠被绒毡层和承珠盘,以蓼型胚囊区别于邻近的山茶属。