麦冬花药绒毡层和乌氏体的细微结构

麦冬(Ophiopogon japonicus)的绒毡层发育为分泌型。在小孢子母细胞时期,绒毡层细胞达到了发育的高峰。此时,绒毡层细胞中细胞器非常丰富,具大量线粒体、高尔基体和质体,尤以肉质网含量最多;原乌氏体出现较早,在小孢子母细胞时期绒毡层细胞中就已出现;四分体时期,大量原乌氏体被排入内切向面的质膜和纤维素壁之间;到了小孢子早期,绒毡层细胞失去细胞壁,原乌氏体分布在质膜的凹陷处,孢粉素物质在其上沉积,发育为乌氏体,乌氏体有单个和复合两种类型;当花粉成熟时,绒毡层细胞完全解体。     

白皮松绒毡层细胞超微结构的研究

白皮松绒毡层细胞的细胞器是十分丰富的,其中粗糙内质网、核糖体和造粉体在减数分裂过程中达到高峰。小孢子形成时,绒毡层细胞开始解体,内质网和线粒体是最后衰老的细胞器。在单核花粉形成时,处于绒毡层细胞外切向壁上的周绒毡层膜特别明显。但是,孢粉素体却主要分布在内切向壁和径向壁上。有趣的是,绒毡层细胞中的造粉体结构与壁层细胞不同。而且,脂体在二分体阶段基本消失,相反,此刻孢粉素体却在质膜外大量聚集。推测脂体的消长可能与原乌氏体和孢粉素体的形成有关。     

地黄绒毡层二型性的超微结构研究

地黄的花药绒毡层具二型性,来源于初生壁细胞的ｐ－绒毡层,细胞较小,为分泌型绒毡层,在小孢子阶段产生乌氏体,于两细胞花粉阶段解体,来源于药隔的ｃ－绒毡层细胞较大,解体的时间早于ｐ－绒毡层,不同药室的ｃ－绒毡层解体的起始时间不一致,可始于小孢母细胞减数分裂,四分体或小孢子阶段,其径向壁面向药室的壁也较早地开始解体,细胞质碎片与细胞器流入药室,分散在小孢子之间,较早解体的ｃ－绒毡层细胞不产生原乌氏体与乌     

百合花药壁层的发育及组织化学研究

对生长在陕西留坝的百合的花药壁层发育过程,特别是绒毡层的发育做了形态学观察。其结果是：百合花药壁层的发育方式为基本型。花药绒毡层属腺质绒毡层类型。在单细胞花粉阶段后期,部分花粉粒壁一侧凹陷时,绒毡层细胞内切向面上出现乌氏体。随着发育阶段的推移,乌氏体的数量有所增加。在光学显微镜下观察：每个乌氏体只有一个乌氏体芯。在乌氏体出现时,也可观察到花粉外壁外层的出现。到二细胞花粉时,花药开裂之前,绒毡层细胞     

白头翁绒毡层和周绒毡层膜的发育和组织化学研究

白头翁绒毡层为分泌型,发育过程分为：发生－分化,生长－合成和分泌－解体3个阶段。第1阶段,绒毡层细胞的形态结构和组织化学特征同造孢组织和花粉母细胞的大体一致,所不同的是大量积累淀粉和形成少量原乌氏体,第2阶段为重要的合成时期;细胞体积膨大,具多倍体双核或畸形核,蛋白质大量合成,淀粉水解;原乌氏体和孢粉素荧光物质大量累积。第3阶段为分泌最活跃时期,裸细胞在妨行分泌功能上起着重要作用。原乌氏体,荧光物质,碳水化合物,或许包括分解胼胝质壁和纤维素壁酶等成分均在裸细胞阶段排出,周绒毡层膜,乌氏体和花粉外壁均属于孢粉素性质的结构,根据周绒毡层膜的外切向位置和结构,初步结论：它可能是绒毡层细胞质膜向着药壁中层一面的残存部分,而膜内表面上的孢粉素纹理则是后来添加的。乌氏体的基本形态为短颈烧瓶状,单个或2－5个组成复合结构,本文对绒毡层,绒毡层膜和乌氏体的功能,及孢粉素的转运和聚合等问题进行了讨论。     

白头翁绒毡层和周绒毡层膜的发育和组织化学研究

白头翁绒毡层为分泌型,发育过程分为：发生－分化,生长－合成和分泌－解体3个阶段。第1阶段,绒毡层细胞的形态结构和组织化学特征同造孢组织和花粉母细胞的大体一致,所不同的是大量积累淀粉和形成少量原乌氏体,第2阶段为重要的合成时期;细胞体积膨大,具多倍体双核或畸形核,蛋白质大量合成,淀粉水解;原乌氏体和孢粉素荧光物质大量累积。第3阶段为分泌最活跃时期,裸细胞在妨行分泌功能上起着重要作用。原乌氏体,荧光物质,碳水化合物,或许包括分解胼胝质壁和纤维素壁酶等成分均在裸细胞阶段排出,周绒毡层膜,乌氏体和花粉外壁均属于孢粉素性质的结构,根据周绒毡层膜的外切向位置和结构,初步结论：它可能是绒毡层细胞质膜向着药壁中层一面的残存部分,而膜内表面上的孢粉素纹理则是后来添加的。乌氏体的基本形态为短颈烧瓶状,单个或2－5个组成复合结构,本文对绒毡层,绒毡层膜和乌氏体的功能,及孢粉素的转运和聚合等问题进行了讨论。     

萍乡显性雄性核不育水稻超微结构研究

利用电镜技术对萍乡显性核不育水稻可育株和不育株花粉形成及发育过程和药壁组织的基本结构及其发育进行了研究。导致了其不育花粉败育的主要原因有：（1）绒毡层细胞表现为延迟解体,乌氏体不能与小孢子细胞壁的形成,特别是纯合不育株绒毡层细胞存在乌氏体的异位分布;（2）药隔维管束异常,导致营养物质运输缺乏,薄壁细胞液泡化,排列紊乱,杂合不育株薄壁细胞互相融合,出现核转移的独特现象。     

文冠果可孕花与不孕花发育过程的比较研究简

利用半薄切片和透射电镜技术对文冠果可孕花和不孕花的发育过程进行观察和比较。结果显示：(1)小孢子发育初期,两种类型花花药形态无明显差别;小孢子发育双核期,可孕花花药内壁纤维层细胞壁带状加厚,无唇细胞形成。而不孕花花药同侧两个花粉囊之间唇细胞正在分化;小孢子发育成熟期,不孕花花药唇细胞完全形成;散粉期,不孕花花药开裂呈双心形,而可孕花花药则不能开裂散粉。(2)可孕花雌蕊子房内有两室,柱头细胞排列紧密,柱头逐渐发育成圆球形,周围密布乳突细胞,具中空花柱道;不孕花雌蕊柱头停止发育,无中空花柱道,子房室变小,胚囊发育退化。(3)不孕花花药绒毡层中含大量蛋白体,小泡以及乌氏体等细胞器,发育后期绒毡层解体。而可孕花花药绒毡层中细胞器和营养物质积累均较少,发育后期绒毡层解体不完全。(4)可孕花花药内花粉粒细胞壁连续无萌发孔,细胞内含物较少。不孕花花药内花粉出现3个向内凹陷的萌发孔,且花粉内含有大量造粉质体和脂类物质。     

文冠果可孕花与不孕花发育过程的比较研究

利用半薄切片和透射电镜技术对文冠果可孕花和不孕花的发育过程进行观察和比较。结果显示:(1)小孢子发育初期,两种类型花花药形态无明显差别;小孢子发育双核期,可孕花花药内壁纤维层细胞壁带状加厚,无唇细胞形成。而不孕花花药同侧两个花粉囊之间唇细胞正在分化;小孢子发育成熟期,不孕花花药唇细胞完全形成;散粉期,不孕花花药开裂呈双心形,而可孕花花药则不能开裂散粉。(2)可孕花雌蕊子房内有两室,柱头细胞排列紧密,柱头逐渐发育成圆球形,周围密布乳突细胞,具中空花柱道;不孕花雌蕊柱头停止发育,无中空花柱道,子房室变小,胚囊发育退化。(3)不孕花花药绒毡层中含大量蛋白体,小泡以及乌氏体等细胞器,发育后期绒毡层解体。而可孕花花药绒毡层中细胞器和营养物质积累均较少,发育后期绒毡层解体不完全。(4)可孕花花药内花粉粒细胞壁连续无萌发孔,细胞内含物较少。不孕花花药内花粉出现3个向内凹陷的萌发孔,且花粉内含有大量造粉质体和脂类物质。     

羽叶薰衣草雄性不育的细胞学研究

用光镜和电镜观察羽叶薰衣草(Lavandula pinnata L.)雄性不育小孢子发育过程的细胞形态学特征.结果表明:羽叶薰衣草花药4枚,每枚花药通常具4个小孢子囊.花药壁发育为双子叶型,从外向内分为表皮、药室内壁、中层和绒毡层4层细胞.减数分裂形成的四分体为四面体及十字交叉型.小孢子的发育过程可分为造孢细胞期、减数分裂时期、小孢子发育早期、小孢子发育晚期.未观察到二胞花粉期和成熟花粉期.羽叶薰衣草花粉败育主要发生在单核花粉时期,细胞内物质解体并逐渐消失变成空壳花粉或花粉皱缩变形成为各种畸形的败育花粉.在此之前小孢子的发育正常.羽叶薰衣草小孢子不育机制体现在绒毡层过早解体、四分体时期以后各细胞中线粒体结构不正常、胼胝质壁与小孢子母细胞脱离、花药壁细胞中淀粉出现时间异常等. 壁发育为双子叶型,从外向内分为表皮、药室内壁、中层和绒毡层4层细胞.减数分裂形成的四分体为四面体及十字交叉型.小孢子的发育过程可分为造孢细胞期、减数分裂时期、小孢子发育早期、小孢子发育晚期.未观察到二胞花粉期和成熟花粉期.羽叶薰衣草花粉败育主要发生在单核花粉时期,细胞内物质解体并逐渐消失变成空壳花粉或花粉皱缩变形成为各种畸形的败育花粉.在此 前小孢子的发育正常.羽叶薰衣草小孢子不育机制体现在绒毡层过早解体、四分体时期以后各细胞中线粒体结构不正常、胼胝质壁与小孢子母细胞脱离、花药壁细胞中淀粉出现时间异常等. 壁发育为双子叶型,从外向内分为表皮、药室内壁、中层和绒毡层4层细胞.减数分裂形成的四分体为四     

洋葱花药发育中钙离子分布特征

采用焦锑酸钾沉淀钙离子技术,对洋葱（Alliumcepa）花药发育中Ca^2＋分布进行了研究。在小孢子母细胞时期,小孢子母细胞中的钙沉淀颗粒很少,但绒毡层细胞的内切向壁已出现明显的钙沉淀颗粒。在四分体时期,四分体小孢子的胼胝质壁中出现较多的钙沉淀颗粒;绒毡层细胞内切向壁的钙沉淀颗粒消失,而在外切向壁和径向壁部位的钙沉淀颗粒增加。在小孢子早期,小孢子中也出现了钙沉淀颗粒,而绒毡层细胞内切向壁表面出现了很多絮状物,其上附有细小钙沉淀颗粒。到小孢子晚期,小孢子中出现一些小液泡,细胞质中的钙沉淀颗粒有所下降。此时绒毡层细胞已明显退化,但在绒毡层膜上仍有一些乌氏体和钙沉淀颗粒。在二胞花粉早期,营养细胞中的液泡收缩、消失,细胞质中又出现了较多的钙沉淀颗粒,在质体和其内部的淀粉粒表面上附有较多的钙沉淀颗粒。到二胞花粉晚期,花粉中的钙沉淀颗粒已明显下降,仅在花粉外壁中还有一地钙沉淀颗粒．     

Fine Structure of Tapetal Cells and Ubisch Bodies in the Anther of Ophiopogon japonicus

The development of the tapetum in Ophiopogon ]aponicus is of secretory type Tapetum develops at their peak during the microspore mother cell stage. There are abundant organelles, consisting of a lot of mitochondria, dictyosomes and plastids, especially endoplasmic reticulum. Pro-Ubisch bodies e. merge as early as at the stage of microspore mother cell. At tetrad stage, a large number of pro-Ubisch bodies accumulate between inner tangential face of the plasmalemma and the cell wall. At the early microspore stage, pro-Ubisch bodies are distributed in the small embayments of the plasmalemma. As the sporopollenin begins to deposit on them, proubisch bodies develop into Ubisch bodies which consist of two types: single and aggregated. Tapetal cells degenerate completely when pollen grains reach maturity.     

华北落叶松花粉发育过程中的钙动态分布

运用焦锑酸钾沉淀法研究了华北落叶松(Larix principis-rupprechtii Mayr)小孢子发育过程中不同阶段Ca2 的分布情况.减数分裂时期,小孢子囊壁表皮和中层细胞的细胞壁及细胞间隙Ca2 分布较多,绒毡层只有外切向面的细胞膜有Ca2 分布,小孢子母细胞的各部位则很少有Ca2 ;四分体时期,包围四分小孢子的胼胝质壁上有大量的Ca2 分布,在四分孢子壁上也有较多沉淀;游离小孢子时期,钙离子在小孢子壁的分布较四分体时期有所减少,而到花粉成熟时又逐渐增多;从四分体到花粉成熟,乌氏体周围的Ca2 有增多的趋势.对四分体外壁Ca2 的大量分布与花粉壁的形成及信号物质在花粉表面贮存的关系,以及小孢子囊的外壁、绒毡层和乌氏体在Ca2 向花粉运输中所起的作用进行了讨论.     

芝麻核雄性不育系ms86-1微粉发生的细胞学观察

芝麻(Sesamum indicum)核雄性不育系ms86-1姊妹交后代表现为可育、部分不育(即微粉)及完全不育(简称不育)3种类型。不同育性类型的花药及花粉粒形态差异明显。Alexander染色实验显示微粉植株花粉粒外壁为蓝绿色, 内部为不均一洋红色, 与可育株及不育株花粉粒的染色特征均不相同。为探明芝麻微粉发生机理, 在电子显微镜下比较观察了可育、微粉、不育类型的小孢子发育过程。结果表明, 可育株小孢子母细胞减数分裂时期代谢旺盛, 胞质中出现大量脂质小球; 四分体时期绒毡层细胞开始降解, 单核小孢子时期开始出现乌氏体, 成熟花粉时期花粉囊腔内及花粉粒周围分布着大量乌氏体, 花粉粒外壁有11–13个棱状凸起, 表面存在大量基粒棒, 形成紧密的覆盖层。不育株小孢子发育异常显现于减数分裂时期, 此时胞质中无脂质小球出现, 细胞壁开始积累胼胝质; 四分体时期绒毡层细胞未见降解; 单核小孢子时期无乌氏体出现; 成熟花粉时期花粉囊腔中未发现正常的乌氏体, 存在大量空瘪的败育小孢子, 外壁积累胼胝质, 缺乏基粒棒。微粉株小孢子在减数分裂时期可见胞质内有大量脂质小球, 四分体时期部分绒毡层发生变形, 单核小孢子时期有部分绒毡层开始降解; 绒毡层细胞降解滞后为少量发育进程迟缓的小孢子提供了营养物质, 部分小孢子发育为正常花粉粒; 这些花粉粒比较饱满, 表面有少量颗粒状突起, 但未能形成覆盖层, 花粉囊腔中及小孢子周围存在少量的乌氏体。小孢子形成的育性类型与绒毡层降解是否正常有关。     

Pollen and Tapetum Development in Male Fertile Rosmarinus Officinalis L. (Lamiaceae)

The development of microspores/pollen grains and tapetum was studied in fertile Rosmarinus officinalis L. (Lamiaceae). Most parts of the cell walls of the secretory anther tapetum undergo modifications before and during meiosis: the inner tangential and radial cell walls, and often also the outer tangential and radial wall, acquire a fibrous appearance; these walls become later transformed into a thin poly-saccharidic film, which is finally dissolved after microspore mitosis. Electron opaque granules found within the fibrous/lamellated tapetal walls consist of sporopollenin-like material, but cannot be interpreted as Ubisch bodies. The middle lamella and the primary wall of the outer tangential and radial tapetal walls remain unmodified, but get covered by an electron opaque, sporopollenin-like layer. Pollenkitt is formed only by lipid droplets from the ground plasma and/or ER profiles, the plastids do not form pollenkitt precursor lipids. Tapetum maturation (“degeneration”) does not take place before late vacuolate stage.

The apertures are determined during meiosis by vesicles or membrane stacks on the surface of the plasma membrane. The procolumellae are conical, but at maturity the columellae are more cylindrical in shape. The columellar bases often fuse, but a genuine foot layer is lacking. The formation of the endexine starts with sporopollenin-accumulating white lines adjacent to the columellar bases. Later, the endexine grows more irregularly by the accumulation of sporopollenin globules. In mature pollen the intine is clearly bilayered.

Generative cells (GCs) and sperm cells contain a comparatively large amount of cytoplasm, and organelles like mitochondria, dictyosomes, ER, and multi-vesicular bodies, but no plastids; GCs and sperms are separated from the vegetative cell only by two plasma membranes.     

Microsporogenesis and exine structure in Trochodendron aralioides Siebold and Zuccarini (Trochodendraceae)

This study aimed to elucidate the anther wall development, pollen wall development, and exine structure of Trochodendron aralioides Siebold and Zuccarini, a tree with primitive vessels but long considered to lack vessel elements in its wood. The anther wall is the basic type: epidermis, endothecium layer, three middle layers, and tapetum. The anther tapetum is glandular and cells are uniseriate. Microspore mother cells undergo meiosis with simultaneous cytokinesis to produce tetrahedral tetrads enclosed within a callose wall. Before development of the protectum, primexine is inserted against the callose, and the plasma membrane is invaginated. Then, the probacula are elongated under the protectum and arise basally from the plasma membrane. The foot layer formation is concomitant with callose wall dissolution. The foot layer is thick, and the endexine is thin. The foot layer and the endexine are both continuous. The intine is initially formed in the vacuolated microspore stage. Hollow Ubisch bodies are observed on the inner surface of the tapetum in free microspore stage. Pollen grains are tricolporate and 2-celled at the time of shedding. The numerous anthers of a single flower are at different development stages in both protandrous and protogynous individuals.     

Development of the pollen grain and tapetum of wheat (Triticum aestivum) in untreated plants and plants treated with chemical hybridizing agent RH0007

Summary A study of pollen development in wheat was made using transmission electron microscopy (TEM). Microspores contain undifferentiated plastids and mitochondria that are dividing. Vacuolation occurs, probably due to the coalescence of small vacuoles budded off the endoplasmic reticulum (ER). As the pollen grain is formed and matures, the ER becomes distended with deposits of granular storage material. Mitochondria proliferate and become filled with cristae. Similarly, plastids divide and accumulate starch. The exine wall is deposited at a rapid rate throughout development, and the precursors appear to be synthesized in the tapetum. Tapetal cells become binucleate during the meiosis stage, and Ubisch bodies form on the plasma membrane surface that faces the locule. Tapetal plastids become surrounded by an electron-translucent halo. Rough ER is associated with the halo around the plastids and with the plasma membrane. We hypothesize that the sporopollenin precursors for both the Ubisch bodies and exine pollen wall are synthesized in the tapetal plastids and are transported to the tapetal cell surface via the ER. The microspore plastids appear to be involved in activities other than precursor synthesis: plastid proliferation in young microspores, and starch synthesis later in development. Plants treated with the chemical hybridizing agent RH0007 show a pattern of development similar to that shown by untreated control plants through the meiosis stage. In the young microspore stage the exine wall is deposited irregularly and is thinner than that of control plants. In many cases the microspores are seen to have wavy contours. With the onset of vacuolation, microspores become plasmolyzed and abort. The tapetal cells in RH0007-treated locules divide normally through the meiosis stage. Less sporopollenin is deposited in the Ubisch bodies, and the pattern is less regular than that of the control. In many cases, the tapetal cells expand into the locule. At the base of one of the locules treated with a dosage of RH0007 that causes 95% male sterility, several microspores survived and developed into pollen grains that were sterile. The conditions at the base of the locule may have reduced the osmotic stress on the microspores, allowing them to survive. Preliminary work showed that the extractable quantity of carotenoids in RHOOO7-treated anthers was slightly greater than in controls. We concluded that RH0007 appears to interfere with the polymerization of carotenoid precursors into the exine wall and Ubisch bodies, rather than interfering with the synthesis of the precursors.     

华北落叶松花粉发育过程中的钙动态分布

运用焦锑酸钾沉淀法研究了华北落叶松(Larixprincipis-rupprechtiiMayr)小孢子发育过程中不同阶段Ca2 的分布情况。减数分裂时期,小孢子囊壁表皮和中层细胞的细胞壁及细胞间隙Ca2 分布较多,绒毡层只有外切向面的细胞膜有Ca2 分布,小孢子母细胞的各部位则很少有Ca2 ;四分体时期,包围四分小孢子的胼胝质壁上有大量的Ca2 分布,在四分孢子壁上也有较多沉淀;游离小孢子时期,钙离子在小孢子壁的分布较四分体时期有所减少,而到花粉成熟时又逐渐增多;从四分体到花粉成熟,乌氏体周围的Ca2 有增多的趋势。对四分体外壁Ca2 的大量分布与花粉壁的形成及信号物质在花粉表面贮存的关系,以及小孢子囊的外壁、绒毡层和乌氏体在Ca2 向花粉运输中所起的作用进行了讨论。