四回毛枝蕨配子体发育的研究

采用MS培养基培养四回毛枝蕨孢子,利用光学显微镜详细观察记录了其孢子萌发、配子体发育及幼孢子体形成的整个过程。结果表明:成熟的孢子黑褐色,不透明,极面观圆球形,赤道面观蚕豆型,单裂缝,表面微褶皱。播种后8d左右萌发,萌发类型为书带蕨型,配子体发育为三叉蕨型。播种20d左右发育为片状体。播种30d左右形成幼原叶体,幼原叶体暂不对称,成熟原叶体呈蝴蝶形。原叶体边缘及背腹面都具毛状体,数量丰富,单细胞。播种50d左右开始有性器官出现,精子器近圆球形,由3细胞构成,成熟颈卵器颈部由5列细胞构成。原叶体受精后1月内可看到幼胚生成。     

Sexual differentiation in population of prothallia inLygodium japonicum

InLygodium japonicum, the archegonium was formed when the prothallium grew to approximately 1.5 mm in width irrespective of age, photoperiod, temperature or concentration of sucrose in the medium. Surgically cut prothallia produced archegonia only when the fragments regenerated to ca. 1 mm in width. Prothallia of smaller dimensions formed antheridia rather than archegonium, but only if archegoniated prothallia of the larger size coexisted in the population. Antheridiogens and inhibitors of archegonial differentiation became detectable by bioassay in conditioned media of 14-and 16-day-old prothallia, respectively, and continued to accumulate in the medium during culture in the light at 25 C. Twelve-day-old or younger prothallia are very sensitive to exogenously applied hormonal substances, whereas by day 14 the response had diminished.     

DIE WIRKUNG VON PHYTOHORMONEN AUF KEIMUNG UND ENTWICKLUNG VON FARNPROTHALLIEN IV. DIE WIRKUNG VON UNTERSCHIEDLICHEN GIBBERELLINE UND VON ALLO-GIBBERINSAURE AUF DIE AUSLOSUNG DER ANTHERIDIENBILDUNG BEI ANEMIA PHYLLITIDIS L. UND EINIGEN POLYPODIACEEN

The relative activities of seven gibberellins have been testedin their ability to induce antheridia in prothallia of Anemiaphyllitidis. The spectrum of activities differs from the spectradescribed for other gibberellin reactions. Allogibberic acidproved to be highly active in the Anemia test. Additionallyit causes a change in the polarity of the germinating spore.Under the influence of this compound the primary rhizoid istransformed into an additional chloronema. In high concentrationsof allogibberic acid more than 80% of the prothallia developinto those "twins". Out of the polypodiaceous ferns only fewspecies respond to gibberellin application. The relations between chemical structure and activity of differentgibberellins are discussed. (Received January 17, 1966; )     

北京地区蕨类植物区系分析

对北京地区蕨类植物区系进行了初步分析,研究表明,北京共有蕨类植物77种,隶属于19科34属,以蹄盖蕨科、岩蕨科、鳞毛蕨科、卷柏科等为优势科,以岩蕨属、卷柏属、铁角蕨属等为优势属,科内及属内分化程度较低,种类组成贫乏;地理成分以温带成分占优势,有11属为温带分布属,占非世界分布属总数的61．11％,除世界种和中国特有种外,全为温带性质的种;生境特点以石生为主,大多数种类分布在北京西部和北部的山区;与河北的关系最为密切,其次为山西、内蒙、辽宁、山东,与秦岭也有一定的联系,与西藏的关系疏远。     

蹄盖蕨科的系统发育: 叶绿体DNA trnL-F区序列证据

蹄盖蕨科Athyriaceae是蕨类植物中一个复杂的大科,由于属间关系不甚清楚,该科分类系统还有一些问题,比如新蹄盖蕨、拟鳞毛蕨属、假冷蕨属、肠蕨属、短肠蕨属和菜蕨属的系统位置常有争议。根据蹄盖蕨科34种植物和3种外类群植物的叶绿体DNA trnL-F区序列建立了系统发育树,结果显示:1.trnL_F区序列分析的结果与rbcL基因序列分析的结果几乎一致。2.新蹄盖蕨属Neoathyrium Ching&Z.R.Wang不应成立,该属应与角蕨属Cornopteris Nakai合并。3.假冷蕨属Pseudo     

岩蕨科、球盖蕨科的系统位置：叶绿体DNAtrnL-F区序列证据

岩蕨科(Woodsiaceae)和球盖蕨科(Peranemaceae)历来被多数学者认为是亲缘关系密切的两个科,它们的系统位置一直存在争议,两科曾被放入三叉蕨科(Aspidiaceae)、碗蕨科(Dennstaedtiaceae)、鳞毛蕨亚科(Dryopteridoidaae)及鳞毛蕨科(Dryopteriaceae)蹄盖蕨亚科(Athyrioideae)中。根据岩蕨科1种、球盖蕨科3种、蹄盖蕨科8种、鳞毛蕨科2种及1种外类群假大羽铁角蕨(Asplenium pseudolaserpitiifolium)的cpDNA基因trnL-F区序列建立的系统树,结果显示,岩蕨科和球盖蕨科的亲缘关系较远,岩蕨科与蹄盖蕨科有密切的亲缘关系,球盖蕨科与鳞毛蕨科亲缘关系较近,岩蕨科和球盖蕨科是处于不同进化线上的植物。秦仁昌（1978）和Pichi-Sermolii（1977）的系统将二者分别作为独立的科是合适的。     

Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification

The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL–F) and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I), Cheilanthopsis–Protowoodsia (clade II) and Woodsia s.s. (clade III). In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.     

Morphogenesis of the sexual phase of six Mexican species of the Dryopteris (Dryopteridaceae), Part II]

The development of the sexual phase of six Mexican species of Dryopteris is described and compared. Spores of all studied species are monolete, ellipsoid and have a rugose surface; the perine is folded, brown to dark brown, with a tubercled outline. Germination pattern is of the Vittaria-type and the development pattern of the prothallia is of the Aspidium-type. Gametangia are of the common type for the leptosporangiate advanced ferns. First leaves of the sporophytes appear 258-265 after sowing and apparently in Dryopteris pseudo-filix-mas the sporophyte have an apogamic origin (80 days). To make a comparative analysis of gametophytic characteristics in the twelve Mexican species and conclude of germination is of the Vittaria-type and development pattern prothallial is of the Aspidium-type, and unicelular trichomes on margin and superficial gametophytic to yield irregular aspect are characteristics to yield unit and characteristic to genera to conform Dryopteridaceae family (sensu Moran 1995) with the exception of Didymochlaena genus.     

The role of asymmetric cell division in pteridophyte cell differentiation. I. Localized metal accumulation and differentiation inVittaria gemmae andOnoclea prothallia

Summary In gemmae ofVittaria graminifolia and prothallia ofOnoclea sensibilis, cell differentiation is initiated by nuclear migration and geometrically asymmetric cell division. The small daughter cells inVittaria develop into antheridia in the presence of gibberellic acid or into rhizoids or new prothallia in its absence. Antheridial differentiation from asymmetric division is induced inOnoclea byPteridium antheridiogen, whereas rhizoid or vegetative cell formation occurs in its absence. Although asymmetric cytokinesis initiates differentiation, it does not in itself determine the developmental fate of the smaller cell. Several histochemical techniques demonstrate that prior to nuclear migration and cell division, Ca²⁺ accumulates in the cytoplasm and wall of the cell at the site where asymmetric division will occur, regardless of the developmental fate of the small cell. The cytoplasmic localization of Ca²⁺ appears to reflect a mobilization of Ca²⁺ from within the cell that eventually moves into the cell wall. We propose that this internal accumulation of Ca²⁺ leads to a localized decrease in cytosolic [Ca²⁺] which in turn may regulate developmental events such as nuclear migration.Publishing prior to 1984 as Alix R. Bassel.     

东北蕨类植物配子体发育的研究X.岩蕨科

在室内培养条件下,详尽地比较观察了我国东北产的岩蕨科２属４种的配子体发育过程,了解该科在配子体发育上的特征,来说明建立岩蕨科的合理性和种属间的区别。     

Variation in anther and pollen morphology in Leucaena Benth. (Leguminosae-Mimosoideae)

Variation in anther and pollen morphology is described and illustrated for species of Leucaena and a selection of species from closely related genera. This is discussed in relation to the variation found in the closely related genera of the informal Leucaena, Dichrostachys and Xylia groups of the tribe Mimoseae. A number of characters for cladistic analysis are identified and putative homologies assessed. Preliminary taxonomic conclusions about the status and relationships of L. multicapitula are discussed. Mode of anther dehiscence is also described and illustrated. The observation of persistent intact tapetal membranes after anther dehiscence in some species of Leucaena is discussed in relation to pollen unit.     

GA3 content in young and mature antheridia of Chara tomentosa estimated by capillary electrophoresis

The content of gibberellic acid (GA3) in male sex organs of Chara tomentosa L. was estimated using capillary electrophoresis. Young antheridia contained 0.25 microg GA3 while mature ones 0.48 microg per antheridium. Although there are significant differences in GA3 content in antheridia between C. vulgaris and C. tomentosa, these values calculated per one spermatid are 2.4 and 3.3 pg, respectively. The present results compiled with the previous knowledge about regulation of GA3-dependent development of Characeae species allow an implication that the mechanisms controlling antheridia differentiation in both species can be similar.     

Studies on the Chinese Woodsiaceae (3)—Phylogeny and Speciation

The history of the study on the woodsiodes is briefly surveyed in the paper. The family Woodsiaceae is recognized by the present author. The relationships among the species and the probable evolution of the family are discussed based on author's cytological and comparative morphological studies, and are indicated by Wagner's method, with numerical values as the indices. Woodsiaceae may have originated from the common ancestor of modern Dicranopteris and Sticherus of Gleicheniaceae, and evolved from it into two main branches, i.e., Woodsia and Protowoodsia. The origin of species through polyploid series are discussed, and W. andersonii, W. subcordata, W. alpina and Cheilanthopsis indosiosa considered as fertile allopolyploids; the probable way of speciation is also suggested for these species.     

<Emphasis Type="Italic">Saprolegnia brachydanis</Emphasis>, A New Oomycete Isolated from Zebra Fish

Saprolegnia brachydanis is described from zebra fish (Brachydanio rerio) in Wuhan, Hubei Province, China. The species is illustrated and compared with other species of the genus. The distinctive characteristics of S. brachydanis are the production of glomerulate oogonia wrapped around by predominantly monoclinous antheridia which can be up to eight in one oogonium. The oogonial stalks are short, straight, or curved and the antheridia, twisted, can enwind one or more oogonia. The oospores cannot mature or easily abort. Morphological features of the oomycete and the ITS sequence of its rDNA as well as the comparison with related species are discussed in this article.     

Antheridiogen production and response in Polypodiaceae species

Antheridiogen chemicals secreted by living fern gametophytes have been shown to influence production of male gametangia and thus mating systems in a large number of terrestrial fern species. Antheridiogens have not previously been thought to be prevalent in the Polypodiaceae, a large family composed mostly of tropical epiphytes. This study presents bioassay methods more sensitive than previously used to detect antheridiogen and demonstrates that antheridiogens are also operative in the Polypodiaceae and in epiphytic species. Seven species in six genera (Campyloneurum angustifolium, C. phyllitidis, Lepisorus thunbergianus, Microgramma heterophylla, Phlebodium aureum, Phymatosorus scolopendria, and Polypodium pellucidum) were tested for the presence of an antheridiogen system. All species tested except P. aureum were induced to produce antheridia precociously by their own antheridiogen and by that of Pteridium aquilinum (APt). Phlebodium aureum responded to APt and promoted antheridium formation in Onoclea sensibilis but did not respond to its own antheridiogen. Spores of all species except P. aureum were induced to germinate in darkness by antheridiogen of the same species and by APt and to form antheridia in the dark, further enhancing the possibility of intergametophytic mating.     

Comparative morphology and development of inflorescence adnation in rattan palms

The morphology and development of inflorescences in 14 genera and 52 species of rattans and related genera of Lepidocaryoid palms were examined. Inflorescences are free (not adnate) in Ancistrophyllum, Eremospatha and Oncocalamus. Adnation between the inflorescence and internode above occurs in Korthalsia, Myrialepis, Plectocomia and Plectocomiopsis. Adnation between the inflorescence and both the internode and leaf sheath above occurs in Calamus, Calospatha, Ceratolobus and Daemonorops. This leaf-borne, but initially axillary, bud is displaced on to the base of the next younger leaf primordium by the second plastochrone. Later elongation of the internode further separates the inflorescence from its original node. Stages of initiation and early development of adnate buds are illustrated for ten species. Vegetative buds of some Calamus species develop like inflorescence buds. However, other species have unusual bud positions which cannot be interpreted at present. The degree of inflorescence adnation tends to be greater in presumably specialized species than in unspecialized ones.     

ITS region of the rDNA of Pythium longandrum, a new species; its taxonomy and its comparison with related species

Pythium longandrum (F-73.0) was isolated, from soil samples taken in Lille in northern France. Morphologically the fungus resembles closely Pythium rostratum, however its antheridial characters are unique. The oogonia of this species are provided with hypogynous and monoclinous antheridia. The antheridial cells are inflated and are probably the largest and longest for the genus. The internal transcribed spacer region of its nuclear ribosomal DNA indicates that it is entirely different from all other species of Pythium. This new species is characterized by its spherical to elongated sporangia, smooth-walled oogonia and hypogynous to monoclinous antheridia bearing long antheridial cells closely applied to the oogonia. Morphological features of this new species, together with the sequences of the ITS region of its nuclear ribosomal DNA and comparison with related species are discussed here.     

Dehiscence of antheridia in thelypteroid ferns

The manner of antheridial opening was investigated in 18 species of the family Thelypteridaceae by scanning electron microscopy. Four different types have been observed: 1) An irregular rupture in the cap cell wall. 2) A rounded opening like a pore. 3) The cap cell being totally thrown off. 4) Opening at one side like a lid, with the cap cell still being attached to the ring cell on the opposite side. Although it has been claimed that the manner of dehiscence is specific to different species, no evidence for this view was found. In 9 of the 18 species studied at least two manners of opening occurred. In 7 of the 18, three or four occurred. In the majority of cases male gametes are in the spermatid stage at time of release from the antheridium. Later on the slimed cell wall dissolves and the spermatozoids are liberated. In a few cases this process is more or less completed within the antheridia, so that spermatozoids are mature already at the time of release.     

SEED PRODUCTION AND DISPERSAL IN DALECHAMPIA (EUPHORBIACEAE): DIVERGENT PATTERNS AND ECOLOGICAL CONSEQUENCES

Patterns of capsule development and methods of seed dispersal are described and compared for 16 neotropical species of Dalechampia. In 15 species all the capsules in a single inflorescence develop simultaneously. In one species, D. spathulata, the capsules develop sequentially. I suggest that the difference between D. spathulata and the other species is the result of the fact that D. spathulata occurs in a low-light, rainforest environment, whereas the other species grow in high-light environments. Sequential development of capsules appears to reduce the loss of seeds to seed predators in species that occur in light-limited environments. The seeds of all 16 species of Dalechampia are dispersed by explosive dehiscence of the capsules. Within the genus there are several different adaptations that increase the average dispersal distance for the seed crop.