凤丫蕨孢子壁的结构和发育研究

利用光镜、扫描电镜和透射电镜对裸子蕨科（Hemionitidaceae）凤丫蕨（Coniogramme japonica（Thunb.） Diels）孢壁的结构和发育进行了研究。结果表明,凤丫蕨孢子外壁表面光滑,由2层构成,即薄的内层和厚的外层。周壁分为周壁内层和周壁外层两部分,周壁内层中上部具辐射状排列的小柱状成分,周壁外层由鳞片和小球体疏松交织成平面或立体网状,由两层周壁共同构成孢子表面皱状纹饰的轮廓。探讨了凤丫蕨孢子周壁的来源,为孢粉学和蕨类植物系统演化研究提供基础资料。     

Ultrastructural study of spore wall morphogenesis inOphioglossum thermale kom. var.nipponicum (Miyabe et Kudo) nishida

Spore wall morphogenesis ofOphioglossum thermale var.nipponicum was examined by transmission electron microscopy. The spore wall of this species consists of three layers: endospore, exospore, and perispore. The spore wall development begins at the tetrad stage. At first, the outer undulating lamellar layer of the exospore (Lo) is formed on the spore plasma membrane in advance of the inner accumulating lamellar layer (Li) of the exospore. Next, the homogeneous layer of the exospore (H) is deposited on the outer lamellar layer. Both lamellar layers may be derived from spore cytoplasm; and the homogeneous layer, from the tapetum. Then the endospore (EN) is formed. It may be derived from spore cytoplasm. The membranous perispore (PE), derived from the tapetum, covers the exospore surface as the final layer. Though the ornamentation of this species differs distinctly from that ofO. vulgatum, the results mentioned above are fundamentally in accordance with the data obtained fromO. vulgatum (Lugardon, 1971). Therefore, the pattern of spore wall morphogenesis appears to be very stable in the genusOphioglossum.     

ULTRASTRUCTURAL STUDY ON MICROSPORE WALL MORPHOGENESIS IN ISOETES JAPONICA (ISOETACEAE)

Spore wall morphogenesis of the microspore of Isoetes japonica was studied by transmission electron microscopy. The microspore wall consists of four layers: the perispore, outer exospore, inner exospore, and endospore. The perispore consists of electron-dense materials. The exospore is divided into outer and inner sections, with a large gap between the two. The outer exospore appears as an undulating plate consisting of tripartite lamellae with homogeneous sporopollenin. The inner exospore consists of an accumulation of tripartite lamellae on the microspore cell membrane. Immediately after meiosis, the tripartite lamellae of the outer exospore forms around the microspore. The lamellated inner exospore forms next, which adheres to the cell membrane of the microspore. The deposition of homogeneous sporopollenin material on the tripartite lamellae causes the plates of the outer exospore to thicken. Some homogeneous material may also be deposited on the inner exospore. Lastly, the electron-dense perispore is deposited on the outer exospore, and the electron-lucent endospore forms beneath the inner exospore. We conclude that the lamellae of the outer exospore, inner exospore, and endospore are formed and derived, in that order, from the gametophytic microspore cytoplasm. The homogeneous sporopollenin material of the outer exospore and perispore may be derived from the sporophytic tapetal cytoplasm.     

蜈蚣草孢壁发育及其系统学意义

利用光镜、扫描电镜和透射电镜对凤尾蕨科(Pteridaceae)蜈蚣草(Pteris vittata L.)孢壁的形成和发育进行研究。结果表明:蜈蚣草孢子四面体型,极面观钝三角圆形,赤道面观半圆形或超半圆形,近极面具瘤状纹饰和近极脊,远极面具脊并连成网状,具赤道环;孢子具乌毛蕨型外壁,由外壁外层构成纹饰的轮廓;实心型周壁由2层构成,且内层薄、外层具小球体。结合孢子外壁和周壁的发育特征,认为凤尾蕨科与裸子蕨科和水蕨科的亲缘关系较近,支持将裸子蕨科和水蕨科置于凤尾蕨科。     

红盖鳞毛蕨孢子发育的超微结构和细胞化学研究

采用透射电镜和细胞化学技术对红盖鳞毛蕨(Dryopteris erythrosora(Eaton)O.Ktze.)的孢子发育过程进行了研究,根据超微结构和细胞化学特征可将其孢子发育过程分为3个阶段:(1)孢子母细胞及其减数分裂阶段:孢子母细胞壳在孢原细胞末期开始形成,位于孢子母细胞及其减数分裂形成的四分体外侧,PAS反应显示其为多糖性质,与胼胝质壁为同功结构;在减数分裂形成的四分孢子之间产生孢子外壳,从功能、形成位置和时间上看与胼胝质壁相似,但苏丹黑B反应显示其可能含有脂类物质,与孢子母细胞壳和胼胝质壁不同。(2)孢子外壁形成阶段:外壁为乌毛蕨型(Blechnoidal-type),由薄的多糖性质的外壁内层和表面平滑的孢粉素外壁外层构成;小球参与外壁外层的形成,组织化学分析显示小球的中央区域和外壁外层内侧部分由红色(多糖)变为黄色,小球的表面区域和外壁外层部分始终被染成黑色(脂类),可知小球与外壁同步发育。(3)孢子周壁形成阶段:周壁为凹陷型(Cavate-type),包括2层,内层薄,紧贴外壁,外层隆起形成孢子脊状褶皱纹饰的轮廓,以少见的向心方向发育;苏丹黑B和PAS反应观察周壁被染成橙色,推测其可能由多糖等成分构成;孢子囊壁细胞参与周壁的形成。本研究为揭示蕨类植物孢子发生的细胞学机制提供了新资料。     

紫萁孢子囊发育中多糖和脂滴的细胞化学观察

采用光镜、透射电镜和细胞化学技术,对紫萁孢子囊发育过程中孢壁的超微结构和孢子囊内多糖和脂滴的分布及其动态变化进行研究,以探讨紫萁孢子囊发育过程中多糖和脂滴的代谢特征,为蕨类孢子发生的研究提供基础资料。结果表明:(1)紫萁孢子囊由1层囊壁细胞、2层绒毡层和产孢组织构成。(2)紫萁孢子壁由发达而分2层的外壁(外壁内层和外壁外层)和薄的不连续的周壁构成,由外壁形成棒状纹饰的轮廓;孢子外壁内层由多糖类物质构成,外壁外层和周壁均含有脂类物质。(3)在紫萁孢原细胞中观察到少量脂滴;随着紫萁孢壁的形成,囊壁细胞中淀粉粒的大小逐渐变小、数目先增加后减少,它们转运到内层绒毡层原生质团并转化为孢粉素前体物质,再穿过原生质团内膜表面进入囊腔,成为孢粉素团块或以小球形式填加到孢子表面形成孢壁。(4)紫萁孢子囊将多糖类营养物质转化为脂类,以脂滴的形式储藏在孢子中。     

乌蕨孢子壁的形成和发育

利用光镜、扫描电镜和透射电镜对鳞始蕨科（Lindsaeaceae）乌蕨（Stenoloma chusanum Ching）孢壁的形成和发育进行了研究。结果表明乌蕨孢子两侧对称、单裂缝,表面具疣状纹饰。孢壁由内壁、外壁和周壁三部分构成。外壁在四分体阶段已基本形成,其表面光滑,质地均匀,由孢粉素形成。周壁是由绒毡层残余物在外壁表面沉积形成,可分为周壁内层、周壁中层和周壁外层三部分。在周壁中层与外层之间有一层均匀的空间。最后,本文探讨了孢壁的形成和发育规律,研究结果对揭示孢子纹饰和孢壁各层的形成过程、来源和稳定性有重要的意义,并为孢粉学和系统学研究提供基础资料。     

乌蕨孢子壁的形成和发育

利用光镜、扫描电镜和透射电镜对鳞始蕨科(Lindsaeaceae) 乌蕨( Stenoloma chusanum Ching) 孢壁的形成和发育进行了研究。结果表明乌蕨孢子两侧对称、单裂缝, 表面具疣状纹饰。孢壁由内壁、外壁和周壁三部分构成。外壁在四分体阶段已基本形成, 其表面光滑, 质地均匀, 由孢粉素形成。周壁是由绒毡层残余物在外壁表面沉积形成, 可分为周壁内层、周壁中层和周壁外层三部分。在周壁中层与外层之间有一层均匀的空间。最后, 本文探讨了孢壁的形成和发育规律, 研究结果对揭示孢子纹饰和孢壁各层的形成过程、来源和稳定性有重要的意义, 并为孢粉学和系统学研究提供基础资料。     

朝鲜介蕨孢子周壁发育的研究

利用光镜、扫描电镜和透射电镜对朝鲜介蕨[Dryoathyrium coreanum(Christ)Tagawa=Lunathyrium coreanum(Christ)Ching]孢子周壁的发育规律进行了研究。结果表明,朝鲜介蕨孢子两侧对称,单裂缝,表面具粗大的脊状褶皱,褶皱形成网状或拟网状纹饰。孢壁包括内壁、外壁和周壁。孢子外壁表面光滑,在四分孢子时期就已发育成熟。四分孢子分离后,周壁开始形成,周壁来源于孢子囊的绒毡层,是由原质型绒毡层的残余物在外壁上沉积而成。成熟的周壁很厚,可分为外层和内层。周壁内有大的空腔,主要是由周壁外层向外隆起形成的,隆起进而形成了孢子的脊状褶皱和表面纹饰。     

瓦韦孢子壁的结构和发育的研究

利用光镜、扫描电镜和透射电镜对水龙骨科（Polypodiaceae）瓦韦(Lepisorus thunbergianus (Kaulf.) Ching)孢子壁的结构和发育进行了研究。研究结果表明瓦韦孢子两侧对称、单裂缝,表面具波纹状纹饰。孢壁从内到外由内壁、外壁和周壁三部分构成。外壁来源于绒毡层物质,由外壁内层和外壁外层构成,外壁外层表面的波纹状纹饰形成孢子表面的纹饰轮廓。周壁薄,紧贴外壁表面,由2层片状结构叠合而成。在外壁外层形成过程中,孢子表面和周围出现较多小球。本文探讨了孢壁各层的结构、来源和发育过程,为蕨类植物系统学和孢粉学研究积累资料。     

华中铁角蕨孢子纹饰形成的超微结构观察

利用透射电子显微镜对铁角蕨科(Aspleniaceae)华中铁角蕨(Asplenium sarelii Hook.)孢子及其纹饰的形成过程进行观察。结果表明:①华中铁角蕨孢子囊发育为薄囊蕨型;②孢子外壁表面光滑,远极面的外壁厚约0.8~1.1μm,近极面的外壁厚约1.4~1.8μm;③孢子周壁厚度约4~5μm,染色较外壁深,分为内层和外层;内层紧帖外壁表面,其上具柱状、瘤状或疣状突起;外层向外隆起形成脊状纹饰的轮廓,脊的下方具空腔,脊的顶端具翅;④铁角蕨型与鳞毛蕨型孢子外壁和周壁纹饰的形成过程具有相似性;⑤孢子的成熟度对于孢子形态的研究是至关重要的,只有完全成熟的孢子的表面纹饰才是稳定的。     

ULTRASTRUCTURAL STUDY ON SPORE WALL MORPHOGENESIS IN LYCOPODIUM CLAVATUM (LYCOPODIACEAE)

Spore wall morphogenesis of Lycopodium clavatum was observed by transmission electron microscopy. The spore plasma membrane indicates the reticulate spore sculpture shortly after meiosis. The mature spore wall of this species consists of two layers, inner endospore and outer exospore. There is no perispore in the sporoderm of this species. The exospore formation begins during the tetrad stage; and this layer is divided into two distinct sublayers, an outer lamellar layer and an inner granular layer. The lamellar layer is formed on the sculptured spore plasma membrane. Additional lamellae attach to this layer in a centripetal direction. For that reason, this layer may be derived from spore cytoplasm. The granular layer is formed only in the proximal region following lamellar layer formation, and it also may be derived from spore cytoplasm. The endospore is formed lastly and seems to be derived from spore cytoplasm as well. Accordingly, the spore sculpture of this species may be under the genetic control of the spore nucleus.     

Spore wall ultrastructure of Polypodiaceae from north-western Argentina

The spore wall ultrastructure of Campyloneurum, Microgramma, Pecluma, Phlebodium, Pleopeltis and Serpocaulum (Polypodiaceae) from north-western Argentina has been studied using transmission electron microscopy (TEM). The exospore is 0.4–3 μm thick, two-layered and variously ornamented in all taxa. The exospore surface is distinctive, but in general ultrastructure the exospore is similar in all species studied. The structural elements of the exospore consist of cavities in the inner part as well as channels with a radial orientation and channels at both sides of the laesura. Variation in the exospore surface was observed in spores at different stages of maturation. The perispore is darkly contrasted and 0.04–2 μm thick. Three different structure types were recognised, including fibrillar, multilamellar and lacunose. Scattered globules and spherules were always present on the perispore surface. The structural variability of the perispore was surveyed within complete sporangia. We concluded that the observed variability may be related to the stage in spore maturation and, consequently, to the stages in perispore differentiation. As the exospore ultrastructure is similar and interpreted as related to functional activity in the studied material, it cannot be used for systematic delimitations at this generic or specific level.     

狗脊孢壁发育超微结构的研究

鳞毛蕨型孢子类型众多,初步研究表明形态相似的孢子类型其孢壁发育特征存在差异,因此有必要对各代表类群的孢壁发育进行深入地研究。该文利用透射电镜对乌毛蕨科(Blechnaceae)狗脊(Woodwardia japonica)孢壁结构和发育的超微结构进行研究。结果表明:(1)狗脊孢子囊的结构由外向内分别为孢子囊壁细胞、两层绒毡层细胞和孢子母细胞;(2)狗脊孢子具乌毛蕨型(Blechnoid type)外壁,表面光滑,由两层构成,裂缝区域具辐射状的槽;(3)周壁属于空心型(cavity type),由四层构成,从内向外分别为P1、P2、P3和P4层,前三层叠合在一起,层间有不同程度的空隙,P4层与前三层之间具有明显而连续的空腔,并隆起形成片状褶皱纹饰;(4)有小球体和小杆共同参与孢子周壁的形成,周壁部分或全部来源于孢子囊壁细胞。综上所述,狗脊孢子与同属于鳞毛蕨型的贯众(Cyrtomium fortunei)和朝鲜介蕨(Dryoathyrium coreanum)孢壁的发育在周壁结构、周壁各层的发育顺序、周壁来源和参与成壁的特征物质等方面存在差异。该研究有利于进一步理解蕨类植物孢壁所蕴含的分类和演化上的科学意义和价值。     

Palynology of South American Argyrochosma and Notholaena (Pteridaceae) species

The palynology of the South American taxa Argyrochosma chilensis (J. Rémy) Windham, A. nivea (Poir.) Windham, var. nivea , var. flava (Hook.) Ponce, var. tenera (Hook. ex Gillies) Ponce and A. stuebeliana (Hieron.) Windham; N. sulphurea (Cav.) J. Sm. and N. galapagensis Weath. & Svenson has been investigated. These species show differences in spore size, shape, sporoderm thickness and structure. In both genera, the exospore is psilate and the perispore has either cristate-reticulated or reticulated ornamentation, with a complex structure and stratification. The perispore presents several characteristics useful in establishing differences valuable for taxonomic purposes. The investigated species of Argyrochosma have a perispore with a middle stratum composed of radial rodlets, and an outer continuous stratum, which bears the elements of the sculpture. These are independent of the inner structure. The spores of the investigated Notholaena species have a thick, complex, three-stratified perispore, with an outer discontinuous stratum. The middle stratum is composed of threads ramified at several levels and laterally fused. The elements of the sculpture show continuity with those of the structure. Granular material of sporopolleninous composition fills the lumina at the surface. Abnormal spores and 32 spores per sporangium were frequent in specimens of A. nivea var. nivea and N. sulphurea .     

海金沙孢子壁结构和发育的研究

利用光镜、扫描电镜和透射电镜对海金沙科(Lygodiaceae)海金沙[Lygodium japonicum (Thunb.) Sw.]孢壁的形成和发育进行了研究.结果表明:海金沙孢子壁由内壁、外壁和周壁3部分构成.外壁由2层构成,即薄的内层和厚的外层,其中外层是在四分体分离前通过孢粉素的逐层沉积并浓缩凝聚而形成的均质层,其表面具不明显的疣状突起.周壁由绒毡层残余物在外壁表面逐层沉积形成,可分为周壁内层、周壁中层和周壁外层3部分;周壁中层具辐射状排列的长条形成分,周壁外层形成瘤状纹饰的轮廓.本研究为孢粉学和蕨类植物系统演化分析提供基础资料.     

中国蹄盖蕨属植物孢子形态的研究

利用扫描电子显微镜对我国产蹄盖蕨属44种植物的孢子进行了观察。结果表明,该属孢子形态为单裂缝,两侧对称,极面观为椭圆形,赤道面观为豆形。外壁表面光滑,由周壁形成表面纹装饰。根据周壁的结构和表面纹饰,可分为两种类型;一是周壁外层发达,形成粗大的脊状纹饰,有11种属此类型;二是周壁外层很薄或不完全发育,由周壁内层或中层形成表面纹饰,有33种属此类型纹饰。本文还就本属的孢子形态特征以及与本属的属下分类关系、本属与邻近属的关系等进行了讨论。     

Spore morphology and wall ultrastructure of Hymenophyllaceae Link (Pteridophyta) from north-west Argentina

The family Hymenophyllaceae is represented in the study area by six species in two genera, Hymenophyllum J. E. Smith and Trichomanes L. The study was based on herbarium material and spores were studied under light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). Both genera have trilete spores, 23 to 45 μm in equatorial diameter, with an ornamentation of echinulae and cones in Hymenophyllum and of verrucae, gemmae and granules in Trichomanes. Mature spores have a sporoderm composed of a perispore, an exospore and a fibrillar endospore; the exospore is 0.5 to 2.5 μm thick, compact and with an irregular margin. In some cases radial channels and other channels associated with the middle and inner parts of the laesurae were evident. A series of cavities filled with an opaque content line the inner margin of the exospore. The perispore is 20 to 400 nm thick and unevenly differentiated along the surface of a same spore. Under TEM, two main differentially contrasted portions could be distinguished: a dark massive portion with structural components could not be distinguished, and a light portion with several plates arranged in piles. The inner surface of the perispore exhibit short scales. Globules are immersed within the perispore at some depth from the perispore surface and others connected to it by structural threads. The spore characters observed including shape, ornamentation, laesurae length and wall structure are useful in distinguishing the two genera studied, but less useful in differentiation at the species level.     

团扇蕨孢子发生和发育的显微观察

利用光学显微镜对膜蕨科（Hymenophyllaceae）团扇蕨(Gonocormus minutus(Blume) Bosch)孢子的发生和发育进行了观察。研究结果表明：团扇蕨孢子为多边圆形,三裂缝不明显,外壁表面光滑,周壁薄,紧贴外壁表面,由周壁形成乳头状或颗粒状纹饰。在外壁形成后期,孢子表面和囊腔中出现大量小球;在周壁形成时期,孢子表面和周围出现较多小球体;小球和小球体参与孢子壁的形成。团扇蕨绒毡层为混合型,内层为周原质团绒毡层;外层为腺质型绒毡层。本文为膜蕨科系统演化和发育生物学研究提供依据。     

Structure of wall layers in Selaginella kraussiana microspores (Lycophyta)

A similarity was found in both construction and ultrastructure between the two exospore layers in microspores of Selaginella kraussiana. The exospore is made up of two different kinds of rods. One of the kinds of rods are large, 100–150 nm in width, while the other are tubular rods 10–15 nm in diameter. The large rods are wider at the base of the spines than in the upper part, possibly due to flattening or compression. Both the outer and the inner exospores have a stranded surface that is very pronounced in the microspores of this species. Fibrous strands persisting the scanning electron microscope and transmission electron microscope (TEM) fixations were observed on the spore surface proximally and through perforations (exospore channel openings). This net of fibres penetrates and fills the space of the cavities within large channels through the outer and inner exospore and within the gap. According to our interpretation, these strands would be produced by the tapetum and are probably related to the nourishment of the developing microspores. Contrast varies in TEM sections after cytochemical stains, but this appears to be due to transitory substances, e.g. carbohydrates, rather than to be a substantial difference in basic composition between inner and outer exospore layers.