中国球子蕨科植物孢子形态研究

通过扫描电镜观察,描述了我国球子蕨科4种及分布北美洲的1种植物属种孢子形态特征。根据孢子形态及周壁纹饰特征,探讨种分类归属及等级处理问题。     

球子蕨孢子的无菌繁殖

以球子蕨成熟孢子为外植体,研究了不同激素及浓度对其孢子萌发、愈伤组织诱导、丛生芽分化及生根的影响。结果表明：孢子萌发最适培养基为1／2MS＋2％蔗糖,20d后萌发率达55．7％;诱导愈伤组织的最适培养基为MS＋0．5mg·L-1 KT＋0．5mg·L～2,4-D,诱导率达36％,愈伤组织为绿色颗粒状;颗粒状愈伤组织在不添加激素的MS培养基中即可生长出大量丛生芽,转化率可达49．3％;低浓度（0．2mg·L-1）的IAA可有效促进幼孢子体苗生根。     

球子蕨孢子的无菌繁殖

以球子蕨成熟孢子为外植体,研究了不同激素及浓度对其孢子萌发、愈伤组织诱导、丛生芽分化及生根的影响。结果表明:孢子萌发最适培养基为1/2MS+2%蔗糖,20d后萌发率达55.7%;诱导愈伤组织的最适培养基为MS+0.5mg·L-1KT+0.5mg·L-12,4-D,诱导率达36%,愈伤组织为绿色颗粒状;颗粒状愈伤组织在不添加激素的MS培养基中即可生长出大量丛生芽,转化率可达49.3%;低浓度(0.2mg·L-1)的IAA可有效促进幼孢子体苗生根。     

中国球子蕨科植物化学分类研究

本文对中国球子蕨科2属4种植物的乙醇提取物进行纸层和薄层析分析。发现其主要化学成分黄酮类化合物的分布与科、属、种的分类有一定相应性,为进一步研究分类问题提供化学证据。     

蕨类植物桂皮紫萁颈卵器和精子器形态和发育的研究

利用扫描电镜技术和树脂切片技术对蕨类植物桂皮紫萁（Osmunda cinnamomeaL.var.asiatica Fernald)的颈卵器和精子器的形态和发育进行了细致的研究。颈卵器发生于雌配子体的腹面,颈部由4列壁细胞构成,6-7个细胞高,内部含有颈沟细胞,腹沟细胞和卵细胞,卵细胞在整个发育过程中,造粉体和囊泡最为显著,颈卵器内的卵细胞成熟时产生卵膜和分离腔。精子器发生于雄配子体的边缘及腹面,由7-8个壁细胞螺旋状围绕而成,壁细胞内为产精组织,精子成熟时精子器盖细胞开裂释放出游动精子。     

朝鲜蛾眉蕨配子体形态发育的研究

朝鲜蛾眉蕨配子体形态发育的研究刘保东,王志宏（哈尔滨师范大学生物系,哈尔滨１５００８０）ＯＢＳＥＲＶＡＴＩＯＮＯＮＴＨＥＦＯＲＭＡＬＤＥＶＥＬＯＰＭＥＮＴＯＦＧＡＭＥＴＯＰＨＹＴＥＯＦＬＵＮＡＴＨＹＲＩＵＭＣＯＲＥＡＮＵＭ￥ＬｉｕＢａｏ－ｄｏｎｇ;Ｗ...     

绵马鳞毛蕨精母细胞和游动精子超微结构特征的研究

应用电镜技术对蕨类植物绵马鳞毛蕨(RYOPTERIS CRASSIRHIZOMA Nakai)精母细胞和游动精子的超微结构特征进行了研究。精母细胞为多边形,细胞质内含有丰富的线粒体、质体、内质网、高尔基体等常见的细胞器．在细胞质中还可见到一些同心圆膜状结构,位于质膜的附近或精母细胞的角偶。同心圆膜状结构由双层膜环绕构成,外被l层单位膜。精母细胞与精子器的璧细胞之间形成了分离腔。在精母细胞质膜外形成了嗜锇层,这些结构的形成说明精母细胞已经开始与雄配子体逐渐分离,进入独立发育的阶段。尽管精母细胞之间也有嗜锇层的形成,但嗜锇层是不连续的,其上有一些空隙,精母细胞之间可通过空隙进行物质和信息的交流。成熟的精子细胞外被l层透明的薄膜,里面为游动精子。螺旋状。由环状细胞器环绕3～4圈构成．这些环状细胞器包括多层结卡构、微管带、巨大线粒体、鞭毛带和1个长形浓缩的细胞核。游动精子的后端为一些泡囊化的细胞质．其中包括一些残存的线粒体、造粉质体及大的囊泡等。当成熟的精子细胞排出精子器后。其内的游动精子挣脱透明质膜的束缚,摆脱后端的囊泡,成为1条游动精子。本文还对绵马鳞毛蕨和其它蕨类植物精子的超微结构特征进行了比较。     

竹叶蕨配子体发育的培养观察

首次在光学显微镜下观察竹叶蕨孢子及其萌发、丝状体发育、片状体和生长点的形成及分化、原叶体细胞形态、假根及性器的发育等方面所表现出的显微特征。初步讨论竹叶蕨科从鳞始蕨科中分立出来的合理性,以及原叶体边缘细胞的形态、叶绿体对光的敏感性、假根的形态和精子器的形成及分化的系统学意义。     

巢蕨配子体的新观察

在不添加任何外源激素的条件下,用水来隔绝空气,即在试管中沉水条件下培养狭翅巢蕨(Neottopteris antrophyoides (Christ) Ching)的孢子,首次成功地诱导出极端简化的雄性配子体,简化程度几乎与被子植物的花粉粒相当,只由1个营养细胞、1条假根和1个精子器组成。本文讨论了在高等植物生活史系统演化方面,环境因素可能起到的作用。     

隐子蕨属（水龙骨科）植物在中国的首次承认

首次承认水龙骨科（Polypodiaceae）隐子蕨属（Crypsinus）植物在中国的分布。文中列出了该属与假瘤蕨属（Phymatopteris）和修蕨属（Selliguea）的区别特征,给出隐子蕨属植物在中国的唯一一种——三指隐子蕨（Crypsinus trilobus）的文献引证,特征描述并附图。     

Effects of caffeine on germination and differentiation in spores of the fern, Onoclea sensibilis

During spore germination in the fern, Onoclea sensibilis L., the nucleus moves from a central position to one end, and an asymmetrical cell division partitions the spore into two cells of greatly unequal size. The smaller cell differentiates directly into a rhizoid, whereas the larger cell and its derivatives give rise to the prothallus. In the presence of 5 mM caffeine, the nuclei of most of the spores undergo mitotic replication, whereas cell wall formation is blocked. Multinucleate single cells are produced, which are capable of growth, but no rhizoid differentiation occurs. In some cases a partial cell wall is produced, but the nucleus moves through the discontinuity back to the center of the spore, and the enucleate, incompletely partitioned small “cell” fails to differentiate into a rhizoid. In less than 1% of the spores a broad protuberance, whose wall is yellow-brown, is formed in a multinucleate single cell. The color, staining reaction to ruthenium red, and ultrastructural appearance of the protuberance resemble that of the rhizoid wall. It appears that infrequently in the caffeine-treated spores, a feature which is characteristic of rhizoids is expressed, in the absence of asymmetric cell division, in a cell which otherwise is unable to produce a rhizoid. The results are interpreted to mean that the spore has a highly localized, persistent differentiated region. For rhizoid differentiation to occur, a nucleus must be confined in that region – a confinement which normally is accomplished by the geometrically asymmetric first cell division of germination.     

Metal-binding sites in germinating fern spores (Onoclea sensibilis)

Summary During germination of the spore of the sensitive fernOnoclea sensibilis L. the nucleus migrates from a central position to the proximal face and then to one end of the ellipsoidal spore. An asymmetric cell division follows giving rise to a small cell which differentiates immediately into a rhizoid, and a large cell which divides further to give rise to the prothallus. The proximal face of the spore coat is differentiated from the remainder of the spore by its ability to bind nickel ions under certain conditions and by its staining with a sulfide-silver procedure which localizes heavy metals. The inner portion of the exine at the proximal face is differentiated from the outer part by its ability to stain with sulfide-silver at specific periods during germination. The exine at the proximal face also contains pore-like structures 50 nm in diameter which extend from the inner layer of the exine to the outer surface. Sulfide-silver staining material appears to be extruded through the pores at specific periods during germination. The percentage of spores showing nickel-binding and sulfide-silver stainability increases sharply during the first two to four hours of imbibition, then decreases sharply during the following two hours. This is followed by a second rise in staining at 8 to 12 hours of imbibition.The role of the ion-binding sites in the exine is discussed in relation to the stable polarity of the spore.Publishing prior to 1984 asAlix R. Bassel     

Effects of microtubule-inhibitors on nuclear migration and rhizoid differentiation in germinating fern spores (Onoclea sensibilis)

Summary Germinating spores of the sensitive fern,Onoclea sensibilis L., undergo premitotic nuclear migration before a highly asymmetric cell division partitions each spore into a large protonemal cell and a small rhizoid initial. Nuclear movement and subsequent rhizoid formation were inhibited by the microtubule (MT) inhibitors, colchicine, isopropyl-N-3-chlorophenyl carbamate (CIPC) and griseofulvin. Colchicine prevented polar nuclear movement and cell division so that spores developed into enlarged, uninucleate single cells. CIPC and griseofulvin prevented nuclear migration, but not cell division, so that spores divided into daughter cells of approximately equal size. In colchicine-treated spores, MT were not observed at any time during germination. CIPC prevented MT formation at a time coincident with nuclear movement in the control and caused a disorientation of the spindle MT. Both colchicine and CIPC appeared to act at a time prior to the onset of normal nuclear movement. The effects of colchicine were reversible but those of CIPC were not. Cytochalasin b had no effect upon nuclear movement or rhizoid differentiation. These results suggests that MT mediate nuclear movement and that a highly asymmetric cell division is essential for rhizoid differentiation.     

Red Light Stimulates an Increase in Intracellular Calcium in the Spores of Onoclea sensibilis

Red light (R) stimulates an increase in the total concentration of intracellular calcium in the spores of Onoclea sensibilis L. as determined by atomic absorption spectroscopy. Subsequent exposure to far-red light inhibits the R-induced increase in intracellular calcium. The majority of the increase occurs 5 minutes after the onset of irradiation. The calcium antagonist, La³⁺, inhibits both germination and the R-induced increase in intracellular calcium. The R-induced increase in calcium is sufficient to account for an increase in the concentration of intracellular calcium ions from 0.1 micromolar to 1 to 10 micromolar. Large detectable changes in other elements tested are not required for germination.     

Carbon Dioxide and Ethylene Control of Spore Germination in Onoclea sensibilis L

Regulation of spore germination in the fern Onoclea sensibilis L. was investigated by applying CO₂ alone and in combination with ethylene. Sterile spores were sown aseptically on Knops solution in loosely capped culture tubes, enclosed individually in 2-liter chambers, and grown under continuous white light. When maintained in enclosed containers with the ethylene-absorbent mercuric perchlorate and with atmospheres enriched up to 2% CO₂ (v/v), spores germinated without any inhibition. Higher levels of applied CO₂ were progressively inhibitory. Inhibition by CO₂ was reversible. When CO₂ was permitted to escape and spores were exposed subsequently to ambient laboratory air, recovery from inhibition occurred within 48 hours. Also, inhibition by CO₂ was specific, since the same degree of inhibition resulted regardless of whether spores were treated with exogenous CO₂ for 48, 72, or 96 hours. The effect on germination of 1 μl/l added ethylene depended upon the amount of applied CO₂. When containers of KOH were enclosed and ambient CO₂ was absorbed, inhibition of germination by 1 μl/l exogenous ethylene was 90%. When CO₂ was applied in concentrations from 0.25 to 1.0% (v/v), CO₂ increasingly antagonized the inhibitory action of 1 μl/l added ethylene. Thus, photoinduced germination of spores was regulated by competitively interacting levels of CO₂ and ethylene.     

Chloroplast activities of dark-imbibed and photoinduced spores of the fernOnoclea sensibilis

Summary Chloroplast activities of dark-imbibed (non-germinating) and photoinduced (germinating) spores of the sensitive fern,Onoclea sensibilis were compared to gain insight into the germination process. There were no changes in the number of chloroplasts or in the chlorophyll contents of the spore during dark-imbibition and during the early phase of germination. Levels of increase in the Chloroplast DNA content of dark-imbibed and photoinduced spores were nearly the same and were associated with autoradiographic incorporation of [³H]thymidine into the cytoplasm. However, incorporation of the label into the nucleus occurred only during photoinduction of spores. Analysis of Chloroplast and nuclear DNA contents by dot-blot hybridization with labeled gene-specific probes has confirmed that chloroplast DNA content of the spore increases during dark-imbibition and photoinduction, while increase in nuclear DNA occurs only in photoinduced spores. Chloroplasts isolated from dark-imbibed and photoinduced spores incorporated [³H]TTP into an acid-insoluble fraction identified as DNA. The results show that physiological activities of chloroplasts of dark-imbibed and photoinduced spores ofO. sensibilis are similar and support an exclusive role for nuclear DNA synthesis in spore germination.