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。     

褶纹冠蚌精子球的形态和超微结构观察

利用光镜和电镜技术研究了褶纹冠蚌精子球的形态和超微结构.结果表明:精子球呈球形,直径约65-70μm,容纳2300多个精子.从外向内,精子球由非细胞层、表面层和内部区组成.非细胞层薄,厚约0.6μm,易碎.表面层厚约7.5μm,被分隔成许多辐射状排列的小室,单个精子头部位于小室内,指向精子球的中央,而精子的单个鞭毛由精子球的表面伸出.精子质膜在鞭毛领处与表面层相连,相邻精子间无细胞质桥相连.内部区呈球状,内含絮状物质.精子球从雄蚌出水管排出后,位于精子球外周的鞭毛沿固定方向不停地摆动,精子球翻滚着向前运动,且单个精子依次从精子球上脱落下来,最后精子球成为一中空的球,历时120h.     

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.     

Early development in fern gametophytes: interpreting the transition to prothallial architecture in terms of coordinated photosynthate production and osmotic ion uptake

Gametophytes of Onoclea sensiblis L. were grown under various light and media-ion conditions to gain a better understanding of the source/sink relationships between photosynthetic and ion-absorbing cells. There was a clear interdependency between green cell and rhizoid functions, such that the growth and development of the rhizoids was completely dependent on the internal delivery of photosynthates from green cells, and conversion of the one-dimensional filament into the two-dimensional prothallus required monovalent cations that could only be provided by rhizoid uptake. The need for monovalent cations was related to osmotic demands of dividing and expanding cells; prothallial development was blocked by monovalent cation deficiency, and the system resorted to Na+ uptake to support cell expansion when K+ was absent. Surgical excisions of filament cells further demonstrated the high degree of coordinated growth between the light-absorbing and ion-absorbing regions. It was also learned that excised sub-apical cells of the protonemata, like the intensively studied apical cell, were capable of remodelling remnants of the filament into a normal prothallus.     

Maintaining apical dominance in the fern gametophyte

A kinetic model is developed for cell differentiation in the fern gametophyte to test hypotheses on the role of spatially patterned plasmodesmata networks in development. Of particular interest is the establishment and maintenance of apical cell type in a single cell, with concurrent suppression of this character in all other cells (apical dominance). Steps towards understanding apical cell localization in geometrically simple gametophytes may shed light on the establishment and maintenance of apical meristems in higher plants. The model, based on the plasmodesmata maps of Tilney and colleagues and involving kinetics for a requisite minimum of two morphogens. successfully produces the apical/non-apical cell differentiation patterns of normal development, and redifferentiation due to cell isolation, in six stages from 0-30 d of development. Our results indicate that increasing apical cell plasmodesmata number, as development progresses, is not required for effective transport across apical cell walls in maintaining apical dominance.     

Different Patterns of Intercellular Transport of Lucifer Yellow in Young and Mature Antheridia of Chara vulgaris L.

Intra- and intercellular movement of the fluorochrome Lucifer Yellow (LY), microinjected into the shield cells of male sex organs, was examined at different stages of spermatogenesis in Chara vulgaris L. Two distinct stage-associated types of probe movement were noted: (I) a fast and uniform spreading of fluorescence within the shield cell injected, followed by centripetal transport of LY into the adjoining manubrium and the capitular cells, and subsequent redistribution into the other manubria and shield cells in young antheridia (up to the stage of 4-cellular filaments), and (II) limited spreading of fluorescence, restricted to the triangle-shaped area of the impaled shield cell in more mature antheridia with multicellular filaments. These results confirm earlier electron microscopic observations on plasmodesmatal connections indicating an intensive solute movement between all cell types in young antheridia of Chara. Developmental changes appearing at later stages, during differentiation of sperm cells, strongly reduce the capacity for intercellular symplasmic transport.     

苎麻疫霉雄器侧生性状的遗传研究*

在来自江苏、江西棉花、芒麻和构树的12个些麻疫霉（PhytophthoraboehmeriaeSawada）菌株中均观察到侧生雄器,其比率为4．0％～16．5％。在以菌株JS－5和PM－8（雄器侧生比率分别为16．5％和9．5％）为亲本所建立的连续2～3代单游动孢子无性系后代中,雄器侧生性状可以遗传,但单孢株间雄器侧生比率有一定差异,其分布范围分别为9．0％～34．0％和2．5％～15．5％。进一步诱导菌株JS－5的单游动孢子株的卵孢子萌发,分别对具侧生雄器和具围生雄器的藏卵器（卵孢子）进行单孢分离,检测雄器位置性状在由上述不同来源卵孢子萌发所形成的单卵孢株后代的遗传与变异。结果表明,无论是由具侧生雄器的藏卵器中的卵孢子萌发形成的单卵孢株,还是由具围生雄器的藏卵器中卵孢子萌发形成的单卵孢株,其有性器官均具有雄器侧生与雄器围生两种类型,但侧生比率在各代菌株间有很大差异。S1代单卵孢株的雄器侧生比率分布范围为1．0％～79．0％,其中具侧生雄器的藏卵器中卵孢子萌发形成的单卵孢株雄器侧生比率较高（分布范围7．0％～79．0％,平均33．6％）,而来自具围生雄器的藏卵器中的卵孢子萌发形成的单卵孢株雄器侧生比率较低（分布范围1．0％～32．0％,平均11．52％）。S2代单卵孢株的雄器侧生比率为10％～9