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。     

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。     

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。     

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3-5 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。     

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。     

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。     

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。     

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。     

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。     

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.     

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.