Spore morphology of pteridophytes from China Ⅱ. Sinopteridaceae

Spores of 61 species and 6 varieties in 9 genera of the Sinopteridaceae were examined under scanning electron microscope (SEM). Based on surface ornamentation and other features, the spores of the Sinopteridaceae are divided into three types. In type Ⅰ , the exospore is smooth and the surface ornamentation, which is reticulate, cristate, echinate or rugate, is formed by the perispore. All the other genera of this family, except for Onychium and Cryptogramma, have this pattern of spores. In type Ⅱ, the surface ornamentation is formed by both perispore and exospore. This pattern is found only in Cryptogramma. In type Ⅲ, the perispore is thin and the surface ornamentation is formed by the exospore. Onychium is characterized by this type of spores. Those genera with spores of type Ⅰ of the Sinopteridaceae seem to be closely related to each other and should be natural members of this family. The systematic position of Cryptogramma and Onychium, with spores of type Ⅱ and type Ⅲ respectively, however, should be reconsidered. Aleuritopteris might be the mostprimitive member of the Sinopteridaceae from the evidence of spore morph     

中国蕨类植物孢子形态的研究 Ⅱ. 中国蕨科

利用扫描电镜对国产中国蕨科Sinopteridaceae植物9属61种6变种的孢子进行了观察。结果表明,该科植物的孢子可分为3种类型：(1)孢子球形,三裂缝;周壁较厚,疏松地包在孢子之外;外壁光滑,表面纹饰由周壁形成,呈网状、嵴状、刺状或皱状。除金粉蕨属Onychium和珠蕨属Cryptogramma外,该科其他属的植物都具此类型孢子。(2)孢子钝三角形,三裂缝;周壁较薄,由周壁和外壁共同形成表面轮廓,表面具疣状或颗粒状纹饰。具此类型孢子的只有珠蕨属。(3)孢子钝三角形,三裂缝,沿裂缝两侧各有一脊状隆起或瘤状纹饰;周壁薄,由外壁形成表面纹饰的基本轮廓;具赤道环、近极脊和远极脊。具此类型孢子的只有金粉蕨属。另外,从孢粉学的角度对该科的分类和系统演化进行了探讨。     

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。     

THE SPORE PATTERN IN SOME SPECIES OF CHEILANTHES

Of the 32 taxa examined, 13 contained 32 spores in each sporangium and are considered apo-gamous, 14 were sexual species with 64 spores per sporangium, and 5 had 32 spores in some sporangia and 64 in others. When considered as a whole, the spores ranged in size from 29.9 to 74.88μ. Most species had oval or globose spores but several had tetrahedral spores. The spores of all were radially symmetrical. Almost all of the species possessed a crassimarginate type of laesura and all except C. cooperae and C. viscida had a perispore. The ornamentation of the perispore showed the following patterns: napate, granulate, psilate, lobate, foveate, and echinate. The exine pattern was predominantly psilate but foveate, rugulate, napate, and granulate conditions were observed. Seventeen taxa were found to have some degree of spore abortion.     

Spores morphology and synangia in neotropical fern species of Marattia (Marattiaceae)

The Marattiaceae are represented by a small family of four to six genera that bear esporogenous structures of two types: sorus with free eusporangia in Angiopteris and Archangiopteris, and indurated synangium in Christensenia, Danaea and Marattia. Marattia is a pantropical genus of about eight to ten species in the paleotropic and seven to eight species in the neotropic. In order to describe the spores and sinangia morphology, this study analyzed the shape of the receptacles, and the position of the synangia, and evaluated the spores with SEM, of seven neotropical species of the genus Marattia: M. alata, M. cicutifolia, M. excavata, M. interposita, M. laevis, M. laxa y M. weinmanniifolia from several collections. The receptacles were fully developed in M. cicutifolia and M. laevis, and scarcely overelevated in the rest of the species. The synangium was ellipsoidal and had intramarginal to supramedial position in the laminae. The spores of Marattia were elliptic. Among the taxa, only monolete spores were found, with no trilete, aborted or deformed spores. The laesura was linear and reached about two of the total length of the spore. The perispore appears as a continuous thin layer deposited on the exospore according to its ornamentation in M. cicutifolia and M. laevis. It is smooth in M. alata, rugate in M. excavata and pustulate-rugate in two species: M. interposita and M. laxa. The exospore is echinate in M. cicutifolia and M. laevis and pustulate in the other species. In M. weinmannifolia spores produced by the same sinangium may have different ornamentation types. We concluded that, while the presence of ellipsoidal and superficial synangia and monolete spores aperture were generic traits, the micro and macro-ornamentation types of the perispores and exospores vary at specific level. Besides, macro-ornamentation can be bulliform (pustulate), a combination of bulliform and muriform types (pustulate-rugate), muriform (rugate-retate) and stelliform (echinate); finally, granular micro-ornamentation can be seen frecuently in perispores.     

The spores of Pteris cretica complex (Pteridaceae-Pteridophyta) in America

Spore morphology in the Pteris cretica complex, including Pteris brasiliensis, P. ciliaris, P. cretica, P. denticulata var. denticulata, P. denticulata var. tristicula, P. ensiformis, P. multifida and P. mutilata was examined using light and scanning electron microscope. The spores are trilete, triangular to circular in shape, with an equatorial thickening (= cingulum). Equatorial diameter ranges from 29 to 69 μm, and polar diameter from 18 to 53 μm. Exospore is proximally verrucate and distally rugate, with the exception of Pteris ensiformis, which has cones on both polar faces. Perispore is generally less than 1 μm thick, apparently single-layered in section, and translucent under light microscope. Spheroids were frequently observed on the surfaces of both perispore and exospore. Hyaline spores lacking cingulum were found in all specimens. Pteris brasiliensis, P. cretica and P. denticulata exhibit pronounced polymorphism and, in addition to trilete spores these taxa also produce atypical spores such as tetralete, monolete and intermediate types.     

Spore morphology and wall ultrastructure of Trachypteris species (Pteridaceae)

Trachypteris is a small genus consisting of four species native to America and Madagascar: Trachypteris induta, T.?pinnata, T.?gilliana, and T.?drakeana. The spores of the genus were studied using light microscopy and scanning and transmission electron microscopy. They are trilete, triangular to globose, with equatorial diameter of 29?C58???m and polar diameter of 26?C53???m. The exospore is 0.5?C1.1???m thick, plane, and two-layered. The perispore is 0.3?C6.8???m thick and two-layered. Depending on the species, two different ornamentations were observed: cristated with partially fused cristae, and ridged with partially fused ridges, forming an incomplete reticulum. Globules immersed in the perispore were occasionally observed. The systematic value of the Trachypteris spores is discussed, and their morphology and ultrastructure are compared with those of other related cheilanthoid ferns. The palynological characteristics presented here may be useful for phylogenetic studies within the Pteridaceae, and particularly within the cheilanthoid ferns.     

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.     

Spore morphology of the north Asian members of Cystopteridaceae

Spores of Cystopteridaceae from northern Asia were examined using scanning electron microscopy. To evaluate the utility of spore morphology in the taxonomy of each genus, we examined spores of 14 species: seven species each of Gymnocarpium and Cystopteris. Among these are 12 species occurring in northern Asia and two species from other regions for comparative studies. The study focused particularly on perispore characters and spore size. Spores of all species examined are monolete, bean-shaped, with a range in spore size of 26–56 × 18–37 μm for Cystopteris and 25–48 × 16–34 μm for Gymnocarpium. The perispore is morphologically diverse within Cystopteris, but less so within Gymnocarpium. The perispore of the Cystopteris spores is characterised by folds and spines that are separate or form complex sculptural elements. Sacci, ridges and flanges, sometimes on the same spore, are characteristic of the perispore of Gymnocarpium. Spores have straight laesura over which the perispore forms a crest. The crest represents a high and flat fold, which is entire, foveolate or reticulate.     

Spore abortion index (SAI) as a promising tool of evaluation of spore fitness in ferns: an insight into sexual and apomictic species

Ferns reproduce through small and usually haploid spores. The general paradigm states that whereas species produce good shaped spores, hybrids are sterile and form aborted spores. Apomictic fern species represent an unusual case, and it is believed that they produce an unbalanced spore spectrum. Until now, no comprehensive comparison of sexual and apomictic taxa using extensive spore fitness data has been published. Based on a representative data set of 109 plants from 23 fern taxa, we accomplished the first robust analysis of spore fitness using spore abortion index (SAI), the ratio of aborted to all examined spores. One thousand spores were analyzed for each plant. Focusing mainly on two major European fern taxa (Asplenium, Dryopteris), we compared this trait for different fern reproductive types (sexual/apomicts/hybrids) and ploidy levels (diploid versus polyploid). Our results confirmed the general assumption that shows higher SAI for apomictic taxa (18%) when compared to sexual taxa (3%). Furthermore, hybrids are characterized by having almost all spores aborted (99.8%) with the notable exception of pentaploid Dryopteris × critica (93.1%), the hybrid between sexual and apomictic taxa. We found no significant difference in SAI between sexual taxa of various ploidy levels or between sexual taxa of genera Dryopteris and Asplenium. Additionally, we carried out an optimization of the SAI method, outlying important guidelines for the use of this method in the future.     

Phylogenetics of Chinese Dryopteris (Dryopteridaceae) based on the chloroplast rps4-trnS sequence data

Dryopteris is one of the largest and most taxonomically complex fern genera in the Dryopteridaceae, with 127 species occurring throughout temperate, sub-temperate, subtropical, and tropical China. Investigations of the evolutionary relationships of a subset of these Chinese Dryopteris species, using DNA sequence-based methods, specifically tested the monophyly of the genus and the validity of the previous subgeneric classifications. Sixty species of Dryopteris, four closely related non-Dryopteris and three species of Arachniodes, were used as outgroup taxa. The rps4-trnS region of the chloroplast genome was sequenced in these species for the first time. Both maximum parsimony (MP) and neighbor-joining (NJ) analyses identified six polyphyletic clades that contained Dryopteris species. These results were supported by a Bayesian analysis of the same data set. The phylogenetic patterns strongly suggest the polyphyletic status of Dryopteris; the monophyletic groupings of the species do not correspond with either Fraser-Jenkins [In: Bull Brit Mus (Nat Hist) Bot 14(3):183–218, 1986} or Wu (In: Flora Reipublica Popularis Sinicae Tomus 5 (1) pp 1–241, 2000] subgeneric classification of Dryopteris, except in a few specific cases. This work represents the first molecular systematic analyses of Chinese Dryopteris, and we propose the next steps necessary to recognize new subgenera of the genus.     

Relationships and origins of the Dryopteris varia (L.) Kuntze species complex (Dryopteridaceae) in Korea inferred from nuclear and chloroplast DNA sequences

The Dryopteris varia species complex belongs to D. subg. Erythrovariae sect. Variae and includes eight closely related, controversial species. In Korea, six species belong to the complex; D. varia s. str., Dryopteris pacifica, Dryopteris sacrosancta, Dryopteris bissetiana, Dryopteris saxifraga, and Dryopteris saxifragivaria. The morphology of these species is highly variable due to the frequent occurrence of agamospory, hybridization, and/or polyploidization. We analyzed sequences of the nDNA pgiC and cpDNA rbcL, trnL–trnF IGS and atpF–atpH IGS regions from all six of these species to elucidate their relationships and origins, and to investigate the parentage of the putative hybrid taxon, D. saxifragivaria. Fourteen nDNA pgiC haplotypes and five cpDNA haplotypes were obtained from accessions of the D. varia complex in Korea. In particular, all accessions examined appear to have multiple pgiC haplotypes. Maximum parsimony and Bayesian inference analyses of the nDNA and cpDNA sequence data show that the agamosporous triploids D. sacrosancta and D. pacifica are of allopolyploid origin involving interspecific hybridization. The results also indicate that agamosporous triploid individuals of D. saxifragivaria in Korea were derived from hybridization between sexual diploid individuals of D. saxifraga (maternal) and agamosporous diploid individuals of D. bissetiana (paternal). In addition, our results strongly suggest that the agamosporous triploid D. varia s. str. is probably of autopolyploid origin, and cytoplasmic gene flow has occurred from D. sacrosancta to Dryopteris chinensis of D. subg. Dryopteris.     

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。     

Pollen morphology and its taxonomic significance in the tribe Gochnatieae (Compositae, Gochnatioideae)

In the context of recent molecular phylogenies of the basal grades of Compositae, we investigated the utility of pollen morphology within the tribe Gochnatieae. The pollen of 64 species of Anastraphia, Cnicothamnus, Cyclolepis, Gochnatia, Pentaphorus, and Richterago was studied using light microscopy and scanning electron microscopy. In addition, three extra-Gochnatieae genera (Ianthopappus, Leucomeris, and Nouelia) were examined as they were traditionally morphologically related to members of the tribe Gochnatieae. Three of the species of Gochnatieae were examined using transmission electron microscopy. Two pollen types, and two new subtypes, have been recognized on the basis of the pollen shape, size, and exine sculpture. The pollen features of Gochnatia sect. Moquiniastrum and G. cordata are similar and distinctive within the genus and support the recently re-circumscribed section Hedraiophyllum. Within the species with echinate pollen surface, the distinctive spine length of Anastraphia supports its recent resurrection as a genus. The identity of Pentaphorus could not be supported by pollen features as was for other morphological characteristics. The pollen features shared across Cyclolepis, Ianthopappus, Leucomeris, Nouelia and Gochnatia sect. Moquiniastrum, as well as those shared by Richterago and Anastraphia could be a result of parallel evolution.     

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。     

江西石松类孢子形态的研究

应用扫描电子显微镜对江西产２科５属８种（含变型）石松类植物的孢子形态进行了观察,结果表明,２科植物孢子形态相似,但外壁纹饰有差别,所观察的各属间、种间在孢子形态上亦有差异。     

SPORE MORPHOLOGY IN THE GENUS BRUCHIA SCHWAEGR. (MUSCI)

Scanning electron microscopy observations of the spores of Bruchia have resulted in the recognition of four spore types based on the ornamentation of the distal spore surface: warty or verrucate, pitted, reticulate, and spinose. The proximal surface of the spores of all species, except B. brevipes, is characterized by a central aperture region surrounded by a triangular murus or rows of spinae forming a triangle and 1 or 2 smooth or verrucate collars. The ornamentation patterns observed are considered to be characteristic for the genus. Spore morphology alone can rarely be used to distinguish species but in conjunction with certain other characteristics, it is an important taxonomic feature. Spore morphology is a major characteristic used to define the limits of the highly variable species B. flexuosa (spinose spores) and to distinguish it from the closely related species B. texana (reticulate spores). Variations in ornamentation patterns within the genus support the recognition of two subgenera (subgenus Bruchia and subgenus Sporledera). Spore morphology also supports the close relationship between Bruchia and Trematodon and is sufficient to eliminate several questionable taxa from the genus.     

Chemotaxonomic studies onArachniodes (dryopteridaceae) I. Phloroglucinol derivatives of japanese species

Twelve species ofArachniodes from Japan were examined for phloroglucinol derivatives and glandularity of rhizome and petiole bases. For comparison 3 species ofDryopteris, 1 species ofCtenitis, 4 species ofPolystichum, and 1 species ofAcystopteris were also investigated. Phloroglucinol derivatives were detected for the first time by sensitive TLC in the followingArachniodes, Dryopteris andPolystichum species:A. amabilis, A. dimorphophylla, A. exilis, A. hasseltii, A. maximowiczii, A. miqueliana, A. mutica, A. nipponica, A. okinawensis, A. simplicior incl. var.major, D. hayatae, D. sparsa, andP. tsus-simense. On the other hand,A. pseudo-aristata, A. standishii, P. polyblepharum, P. pseudomakinoi, P. retroso-paleaceum, Ctenitis maximowicziana, andAcystopteris japonica were totally lacking phloroglucinols. The phloroglucinol containing species ofArachniodes andPolystichum contained external glands, whereas those ofDryopteris contained internal and/or external glands. External glands are common inDryopteris sect. Nephrocystis. In taxa lacking phloroglucinols no glands were present. The homologous iso-aspidins BB and AB were detected in ferns for the first time.     

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.