南方山荷叶大、小孢子发生与雌、雄配子体发育

首次报道了南方山荷叶大、小孢子发生和雌、雄配子体形成。主要结果如下:花药4室,花药壁发育为基本型,由7层细胞组成,由外到内依次为表皮、药室内壁、3层中层和2层绒毡层;药室内壁有带状加厚现象,绒毡层细胞多具双核,为腺质型绒毡层;多孢原,发生于表皮下;小孢子母细胞减数分裂为同时型,小孢子四分体多为四面体型,少数为十字交叉形、直线形、左右对称形或"T"形;成熟花粉粒为2-细胞型,偶见3-细胞型;成熟花粉粒呈圆形,具单萌发孔。雌蕊1枚,子房单心皮,纵切面呈瓶状;1室,边缘胎座,具4～5枚发育不同步的横生胚珠。胚珠具双珠被,厚珠心;珠孔由两层珠被共同形成,在一直线上或呈"之"字形。多孢原,位于珠心表皮下。直线形四分体,合点端的1个大孢子发育为功能大孢子,胚囊发育为蓼型。成熟胚囊中,3个反足细胞大而明显,但宿存时间短,较早退化。     

柴胡大、小孢子发生及雌、雄配子体发育

以柴胡(Bupleurum chinense)为研究对象, 运用石蜡切片技术对其大、小孢子发生及雌、雄配子体发育进行了研究。结果表明: 柴胡花药具4个药室, 花药壁由表皮、药室内壁、中层和绒毡层4层细胞构成, 花药壁发育为双子叶型, 腺质绒毡层。小孢子母细胞减数分裂的胞质分裂为同时型, 产生正四面体型小孢子。成熟花粉三细胞型。胚珠倒生型, 单珠被, 薄珠心。大孢子母细胞常为一个雌性孢原直接发育而成, 大孢子四分体呈线型或T型排列, 多数情况为合点端一个大孢子分化为功能大孢子, 由功能大孢子发育为蓼型成熟胚囊。在胚囊发育过程中, 珠被内表皮细胞特化成珠被绒毡层。同一朵花中, 雄蕊先熟, 记 录了花蕾大小及雌、雄配子体发育的对应关系。     

柴胡大、小孢子发生及雌、雄配子体发育

以柴胡（Bupleurum chinense）为研究对象,运用石蜡切片技术对其大、小孢子发生及雌、雄配子体发育进行了研究。结果表明：柴胡花药具4个药室,花药壁由表皮、药室内壁、中层和绒毡层4层细胞构成,花药壁发育为双子叶型,腺质绒毡层。小孢子母细胞减数分裂的胞质分裂为同时型,产生正四面体型小孢子。成熟花粉三细胞型。胚珠倒生型,单珠被,薄珠心。大孢子母细胞常为一个雌性孢原直接发育而成,大孢子四分体呈线型或T型排列,多数情况为合点端一个大孢子分化为功能大孢子,由功能大孢子发育为蓼型成熟胚囊。在胚囊发育过程中,珠被内表皮细胞特化成珠被绒毡层。同一朵花中,雄蕊先熟,记录了花蕾大小及雌、雄配子体发育的对应关系。     

短柄五加大,小孢子发生和雌,雄配子体发育的研究

短柄五加花药５枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房５室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处     

菠萝的胚胎学研究

本文介绍对菠萝(Ananas comosus)配子体与种子发育的观察研完。菠萝的花药壁由表皮、药室内壁和两层中层组成。成熟时一中层解体,另一中层与药室内壁有纤维状加厚。成熟的绒毡层是双核的,并且是腺质型的。小孢子四分体多半为等面的。大多数胚珠倒生(3—9％是直生胚珠),双珠被,具厚珠心。胚囊的发育属蓼型,胚乳属沼生目型。胚的发育属紫莞型。成熟的胚为典型的单子叶型。种皮由内外珠被共同形成。受精后120—130天种子成熟。     

宁夏枸杞的大、小孢子发生和雌、雄配子体发育

在幼小花药横切面上,每个角隅处可见一层拱形孢原细胞,其经过平周分裂形成初生造孢细胞、次生造孢细胞,发育为小孢子母细胞。减数分裂过程中胞质分裂为同时型。四分体为四面体型。成熟花粉粒含二细胞,具三孔沟型萌发孔。花药绒毡层由二部分组成:药壁区的绒毡层由初生壁细胞所产生,药隔区的由药隔细胞直接转化成,为双重起源,呈二型性,属分泌型。雌蕊由二个心皮构成二室子房,中轴胎座。倒生胚珠具单珠被、薄珠心,珠被绒毡层。胚囊发育为蓼型。在胚囊细胞分化后,组成胚囊的四种细胞继续发育,表现出各自的形态学变化。     

中国特有属藤山柳属(猕猴桃科)的花药和胚珠发育及其分类学意义

首次报道了刚毛藤山柳（Clematoclethra scandens subsp.scandens）的花药和早期胚珠发育的胚胎学特征：花药4室;发育完整的花药壁6层,为基本型花药壁,由外至内分别为表皮、药室内壁、两层中层和两层绒毡层;腺质型绒毡层为2核或3核,纤维性加厚发生于药室内壁;小孢子母细胞减数分裂为同时型胞质分裂,小孢子四分体多为四面体型;成熟花粉粒为2-细胞型,3孔沟或稀4孔沟。早期胚珠为近倒生,单珠被,薄珠心,珠孔由单珠被构成。比较胚胎学研究认为藤山柳属和猕猴桃科的其它两个属都具有单珠被胚珠及其他相似的花药发育特征,这些特征和形态分类系统范畴的第伦桃科和山茶科有明显区别。因此,本文支持花粉形态学、细胞学和分子系统学的观点,认为藤山柳属与水东哥属和猕猴桃属构成一个较好的单系,一并放在猕猴桃科。     

嵩草属植物的胚胎学

对嵩草属（ Ｋｏｂｒｅｓｉａ） 植物进行了初步的胚胎学研究。该属植物具假四合花粉（ｐｓｅｕｄｏｍｏｎａｄ） ; 药室内壁在二核花粉时期开始螺旋状加厚, 花药表皮在花粉成熟时形成乳突; 成熟花粉具三细胞。胚珠为倒生型, 具厚珠心和双层珠被, 珠孔由内珠被构成, 珠柄的近基部向珠孔增生形成珠孔塞。胚囊的发育为蓼型, 四分体线形排列, 合点端大孢子发育成八核胚囊。受精后, 胚乳核先于受精卵进行分裂, 胚乳的发育为核型。胚的发育为柳叶菜型灯芯草变型。通过比较, 嵩草属植物大小孢子的发育、胚珠的结构、胚囊的发育、胚乳的发育和胚的发育与莎草科中其它类群一致。所以, 根据胚胎学资料, 嵩草属及其近缘属应保留在莎草科中,不该另立为嵩草科。     

The Embryology of the Genus Kobresia(Cyperaceae)

对嵩草属(Kobresia)植物进行了初步的胚胎学研究。该属植物具假四合花粉(pseudomonad);药室内壁在二核花粉时期开始螺旋状加厚,花药表皮在花粉成熟时形成乳突;成熟花粉具三细胞。胚珠为倒生型,具厚珠心和双层珠被,珠孔由内珠被构成,珠柄的近基部向珠孔增生形成珠孔塞。胚囊的发育为蓼型,四分体线形排列,合点端大孢子发育成八核胚囊。受精后,胚乳核先于受精卵进行分裂,胚乳的发育为核型。胚的发育为柳叶菜型灯芯草变型。通过比较,嵩草属植物大小孢子的发育、胚珠的结构、胚囊的发育、胚乳的发育和胚的发育与莎草科中其它类群一致。所以,根据胚胎学资料,嵩草属及其近缘属应保留在莎草科中,不该另立为嵩草科。     

小玉竹的胚胎学研究

小玉竹Polygonatum humile Fisch．ex Maxim．的花药四室．绒毡层腺质型,发育后期出现双核至多核。小孢子四分体左右对称型,偶见四面体型,胞质分裂连续型。成熟花粉具2细胞。子房3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。受精后,子房壁和外珠被细胞中含有草酸钙针晶。胚发育类似于紫菀型,基细胞有时纵裂形成两个子细胞。胚乳核型。根据实验结果,并结合前人的资料,本文提出了黄精属的胚胎学特征,并在此基础上对黄精族的概念以及属间系统关系进行了探讨。     

Effects of ovular secretions on pollen in Pseudotsuga menziesii (Pinaceae)

Effects of ovular secretions on pollen grains were examined in Pseudotsuga menziesii. The exine is cast off in the micropylar canal. A membranelike structure covers parts of pollen grains and appears to protect them. The outer intine consists of fibrous materials, but it also shows a thicker filamentous appearance in some ovules during pollen elongation. The inner intine is electron-dense. Its fibrous nature is occasionally visible. Dissolution of the outer intine varies in amount and manner in ovules from different trees. The plasma membrane near the pollen wall alternatively appears normal and distorted. These different morphologies of the outer intine and of the plasma membrane are considered to result from secretions from the ovule. The outer intine may contain electron-dense globules that are formed in the tube cell and traverse the inner intine. Pollen tube formation appears to be triggered by a secretion from the ovule. Cross-pollinated grains are less distorted compared with self-pollinated grains.     

Anther ontogeny in Campsis radicans (L.) Seem. (Bignoniaceae)

In this study anther ontogeny of Campsis radicans (L.) Seem. was investigated by transmission electron microscopy and light microscopy with special reference to the development of the anther wall. The anther wall formation follows the dicotyledonous type. The differentiation in anther starts with the appearance of archesporial cells which undergo periclinal divisions to give primary parietal layer to the epidermal site and the primary sporogenous cells to the inside. The primary parietal layer also divides to form two secondary parietal layers. Later, the outer secondary parietal layer (spl1) forms the endothecium and the middle layer by periclinal division whereas the inner one (spl2) directly develops into the outer tapetum forming the inner most layer of the anther wall. The sporogenous tissue is generally organized in two rows of cells with a horseshoe-shaped outline. The remainder of the tapetum lining the sporogenous mass is derived from the connective tissue. The tapetum thus has dual origin and dimorphic. Anthers are tetrasporangiate. The wall of the anther consists of an epidermis, endothecium, middle layer, and the secretory type tapetum. Tapetal cells are usually binucleated. Epidermis and Endothecium layers of anther wall remain intact until the end of anther and pollen development; however, middle layer and tapetum disappear during development.     

Embryology of the dioecious Woonyoungia septentrionalis (Magnoliaceae)

The embryological characteristics and ovular integument development of the dioecious species Woonyoungia septentrionalis (Dandy) Law (Magnoliaceae), which are poorly understood, were investigated under laser scanning confocal microscope (LSCM) and light microscope (LM). The embryological characteristics conform to most of the previously studied species in Magnoliaceae. The anther has 4 microsporangia, and the anther wall develops according to the dicotyledonous type. Cytokinesis at meiosis of the microspore mother cells follows a modified simultaneous type, giving rise to isobilateral or decussate tetrads, and a cell plate is absent, but a membrane was observed. Mature pollen grains are 2‐cellular and have high germination rates. The ovule is anatropous, crassinucellate and bitegmic, and meiotic result in linear tetrads of megaspores, the one at the chalazal end functions directly as an embryo‐sac cell. The development of the embryo sac is of the Polygonum‐type and endosperm formation is of the nuclear type. The outer integument of the ovule differentiates into an outer fleshy and an inner stony layer while the inner integument is reduced to a tanniniferous layer. The normal embryological development, high germination rates of pollen and high seed set indicate that the primary reason for the decline of the species is not to be found in these developmental processes.     

Embryology of the Theaceae - anther and ovule development of Camellia, Franklinia, and Schima

The anther and ovule development of Camellia, Franklinia, and Schima (Theaceae, Camellioideae) were observed. The three genera share the following embryological traits: anther wall formation of basic type, tapetum of glandular type, walls of endothecial cells with secondary thickening, and production of pseudopollen grains in connective, which are dispersed into pollen sacs at anthesis, ovule bitegmic-tenuinucellate, micropyle formed by inner integument alone, hypostase present, and both integuments generally five-to-seven cell layered. One autapomorphy of the Camellioideae found in the present study is the production of pseudopollen. The three genera surveyed differ with respect to the number of middle layers in the anther, the presence or absence of stomata on connective epidermis, morphology of pseudopollen, type of embryo sac formation, form of ovule, ovular vasculature, and the proliferation of ovular epidermis, etc. Among the three genera, Franklinia and Schima are presumed to be closer embryologically, and Schima possesses more numerous specialized features.     

Anther wall layers control pollen sugar nutrition inLilium

Summary Anthers ofLilium were for the first time investigated at the ultrastructural level in order to appreciate the possible ways of sugar transport in the microsporangium. Our results have shown that the cells of the outer anther wall layers and the cell of the connective were interconnected by plasmodesmata, thus allowing assimilates to travel through the symplasmic pathway from the vascular bundle to the most internal middle layer (ML 1). ML 1 was devoid of cell communication throughout pollen development. Tapetal cells were also lacking plasmodesmata on their external face towards ML 1, but adjacent tapetal cells developed lateral junctions: the tapetum could represent a syncytium. Sugars destinated to pollen in the loculus have then to cross the ML 1 and the tapetal layers by the apoplasmic pathway; it is suggested that these two envelopes could be involved in the control of sugar transport from the outer anther wall layers to the locular fluid. Before microspore mitosis, the tapetum degenerated but ML 1 remained structurally unchanged. During pollen development, the guard cells of stomata were lacking cell communication, and preserved their starch content, which could be the sign of photosynthesis within the anther wall. In order to check whether these structural disconnections in anther tissues corresponded to physiological barriers, isolated pollen and stamens were cultivated during the anther maturation phase, on a medium containing increasing concentrations of sucrose (0 M, 1/6 M, 1/2 M, 1 M). After 7 days of culture, isolated pollen was engorged with starch grains and was unable to germinate, whereas in cultivated stamens, pollen did not contain any starch grain: sporophytic tissues, however, accumulated abnormal amylaceous reserves. These results strongly suggest that the anther wall layers, in particular ML 1, starve pollen with sugars during its maturation. They are acting as a physiological buffer storing nutriment surplus in starch grains.Abbreviations ML 1 middle layer 1 - ML 2 middle layer 2 - PAS periodic acid Schiff - PATAg periodic acid thiosemicarbazide silver nitrate     

Embryology of Plagiopteron suaveolens Griffith (Plagiopteraceae) and its systematic implications

A study of the embryology of Plagiopteron suaveolens Griffith is presented in order to evaluate the affinities of the genus. Anther wall formation is of the dicotyledonous type. The anther tapetum is glandular and its cells become two to four nucleate. Cytokinesis in the microspore mother cell is simultaneous and the resultant tetrad is tetrahedral. The mature pollen grains are two-celled. The anther has 4-locules at anthesis. The ovule is anatropous, bitegmic and weakly crassinucellate with only one cell-layered parietal tissue. The micropyle is zig-zag in section and formed by both inner and outer integuments which are three and three to four cell layers thick respectively. The megaspore archesporium is one-celled and the embryo sac development is of the Polygonum type. An endothelium is formed with early disintegration of nucellar tissue. The antipodals multiply to 15 to 20 cells. Embryological evidence supports the placement of Plagiopteron in its own family, Plagiopteraceae, with closest relationship with Celastraceae and close relationship with Elaeocarpaceae, Rhizophoraceae and some families of the Geraniales.     

白毛新木姜子[Neolitsea aurata var.glauca]胚胎学研究

应用光学显微镜对白毛新木姜子的胚胎学特征进行了研究,首次在非寄生性樟科植物中发现了细胞型胚乳。对樟科8属进行了胚胎学特征的比较。花药四室,药室壁的发育属于"基本型",周原质团型绒毡层。小孢子母细胞连续型分裂。等四面体型四分体。二细胞成熟花粉,无孔沟。雌孢原多个,一般仅一个能继续发育。蓼型胚囊。助细胞具丝状器。反足细胞宿存。大孢子母细胞和合子具极性。宿存的一个助细胞具有吸器功能。细胞型胚乳,胚胎发育属于柳叶菜型的三叶变型。种皮源于外珠被,内表皮细胞壁螺旋状加厚。胚胎学特征表明,新木姜子属与木姜子属有密切的亲缘关系。较多的双胚囊异常现象,支持樟科与Monimiaceae具有紧密关系的推测。胚胎学特征不支持将无根藤属独立为科的观点。     

白毛新木姜子[Neolitsea aurata var. glauca]胚胎学研究

应用光学显微镜对白毛新木姜子的胚胎学特征进行了研究,首次在非寄生性樟科植物中发现了细胞型胚乳。对樟科8属进行了胚胎学特征的比较。花药四室,药室壁的发育属于“基本型”,周原质团型绒毡层。小孢子母细胞连续型分裂。等四面体型四分体。二细胞成熟花粉,无孔沟。雌孢原多个,一般仅一个能继续发育。蓼型胚囊。助细胞具丝状器。反足细胞宿存。大孢子母细胞和合子具极性。宿存的一个助细胞具有吸器功能。细胞型胚乳,胚胎发育属于柳叶菜型的三叶变型。种皮源于外珠被,内表皮细胞壁螺旋状加厚。胚胎学特征表明,新木姜子属与木姜子属有密切的亲缘关系。较多的双胚囊异常现象,支持樟科与Monimiaceae具有紧密关系的推测。胚胎学特征不支持将无根藤属独立为科的观点。     

延龄草(Trillium tschonoskii Maxim.)的胚胎学研究初报Ⅰ.——大孢子的发生及雌配子体的形成

本文描述延龄草(Trillium tschonoskii Maxim.)的大孢子发生,雌配子体的形成和雄配子体的形态。胚珠为倒生型,双珠被,厚珠心型。胎座为侧膜胎座向中轴胎座的过渡类型,胶囊发育为葱型的变异型。孢原细胞直接发生于幼胚珠的珠心表皮细胞之下,孢原细胞平周分裂,形成初生周缘细胞及初生造孢细胞。初生周缘细胞分裂先于初生造孢细胞,分裂结果与珠心表皮细胞共同形成了珠心组织。初生造孢细胞进一步发育,形成大孢子母细胞。大孢子母细胞经减数第一次分裂后,即出现壁,形成二分体。一般是珠孔端二分体细胞小于合点端二分体细胞,但偶尔也见到前者大于后者的情况。在二分体形成后珠孔端二分体细胞立即退化、或经减数第二次分裂后再退化(该次分裂多为斜向的)。合点端二分体细胞发育,经二核胚囊,四核胚囊,六核胚囊阶段至成熟胚囊。一般在珠孔端的周围淀粉粒丰富,并先于合点端的核进行分裂。珠孔端由二个助细胞,一个卵细胞构成卵器,助细胞具钩突,并具丝状器,两个极核。合点端常见多核仁的大核,成熟胚囊未见八核。成熟花粉粒为二细胞的,花药壁具变形绒毡层,花粉中充满淀粉粒。沼生目型胚乳。     

LEVER ACTION ANTHERS AND THE FORCIBLE SHEDDING OF POLLEN IN TORENIA (SCROPHULARIACEAE)

The anthers of Torenia fournieri were found to shed pollen forcibly by lever action. Anther structure was modified for this function by a flangelike outgrowth of the lateral pollen sac wall forming a lever. When pressed, this lever causes an infolding of the thinner, subadjacent, pollen sac wall forcing pollen from the stomium. A force of 1–1.5 g pressing against the four levers of an anther pair resulted in the forcible shedding of 2,000–3,000 pollen grains in two parallel rows. During the 2-day anthesis the flowers shift from functioning as males to hermaphroditic outcrossers, and yet only have a pollen:ovule ratio of 98.6, a ratio more indicative of facultative autogamy. The outermost pair of anthers functions on the first day of anthesis, while the second, inner pair functions on both days. In each flower, the 2-day anther pair produces approximately twice as many pollen grains as the 1 -day anther pair, a pollen production highly correlated with the length of their functional lives. This difference in pollen production is apparent in the larger size of the 2-day anthers, a size difference that first appears with the initiation of the anther primordia.