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.     

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.     

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 .     

水蕨孢子壁的形成和发育

利用光镜、扫描电镜和透射电镜对水蕨科(Parkeriaceae)水蕨(Ceratopteris thalictroides (L.) Brongn.)孢子壁的形成和发育进行了研究。结果表明, 水蕨孢子呈辐射对称, 三裂缝, 表面具肋条状纹饰。孢子壁由内壁、外壁和周壁三部分构成。在四分体阶段外壁已基本形成, 其外壁显著, 表面光滑, 质地均匀, 由孢粉素形成, 外壁厚约3-5 μm, 脊高约5-7 μm。周壁由绒毡层残余物在外壁表面沉积形成, 较薄, 厚度只有0.1 μm, 表面具有杆状突起。研究结果对揭示孢子纹饰和孢子壁各层的形成过程、来源和稳定性有一定的意义, 并为蕨类植物孢粉学和系统学研究提供基础资料。     

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。     

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。     

Morphology and ultrasctructure of spores Klukia tyganensis Krassilov (Schizaeaceae, Filicales) from the Berriassian of the Tyrma Depression (Russian Far East)

In situ spores of the fern Klukia tyganensis Krassil. from the coal-bearing deposits on the right bank of the Tyrma River (Berriassian, Bureya River Basin, Tyrma Depression) have been examined using light, scanning and transmission electron microscopy. The spores of K. tyganensis are demonstrated to be similar in the ultrastructure of sporoderm to that of some species of the extant genus Anemia and to differ from the spores of Lygodium in the ultrastructure of perispore and exospore.     

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。     

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。     

水蕨孢子壁的形成和发育

利用光镜、扫描电镜和透射电镜对水蕨科（Parkeriaceae）水蕨（Ceratopteris thalictroides（L．）Brongn．）孢子壁的形成和发育进行了研究。结果表明,水蕨孢子呈辐射对称,三裂缝,表面具肋条状纹饰。孢子壁由内壁、外壁和周壁三部分构成。在四分体阶段外壁已基本形成,其外壁显著,表面光滑,质地均匀,由孢粉素形成,外壁厚约3—5μm,脊高约5—7μm。周壁由绒毡层残余物在外壁表面沉积形成,较薄,厚度只有0．1μm,表面具有杆状突起。研究结果对揭示孢子纹饰和孢子壁各层的形成过程、来源和稳定性有一定的意义,并为蕨类植物孢粉学和系统学研究提供基础资料。     

Spore morphology and ultrastructure of Cyathea (Cyatheaceae,Pteridophyta) species from southern South America

Spore sculpture and wall structure of eight Cyathea (Cyatheaceae) species from southern South America were studied using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Two layers, i.e. an inner and an outer layer, were observed in the perispore. The inner layer has two strata: the inner stratum is attached to the exospore and composed of rodlets tangentially oriented to the spore surface and randomly intermixed; the outer stratum consists of a three-dimensional network of rodlets with either free or fused distal edges forming spinules. The outer layer is thin, darkly contrasted and covers the rodlets. In most cases, the exospore has two layers and a pitted surface. In Cyathea atrovirens, the exospore surface is smooth, while in C. delgadii and C. myriotricha it is verrucate. The homogeneity of perispore features within the genus Cyathea is evident, while exospore features are heterogeneous. The exospore has different kinds of surface-structures that are of potential interest for assessing evolutionary trends within the group.     

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。     

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。     

Ultrastructure of the spore in four Japanese species of Ptychomitrium Fürnr. (Musci)

The ultrastructure of the mature spore in four Japanese species of the acrocarpous moss genus Ptychomitrium is presented. In all species the spores have a similar pattern: there is no recognisable aperture nor sporoderm polarity, exine and perine are poorly developed, cytoplasm only occasionally shows polarity, and plastids have a well developed inner membrane system. The presence of frequent intine protrusions is a remarkable feature of this genus. A multilaminar structure of the exine, already observed in Grimmia, occurs also in these species although here it is less pronounced. The significance of these features is discussed within these species, as well as in comparison to other taxa, especially the genus Grimmia.     

The genus Saitobryum (Pottiaceae) revisited

The genus Saitobryum R.H.Zander comprises two species: S. lorentzii (Müll.Hal.) Ochyra distributed in Mexico and the Central Andes and Saitobryum pascoense M.J.Cano & J.A.Jiménez from the Central Andes of Peru, described here as new. The new species is distinguished from S. lorentzii by its upper and middle laminal cells papillose throughout, border of 2–3 rows of thick-walled and smooth cells, lamina usually with bistratose patches, and occasionally bistratose margins. The diagnostic characters of Saitobryum are re-evaluated and a key to the species of this genus is provided. Both species are described and illustrated. New localities for S. lorentzii and a map showing the complete distribution of this genus are given.     

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。     

Morphology and ultrastructure of modern and fossil spores in order Schizaeales schimp

The morphology and ultrastructure of modern and fossil spores were investigated using light, scanning, and transmission electron microscopes. We grouped spores into two groups according to ultrastructural features and sculptures of sporoderm: 1—exospore of Anemia and Klukia form the echini of sculpture; 2—exospore of Lygodium is smooth and perispore forms sculpture.     

Abnormal spore morphology and wall ultrastructure in Anemia tomentosa var. anthriscifolia and A. tomentosa var. tomentosa (Anemiaceae)

The spores of Anemia tomentosa var. anthriscifolia and A. tomentosa var. tomentosa were studied focusing the attention on their abnormalities. The study was based on fresh and herbarium material and the spores were examined with light, scanning and transmission electron microscopy. Normal, abnormal and abortive spores were observed in both taxa. The normal spores were trilete, triangular in polar view, and the ornamentation consisted of parallel ridges separated by narrow and smooth grooves. The spores were observed in monads, dyads, triads and tetrads. The abnormal spores were monolete, trilete, tetralete or alete with great variations in size. In fact, some spores were almost double the size of the normal ones. Some differences were also found in the ornamentation of the spores. Aborted and not completely developed spores were also observed in the specimens. The wall ultrastructure of the taxa was studied for the first time. The exospore was two-layered with numerous cavities inside its structure, and the perispore was also two-layered. The results revealed that the sporoderm ultrastructure of both normal and abnormal spores of the taxa analyzed was very similar.     

Palynological analysis of Cheilanthes Species (Adiantaceae-Pteridophyta) of Northwestern Argentina

The spores of seven Cheilanthes Sw. species that grow in the Northwest Region of Argentina were studied with LM, SEM and TEM.

They were: Cheilanthes margínala H. B. K., C. micropteris Sw., C. myriophylla Desv., C. notholaenoides (Desv.) Weath., C. pilosa Gold., C. poeppigiana Mett. ex Kuhn, and C. pruinata Kaulf.

C. volcanensis de la Sota, mentioned for the region, was not included because all the collected material was sterile or immature.

The equatorial diameter is not useful in distinguishing species because of the interspecific variability of such species as C. micropteris, C. poeppigiana and C. pruinata. In other cases interspecific variation overlaps.

All the species analysed here have one basic pattern of structure: a homogeneous, smooth exospore and a sculptured perispore.

The perispore has two layers: an innermost one, granular, compact and an outermost one, reticulate with or without an outer lamella. The outermost layer constitutes the greatest part of the perispore.

Five sculpture groups were distinguished: rugulose, ridged, cristate, cristate-reticulate and tridimensionally reticulate.

One new type of sculpture is mentioned in Cheilanthes: ridged.     

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.