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Sample records for fern ceratopteris thalictroides

  1. Development of microsatellite markers in the tetraploid fern Ceratopteris thalictroides (Parkeriaceae) using RAD tag sequencing.

    Science.gov (United States)

    Yang, X Y; Long, Z C; Gichira, A W; Guo, Y H; Wang, Q F; Chen, J M

    2016-02-19

    To understand the genetic variability of the tetraploid fern Ceratopteris thalictroides (Parkeriaceae), we described 30 polymorphic microsatellite markers obtained using the restriction site-associated DNA (RAD) tag sequencing technique. A total of 26 individuals were genotyped for each marker. The number of alleles per locus ranged from 4 to 10, and the expected heterozygosity and the Shannon-Wiener index ranged from 0.264 to 0.852 and 0.676 to 2.032, respectively. Because these 30 microsatellite markers exhibit high degrees of genetic variation, they will be useful tools for studying the adaptive genetic variation and sustainable conservation of C. thalictroides.

  2. Stable transformation of ferns using spores as targets: Pteris vittata and Ceratopteris thalictroides.

    Science.gov (United States)

    Muthukumar, Balasubramaniam; Joyce, Blake L; Elless, Mark P; Stewart, C Neal

    2013-10-01

    Ferns (Pteridophyta) are very important members of the plant kingdom that lag behind other taxa with regards to our understanding of their genetics, genomics, and molecular biology. We report here, to our knowledge, the first instance of stable transformation of fern with recovery of transgenic sporophytes. Spores of the arsenic hyperaccumulating fern Pteris vittata and tetraploid 'C-fern Express' (Ceratopteris thalictroides) were stably transformed by Agrobacterium tumefaciens with constructs containing the P. vittata actin promoter driving a GUSPlus reporter gene. Reporter gene expression assays were performed on multiple tissues and growth stages of gametophytes and sporophytes. Southern-blot analysis confirmed stable transgene integration in recovered sporophytes and also confirmed that no plasmid from A. tumefaciens was present in the sporophyte tissues. We recovered seven independent transformants of P. vittata and four independent C. thalictroides transgenics. Inheritance analyses using β-glucuronidase (GUS) histochemical staining revealed that the GUS transgene was stably expressed in second generation C. thalictroides sporophytic tissues. In an independent experiment, the gusA gene that was driven by the 2× Cauliflower mosaic virus 35S promoter was bombarded into P. vittata spores using biolistics, in which putatively stable transgenic gametophytes were recovered. Transformation procedures required no tissue culture or selectable marker genes. However, we did attempt to use hygromycin selection, which was ineffective for recovering transgenic ferns. This simple stable transformation method should help facilitate functional genomics studies in ferns.

  3. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.; Devi, S. (National Botanical Research Institute, Lucknow (India))

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  4. A Mutant Hunt Using the C-Fern (Ceratopteris Richardii)

    Science.gov (United States)

    Calie, Patrick J.

    2005-01-01

    A modification of the popular C-Fern system, the tropical fern Ceratopteris richardii is developed in which students plate out a genetically mixed set of fern spores and then select for specific mutants. This exercise can provide students with an experience in plant mutant selection and can be used as a platform to expose students to a diverse…

  5. High-efficiency stable transformation of the model fern species Ceratopteris richardii via microparticle bombardment.

    Science.gov (United States)

    Plackett, Andrew R G; Huang, Liandong; Sanders, Heather L; Langdale, Jane A

    2014-05-01

    Ferns represent the most closely related extant lineage to seed plants. The aquatic fern Ceratopteris richardii has been subject to research for a considerable period of time, but analyses of the genetic programs underpinning developmental processes have been hampered by a large genome size, a lack of available mutants, and an inability to create stable transgenic lines. In this paper, we report a protocol for efficient stable genetic transformation of C. richardii and a closely related species Ceratopteris thalictroides using microparticle bombardment. Indeterminate callus was generated and maintained from the sporophytes of both species using cytokinin treatment. In proof-of-principle experiments, a 35S::β-glucuronidase (GUS) expression cassette was introduced into callus cells via tungsten microparticles, and stable transformants were selected via a linked hygromycin B resistance marker. The presence of the transgene in regenerated plants and in subsequent generations was validated using DNA-blot analysis, reverse transcription-polymerase chain reaction, and GUS staining. GUS staining patterns in most vegetative tissues corresponded with constitutive gene expression. The protocol described in this paper yields transformation efficiencies far greater than those previously published and represents a significant step toward the establishment of a tractable fern genetic model.

  6. Ultrastructure of the Mature Egg and Fertilization in the Fern Ceratopteris thafictroides

    Institute of Scientific and Technical Information of China (English)

    Jian-Guo Cao; Nai-Ying Yang; Quan-Xi Wang

    2009-01-01

    The ultrastructure of the mature egg and fertilization in the fern Ceratopteris thalictroides (L.) Brongn. were observed by transmission electron microscopy. The results revealed that the mature egg possesses an obvious egg membrane at the periphery of the egg. Furthermore, a fertilization pore was identified in the upper egg membrane of the mature egg. The structure of the pore is described for the first time. The fertilization experiment indicated that spermatozoids crowd into the cavity above the egg through the neck canal of the archegonium; however, only one of these can penetrate into the egg through the fertilization pore. Immediately on penetration of the spermatozoid, the egg begins to shrink. The volume of the fertilized egg decreases to almost one-half that of the unfertilized egg. As a result, the protoplasm of the fertilized egg becomes dense and opaque, which may lead to a situation where the organelles of both the egg and the fertilizing spermatozoid become indistinguishable. Simultaneously, abundant vesicles containing concentric membranes or opaque materials appear near the fertilization pore in the cytoplasm of the fertilized egg. These vesicles are considered to act as a barrier that prevents polyspermy. The present study provides a new insight into the ultrastructure of the mature egg and the cytological mechanism of fertilization in ferns.

  7. Effects of ecological factors on growth of Ceratopteris thalictroides%生态因子对水蕨生长的影响

    Institute of Scientific and Technical Information of China (English)

    陈蔚辉; 刘俊祥

    2009-01-01

    通过移植和孢子繁殖试验,研究了生态因子对粤东地区水蕨生长的影响,结果表明,水蕨生长具有季节性变化,4-6月是水蕨生长高峰期,6月和12月开始形成孢子;水蕨孢子萌发和孢子体的发育均需要光照;光照4~10 h,水蕨孢子的成苗率显著提高,最高达82.4%;遮荫对水蕨叶柄基部直径、植株鲜重和干重有显著的抑制作用,导致叶柄纤细,易倒伏;光照显著促进水蕨叶的生长,使其抗伏性增强,并加速其孢子囊的成熟;基质(塘泥+河沙,其体积比为 4:1)培养能提高水蕨幼苗的成活率,促进水蕨孢子体的生长发育.%Effects of ecological factors on growth habit of Ceratopteris thalictroides in easten Guangdong was studied by experiments of transplantation and spore reproduction. Result showed that: there were seasonal changes in the growth of C. Thalictroides , its growth peak was from April to June , and spore began to form spore in June and December. Both germination of the spore and development of the sporophyte need light. Ratio of the spore germination of conspicuously increased when exposed to light for 4~10 hours, with its highest ratio up to 82.4% . Shadow significantly inhabited diameter of the petiole , decreased its wet weight and its dry weight, induced its thin petioles and lodge easily . While the light conspicuously increased the growth of C. Thalictroides, it also enhanced its antilodging and accelerated maturity of its sporangium . The survival ratio of seeding and growth of C. Thalictroides conspicuously increased in soil of pond mud and sand (bulk ratio 4:).

  8. A fern AINTEGUMENTA gene mirrors BABY BOOM in promoting apogamy in Ceratopteris richardii.

    Science.gov (United States)

    Bui, Linh T; Pandzic, Dzevida; Youngstrom, Christopher E; Wallace, Simon; Irish, Erin E; Szövényi, Péter; Cheng, Chi-Lien

    2017-04-01

    Asexual reproduction is widespread in land plants, including ferns where 10% of all species are obligate asexuals. In these ferns, apogamous sporophytes are generated directly from gametophytes, bypassing fertilization. In the model fern Ceratopteris richardii, a sexual species, apogamy can be induced by culture on high sugar media. BABY BOOM (BBM) genes in angiosperms are known to promote somatic embryogenesis, which like apogamy produce sporophytes without fertilization. Here, a Brassica napus BBM (BnBBM) was used to investigate genetic similarity between apogamy in ferns and somatic embryogenesis in angiosperms. A C. richardii transcriptome was constructed from which one AINTEGUMENTA-LIKE unigene, CrANT, was identified. Whole mount in situ hybridization showed that CrANT is expressed in sperm and fertilized eggs. Phylogenetic analysis grouped CrANT with other non-seed-plant ANT genes to the euANT clade but in a branch separate from BBM genes. Overexpression of CrANT or BnBBM promotes apogamy in C. richardii without sugar supplement. CrANT knockdown gametophytes responded weakly to sugar for apogamy promotion. Theses results suggest some genetic conservation between apogamy and somatic embryogenesis and that such asexual reproduction may be ancient. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  9. Influence of gravity and light on the developmental polarity of Ceratopteris richardii fern spores

    Science.gov (United States)

    Edwards, E. S.; Roux, S. J.

    1998-01-01

    The polarity of germinating single-celled spores of the fern Ceratopteris richardii Brogn. is influenced by gravity during a time period prior to the first cellular division designated a "polarity-determination window". After this window closes, control of polarity is seen in the downward (with respect to gravity) migration of the nucleus along the proximal face of the spore and the subsequent downward growth of the primary rhizoid. When spores are germinated on a clinostat the direction of nuclear migration and subsequent primary rhizoid growth is random. However, in each case the direction of nuclear migration predicts the direction of rhizoid elongation. Although it is the most obvious movement, the downward migration is not the first movement of the nucleus. During the polarity-determination window, the nucleus moves randomly within a region centered behind the trilete marking. While the polarity of many fern spores has been reported to be controlled by light, spores of C. richardii are the first documented to have their polarity influenced by gravity. Directional white light also affects the polarity of these spores, but this influence is slight and is secondary to that of gravity.

  10. Ceratopteris richardii (C-fern: A model for investigating adaptive modification of vascular plant cell walls

    Directory of Open Access Journals (Sweden)

    Olivier eLeroux

    2013-09-01

    Full Text Available Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterising cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they not yet available this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.

  11. Correlation Analysis of Two Hydrochemical Factors Affecting the Distribution of Ceratopteris thalictroides in China%影响水蕨分布的两个水化学因子相关性分析

    Institute of Scientific and Technical Information of China (English)

    董元火; 吴翠

    2009-01-01

    [Objective] This study was to analyze the two hydrochemical factors affecting the distribution of Ceratopteris thalictroides, further to provide basis for its habitat protection and population restoration. [Method] Twenty two hydrochemical parameters of 22 sampling sites in Chinas tropical and subtropical zones were respectively averaged for calculating their variation coefficients, of which the two showing significant differences were used for multiple comparisons and correlation analyses via least significant difference and correlation coefficient. [Result] The correlation coefficients of all the 22 tested hydrochemical parameters varied hugely, but only pH value and conductivity showed significantly differences in two water body (type A and type B). Analysis of correlation presented that pH value were positively correlated with conductivity; further the multiple comparisons showed that the significant difference of pH value was higher than that of conductivity. [Conclusion] With regard to the two hydrochemical parameters showing significant differences, pH value influences the distribution of C.thalictroides more.

  12. Alternation of generations and experimental design: a guided-inquiry lab exploring the nature of the her1 developmental mutant of Ceratopteris richardii (C-Fern).

    Science.gov (United States)

    Spiro, Mark D; Knisely, Karin I

    2008-01-01

    Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the unique aspects of the plant life cycle and to gain a practical knowledge of experimental design. An additional goal was to engage students regardless of their biology background. In our experience, plant biology, and the plant life cycle in particular, present a pedagogical challenge because of negative student attitudes and lack of experience with this topic. This lab uses the fern Ceratopteris richardii (C-Fern), a model system for teaching and research that is particularly useful for illustrating alternation of generations. This lab does not simply present the stages of the life cycle; it also uses knowledge of alternation of generations as a starting point for characterizing the her1 mutation that affects gametophyte sexual development. Students develop hypotheses, arrive at an appropriate experimental design, and carry out a guided inquiry on the mechanism underlying the her1 mutation. Quantitative assessment of student learning and attitudes demonstrate that this lab achieves the desired goals.

  13. Gravity and light control of the developmental polarity of regenerating protoplasts isolated from prothallial cells of the fern Ceratopteris richardii

    Science.gov (United States)

    Edwards, E. S.; Roux, S. J.

    1998-01-01

    A procedure has been developed for isolating protoplasts from prothalli of Ceratopteris richardii which can be cultured and are capable of regeneration. Protoplasts were isolated from 2-week-old gametophytes in a medium containing wall-digesting enzymes in 0.5 M sucrose, followed by purification of the released protoplasts by floating them up into a 0.5 M sorbitol layer. Regeneration occurred over a period of 10-24 days, and, under optimal osmotic conditions, followed the developmental pattern seen during spore germination, in that the first division gave rise to a primary rhizoid. Thus, prothallial protoplasts are comparable to germinating spores as suitable models for studies of developmental polarity in single cells. As in germinating spores, the polarity of development in regenerating protoplasts is influenced by the vectors of gravity and unilateral light. However, the relative influence of light in fixing this polarity is greater in regenerating protoplasts, while in germinating spores, the influence of gravity is greater.

  14. Ferns.

    Science.gov (United States)

    Russell, Helen Ross

    1991-01-01

    Contains several study methods using ferns. Includes exercises on fern propagation, gametophytes and fern hybrids, fern collection, microscope use, asexual reproduction, and fern photography. Background information describes identification techniques and the alternation of generations phenomenon. (MCO)

  15. Chemical constituents analysis and antidiabetic activity validation of four fern species from Taiwan.

    Science.gov (United States)

    Chen, Chen-Yu; Chiu, Fu-Yu; Lin, Yenshou; Huang, Wei-Jan; Hsieh, Po-Shiuan; Hsu, Feng-Lin

    2015-01-22

    Pterosins are abundant in ferns, and pterosin A was considered a novel activator of adenosine monophosphate-activated protein kinase, which is crucial for regulating blood glucose homeostasis. However, the distribution of pterosins in different species of ferns from various places in Taiwan is currently unclear. To address this question, the distribution of pterosins, glucose-uptake efficiency, and protective effects of pterosin A on β-cells were examined. Our results showed that three novel compounds, 13-chloro-spelosin 3-O-β-d-glucopyranoside (1), (3R)-Pterosin D 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (2), and (2R,3R)-Pterosin L 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (3), were isolated for the first time from four fern species (Ceratopteris thalictroides, Hypolepis punctata, Nephrolepis multiflora, and Pteridium revolutum) along with 27 known compounds. We also examined the distribution of these pterosin compounds in the mentioned fern species (except N. multiflora). Although all pterosin analogs exhibited the same effects in glucose uptake assays, pterosin A prevented cell death and reduced reactive oxygen species (ROS) production. This paper is the first report to provide new insights into the distribution of pterosins in ferns from Taiwan. The potential anti-diabetic activity of these novel phytocompounds warrants further functional studies.

  16. Detection of chlorophylls in spores of seven ferns.

    Science.gov (United States)

    Tseng, Mei-Hwei; Lin, Kuei-Huei; Huang, Yi-Jia; Chang, Ya-Lan; Huang, Sheng-Cih; Kuo, Li-Yaung; Huang, Yao-Moan

    2017-03-01

    Fern spores were traditionally classified into chlorophyllous (green) and nonchlorophyllous (nongreen) types based on the color visible to the naked eye. Recently, a third type, "cryptochlorophyllous spores", is recognized, and these spores are nongreen under white light but contain chlorophylls. Epifluorescence microscopy was previously used to detect chlorophylls in cryptochlorophyllous spores. In addition to epifluorescence microscopy, current study performed some other approaches, including spore-squash epifluorescence, absorption spectra, laser-induced fluorescence emission spectra, thin layer chromatography (TLC), and ultra-high performance liquid chromatography with ultraviolet and mass spectrometric detection (UHPLC-UV-MS) in order to detect chlorophylls of spores of seven ferns (Sphaeropteris lepifera, Ceratopteris thalictroides, Leptochilus wrightii, Leptochilus pothifolius, Lepidomicrosorum buergerianum, Osmunda banksiifolia, and Platycerium grande). Destructive methods, such as TLC and UHPLC-UV-MS, successfully detected chlorophylls inside the spores when their signals of red fluorescence under epifluorescence microscope were masked by spore wall. Although UHPLC-UV-MS analysis was the most sensitive and reliable for determining the chlorophylls of spores, spore-squash epifluorescence is not only reliable but also cost- and time-effective one among our study methods. In addition, we first confirmed that Lepidomicrosorium buergerianum, Leptochilus pothifolius, Leptochilus wrightii, and Platycerium grande, produce cryptochlorophyllous spores.

  17. Between Two Fern Genomes

    OpenAIRE

    Sessa, Emily B.; Banks, Jo; Michael S Barker; Der, Joshua P; Duffy, Aaron M; Graham, Sean W.; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D; Kathleen M. Pryer; Rothfels, Carl J.; Roux, Stanley J.; Salmi, Mari L; Sigel, Erin M.

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense divers...

  18. Structure and function of CrACA1, the major PM-type Ca2+-ATPase, expressed at the peak of the gravity-directed trans-cell calcium current in spores of the fern Ceratopteris richardii.

    Science.gov (United States)

    Bushart, T J; Cannon, A; Clark, G; Roux, S J

    2014-01-01

    Spores of the fern Ceratopteris richardii have proven to be a valuable single-cell system for studying gravity responses. The earliest cellular change directed by gravity in these cells is a trans-cell calcium current, which peaks near 10 h after the spores are induced to germinate. This current is needed for gravity-directed axis alignment, and its peak is coincident with the time period when gravity polarises the direction of subsequent nuclear migration and rhizoid growth. Transcriptomic analysis of genes expressed at the 10-h time point revealed several that encode proteins likely to be key components that either drive the current or regulate it. Notable among these is a plasma membrane (PM)-type Ca(2+) ATPase, CrACA1, whose activity pumping Ca(2+) out of cells is regulated by gravity. This report provides an initial characterisation of the structure and expression of this protein, and demonstrates its heterologous function complementing the K616 mutant of yeast, which is deficient in PM-type Ca(2+) pump activity. Gravity-induced changes in the trans-cell Ca(2+) current occur within seconds, a result consistent with the hypothesis that the force of gravity can rapidly alter the post-translational state of the channels and pumps that drive this current across spore cells. This report identifies a transporter likely to be a key driver of the current, CrACA1, and characterises the role of this protein in early germination and gravity-driven polarity fixation through analysis of expression levels, functional complementation and pharmacological treatments. These data, along with newly available transcriptomic data obtained at the 10-h time point, indicate that CrACA1 is present, functional and likely a major contributing component of the trans-cell Ca(2+) efflux. CrACA1 is not necessary for polar axis alignment, but pharmacological perturbations of it disrupt rhizoid development. These data support and help refine the post-translational modification model for

  19. Between two fern genomes.

    Science.gov (United States)

    Sessa, Emily B; Banks, Jo Ann; Barker, Michael S; Der, Joshua P; Duffy, Aaron M; Graham, Sean W; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D Blaine; Pryer, Kathleen M; Rothfels, Carl J; Roux, Stanley J; Salmi, Mari L; Sigel, Erin M; Soltis, Douglas E; Soltis, Pamela S; Stevenson, Dennis W; Wolf, Paul G

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves.

  20. Plant Development & the Fern Life Cycle: Using "Ceratopteris richardii."

    Science.gov (United States)

    Renzaglia, Karen S.; And Others

    1995-01-01

    Presents laboratory activities focusing on the development of sexually mature gametophytes from single-celled spores. Includes techniques for culture and manipulation of gametophyte development from spores that are applicable for hands-on activities for students at all levels. (MKR)

  1. An Exploration into Fern Genome Space.

    Science.gov (United States)

    Wolf, Paul G; Sessa, Emily B; Marchant, Daniel Blaine; Li, Fay-Wei; Rothfels, Carl J; Sigel, Erin M; Gitzendanner, Matthew A; Visger, Clayton J; Banks, Jo Ann; Soltis, Douglas E; Soltis, Pamela S; Pryer, Kathleen M; Der, Joshua P

    2015-08-26

    Ferns are one of the few remaining major clades of land plants for which a complete genome sequence is lacking. Knowledge of genome space in ferns will enable broad-scale comparative analyses of land plant genes and genomes, provide insights into genome evolution across green plants, and shed light on genetic and genomic features that characterize ferns, such as their high chromosome numbers and large genome sizes. As part of an initial exploration into fern genome space, we used a whole genome shotgun sequencing approach to obtain low-density coverage (∼0.4X to 2X) for six fern species from the Polypodiales (Ceratopteris, Pteridium, Polypodium, Cystopteris), Cyatheales (Plagiogyria), and Gleicheniales (Dipteris). We explore these data to characterize the proportion of the nuclear genome represented by repetitive sequences (including DNA transposons, retrotransposons, ribosomal DNA, and simple repeats) and protein-coding genes, and to extract chloroplast and mitochondrial genome sequences. Such initial sweeps of fern genomes can provide information useful for selecting a promising candidate fern species for whole genome sequencing. We also describe variation of genomic traits across our sample and highlight some differences and similarities in repeat structure between ferns and seed plants.

  2. Fern Habitats and Rare Ferns in Oklahoma

    Directory of Open Access Journals (Sweden)

    Bruce A. Smith

    2008-12-01

    Full Text Available This paper features some of the more common fern habitats in Oklahoma and provides information on four rare Oklahoma ferns from two fern families: Aspleniaceae and Pteridaceae. Surprisingly, ferns can be found in a variety of habitats across Oklahoma.

  3. Ferns: the missing link in shoot evolution and development

    Directory of Open Access Journals (Sweden)

    Andrew Robert George Plackett

    2015-11-01

    Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

  4. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    2003-01-01

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from 1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in micro-g compared to those developing on earth. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

  5. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of /micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from /1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in /micro-g compared to those developing on earth.

  6. The invention of WUS-like stem cell-promoting functions in plants predates leptosporangiate ferns.

    Science.gov (United States)

    Nardmann, Judith; Werr, Wolfgang

    2012-01-01

    The growth of land plants depends on stem cell-containing meristems which show major differences in their architecture from basal to higher plant species. In Arabidopsis, the stem cell niches in the shoot and root meristems are promoted by WUSCHEL (WUS) and WOX5, respectively. Both genes are members of a non-ancestral clade of the WUS-related homeobox (WOX) gene family, which is absent in extant bryophytes and lycophytes. Our analyses of five fern species suggest that a single WUS orthologue was present in the last common ancestor (LCA) of leptosporangiate ferns and seed plants. In the extant fern Ceratopteris richardii, the WUS pro-orthologue marks the pluripotent cell fate of immediate descendants of the root apical initial, so-called merophytes, which undergo a series of stereotypic cell divisions and give rise to all cell types of the root except the root cap. The invention of a WUS-like function within the WOX gene family in an ancestor of leptosporangiate ferns and seed plants and its amplification and sub-functionalisation to different stem cell niches might relate to the success of seed plants, especially angiosperms.

  7. Amy Lum Fern

    Science.gov (United States)

    Rossi, Joe

    2007-01-01

    This article presents an interview with Amy Lum Fern, Hawai'i Department of Education teacher from 1933 to 1972. Amy Lum Fern was born in Honolulu in 1909. She received her early education at Central Grammar School and later attended McKinley High School. After graduating from McKinley in 1928, she entered the University of Hawai'i, where she…

  8. Cryopreservation of fern spores

    Science.gov (United States)

    Spore banks for ferns are analogous to seed banks for angiosperms and provide a promising ex situ conservation tool because large quantities of germplasm with high genetic variation can be conserved in a small space with low economic and technical costs. Ferns produce two types of spores with very ...

  9. Conservation of fern spores

    Science.gov (United States)

    Ferns are a diverse and important group of plants, but diversity of species and populations are at risk from increasing social pressures, loss of habitat and climate change. Ex situ conservation is a useful strategy to limit decline in genetic diversity and requires technologies to preserve fern ger...

  10. Bracken fern poisoning

    Science.gov (United States)

    Bracken fern (Pteridium aquilinum) has worldwide distribution and in some areas dominated plant communities replacing desirable forages. Poisoning is identified as enzootic hematuria, bright blindness, and bracken staggers. This chapter reviews updates new information on the plant, the various poi...

  11. Flexible Envelope Request Notation (FERN)

    Science.gov (United States)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart

    1991-01-01

    The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

  12. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain li

  13. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  14. Ferns and fern allies of District Shopian, Kashmir Valley, India

    Directory of Open Access Journals (Sweden)

    SHAKOOR A. MIR

    2015-04-01

    Full Text Available Abstract. Mir SA, Mishra AK, Pala SA, Reshi ZA, Sharma MP. Ferns and fern allies of District Shopian, Kashmir Valley, India Biodiversitas 16: 27-43. Shopian, recently created hilly district of Kashmir valley, Jammu and Kashmir is surrounded by the lofty mountains of Pir-Panjal range. More than half area of district is occupied by different forests, subalpine, alpine and mountainous zones. Great altitudinal variation, adequate rainfall, high forest cover, large number of streams, springs and topographic variations render the district worthy for supporting rich fern flora. Therefore, the current study was aimed to undertake in-depth systematic survey of different habitats of Shopian for the collection of diversity of pteridophytes. Specimens were collected during 2010, 2011 and 2012 growing seasons from June to November. A total 81 species of ferns and fern allies belonging 27 genera and 11 families were reported. The dominant families of the region are Dryopteridaceae (25 species followed by Woodsiaceae (16 species, Aspleniaceae (13 species and Pteridaceae (12 species. Similarly, the dominant genera collected from here are Dryopteris (14 species, Asplenium (13, Polystichum (11 species and Athyrium (6 species. A list of the fern and fern allies, along with update nomenclature, their selected Synonym, diagnostic features, distributional and ecological notes have been provided here.

  15. New species of Malaysian ferns

    NARCIS (Netherlands)

    Holttum, R.E.

    1962-01-01

    The present paper includes descriptions of several new species of ferns found among recent collections from various parts of Malaysia; also two new combinations of names of species which are of interest on account of their taxonomic history.

  16. Floral homeotic genes were recruited from homologous MADS-box genes preexisting in the common ancestor of ferns and seed plants.

    Science.gov (United States)

    Münster, T; Pahnke, J; Di Rosa, A; Kim, J T; Martin, W; Saedler, H; Theissen, G

    1997-03-18

    Flowers sensu lato are short, specialized axes bearing closely aggregated sporophylls. They are typical for seed plants (spermatophytes) and are prominent in flowering plants sensu stricto (angiosperms), where they often comprise an attractive perianth. There is evidence that spermatophytes evolved from gymnosperm-like plants with a fern-like mode of reproduction called progymnosperms. It seems plausible, therefore, that the stamens/carpels and pollen sacs/nucelli of spermatophytes are homologous to fern sporophylls and sporangia, respectively. However, the exact mode and molecular basis of early seed and flower evolution is not yet known. Comparing flower developmental control genes to their homologs from lower plants that do not flower may help to clarify the issue. We have isolated and characterized MADS-box genes expressed in gametophytes and sporophytes of the fern Ceratopteris. The data indicate that at least two different MADS-box genes homologous to floral homeotic genes existed in the last common ancestor of contemporary vascular plants, some descendants of which underwent multiple duplications and diversifications and were recruited into novel developmental networks during the evolution of floral organs.

  17. SURVEY OF ORNAMENTAL FERNS, THEIR MORPHOLOGY AND ...

    African Journals Online (AJOL)

    ornamental ferns for environmental management and economic values. Ferns were collected from humid ... purposes, environmental protection, improvement and management in this region. ..... Journal of Current Research 2 (1):. 009-017.

  18. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1985-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  19. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1983-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  20. Conjunctival mucus ferning in hypovitaminosis A

    Directory of Open Access Journals (Sweden)

    Edward D

    1988-01-01

    Full Text Available The ocular ferning test was used to qualitatively assess mucus function in early stages of xerophthalmia. The results indicate that inspite of histological evidence of loss of goblet cells in the early stages, mucous function and production is sufficient to produce ferning. It is suggested that such derangements in mucous ferning may occur in more advanced stages of xerophthalmia.

  1. Ecological anatomy of ferns fronds

    Directory of Open Access Journals (Sweden)

    Nina M. Derzhavina

    2014-04-01

    Full Text Available Structural types of frond anatomy are distinguished on the basis of investigation of 30 species of homosporous ferns and with regard for literature: hydromorphic, hygromorphic, mesomorphic, subxeromorphic, and subsucculent (cryptic succulent. Following frond traits are of highest adaptive value: their area and thickness, type of mesophyll, dry weight of an area unit – specific superficial density, cellular volume, and number of cells per unit of frond area.

  2. Note on apomixis in ferns

    Directory of Open Access Journals (Sweden)

    J. P. Tilquin

    2014-02-01

    Full Text Available In 1964, two new types of apogamy were described in ferns. The sporangia contain at the starting-point 16 spore mother cells and at the endingpoint 32 diplospores. On the one hand, the meiosis is replaced by a mitosis, on the other hand, the first meiotic division aborts and the restituition nucleus divides mitotically. The author's observations imply that the second process is a variant of the first one.

  3. Further Experiments with Ferns in Culture: Regeneration.

    Science.gov (United States)

    Sheffield, Elizabeth; Attree, Stephen M.

    1983-01-01

    Ferns in culture provide versatile and easily manipulated material for a wide variety of experiments and observations. Information is provided that supplements earlier reports of the vast experimental potential of these cryptogams and outlines laboratory exercises which reveal the regenerative behavior of fern tissue. (JN)

  4. Alternation of Generations and Experimental Design: A Guided-Inquiry Lab Exploring the Nature of the "her1" Developmental Mutant of "Ceratopteris richardii" (C-Fern)

    Science.gov (United States)

    Spiro, Mark D.; Knisely, Karin I.

    2008-01-01

    Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the…

  5. Alternation of Generations and Experimental Design: A Guided-Inquiry Lab Exploring the Nature of the her1 Developmental Mutant of Ceratopteris richardii (C-Fern)

    OpenAIRE

    2008-01-01

    Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the unique aspects of the plant life cycle and to gain a practical knowledge of experimental design. An additional goal was to engage students regardless of...

  6. FERN Ethnomedicinal Plant Database: Exploring Fern Ethnomedicinal Plants Knowledge for Computational Drug Discovery.

    Science.gov (United States)

    Thakar, Sambhaji B; Ghorpade, Pradnya N; Kale, Manisha V; Sonawane, Kailas D

    2015-01-01

    Fern plants are known for their ethnomedicinal applications. Huge amount of fern medicinal plants information is scattered in the form of text. Hence, database development would be an appropriate endeavor to cope with the situation. So by looking at the importance of medicinally useful fern plants, we developed a web based database which contains information about several group of ferns, their medicinal uses, chemical constituents as well as protein/enzyme sequences isolated from different fern plants. Fern ethnomedicinal plant database is an all-embracing, content management web-based database system, used to retrieve collection of factual knowledge related to the ethnomedicinal fern species. Most of the protein/enzyme sequences have been extracted from NCBI Protein sequence database. The fern species, family name, identification, taxonomy ID from NCBI, geographical occurrence, trial for, plant parts used, ethnomedicinal importance, morphological characteristics, collected from various scientific literatures and journals available in the text form. NCBI's BLAST, InterPro, phylogeny, Clustal W web source has also been provided for the future comparative studies. So users can get information related to fern plants and their medicinal applications at one place. This Fern ethnomedicinal plant database includes information of 100 fern medicinal species. This web based database would be an advantageous to derive information specifically for computational drug discovery, botanists or botanical interested persons, pharmacologists, researchers, biochemists, plant biotechnologists, ayurvedic practitioners, doctors/pharmacists, traditional medicinal users, farmers, agricultural students and teachers from universities as well as colleges and finally fern plant lovers. This effort would be useful to provide essential knowledge for the users about the adventitious applications for drug discovery, applications, conservation of fern species around the world and finally to create

  7. Genome evolution of ferns: evidence for relative stasis of genome size across the fern phylogeny.

    Science.gov (United States)

    Clark, James; Hidalgo, Oriane; Pellicer, Jaume; Liu, Hongmei; Marquardt, Jeannine; Robert, Yannis; Christenhusz, Maarten; Zhang, Shouzhou; Gibby, Mary; Leitch, Ilia J; Schneider, Harald

    2016-05-01

    The genome evolution of ferns has been considered to be relatively static compared with angiosperms. In this study, we analyse genome size data and chromosome numbers in a phylogenetic framework to explore three hypotheses: the correlation of genome size and chromosome number, the origin of modern ferns from ancestors with high chromosome numbers, and the occurrence of several whole-genome duplications during the evolution of ferns. To achieve this, we generated new genome size data, increasing the percentage of fern species with genome sizes estimated to 2.8% of extant diversity, and ensuring a comprehensive phylogenetic coverage including at least three species from each fern order. Genome size was correlated with chromosome number across all ferns despite some substantial variation in both traits. We observed a trend towards conservation of the amount of DNA per chromosome, although Osmundaceae and Psilotaceae have substantially larger chromosomes. Reconstruction of the ancestral genome traits suggested that the earliest ferns were already characterized by possessing high chromosome numbers and that the earliest divergences in ferns were correlated with substantial karyological changes. Evidence for repeated whole-genome duplications was found across the phylogeny. Fern genomes tend to evolve slowly, albeit genome rearrangements occur in some clades. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  8. Fern and bryophyte endozoochory by slugs.

    Science.gov (United States)

    Boch, Steffen; Berlinger, Matthias; Fischer, Markus; Knop, Eva; Nentwig, Wolfgang; Türke, Manfred; Prati, Daniel

    2013-07-01

    Endozoochory plays a prominent role for the dispersal of seed plants, and dispersal vectors are well known. However, for taxa such as ferns and bryophytes, endozoochory has only been suggested anecdotally but never tested in controlled experiments. We fed fertile leaflets of three ferns and capsules of four bryophyte species to three slug species. We found that, overall, spores germinated from slug feces in 57.3% of all 89 fern and in 51.3% of all 117 bryophyte samples, showing that the spores survived gut passage of slugs. Moreover, the number of samples within which spores successfully germinated did not differ among plant species but varied strongly among slug species. This opens new ecological perspectives suggesting that fern and bryophyte endozoochory by gastropods is a so-far-overlooked mode of dispersal, which might increase local population sizes of these taxa by spore deposition on suitable substrates.

  9. Additions to the fern flora of Sulawesi

    NARCIS (Netherlands)

    Hovenkamp, P.H.; Joncheere, de G.J.

    1988-01-01

    A number of additions to the fern flora of Celebes are given here, including also the description of 15 new taxa in the Polypodiaceae, Cyatheaceae, Dennstaedtiaceae, Thelypteridaceae, Aspleniaceae, and Davalliaceae.

  10. Trends and concepts in fern classification

    Science.gov (United States)

    Christenhusz, Maarten J. M.; Chase, Mark W.

    2014-01-01

    Background and Aims Throughout the history of fern classification, familial and generic concepts have been highly labile. Many classifications and evolutionary schemes have been proposed during the last two centuries, reflecting different interpretations of the available evidence. Knowledge of fern structure and life histories has increased through time, providing more evidence on which to base ideas of possible relationships, and classification has changed accordingly. This paper reviews previous classifications of ferns and presents ideas on how to achieve a more stable consensus. Scope An historical overview is provided from the first to the most recent fern classifications, from which conclusions are drawn on past changes and future trends. The problematic concept of family in ferns is discussed, with a particular focus on how this has changed over time. The history of molecular studies and the most recent findings are also presented. Key Results Fern classification generally shows a trend from highly artificial, based on an interpretation of a few extrinsic characters, via natural classifications derived from a multitude of intrinsic characters, towards more evolutionary circumscriptions of groups that do not in general align well with the distribution of these previously used characters. It also shows a progression from a few broad family concepts to systems that recognized many more narrowly and highly controversially circumscribed families; currently, the number of families recognized is stabilizing somewhere between these extremes. Placement of many genera was uncertain until the arrival of molecular phylogenetics, which has rapidly been improving our understanding of fern relationships. As a collective category, the so-called ‘fern allies’ (e.g. Lycopodiales, Psilotaceae, Equisetaceae) were unsurprisingly found to be polyphyletic, and the term should be abandoned. Lycopodiaceae, Selaginellaceae and Isoëtaceae form a clade (the lycopods) that is

  11. Epiphytism in ferns: diversity and history.

    Science.gov (United States)

    Dubuisson, Jean-Yves; Schneider, Harald; Hennequin, Sabine

    2009-01-01

    As for other vascular plants, numerous adaptive strategies have been selected in epiphytic ferns in order to survive in a constraining and desiccating environment and thus to prevent dehydration and/or to access to water and nutrients. Here we present some of the specializations that allow ferns to survive in this particular habitat. Some of the most spectacular epiphytic specializations are observed in the Polypodiaceae family, involving humus-collectors which entrap humus in specialized organs, and ant-plant mutualism strategies. We then address the question of epiphytism in an evolutionary context. There is little fossil evidence of vascular epiphytes. Inferring the evolution of epiphytism in extant ferns shows that diversification of major living epiphytic groups mostly occurred in the Tertiary. Finally, we focus on the Hymenophyllaceae family which provides an original example of hygrophilous epiphytic strategy that is unique in vascular plants.

  12. Fern rhizomes as fodder in Norway

    OpenAIRE

    Alm, Torbjørn

    2016-01-01

    Background Although ferns are often known under collective names in Norway, e.g. blom, a substantial number of vernacular names for individual fern species are known, in particular for useful or poisonous taxa. In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition’s core area is found in the two North Norwegian counties of Nordland and Troms, in accordance with the ...

  13. Random grid fern for visual tracking

    Science.gov (United States)

    Cheng, Fei; Liu, Kai; Zhang, Jin; Li, YunSong

    2014-05-01

    Visual tracking is one of the significant research directions in computer vision. Although standard random ferns tracking method obtains a good performance for the random spatial arrangement of binary tests, the effect of the locality of image on ferns description ability are ignored and prevent them to describe the object more accurately and robustly. This paper proposes a novel spatial arrangement of binary tests to divide the bounding box into grids in order to keep more details of the image for visual tracking. Experimental results show that this method can improve tracking accuracy effectively.

  14. [Lectins of Dryopteris Adans fern species].

    Science.gov (United States)

    Basheka, O V; Stetsenko, N M; Pogorila, N F

    1999-01-01

    Lectin activity of three ferns species (Dryopteris bushiana Fom., D. laeta (Kom.) C. Chr, D. pseudomas (Wollaston) Holub et Pouzar) has been studied. We used hemagglutination reaction albumin and globulin fractions of fronds and rhizomes extracts with rat erythrocytes. The frond extract of D. pseudomas have shown higher activity as compared with other extracts. The lectin activity of D. laeta leaves was absent. The rhizomes of all three fern species could be characterized as high activity. Based on lectin activity the species were placed as follows order: D. buschiana > D. pseudomas > D. laeta. The dependence with lectin activity and elements (Mn, Fe, Cu, Ni, Zn, Pb, Rb, Sr) content were not found.

  15. Two new fern chloroplasts and decelerated evolution linked to the long generation time in tree ferns.

    Science.gov (United States)

    Zhong, Bojian; Fong, Richard; Collins, Lesley J; McLenachan, Patricia A; Penny, David

    2014-04-30

    We report the chloroplast genomes of a tree fern (Dicksonia squarrosa) and a "fern ally" (Tmesipteris elongata), and show that the phylogeny of early land plants is basically as expected, and the estimates of divergence time are largely unaffected after removing the fastest evolving sites. The tree fern shows the major reduction in the rate of evolution, and there has been a major slowdown in the rate of mutation in both families of tree ferns. We suggest that this is related to a generation time effect; if there is a long time period between generations, then this is probably incompatible with a high mutation rate because otherwise nearly every propagule would probably have several lethal mutations. This effect will be especially strong in organisms that have large numbers of cell divisions between generations. This shows the necessity of going beyond phylogeny and integrating its study with other properties of organisms.

  16. Food uses of ferns in China: a review

    Directory of Open Access Journals (Sweden)

    Yujing Liu

    2012-11-01

    Full Text Available Edible ferns are some of the most important wild vegetables in China. This paper reviews their food uses. The history of eating ferns in China may go back as far as 3000 years. An ethnobotanical inventory of edible ferns was created, with 52 species (including 4 varieties, which were traditionally used. The potential species number of edible ferns was estimated as 144 species (including 4 varieties. The cuisines, products and chemical components of ferns were also summarized. The most commonly eaten fern, Pteridium aquilinum var. latiusculum, was discussed in terms of its toxicity, massive productivity and development strategies. Suggestions and recommendations were proposed for the future development of edible ferns in China.

  17. The evolution of chloroplast genes and genomes in ferns.

    Science.gov (United States)

    Wolf, Paul G; Der, Joshua P; Duffy, Aaron M; Davidson, Jacob B; Grusz, Amanda L; Pryer, Kathleen M

    2011-07-01

    Most of the publicly available data on chloroplast (plastid) genes and genomes come from seed plants, with relatively little information from their sister group, the ferns. Here we describe several broad evolutionary patterns and processes in fern plastid genomes (plastomes), and we include some new plastome sequence data. We review what we know about the evolutionary history of plastome structure across the fern phylogeny and we compare plastome organization and patterns of evolution in ferns to those in seed plants. A large clade of ferns is characterized by a plastome that has been reorganized with respect to the ancestral gene order (a similar order that is ancestral in seed plants). We review the sequence of inversions that gave rise to this organization. We also explore global nucleotide substitution patterns in ferns versus those found in seed plants across plastid genes, and we review the high levels of RNA editing observed in fern plastomes.

  18. A new genus of Lindsaeoid ferns

    NARCIS (Netherlands)

    Kramer, K.U.

    1957-01-01

    In revising the New World representatives of the genus Lindsaea, the author came across a fern specimen from Borneo preserved in the Rijksherbarium, Leiden, that did not seem to fit into any described genus. It had been described as Schizoloma stortii v. A. v. R., but in the author’s opinion the gen

  19. Photosynthesis limitations in three fern species.

    Science.gov (United States)

    Gago, Jorge; Coopman, Rafael E; Cabrera, Hernán Marino; Hermida, Carmen; Molins, Arántzazu; Conesa, Miquel À; Galmés, Jeroni; Ribas-Carbó, Miquel; Flexas, Jaume

    2013-12-01

    Maximum photosynthesis rates in ferns are generally lower than those of seed plants, but little is known about the limiting factors, which are crucial to understand the evolution of photosynthesis in land plants. To address this issue, a gas exchange/chlorophyll fluorescence analysis was performed in three fern species spanning high phylogenetic range within Polypodiopsida (Osmunda regalis, Blechnum gibbum and Nephrolepis exaltata) to determine their maximum net photosynthesis (AN ), stomatal (gs ) and mesophyll (gm ) conductances to CO2 , and the maximum velocity of carboxylation (Vc,max ). The in vitro Rubisco specificity factor (SC /O ) was also determined. All three species had values for SC /O similar to those typical of seed plants, but values of AN , gs , gm and Vc,max were within the lowest range of those observed in seed plants. In addition, gs was unresponsive to light and CO2 , as already described in other fern species. On the contrary, gm varied with changes CO2 . A quantitative photosynthesis limitation analysis suggested that early land plants (ferns) presented not only stomatal limitations-which were less adjustable to the environment-but also restricted gm and Vc,max , resulting in limited maximum photosynthesis rates.

  20. How Fern Creek Is Beating Goliath

    Science.gov (United States)

    Donovan, Margaret; Galatowitsch, Patrick; Hefferin, Keri; Highland, Shanita

    2013-01-01

    The "David" is Fern Creek Elementary, a small urban school in Orlando, Florida, that serves an overwhelmingly disadvantaged student population. The "Goliaths" are the mountains of problems that many inner-city students face--poverty, homelessness, mobility, instability, limited parent involvement, and violent neighborhood…

  1. The photosynthetic capacity in 35 ferns and fern allies: mesophyll CO2 diffusion as a key trait.

    Science.gov (United States)

    Tosens, Tiina; Nishida, Keisuke; Gago, Jorge; Coopman, Rafael Eduardo; Cabrera, Hernán Marino; Carriquí, Marc; Laanisto, Lauri; Morales, Loreto; Nadal, Miquel; Rojas, Roke; Talts, Eero; Tomas, Magdalena; Hanba, Yuko; Niinemets, Ülo; Flexas, Jaume

    2016-03-01

    Ferns and fern allies have low photosynthetic rates compared with seed plants. Their photosynthesis is thought to be limited principally by physical CO2 diffusion from the atmosphere to chloroplasts. The aim of this study was to understand the reasons for low photosynthesis in species of ferns and fern allies (Lycopodiopsida and Polypodiopsida). We performed a comprehensive assessment of the foliar gas-exchange and mesophyll structural traits involved in photosynthetic function for 35 species of ferns and fern allies. Additionally, the leaf economics spectrum (the interrelationships between photosynthetic capacity and leaf/frond traits such as leaf dry mass per unit area or nitrogen content) was tested. Low mesophyll conductance to CO2 was the main cause for low photosynthesis in ferns and fern allies, which, in turn, was associated with thick cell walls and reduced chloroplast distribution towards intercellular mesophyll air spaces. Generally, the leaf economics spectrum in ferns follows a trend similar to that in seed plants. Nevertheless, ferns and allies had less nitrogen per unit DW than seed plants (i.e. the same slope but a different intercept) and lower photosynthesis rates per leaf mass area and per unit of nitrogen.

  2. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    Science.gov (United States)

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  3. The fern sporangium: a unique catapult.

    OpenAIRE

    Noblin, X.; Rojas, N. O.; Westbrook, J; Llorens, C.; Argentina, M.; Dumais, J.

    2012-01-01

    International audience; Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of ...

  4. Thirteen new records of ferns from Brazil.

    Science.gov (United States)

    Almeida, Thais Elias; Salino, Alexandre

    2015-01-01

    Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyatheasubincisa, Cyclodiumtrianae, Elaphoglossumstenophyllum, Hypoderrisbrauniana, Pleopeltisstolzei, Thelypterisarcana, Thelypteriscomosa, Thelypterisvaldepilosa), two are from Pará state (Polypodiumflagellare, Tectariaheracleifolia), one from Minas Gerais state (Alsophilasalvinii), one from Ceará state (Campyloneurumcostatum) and one from Bahia state (Thelypterisrolandii). Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  5. Towards Resolving the Complete Fern Tree of Life

    OpenAIRE

    Samuli Lehtonen

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likel...

  6. The fern sporangium: an ultrafast natural catapult

    Science.gov (United States)

    Noblin, Xavier; Argentina, Mederic; Westbrook, Jared; Llorens, Coraline; Rojas, Nicolas; Dumais, Jacques

    2012-02-01

    Plants have developed fascinating mechanisms to create ultra fast movements that often reach the upper limit allowed by physical laws. Inspiration for new technologies is one of the reasons for the strong interest for these mechanisms, along with the deep interest of understanding complex, natural systems. The fern sporangium is a capsule that contains the spores, it is surrounded by a row of cells called the annulus which acts as a beam. Due to the water evaporation from its cells, the annulus bends strongly and induces elastic energy storage during an opening phase. The tension in the cells breaks when cavitation bubbles appear in the cells, leading to a fast release of the elastic energy. The fern sporangium then acts as a catapult which ejects rapidly its spores by closing back to the initial closed shape. We have analyzed the slow opening motion and the fast catapulting mechanism. We found that the catapult motion involves two time scales, showing a very original behavior. In man-made catapults, the recoil motion needs to be arrested by a cross bar so that the projectile is released from the arm. We show here that the fern sporangium replaces the essential cross bar by an elegant poroelastic damping, leading to a completely autonomous, efficient device.

  7. Biochemical and evolutionary aspects of arthropod predation on ferns.

    Science.gov (United States)

    Balick, Michael J; Furth, David G; Cooper-Driver, Gillian

    1978-01-01

    The widely held assumption that very few arthropods feed on ferns was questioned following field observations of arthropod damage on ferns in the state of Veracruz, Mexico. The extent and type of damage was recorded and it was found that in a measured locality, ferns were no less attacked than the angiospermous flora. As chemistry and arthropod host relationships have been shown to be so closely intertwined, plants collected in the field were analysed for both condensed tannins and cyanogenic glycosides, compounds known to be effective deterrents in temperate climates. Although all ferns tested contained tannins these did not appear to inhibit predation. Cyanogenic glycosides were present in only 3% of the fern species analysed, and it is, therefore, unlikely that they play a significant role as defensive compounds in the ferns examined.A literature search revealed a large number of ferns cited as being arthropod hosts. Approximately 420 named species of arthropods have been recorded, the majority of which are from the orders Coleoptera, Hymenoptera, Lepidoptera, and Hemiptera. Both evolutionary primitive (sawflies) and advanced (moths) arthropods are reported to be present on ferns suggesting possible coevolution of arthropods and ferns both before and after the radiation of angiosperms.

  8. Distribution and dynamics of hayscented fern following stand harvest

    Science.gov (United States)

    Songlin Fei; Peter J. Gould; Melanie J. Kaeser; Kim C. Steiner

    2008-01-01

    The distribution and dynamics of hayscented fern were examined as part of a large-scale study of oak regeneration in Pennsylvania. The study included 69 stands covering 3,333 acres in two physiographic provinces. Hayscented fern was more widely distributed and occurred at higher densities in the Allegheny Plateau physiographic provinces versus the Ridge and Valley...

  9. Klukiopsis jurassica--A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  10. Towards resolving the complete fern tree of life.

    Science.gov (United States)

    Lehtonen, Samuli

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  11. Thirteen new records of ferns from Brazil

    Directory of Open Access Journals (Sweden)

    Thais Almeida

    2015-02-01

    Full Text Available Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyathea subincisa, Cyclodium trianae, Elaphoglossum stenophyllum, Hypoderris brauniana, Pleopeltis stolzei, Thelypteris arcana, Thelypteris comosa, Thelypteris valdepilosa, two are from Pará state (Polypodium flagellare, Tectaria heracleifolia, one from Minas Gerais state (Alsophila salvinii, one from Ceará state (Campyloneurum costatum and one from Bahia state (Thelypteris rolandii. Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  12. Chloroplast genome evolution in early diverged leptosporangiate ferns.

    Science.gov (United States)

    Kim, Hyoung Tae; Chung, Myong Gi; Kim, Ki-Joong

    2014-05-01

    In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that frequently occurred in the cp genome of leptosporangiate ferns were not found in the cp genome of O. cinnamomea. In addition, putative RNA editing sites in the cp genome were rare in O. cinnamomea, even though the sites were frequently predicted to be present in leptosporangiate ferns. The complete cp genome sequence of Diplopterygium glaucum (Gleicheniales) was 151,007 bp and has a 9.7 kb inversion between the trnL-CAA and trnVGCA genes when compared to O. cinnamomea. Several repeated sequences were detected around the inversion break points. The complete cp genome sequence of Lygodium japonicum (Schizaeales) was 157,142 bp and a deletion of the rpoC1 intron was detected. This intron loss was shared by all of the studied species of the genus Lygodium. The GC contents and the effective numbers of codons (ENCs) in ferns varied significantly when compared to seed plants. The ENC values of the early diverged leptosporangiate ferns showed intermediate levels between eusporangiate and core leptosporangiate ferns. However, our phylogenetic tree based on all of the cp gene sequences clearly indicated that the cp genome similarity between O. cinnamomea (Osmundales) and eusporangiate ferns are symplesiomorphies, rather than synapomorphies. Therefore, our data is in agreement with the view that Osmundales is a distinct early diverged lineage in the leptosporangiate ferns.

  13. A Catskill Flora and Economic Botany, I: Pteridophyta. The Ferns and Fern Allies. Bulletin No. 438, New York State Museum.

    Science.gov (United States)

    Brooks, Karl L.

    The information contained within this guide about flora of the ferns and fern allies of the Catskill Mountains of New York State covers medical and food uses of the plants, as well as the more typical floristic data of keys, drawings, and plant descriptions. (CS)

  14. Effects of temperature and desiccation on ex situ conservation of nongreen fern spores

    Science.gov (United States)

    Conservation of the genetic diversity of ferns is limited by the paucity of ex situ spore banks. Conflicting reports of fern spore response to low temperature and moisture impedes establishment of fern spore banks. There is little information available to evaluate longevity of fern spores under dif...

  15. Evolutionary Conservation of ABA Signaling for Stomatal Closure in Ferns.

    Science.gov (United States)

    Cai, Shengguan; Chen, Guang; Wang, Yuanyuan; Huang, Yuqing; Marchant, Blaine; Wang, Yizhou; Yang, Qian; Dai, Fei; Hills, Adrian; Franks, Peter J; Nevo, Eviatar; Soltis, Doug; Soltis, Pamela; Sessa, Emily; Wolf, Paul G; Xue, Dawei; Zhang, Guoping; Pogson, Barry J; Blatt, Mike R; Chen, Zhong-Hua

    2017-02-23

    ABA-driven stomatal regulation reportedly evolved after the divergence of ferns, during the early evolution of seed plants approximately 360 Mya. This hypothesis is based on the observation that the stomata of certain fern species are unresponsive to ABA, but exhibit passive hydraulic control. However, ABA-induced stomatal closure was detected in some mosses and lycophytes. Here, we observed that a number of ABA signaling and membrane transporter protein families diversified over the evolutionary history of land plants. The aquatic ferns Azolla filiculoides and Salvinia cucullata have representatives of 23 families of proteins orthologous to those of Arabidopsis thaliana and all other land plant species studied. Phylogenetic analysis of the key ABA signaling proteins indicates an evolutionarily conserved stomatal response to ABA. Moreover, comparative transcriptomic analysis has identified a suite of ABA responsive genes that differentially expressed in a terrestrial fern species, Polystichum proliferum. These genes encode proteins associated with ABA biosynthesis, transport, reception, transcription, signaling, and ion and sugar transport, which fit the general ABA signaling pathway constructed from Arabidopsis thaliana and Hordeum vulgare. The retention of these key ABA-responsive genes could have had a profound effect on the adaptation of ferns to dry conditions. Furthermore, stomatal assays have shown the primary evidence for ABA-induced closure of stomata in two terrestrial fern species P. proliferum and Nephrolepis exaltata. In summary, we report new molecular and physiological evidence for the presence of active stomatal control in ferns.

  16. First insights into fern matK phylogeny.

    Science.gov (United States)

    Kuo, Li-Yaung; Li, Fay-Wei; Chiou, Wen-Liang; Wang, Chun-Neng

    2011-06-01

    MatK, the only maturase gene in the land plant plastid genome, is a very popular phylogenetic marker that has been extensively applied in reconstructing angiosperm phylogeny. However, the use of matK in fern phylogeny is largely unknown, due to difficulties with amplification: ferns have lost the flanking trnK exons, typically the region used for designing stable priming sites. We developed primers that are either universal or lineage-specific that successfully amplify matK across all fern families. To evaluate whether matK is as powerful a phylogenetic marker in ferns as in angiosperms, we compared its sequence characteristics and phylogenetic performance to those of rbcL and atpA. Among these three genes, matK has the highest variability and substitution evenness, yet shows the least homoplasy. Most importantly, applying matK in fern phylogenetics better resolved relationships among families, especially within eupolypods I and II. Here we demonstrate the power of matK for fern phylogenetic reconstruction, as well as provide primers and extensive sequence data that will greatly facilitate future evolutionary studies of ferns.

  17. The evolution, morphology and development of fern leaves

    Directory of Open Access Journals (Sweden)

    Alejandra eVasco

    2013-09-01

    Full Text Available Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearl all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.

  18. The fern sporangium: a unique catapult.

    Science.gov (United States)

    Noblin, X; Rojas, N O; Westbrook, J; Llorens, C; Argentina, M; Dumais, J

    2012-03-16

    Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.

  19. Some new external flavonoids from American ferns

    Energy Technology Data Exchange (ETDEWEB)

    Wollenweber, E.

    1979-01-01

    American gymnogrammoid ferns have been analysed for the flavonoid aglycones present in frond exudates. They are predominantly methylated chalcones, dihydrochalcones, flavones, and flavonols, occurring mostly as farinose deposit (''ceraceous indument''). This is the first report of external flavonoids on Pterozonium species; a chalcone has been identified. On Cheilanthes kaulfussii and Cheilanthes viscida traces of flavonoid aglycones are observed, dissolved in lipophilic exudate material. On Pellaea longimucronata a flavonol is found even on leaves which appear glaucous. 2',4',6'-Trihydroxychalcone is found for the second time in the plant kingdom on Adiantum sulphureum. Galangin-3,7-dimethylether is found as a new natural flavonol on Cheilanthes kaulfussii. In addition, samples of Pityrogramma chrysoconia and Pit. triangularis var. maxonii have been investigated. The results indicate chemotaxonomic implication of flavonoid patterns.

  20. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    Directory of Open Access Journals (Sweden)

    Ionica Deliu

    2013-12-01

    Full Text Available The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derived remedies. In this study the antimicrobial effect of methanolic and ethanolic extracts from three fern species were tested. The extracts were gained from gametophytic stage of ferns obtained in vitro. The most obvious effect was observed for Asplenium trichomanes-ramosum extract. The total polyphenols and flavonoids content were established, too.

  1. Status Report, Phyllitis scolopendrium (L.) Newm. Var. Americana Fern

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Status report concerning theAmerican Hart's Tongue Fern in the US and Canada is reviwed concerning all known populations - including those presumed to be extirpated....

  2. Fern Biology in Mexico - (A Class Field Program)

    Science.gov (United States)

    Tryon, Rolla; And Others

    1973-01-01

    Organized field trips in the tropics proved to be an effective way to gather new information about ferns. The areas of study covered were: systematics and ecology, cytology and gametophyte structure, and morphogenesis and physiology. (PS)

  3. Using Water Clover to Demonstrate Sexual Reproduction in Ferns.

    Science.gov (United States)

    Settle, Wilbur J.

    1980-01-01

    Procedures are described for preparing spores from the fern, water clover, for an educational demonstration of germination and sexual reproduction. The demonstration is recommended for biology instructors who want to illustrate the alternation of phases in plants. (SA)

  4. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    OpenAIRE

    Ionica Deliu; Carmen Bejan; Emilia Vişoiu; Liliana Cristina Soare

    2013-01-01

    The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derive...

  5. Gene transfer from a parasitic flowering plant to a fern

    OpenAIRE

    Davis, Charles C.; Anderson, William R.; Wurdack, Kenneth J

    2005-01-01

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps fro...

  6. The evolution of chloroplast genome structure in ferns.

    Science.gov (United States)

    Wolf, Paul G; Roper, Jessie M; Duffy, Aaron M

    2010-09-01

    The plastid genome (plastome) is a rich source of phylogenetic and other comparative data in plants. Most land plants possess a plastome of similar structure. However, in a major group of plants, the ferns, a unique plastome structure has evolved. The gene order in ferns has been explained by a series of genomic inversions relative to the plastome organization of seed plants. Here, we examine for the first time the structure of the plastome across fern phylogeny. We used a PCR-based strategy to map and partially sequence plastomes. We found that a pair of partially overlapping inversions in the region of the inverted repeat occurred in the common ancestor of most ferns. However, the ancestral (seed plant) structure is still found in early diverging branches leading to the osmundoid and filmy fern lineages. We found that a second pair of overlapping inversions occurred on a branch leading to the core leptosporangiates. We also found that the unique placement of the gene matK in ferns (lacking a flanking intron) is not a result of a large-scale inversion, as previously thought. This is because the intron loss maps to an earlier point on the phylogeny than the nearby inversion. We speculate on why inversions may occur in pairs and what this may mean for the dynamics of plastome evolution.

  7. Reconstructed tree fern Alethopteris zeilleri (Carboniferous, Medullosales)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Department of Earth Sciences, University College of Cape Breton, Sydney, Nova, Scotia (Canada B1P 6L2)

    2007-01-02

    From a smaller open-pit area in the roof shale of the basal Cantabrian coal seam in Sydney Coalfield, Cape Breton Island, Nova Scotia, Canada, large amounts of the pteridosperm foliage Alethopteris zeilleri (Ragot) were found. This foliage is associated with abundant, naked medullosalean axes and dichotomies of varying sizes, up to 0.80-m long, cauline structures 0.90 m and 1.3 m long, detached ovules assigned to Pachytesta incrassata Brongniart, rare male-pollen organs of the type Dolerotheca Halle, rooted tree ferns in life position, and one specimen each of a juvenile medullosalean frond and root mantle. The fossils are compression/impression-preserved, and the foliage yielded thickly cutinized cuticles with unoriented cells (57-103 by 27-57 {mu}m) in intercostal fields. Ultimate rachises, and abaxial surfaces (excluding costal fields) show a mixture of simple and complexly-branched trichomes, and two different structural bases. These, together with fractal dimensionality of curvatures of anticlinal walls in intercostal fields, have taxonomic potential for alethopterids. The finds suggest reconstructing A. zeilleri (Ragot) as a tree, 5-7 m high, that bore both P. incrassata Brongniart and Dolerotheca-type fructifications. Its habitat was low-land coastal plains in the Pennsylvanian coal swamps of ancestral Sydney Coalfield. (author)

  8. Involvement of allelopathy in the formation of monospecific colonies of ferns.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2015-05-01

    Some fern species often dominate plant communities by forming large monospecific colonies. However, the potential mechanism for this domination of the ferns remains obscure. Many plants secrete a wide range of compounds into the rhizosphere and change the chemical and physical properties of the rhizosphere soil. Through the secretion of compounds, such as allelopathic substances, plants inhibit the germination and growth of neighboring plants to compete more effectively for the resources. Ferns contain a variety of secondary metabolites and some of those compounds are released from the ferns into the rhizosphere soil, either as exudates from living ferns or by decomposition of fern residues in sufficient quantities to affect the germination and growth of neighboring plants as allelopathic substances. Therefore, allelopathic chemical interaction of the ferns with neighboring plants may play an important role in the formation of the monospecific colonies of the ferns.

  9. Towards resolving the complete fern tree of life.

    Directory of Open Access Journals (Sweden)

    Samuli Lehtonen

    Full Text Available In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  10. Nicotinamide metabolism in ferns: formation of nicotinic acid glucoside.

    Science.gov (United States)

    Ashihara, Hiroshi; Yin, Yuling; Watanabe, Shin

    2011-03-01

    The metabolic fate of [carbonyl-(14)C]nicotinamide was investigated in 9 fern species, Psilotum nudum, Angiopteris evecta, Lygodium japonicum, Acrostichum aureum, Asplenium antiquum, Diplazium subsinuatum, Thelypteris acuminate, Blechnum orientale and Crytomium fortune. All fern species produce a large quantity of nicotinic acid glucoside from [(14)C]nicotinamide, but trigonelline formation is very low. Increases in the release of (14)CO(2) with incubation time was accompanied by decreases in [carboxyl-(14)C]nicotinic acid glucoside. There was slight stimulation of nicotinic acid glucoside formation by 250 mM NaCl in mature leaves of the mangrove fern, Acrostichum aureum, but it is unlikely that this compound acts as a compatible solute. Nicotinamide and nicotinic acid salvage for pyridine nucleotide synthesis was detected in all fern species, although this activity was always less than nicotinic acid glucoside synthesis. Predominant formation of nicotinic acid glucoside is characteristic of nicotinic acid metabolism in ferns. This reaction appears to act as a detoxication mechanism, removing excess nicotinic acid.

  11. FTIR and py-GC-MS spectra of true-fern and seed-fern sphenopterids (Sydney Coalfield, Nova Scotia, Canada, Pennsylvanian)

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2002-01-01

    Sphenopterid specimens from the Late Pennsylvanian of Sydney Coalfield, Canada, are investigated by FTIR and py-GC-MS techniques as part of an on-going research project into the biochemistry and chemotaxonomy of Pennsylvanian-age pteridophylls. Included in the investigation are samples of the true-fern species Oligocarpia brongniartii and Zeilleria delicatula that are preserved as naturally macerated cuticles (NMC), and the seed-fern Eusphenopteris neuropteroides that is also preserved as a compression/impression. FTIR spectra of NMC seed-fern E. neuropteroides, and fern sphenopterid O. brongniartii are very similar, except that the latter does not have aromatic bands in the 700-900 cm-1 out-of-plane region, py-GC-MS show more aromatic compounds for the seed fern than for the two true-fern sphenopterids. Another difference between seed-fern and true-fern sphenopterids is a lower ratio of CH2 to CH3 in chemically treated specimens (CTC) for the seed fern. These observations suggest slightly higher aromaticity for the seed ferns, perhaps related to some chemotaxonomic differences. Comparison of FTIR and py-GC-MS characteristics of sphenopterids and other plant groups shows that these two techniques have potential to identifying chemotaxonomic signals from Carboniferous pteridophylls in general, although more data are needed to confirm this. ?? 2002 Elsevier Science B.V. All rights reserved.

  12. Gene transfer from a parasitic flowering plant to a fern.

    Science.gov (United States)

    Davis, Charles C; Anderson, William R; Wurdack, Kenneth J

    2005-11-07

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps from root-parasitic Loranthaceae. These transgenes are restricted to B. virginianum and occur across the range of the species. Molecular and life-history traits indicate that the transfer preceded the global expansion of B. virginianum, and that the latter may have happened very rapidly. This is the first report of HGT from an angiosperm to a fern, through either direct parasitism or the mediation of interconnecting fungal symbionts.

  13. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    The naturally occurring phytotoxin ptaquiloside (PTA) has long been known to be both acute toxic and carcinogenic. Contents of more than 1% ptaquiloside on dry weight has been detected in bracken (Pteridium spp.), a fern distributed across the globe in often dense populations. This work focused...... fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  14. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  15. Gene silencing in a polyploid homosporous fern: paleopolyploidy revisited.

    OpenAIRE

    Gastony, G J

    1991-01-01

    Because of their high chromosome numbers, homosporous vascular plants were considered paleopolyploids until recent enzyme electrophoretic studies rejected this hypothesis by showing that they express only diploid numbers of isozymes. In polyploid sporophytes of the homosporous fern pelleae rufa, however, progressive diminution of phosphoglucoisomerase activities encoded by one ancestral genome culminates in tetraploid plants exhibiting a completely diploidized electrophoretic phenotype for th...

  16. Ferns and lycophytes of Pernambuco State, Brazil: Metaxyaceae

    Directory of Open Access Journals (Sweden)

    Iva Carneiro Leão Barros

    2010-09-01

    Full Text Available The present paper elucidates part of the fern flora of Pernambuco State. Metaxyaceae is native to the state and is represented by a single species, Metaxya rostrata (Kunth C. Presl. Descriptions and illustrations, as well as geographical distribution and habitats, are presented.

  17. Why are there so few species of ferns?

    Science.gov (United States)

    Ranker, Tom A; Sundue, Michael A

    2015-07-01

    A recent study has documented a natural hybridization event between two fern lineages that last shared a common ancestor about 60 million years ago. This is one of the deepest hybridization events ever described and has important implications for plant speciation theory.

  18. Instructions for collecting tree ferns of the family Cyatheaceae

    NARCIS (Netherlands)

    Holttum, R.E.

    1957-01-01

    The next monographic study which will be undertaken for the series Pteridophyta of the Flora Malesiana will be devoted to the tree ferns of the Cyatheaceae. In connection with the large size of these plants and the desirability of having more and complete material at our disposal, the following note

  19. Comparative morphology of the gametophyte of some Thelypteroid ferns

    NARCIS (Netherlands)

    Sen, Tuhinsri

    1981-01-01

    A study of the development of the gametophytes of sixteen thelypteroid ferns reveals similarities and significant differences among them. Combinations of the diversified features of the prothalli appear to have a tremendous impact on identification and delimitation of the major taxa, and support the

  20. Checklist of the Ferns, Natural Falls State Park

    Directory of Open Access Journals (Sweden)

    Smith, Bruce A.

    2001-12-01

    Full Text Available Natural Falls State Park, formerly known as Dripping Springs is located in northeast Oklahoma. The park's natural beauty and flora have attracted visitors since 1907. In a 1988 visit to the Oklahoma State University Herbarium, I noticed that several herbarium sheets of ferns were collected from Dripping Springs. This was intriguing and made me want to visit the area. Due to my interest in floristics and taxonomy, Natural Falls State Park seemed the perfect place to create a checklist of ferns. Thus, the objective of this study was to create an inventory of the ferns of Dripping Springs using my collection and the collections and observations from earlier botanists. A systematic collection of the ferns of Dripping Springs was conducted on August 7, 1998, October 15, 1998, and October 20, 2001. Using standard taxonomic methods, each plant was identified to species and subsequently inventoried. In three days of collecting, 17species from 6 families and 12 genera were encountered. Since 1925 a total of 19 species from 6 families and 12 genera have been reported to occur.

  1. New observations and synthesis of paleogene heterosporous water ferns

    NARCIS (Netherlands)

    Collinson, M.E.; Smith, S.Y.; van Konijnenburg-van Cittert, J.H.A.; Batten, D.J.; Refidaff, C.; Barke, J.; Marone, F.

    Premise of research. Reproductive structures of modern genera of heterosporous water ferns (Marsileaceae and Salviniaceae) are widespread and abundant in plant mesofossil assemblages from the Paleogene. For Salviniaceae, whole fertile fossil plants give a good understanding of morphology. These

  2. The omnipresent water fern Azolla caroliniana does not contain lignin

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; Leeuw, J.W. de; Reichart, G.-J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  3. A 4000-species dataset provides new insight into the evolution of ferns.

    Science.gov (United States)

    Testo, Weston; Sundue, Michael

    2016-12-01

    Ferns are the second-most diverse lineage of vascular plants on Earth, yet the best-sampled time-calibrated phylogeny of the group to date includes fewer than 5% of global diversity and was published seven years ago. We present a time-calibrated phylogeny that includes nearly half of extant fern diversity. Our results are evaluated in the context of previous studies and the fossil record, and we develop new hypotheses about the radiation of leptosporangiate ferns. We used sequence data from six chloroplast regions for nearly 4000 species of ferns to generate the most comprehensive phylogeny of the group ever published. We calibrate the phylogeny with twenty-six fossils and use an array of phylogenetic methods to resolve phylogenetic relationships, estimate divergence times, and infer speciation, extinction, and net diversification rates. We infer a mid-late Silurian origin for ferns (including horsetails) and an early Carboniferous origin for leptosporangiate ferns. Most derived fern families appeared in the Cretaceous and persisted for millions of years before rapidly diversifying in the Cenozoic. We find no evidence of differential rates of diversification among terrestrial and epiphytic species. Our findings challenge previous hypotheses on the evolutionary history of ferns and present a new paradigm for their Cenozoic radiation. We estimate earlier divergences for most fern lineages than were reported in previous studies and provide evidence of extended persistence of major fern lineages prior to rapid diversification in the last fifty million years.

  4. Leaf evolution in early-diverging ferns: insights from a new fern-like plant from the Late Devonian of China.

    Science.gov (United States)

    Wang, De-Ming; Xu, Hong-He; Xue, Jin-Zhuang; Wang, Qi; Liu, Le

    2015-06-01

    With the exception of angiosperms, the main euphyllophyte lineages (i.e. ferns sensu lato, progymnosperms and gymnosperms) had evolved laminate leaves by the Late Devonian. The evolution of laminate leaves, however, remains unclear for early-diverging ferns, largely represented by fern-like plants. This study presents a novel fern-like taxon with pinnules, which provides new insights into the early evolution of laminate leaves in early-diverging ferns. Macrofossil specimens were collected from the Upper Devonian (Famennian) Wutong Formation of Anhui and Jiangsu Provinces, South China. A standard degagement technique was employed to uncover compressed plant portions within the rock matrix. A new fern-like taxon, SHOUGANGIA BELLA GEN ET SP NOV: , is described and represents an early-diverging fern with highly derived features. It has a partially creeping stem with adventitious roots only on one side, upright primary and secondary branches arranged in helices, tertiary branches borne alternately or (sub)oppositely, laminate and usually lobed leaves with divergent veins, and complex fertile organs terminating tertiary branches and possessing multiple divisions and numerous terminal sporangia. Shougangia bella provides unequivocal fossil evidence for laminate leaves in early-diverging ferns. It suggests that fern-like plants, along with other euphyllophyte lineages, had independently evolved megaphylls by the Late Devonian, possibly in response to a significant decline in atmospheric CO2 concentration. Among fern-like plants, planate ultimate appendages are homologous with laminate pinnules, and in the evolution of megaphylls, fertile organs tend to become complex. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. [Anatomy of six species of Dryopteris ferns (Dryopteridaceae) from Mexico].

    Science.gov (United States)

    Hernández, Victoria; Terrazas, Teresa; Angeles, Guillermo

    2006-12-01

    Rhizome and foliar anatomy of the Mexican Dryopteris Adans. species were studied and compared with other Dryopteridaceae and other fern families to identify anatomical features with diagnostic value. The anatomy of rhizome, stipe, and blade is similar in species of the Dryopteris patula complex. The cells with un-lignified, thickened wall, with cap or U-shape around the meristeles belong to the collenchyma, in contrast with other fern families. Dryopteris wallichiana (Spreng.) Hyl. is anatomically distinguished from the other studied species by having more layers of sclerenchyma and meristeles on the stipe, and by the lack of sclereid nests on the rhizome. Dryopteris rossii C. Chr. and D. maxonii Underw. & C. Chr. are characterized by the presence of crystals on the periphery of rhizome nests. D. maxonni and D. wallichiana lack blade glands.

  6. Efecto diurético agudo de los extractos etanólico y acuoso de Ceratopteris pteridoides (Hook en ratas normales

    Directory of Open Access Journals (Sweden)

    Antistio Aníbal Alviz

    2013-03-01

    Full Text Available Introducción. Ceratopteris pteridoides es un helecho semiacuático de la familia Parkeriacea, ampliamente utilizado en la medicina popular colombiana como diurético y colelitiásico, sobre el cual no existen reportes científicos que avalen su uso popular como diurético. Objetivo. Evaluar el efecto diurético agudo en dosis única y dosis repetidas a corto plazo, de los extractos etanólico y acuoso de C. pteridoides en un modelo in vivo. Materiales y métodos. El extracto etanólico total fue obtenido por maceración de la planta entera de C. pteridoides con etanol y el extracto acuoso fue obtenido por decocción a 60 °C por 15 minutos. Ambos extractos se sometieron a análisis fitoquímico preliminar y estudio histológico posterior a la administración de los extractos durante ocho días consecutivos (1.000 mg/kg. El efecto diurético se evaluó en ratas Wistar, tratadas con los extractos (500 mg/kg, en forma aguda y en dosis repetidas a corto plazo, cuantificando la eliminación de agua y la excreción renal de sodio y potasio por espectrofotometría de absorción atómica y, de cloruros, por titulación mercurimétrica. Resultados. En el modelo agudo, ambos extractos mostraron un significativo efecto diurético y de excreción renal de sodio y potasio en comparación con el control, mientras que con la administración en dosis repetidas a corto plazo mostraron efecto diurético sin eliminación de electrolitos. El estudio histopatológico no sugirió efectos tóxicos hepáticos o renales. Conclusión. Los resultados demuestran la actividad diurética de C. pteridoides y sustentan el uso popular dado a esta planta como diurético en la costa norte colombiana. Se requieren estudios posteriores que permitan aislar e identificar los compuestos responsables de la actividad y los mecanismos de acción involucrados.   doi: http://dx.doi.org/10.7705/biomedica.v33i1.611

  7. A Precious Fern Species Discovered in Jiulong, Sichuan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Supported by the US National Science Foundation and the National Natural Science Foundation of China, a rare and endangered fern, Isoetes hypsophila, was discovered by a Sino-US research team headed by Prof. SUN Hang from the CAS Kunming Institute of Botany (KIB) and Dr. David E. Boufford from Harvard University in a recent trip to Jiulong, Sichuan, during its botanical survey in the Hengduan Mountains in south China. Scientists say the plant is found for the first time in the region.

  8. Variation of desiccation tolerance and longevity in fern spores.

    Science.gov (United States)

    Ballesteros, Daniel; Hill, Lisa M; Walters, Christina

    2017-04-01

    This work contributes to the understanding of plant cell responses to extreme water stress when it is applied at different intensity and duration. Fern spores are used to explore survival at relative humidity (RH)desiccation damage occurs in desiccation tolerant cells, and that it is expressed as a time-dependent response, otherwise known as aging. Copyright © 2017 Elsevier GmbH. All rights reserved.

  9. Morphology, Physiology, and Anatomy of Penny Fern (Drymoglossum phyloselloidesand Its Effect on Cocoa

    Directory of Open Access Journals (Sweden)

    Fitria Yuliasmara

    2013-08-01

    Full Text Available This study aims to determine the anatomy, physiology and morphology of penny fern (Drimoglosum phylloseloides and its effect on cocoa. Morphological observation of penny fern used microscope to observe the roots, stems, leaves and spores. Physiology of penny fern was observed based on number of stomata and stomatal conductance using stomata printing method, while the amount of chlorophyll based on spectrophotometric method and rate of transpiration used cobalt chloride paper. Penny fern anatomy on cross-sectional and longitudinal in roots, stems and leaves. Penny fern growth was observed based the length of tendrils once a week during rainy and dry season. While the effect of penny fern invasion was observed based on variable leaf area with gravimetric method, the cross-section of attacked cacao branch using microtom and microscope and chlorophyll content by chlorophyll meter. Results showed that penny fern is a epiphytic weed which was crassulaceae acid metabolism plants that have the ability to absorb carbon dioxide at night and carry out photosynthesis during the day with closed stomata. Penny ferns reproduce using spores. The growth rate of penny fern 2.18 cm/week during the dry season and while in rainy season 3.89 cm/week. Penny fern leaf contains 0.0212 mg/g chlorophyll. Penny fern stomata density was 18.33/mm 2 with a width of opening stomata at night 26.3 µm which caused a veryslow rate of transpiration of 0.69 mm 2 /seconds. The existence penny fern on cocoa decreased leaf area and chlorophyll content decreased crop productivity which was indicated by decreasing in number of flowers, number of small, medium fruit, and large pods. However it had no effect on the number of leaves on one side flush cocoa. Key words: Drimoglosum phylloseloides, weeds, decrease productivity, Theobroma cacao

  10. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    OpenAIRE

    Brett R Scheffers; Ben L. Phillips; Shoo, Luke P

    2014-01-01

    Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of vario...

  11. The physiological implications of primary xylem organization in two ferns.

    Science.gov (United States)

    Brodersen, Craig R; Roark, Lindsey C; Pittermann, Jarmila

    2012-11-01

    Xylem structure and function are well described in woody plants, but the implications of xylem organization in less-derived plants such as ferns are poorly understood. Here, two ferns with contrasting phenology and xylem organization were selected to investigate how xylem dysfunction affects hydraulic conductivity and stomatal conductance (g(s)). The drought-deciduous pioneer species, Pteridium aquilinum, exhibits fronds composed of 25 to 37 highly integrated vascular bundles with many connections, high g(s) and moderate cavitation resistance (P50 = -2.23 MPa). By contrast, the evergreen Woodwardia fimbriata exhibits sectored fronds with 3 to 5 vascular bundles and infrequent connections, low g(s) and high resistance to cavitation (P50 = -5.21 MPa). Xylem-specific conductivity was significantly higher in P. aqulinium in part due to its wide, efficient conduits that supply its rapidly transpiring pinnae. These trade-offs imply that the contrasting xylem organization of these ferns mirrors their divergent life history strategies. Greater hydraulic connectivity and g(s) promote rapid seasonal growth, but come with the risk of increased vulnerability to cavitation in P. aquilinum, while the conservative xylem organization of W. fimbriata leads to slower growth but greater drought tolerance and frond longevity.

  12. Limitation of distribution of two rare ferns in fragmented landscape

    Science.gov (United States)

    Tájek, Přemysl; Bucharová, Anna; Münzbergová, Zuzana

    2011-09-01

    Species distribution in the landscape is limited either by 1. diaspore production, dispersal and establishment abilities or 2. by availability of suitable habitats; 3. or by a combination of both factors. The relative importance of these factors is species-dependent and has mainly been studied for seed plants. We studied the importance of habitat and dispersal limitation for distribution of two rare fern species, Asplenium adulterinum and Asplenium cuneifolium, restricted to serpentine rocks, using analysis of their distribution on a regional scale (several kilometers). Within the model region, all 98 serpentine rocks were mapped. We used data on abiotic characteristics and on the presence of all vascular plant species on the rocks to predict which of the rocks were suitable for the two Asplenium species. Suitable habitats were positively defined mainly by the presence of appropriate microhabitats and the height of the highest rock, which represents the size of space with lowered concurrence. Other determinants of habitat suitability differed between species. Neither species occupied all suitable localities, indicating dispersal limitation. Locality isolation significantly affected one of the species but not the other. Overall, the results suggest that both fern species have suitable but unoccupied localities in the region and demonstrates that ferns, similar to seed plants, are limited by their dispersal ability in the landscape.

  13. Global phylogeny and biogeography of grammitid ferns (Polypodiaceae).

    Science.gov (United States)

    Sundue, Michael A; Parris, Barbara S; Ranker, Tom A; Smith, Alan R; Fujimoto, Erin L; Zamora-Crosby, Delia; Morden, Clifford W; Chiou, Wen-Liang; Chen, Cheng-Wei; Rouhan, Germinal; Hirai, Regina Y; Prado, Jefferson

    2014-12-01

    We examined the global historical biogeography of grammitid ferns (Polypodiaceae) within a phylogenetic context. We inferred phylogenetic relationships of 190 species representing 31 of the 33 currently recognized genera of grammitid ferns by analyzing DNA sequence variation of five plastid DNA regions. We estimated the ages of cladogenetic events on an inferred phylogeny using secondary fossil calibration points. Historical biogeographical patterns were inferred via ancestral area reconstruction. Our results supported four large-scale phylogenetic and biogeographic patterns: (1) a monophyletic grammitid clade that arose among Neotropical polypod ancestors about 31.4 Ma; (2) a paraphyletic assemblage of clades distributed in the Neotropics and the Afro-Malagasy region; (3) a large clade distributed throughout the Asia-Malesia-Pacific region that originated about 23.4 Ma; and, (4) an Australian or New Zealand origin of the circumaustral genus Notogrammitis. Most genera were supported as monophyletic except for Grammitis, Oreogrammitis, Radiogrammitis, and Zygophlebia. Grammitid ferns are a well-supported monophyletic group with two biogeographically distinct lineages: a primarily Neotropical grade exhibiting several independent successful colonizations to the Afro-Malagasy region and a primarily Paleotropical clade exhibiting multiple independent dispersals to remote Pacific islands and temperate, austral regions.

  14. Sorption equilibrium of mercury onto ground-up tree fern

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Y.-S. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)], E-mail: ysho@isu.edu.tw; Wang, C.-C. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)

    2008-08-15

    The sorption behavior of mercury at different temperatures onto ground-up tree fern was investigated. The experimental results were fitted to two two-parameter isotherms, the Freundlich and Langmuir isotherms, as well as to two three-parameter isotherms, the Redlich-Peterson and Sips isotherms to obtain the characteristic parameters of each model. A comparison of best-fitting was performed using the coefficient of determination and Chi-square test. Both the Langmuir and Redlich-Peterson isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of mercury ions onto ground-up tree fern was 26.5 mg/g at 298 K. It was noted that an increase in temperature resulted in a higher mercury ion loading per unit weight of the tree fern. In addition, various thermodynamic parameters, such as {delta}G{sup o}, {delta}H{sup o}, and {delta}S{sup o}, were calculated and compared with the sorption of mercury by other sorbents.

  15. Structure-function constraints of tracheid-based xylem: a comparison of conifers and ferns.

    Science.gov (United States)

    Pittermann, Jarmila; Limm, Emily; Rico, Christopher; Christman, Mairgareth A

    2011-10-01

    The ferns comprise one of the most ancient tracheophytic plant lineages, and occupy habitats ranging from tundra to deserts and the equatorial tropics. Like their nearest relatives the conifers, modern ferns possess tracheid-based xylem but the structure-function relationships of fern xylem are poorly understood. Here, we sampled the fronds (megaphylls) of 16 species across the fern phylogeny, and examined the relationships among hydraulic transport, drought-induced cavitation resistance, the xylem anatomy of the stipe, and the gas-exchange response of the pinnae. For comparison, the results are presented alongside a similar suite of conifer data. Fern xylem is as resistant to cavitation as conifer xylem, but exhibits none of the hydraulic or structural trade-offs associated with resistance to cavitation. On a conduit diameter basis, fern xylem can exhibit greater hydraulic efficiency than conifer and angiosperm xylem. In ferns, wide and long tracheids compensate in part for the lack of secondary xylem and allow ferns to exhibit transport rates on a par with those of conifers. We suspect that it is the arrangement of the primary xylem, in addition to the intrinsic traits of the conduits themselves, that may help explain the broad range of cavitation resistance in ferns.

  16. Random ferns method implementation for the general-purpose machine learning

    CERN Document Server

    Kursa, Miron B

    2012-01-01

    In this paper I present an extended implementation of the Random ferns algorithm contained in the R package rFerns. It differs from the original by the ability of consuming categorical and numerical attributes instead of only binary ones. Also, instead of using simple attribute subspace ensemble it employs bagging and thus produce error approximation and variable importance measure modelled after Random forest algorithm. I also present benchmarks' results which show that although Random ferns' accuracy is mostly smaller than achieved by Random forest, its speed and good quality of importance measure it provides make rFerns a reasonable choice for a specific applications.

  17. Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.

    Science.gov (United States)

    Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns.

  18. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    Science.gov (United States)

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.

  19. A progress report on the work toward propagation and reintroduction of the threatened plant American Hart's Tongue Fern (Phyllitis scolopendrium)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report describes efforts to propogate the fern spores in the lab. Attempts to propagate the spores from the Am. Hart's Tongue Fern in the Lab is reviewed. Spores...

  20. Spatial Characteristics of Edible Wild Fern Harvesting in Mountainous Villages in Northeastern Japan Using GPS Tracks

    Directory of Open Access Journals (Sweden)

    Toshiya Matsuura

    2014-02-01

    Full Text Available Wild plants in forests provide valuable living resources for rural communities. The location where local people harvest various species is important to the wise use of forest ecosystem services. Using global positioning system (GPS tracking of harvesters’ activities as well as geographic information system (GIS and a generalized linear model (GLM, this study analyzed the spatial differences among harvesting sites of three popular edible ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous villages of Northeastern Japan. The explanatory variables used were vegetation classes, terrain features, and proximity to roadways. The GLM yielded clear differences in harvesting sites among species that were affected by both the species’ ecological characteristics and human behavior. Ostrich fern was harvested mainly in canopy openings along valley floors, whereas royal fern harvest sites were frequently located in snow avalanche scrublands. Bracken was mainly harvested in deforested areas or young conifer plantations. Whereas ostrich fern and bracken harvest sites were restricted by the accessibility from roadways, this was not the case for royal fern. Potential harvest sites of ferns were estimated with the highest value for bracken. Our results suggest that local harvesters seriously consider various natural and anthropogenic factors to maintain effective and sustainable harvesting.

  1. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats.

  2. Ancestral stomatal control results in a canalization of fern and lycophyte adaptation to drought.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2013-04-01

    Little is known about how a predominantly passive hydraulic stomatal control in ferns and lycophytes might impact water use under stress. Ferns and lycophytes occupy a diverse array of habitats, from deserts to rainforest canopies, raising the question of whether stomatal behaviour is the same under all ecological strategies and imposes ecological or functional constraints on ferns and lycophytes. We examined the stomatal response of a diverse sample of fern and lycophyte species to both soil and atmospheric water stress, assessing the foliar level of the hormone abscisic acid (ABA) over drought and recovery and the critical leaf water potential (Ψl) at which photosynthesis in droughted leaves failed to recover. The stomata of all ferns and lycophytes showed very predictable responses to soil and atmospheric water deficit via Ψl, while stomatal closure was poorly correlated with changes in ABA. We found that all ferns closed stomata at very low levels of water stress and their survival afterwards was limited only by their capacitance and desiccation tolerance. Ferns and lycophytes have constrained stomatal responses to soil and atmospheric water deficit as a consequence of a predominantly passive stomatal regulation. This results in a monotypic strategy in ferns and lycophytes under water stress.

  3. Field Guide to Northeastern Ferns. New York State Museum Bulletin Number 444.

    Science.gov (United States)

    Ogden, Eugene C.

    This guide was developed for use by individuals with little or no botanical training who wish to identify native ferns of New York, New England, New Jersey, and Pennsylvania. A random access key, developed by the author, provides multiple pathways for identification of 60 species in 29 genera of ferns. (CS)

  4. The mucilage secreting hairs on the young fronds of some Leptosporangiate Ferns

    NARCIS (Netherlands)

    Hennipman, E.

    1968-01-01

    During a collecting trip to Thailand, as a member of the Thai-Dutch botanical expedition 1965/1966, I was struck by the excessive amount of mucilage sometimes present on the circinnate fronds of several leptosporangiate ferns. This was especially evident in representatives of the monotypic fern fami

  5. Klukiopsis jurassica——A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    邓胜徽[1; 王仕俊[2

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  6. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Science.gov (United States)

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper (Lygodium flexuosum (Linnaeus) Swartz) to the list of terrestrial noxious weeds...

  7. The effect of nitrogen additions on bracken fern and its insect herbivores at sites with high and low atmospheric pollution

    Science.gov (United States)

    M.E. Jones; M.E. Fenn; T.D. Paine

    2011-01-01

    The impact of atmospheric pollution, including nitrogen deposition, on bracken fern herbivores has never been studied. Bracken fern is globally distributed and has a high potential to accumulate nitrogen in plant tissue. We examined the response of bracken fern and its herbivores to N fertilization at a high and low pollution site in forests downwind of Los Angeles,...

  8. In Vitro Conservation of Some Threatened and Economically Important Ferns Belonging to the Indian Subcontinent

    Directory of Open Access Journals (Sweden)

    Shastri P. Shukla

    2014-01-01

    Full Text Available This study was undertaken to identify methods of mass multiplication for five ornamental, economically important ferns (Nephrolepis biserrata (Sw. Schott., N. cordifolia cv. ‘‘duffii’’ (L. Presl., N. exaltata cv. bostoniensis (L. Schott., Pteris vittata L., and Cyclosorus dentatus Link., and three threatened ferns, namely, Cyathea spinulosa Wall. ex. Hook, Pityrogramma calomelanos (L. Link., and Microsorum punctatum (L. Schott., through in vitro techniques. Collections were made from different biodiversity zones of India including Northeast Himalayas, Kumaon Himalayas, and Western Ghat and successfully introduced and grown in a fern-house. Aseptic cultures were raised at the morphogenic level of callus, axillary shoot, multiple shoot, and rooted plants. An optimized medium is described for each fern species. Plantlets were also produced from spore culture of Cyathea spinulosa and successfully hardened under fern house conditions.

  9. Crowdfunding the Azolla fern genome project: a grassroots approach.

    Science.gov (United States)

    Li, Fay-Wei; Pryer, Kathleen M

    2014-01-01

    Much of science progresses within the tight boundaries of what is often seen as a "black box". Though familiar to funding agencies, researchers and the academic journals they publish in, it is an entity that outsiders rarely get to peek into. Crowdfunding is a novel means that allows the public to participate in, as well as to support and witness advancements in science. Here we describe our recent crowdfunding efforts to sequence the Azolla genome, a little fern with massive green potential. Crowdfunding is a worthy platform not only for obtaining seed money for exploratory research, but also for engaging directly with the general public as a rewarding form of outreach.

  10. A Gompertz regression model for fern spores germination

    Directory of Open Access Journals (Sweden)

    Gabriel y Galán, Jose María

    2015-06-01

    Full Text Available Germination is one of the most important biological processes for both seed and spore plants, also for fungi. At present, mathematical models of germination have been developed in fungi, bryophytes and several plant species. However, ferns are the only group whose germination has never been modelled. In this work we develop a regression model of the germination of fern spores. We have found that for Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei and Polypodium feuillei species the Gompertz growth model describe satisfactorily cumulative germination. An important result is that regression parameters are independent of fern species and the model is not affected by intraspecific variation. Our results show that the Gompertz curve represents a general germination model for all the non-green spore leptosporangiate ferns, including in the paper a discussion about the physiological and ecological meaning of the model.La germinación es uno de los procesos biológicos más relevantes tanto para las plantas con esporas, como para las plantas con semillas y los hongos. Hasta el momento, se han desarrollado modelos de germinación para hongos, briofitos y diversas especies de espermatófitos. Los helechos son el único grupo de plantas cuya germinación nunca ha sido modelizada. En este trabajo se desarrolla un modelo de regresión para explicar la germinación de las esporas de helechos. Observamos que para las especies Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei y Polypodium feuillei el modelo de crecimiento de Gompertz describe satisfactoriamente la germinación acumulativa. Un importante resultado es que los parámetros de la regresión son independientes de la especie y que el modelo no está afectado por variación intraespecífica. Por lo tanto, los resultados del trabajo muestran que la curva de Gompertz puede representar un modelo general para todos los helechos leptosporangiados

  11. Effect of synthetic detergents on germination of fern spores

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  12. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qing Lan [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); School of Electronics and Information, Nantong University, Jiangsu 226019 (China); Xiong, Rui [School of Physics and Technology, Wuhan University, Hubei 430072 (China); Zhai, Bao-gai [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China)

    2015-01-01

    Graphical abstract: - Highlights: • Fern-like ZnO nanoleaves were synthesized by ultrasonicating Zn microcrystals in water. • A fern-like ZnO nanoleaf is a self-assembly of ZnO nanoplates along one ZnO nanorod. • Fern-like ZnO nanoleaves exhibit enhanced photocatalytic activity than ZnO nanocrystals. • The branched hierarchical structures are responsible for the enhanced photocatalytic activity. - Abstract: Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet–visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  13. Mangrove associated lignite beds of Malvan, Konkan: Evidence for higher sea-level during the Late Tertiary (Neogene) along the west coast of India

    Energy Technology Data Exchange (ETDEWEB)

    Kumaran, K.P.N.; Shindikar, M.; Limaye, R.B. [Agharkar Research Inst., Pune (India)

    2004-01-25

    Fossil pneumatophores (breathing roots) of Avicennia are recovered and reported from the lignite beds exposed in Kolamb well-section near Malvan, Konkan area of western Maharashtra. The accrued palynoflora is dominated by mangroves (Avicennia, Aegialitis, Excoecaria, Rhizophora and Sonneratia). The spores of mangrove fern (Acrostichum aureum) an estuarine fungus Cirrenalia indicate that these lignites are autochthonous and deposited in a near-shore environment. Presence of foraminiferal linings (= microforaminifera), dinoflagellate cysts, a few calcareous nannofossils and scolecodonts is an irrefutable proof of marine and brackish water influence during the deposition of lignites under intertidal/tidal swampy condition (mangrove influenced) with fair input from freshwater swamps and hinterland. Freshwater-related forms, viz. Ceratopteris thalictroides, Nymphaeaceae, Ctenolophonaceae and hinterland taxa (Cullenia/Durio) of Bombacaceae along with abundance of microthyriaceous fungi in the palynoflora imply a warm humid tropical climate with high precipitation during the depositional period. The presence of Ctenolophon englerianus (= Ctenolophonidites costatus) in Kolamb lignites suggests the Late Neogene (Late Miocene-Early Pliocene) age. The occurrence of pneumatophores and associated lignite deposits about 37 m above the present mean sea-level, and much inland, clearly indicates the higher sea-level strand during Late Neogene along the west coast of India.

  14. Evolution of leaf form in marsileaceous ferns: evidence for heterochrony.

    Science.gov (United States)

    Pryer, Kathleen M; Hearn, David J

    2009-02-01

    Using an explicit phylogenetic framework, ontogenetic patterns of leaf form are compared among the three genera of marsileaceous ferns (Marsilea, Regnellidium, and Pilularia) with the outgroup Asplenium to address the hypothesis that heterochrony played a role in their evolution. We performed a Fourier analysis on a developmental sequence of leaves from individuals of these genera. Principal components analysis of the harmonic coefficients was used to characterize the ontogenetic trajectories of leaf form in a smaller dimensional space. Results of this study suggest that the "evolutionary juvenilization" observed in these leaf sequences is best described using a mixed model of heterochrony (accelerated growth rate and early termination at a simplified leaf form). The later stages of the ancestral, more complex, ontogenetic pattern were lost in Marsileaceae, giving rise to the simplified adult leaves of Marsilea, Regnellidium, and Pilularia. Life-history traits such as ephemeral and uncertain habitats, high reproductive rates, and accelerated maturation, which are typical for marsileaceous ferns, suggest that they may be "r strategists." The evidence for heterochrony presented here illustrates that it has resulted in profound ecological and morphological consequences for the entire life history of Marsileaceae.

  15. Development of the gametophyte of the fern Schizaea pusilla

    Science.gov (United States)

    Kiss, J. Z.; Swatzell, L. J.

    1996-01-01

    Schizaea pusilla is a pteridophyte with several unique developmental characteristics. In contrast to most other fern species, S. pusilla gametophytes remain filamentous throughout their development, and the gametophytes are associated with an endophytic fungus which appears to be mycorrhizal. In terms of tropistic responses, apical filament cells of young gametophytes are negatively phototropic compared with germ filaments of other ferns which exhibit positive phototropism. Cryofixation (propane jet freezing and high-pressure freezing) in conjunction with freeze substitution electron microscopy was used to study young gametophytes. The results demonstrate that apical filament cells have a distinctive structural polarity and that rhizoids also can be successfully frozen by these methods. The cytoskeleton and endomembrane system were particularly well preserved in cryofixed cells. In addition, Schizaea gametophytes were used as a test system to evaluate potential artifacts of propane jet freezing and high pressure freezing. There was little apparent difference in ultrastructure between cells cryofixed by either freezing method. These gametophytes will be useful in determining the effectiveness of cryofixation techniques and as a model system in tip growth studies.

  16. A free-access online key to identify Amazonian ferns

    Directory of Open Access Journals (Sweden)

    Gabriela Zuquim

    2017-03-01

    Full Text Available There is urgent need for more data on species distributions in order to improve conservation planning. A crucial but challenging aspect of producing high-quality data is the correct identification of organisms. Traditional printed floras and dichotomous keys are difficult to use for someone not familiar with the technical jargon. In poorly known areas, such as Amazonia, they also become quickly outdated as new species are described or ranges extended. Recently, online tools have allowed developing dynamic, interactive, and accessible keys that make species identification possible for a broader public. In order to facilitate identifying plants collected in field inventories, we developed an internet-based free-access tool to identify Amazonian fern species. We focused on ferns, because they are easy to collect and their edaphic affinities are relatively well known, so they can be used as an indicator group for habitat mapping. Our key includes 302 terrestrial and aquatic entities mainly from lowland Amazonian forests. It is a free-access key, so the user can freely choose which morphological features to use and in which order to assess them. All taxa are richly illustrated, so specimens can be identified by a combination of character choices, visual comparison, and written descriptions. The identification tool was developed in Lucid 3.5 software and it is available at http://keyserver.lucidcentral.org:8080/sandbox/keys.jsp.

  17. Invariant Hough Random Ferns for Object Detection and Tracking

    Directory of Open Access Journals (Sweden)

    Yimin Lin

    2014-01-01

    Full Text Available This paper introduces an invariant Hough random ferns (IHRF incorporating rotation and scale invariance into the local feature description, random ferns classifier training, and Hough voting stages. It is especially suited for object detection under changes in object appearance and scale, partial occlusions, and pose variations. The efficacy of this approach is validated through experiments on a large set of challenging benchmark datasets, and the results demonstrate that the proposed method outperforms state-of-the-art conventional methods such as bounding-box-based and part-based methods. Additionally, we also propose an efficient clustering scheme based on the local patches’ appearance and their geometric relations that can provide pixel-accurate, top-down segmentations from IHRF back-projections. This refined segmentation can be used to improve the quality of online object tracking because it avoids the drifting problem. Thus, an online tracking framework based on IHRF, which is trained and updated in each frame to distinguish and segment the object from the background, is established. Finally, the experimental results on both object segmentation and long-term object tracking show that this method yields accurate and robust tracking performance in a variety of complex scenarios, especially in cases of severe occlusions and nonrigid deformations.

  18. Ecological and evolutionary consequences of desiccation tolerance in tropical fern gametophytes.

    Science.gov (United States)

    Watkins, James E; Mack, Michelle C; Sinclair, Thomas R; Mulkey, Stephen S

    2007-01-01

    Ferns have radiated into the same diverse environments as spermatophytes, and have done so with an independent gametophyte that is not protected by the parent plant. The degree and extent of desiccation tolerance (DT) in the gametophytes of tropical fern species was assessed to understand mechanisms that have allowed ferns to radiate into a diversity of habitats. Species from several functional groups were subjected to a series of desiccation events, including varying degrees of intensity and multiple desiccation cycles. Measurements of chlorophyll fluorescence were used to assess recovery ability and compared with species ecology and gametophyte morphology. It is shown that vegetative DT (rare in vascular plants) is widely exhibited in fern gametophytes and the degree of tolerance is linked to species habitat preference. It is proposed that gametophyte morphology influences water-holding capacity, a novel mechanism that may help to explain how ferns have radiated into drought-prone habitats. Fern gametophytes have often been portrayed as extreme mesophytes with little tolerance for desiccation. The discovery of DT in gametophytes holds potential for improving our understanding of both the controls on fern species distribution and their evolution. It also advances a new system with which to study the evolution of DT in vascular plants.

  19. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Science.gov (United States)

    Ma, Qing Lan; Xiong, Rui; Zhai, Bao-gai; Huang, Yuan Ming

    2015-01-01

    Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet-visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  20. Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

    Science.gov (United States)

    Funk, Jennifer L; Amatangelo, Kathryn L

    2013-09-01

    Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

  1. Horizontal transfer of an adaptive chimeric photoreceptor from bryophytes to ferns.

    Science.gov (United States)

    Li, Fay-Wei; Villarreal, Juan Carlos; Kelly, Steven; Rothfels, Carl J; Melkonian, Michael; Frangedakis, Eftychios; Ruhsam, Markus; Sigel, Erin M; Der, Joshua P; Pittermann, Jarmila; Burge, Dylan O; Pokorny, Lisa; Larsson, Anders; Chen, Tao; Weststrand, Stina; Thomas, Philip; Carpenter, Eric; Zhang, Yong; Tian, Zhijian; Chen, Li; Yan, Zhixiang; Zhu, Ying; Sun, Xiao; Wang, Jun; Stevenson, Dennis W; Crandall-Stotler, Barbara J; Shaw, A Jonathan; Deyholos, Michael K; Soltis, Douglas E; Graham, Sean W; Windham, Michael D; Langdale, Jane A; Wong, Gane Ka-Shu; Mathews, Sarah; Pryer, Kathleen M

    2014-05-06

    Ferns are well known for their shade-dwelling habits. Their ability to thrive under low-light conditions has been linked to the evolution of a novel chimeric photoreceptor--neochrome--that fuses red-sensing phytochrome and blue-sensing phototropin modules into a single gene, thereby optimizing phototropic responses. Despite being implicated in facilitating the diversification of modern ferns, the origin of neochrome has remained a mystery. We present evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in our large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 Mya, long after the split between the two plant lineages (at least 400 Mya). By analyzing the draft genome of the hornwort Anthoceros punctatus, we also discovered a previously unidentified phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was transferred horizontally to ferns, where it may have played a significant role in the diversification of modern ferns.

  2. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  3. THE DIVERSITY OF EPIPHYTIC FERN ON THE OIL PALM TREE (Elaeis guineensis Jacq. IN PEKANBARU, RIAU

    Directory of Open Access Journals (Sweden)

    Nery Sofiyanti

    2015-02-01

    Full Text Available Oil palm (Elaeis guineensis is one  main commodity in Riau Province. Morphologically, the trunk of oil palm  has suitable environment for the growth of epiphytic fern, due to its broaden base of petiole that may accumulate organic and anorganic debrish. The objective of this study was to investigate the diversity of epiphytic fern on the oil palm tree. A total of 125 oil palm trees from seven  study sites in Pekanbaru, Riau were observed. The number of epiphytic ferns identified in this study was 16 species belongs to six families.

  4. Water-clover ferns, Marsilea, in the Southeastern United States

    Science.gov (United States)

    Jacono, Colette C.; Johnson, David M.

    2006-01-01

    A surge in the collection of exotic Marsilea, M. mutica, M. minuta and M. hirsuta in the southeastern United States has prompted the need for updated identification aids. This study provides an annotated key to all water-clover ferns occurring in the region. It describes and illustrates recently documented exotic species and a previously misidentified western introduction. It details the rediscovery of M. ancylopoda, presumed extinct, and confirms its identification as the western species M. oligospora. Finally it clarifies the status and distribution of two additional western North American species introduced to the southeast, M. vestita and M. macropoda.

  5. 美国紧急修补Fern Ridge坝

    Institute of Scientific and Technical Information of China (English)

    郑国良; 范友军

    2005-01-01

    俄勒冈州正在从美国联邦政府寻求4200万美元的紧急资金以修补Fem Ridge坝。2004年12月,美国陆军工程师团(USACE)将大坝的库水位降低了13.5m。降低库水位是由于发现有越来越多的泥沙从大坝的渗流集水沟流出。一个由USACE召集的独立调查委员会得出结论说,因管涌和/或内部侵蚀的原因,63a坝龄的Fern Ridge坝正处于溃坝的活跃状态,水库水位高程应当限制在110m以下,

  6. Macedonio Fernández: la forma de la experiencia

    Directory of Open Access Journals (Sweden)

    Mónica Bueno

    2015-10-01

    Full Text Available Podemos supor que, Macedonio Fernández, escritor da vanguardia argentina, constrói uma noção de experiência que descreve de uma maneira singular a relação vida/literatura. Museo de la Novela de la Eterna, sua novela “boa” (assim ele a chamava, não só narra a tensão entre o real e o ficcional senão que é um procedimento básico de construção do não-real, do que ainda não é, no sentido blochiano, e o conhecimento da experiência de Macedonio parece funcionar nessa perspectiva utópica.

  7. Application of Random Ferns for non-planar object detection

    Science.gov (United States)

    Mastov, Alexey; Konovalenko, Ivan; Grigoryev, Anton

    2015-12-01

    The real time object detection task is considered as a part of a project devoted to development of autonomous ground robot. This problem has been successfully solved with Random Ferns algorithm, which belongs to keypoint-based method and uses fast machine learning algorithms for keypoint matching step. As objects in the real world are not always planar, in this article we describe experiments of applying this algorithm for non-planar objects. Also we introduce a method for fast detection of a special class of non-planar objects | those which can be decomposed into planar parts (e.g. faces of a box). This decomposition needs one detector for each side, which may significantly affect speed of detection. Proposed approach copes with it by omitting repeated steps for each detector and organizing special queue of detectors. It makes the algorithm three times faster than naive one.

  8. The fern cavitation catapult: mechanism and design principles.

    Science.gov (United States)

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  9. Phylogeny and historical biogeography of the lastreopsid ferns (Dryopteridaceae).

    Science.gov (United States)

    Labiak, Paulo H; Sundue, Michael; Rouhan, Germinal; Hanks, Judith G; Mickel, John T; Moran, Robbin C

    2014-07-01

    • Premise of the study: As currently circumscribed, Lastreopsis has about 45 species and occurs in Australia, southern Asia, Africa, Madagascar, and the neotropics. Previous molecular phylogenetic studies suggested that Lastreopsis is paraphyletic. Our study focuses on resolving relationships among the lastreopsid ferns (Lastreopsis, Megalastrum, and Rumohra), the evolution of morphological characters, and an understanding of the temporal and spatial patterns that have led to the current diversity and geographical distribution of its extant species.• Methods: Phylogenetic relationships were recovered under Bayesian, maximum likelihood, and maximum parsimony methods, using a data set of four plastid markers. Divergence time estimates were made using BEAST, and the biogeographic hypotheses were tested under the DEC model and the RASP/S-DIVA methods.• Key results: Lastreopsis was recovered as paraphyletic, and at least one of its clades should be recognized as a distinct genus, Parapolystichum. Coveniella poecilophlebia and Oenotrichia tripinnata were nested within Lastreopsis s.s., Megalastrum and Rumohra as sister to the Lastreopsis s.s., and the Lastreopsis amplissima clades. The initial diversification of the lastreopsids took place at about 56.55 Ma, from a neotropical ancestor.• Conclusions: Taxonomic recognition of Parapolystichum is warranted to preserve the monophyly of Lastreopsis. Diversification among the main clades of the lastreopsid ferns was influenced by climatic and geological changes in the southern hemisphere. The biogeographic history of the group is intimately related to the trans-Antarctic corridor between Australia and South America, with evidence for multiple lineage interchanges between Australia and South America during the Oligocene and the Eocene epochs.

  10. Management plan for the Aleutian shield fern on Adak Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endangered Aleutian shield fern, Polystichum aleuticum is known from only two locations, Atka and Adak islands in the Aleutian Islands, Alaska (Lipkin 1985),...

  11. New combinations of the fern genus Tectaria (Tectariaceae) for the Flora of China.

    OpenAIRE

    Christenhusz, Maarten

    2010-01-01

    For studies on the fern family Tectariaceae for the Flora of China, four species previously treated as Ctenitopsis need new combinations in Tectaria. The new combinations are proposed here and information on their types is provided.

  12. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2014 and 2015 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Fern Cave NWR between 2014 and 2015. Calls were classified using Bat Call ID ([BCID] version 2.5a)...

  13. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012-2013 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012 and 2013. Calls were classified using Bat Call ID ([BCID] version 2.5a) software...

  14. Mobile Acoustical Bat Monitoring Summary Report 2012 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012. Calls were classified using EchoClass(v1.1) software, but classification of...

  15. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern

    Science.gov (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.

    2015-01-01

    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  16. Stable detection of expanded target by the use of boosting random ferns

    Science.gov (United States)

    Deng, Li; Wang, Chunhong; Rao, Changhui

    2012-10-01

    This paper studies the problem of keypoints recognition of extended target which lacks of texture information, and introduces an approach of stable detection of these targets called boosting random ferns (BRF). As common descriptors in this circumstance do not work as well as usual cases, matching of keypoints is hence turned into classification task so as to make use of the trainable characteristic of classifier. The kernel of BRF is consisted of random ferns as the classifier and AdaBoost (Adaptive Boosting) as the frame so that accuracy of random ferns classifier can be boosted to a relatively high level. Experiments compare BRF with widely used SURF descriptor and single random ferns classifier. The result shows that BRF obtains higher recognition rate of keypoints. Besides, for image sequence, BRF provides stronger stability than SURF in target detection, which proves the efficiency of BRF aiming to extended target which lacks of texture information.

  17. TWO ALKYLATED FLAVONOID ISOLATED FROM THE STEM OF THE FERN Chingia sakayensis (Zeiller Holtt

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    Suyatno Suyatno

    2010-06-01

    Full Text Available Two known alkylated flavonoid namely matteucinol dan matteucinol-7-O-b-D-glucoside was isolated for the first time from the fern Chingia sakayensis (Zeiller Holtt's stem. Their structures were elucidated on the basis of spectroscopic evidence and by comparation with those reported data in literature.   Keywords: Fern, Chingia sakayensis, stem, alkylated flavonoid, matteucinol, matteucinol-7-O-b-D-glucoside

  18. Transcriptome-mining for single-copy nuclear markers in ferns.

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    Carl J Rothfels

    Full Text Available BACKGROUND: Molecular phylogenetic investigations have revolutionized our understanding of the evolutionary history of ferns-the second-most species-rich major group of vascular plants, and the sister clade to seed plants. The general absence of genomic resources available for this important group of plants, however, has resulted in the strong dependence of these studies on plastid data; nuclear or mitochondrial data have been rarely used. In this study, we utilize transcriptome data to design primers for nuclear markers for use in studies of fern evolutionary biology, and demonstrate the utility of these markers across the largest order of ferns, the Polypodiales. PRINCIPAL FINDINGS: We present 20 novel single-copy nuclear regions, across 10 distinct protein-coding genes: ApPEFP_C, cryptochrome 2, cryptochrome 4, DET1, gapCpSh, IBR3, pgiC, SQD1, TPLATE, and transducin. These loci, individually and in combination, show strong resolving power across the Polypodiales phylogeny, and are readily amplified and sequenced from our genomic DNA test set (from 15 diploid Polypodiales species. For each region, we also present transcriptome alignments of the focal locus and related paralogs-curated broadly across ferns-that will allow researchers to develop their own primer sets for fern taxa outside of the Polypodiales. Analyses of sequence data generated from our genomic DNA test set reveal strong effects of partitioning schemes on support levels and, to a much lesser extent, on topology. A model partitioned by codon position is strongly favored, and analyses of the combined data yield a Polypodiales phylogeny that is well-supported and consistent with earlier studies of this group. CONCLUSIONS: The 20 single-copy regions presented here more than triple the single-copy nuclear regions available for use in ferns. They provide a much-needed opportunity to assess plastid-derived hypotheses of relationships within the ferns, and increase our capacity to

  19. The microsoroid ferns: Inferring the relationships of a highly diverse lineage of Paleotropical epiphytic ferns (Polypodiaceae, Polypodiopsida).

    Science.gov (United States)

    Kreier, Hans-Peter; Zhang, Xian-Chun; Muth, Heiko; Schneider, Harald

    2008-09-01

    The relationships of the microsoroid ferns were studied using a DNA sequence-based phylogenetic approach. Nucleotide sequences for up to four chloroplast genome regions were assembled for 107 samples from 87 species. Microsoroids s.l. include six lineages of which two are species rich. The results indicate that several genera are not monophyletic (e.g. Microsorum), several controversial genera are confirmed to be monophyletic (e.g. Leptochilus), and some genera new to science should be recognized (M. membranaceum clade). Unique insights were gained into the biogeographic history of this highly diverse epiphytic vascular plant lineage that is widespread in continental Asia to Australasia. Evidence was found for splits into lineages diversifying in parallel in continental Asia and Malesia. No evidence was recovered for an African radiation because all African microsoroid species either also are found in Asia or have sister species in continental Asia. In contrast, evidence for independent radiations were discovered for the Australasian region.

  20. On the widespread capacity for, and functional significance of, extreme inbreeding in ferns.

    Science.gov (United States)

    Sessa, Emily B; Testo, Weston L; Watkins, James E

    2016-08-01

    Homosporous vascular plants utilize three different mating systems, one of which, gametophytic selfing, is an extreme form of inbreeding only possible in homosporous groups. This mating system results in complete homozygosity in all progeny and has important evolutionary and ecological implications. Ferns are the largest group of homosporous land plants, and the significance of extreme inbreeding for fern evolution has been a subject of debate for decades. We cultured gametophytes in the laboratory and quantified the relative frequencies of sporophyte production from isolated and paired gametophytes, and examined associations between breeding systems and several ecological and evolutionary traits. The majority of fern species studied show a capacity for gametophytic selfing, producing sporophytes from both isolated and paired gametophytes. While we did not follow sporophytes to maturity to investigate potential detrimental effects of homozygosity at later developmental stages, our results suggest that gametophytic selfing may have greater significance for fern evolution and diversification than has previously been realized. We present evidence from the largest study of mating behavior in ferns to date that the capacity for extreme inbreeding is prevalent in this lineage, and we discuss its implications and relevance and make recommendations for future studies of fern mating systems.

  1. Mycorrhizae increase arsenic uptake by the hyperaccumulator Chinese brake fern (Pteris vittata L.).

    Science.gov (United States)

    Al Agely, Abid; Sylvia, David M; Ma, Lena Q

    2005-01-01

    Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account.

  2. Terrestrial Invertebrate Arsenic Accumulation Associated With an Arsenic Hyperaccumulating Fern, Pteris vittata (Polypodiales: Pteridaceae).

    Science.gov (United States)

    Jaffe, B D; Ketterer, M E; Hofstetter, R W

    2016-10-01

    Arsenic (As) can play an important role in the contamination of soils, waters, and air. The toxicity of As to most organisms is well established, but little is known about the interactions between environmental As and terrestrial invertebrates and the fate of As through trophic levels. Pteris vittata L. (Polypodiales: Pteridaceae), a fern that hyperaccumulates arsenic, serves as a potential mechanism to facilitate interactions between environmental arsenic and other biota. We compared invertebrate arsenic concentrations (hereafter as [As]) and bioaccumulation factors associated with soil and fern [As] to elucidate relationships between invertebrate and environmental As exposure. We collected invertebrates in pitfall traps from field sites associated with P. vittata, and identified them to order for whole body arsenic analysis and subsequently family for classification into functional feeding groups. We found that overall [As] in invertebrates increased with soil [As], but not with fern [As]. The absence of a relationship between fern [As] and invertebrate [As] may indicate invertebrates are avoiding the fern. Individual taxonomic groups significantly differed in whole body [As], and individual taxa also varied in their relationship between whole body [As] relative to soil and fern [As]. Overall invertebrate abundance decreased as invertebrate [As] load increased but varied across taxa. One particular herbivore, Callopistria floridensis (Florida fern caterpillar), associated with relatively low environmental As exposure contained over 4,000 mg kg(-1) As. Our results show that As bioaccumulates into higher trophic levels and invertebrate body [As] covary with exposure to naturally occurring environmental [As] associated with P. vittata. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island Based on Chloroplast Genome Sequencing.

    Science.gov (United States)

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  4. Survival and growth of epiphytic ferns depend on resource sharing

    Directory of Open Access Journals (Sweden)

    Hua-Zheng eLu

    2016-03-01

    Full Text Available Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets and another on groups (several ramets within a plot, with severed and intact rhizome treatments (without and with physiological integration on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  5. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    Science.gov (United States)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  6. On the infinite fern of Galois representations of unitary type

    CERN Document Server

    Chenevier, Gaetan

    2009-01-01

    Let E be a CM number field, F its maximal totally real subfield, c the generator of Gal(E/F), p an odd prime totally split in E, and S a finite set of places of E containing the places above p. Let r : G_{E,S} --> GL_3(F_p^bar) be a modular, absolutely irreducible, Galois representation of type U(3), i.e. such that r^* = r^c, and let X(r) be the rigid analytic generic fiber of its universal G_{E,S}-deformation of type U(3). We show that each irreducible component of the Zariski-closure of the modular points in X(r) has dimension at least 6[F:Q]. We study an analogue of the infinite fern of Gouvea-Mazur in this context and deal with the Hilbert modular case as well. As important steps, we prove that any first order deformation of a generic enough crystalline representation of Gal(Q_p^bar/Q_p) (of any dimension) is a linear combination of trianguline deformations, and that unitary eigenvarieties (of any rank) are etale over the weight space at the non-critical classical points. As another application, we obtain...

  7. Essential Oil Constituents and Antioxidant Activity of Asplenium Ferns.

    Science.gov (United States)

    Hammami, Saoussen; Snène, Ali; El Mokni, Ridha; Faidi, Khaled; Falconieri, Danilo; Dhaouadi, Hatem; Piras, Alessandra; Mighri, Zine; Porcedda, Silvia

    2016-09-01

    Two fern species Asplenium adiantum-nigrum L. and Asplenium trichomanes L. collected from the Kroumiria region (Northwest of Tunisia) were individually submitted to hydrodistillation in a Clevenger type apparatus. Volatile organic compounds were identified by GC-MS and GC-FID. Thus, 35 compounds were identified in A. adiantum-nigrum essential oil accounting for 77.5% of the whole constituents dominated by palmitic acid (34.5%); however, only 29 volatiles were identified in A. trichomanes showing a high amount of phytol, an odorous diterpene alcohol, representing 14.4% of the total oil contents. The total phenolic content and the antioxidant effects of crude extracts from both pteridophytes were determined using Folin-Ciocalteu and 2,2'-diphenyl-1-picrylhydrazyl free radical-scavenging assays, respectively. A. adiantum-nigrum ethyl acetate extract is shown to be lower in total phenolic contents (49.3 mg gallic acid equivalent/g) than similar extract from A. trichomanes (55.4 mg GAE/g).

  8. Survival and Growth of Epiphytic Ferns Depend on Resource Sharing.

    Science.gov (United States)

    Lu, Hua-Zheng; Song, Liang; Liu, Wen-Yao; Xu, Xing-Liang; Hu, Yue-Hua; Shi, Xian-Meng; Li, Su; Ma, Wen-Zhang; Chang, Yan-Fen; Fan, Ze-Xin; Lu, Shu-Gang; Wu, Yi; Yu, Fei-Hai

    2016-01-01

    Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing) on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets) and another on groups (several ramets within a plot), with severed and intact rhizome treatments (without and with physiological integration) on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium) in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration) significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  9. Effects of nickel on the fern Regnellidium diphyllum Lindm. (Marsileaceae

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    MA. Kieling-Rubio

    Full Text Available The heterosporous fern Regnellidium diphyllum occurs in southern Brazil and some adjoining localities in Uruguay and Argentina. Currently it is on the list of threatened species in the state of Rio Grande do Sul. Anthropic alterations such as the conversion of wetlands into agricultural areas or water and soil contamination by pollutants may compromise the establishment and survival of this species. Nickel (Ni is an essential nutrient for plants but increasing levels of this metal due to pollution can cause deleterious effects especially in aquatic macrophytes. Megaspore germination tests were performed using Meyer's solution, at concentrations of 0 (control, 0.05, 0.5, 1, 5, 10, 20, 30, 50 and 100 mg L-1 of Ni. The initial development of apomictic sporophytes was studied using solutions containing 0 (control to 4.8 mg L-1 of Ni. A significant negative relation was observed between the different Ni concentrations and the megaspore germination/sporophyte formation rates. Primary roots, primary leaves and secondary leaves were significantly shorter at 3.2 and 4.8 mg L-1 of Ni, when compared with the treatment without this metal. At 4.8 mg L-1, leaves also presented chlorosis and necrosis. The introduction of pollutants with Ni in the natural habitat of Regnellidium diphyllum may inhibit the establishment of plants in the initial stage of development, a problem to be considered in relation to the conservation of this species.

  10. Arsenic in the rhizosphere soil solution of ferns.

    Science.gov (United States)

    Wei, Chaoyang; Zheng, Huan; Yu, Jiangping

    2012-12-01

    The aim of this study was to explore the evidence of arsenic hyperaccumulation in plant rhizosphere solutions. Six common fern plants were selected and grown in three types of substrate: arsenic (As) -tailings, As-spiked soil, and soil-As-tailing composites. A rhizobox was designed with an in-situ collection of soil solutions to analyze changes in the As concentration and valence as well as the pH, dissolved organic carbon (DOC) and total nitrogen (TN). Arsenite composed less than 20% of the total As, and As depletion was consistent with N depletion in the rhizosphere solutions of the various treatments. The As concentrations in the rhizosphere and non-rhizosphere solutions in the presence of plants were lower than in the respective controls without plants, except for in the As-spiked soils. The DOC concentrations were invariably higher in the rhizosphere versus non-rhizosphere solutions from the various plants; however, no significant increase in the DOC content was observed in Pteris vittata, in which only a slight decrease in pH appeared in the rhizosphere compared to non-rhizosphere solutions. The results showed that As reduction by plant roots was limited, acidification-induced solubilization was not the mechanism for As hyperaccumulation.

  11. Fern-associated arbuscular mycorrhizal fungi are represented by multiple Glomus spp.: do environmental factors influence partner identity?

    Science.gov (United States)

    West, Brittany; Brandt, Jessica; Holstien, Kay; Hill, April; Hill, Malcolm

    2009-06-01

    Symbioses involving arbuscular mycorrhizal fungi (AMF) are among the most important ecological associations for many plant species. The diversity of AMF associated with ferns, however, remains poorly studied. Using recently designed Glomus-specific primers, we surveyed the AMF community associated with ferns from deciduous, broad-leaved second-growth forest habitats at the eastern edge of the piedmont region of central Virginia, USA. Results indicate that this molecular approach may be a useful tool for detecting AMF in ferns compared to traditional techniques based on morphology. Over 30 potential fungal ribotypes were identified from eight fern species using denaturing gradient gel electrophoresis. Fungal ribotypes were found to differ widely in terms of (1) the number of fern partners with which they interact and (2) their relative frequency within each fern. Sequence analysis of fungal isolates from three species of fern indicated that the primers were generally highly specific for Glomus species but some non-target DNA was also amplified. Cloned polymerase chain reaction (PCR) products from Polystichum acrostichoides and Osmunda regalis revealed several phylogenetically distinct Glomus species. A single Glomus species was identified in the cloned PCR products from Botrychium virginianum. These findings challenge the hypothesis that the extent or degree of fern-fungal symbiosis is somehow tied to root complexity. Environmental factors appear to influence the suite of AMF that form partnerships with ferns. Some species of fern from similar habitats associated with dissimilar fungal partners (e.g., P. acrostichoides and Athyrium filix-femina var. asplenioides), whereas others harbored uniform fungal communities (e.g., Asplenium platyneuron). The significance of these data in terms of ecological and evolutionary dynamics of the AMF-fern symbiosis is discussed.

  12. Restoring Native Forest Understory: The Influence of Ferns and Light in a Hawaiian Experiment

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    Robert Shallenberger

    2013-03-01

    Full Text Available Ecological restoration is an increasingly important component of sustainable land management. We explore potential facilitative relationships for enhancing the cost-effectiveness of restoring native forest understory, focusing on two factors: (1 overstory shade and (2 possible facilitation by a fern (Dryopteris wallichiana, one of few native colonists of pasture in our montane Hawaiˈi study system. We planted 720 understory tree seedlings and over 4000 seeds of six species under six planting treatments: a full factorial combination of low, medium and high light, situating plantings in either the presence or absence of a mature fern. After three years, 75% of outplanted seedlings survived. Seedling survivorship was significantly higher in the presence of a fern (79% vs. 71% without a fern and in medium and low light conditions (81% vs. 64% in high light. Relative height was highest at low to medium light levels. After 2.2 years, 2.8% of the planted seeds germinated. We observed no significant differences in seed germination relative to light level or fern presence. Analyzing several approaches, we found nursery germination of seeds followed by outplanting ca. 20% less costly than direct seeding in the field. This study opens new questions about facilitation mechanisms that have the potential to increase the extent and effectiveness of restoration efforts.

  13. Edge effects on fern community in an Atlantic Forest remnant of Rio Formoso, PE, Brazil.

    Science.gov (United States)

    Silva, I A A; Pereira, A F N; Barros, I C L

    2011-05-01

    We have investigated how edge effects influence the fern community of Jaguarão Forest (08º 35' 49" S and 35º 15' 39" W), located in the district of Rio Formoso, Pernambuco, Brazil. A comparative analysis was made of the interior and edge of the fragment of forest, regarding the richness, abundance and diversity of ferns in the two areas. Six plots of 10 × 20 m were chosen, three in each area. A total of 381 ferns were recorded, which were distributed among 25 species, 17 genera and 12 families. The two areas (edge and interior) were found to differ, with distinct relative air humidities and temperatures (p = 0.00254 and p = 0.00019, respectively). The interior showed higher diversity (t = 7.251 and p = 0.018) and richness (t = 6.379 and p = 0.023) than the edge area, but the same abundance (t = 1.728; p = 0.226) as the edge. Regarding the composition of the flora, it was clear that the interior is a habitat completely distinct from the edge with regard to the fern community, given that only one species, Adiantum petiolatum Desv., was common to both environments. It was concluded that the edge effect causes a decrease in richness and abundance of the fern species found in Jaguarão Forest, where the more sensitive species are being replaced by species that are tolerant to the disturbance caused by the creation of an edge.

  14. Ferns and lycopods--a potential treasury of anticancer agents but also a carcinogenic hazard.

    Science.gov (United States)

    Tomšík, Pavel

    2014-06-01

    Many species of seedless vascular plants-ferns and lycopods-have been used as food and folk medicine since ancient times. Some of them have become the focus of intensive research concerning their anticancer properties. Studies on the anticancer effect of crude extracts are being increasingly replaced by bioactivity-guided fractionation, as well as detailed assessment of the mechanism of action. Numerous compounds-especially flavonoids such as amentoflavone and protoapigenone, and also simpler phenolic compounds, steroids, alkaloids and terpenoids-were isolated and found to be cytotoxic, particularly pro-apoptotic, or to induce cell cycle arrest in cancer cell lines in vitro. In in vivo experiments, some fern-derived compounds inhibited tumour growth with little toxicity. On the other hand, many ferns-not only the well-known Bracken (Pteridium)-may pose a significant hazard to human health due to the fact that they contain carcinogenic sesquiterpenoids and their analogues. The objective of this review is to summarise the recent state of research on the anticancer properties of ferns and lycopods, with a focus on their characteristic bioactive constituents. The carcinogenic hazard posed by ferns is also mentioned.

  15. Knowledge-Based Estimation of Edible Fern Harvesting Sites in Mountainous Communities of Northeastern Japan

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    Toshiya Matsuura

    2013-12-01

    Full Text Available Once local expert knowledge regarding the harvesting of various non-timber forest products (NTFPs is lost, it is difficult to recover. We investigated whether the knowledge of expert forest harvesters can be used to determine the habitat distribution and harvesting sites of three popular edible wild ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous communities of western Fukushima, Japan. Using multi-criteria evaluation (MCE based on the analytic hierarchy process (AHP and geographic information system (GIS, we found that harvesters were easily able to recognize differences in the spatial characteristics of the habitat distribution of fern species due to both natural and anthropogenic factors. These factors were described by various GIS layers, such as vegetation and terrain features (e.g., gradient, aspect, and slope position derived from a 20-m digital elevation model (DEM. Harvesting sites were limited by their distance from a roadway, which differed among species. By comparison with the GPS records of actual harvesting sites, we estimated the potential harvesting sites of each fern species with reasonable accuracy, particularly for bracken. Our results show that the knowledge of expert forest harvesters can be quantified using MCE and GIS, which is useful for determining the spatial characteristics of NTFP harvesting and ensuring sustainable management practices.

  16. Soral Crypsis: Protective Mimicry of a Coccid on an Indian Fern

    Institute of Scientific and Technical Information of China (English)

    Biplab Patra; Subir Bera; R. James Hickey

    2008-01-01

    Herbivory with crypsis is not well documented in ferns. The present record of cryptic coloration of coccid Saissetia filicum Boisduval (Homoptera: Coccidae) to the sori of a fern species Asplenium nidus L. (Aspleniaceae) is unique. Predatory beetles (Jauravia sp., Coleoptera: Coccinellidae) that feed on the coccids, are suggested to be selective pressure for the development of the present homopteran soral crypsis. A higher rate of effective predation is noticed in the vegetative leaves than the fertile leaves. Aggressive ants were found harvesting honeydew secretions from the coccids and defending the trophobionts as well as the host fern from their natural enemies. In addition, a possible three-way mutualistic relationship among the coccids, its host fern and the tending ant is suggested. Differential numbers of coccids on vegetative and fertile leaves is correlated with their phenol content and degree of predation by beetles. Such coloration mimicry by the coccids may enable them to obtain the necessary blend of sorus of the host fern needed to evade beetle detection and attack.

  17. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted so

  18. Plastome sequences of Lygodium japonicum and Marsilea crenata reveal the genome organization transformation from basal ferns to core leptosporangiates.

    Science.gov (United States)

    Gao, Lei; Wang, Bo; Wang, Zhi-Wei; Zhou, Yuan; Su, Ying-Juan; Wang, Ting

    2013-01-01

    Previous studies have shown that core leptosporangiates, the most species-rich group of extant ferns (monilophytes), have a distinct plastid genome (plastome) organization pattern from basal fern lineages. However, the details of genome structure transformation from ancestral ferns to core leptosporangiates remain unclear because of limited plastome data available. Here, we have determined the complete chloroplast genome sequences of Lygodium japonicum (Lygodiaceae), a member of schizaeoid ferns (Schizaeales), and Marsilea crenata (Marsileaceae), a representative of heterosporous ferns (Salviniales). The two species represent the sister and the basal lineages of core leptosporangiates, respectively, for which the plastome sequences are currently unavailable. Comparative genomic analysis of all sequenced fern plastomes reveals that the gene order of L. japonicum plastome occupies an intermediate position between that of basal ferns and core leptosporangiates. The two exons of the fern ndhB gene have a unique pattern of intragenic copy number variances. Specifically, the substitution rate heterogeneity between the two exons is congruent with their copy number changes, confirming the constraint role that inverted repeats may play on the substitution rate of chloroplast gene sequences.

  19. 76 FR 45649 - Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange Project: Jackson County, OR

    Science.gov (United States)

    2011-07-29

    ... Federal Highway Administration Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange... the meaning of 23 U.S.C. 139(l)(1). The actions relate to a proposed highway project, I-5: Fern Valley... Administration, 530 Center Street, NE., Suite 420, Salem, Oregon 97301, Telephone: (503) 316-2559. The I-5:...

  20. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted

  1. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective

    NARCIS (Netherlands)

    Groot, de G.A.; During, H.J.; Maas, J.W.; Schneider, H.; Erkens, R.H.J.

    2011-01-01

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes—while playing an esse

  2. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.;

    2011-01-01

    adapted cheilanthoid ferns. To test this hypothesis with special emphasis on the alternative hypothesis of frequent colonization, the phylogenetic relations, divergence times, and ancestral areas of the cheilanthoid ferns of the GCFR and adjacent regions are investigated. The dataset includes 22...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe...... of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  3. Volatile organic compounds in the strongly fragrant fern genus Melpomene (Polypodiaceae).

    Science.gov (United States)

    Kessler, M; Connor, E; Lehnert, M

    2015-03-01

    Volatile organic compounds (VOCs) are common among plants, both as attractants for pollinators and as defence against herbivores. While much studied among flowering plants, the prevalence and function of VOCs among ferns is little known. Using headspace sorption and gas chromatography, we analysed the VOCs of dried specimens of six species of grammitid fern (Polypodiaceae), including two species of the genus Melpomene, which is characterised by a distinctive sweet smell. We identified 38 VOCs, including 22 not previously recorded among ferns. The two species of Melpomene had distinct VOC cocktails, including 12 substances not found in the other four studied genera, mainly involving fatty acid derivatives (FADs) and aromatics. We propose that these VOCs have, at least in part, a function in herbivore defence, but note that the VOC bouquet of Melpomene is distinct from that typically found in angiosperms.

  4. Identifying potential habitat for the endangered Aleutian shield fern using topographical characteristics

    Science.gov (United States)

    Duarte, Adam; Wolcott, Daniel M.; Chow, T. Edwin

    2012-01-01

    The Aleutian shield fern Polystichum aleuticum is endemic to the Aleutian archipelago of Alaska and is listed as endangered pursuant to the U.S. Endangered Species Act. Despite numerous efforts to discover new populations of this species, only four known populations are documented to date, and information is needed to prioritize locations for future surveys. Therefore, we incorporated topographical habitat characteristics (elevation, slope, aspect, distance from coastline, and anthropogenic footprint) found at known Aleutian shield fern locations into a Geographical Information System (GIS) model to create a habitat suitability map for the entirety of the Andreaonof Islands. A total of 18 islands contained 489.26 km2 of highly suitable and moderately suitable habitat when weighting each factor equally. This study reports a habitat suitability map for the endangered Aleutian shield fern using topographical characteristics, which can be used to assist current and future recovery efforts for the species.

  5. An Early Cretaceous root-climbing epiphyte (Lindsaeaceae) and its significance for calibrating the diversification of polypodiaceous ferns.

    Science.gov (United States)

    Schneider, H; Kenrick, P

    2001-05-01

    The discovery of fossilised roots of a lindsaeoid fern within the trunk of the extinct tree fern Tempskya provides new fossil evidence for Lindsaeaceae in the Mesozic, as well as the first direct evidence of an ecological association between Tempskya and root-climbing epiphytes. Data were collected from permineralised Tempskya trunks from the Aspen Shale (Early Cretaceous, Albian), Wyoming (USA). The roots of the lindsaeoid fossil are clearly distinguishable from those of Tempskya and other living ferns based on a suite of distinctive anatomical features, which are described in detail. The foliage is unknown. The new fossil is interpreted as a root climber, and comparisons are made with similar living species in Lindsaea subgenus Odontoloma (Lindsaeaceae). The documentation of Lindsaeaceae in the Early Cretaceous adds to a small but growing body of data on the diversification of polypodiaceous ferns during this important period. These recent discoveries point to a much earlier (Early Cretaceous) crown group radiation of polypodiaceous ferns than previously suspected.

  6. FERN – a Java framework for stochastic simulation and evaluation of reaction networks

    Directory of Open Access Journals (Sweden)

    Zimmer Ralf

    2008-08-01

    Full Text Available Abstract Background Stochastic simulation can be used to illustrate the development of biological systems over time and the stochastic nature of these processes. Currently available programs for stochastic simulation, however, are limited in that they either a do not provide the most efficient simulation algorithms and are difficult to extend, b cannot be easily integrated into other applications or c do not allow to monitor and intervene during the simulation process in an easy and intuitive way. Thus, in order to use stochastic simulation in innovative high-level modeling and analysis approaches more flexible tools are necessary. Results In this article, we present FERN (Framework for Evaluation of Reaction Networks, a Java framework for the efficient simulation of chemical reaction networks. FERN is subdivided into three layers for network representation, simulation and visualization of the simulation results each of which can be easily extended. It provides efficient and accurate state-of-the-art stochastic simulation algorithms for well-mixed chemical systems and a powerful observer system, which makes it possible to track and control the simulation progress on every level. To illustrate how FERN can be easily integrated into other systems biology applications, plugins to Cytoscape and CellDesigner are included. These plugins make it possible to run simulations and to observe the simulation progress in a reaction network in real-time from within the Cytoscape or CellDesigner environment. Conclusion FERN addresses shortcomings of currently available stochastic simulation programs in several ways. First, it provides a broad range of efficient and accurate algorithms both for exact and approximate stochastic simulation and a simple interface for extending to new algorithms. FERN's implementations are considerably faster than the C implementations of gillespie2 or the Java implementations of ISBJava. Second, it can be used in a straightforward

  7. Not only in the temperate zone: independent gametophytes of two vittarioid ferns (Pteridaceae, Polypodiales) in East Asian subtropics.

    Science.gov (United States)

    Kuo, Li-Yaung; Chen, Cheng-Wei; Shinohara, Wataru; Ebihara, Atsushi; Kudoh, Hiroshi; Sato, Hirotoshi; Huang, Yao-Moan; Chiou, Wen-Liang

    2017-03-01

    Independent gametophyte ferns are unique among vascular plants because they are sporophyteless and reproduce asexually to maintain their populations in the gametophyte generation. Such ferns had been primarily discovered in temperate zone, and usually hypothesized with (sub)tropical origins and subsequent extinction of sporophyte due to climate change during glaciations. Presumably, independent fern gametophytes are unlikely to be distributed in tropics and subtropics because of relatively stable climates which are less affected by glaciations. Nonetheless, the current study presents cases of two independent gametophyte fern species in subtropic East Asia. In this study, we applied plastid DNA sequences (trnL-L-F and matK + ndhF + chlL datasets) and comprehensive sampling (~80%) of congeneric species for molecular identification and divergence time estimation of these independent fern gametophytes. The two independent gametophyte ferns were found belonging to genus Haplopteris (vittarioids, Pteridaceae) and no genetic identical sporophyte species in East Asia. For one species, divergence times between its populations imply recent oversea dispersal(s) by spores occurred during Pleistocene. By examining their ex situ and in situ fertility, prezygotic sterility was found in these two Haplopteris, in which gametangia were not or very seldom observed, and this prezygotic sterility might attribute to their lacks of functional sporophytes. Our field observation and survey on their habitats suggest microhabitat conditions might attribute to this prezygotic sterility. These findings point to consideration of whether recent climate change during the Pleistocene glaciation resulted in ecophysiological maladaptation of non-temperate independent gametophyte ferns. In addition, we provided a new definition to classify fern gametophyte independences at the population level. We expect that continued investigations into tropical and subtropical fern gametophyte floras will

  8. Preliminary investigations on fossil diversity variation of Mesozoic Marattialean ferns in China

    Institute of Scientific and Technical Information of China (English)

    Zikun JIANG; Yongdong WANG; and Ning TIAN

    2008-01-01

    The Marattiales is one of the oldest lineages of vascular plants with extensive fossil records dated back to the Carboniferous. Understanding the fossil diversity variation and distribution pattern is helpful for exploring the evolutionary history of this fern group. In this work, the preliminary analysis of diversity change and distribution of the Mesozoic Marattialean fossil records in China are reported covering the Triassic and Jurassic periods based on available published data. In addition, a brief discussion is made regarding to the potential causes for these variation and distribution of this fern group.

  9. Determination of heavy metals in soil and different parts of Diplazium esculentum (medicinal fern)

    Science.gov (United States)

    Jasim, Hind S.; Idris, Mushrifah; Abdullah, Aminah; Kadhum, A. A. H.

    2014-09-01

    Diplazium esculentum is a widely used medicinal fern in Malaysia and other regions worldwide. Heavy metals in plants should be determined because prolonged human intake of toxic trace elements, even at low doses, results in organ malfunction and causes chronic toxicity. Hence, substantial information should be obtained from plants that grow on soils containing high concentrations of heavy metals. This study aimed to determine the physicochemical characteristics of soil and heavy metal concentrations (Pb, Cr, Mn, Cu, and Zn) in different parts of D. esculentum and soil, which were collected from the fern garden of Universiti Kebangsaan Malaysia. Results showed that heavy metals were highly accumulated in D. esculentum roots.

  10. CLINICAL APPLICATION AND EVALUATION OF SALIVA FERNING TEST IN SJGREN S SYNDROME

    Institute of Scientific and Technical Information of China (English)

    丁玲; 唐燕

    2000-01-01

    ffeStnn6 Objectif L' dtude admit pour but d' aPPrdcier to wileur du test de foug4rimtion (Ferning Test ) adns ie diagnostic de xdrostwnie chez ies malaies atteints du Syndrew de Sjbgren (ss). methaes ho dchantillons dewtnd de alivefraiche out did Obtenus chez 78 malades avec ie diagnostic de SS etabli scion ies critsres de ~munautd Eurowinne et chez 80tdmoins dins. ie dchantillons out ate ~mind sons microscope ordinaire. In cristallimtion etait classifide en 4 type scion iePhenondne de fougdrimtion (ferning...

  11. A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica.

    OpenAIRE

    Rojas Alvarado, Alexander Fco.; Palacios Ríos, Mónica

    2014-01-01

    Abstract: A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica. The new fern species Pteris herrerae A. Rojas & M. Palacios, endemic to Costa Rica, is described. It differs from P. decurrens C. Presl in basal segments reduced to 1/5-1/2 of the next segment (vs. 2/3-3/4), basal pinnae not bifurcated (vs. bifurcated), pinnae apex mucronate (vs. acuminate) and segment apex undulate (vs. dentate). It differs from Pteris consanguinea in the elliptic pinnae (vs. ...

  12. FURTHER NOTES ON THE FERN-GENUS HETEROGONIUM PRESL

    Directory of Open Access Journals (Sweden)

    R. E. HOLTTUM

    2015-11-01

    Full Text Available In the "Sarawak Museum Journal," volume V (1949, pages 156-166,I gave a revised account of the genus Heterogonium Presl, based on specimens in the Singapore herbarium. Dr M. A. Donk wrote subsequently pointing out that specimens at Bogor (Buitenzorg add materially to the information contained in that paper. The present paper gives the result of a study of the Bogor specimens. I am glad to express my gratitude to Dr Donk for calling my attention to species which I had overlooked when searching literature on Malaysian ferns for indications of affinity to Heterogonium. The Bogor material includes the type specimens of Acrostichum teysmannianum Bak., Phegopteris schizoloma v. A. v. R. Dryopteris sagenoides forma contracta v. A. v. R., Polybotrya nieuwenhuisii Racib. and Polybotrya nieuwenhuisii var. brooksii v. A. v. R., also many sheets of H. giganteum, and material of H. sagenoides from a wider geographic range than I had previously seen. Summarizing the results of the present paper, I have united H.nieuwenhuisii and H. stenosemioides of my former paper, and have also united H. saxicola with H. giganteum. Further, I now recognize a second exindusiate species allied to H. sagenoides; but the variation in pubescence among exindusiate specimens, as within the species H. sagenoides proper, is very considerable, and I find it very difficult to draw specific limits. It is likely that there are local races, but much more field work in many localities is necessary before one can speak with certainty about this or define their status taxonomically. One interesting fact is that no exindusiate specimens of this alliance have been found in the Malay Peninsula, whereas Peninsular collections of indusiate H. sagenoides aremore abundant than from any other area. It is especially the variation in pubescence among specimens of H. sagenoides, and the lack of clear-cut varieties or subspecies within the Malay Peninsula, that deters me from distinguishing more

  13. Diffusional limitations explain the lower photosynthetic capacity of ferns as compared with angiosperms in a common garden study.

    Science.gov (United States)

    Carriquí, M; Cabrera, H M; Conesa, M À; Coopman, R E; Douthe, C; Gago, J; Gallé, A; Galmés, J; Ribas-Carbo, M; Tomás, M; Flexas, J

    2015-03-01

    Ferns are thought to have lower photosynthetic rates than angiosperms and they lack fine stomatal regulation. However, no study has directly compared photosynthesis in plants of both groups grown under optimal conditions in a common environment. We present a common garden comparison of seven angiosperms and seven ferns paired by habitat preference, with the aims of (1) confirming that ferns do have lower photosynthesis capacity than angiosperms and quantifying these differences; (2) determining the importance of diffusional versus biochemical limitations; and (3) analysing the potential implication of leaf anatomical traits in setting the photosynthesis capacity in both groups. On average, the photosynthetic rate of ferns was about half that of angiosperms, and they exhibited lower stomatal and mesophyll conductance to CO2 (gm ), maximum velocity of carboxylation and electron transport rate. A quantitative limitation analysis revealed that stomatal and mesophyll conductances were co-responsible for the lower photosynthesis of ferns as compared with angiosperms. However, gm alone was the most constraining factor for photosynthesis in ferns. Consistently, leaf anatomy showed important differences between angiosperms and ferns, especially in cell wall thickness and the surface of chloroplasts exposed to intercellular air spaces.

  14. Effects of Flavonoids Extracted from Sweet Fern and Bitter Fern on DPPH Elimination%食用甜蕨及苦蕨黄酮类化合物对DPPH自由基的清除效果

    Institute of Scientific and Technical Information of China (English)

    方玉梅; 谭萍; 王毅红; 张春生

    2012-01-01

    为了弄清食用甜蕨和苦蕨黄酮提取物的抗氧化特性,以VE为对照,采用分光光度法等方法,研究了食用甜蕨和苦蕨黄酮类化合物对DPPH自由基清除率的影响.结果表明;在510nm下,甜蕨和苦蕨黄酮提取液的含量分别为843.59μg/g和614.15μg/g;甜蕨和苦蕨黄酮提取物对DPPH均有较好的清除效果,苦蕨与甜蕨黄酮提取物浓度为12.283μg/mL时,对DPPH的清除率分别为87,13%和50.21%,苦蕨黄酮提取液的抗氧化能力显著高于甜蕨,但二者的抗氧化能力均显著高于VE.%In order to ascertain the antioxidant properties of flavonoids extracted from sweet fern and bitter fern, the elimination rate on DPPH radical was studied taking VE as the control using spectrophotometric and other methods. The results showed that at 510 nm, the content of flavonoids extract of sweet fern and bitter fern was 843. 59 μg/g and 614. 15 μg/g respectively. The extraction of the flavonoids from sweet fern and bitter fern on DPPH elimination had The better effect. The flavonoids extracted from the sweet fern and bitter fern on DPPH elimination rate was 50. 21% and 87. 13% separately when the flavonoids concentration was 12. 283 μg/mL. The antioxidant capacity of the bitter fern flavonoids was significantly higher than that of the sweet fern flavonoids, but the antioxidant capacity of the sweet fern and bitter fern were significantly higher than VE.

  15. Seed ferns survived the end-Cretaceous mass extinction in Tasmania.

    Science.gov (United States)

    McLoughlin, Stephen; Carpenter, Raymond J; Jordan, Gregory J; Hill, Robert S

    2008-04-01

    Seed ferns, dominant elements of the vegetation in many parts of the world from the Triassic to Cretaceous, were considered to have disappeared at the end of the Cretaceous together with several other groups that had occupied key positions in terrestrial and marine ecosystems such as dinosaurs, plesiosaurs, and ammonoids. Seed-fern demise is generally correlated with competition from diversifying flowering plants through the Cretaceous and the global environmental crisis related to the Chicxulub impact event in the paleotropics at the end of the period. New fossils from Tasmania show that one seed-fern lineage survived into the Cenozoic by at least 13 million years. These fossils are described here as a new species, Komlopteris cenozoicus. Komlopteris is a genus of seed ferns attributed to Corystospermaceae and until now was not known from sediments younger than the Early Cretaceous. Discovery of this "Lazarus taxon," together with the presence of a range of other relictual fossil and extant organisms in Tasmania, other southern Gondwanan provinces, and some regions of northern North America and Asia, underscores high-latitude regions as biodiversity refugia during global environmental crises and highlights their importance as sources of postextinction radiations.

  16. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully de

  17. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  18. Cyathea nilgirensis Holttum (Cyatheaceae: Pteridophyta: a threatened tree fern from central Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.N. Dudani

    2014-01-01

    Full Text Available While studying some of the exclusive and threatened swamps overgrown with wild nutmeg trees (Myristica swamps, in the Kathalekan forest of Uttara Kannada in central Western Ghats, Cyathea nilgirensis Holttum, a southern Indian endemic tree fern was seen growing in the deep shade of the swampy forest. This is a new report of its distribution anywhere from north of Western Ghats.

  19. Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

    Science.gov (United States)

    Schuettpelz, Eric; Pryer, Kathleen M

    2006-06-01

    The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

  20. Rhizosphere and non-rhizosphere mycoflora of two ferns from Panhala Fort, Kolhapur, Maharashtra, India

    Directory of Open Access Journals (Sweden)

    P. R. Hande

    2016-03-01

    Full Text Available Hypodematium crenatum (Forssk. Kuhn and Anogramma leptophylla (L. Link are threatened fern species from Western Ghats.  The present paper endorses the preliminary study on mycoflora associated with these ferns.  Eighteen fungal species have been isolated from rhizosphere and non-rhizosphere soils of selected ferns.  More diversity of fungi was observed in non-rhizosphere as compared to rhizosphere soils of both the ferns.  Aspergillus was found to be the most dominant genus among the population followed by Penicillium.  Higher percentage of fungal species is shown by H. crenatum, i.e., 44.5% in non-rhizosphere and 27.77% in rhizosphere; while a lower percentage of fungal species was found in A. leptophylla, i.e., 38.88% in non-rhizosphere and 16.66% in rhizosphere.  Number of colony forming units per gram soil was more in non-rhizosphere of A. leptophylla while it was less in non-rhizosphere of H. crenatum.  Inhibitory rhizosphere effect was exerted by A. leptophylla while H. crenatum has stimulatory effect on soil fungi. 

  1. Qasimia gen. nov., an early Marattia-like fern from the Permian of Saudi Arabia

    NARCIS (Netherlands)

    Hill, C.R.; Wagner, R.H.; El-Khayal, A. A.

    1985-01-01

    The marattialean fern Qasimia schyfsmae (Lemoigne) gen. et comb. nov. is described from the Late Permian plant bed at Unayzah in central Saudi Arabia. Although no organic matter is preserved, impregnation of the compressions by iron minerals at an early stage of diagenesis has partly mineralised the

  2. Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns

    OpenAIRE

    Schmidt, AR; Heinrichs, J.; Schneider, Harald

    2016-01-01

    publisher: Elsevier articletitle: Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns journaltitle: Perspectives in Plant Ecology, Evolution and Systematics articlelink: http://dx.doi.org/10.1016/j.ppees.2016.01.003 content_type: article copyright: Copyright © 2016 Elsevier GmbH. All rights reserved.

  3. Notes on the scholarly trajectory of Mª. Dolores Fernández-Posse

    Directory of Open Access Journals (Sweden)

    Gilman, Antonio

    2007-12-01

    Full Text Available The scholarly trajectory of Mª Dolores Fernández- Posse involved an ongoing process of critical observation, reflection, and change that is quite rare in Archaeology. Her change from normativism to a historically informed functionalism is representative of the general evolution of Spanish archaeological studies over the course of the past thirty years. What is unusual about Fernández-Posse -and attests to her straightforward and unassuming intelligence- is that she herself changed her mind and voiced that change with clarity and humor.

    La trayectoria científica de Mª Dolores Fernández-Posse se caracterizó por un proceso continuo de observación crítica, reflexión y cambio, algo poco común en Arqueología. Su cambio del normativismo a un funcionalismo de orientación histórica es representativo de la evolución de los estudios arqueológicos en España a lo largo de los últimos treinta años. Lo realmente inusual de Fernández-Posse -y lo que atestigua su directa pero no pretenciosa inteligencia- es que ella misma cambió de ideas y publicitó ese cambio con claridad y humor.

  4. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  5. A Cognitive Reading Guide: Equalizing Instruction for "Where the Red Fern Grows."

    Science.gov (United States)

    Giannuzzi, Michelle L.; Hudson, Floyd

    1998-01-01

    Provides a cognitive reading guide for the first four chapters of the novel, "Where the Red Fern Grows" (Rawls, 1961), that incorporates teacher-directed whole-class instruction with a student reading guide to equalize instruction for various levels of learners. Ideas for whole-class instruction are contained within the lesson plans. (CR)

  6. Ever since Klekowski: testing a set of radical hypotheses revives the genetics of ferns and lycophytes.

    Science.gov (United States)

    Haufler, Christopher H

    2014-12-01

    There have been three periods of significant discovery in the exploration of fern and lycophyte genetics. First, during the 1930s, Andersson-Kottö conducted crossing studies on ferns. The publication of Manton's magnum opus on fern chromosomes in 1950 stimulated the second. The third emerged from Klekowski's 1973 American Journal of Botany publication that posed hypotheses linking breeding system dynamics and polyploid genetic architecture. Although Klekowski's assertions (predominant inbreeding and active polyploid genomes) were not supported, his hypotheses served as the impetus for improving our knowledge of the evolutionary mechanisms of ferns and lycophytes. It is now understood that (1) homosporous vascular plants are genetically diploid at high chromosome numbers and (2) both heterosporous and homosporous plants store and release genetic variation through a similar range of breeding systems. However, the seeming paradox of diploid genetic expression in homosporous vascular plants with high chromosome numbers remains unresolved. Ongoing and future research should include (1) more studies of gametophyte biology to elucidate the range and frequency of different breeding systems; (2) genomic analyses and new research on the mechanisms controlling bivalent formation to help discover how and why homosporous plant chromosomes appear so structurally stable; (3) considering whether the frequency of allopolyploidy in lineages can help explain why some are highly polyploid; and (4) chromosome painting studies to identify the dynamics of chromosome behavior in homosporous vascular plants. These open questions and continuing investigations demonstrate the longstanding impact of Klekowski's stimulating contribution.

  7. Alsophila weidenbrueckii (Cyatheaceae), a new scaly tree fern from Papua New Guinea

    NARCIS (Netherlands)

    Lehnert, M.

    2016-01-01

    The scaly tree fern Alsophila weidenbrueckii is described and illustrated as new to science. It occurs in the Bismarck range in north-eastern New Guinea at 1200–2100 m in evergreen wet mountain forest. The species reaches maturity at a comparatively old age and large size and regenerates only in int

  8. Interannual variation and host affiliations of endophytic fungi associated with ferns at La Selva, Costa Rica.

    Science.gov (United States)

    Del Olmo-Ruiz, Mariana; Arnold, A Elizabeth

    2014-01-01

    Ferns are an ancient and diverse lineage of vascular plants that differ morphologically, chemically and in growth habits from the angiosperms with which they co-occur. We used a culture-based approach coupled with phylogenetic analyses to characterize the incidence, diversity and composition of fungal endophyte assemblages in ferns, with a focus on healthy aboveground tissues of seven species of eupolypods at La Selva, Costa Rica. Endophytes were isolated from every individual plant and were similarly abundant and diverse in frond blades and stalks, in different vegetation types, in epiphytic vs. terrestrial species, and between sampling years. However, abundance, diversity and community structure differed significantly among fern species, and composition differed markedly between sampling years. Phylogenetic classification using separate and combined datasets revealed that as for many Neotropical angiosperms, the majority (95%) of endophyte taxa were Ascomycota, with particular dominance by Sordariomycetes, Eurotiomycetes and Dothideomycetes. However, our data suggest higher phylogenetic richness and stronger host affinities in fern associated endophytes relative to those studied in angiosperms thus far.

  9. Effect of temperature on green spore longevity for the ferns Equisetum ramosissimum and Osmunda regalis

    Science.gov (United States)

    Some fern species produce chlorophyllic or green spores. Green spores lose viability quickly compared to nongreen spores, and so need specialized treatment for long term conservation in germplasm banks. Dry storage at different temperatures (25 ºC, 4 ºC, -25 ºC, -80 ºC and -196 ºC) was studied in ...

  10. Effects of arsenic on nitrogen metabolism in arsenic hyperaccumulator and non-hyperaccumulator ferns

    Science.gov (United States)

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of two four-month old fern plants, Pteris vittata, an arsenic-hyperaccumulator, and Pteris ensiformis, ...

  11. Report of work on ferns carried out at Bogor 1957-1958

    NARCIS (Netherlands)

    Holttum, R.E.

    1959-01-01

    I spent the period from Oct. 8, 1957, to March 27, 1958, at Bogor, Indonesia. During that period I worked regularly in the Herbarium Bogoriense. The main part of my work consisted of a complete rearrangement of the fern herbarium, which consists of some 20,000- 30,000 specimens.

  12. Real-Time RGB-D Camera Relocalization via Randomized Ferns for Keyframe Encoding.

    Science.gov (United States)

    Glocker, Ben; Shotton, Jamie; Criminisi, Antonio; Izadi, Shahram

    2015-05-01

    Recovery from tracking failure is essential in any simultaneous localization and tracking system. In this context, we explore an efficient keyframe-based relocalization method based on frame encoding using randomized ferns. The method enables automatic discovery of keyframes through online harvesting in tracking mode, and fast retrieval of pose candidates in the case when tracking is lost. Frame encoding is achieved by applying simple binary feature tests which are stored in the nodes of an ensemble of randomized ferns. The concatenation of small block codes generated by each fern yields a global compact representation of camera frames. Based on those representations we define the frame dissimilarity as the block-wise hamming distance (BlockHD). Dissimilarities between an incoming query frame and a large set of keyframes can be efficiently evaluated by simply traversing the nodes of the ferns and counting image co-occurrences in corresponding code tables. In tracking mode, those dissimilarities decide whether a frame/pose pair is considered as a novel keyframe. For tracking recovery, poses of the most similar keyframes are retrieved and used for reinitialization of the tracking algorithm. The integration of our relocalization method into a hand-held KinectFusion system allows seamless continuation of mapping even when tracking is frequently lost.

  13. Coeval Eocene blooms of the freshwater fern Azolla in and around Arctic and Nordic seas

    NARCIS (Netherlands)

    Barke, J.; Burgh, A.H.P. van der; Konijnenburg-van Cittert, J.H.A. van; Collinson, M.E.; Pearce, M.A.; Bujak, J.; Heilman-Clausen, C.; Lotter, A.F.; Speelman, E.N.; Kempen, M.M.L. van; Reichart, G.-J.; Brinkhuis, H.

    2012-01-01

    For a short time interval (c. 1.2 Myr) during the early middle Eocene (~ 49 Myr), the central Arctic Ocean was episodically densely covered by the freshwater fern Azolla, implying sustained freshening of surface waters. Coeval Azolla fossils in neighboring Nordic seas were thought to have been

  14. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the

  15. Phytochemical studies on five medicinal ferns collected from Southern Western Ghats, Tamilnadu

    Institute of Scientific and Technical Information of China (English)

    A John De Britto; D Herin Sheeba Gracelin; P Benjamin Jeya Rathna Kumar

    2012-01-01

    Objective: To analyze the phytochemical constituents of five medicinal ferns Pteris biaurita (P. biaurita) L., Lygodium flexiuosam (L. flexiuosam) (L.) Sw., Hemionitis arifolia (H. arifolia) (Burm. f.) T. Moore, Actinopteris radiate (A. radiata) (J. Koenig ex Sw.) Link and Adiantum latifolium (A. latifolium) Lam. Methods: The shade dried and powdered fronds (50 g) were extracted successively with 250 mL of petroleum ether, benzene, chloroform, methanol and distilled water using a Soxhlet extractor for 8 h at a temperature of 50-60℃ (not exceeding the boiling point of the solvent). Phytochemical analysis of the extracts was carried out according to the standard procedures. Results: Among the twenty five tested extracts, twenty extracts showed the presence of flavonoids. Phenolic compounds are present in methanol extracts of all the ferns. Five extracts showed the presence of triterpinoids and catechins. Ten extracts showed the occurrence of sugars and reducing sugars. Fifteen extracts showed the presence of alkaloids. Tannins and saponins are present in eight extracts. Steroids occurred in all the twenty five extracts. Only three extracts showed the presence of anthroquinones and amino acids. Conclusions: From this investigation, it can be concluded that the selected five medicinal ferns contain more bioactive principles. These potential ferns could be used as bio control agnets.

  16. Community structure of ferns in riparian forest: evaluation in anthropization gradient

    Directory of Open Access Journals (Sweden)

    Ivanete Teresinha Mallmann

    2016-03-01

    Full Text Available Riparian forests are essential to the maintenance of biodiversity and foster the development of ferns that are indicators of environmental quality. However, these forests have been degraded due mainly to high population density, pattern of urban settlement and agricultural expansion in rural areas. This study evaluated the environmental quality of riparian vegetation of the Cadeia River in Southern Brazil, using phytosociological parameters of the understory’s fern community and a Rapid Assessment Protocol of Habitat Quality (RAPQH. One hundred and twenty plots of 25 m2 were equally distributed among three fragments (FI, FII, FIII. All species of herbaceous ferns were inventoried in each sample unit. We calculated parameters of density, frequency, relative dominance and importance value (IV of species for the analysis of community structure. The lowest species richness was recorded at FIII (seven species. The floristic composition is more heterogeneous and richness is higher in FI, where the parcels had greater plant cover and RAPQH scores. The RAPQH score decreased with increasing degree of urbanization in the surrounding matrix and FI and FII were classified as “natural,” while FIII was classified as “impacted.” Considering the four species with the highest IV in the three fragments (totaling 69.11% of IV in the FI, 78.36% and 91.06% in FII and FIII respectively, it can be affirmed that the fern community structure is degraded with increasing anthropization.

  17. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully

  18. SEM Studies on Vessels in Ferns. XV. Selected Rosette Epiphytes (Aspleniaceae, Elaphoglossaceae, Vittariaceae).

    Science.gov (United States)

    Schneider; Carlquist

    1999-09-01

    Tracheary elements from macerations of roots and rhizomes of Asplenium nidus, Elaphoglossum hirtum, and Vittaria lineata were studied by means of SEM. All of these have perforation plates in tracheary elements of both roots and rhizomes. The perforation plates in roots and rhizomes show greatest development of perforations (perforations a little wider than pits of tracheary elements) in E. hirtum roots and rhizomes and least in V. lineata roots and in rhizomes of A. nidus (porose pit membranes in many perforations). The secondary wall framework of perforation plates is little different from that of pitted wall areas in these three species. These rosette epiphytes have a lower degree of specialization of perforation plates that might accommodate rapid flow related to moisture availability fluctuations in comparison to perforation plates in vessels of rhizomatous epiphytic ferns. Generalizations are not warranted at this point, however. Rows of cushion-like structures occur adjacent to angles of the tracheary elements of E. hirtum. This is the first report of these in leptosporangiate ferns; they are known thus far only in a eusporangiate fern, Danaea elliptica (Marattiaceae). Raised frames of wall material around perforations are newly reported for tracheary elements of ferns in E. hirtum.

  19. rbcL and matK earn two thumbs up as the core DNA barcode for ferns.

    Directory of Open Access Journals (Sweden)

    Fay-Wei Li

    Full Text Available BACKGROUND: DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history--an endeavor previously impossible--will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK, as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F, across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade--Deparia (Woodsiaceae and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae--to further evaluate the resolving power of these loci. PRINCIPAL FINDINGS: Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. CONCLUSIONS: Our study provides the first endorsement of the two-locus barcode (rbcL+matK in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development.

  20. Exploring the utility of three nuclear regions to reconstruct reticulate evolution in the fern genus Asplenium

    Institute of Scientific and Technical Information of China (English)

    Harald SCHNEIDER; Adriana NAVARRO-GOMEZ; Stephen J.RUSSELL; Stephen ANSELL; Michal GRUNDMANN; Johannes VOGEL

    2013-01-01

    Three nuclear regions nuclear ribosomal internal transcribed spacer (nrITS) and intron regions of two nuclear low-copy genes-gapCp,and pgiC,in combination with one chloroplast genome region were employed to explore patterns of reticulate evolution in the fern genus Asplenium.This is the one of the first studies using DNA sequences of multiple nuclear markers in ferns.All three nuclear markers amplified well with PCR and several copies were recovered by cloning PCR products.All three nuclear regions showed congruent results by recovering the neo-allotetraploid Asplenium adulterinum as the hybrid of diploid A.trichomanes and diploid A.viride.Conflicting results were obtained for several nodes.First,gapCp did not discriminate between A.aethiopicum and A.praegracile whereas the other markers recovered these two taxa as distinct.Conflicts among gene-trees were found in respect to A.monanthes,chloroplast and pgiC suggested a sister relationship ofA.monanthes and A.trichomanes but gapCp and nrITS nested A.monanthes within A.normale.Our results confirm:(i) the usefulness of several nuclear regions,in particular gapCp and pgiC,to unravel reticulate evolution in ferns and species differentiation and (ii) highlights the need to employ more than one nuclear region to obtain reliable hypotheses on reticulate events versus incomplete lineage sorting.Especially,if one assumes that the reticulation event might have occurred in the more distant past.Considering the expected high frequency of reticulate evolution in ferns,the establishment of robust and informative nuclear genomic markers is critical to achieve further progress in our efforts to elucidate fern evolution.

  1. Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy.

    Science.gov (United States)

    Schuettpelz, Eric; Pryer, Kathleen M

    2009-07-07

    In today's angiosperm-dominated terrestrial ecosystems, leptosporangiate ferns are truly exceptional--accounting for 80% of the approximately 11,000 nonflowering vascular plant species. Recent studies have shown that this remarkable diversity is mostly the result of a major leptosporangiate radiation beginning in the Cretaceous, following the rise of angiosperms. This pattern is suggestive of an ecological opportunistic response, with the proliferation of flowering plants across the landscape resulting in the formation of many new niches--both on forest floors and within forest canopies--into which leptosporangiate ferns could diversify. At present, one-third of leptosporangiate species grow as epiphytes in the canopies of angiosperm-dominated tropical rain forests. However, we know too little about the evolutionary history of epiphytic ferns to assess whether or not their diversification was in fact linked to the establishment of these forests, as would be predicted by the ecological opportunistic response hypothesis. Here we provide new insight into leptosporangiate diversification and the evolution of epiphytism by integrating a 400-taxon molecular dataset with an expanded set of fossil age constraints. We find evidence for a burst of fern diversification in the Cenozoic, apparently driven by the evolution of epiphytism. Whether this explosive radiation was triggered simply by the establishment of modern angiosperm-dominated tropical rain forest canopies, or spurred on by some other large-scale extrinsic factor (e.g., climate change) remains to be determined. In either case, it is clear that in both the Cretaceous and Cenozoic, leptosporangiate ferns were adept at exploiting newly created niches in angiosperm-dominated ecosystems.

  2. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  3. The fern-spore abundance anomaly at the Cretaceous-Tertiary boundary: A regional bioevent in western North America

    Science.gov (United States)

    Fleming, R. F.; Nichols, D. J.

    At most localities where the palynological Cretaceous-Tertiary (K-T) boundary has been located in continuous deposition sequences in nonmarine rocks, an anomalous abundance of fern spores occurs immediately above the boundary. The fern-spore anomaly is characterized by unusually high relative abundance of fern spores and dominance by only one of a few species at each locality; it is independent of lithology. Its presence at the K-T boundary at localities from New Mexico to Saskatchewan is evidence of a regional bioevent in earliest Tertiary time: the overwhelming dominance of the continental flora by pioneer species following catastrophic destruction of existing plant communities by the terminal Cretaceous event.

  4. Different leaf cost-benefit strategies of ferns distributed in contrasting light habitats of sub-tropical forests

    National Research Council Canada - National Science Library

    Zhu, Shi-Dan; Li, Rong-Hua; Song, Juan; He, Peng-Cheng; Liu, Hui; Berninger, Frank; Ye, Qing

    2016-01-01

    ...) have a different leaf cost-benefit strategy compared with ferns that occur in natural forests (FNF), with a quicker return on carbon investment in disturbed habitats compared with old-growth forests...

  5. Ferns are less dependent on passive dilution by cell expansion to coordinate leaf vein and stomatal spacing than angiosperms.

    Science.gov (United States)

    Carins Murphy, Madeline R; Jordan, Gregory J; Brodribb, Timothy J

    2017-01-01

    Producing leaves with closely spaced veins is a key innovation linked to high rates of photosynthesis in angiosperms. A close geometric link between veins and stomata in angiosperms ensures that investment in enhanced venous water transport provides the strongest net carbon return to the plant. This link is underpinned by "passive dilution" via expansion of surrounding cells. However, it is not known whether this 'passive dilution' mechanism is present in plant lineages other than angiosperms and is another key feature of the angiosperms' evolutionary success. Consequently, we sought to determine whether the 'passive dilution' mechanism is; (i) exclusive to the angiosperms, (ii) a conserved mechanism that evolved in the common ancestor of ferns and angiosperms, or (iii) has evolved continuously over time. To do this we first we assessed the plasticity of vein and stomatal density and epidermal cell size in ferns in response to light environment. We then compared the relationships between these traits found among ferns with modelled relationships that assume vein and stomatal density respond passively to epidermal cell expansion, and with those previously observed in angiosperms. Vein density, stomatal density and epidermal cell size were linked in ferns with remarkably similar relationships to those observed in angiosperms, except that fern leaves had fewer veins per stomata. However, plasticity was limited in ferns and stomatal spacing was dependent on active stomatal differentiation as well as passive cell expansion. Thus, ferns (like angiosperms) appear to coordinate vein and stomatal density with epidermal cell expansion to some extent to maintain a constant ratio between veins and stomata in the leaf. The different general relationships between vein density and stomatal density in ferns and angiosperms suggests the groups have different optimum balances between the production of vein tissue dedicated to water supply and stomatal tissue for gas exchange.

  6. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica

    OpenAIRE

    Sosa, Victoria; Ornelas, Juan Francisco; Ramírez-Barahona, Santiago; Gándara, Etelvina

    2016-01-01

    Background Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted...

  7. Glycoside Hydrolase (GH) 45 and 5 Candidate Cellulases in Aphelenchoides besseyi Isolated from Bird’s-Nest Fern

    Science.gov (United States)

    Tsay, Tung-Tsuan; Tsai, Isheng J.; Chen, Peichen J.

    2016-01-01

    Five Aphelenchoides besseyi isolates collected from bird’s-nest ferns or rice possess different parasitic capacities in bird’s-nest fern. Two different glycoside hydrolase (GH) 45 genes were identified in the fern isolates, and only one was found in the rice isolates. A Abe GH5-1 gene containing an SCP-like family domain was found only in the fern isolates. Abe GH5-1 gene has five introns suggesting a eukaryotic origin. A maximum likelihood phylogeny revealed that Abe GH5-1 is part of the nematode monophyletic group that can be clearly distinguished from those of other eukaryotic and bacterial GH5 sequences with high bootstrap support values. The fern A. besseyi isolates were the first parasitic plant nematode found to possess both GH5 and GH45 genes. Surveying the genome of the five A. besseyi isolates by Southern blotting using an 834 bp probe targeting the GH5 domain suggests the presence of at least two copies in the fern-origin isolates but none in the rice-origin isolates. The in situ hybridization shows that the Abe GH5-1 gene is expressed in the nematode ovary and testis. Our study provides insights into the diversity of GH in isolates of plant parasitic nematodes of different host origins. PMID:27391812

  8. No evidence of general CO2 insensitivity in ferns: one stomatal control mechanism for all land plants?

    Science.gov (United States)

    Franks, Peter J; Britton-Harper, Zoe J

    2016-08-01

    Stomatal regulation of plant carbon uptake and water loss under changing environmental conditions was a crucial evolutionary step in the colonization of land by plants. There are currently two conflicting models describing the nature of stomatal regulation across terrestrial vascular plants: the first is characterized by a fundamental mechanistic similarity across all lineages, and the second is characterized by the evolution of major differences in angiosperms compared with more ancient lineages. Specifically, the second model posits that stomata of ferns lack a response to elevated atmospheric CO2 concentration (ca ) and therefore cannot regulate leaf intercellular CO2 concentration (ci ). We compared stomatal sensitivity to changes in ca in three distantly related fern species and a representative angiosperm species. Fern and angiosperm stomata responded strongly and similarly to changes in ca . As a result, ci /ca was maintained within narrow limits during ca changes. Our results challenge the model in which stomata of ferns generally lack a response to elevated ca and that angiosperms evolved new dynamic mechanisms for regulating leaf gas exchange that differ fundamentally from ferns. Instead, the results are consistent with a universal stomatal control mechanism that is fundamentally conserved across ferns and angiosperms, and therefore likely all vascular plant divisions.

  9. Invariant Hough random ferns for RGB-D-based object detection

    Science.gov (United States)

    Lou, Xiaoping; Dong, Mingli; Wang, Jun; Sun, Peng; Lin, Yimin

    2016-09-01

    This paper studies the challenging problem of object detection using rich image and depth features. An invariant Hough random ferns framework for RGB-D images is proposed here, which primarily consists of a rotation-invariant RGB-D local binary feature, random ferns classifier training, Hough mapping and voting, searches for the maxima, and back projection. In comparison with traditional three-dimensional local feature extraction techniques, this method is effective in reducing the amount of computation required for feature extraction and matching. Moreover, the detection results showed that the proposed method is robust against rotation and scale variations, changes in illumination, and part-occlusions. The authors believe that this method will facilitate the use of perception in fields such as robotics.

  10. Antheridiogen determines sex in ferns via a spatiotemporally split gibberellin synthesis pathway.

    Science.gov (United States)

    Tanaka, Junmu; Yano, Kenji; Aya, Koichiro; Hirano, Ko; Takehara, Sayaka; Koketsu, Eriko; Ordonio, Reynante Lacsamana; Park, Seung-Hyun; Nakajima, Masatoshi; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto

    2014-10-24

    Some ferns possess the ability to control their sex ratio to maintain genetic variation in their colony with the aid of antheridiogen pheromones, antheridium (male organ)-inducing compounds that are related to gibberellin. We determined that ferns have evolved an antheridiogen-mediated communication system to produce males by modifying the gibberellin biosynthetic pathway, which is split between two individuals of different developmental stages in the colony. Antheridiogen acts as a bridge between them because it is more readily taken up by prothalli than bioactive gibberellin. The pathway initiates in early-maturing prothalli (gametophytes) within a colony, which produce antheridiogens and secrete them into the environment. After the secreted antheridiogen is absorbed by neighboring late-maturing prothalli, it is modified in to bioactive gibberellin to trigger male organ formation.

  11. Solubility and accumulation of metals in Chinese brake fern, vetiver and rostrate sesbania using chelating agents.

    Science.gov (United States)

    Lou, L Q; Ye, Z H; Wong, M H

    2007-01-01

    Greenhouse experiments were conducted to study the effects of chelating agents on the growth and metal accumulation of Chinese brake fern (Pteris vittata L.), vetiver (Vetiveria zizanioides L.), and rostrate sesbania (Sesbania rostrata L.) in soil contaminated with arsenic (As), Cu, Pb, and Zn. Among the five chelating agents used [ethylenediaminetriacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), oxalic acid (OA), and phytic acid (PA)], OA was the best to mobilize As, EDTA to mobilize Cu and Pb, and HEDTA to mobilize Zn from soil, respectively. The biomass of vetiver was the highest, followed by rostrate sesbania. All chelating agents inhibited the growth of Chinese brake fern and rostrate sesbania, but HEDTA significantly increased the aboveground biomass of vetiver. Dry weights of both Chinese brake fern and rostrate sesbania decreased with increasing EDTA concentrations amended in the soil, especially in treatments with high EDTA concentrations. EDTA and HEDTA enhanced Cu, Zn, and Pb, but lowered As accumulation in all three plant species, except for As in vetiver, while OA significantly enhanced As accumulation in the aboveground part of vetiver. Concentrations of Cu, Zn, and Pb in the aboveground parts of plants increased significantly with the increase of EDTA concentrations and treatment time. In addition to As, Chinese brake fern also accumulated the highest Cu, Pb, and Zn in its aboveground parts among the three plant species grown in metal-contaminated soil with EDTA/HEDTA treatments. This species, therefore, can be used to simultaneously clean up As, Cu, Pb, and Zn from contaminated soils with the aid of EDTA or HEDTA.

  12. RESEARCHES CONCERNING THE IN VITRO DIFFERENTIATION OF THE FERN PHEGOPTERIS CONNECTILIS (MICHX.) WATT

    OpenAIRE

    Liliana Cristina SOARE; Emilia VISOIU; ANDREI, M.

    2007-01-01

    Phegopteris connectilis is an apogamous species, endangered in certain regions. The ex situ conservation, through the in vitro production of the gametophyte, as well as the embryos and the plants, followed by their cryo-stocking, is necessary for ensuring the survival of the endangered species, while at pace with international methodology. The differentiation of the gametophyte is characteristic of the leptosporangiate ferns, passing through the following stages: prothallic filament, prothall...

  13. First megafossil evidence of Cyatheaceous tree fern from the Indian Cenozoic

    Indian Academy of Sciences (India)

    Subir Bera; Sudha Gupta; Mahasin Ali Khan; Aniruddha De; Radhanath Mukhopadhyay

    2014-08-01

    A part of the compressed tree fern axis with leaf and adventitious root scars in unusual arrangement from Plio–Pleistocene sediments of Arunachal Pradesh, India is described as Cyathea siwalika sp. nov. This record suggests that Cyathea was an important component of tropical evergreen forest in the area during the Plio–Pleistocene and this group subsequently declined in importance within the local vegetation.

  14. DPPH FREE RADICAL SCAVENGER ACTIVITY OF FLAVONOID FROM THE LEAVES OF FERN Chingia sakayensis (Zeiller Holtt

    Directory of Open Access Journals (Sweden)

    Suyatno Suyatno

    2010-06-01

    Full Text Available A flavonoid compound in flavonol type namely kaemferol was isolated from the ethyl acetate fraction of the methanol extract of the fern Chingia sakayensis (Zeiller Holtt's leaves. The DPPH free radical scavenger activity of kaemferol was stronger than buthyl hyroxy toluene (BHT but it was weaker than ascorbic acid (vitamin C and -tocopherol (vitamin E.   Keywords: Chingia sakayensis, kaemferol, DPPH free radical scavenger activity

  15. Desiccation tolerance mechanism in resurrection fern-ally Selaginella tamariscina revealed by physiological and proteomic analysis.

    Science.gov (United States)

    Wang, Xiaonan; Chen, Sixue; Zhang, Heng; Shi, Lei; Cao, Fenglin; Guo, Lihai; Xie, Yongming; Wang, Tai; Yan, Xiufeng; Dai, Shaojun

    2010-12-03

    Drought is one of the most severe limitations to plant growth and productivity. Resurrection plants have evolved a unique capability to tolerate desiccation in vegetative tissues. Fern-ally Selaginella tamariscina (Beauv.) is one of the most primitive vascular resurrection plants, which can survive a desiccated state and recover when water becomes available. To better understand the mechanism of desiccation tolerance, we have applied physiological and proteomic analysis. Samples of S. tamariscina were water-deprived for up to seven days followed by 12 h of rewatering. Our results showed that endogenous abscisic acid (ABA) increased to regulate dehydration-responsive genes/proteins and physiological processes. In the course of dehydration, the contents of osmolytes represented by soluble sugars and proline were increased to maintain cell structure integrity. The activities of four antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione reductase (GR)) also increased. In contrast, both the rate of photosynthesis and the chlorophyll content decreased, and plasma membrane integrity was lost. We identified 138 desiccation-responsive two-dimensional electrophoresis (2-DE) spots, representing 103 unique proteins. Hierarchical clustering analysis revealed that 83% of the proteins were down-regulated upon dehydration. They were mainly involved in photosynthesis, carbohydrate and energy metabolism, stress and defense, protein metabolism, signaling, membrane/transport, cell structure, and cell division. The dynamic expression changes of the desiccation-responsive proteins provide strong evidence that cell structure modification, photosynthesis reduction, antioxidant system activation, and protein post-transcriptional/translational modifications are essential to the poikilochlorophyllous fern-ally S. tamariscina in response to dehydration. In addition, our comparative analysis of dehydration-responsive proteins in vegetative tissues

  16. First megafossil evidence of Cyatheaceous tree fern from the Indian Cenozoic

    Science.gov (United States)

    Bera, Subir; Gupta, Sudha; Khan, Mahasin Ali; De, Aniruddha; Mukhopadhyay, Radhanath

    2014-08-01

    A part of the compressed tree fern axis with leaf and adventitious root scars in unusual arrangement from Plio-Pleistocene sediments of Arunachal Pradesh, India is described as Cyathea siwalika sp. nov. This record suggests that Cyathea was an important component of tropical evergreen forest in the area during the Plio-Pleistocene and this group subsequently declined in importance within the local vegetation.

  17. A new population of Aleutian shield fern (Polystichum aleuticum C. Christens.) on Adak Island, Alaska

    Science.gov (United States)

    Talbot, Sandra L.; Talbot, Stephen S.

    2002-01-01

    We report and describe a new population of the endangered Aleutian shield fern (Polystichum aleuticum C. Christens.) discovered on Mount Reed, Adak Island, Alaska. The new population is located at a lower elevation than the other known populations, placing the species' known elevational range between 338 m and 525 m. The discovery of this population is significant because it increases the total number of known populations and individuals for the species.

  18. Gene flow among populations of two rare co-occurring fern species differing in ploidy level.

    Science.gov (United States)

    Bucharová, Anna; Münzbergová, Zuzana

    2012-01-01

    Differences in ploidy levels among different fern species have a vast influence on their mating system, their colonization ability and on the gene flow among populations. Differences in the colonization abilities of species with different ploidy levels are well known: tetraploids, in contrast to diploids, are able to undergo intra-gametophytic selfing. Because fertilization is a post-dispersal process in ferns, selfing results in better colonization abilities in tetraploids because of single spore colonization. Considerably less is known about the gene flow among populations of different ploidy levels. The present study examines two rare fern species that differ in ploidy. While it has already been confirmed that tetraploid species are better at colonizing, the present study focuses on the gene flow among existing populations. We analyzed the genetic structure of a set of populations in a 10×10 km study region using isoenzymes. Genetic variation in tetraploid species is distributed mainly among populations; the genetic distance between populations is correlated with the geographical distance, and larger populations host more genetic diversity than smaller populations. In the diploid species, most variability is partitioned within populations; the genetic distance is not related to geographic distance, and the genetic diversity of populations is not related to the population size. This suggests that in tetraploid species, which undergo selfing, gene flow is limited. In contrast, in the diploid species, which experience outcrossing, gene flow is extensive and the whole system behaves as one large population. Our results suggest that in ferns, the ability to colonize new habitats and the gene flow among existing populations are affected by the mating system.

  19. New Fern Materials from Guizhou%贵州蕨类植物新资料

    Institute of Scientific and Technical Information of China (English)

    潘炉台; 赵俊华; 王培善

    2011-01-01

    Tectaria yunnanensis (Bak.) Ching, a new recorded fern species in Guizhou and a new variety,Pteris deltodon Bak. var. monstrosa P. S. Wang et J. H. Zhao collected by the authors are now delivered as follows.%报道了贵州一新记录蕨类植物种--云南三叉蕨和一新变种--畸形岩凤尾蕨.

  20. Horsetails are the sister group to all other monilophytes and Marattiales are sister to leptosporangiate ferns.

    Science.gov (United States)

    Knie, Nils; Fischer, Simon; Grewe, Felix; Polsakiewicz, Monika; Knoop, Volker

    2015-09-01

    The "Monilophyte" clade comprising ferns, horsetails and whisk ferns receives unequivocal support from molecular data as the sister clade to seed plants. However, the branching order of its earliest emerging lineages, the Equisetales (horsetails), the Marattiales, the Ophioglossales/Psilotales and the large group of leptosporangiate ferns has remained dubious. We investigated the mitochondrial nad2 and rpl2 genes as two new, intron-containing loci for a wide sampling of taxa. We found that both group II introns - nad2i542g2 and rpl2i846g2 - are universally present among monilophytes. Both introns have orthologues in seed plants where nad2i542g2 has evolved into a trans-arrangement. In contrast and despite substantial size extensions to more than 5kb in Psilotum, nad2i542g2 remains cis-arranged in the monilophytes. For phylogenetic analyses, we filled taxonomic gaps in previously investigated mitochondrial (atp1, nad5) and chloroplast (atpA, atpB, matK, rbcL, rps4) loci and created a 9-gene matrix that also included the new mitochondrial nad2 and rpl2 loci. We extended the taxon sampling with two taxa each for all land plant outgroups (liverworts, mosses, hornworts, lycophytes and seed plants) to minimize the risk of phylogenetic artefacts. We ultimately obtained a well-supported molecular phylogeny placing Marattiales as sister to leptosporangiate ferns and horsetails as sister to all remaining monilophytes. In addition, an indel in an exon of the here introduced rpl2 locus independently supports the placement of horsetails. We conclude that under dense taxon sampling, phylogenetic information from a prudent choice of loci is currently superior to character-rich phylogenomic approaches at low taxon sampling. As here shown the selective choice of loci and taxa enabled us to resolve the long-enigmatic diversifications of the earliest monilophyte lineages.

  1. Juan Caramuel y la probable arquitectura. Jorge Fernández-Santos

    OpenAIRE

    Gil Saura, Yolanda

    2016-01-01

    Reseña del libro de Jorge Fernández-Santos Ortiz-Iribas, Juan Caramuel y la probable arquitectura. Centro de Estudios Europa Hispánica, Madrid, 2014, 592 págs., 114 ilustraciones en color. Analiza la aportación del libro en relación a la historiografía de la arquitectura barroca española.

  2. Distribution, habitat preferences and population sizes of two threatened tree ferns, Cyathea cunninghamii and Cyathea x marcescens, in south-eastern Australia

    OpenAIRE

    Peacock, Ross J.; Downing, Alison; Brownsey, Patrick; Cameron, David

    2013-01-01

    The distribution, population sizes and habitat preferences of the rare tree ferns Cyathea cunninghamii Hook.f. (Slender Tree Fern) and F1 hybrid Cyathea x marcescens N.A.Wakef. (Skirted Tree Fern) in south-eastern Australia are described, together with the extension of the known distribution range of Cyathea cunninghamii from eastern Victoria into south-eastern New South Wales. Floristic and ecological data, encompassing most of the known habitat types, vegetation associations and population ...

  3. The Enrichment and Transfer of Heavy Metals for Two Ferns in Pb-Zn Tailing

    Directory of Open Access Journals (Sweden)

    Mai Jiajie

    2017-01-01

    Full Text Available The enrichment and transfer of 8 heavy metals of Equisetum ramosissimum and Pteris vittata growing naturally close to edge of the sewage pool in Bencun Pb-Zn Tailing, Eastern Guangdong were investigated. The results indicated that the pollution of Cd, Pb, Hg, Zn was very severe in this tailing, followed by Cu and Mn. The potential ecological risk of heavy metals was assessed to be very strong based on soil background values of Guangdong Province and at high risk according to criteria of the second grade State Soil Environmental Quality Standard, and Cd, Hg, Pb were the main factors leading to potential ecological risk. The content of 8 heavy metals in the two ferns did not reach critical content of hyperaccumulator, so neither of them was typical hyperaccumulator, but both had a certain tolerance to these heavy metal pollution. Underground parts of Pteris vittata had an enrichment coefficient above 1 and that of Equisetum ramosissimum had a value near 1, therefore the two ferns could be utilized as potential enrichment plants. The two ferns have strong adaptability to the tailing habitat and can be used as pioneers in ecological restoration of Pb-Zn tailings.

  4. The accumulation and subcellular distribution of arsenic and antimony in four fern plants.

    Science.gov (United States)

    Feng, R; Wang, X; Wei, C; Tu, S

    2015-01-01

    In the present study, Pteris cretica 'Albo-Lineata' (PC), Pteris fauriei (PF), Humata tyermanii Moore (HT), and Pteris ensiformis Burm (PE), were selected to explore additional plant materials for the phytoremediation of As and Sb co-contamination. To some extent, the addition of As and Sb enhanced the growth of HT, PE, and PF. Conversely, the addition of As and Sb negatively affected the growth of PC and was accompanied with the accumulation of high levels of As and Sb in the roots. The highest concentration of Sb was recorded as 6405 mg kg(-1) in the roots of PC, and that for As was 337 mg kg(-1) in the rhizome of PF. To some degree, As and Sb stimulated the uptake of each other in these ferns. Arsenic was mainly stored in the cytoplasmic supernatant (CS) fraction, followed by the cell wall (CW) fraction. In contrast, Sb was mainly found in the CW fraction and, to a lesser extent, in the CS fraction, suggesting that the cell wall and cytosol play different roles in As and Sb accumulation by fern plants. This study demonstrated that these fern plants show a good application potential in the phytoremediation of As and Sb co-contaminated environments.

  5. Mycorrhizal fungi modify element distribution in gametophytes and sporophytes of a fern Pellaeaviridis from metaliferous soils.

    Science.gov (United States)

    Turnau, Katarzyna; Przybyłowicz, Wojciech J; Ryszka, Przemysław; Orłowska, Elżbieta; Anielska, Teresa; Mesjasz-Przybyłowicz, Jolanta

    2013-08-01

    In the present study, the element distribution within mycothallic and nonmycothallic gametophytes and the early stages of sporophyte development of Pellaea viridis (Pteridaceae) were investigated. Gametophytes of this fern were collected from soil samples originating in the ultramafic area of the Agnes Mine near Barberton, South Africa. The gametophytes were grown on both the original soil and on a plant growth substratum obtained from the local botanical garden. Gametophytes and young sporophytes grown on substratum inoculated with Glomus tenue or non-inoculated were freeze-dried, and the distribution of elements was studied using micro-PIXE. The GeoPIXE II software package was used for quantitative elemental mapping complemented by data extracted from arbitrarily selected micro-areas. The obtained results suggest that although the fern itself avoids the uptake of large amounts of heavy metals, increased levels of Ni, Cr, Fe, Co and Ti were found in the part of the gametophyte that hosted the fungal endophyte. This finding suggests that the fungus might be active in the immobilisation of certain potentially toxic metals that are taken up from the soil by the plant, although other mechanisms cannot be excluded. For the first time, precise, quantitative measurements of the concentration of individual elements in the fern gametophytes and young sporophytes were obtained, along with their distribution within the plant parts.

  6. Fern and lycophyte guard cells do not respond to endogenous abscisic acid.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2012-04-01

    Stomatal guard cells regulate plant photosynthesis and transpiration. Central to the control of seed plant stomatal movement is the phytohormone abscisic acid (ABA); however, differences in the sensitivity of guard cells to this ubiquitous chemical have been reported across land plant lineages. Using a phylogenetic approach to investigate guard cell control, we examined the diversity of stomatal responses to endogenous ABA and leaf water potential during water stress. We show that although all species respond similarly to leaf water deficit in terms of enhanced levels of ABA and closed stomata, the function of fern and lycophyte stomata diverged strongly from seed plant species upon rehydration. When instantaneously rehydrated from a water-stressed state, fern and lycophyte stomata rapidly reopened to predrought levels despite the high levels of endogenous ABA in the leaf. In seed plants under the same conditions, high levels of ABA in the leaf prevented rapid reopening of stomata. We conclude that endogenous ABA synthesized by ferns and lycophytes plays little role in the regulation of transpiration, with stomata passively responsive to leaf water potential. These results support a gradualistic model of stomatal control evolution, offering opportunities for molecular and guard cell biochemical studies to gain further insights into stomatal control.

  7. Cytological features of oogenesis and their evolutionary significance in the fern Osmunda japonica.

    Science.gov (United States)

    Cao, Jian-Guo; Dai, Xiao-Fei; Wang, Quan-Xi

    2012-03-01

    The development of the egg and canal cells in the fern Osmunda japonica Thunb. was studied during oogenesis by transmission electron microscopy. The mature egg possesses no fertilization pore and no typical egg envelope. In addition, an extra wall formed around the canal cells during oogenesis and apparently blocked protoplasmic connections between the egg and the canal cells. The periodic acid Schiff (PAS) reaction revealed that the extra wall was most likely composed of polysaccharides. Maturation of the egg was accompanied by the formation of a separation cavity above the egg and by some changes in the morphology of the nucleus and cytoplasmic organelles. The chromatin of the nucleus becomes condensed and the upper surface of the nucleus becomes closely associated with the plasmalemma. Amyloplasts in the egg cytoplasm were numerous and conspicuous, with most in close proximity to the nucleus. Finally, the cytoplasm on one side of the egg became vesiculated and the overlying plasmalemma was easily disrupted. These cytological features of the egg and the canal cells during oogenesis in O. japonica are markedly different from those of the leptosporangiate ferns and suggest a significant evolutionary divergence in reproductive cellular features between Osmundaceae and leptosporangiate ferns.

  8. The distribution of TPX2 in dividing leaf cells of the fern Asplenium nidus.

    Science.gov (United States)

    Panteris, E; Adamakis, I-D S; Chanoumidou, K

    2013-01-01

    Plant cell division requires the dynamic organisation of several microtubule arrays. The mechanisms of regulation of the above arrays are under rigorous research. Among several factors that are involved in plant microtubule dynamics, the Targeting Protein for Xklp2 (TPX2) has been found to play a role in spindle organisation, in combination with Aurora kinases, in dividing cells of angiosperms. Microtubule organisation in dividing cells of ferns exhibits certain peculiarities. Accordingly, the presence and distribution of a TPX2 homologue might be helpful in understanding the patterns and regulatory mechanisms of microtubule arrays in this plant group. In this study, a putative TPX2 homologue was identified using Western blotting in the fern Asplenium nidus. It was found, using immunostaining and CLSM, that it is co-localised with perinuclear preprophase microtubules and the prophase spindle, and follows the microtubule pattern during metaphase/anaphase and telophase. During cytokinesis, while in angiosperms TPX2 is degraded, in A. nidus the TPX2 signal persists, co-localising with the phragmoplast. In early post-cytokinetic cells, a TPX2 signal is present on the nuclear surface facing the daughter cell wall and, thereafter it is co-localised with the fern-specific microtubule aggregation that lines the new wall, which is possibly involved in cortical microtubule assembly.

  9. A phytotoxic active substance in the decomposing litter of the fern Gleichenia japonica.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Saito, Yoshihumi; Ohno, Osamu; Suenaga, Kiyotake

    2015-03-15

    The fern Gleichenia japonica often dominates plant communities by forming large monospecific stands throughout the temperate to tropical Asia. The objective of this study was the investigation of allelopathic property and substances of the decomposing litter of the fern to evaluate the possible involvement of its allelopathy in the domination. An aqueous methanol extract of G. japonica litter inhibited the growth of garden cress (Lepidium sativum), lettuce (Lactuca sativa), barnyard grass (Echinochloa crus-galli), and ryegrass (Lolium multiflorum). This result suggests that G. japonica litter contains growth inhibitory substances. The extract was purified by chromatography while monitoring the inhibitory activity, and a growth inhibitory substance was isolated. The chemical structure of the substance was determined by spectral data to be a novel compound, 13-O-β-fucopyranosyl-3β-hydroxymanool. This compound inhibited root and shoot growth of garden cress and barnyard grass at concentrations ranging from 89.7 to 271 μM for 50% inhibition. In addition, the compound had potent growth inhibitory activity with the soil taken from near the colony. The concentration of the compound in soil under a pure colony of G. japonica was 790 μM, suggesting that the compound may contribute to the establishment of monocultural stands by this fern.

  10. Not dead yet: the seasonal water relations of two perennial ferns during California's exceptional drought.

    Science.gov (United States)

    Baer, Alex; Wheeler, James K; Pittermann, Jarmila

    2016-04-01

    The understory of the redwood forests of California's coast harbors perennial ferns, including Polystichum munitum and Dryopteris arguta. Unusual for ferns, these species are adapted to the characteristic Mediterranean-type dry season, but the mechanisms of tolerance have not been studied. The water relations of P. munitum and D. arguta were surveyed for over a year, including measures of water potential (Ψ), stomatal conductance (gs) and frond stipe hydraulic conductivity (K). A dehydration and re-watering experiment on potted P. munitum plants corroborated the field data. The seasonal Ψ varied from 0 to below -3 MPa in both species, with gs and K generally tracking Ψ; the loss of K rarely exceeded 80%. Quantile regression analysis showed that, at the 0.1 quantile, 50% of K was lost at -2.58 and -3.84 MPa in P. munitum and D. arguta, respectively. The hydraulic recovery of re-watered plants was attributed to capillarity. The seasonal water relations of P. munitum and D. arguta are variable, but consistent with laboratory-based estimates of drought tolerance. Hydraulic and Ψ recovery following rain allows perennial ferns to survive severe drought, but prolonged water deficit, coupled with insect damage, may hamper frond survival. The legacy effects of drought on reproductive capacity and community dynamics are unknown.

  11. Physicochemical characterisation of the ubiquitous bracken fern as useful biomaterial for preconcentration of heavy metals.

    Science.gov (United States)

    Barriada, Jose L; Caridad, Sergio; Lodeiro, Pablo; Herrero, Roberto; Sastre de Vicente, Manuel E

    2009-02-01

    Batch experiments with dry bracken fern have been done to determine cadmium and lead sequestering capacity of this biomaterial. Biomass characterisation was done by infrared spectroscopy and potentiometric analysis. The effect of pH of the metal containing solution, contact time and initial metal concentration has been studied, together with the acid-base properties of the biomaterial. Results obtained have been analysed using mathematical and modelling techniques. Effect of pH on metal sequestration has been correlated with observed acid-base properties of the natural substrate. Kinetic data analysis provided relevant information about metal sequestration rate, showing important differences between lead and cadmium. Maximum uptake was found to be the same for both metals 0.410 mmol/g. This value was also clearly correlated to the number of acidic groups determined for this material which was found to be 0.432 mmol of acidic groups per gram of fern. Results obtained indicate that acidic groups are the functional groups responsible of the sequestration of metal ions and that bracken fern is a promising material for metal preconcentration.

  12. Absorption of Hazardous Pollutants by a Medicinal Fern Blechnum orientale L.

    Directory of Open Access Journals (Sweden)

    Xiao-min Zhu

    2013-01-01

    Full Text Available A Chinese medicinal fern Blechnum orientale (Linn was separately collected from polluted and unpolluted sites to determine whether it could accumulate hazardous pollutants or not. Metal concentrations (Cu, Zn, Mn, Pb, Cd, Cr, As, and Hg both in the fronds and roots and polycyclic aromatic hydrocarbons (PAHs in the fronds of this fern were quantified. At both sites, roots of B. orientale had significantly higher heavy metals than the fronds. Concentrations of Pb, As, Hg, Cd, and Cu in the fronds at the polluted site were more than 2, 6, 7, 14, 5, and 13 times of those at the unpolluted site. Translocation factor and bioaccumulation factor implied that B. orientale did not have a good ability to transport heavy metals from the roots to the fronds. Total PAHs in the fronds at the polluted site were significantly higher than those at the unpolluted site, indicating the physiological PAHs absorption by B. orientale growing at polluted sites. Uptake of pollutants via stomata might be the main reason causing the significant accumulation of hazardous pollutants in the fronds of B. orientale. Large-scale systematical survey and intensive monitoring on pollutants in this medicinal fern should be necessarily strengthened.

  13. The development of gametophytes and its' antheridiogen system of Dryopteris erythrosora%红盖鳞毛蕨配子体发育及其成精子囊素系统的研究

    Institute of Scientific and Technical Information of China (English)

    王力超; 刘沨; 曹建国; 戴锡玲

    2012-01-01

    The effects of light and darkness on spore germination percentage of the fern Dryopteris erythrosora are investigated. Moreover,the effects of antheridiogen of D. Erythrosora on its' spores germination and gametophyte development and on spores germination, gametophyte development of Ceratopteris thalictroides are investigated respectively. The results exhibit: ① The light illumination is not the prerequisite of spore germination of D. Erythrosora. However, the light can markedly promote the spore germination. ② In light condition, antheridiogen of D. Erythrosora promotes the spore germination and the development of the male gametophytes,but inhibits the development of the bisexual gametophytes. But in darkness,the antheridiogen does not promote the spore germination. ③ The antheridiogen of D. Erythrosora at different stage of gametophyte development exhibits no obvious effects on the spores germination and gametophyte development of Ceratopteris.%研究了光照和黑暗条件对红盖鳞毛蕨孢子萌发率的影响,同时研究了红盖鳞毛蕨成精子囊素对其孢子萌发和配子体发育的影响以及红盖鳞毛蕨成精子囊素对水蕨孢子萌发和配子体发育的影响.实验表明:①光照不是红盖鳞毛蕨孢子萌发的必要条件,但能显著促进其萌发;②在光照条件下,红盖鳞毛蕨成精子囊素可促进其孢子萌发和雄配子体发育;在黑暗条件下不能促进其孢子萌发;③红盖鳞毛蕨配子体各发育时期产生的成精子囊素对水蕨孢子萌发和配子体发育均无显著影响.

  14. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island, Sea of East Japan, Based on Chloroplast Genome Sequencing.

    Science.gov (United States)

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  15. Evolution of the rpoB-psbZ region in fern plastid genomes: notable structural rearrangements and highly variable intergenic spacers

    Directory of Open Access Journals (Sweden)

    Su Ying-Juan

    2011-04-01

    Full Text Available Abstract Background The rpoB-psbZ (BZ region of some fern plastid genomes (plastomes has been noted to go through considerable genomic changes. Unraveling its evolutionary dynamics across all fern lineages will lead to clarify the fundamental process shaping fern plastome structure and organization. Results A total of 24 fern BZ sequences were investigated with taxon sampling covering all the extant fern orders. We found that: (i a tree fern Plagiogyria japonica contained a novel gene order that can be generated from either the ancestral Angiopteris type or the derived Adiantum type via a single inversion; (ii the trnY-trnE intergenic spacer (IGS of the filmy fern Vandenboschia radicans was expanded 3-fold due to the tandem 27-bp repeats which showed strong sequence similarity with the anticodon domain of trnY; (iii the trnY-trnE IGSs of two horsetail ferns Equisetum ramosissimum and E. arvense underwent an unprecedented 5-kb long expansion, more than a quarter of which was consisted of a single type of direct repeats also relevant to the trnY anticodon domain; and (iv ycf66 has independently lost at least four times in ferns. Conclusions Our results provided fresh insights into the evolutionary process of fern BZ regions. The intermediate BZ gene order was not detected, supporting that the Adiantum type was generated by two inversions occurring in pairs. The occurrence of Vandenboschia 27-bp repeats represents the first evidence of partial tRNA gene duplication in fern plastomes. Repeats potentially forming a stem-loop structure play major roles in the expansion of the trnY-trnE IGS.

  16. Different slopes of a mountain can determine the structure of ferns and lycophytes communities in a tropical forest of Brazil

    Directory of Open Access Journals (Sweden)

    FELIPE C. NETTESHEIM

    2014-03-01

    Full Text Available A community of Ferns and Lycophytes was investigated by comparing the occurrence of species on different slopes of a paleoisland in Southeastern Brazil. Our goal was to evaluate the hypothesis that slopes with different geographic orientations determine a differentiation of Atlantic Forest ferns and lycophytes community. We recorded these plants at slopes turned towards the continent and at slopes turned towards the open sea. Analysis consisted of a preliminary assessment on fern beta diversity, a Non Metric Multidimensional Scaling (NMDS and a Student t-test to confirm if sites sampling units ordination was different at each axis. We further used the Pearson coefficient to relate fern species to the differentiation pattern and again Student's t-test to determine if richness, plant cover and abundance varied between the two sites. There was a relatively low number of shared species between the two sites and ferns and lycophytes community variation was confirmed. Some species were detected as indicators of the community variation but we were unable to detect richness, plant cover or abundance differences. Despite the evidence of this variation between the slopes, further works are needed to evaluate which processes are contributing to determine this pattern.

  17. Different slopes of a mountain can determine the structure of ferns and lycophytes communities in a tropical forest of Brazil.

    Science.gov (United States)

    Nettesheim, Felipe C; Damasceno, Elaine R; Sylvestre, Lana S

    2014-03-01

    A community of Ferns and Lycophytes was investigated by comparing the occurrence of species on different slopes of a paleoisland in Southeastern Brazil. Our goal was to evaluate the hypothesis that slopes with different geographic orientations determine a differentiation of Atlantic Forest ferns and lycophytes community. We recorded these plants at slopes turned towards the continent and at slopes turned towards the open sea. Analysis consisted of a preliminary assessment on fern beta diversity, a Non Metric Multidimensional Scaling (NMDS) and a Student t-test to confirm if sites sampling units ordination was different at each axis. We further used the Pearson coefficient to relate fern species to the differentiation pattern and again Student's t-test to determine if richness, plant cover and abundance varied between the two sites. There was a relatively low number of shared species between the two sites and ferns and lycophytes community variation was confirmed. Some species were detected as indicators of the community variation but we were unable to detect richness, plant cover or abundance differences. Despite the evidence of this variation between the slopes, further works are needed to evaluate which processes are contributing to determine this pattern.

  18. Clastogenic effect of bracken fern (Pteridium aquilinum v. arachnoideum) diet in peripheral lymphocytes of human consumers: preliminary data.

    Science.gov (United States)

    Recouso, R C; Stocco dos Santos, R C; Freitas, R; Santos, R C; de Freitas, A C; Brunner, O; Beçak, W; Lindsey, C J

    2003-03-01

    Ingestion of bracken fern (Pteridium aquilinum v. arachnoideum) is associated with digestive tract cancer in different regions of Japan, Venezuela and Brazil. In view of reports that dietary bracken fern causes chromosomal instability in cattle, the clastogenic effect of bracken fern was investigated, in a preliminary study, in peripheral lymphocytes obtained from habitual consumers and a control group of non-consumers, which were carefully investigated about cancer history or family cancer history, negative in both cases, using protocols comparable to those previously described in studies in cattle raised on bracken pastures. Cytogenetic analysis showed significant increased levels of chromosomal abnormalities, such as chromatid breaks, in cultured peripheral lymphocytes of the consumer group. There was no correlation with subjects, gender, smoking habits or alcohol consumption, and the only correlation was with prolonged exposure to dietary bracken.

  19. Population genetic variation in the tree fern Alsophila spinulosa (Cyatheaceae: effects of reproductive strategy.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available BACKGROUND: Essentially all ferns can perform both sexual and asexual reproduction. Their populations represent suitable study objects to test the population genetic effects of different reproductive systems. Using the diploid homosporous fern Alsophila spinulosa as an example species, the main purpose of this study was to assess the relative impact of sexual and asexual reproduction on the level and structure of population genetic variation. METHODOLOGY/PRINCIPAL FINDINGS: Inter-simple sequence repeats analysis was conducted on 140 individuals collected from seven populations (HSG, LCH, BPC, MPG, GX, LD, and ZHG in China. Seventy-four polymorphic bands discriminated a total of 127 multilocus genotypes. Character compatibility analysis revealed that 50.0 to 70.0% of the genotypes had to be deleted in order to obtain a tree-like structure in the data set from populations HSG, LCH, MPG, BPC, GX, and LD; and there was a gradual decrease of conflict in the data set when genotypes with the highest incompatibility counts were successively deleted. In contrast, in population ZHG, only 33.3% of genotypes had to be removed to achieve complete compatibility in the data set, which showed a sharp decline in incompatibility upon the deletion of those genotypes. All populations examined possessed similar levels of genetic variation. Population ZHG was not found to be more differentiated than the other populations. CONCLUSIONS/SIGNIFICANCE: Sexual recombination is the predominant source of genetic variation in most of the examined populations of A. spinulosa. However, somatic mutation contributes most to the genetic variation in population ZHG. This change of the primary mode of reproduction does not cause a significant difference in the population genetic composition. Character compatibility analysis represents an effective approach to separate the role of sexual and asexual components in shaping the genetic pattern of fern populations.

  20. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

    Science.gov (United States)

    Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

    2016-01-01

    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

  1. De novo transcriptome assembly of a fern, Lygodium japonicum, and a web resource database, Ljtrans DB.

    Science.gov (United States)

    Aya, Koichiro; Kobayashi, Masaaki; Tanaka, Junmu; Ohyanagi, Hajime; Suzuki, Takayuki; Yano, Kenji; Takano, Tomoyuki; Yano, Kentaro; Matsuoka, Makoto

    2015-01-01

    During plant evolution, ferns originally evolved as a major vascular plant with a distinctive life cycle in which the haploid and diploid generations are completely separated. However, the low level of genetic resources has limited studies of their physiological events, as well as hindering research on the evolutionary history of land plants. In this study, to identify a comprehensive catalog of transcripts and characterize their expression traits in the fern Lygodium japonicum, nine different RNA samples isolated from prothalli, trophophylls, rhizomes and sporophylls were sequenced using Roche 454 GS-FLX and Illumina HiSeq sequencers. The hybrid assembly of the high-quality 454 GS-FLX and Illumina HiSeq reads generated a set of 37,830 isoforms with an average length of 1,444 bp. Using four open reading frame (ORF) predictors, 38,142 representative ORFs were identified from a total of 37,830 transcript isoforms and 95 contigs, which were annotated by searching against several public databases. Furthermore, an orthoMCL analysis using the protein sequences of L. japonicum and five model plants revealed various sets of lineage-specific genes, including those detected among land plant lineages and those detected in only L. japonicum. We have also examined the expression patterns of all contigs/isoforms, along with the life cycle of L. japonicum, and identified the tissue-specific transcripts using statistical expression analyses. Finally, we developed a public web resource, the L. japonicum transcriptome database at http://bioinf.mind.meiji.ac.jp/kanikusa/, which provides important opportunities to accelerate molecular research in ferns.

  2. Fern-synthesized silver nanocrystals: Towards a new class of mosquito oviposition deterrents?

    Science.gov (United States)

    Rajaganesh, Rajapandian; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Jayashanthini, Sudalaimani; Aziz, Al Thbiani; Roni, Mathath; Suresh, Udaiyan; Trivedi, Subrata; Rehman, Hasibur; Higuchi, Akon; Nicoletti, Marcello; Benelli, Giovanni

    2016-12-01

    Mosquitoes act as vectors of devastating pathogens and parasites, representing a key threat for millions of humans and animals worldwide. Eco-friendly control tools are urgently required. We proposed a novel method of fern-mediated biosynthesis of silver nanoparticles (AgNP) using Dicranopteris linearis, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), zeta potential and particle size analysis. In mosquitocidal assays, the LC50 of D. linearis extract against Aedes aegypti ranged from 165.213 (larva I) to 255.055ppm (pupa). LC50 of D. linearis-synthesized AgNP ranged from 18.905 (larva I) to 29.328ppm (pupa). In the field, the application of D. linearis extract and AgNP (10×LC50) led to 100% larval reduction after 72h. Smoke toxicity experiments conducted against A. aegypti adults showed that D. linearis leaf-, stem- and root-based coils evoked mortality rates comparable to the permethrin-based positive control (58%, 47%, 34%, and 48% respectively). In ovicidal experiments, egg hatchability was reduced by 100% after treatment with 25ppm of AgNP and 300ppm of D. linearis extract. Interestingly, oviposition deterrent assays highlighted that 100ppm of fern extract reduced oviposition rates of more than 65%, while 10ppm of fern-fabricated AgNP reduced oviposition rates of more than 70% in A. aegypti (OAI were -0.52 and -0.55, respectively). Overall, our results highlighted that D. linearis-synthesized AgNP could be useful candidates to develop nano-formulated oviposition deterrents effective against dengue vectors.

  3. Antibody-based screening of cell wall matrix glycans in ferns reveals taxon, tissue and cell-type specific distribution patterns

    DEFF Research Database (Denmark)

    Leroux, Olivier; Sørensen, Iben; Marcus, Susan E.;

    2015-01-01

    plants, ferns have been largely neglected in cell wall comparative studies. Results: To explore fern cell wall diversity sets of monoclonal antibodies directed to matrix glycans of angiosperm cell walls have been used in glycan microarray and in situ analyses with 76 fern species and four species...... across the ferns and specifically associated with phloem cell walls and similarly the LM11 xylan epitope was associated with xylem cell walls. The LM5 galactan and LM6 arabinan epitopes, linked to pectic supramolecules in angiosperms, were associated with vascular structures with only limited detection...... in ground tissues. Mannan epitopes were found to be associated with the development of mechanical tissues. We provided the first evidence for the presence of MLG in leptosporangiate ferns. Conclusions: The data sets indicate that cell wall diversity in land plants is multifaceted and that matrix glycan...

  4. The physiological resilience of fern sporophytes and gametophytes: advances in water relations offer new insights into an old lineage

    Directory of Open Access Journals (Sweden)

    Jarmila ePittermann

    2013-08-01

    Full Text Available Ferns are some of the oldest vascular plants in existence and they are the second most diverse lineage of tracheophytes next to angiosperms. Recent efforts to understand fern success have fo-cused on the physiological capacity and stress tolerance of both the sporophyte and the gameto-phyte generations. In this review, we examine these insights through the lens of plant water rela-tions, focusing primarily on the form and function of xylem tissue in the sporophyte, as well as the tolerance to and recovery from drought and desiccation stress in both stages of the fern life cycle. The absence of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes. Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and vari-ously sized megaphylls are shared between ferns and more derived lineages, and offer an oppor-tunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Fern gametophytes show a high degree of desiccation tolerance but new evidence shows that morphological attributes in the gametophytes may facilitate water retention, though little work has addressed the ecological significance of this variation. We conclude with an emergent hypothesis that selection acted on the physiology of both the sporophyte and gameto-phyte generations in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic.

  5. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica.

    Science.gov (United States)

    Sosa, Victoria; Ornelas, Juan Francisco; Ramírez-Barahona, Santiago; Gándara, Etelvina

    2016-01-01

    Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted species remained in situ or expanded to the lowlands during glacial cycles and contracted allopatrically during the interglacials. Although the observed genetic signals of population size changes of cloud forest-adapted species including tree ferns correspond to predicted changes by Pleistocene climate change dynamics, the observed patterns of intraspecific lineage divergence showed temporal incongruence. Here we combined phylogenetic analyses, ancestral area reconstruction, and divergence time estimates with climatic and altitudinal data (environmental space) for phenotypic traits of tree fern species to make inferences about evolutionary processes in deep time. We used phylogenetic Bayesian inference and geographic and altitudinal distribution of tree ferns to investigate ancestral area and elevation and environmental preferences of Mesoamerican tree ferns. The phylogeny was then used to estimate divergence times and ask whether the ancestral area and elevation and environmental shifts were linked to climatic events and historical climatic preferences. Bayesian trees retrieved Cyathea, Alsophyla, Gymnosphaera and Sphaeropteris in monophyletic clades. Splits for species in these genera found in Mesoamerican cloud forests are recent, from the Neogene to the Quaternary, Australia was identified as the ancestral area for the clades of these genera, except for Gymnosphaera that was Mesoamerica. Climate tolerance was not divergent from hypothesized ancestors for the most significant

  6. Effect of habitat preference on frond life span in three Cyathea tree ferns

    Science.gov (United States)

    Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

    2013-04-01

    It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 ± 14.10 , 7.0 ± 3.07 and 5.0 ± 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 ± 4.12 months) than the two others (C. lepifera (6.8 ± 1.29 months) and C. spinulosa (7.3 ±1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 ± 1.34, 8.27 ± 0.69, and 6.34 ± 0.54 μmol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 ± 1.95), which was followed by C. spinulosa (18.58 ± 1.37) and C. lepifera (18.68 ± 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span

  7. Fossilized nuclei and chromosomes reveal 180 million years of genomic stasis in royal ferns.

    Science.gov (United States)

    Bomfleur, Benjamin; McLoughlin, Stephen; Vajda, Vivi

    2014-03-21

    Rapidly permineralized fossils can provide exceptional insights into the evolution of life over geological time. Here, we present an exquisitely preserved, calcified stem of a royal fern (Osmundaceae) from Early Jurassic lahar deposits of Sweden in which authigenic mineral precipitation from hydrothermal brines occurred so rapidly that it preserved cytoplasm, cytosol granules, nuclei, and even chromosomes in various stages of cell division. Morphometric parameters of interphase nuclei match those of extant Osmundaceae, indicating that the genome size of these reputed "living fossils" has remained unchanged over at least 180 million years-a paramount example of evolutionary stasis.

  8. Conocer el Nuevo Mundo: referencialidad en las ilustraciones de Fernández de Oviedo

    OpenAIRE

    Teglia, Vanina M.

    2014-01-01

    Las ilustraciones realizadas por el cronista oficial de Indias Gonzalo Fernández de Oviedo para sus apartados sobre la flora americana son las primeras de este tipo aparecidas mundialmente en una edición impresa. Entre los paradigmas del saber libresco medieval y el de la creciente valoración del testimonio de vista, el Veedor del Oro en el Nuevo Mundo, escritor y dibujante, recurre a las herramientas del lenguaje visual para, por un lado, ofrecer pruebas fehacientes de la naturaleza que esta...

  9. León Fernández Bonilla y la historiografía costarricense.

    OpenAIRE

    Quesada Camacho, Juan Rafael

    2011-01-01

    Se ha afirmado, con gran justicia que León Fernández Bonilla fue el fundador del Archivo Nacional, “granero” del historiador”, según la hermosa metáfora de Lucien Febvre. En efecto, don León, como se ha acostumbrado llamarlo, ocupó un lugar de primer orden en el origen de los estudios históricos en Costa Rica. ¿En qué contexto se dio su contribución a la historiografía costarricense?

  10. Genetic and Molecular Dissection of Arsenic Hyperaccumulation in the fern Pteris vittata.

    Energy Technology Data Exchange (ETDEWEB)

    Jo Ann Banks; David Salt

    2008-04-04

    Pteris vittata is a fern that is extraordinary in its ability to tolerate hyperaccumulate high levels of arsenic (As). The goals of the proposed research, to identify the genes that are necessary for As hyperaccumulation in P. vittata using molecular and genetic approaches and to understand the physiology of arsenic uptake and distribution in the living plant, were accomplished during the funding period. The genes that have been identified may ultimately enable the engineering or selection of other plants capable of As hyperaccumulation. This is important for the phytoremediation of arsenic-contaminated soils in areas where P. vittata cannot grow.

  11. Absorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pteris vittata L.)

    Energy Technology Data Exchange (ETDEWEB)

    Bondada, Bhaskar R.; Tu, Shuxin; Ma, Lena Q

    2004-10-01

    The fact that heavy metals can enter various domains of the plant system through foliar pathways spurred us to explore if the fronds of the Chinese brake fern (Pteris vittata L.), a hyperaccumulator of arsenic, a carcinogenic metalloid, was proficient in absorbing arsenic in the form of sprays. The specific objective of this study was to investigate the impact of frond age, form of arsenic, and time of application on the absorption of foliar-applied arsenic by the brake fern; also examined were the effects of foliar sprays on surface ultrastructure and arsenic speciation in the frond following absorption. Foliar sprays of different arsenic concentrations (0, 50, 100, 200, and 400 ppm) were applied to young and fertile fronds. A positive linear relationship existed between arsenic concentration and absorption; the arsenic concentration of fronds increased from 50 to 200 ppm. Time-course analysis with excised pinnae indicated an initial linear increase followed by a plateau at 48 h. The young fronds with immature sori absorbed more arsenic (3100 ppm) than the fertile mature fronds (890 ppm). In the frond, the arsenic absorption was greatest in the lamina of the pinnae followed by the sori and the rachis. Applying arsenic during night (20:00-22:00 h) or afternoon (12:00-14:00 h) resulted in greater absorption of arsenic than the application in the morning (08:00-10:00 h). The arsenic absorption was greater through abaxial surfaces than through adaxial surfaces. The brake fern absorbed more arsenic when it was applied in the form of arsenite. Regardless of the form of arsenic and the surface it was applied to, arsenic occurred as arsenite, the reduced and the most toxic form of arsenic, after having been absorbed by the fronds. Scanning electron microscopy revealed no surface morphological alterations following all arsenic sprays. The study unequivocally illustrated that the Chinese brake fern absorbed foliar-applied arsenic with great efficiency. Consequently, the

  12. Allelopathy is involved in the formation of pure colonies of the fern Gleichenia japonica.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Saito, Yoshihumi; Ohno, Osamu; Suenaga, Kiyotake

    2013-04-15

    The fern Gleichenia japonica is one of the most widely distributed fern and occurs throughout East to South Asia. The species often dominates plant communities by forming large monospecific colonies. However, the potential mechanism for this domination has not yet been described. The objective of this study was to test the hypothesis that allelochemicals are involved in the formation of G. japonica colonies. An aqueous methanol extract of G. japonica inhibited the growth of seedlings of garden cress (Lepidium sativum), lettuce (Lactuca sativa), ryegrass (Lolium multiflorum) and timothy (Phleum pratense). Increasing extract concentration increased the inhibition. These results suggest that G. japonica contain allelopathic substances. The extract was then purified by several chromatographies with monitoring the inhibitory activity and two growth inhibitory substances causing the allelopathic effect were isolated. The chemical structures of the two substances were determined by spectral data to be a novel compound 3-O-β-allopyranosyl-13-O-β-fucopyranosyl-3β-hydroxymanool (1) and 18-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-13-epitorreferol (2). These compounds inhibited the shoot and root growth of garden cress, lettuce, alfalfa (Medicago sativa), timothy, ryegrass and barnyardgrass (Echinochloa crus-galli) at concentrations greater than 0.1-1.0mM. The concentrations required for 50% growth inhibition of root and shoot growth of these test plants ranged from 0.72 to 3.49mM and 0.79 to 3.51mM for compounds 1 and 2, respectively. Concentration of compounds 1 and 2 in soil under the pure colony of G. japonica was 4.9 and 5.7mM, respectively, indicating concentrations over those required for 50% growth inhibition are potentially available under monocultural stands of these ferns. Therefore, these compounds may contribute to the allelopathic effects caused by presence of G. japonica and may thus contribute to the establishment of monocultural stands by this

  13. [A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica].

    Science.gov (United States)

    Rojas Alvarado, Alexander Fco; Palacios Ríos, Mónica

    2006-09-01

    The new fern species Pteris herrerae A. Rojas & M. Palacios, endemic to Costa Rica, is described. It differs from P. decurrens C. Presl in basal segments reduced to 1/5-1/2 of the next segment (vs. 2/3-3/4), basal pinnae not bifurcated (vs. bifurcated), pinnae apex mucronate (vs. acuminate) and segment apex undulate (vs. dentate). It differs from Pteris consanguinea in the elliptic pinnae (vs. oblong), two segments reduced on the base (vs. lack), segments entire to undulate (vs. dentate), basal pinnae without basiscopic lobes (vs. with basiscopic lobes) and segment apex entire to undulate (vs. dentate).

  14. 2016 Award for Distinguished Contributions to the International Advancement of Psychology: Héctor Fernández-Álvarez.

    Science.gov (United States)

    2016-11-01

    The Award for Distinguished Contributions to the International Advancement of Psychology is given to individuals who have made sustained and enduring contributions to international cooperation and the advancement of knowledge in psychology. The 2016 award winner is Héctor Fernández-Álvarez, who "has woven a sophisticated network of international cooperation in psychotherapy research, training, and service provision throughout Latin America, Europe, and the United States." He was selected for his outstanding, innovative contributions to psychotherapy integration, clinical supervision, and the personal style of the therapist. Dr. Fernández-Álvarez's award citation, biography, and a selected bibliography are presented here. (PsycINFO Database Record

  15. El blocao (y el bloqueo de José Díaz Fernández

    Directory of Open Access Journals (Sweden)

    Luis Fernando Bueno Morillas

    2015-06-01

    Full Text Available El blocao (1928 fue la primera novela de José Díaz Fernández. Supuso un éxito editorial insólito hasta entonces porque reunía tres características novedosas: una actitud crítica ante la guerra de Marruecos, una integración de las novedades vanguardistas en la que su autor llamó literatura de avanzada y un posicionamiento del intelectual al lado de las reivindicaciones del pueblo. Sin embargo, aunque publicó otra novela un año después (La Venus mecánica, un libro teórico en el que definía la literatura que él propugnaba y practicaba (El nuevo romanticismo y algunas narraciones breves, Díaz Fernández se bloqueó y dejó la literatura narrativa que tan buenas expectativas levantó. Analizaremos las posibles causas de ese bloqueo.

  16. Polyphyly of the fern family Tectariaceae sensu Ching: Insights from cpDNA sequence data

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Tectariaceae are a pantropical fern family of about 20 genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL and atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria and Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with and should be included within the newly-defined Dryopteridaceae, and Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix, and Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae and to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.

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

    Science.gov (United States)

    Shao, Yizhen; Wei, Ran; Zhang, Xianchun; Xiang, Qiaoping

    2015-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Yizhen Shao

    Full Text Available 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.

  19. Polyphyly of the fern family Tectariaceae sensu Ching: insights from cpDNA sequence data.

    Science.gov (United States)

    Liu, HongMei; Zhang, XianChun; Chen, ZhiDuan; Dong, ShiYong; Qiu, YinLong

    2007-12-01

    Tectariaceae are a pantropical fern family of about 20 genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL and atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria and Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with and should be included within the newly-defined Dryopteridaceae, and Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix, and Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae and to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.

  20. Fertile structures with in situ spores of a dipterid fern from the Triassic in southern China.

    Science.gov (United States)

    Wang, Yongdong; Li, Liqin; Guignard, Gaëtan; Dilcher, David L; Xie, Xiaoping; Tian, Ning; Zhou, Ning; Wang, Yan

    2015-05-01

    Clathropteris was a typical dipterid fern with well documented fossil record and was widely dispersed during the Mesozoic; however, our knowledge of fertile structures including in situ spores for this genus is still very limited. Here we report well-preserved compression specimens of Clathropteris obovata Oishi from the Late Triassic of Guangyuan, Sichuan Province, China. The specimens show round to oval and exindusiate sori, vertical to oblique annuli in sporangia, and in situ trilete spores with verrucate and baculate sculptures, which are comparable to dispersed spore genera of Converrucosisporites and Conbaculatisporites. Comparisons of relevant fossil taxa suggest that specimens of C. obovata from Triassic of China provide for the first time in Asia the detailed fertile structures with in situ spore characters of dipterid fossil Clathropteris. Unlike living Dipteris, Mesozoic fossils of Dipteridaceae show a high diversity and a range of complex morphology of in situ spores, thus are significant for the evolutionary links between Dipteridaceae and other related fern clade, including Gleicheniaceae and Matoniaceae of the Gleicheniales.

  1. Intramolecular co-action of two independent photosensory modules in the fern phytochrome 3.

    Science.gov (United States)

    Kanegae, Takeshi

    2015-01-01

    Fern phytochrome3/neochrome1 (phy3/neo1) is a chimeric photoreceptor composed of a phytochrome-chromophore binding domain and an almost full-length phototropin. phy3 thus contains two different light-sensing modules; a red/far-red light receptor phytochrome and a blue light receptor phototropin. phy3 induces both red light- and blue light-dependent phototropism in phototropin-deficient Arabidopsis thaliana (phot1 phot2) seedlings. The red-light response is dependent on the phytochrome module of phy3, and the blue-light response is dependent on the phototropin module. We recently showed that both the phototropin-sensing module and the phytochrome-sensing module mediate the blue light-dependent phototropic response. Particularly under low-light conditions, these two light-sensing modules cooperate to induce the blue light-dependent phototropic response. This intramolecular co-action of two independent light-sensing modules in phy3 enhances light sensitivity, and perhaps allowed ferns to adapt to the low-light canopy conditions present in angiosperm forests.

  2. Nutrient values and bioactivities of the extracts from three fern species in China: a comparative assessment.

    Science.gov (United States)

    Qi, Guoyuan; Yang, Liuqing; Xiao, Chunxia; Shi, Jing; Mi, Yashi; Liu, Xuebo

    2015-09-01

    Pteridium aquilinum, Osmunda cinnamomea Linn, and Athyrium multidentatum (Doll.) Ching are three fern species widely consumed as potherbs and traditional medicinal herbs in China. Nevertheless, no detailed comparative assessments of their nutrient values and bioactivities have been reported. In this paper, we examined the nutrient content of these ferns and the bioactivities of their extracts with a comparative method. The results indicated that they were nutrient dense for proteins, carbohydrates, fat and minerals. Compared with Pteridium aquilinum and Osmunda cinnamomea Linn, the extract from Athyrium multidentatum (Doll.) Ching was found to possess the strongest antioxidant activity, protective effects on biomolecules, cellular antioxidant activity, and antiproliferative effects owing to its highest total phenolic (476.52 ± 11.26 mg GAE per g extract) and total flavonoid (924.81 ± 4.25 mg RNE per g extract) contents. Further, Athyrium multidentatum (Doll.) Ching can lead to caspase-3 activation, poly ADP-ribose polymerase cleavage, mitochondrial membrane potential (MMP) reduction and inhibition of wound-healing in a dose-dependent manner in HepG2 cells. These results demonstrate the remarkable potential of Pteridium aquilinum, Osmunda cinnamomea Linn, and Athyrium multidentatum (Doll.) Ching as valuable sources of nutrients and natural antioxidants, and among which Athyrium multidentatum (Doll.) Ching has potential anticancer properties.

  3. Human Detection Using Random Color Similarity Feature and Random Ferns Classifier.

    Science.gov (United States)

    Zhang, Miaohui; Xin, Ming

    2016-01-01

    We explore a novel approach for human detection based on random color similarity feature (RCS) and random ferns classifier which is also known as semi-naive Bayesian classifier. In contrast to other existing features employed by human detection, color-based features are rarely used in vision-based human detection because of large intra-class variations. In this paper, we propose a novel color-based feature, RCS feature, which is yielded by simple color similarity computation between image cells randomly picked in still images, and can effectively characterize human appearances. In addition, a histogram of oriented gradient based local binary feature (HOG-LBF) is also introduced to enrich the human descriptor set. Furthermore, random ferns classifier is used in the proposed approach because of its faster speed in training and testing than traditional classifiers such as Support Vector Machine (SVM) classifier, without a loss in performance. Finally, the proposed method is conducted in public datasets and achieves competitive detection results.

  4. Leaf micromorphology of four medicinal ferns species in Tasik Chini, Pahang

    Science.gov (United States)

    Nurnida, M. K.; Noraini, T.; Ruzi, A. R.; Idris, S.

    2015-09-01

    A leaf micromorphology study was conducted on four selected medicinal ferns species in Tasik Chini, Pahang. The four chosen species were Adiantum latifolium Lam., Lygodium flexuosum (L.) Sw., Lygodium microphyllum (Cav.) R. Br. and Tectaria singaporeana (Wall.) Ching. The objective of this study is to identify the leaf micromorphological characteristics that can be used as supportive scientific data especially in authentification of medicinal ferns species. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Results in this study have shown some similarities and variations in the leaf micromorphological characteristics such as presence of cuticular striation, type of epicuticular waxes, structural feature of stomata and also in the presence or absence and type of trichomes. Four types of epicuticular waxes and only one type of trichome were observed, that were specific for some species. As a conclusion, the results of this study definitely proven that leaf micromorphology can be used for species authentification and might useful as preliminary scientific data for future references and further study.

  5. Modelling phytoremediation by the hyperaccumulating fern, Pteris vittata, of soils historically contaminated with arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Shelmerdine, Paula A.; Black, Colin R. [School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD (United Kingdom); McGrath, Steve P. [Rothamsted Research, Harpenden, Herts AL5 2JQ (United Kingdom); Young, Scott D., E-mail: scott.young@nottingham.ac.u [School of Biosciences, Biology Building, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2009-05-15

    Pteris vittata plants were grown on twenty-one UK soils contaminated with arsenic (As) from a wide range of natural and anthropogenic sources. Arsenic concentration was measured in fern fronds, soil and soil pore water collected with Rhizon samplers. Isotopically exchangeable soil arsenate was determined by equilibration with {sup 73}As{sup V}. Removal of As from the 21 soils by three sequential crops of P. vittata ranged between 0.1 and 13% of total soil As. Ferns grown on a soil subjected to long-term sewage sludge application showed reduced uptake of As because of high available phosphate concentrations. A combined solubility-uptake model was parameterised to enable prediction of phytoremediation success from estimates of soil As, 'As-lability' and soil pH. The model was used to demonstrate the remediation potential of P. vittata under different soil conditions and with contrasting assumptions regarding re-supply of the labile As pool from unavailable forms. - This paper presents a predictive model for phytoremediation of soils, historically contaminated with arsenic, by the hyperaccumulator P. vittata.

  6. Arsenic-induced morphogenic response in roots of arsenic hyperaccumulator fern Pteris vittata.

    Science.gov (United States)

    Forino, Laura Maria Costantina; Ruffini Castiglione, Monica; Bartoli, Giacomo; Balestri, Mirko; Andreucci, Andrea; Tagliasacchi, Anna Maria

    2012-10-15

    On the assumption that arsenic induces stress morphogenetic responses involved in As tolerance and hyperaccumulation in the Pteris vittata fern, we analyzed the root system of young sporophytes grown in 250, 334, and 500 μM As for five days and for 14 days. Anatomical and histological analyses were performed in plants grown for five days to evaluate the number, position, length and differentiation pattern of root hairs. AgNOR staining, employed to study nucleolus behavior in root apices, showed that arsenic influences nucleolar activity (evaluated by nucleolus size, number and absorbance) in the root meristem. In plants treated with 250 and 334 μM As an acropetal shift of root hair development and an increase in hair length and density were observed, linked to an ectopic pattern of differentiation. The opposite trend was recorded in plants treated with 500 μM As. It is worth noting the presence of living border-like cells, not yet observed in ferns, and their increase following As treatments. Analysis and vitality of border-like cells were surveyed after 14 days of treatments. In conclusion As treatments elicited a stress-induced morphogenic response which, by modifying the differentiation pattern, number and length of root hairs, modulating nucleolar activity and interacting with the rhizosphere by inducing border-like cell production, may adjust the rate of root uptake and its metabolic activity.

  7. Effect of soil pH on as hyperaccumulation capacity in fern species, Pityrogramma calomelanos.

    Science.gov (United States)

    Anh, B T Kim; Kim, D D; Kuschk, P; Tua, T V; Hue, N T; Minh, N N

    2013-03-01

    Arsenic uptake by hyperaccumulator plant species depends on many different environmental factors. Soil pH is one of the most important factors due to its combined effect on both chemical and biological processes. In greenhouse experiment, the effect of pH (within the pH range 3.6 - 8.9) on As uptake as well as biomass of Pityrogramma calomelanos was evaluated. The plants were grown in mining soil containing 645.6 mg As kg(-1) for 14 weeks. Within this time, the plant biomass growth was 3.78 - 8.64 g d. wt. per plant and the removal amounted 6.3-18.4 mg As per plant. Translocation factor (ratio of As in fronds to roots) of the fern was 3.6 - 9.7, indicating its potential in phytoremediation of As contaminated soil. Influence of pH on As bioavailability was visible as the available As concentration was higher in acidic soil compared to alkaline soil. Furthermore, it was found that As accumulation by Pityrogramma calomelanos was optimum in the soil of pH 3.6. Nevertheless, the results of this study demonstrate that remediation of As-contaminated mining soils, by this fern, can be improved by changing the soil pH from 4.6 to 6.8.

  8. Arbuscular mycorrhizae increase the arsenic translocation factor in the As hyperaccumulating fern Pteris vittata L.

    Science.gov (United States)

    Trotta, A; Falaschi, P; Cornara, L; Minganti, V; Fusconi, A; Drava, G; Berta, G

    2006-09-01

    Phytoremediation techniques are receiving more attention as decontaminating strategies. Phytoextraction makes use of plants to transfer contaminants from soil to the aboveground biomass. This research is devoted to study the effects of arbuscular mycorrhizae (AM) on growth and As hyperaccumulation in the Chinese brake fern Pteris vittata. We grew for 45 days P. vittata sporophytes, infected or not infected with the AM fungi Glomus mosseae or Gigaspora margarita, in a hydroponic system on quartz sand. As-treated plants were weekly fed with 25 ppm As. The As treatment produced a dramatic increase of As concentration in pinnae and a much lower increase in roots of both mycorrhizal and control plants. Mycorrhization increased pinnae dry weight (DW) (G. margarita = G. mosseae) and leaf area (G. margarita > G. mosseae), strongly reduced root As concentration (G. mosseae > G. margarita), and increased the As translocation factor (G. mosseae > G. margarita). The concentration of phosphorus in pinnae and roots was enhanced by both fungi (G. margarita > G. mosseae). The quantitatively different effects of the two AM fungi on plant growth as well as on As and P distribution in the fern suggest that the As hyperaccumulation in P. vittata can be optimized by a careful choice of the symbiont.

  9. Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

    Science.gov (United States)

    López-Sepúlveda, Patricio; Takayama, Koji; Greimler, Josef; Crawford, Daniel J; Peñailillo, Patricio; Baeza, Marcelo; Ruiz, Eduardo; Kohl, Gudrun; Tremetsberger, Karin; Gatica, Alejandro; Letelier, Luis; Novoa, Patricio; Novak, Johannes; Stuessy, Tod F

    2015-01-01

    A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

  10. Leaf micromorphology of four medicinal ferns species in Tasik Chini, Pahang

    Energy Technology Data Exchange (ETDEWEB)

    Nurnida, M. K., E-mail: nurnidakamal@gmail.com; Noraini, T.; Ruzi, A. R.; Idris, S. [School of Environmental and Natural Resource Sciences Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    A leaf micromorphology study was conducted on four selected medicinal ferns species in Tasik Chini, Pahang. The four chosen species were Adiantum latifolium Lam., Lygodium flexuosum (L.) Sw., Lygodium microphyllum (Cav.) R. Br. and Tectaria singaporeana (Wall.) Ching. The objective of this study is to identify the leaf micromorphological characteristics that can be used as supportive scientific data especially in authentification of medicinal ferns species. The procedures involved such as dehydration, critical point drying, gold coated and examination under scanning electron microscope. Results in this study have shown some similarities and variations in the leaf micromorphological characteristics such as presence of cuticular striation, type of epicuticular waxes, structural feature of stomata and also in the presence or absence and type of trichomes. Four types of epicuticular waxes and only one type of trichome were observed, that were specific for some species. As a conclusion, the results of this study definitely proven that leaf micromorphology can be used for species authentification and might useful as preliminary scientific data for future references and further study.

  11. A gene encoding a vicilin-like protein is specifically expressed in fern spores. Evolutionary pathway of seed storage globulins.

    Science.gov (United States)

    Shutov, A D; Braun, H; Chesnokov, Y V; Bäumlein, H

    1998-02-15

    The isolation and characterisation of a cDNA coding for a vicilin-like protein of the fern Matteuccia struthiopteris is described. The corresponding gene is specifically expressed during late stages of spore development. Extensive sequence comparisons suggest that the fern protein can be considered as a molecular missing link between single-domain germin/spherulin-like proteins and two-domain seed storage globulins of gymnosperms and angiosperms. Further, evidence is provided for the existence of a superfamily of structurally related, functionally different proteins which includes storage globulins of the vicilin and legumin families, a membrane-associated sucrose-binding protein of soybean, a Forssman antigen-binding lectin of velvet bean, the precursor of the vacuolar membrane bound proteins MP27/MP32 of pumpkin, the embryogenesis-specific protein Gea8 of carrot, the fern-spore-specific protein described here as well as the functionally diverse family of germins/germin-like proteins and the spherulins of myxomycetes. We propose that seed storage globulins of spermatophytes evolved from desiccation-related single-domain proteins of prokaryotes via a duplicated two-domain ancestor that is best represented by the extant fern spore-specific vicilin-like protein.

  12. Chemical Composition of Soil Horizons and Aggregate Size Fractions Under the Hawaiian Fern Dicranopteris and Angiosperm Cheirodendrom

    Science.gov (United States)

    Stewart, C. E.; Amatangelo, K.; Neff, J.

    2007-12-01

    Soil organic matter (SOM) inherits much of its chemical nature from the dominant vegetation, including phenolic (lignin-derived), aromatic, and aliphatic (cutin and wax-derived) compounds. However, relatively stable recalcitrant compounds may also be formed as a result of condensation and complexation reactions through decomposition and protected with association with mineral particles. The Hawaiian fern species Dicranopteris decomposes more slowly than the angiosperm, Cheirodendrom due to high concentrations of recalcitrant C compounds. These aliphatic fern leaf waxes are well-preserved and may comprise a large portion of the recalcitrant organic matter in these soils. Our objective was to determine the chemical composition of the SOM under the O- (litter-dominated) and the A- (mineral) horizons formed under fern and angiosperm vegetation. To determine the effect of mineral-association, we fractioned the soil into four size classes; 850-590 μm, 590-180 μm, 180-53 μm and cutin and leaf waxes (alkene and alkanes structures) occurred in the 180-53 μm fraction, which has been shown to be the most stable of the aggregate-size fractions. Soils developed under fern versus angiosperm vegetation have distinct chemical signatures, which likely determine the recalcitrance of the SOM.

  13. Alpha-expansins in the semiaquatic ferns Marsilea quadrifolia and Regnellidium diphyllum: evolutionary aspects and physiological role in rachis elongation.

    Science.gov (United States)

    Kim, J H; Cho, H T; Kende, H

    2000-12-01

    To investigate the evolutionary history of expansins and their role in cell elongation in early land plants, we isolated two alpha-expansin genes, Mq-EXP1 and Rd-EXP1, respectively, from the semiaquatic ferns Marsilea quacdrifolia L. and Regnellidium diphyllum Lindm. The deduced amino acid sequences of the fern expansins exhibit a high degree of identity to those of seed plants, showing that expansin genes were conserved during the evolution of vascular plants. Gel-blot analysis of M. quadrifolia and R. diphyllum genomic DNA indicated that, in both ferns, alpha-expansins are encoded by multigene families. Expression of alpha-expansin genes probed with Mq-EXP1 was confined to the elongating region of the Marsilea rachis. Cell-wall proteins of M. quadrifolia induced in-vitro extension of acidified cucumber cell walls. In R. diphyllum, expression of Rd-EXP1 increased when elongation of the rachis was enhanced by submergence or ethylene. These results indicate that alpha-expansins act as wall-loosening proteins in ferns, as has been proposed for angiosperms. In addition, Rd-EXP1 may play a role in mediating elongation of the rachis in submerged plants.

  14. Antibacterial activity of the terrestrial fern Lygodium flexuosum (L. Sw. against multidrug resistant enteric- and uro-pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Nabakishore Nayak

    2013-01-01

    Conclusions: Phytochemical analysis of the water-extract of L. flexuosum confirmed the presence of glycosides and carbohydrates, but alkaloids, terpenoids, steroids, saponins, tannins, and flavonoids were absent. L. flexuosum, being a fern, is a suitable non-microbial source of antimicrobial for MDR strains of major enteric and uro-pathogens.

  15. Biodiversity and spatial distribution of epiphytic ferns on Alsophila setosa Kaulf. (Cyatheaceae caudices in Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    JL. Schmitt

    Full Text Available The extractive exploitation of the tree fern Alsophila setosa Kaulf. alters forest formations and diminishes the availability of micro-habitat for epiphytes. A survey of epiphytic fern communities on A. setosa at 16 study sites in different forest formations in the State of Rio Grande do Sul, Brazil, documented the occurrence of 31 species representing 16 genera and six families. The greatest richness of species occurred in Polypodiaceae (39% and in the genus Asplenium L. (22%. Habitual holoepiphyte was the predominant ecological category, representing 61% of the species. Similarity analysis demonstrated heterogeneity in the composition of the epiphytic ferns at the study sites and indicated that the vegetation type is not the main factor for floristic difference. The lowest total specific richness (5 was recorded for the seasonal deciduous forest site. The majority of the sites presented similar averages of phorophyte height and epiphyte richness per caudex. In 25% of the sites the height of the host plants presented significant correlation with specific richness. Considering that the majority of the epiphytes are habitual and that some of them occur exclusively or preferentially on tree ferns, the maintenance of these host plants in the vegetation is essential for the conservation of epiphytic species.

  16. Epiphytic ferns in swamp forest remnants of the coastal plain of southern Brazil: latitudinal effects on the plant community

    Directory of Open Access Journals (Sweden)

    Letícia S. Machado

    Full Text Available ABSTRACT Community structure and spatial distribution of epiphytic ferns in swamp forest remnants along the coastal plain of the state of Rio Grande do Sul were analyzed. A total of 440 trees were sampled in fifty-seven 10 x 10 m plots. Each phorophyte was divided into five ecological zones (strata, where all species of epiphytic ferns were recorded. A total of 34 species representing 18 genera in six families were recorded. Polypodiaceae was the most represented family with 17 species, and Microgramma vacciniifolia had the highest epiphytic importance value. Characteristic holoepiphyte was the predominant ecological category, representing 70 % of the species. Ordination analysis showed a gradual change in floristic composition between ecological zones with richness differing significantly between strata. We observed that with increasing latitude there was a decrease in mean temperature and total rainfall, but an increase in frosts. These climatic and phytogeography changes result in a reduction in species richness and a change in the structure of epiphytic fern communities in a north-to-south direction. The importance of swamp forest remnants of the coastal plain to the diversity of epiphytic ferns is discussed.

  17. The freshwater fern Azolla (Azollaceae) from Eocene Arctic and Nordic Sea sediments: New species and their stratigraphic distribution

    NARCIS (Netherlands)

    van der Burgh, J.; Collinson, M.E.; van Konijnenburg-van Cittert, J.H.A.; Barke, J.; Brinkhuis, H.

    2013-01-01

    Three new species of the freshwater fern Azolla are described from Eocene marine deposits of the Arctic and Nordic seas, bringing the total number of species now documented from these areas to five. Azolla arctica Collinson et al., Azolla jutlandica Collinson et al., Azolla nova sp. nov. and Azolla

  18. Macrobenthos of Vembanad estuary in relation to the deposition of degraded water fern Salvinia and other macrophytes

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.; Meenakshikunjamma, P.P.; Vengayil, D.T.

    Composition and seasonal abundance of macrobenthos in Vembanad estuary (India) seems to be influenced by the density of decaying macrophytes, especially the water fern Salvinia , deposited at the bottom of the estuary at the rate of 356.76 g/m super...

  19. Host range and genetic relatedness of Colletotrichum acutatum isolates from fruit crops and leatherleaf fern in Florida.

    Science.gov (United States)

    MacKenzie, S J; Peres, N A; Barquero, M P; Arauz, L F; Timmer, L W

    2009-05-01

    Isolates of Colletotrichum acutatum were collected from anthracnose-affected strawberry, leatherleaf fern, and Key lime; ripe-rot-affected blueberry; and postbloom fruit drop (PFD)-affected sweet orange in Florida. Additional isolates from ripe-rot-affected blueberry were collected from Georgia and North Carolina and from anthracnose-affected leatherleaf fern in Costa Rica. Pathogenicity tests on blueberry and strawberry fruit; foliage of Key lime, leatherleaf fern, and strawberry; and citrus flowers showed that isolates were highly pathogenic to their host of origin. Isolates were not pathogenic on foliage of heterologous hosts; however, several nonhomologous isolates were mildly or moderately pathogenic to citrus flowers and blueberry isolates were pathogenic to strawberry fruit. Based on sequence data from the internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region of the rDNA repeat, the glutaraldehyde-3-phosphate dehydrogenase intron 2 (G3PD), and the glutamine synthase intron 2 (GS), isolates from the same host were identical or very similar to each other and distinct from those isolated from other hosts. Isolates from leatherleaf fern in Florida were the only exception. Among these isolates, there were two distinct G3PD and GS sequences that occurred in three of four possible combinations. Only one of these combinations occurred in Costa Rica. Although maximum parsimony trees constructed from genomic regions individually displayed little or no homoplasy, there was a lack of concordance among genealogies that was consistent with a history of recombination. This lack of concordance was particularly evident within a clade containing PFD, Key lime, and leatherleaf fern isolates. Overall, the data indicated that it is unlikely that a pathogenic strain from one of the hosts examined would move to another of these hosts and produce an epidemic.

  20. FERNS ON MAOERSHAN MOUNTAINDISTRICT IN HEILONGJIANG PROVINCE%黑龙江省帽儿山地区的蕨类植物

    Institute of Scientific and Technical Information of China (English)

    曹建国; 王雪艳; 戴绍军

    2000-01-01

    In this paper the classification and the key to the ferns on Maoershan Mountain district have been done. More than 40 species of ferns are listed, and the relation between the different ferns and their environmental factors are also discussed.%本文对帽儿山地区的蕨类植物进行了分类检索,记述了帽儿山地区蕨类植物40余种,并阐明它们的分布与环境因子的关系.

  1. Microsite-limited recruitment controls fern colonization of post-agricultural forests.

    Science.gov (United States)

    Flinn, Kathryn M

    2007-12-01

    Assessing the relative roles of dispersal limitation and environmental effects in population dynamics and community assembly is fundamental to understanding patterns of species distribution and diversity. In forests growing on abandoned agricultural lands, both legacies of vegetation disturbance and changes in the abiotic environment shape the diversity and composition of recovering communities. Here I specify how interactions among historical, environmental, and biological factors influence species distributions, focusing on three fern species with contrasting distributions across forests of different history in central New York, USA: Dryopteris carthusiana, Dryopteris intermedia, and Polystichum acrostichoides. Using population surveys, spore-trap and spore-bank studies, and a three-year field experiment, I compare demographic rates among species and between forest types to determine which life history stages limit colonization and which traits explain species distributions. Adult plants of all three species were larger and more likely to produce spores in post-agricultural forests than in adjacent, uncleared stands. Though lower population densities led to fewer spores in post-agricultural soils, spore availability still exceeded recruitment by four to five orders of magnitude. Sowing additional spores had relatively little effect, while microhabitat conditions had the greatest impact on establishment rates. Given similar microsites, the two forest types had equal rates of establishment, but some forest-floor features preferentially occupied by juvenile plants were less frequent in post-agricultural stands. The availability of suitable sites for establishment, created by small-scale heterogeneity on forest floors, thus limits both the growth of fern populations and the colonization of new habitats. In fact, reduced microtopographic variation in post-agricultural forests may represent a greater hindrance to plant establishment than changes in mean environmental

  2. Macedonio Fernández o el primer mentiroso del Río de la Plata

    Directory of Open Access Journals (Sweden)

    Diego Vecchio

    2006-07-01

    Full Text Available 1- Lingüística y cartografíaComo corresponde a un “filósofo” idealista, Macedonio Fernández también fue un lingüista. En 1928, en No toda es vigilia, en el capítulo intitulado “Definiciones de ideas y vocablos”, elabora una primera teoría del lenguaje :La palabra es un signo para comunicación. Esta es sólo, más que comunicación, suscitación de imagen por signo. Y el orden de lo así comunicable es puramente el de las imágenes, aunque haciendo nacer en otra mente las imágenes que tenemos ahora ...

  3. Conocer el Nuevo Mundo: referencialidad en las ilustraciones de Fernández de Oviedo

    Directory of Open Access Journals (Sweden)

    Vanina M. Teglia

    2014-12-01

    Full Text Available The illustrations drawn by the official chronicler of the Indies, Gonzalo Fernández de Oviedo, to accompany his sections on American flora were the first of this type to appear on a printed edition. Between the paradigms of medieval bookish hermeneutics and the growing appreciation for the witness testimony, the Veedor del Oro in the New World, writer and illustrator employs visual language devices to offer reliable proof of the nature he observed and, simultaneously, apprehend it through the imperial discourse’s forms of discernment. In this paper, we will analyze the images that Oviedo merged into his manuscripts and printed editions to show several amazingly significant references concentrated in them: references to American reality, by means of mimesis and similitude; references to the familiar schemes of Western pictorial traditions, and, finally, to Christian imperial hierarchies. This whole referential complex is finally put to the service of imperial expansion

  4. El tratado de estadística de Fernández-Baños

    OpenAIRE

    Arenzana, Víctor

    1997-01-01

    El Tratado de Estadística de Olegario Fernández Baños fue el primer libro de Estadística Matemática en sentido moderno que se publicó en España. Anteriormente, se habían publicado libros de estadística para la asignatura de geógrafa y estadística industrial y Mercantil de las Escuelas de Comercio y para la de Economía Política de las Facultades de Derecho. tos libros de texto para esas asignaturas trataban, generalmente, temas de carácter administrativa, descripción de los métodos estadístic...

  5. Colombia en cuatro tiempos : Carmelo Fernández 1809-1887

    OpenAIRE

    1991-01-01

    San José de Guama (estado de Yaracuy, Venezuela), 30 de junio de 1809 - Caracas, 9 de febrero de 1887. En 1983 a los 96 años de su muerte y dentro de las conmemoraciones de los 200 años del nacimiento de Simón Bolívar, fueron trasladados los restos del artista y militar Carmelo Fernández al Panteón Nacional de Caracas, donde reposan cercanos a los del Libertador Cuando se observa la baldosa del piso que a manera de tumba presenta su nombre, se recuerda su fidelidad y admiración por Bolívar. N...

  6. Arsenic speciation for the phytoremediation by the Chinese brake fern, Pteris vittata

    Institute of Scientific and Technical Information of China (English)

    R. Shoji; R. Yajima; Y. Yano

    2008-01-01

    Arsenic (As) speciation for the phytoremediation by the Chinese brake fern was studied. In particular, the mechanism of how plants induce compounds containing thiol (SH) and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined. Pteris vittata callus could efficiently reduce As(V) to As(Ill) by the rapid introduction of reductase and synthesize thiols leading to phytoehelatins production. Furthermore, Pteris vittata could control phosphate concentration in the cells corresponding to the concentration of arsenite and arsenate. To our best knowledge, this is the first report to show the mechanisms of such high As tolerance of Pteris vittata using their callus in terms of in vitro approach for the analysis of As speciation and metabolism route.

  7. Colombia en cuatro tiempos : Carmelo Fernández 1809-1887

    Directory of Open Access Journals (Sweden)

    Beatriz González

    1991-09-01

    Full Text Available San José de Guama (estado de Yaracuy, Venezuela, 30 de junio de 1809 - Caracas, 9 de febrero de 1887. En 1983 a los 96 años de su muerte y dentro de las conmemoraciones de los 200 años del nacimiento de Simón Bolívar, fueron trasladados los restos del artista y militar Carmelo Fernández al Panteón Nacional de Caracas, donde reposan cercanos a los del Libertador Cuando se observa la baldosa del piso que a manera de tumba presenta su nombre, se recuerda su fidelidad y admiración por Bolívar. Nunca debió de pasar por la mente de este hombre humilde y singular que sus restos descansarían en tan notable sitio de veneración y culto.

  8. Arsenic speciation for the phytoremediation by the Chinese brake fern, Pteris vittata.

    Science.gov (United States)

    Shoji, R; Yajima, R; Yano, Y

    2008-01-01

    Arsenic (As) speciation for the phytoremediation by the Chinese brake fern was studied. In particular, the mechanism of how plants induce compounds containing thiol (SH) and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined. Pteris vittata callus could efficiently reduce As(V) to As(III) by the rapid introduction of reductase and synthesize thiols leading to phytochelatins production. Furthermore, Pteris vittata could control phosphate concentration in the cells corresponding to the concentration of arsenite and arsenate. To our best knowledge, this is the first report to show the mechanisms of such high As tolerance of Pteris vittata using their callus in terms of in vitro approach for the analysis of As speciation and metabolism route.

  9. Development and characterization of 27 microsatellite markers for the mangrove fern, Acrostichum aureum (Pteridaceae)1

    Science.gov (United States)

    Yamamoto, Takashi; Tsuda, Yoshiaki; Mori, Gustavo Maruyama; Cruz, Mariana Vargas; Shinmura, Yoshimi; Wee, Alison K. S.; Takayama, Koji; Asakawa, Takeshi; Yamakawa, Takeru; Suleiman, Monica; Núñez-Farfán, Juan; Webb, Edward L.; Watano, Yasuyuki; Kajita, Tadashi

    2016-01-01

    Premise of the study: Twenty-seven nuclear microsatellite markers were developed for the mangrove fern, Acrostichum aureum (Pteridaceae), to investigate the genetic structure and demographic history of the only pantropical mangrove plant. Methods and Results: Fifty-six A. aureum individuals from three populations were sampled and genotyped to characterize the 27 loci. The number of alleles and expected heterozygosity ranged from one to 15 and 0.000 to 0.893, respectively. Across the 26 polymorphic loci, the Malaysian population showed much higher levels of polymorphism compared to the other two populations in Guam and Brazil. Cross-amplification tests in the other two species from the genus determined that seven and six loci were amplifiable in A. danaeifolium and A. speciosum, respectively. Conclusions: The 26 polymorphic microsatellite markers will be useful for future studies investigating the genetic structure and demographic history of of A. aureum, which has the widest distributional range of all mangrove plants. PMID:27672519

  10. Ferns, mosses and liverworts as model systems for light-mediated chloroplast movements.

    Science.gov (United States)

    Suetsugu, Noriyuki; Higa, Takeshi; Wada, Masamitsu

    2016-11-17

    Light-induced chloroplast movement is found in most plant species, including algae and land plants. In land plants with multiple small chloroplasts, under weak light conditions, the chloroplasts move towards the light and accumulate on the periclinal cell walls to efficiently perceive light for photosynthesis (the accumulation response). Under strong light conditions, chloroplasts escape from light to avoid photodamage (the avoidance response). In most plant species, blue light induces chloroplast movement, and phototropin receptor kinases are the blue light receptors. Molecular mechanisms for photoreceptors, signal transduction and chloroplast motility systems are being studied using the model plant Arabidopsis thaliana. However, to further understand the molecular mechanisms and evolutionary history of chloroplast movement in green plants, analyses using other plant systems are required. Here, we review recent works on chloroplast movement in green algae, liverwort, mosses and ferns that provide new insights on chloroplast movement.

  11. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.

    2011-01-01

    The Greater Cape Floristic Region (GCFR) of southern Africa is characterised by large, endemic radiations of flowering plants, the so-called ‘Cape Clades’, but it is unknown whether such radiations are also found in non-angiosperms. We hypothesise that GCFR-endemic lineages exist in the xeric...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe...... of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  12. Casa Fernández Oks : Casa mirando el río

    OpenAIRE

    2000-01-01

    Esta casa fue el resultado de un pedido de la familia Fernández-Oks cuando su hija era aún una niña, por lo tanto, el programa es muy sencillo: estar, comedor, cocina, espacios exteriores preparados para los festejos familiares o con amigos, dos dormitorios y garage. Cuando la hija creció se agregó un tercer dormitorio para los visitantes. El desafío más importante del proyecto, lo planteó la ubicación del Río de La Plata y las vistas hacia él. Por lo tanto era casi una obligación abrir la ca...

  13. Dos cuentos de Fernández Guardia: "El estreno" y "La política"

    OpenAIRE

    2006-01-01

    En Fernández Guardia tenemos un autor mucho más complejo y menos homogéneo que sus contemporáneos, desde el punto de vista del género de sus obras y del estilo reacio a la clasificación y al análisis según los patrones tradicionales aplicables a los autores de su época. La importancia tanto en calidad como en cantidad de su obra de historiador, ha ocultado, inmerecidamente a nuestro juicio, el valor de su obra literaria.

  14. El desencuentro de la novela argentina: Macedonio Fernández y el texto nacional

    OpenAIRE

    Castellarnau, Ariadna

    2012-01-01

    Macedonio Fernández dedicó más de tres décadas a la escritura de una novela extraña, inclasificable y cuya terminación fue postergada a lo largo de sucesivos manuscritos. Museo de la novela de la Eterna se mantuvo inédito hasta su publicación póstuma en 1974. Casi toda la bibliografía macedoniana coincide en el análisis de Museo de la novela de la Eterna como la obra fundamental del autor y, a la vez, como uno de los textos más renovadores de la literatura latinoamericana. Macedonio de...

  15. Microstructural features of water fern Salvinia natans (L. All. organ surfaces

    Directory of Open Access Journals (Sweden)

    M.M. Shcherbatiuk

    2015-05-01

    Full Text Available The microstructure of the organs surface of the water fern Salvinia natans (L. All. has been studied under scanning electron microscope. It was established that the existence on the border between air and water environments is suported by specific microstructure of floating leaves. The adaxial side of floating leaves has well-developed cuticle and stomata placed below the level of epidermis, while abaxial surface of such leaves and submerged modified leaves are characterized by ultra-thin cell walls of the epidermis and numerous filamentous trichomes. We calculated number of stomata per unit area of leaves and the average diameter of stomata. It is claimed that the structure of wall of the sporocarp promotes the passage of the annual summer-green rhythm. Sporocarp provides diving of mega- and microsporangia to the bottom of the water reservoir in autumn and their raising on the water surface in the spring after destruction of its walls.

  16. La importancia de 1958 en la obra de Rafa Fernández

    Directory of Open Access Journals (Sweden)

    Mauricio Oviedo Salazar

    2015-05-01

    Full Text Available El ensayo trata la importancia que tuvo 1958 para la producción artística del costarricense Rafa Fernández. En dicho año el artista estudió en Nicaragua, bajo la dirección de Rodrigo Peñalba, en la Escuela Nacional de Bellas Artes de Managua. Este fue un periodo determinante en su carrera, ya que consigue herramientas pictóricas que serán empleadas en sus pinturas procedentes de la década de los sesenta, por ejemplo, el uso de disímiles texturas y el manejo de colores oscuros que le proporcionaban a sus cuadros una estética grotesca y violenta.

  17. Accelerated rate of molecular evolution for vittarioid ferns is strong and not driven by selection.

    Science.gov (United States)

    Rothfels, Carl J; Schuettpelz, Eric

    2014-01-01

    Molecular evolutionary rate heterogeneity-the violation of a molecular clock-is a prominent feature of many phylogenetic data sets. It has particular importance to systematists not only because of its biological implications, but also for its practical effects on our ability to infer and date evolutionary events. Here we show, using both maximum likelihood and Bayesian approaches, that a remarkably strong increase in substitution rate in the vittarioid ferns is consistent across the nuclear and plastid genomes. Contrary to some expectations, this rate increase is not due to selective forces acting at the protein level on our focal loci. The vittarioids bear no signature of the change in the relative strengths of selection and drift that one would expect if the rate increase was caused by altered post-mutation fixation rates. Instead, the substitution rate increase appears to stem from an elevated supply of mutations, perhaps limited to the vittarioid ancestral branch. This generalized rate increase is accompanied by extensive fine-scale heterogeneity in rates across loci, genomes, and taxa. Our analyses demonstrate the effectiveness and flexibility of trait-free investigations of rate heterogeneity within a model-selection framework, emphasize the importance of explicit tests for signatures of selection prior to invoking selection-related or demography-based explanations for patterns of rate variation, and illustrate some unexpected nuances in the behavior of relaxed clock methods for modeling rate heterogeneity, with implications for our ability to confidently date divergence events. In addition, our data provide strong support for the monophyly of Adiantum, and for the position of Calciphilopteris in the cheilanthoid ferns, two relationships for which convincing support was previously lacking.

  18. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil

    Science.gov (United States)

    Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant’s dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  19. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.

    Science.gov (United States)

    de Jesus Jatoba, Luciana; Varela, Rosa Maria; Molinillo, José Maria Gonzalez; Ud Din, Zia; Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant's dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  20. Mycorrhizal association in gametophytes and sporophytes of the fern Pteris vittata (Pteridaceae with Glomus intraradices

    Directory of Open Access Journals (Sweden)

    Alicia E Martinez

    2012-06-01

    Full Text Available Ferns, which are usually colonizing different environments and their roots frequently present mycorrhization, have two adult stages in their life cycle, the sporophytic and the gametophytic phase. This paper describes the experimental mycorrhizal association between Pteris vittata leptosporangiate fern and a strain of Glomus intraradices during the life cycle of the fern, from spore germination to the development of a mature sporophyte. The aim of this study was to compare the colonization pattern of in vitro cultures of G. intraradices along the fern life cycle with those found in nature. For this, mature spores were obtained from fertile P. vittata fronds growing in walls of Buenos Aires city, Argentina. Roots were stained and observed under the light microscope for arbuscular mycorrhizal colonization. Approximately, 75 fern spores were cultured in each pot filled with a sterile substrate and G. intraradices (BAFC N° 51.331 as inoculum on the surface. After germination took place, samples were taken every 15 days until the fern cycle was completed. In order to determine colonization dynamics each sample was observed under optical and confocal microscope after staining. Gametophyte was classified as Adiantum type. Male and female gametangia were limited to the lower face, mycorrhizal colonization started when they were differentiated and took place through the rhizoids. Spores and vesicles were not found in this cycle stage. Paris-type mycorrhizal colonization was established in the midrib and in the embrionary foot. It was colonized by external mycelium. When the first root was developed soil inoculum colonized de novo this structure and Arum-type colonization was observed. This study proves that the type of colonization is determined by the structure of the host, not by the fungus. Both the gametophyte and embryo foot have determined growth and Paris-type colonization, while, sporophyte roots have undetermined growth and Arum

  1. Water ferns Azolla spp. (Azollaceae as new host plants for the small China-mark moth, Cataclysta lemnata (Linnaeus, 1758 (Lepidoptera, Crambidae, Acentropinae

    Directory of Open Access Journals (Sweden)

    Atousa Farahpour-Haghani

    2017-01-01

    Full Text Available Water ferns (Azolla spp., Azollaceae are reported for the first time as host plants for the larvae of the small China-mark moth Cataclysta lemnata (Linnaeus (Lepidoptera: Crambidae: Acentropinae in rice fields and waterways of northern Iran. Cataclysta lemnata is a semi-aquatic species that has been recorded to feed on Lemnaceae and a few other aquatic plants. However, it has not been reported before on Azolla spp. Larvae use water fern as food source and shelter and, at high population density in the laboratory, they completely wiped water fern from the water surface. Feeding was confirmed after rearing more than eight continual generations of C. lemnata on water fern in the laboratory. Adults obtained this way are darker and have darker fuscous markings in both sexes compared with specimens previously reported and the pattern remains unchanged after several generations.

  2. Fern diversity and biomass at Chilapatta reserve forest of West Bengal Terai Duars in sub-humid tropical foothills of Indian eastern Himalayas

    Institute of Scientific and Technical Information of China (English)

    Gopal Shukla; Sumit Chakravarty

    2012-01-01

    We documented the status of fern diversity,biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division,West Bengal.Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters.Nineteen fern species were recorded,of which two are yet to be identified.Identified species were of eight families and nine genera.Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25.Fern density ranged from 93 to 13,403 individuals·ha-1.Most of the species were widely distributed.(IVI) values ranged from 7.54 to 37.45.The above ground portion of ferns accumulated the major portion ofbiomass and carbon.

  3. Cyclization of all-E- and 2Z-geranylfarnesols by a bacterial triterpene synthase: insight into sesterterpene biosynthesis in Aleuritopteris ferns.

    Science.gov (United States)

    Shinozaki, Junichi; Shibuya, Masaaki; Ebizuka, Yutaka; Masuda, Kazuo

    2013-01-01

    Aleuritopteris ferns produce triterpenes and sesterterpenes with tricyclic cheilanthane and tetracyclic 18-episcalarane skeletons. The structural and mechanistic similarities between both classes of fern terpene suggest that their biosynthetic enzymes may be closely related. We investigate here whether a triterpene synthase is capable of recognizing geranylfarnesols as a substrate, and is able to convert them to cyclic sesterterpenes. We found that a bacterial triterpene synthase converted all-E-geranylfarnesol (1b) into three scalarane sesterterpenes with 18αH stereochemistry (5, 7 and 8), as well as mono- and tricyclic sesterterpenes (6 and 9). In addition, 2Z-geranylfarnesol (4) was converted into an 18-episcalarane derivative (10), whose skeleton can be found in sesterterpenes isolated from Aleuritopteris ferns. These results provide insight into sesterterpene biosynthesis in Aleuritopteris ferns.

  4. Evaluation of angiosperm and fern contributions to soil organic matter using two methods of pyrolysis-gas chromatography-mass spectrometry

    Science.gov (United States)

    Plant biochemical characteristics influence decomposition rates and subsequently the biochemical composition of soil organic matter. Ferns, in particular have biochemical characteristics that could influence the stability of soil organic matter (SOM), such as high concentrations of aliphatic compou...

  5. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  6. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  7. Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica

    Directory of Open Access Journals (Sweden)

    Victoria Sosa

    2016-11-01

    Full Text Available Background Cloud forests, characterized by a persistent, frequent or seasonal low-level cloud cover and fragmented distribution, are one of the most threatened habitats, especially in the Neotropics. Tree ferns are among the most conspicuous elements in these forests, and ferns are restricted to regions in which minimum temperatures rarely drop below freezing and rainfall is high and evenly distributed around the year. Current phylogeographic data suggest that some of the cloud forest-adapted species remained in situ or expanded to the lowlands during glacial cycles and contracted allopatrically during the interglacials. Although the observed genetic signals of population size changes of cloud forest-adapted species including tree ferns correspond to predicted changes by Pleistocene climate change dynamics, the observed patterns of intraspecific lineage divergence showed temporal incongruence. Methods Here we combined phylogenetic analyses, ancestral area reconstruction, and divergence time estimates with climatic and altitudinal data (environmental space for phenotypic traits of tree fern species to make inferences about evolutionary processes in deep time. We used phylogenetic Bayesian inference and geographic and altitudinal distribution of tree ferns to investigate ancestral area and elevation and environmental preferences of Mesoamerican tree ferns. The phylogeny was then used to estimate divergence times and ask whether the ancestral area and elevation and environmental shifts were linked to climatic events and historical climatic preferences. Results Bayesian trees retrieved Cyathea, Alsophyla, Gymnosphaera and Sphaeropteris in monophyletic clades. Splits for species in these genera found in Mesoamerican cloud forests are recent, from the Neogene to the Quaternary, Australia was identified as the ancestral area for the clades of these genera, except for Gymnosphaera that was Mesoamerica. Climate tolerance was not divergent from

  8. Detection and mapping the spatial distribution of bracken fern weeds using the Landsat 8 OLI new generation sensor

    Science.gov (United States)

    Matongera, Trylee Nyasha; Mutanga, Onisimo; Dube, Timothy; Sibanda, Mbulisi

    2017-05-01

    Bracken fern is an invasive plant that presents serious environmental, ecological and economic problems around the world. An understanding of the spatial distribution of bracken fern weeds is therefore essential for providing appropriate management strategies at both local and regional scales. The aim of this study was to assess the utility of the freely available medium resolution Landsat 8 OLI sensor in the detection and mapping of bracken fern at the Cathedral Peak, South Africa. To achieve this objective, the results obtained from Landsat 8 OLI were compared with those derived using the costly, high spatial resolution WorldView-2 imagery. Since previous studies have already successfully mapped bracken fern using high spatial resolution WorldView-2 image, the comparison was done to investigate the magnitude of difference in accuracy between the two sensors in relation to their acquisition costs. To evaluate the performance of Landsat 8 OLI in discriminating bracken fern compared to that of Worldview-2, we tested the utility of (i) spectral bands; (ii) derived vegetation indices as well as (iii) the combination of spectral bands and vegetation indices based on discriminant analysis classification algorithm. After resampling the training and testing data and reclassifying several times (n = 100) based on the combined data sets, the overall accuracies for both Landsat 8 and WorldView-2 were tested for significant differences based on Mann-Whitney U test. The results showed that the integration of the spectral bands and derived vegetation indices yielded the best overall classification accuracy (80.08% and 87.80% for Landsat 8 OLI and WorldView-2 respectively). Additionally, the use of derived vegetation indices as a standalone data set produced the weakest overall accuracy results of 62.14% and 82.11% for both the Landsat 8 OLI and WorldView-2 images. There were significant differences {U (100) = 569.5, z = -10.8242, p < 0.01} between the classification accuracies

  9. Bioaccumulation of selected heavy metals by the water fern, Azolla filiculoides Lam. in a wetland ecosystem affected by sewage, mine and industrial pollution

    Energy Technology Data Exchange (ETDEWEB)

    Wet, L.P.D. de; Schoonbee, H.J.; Pretorius, J.; Bezuidenhout, L.M. (Rand Afrikaans University, Johannesburg (South Africa). Depts. of Zoology and Botany, Research Unit for Aquatic and Terrestrial Ecosystems)

    1990-10-01

    The bio-accumulation of the heavy metals, Fe, Cu, Ni, Pb, Zn, Mn and Cr by the water fern, Azolla filiculoides Lam. in a wetland ecosystem polluted by effluents from sewage works, mines and industries was investigated. Results showed that the different metals can be accumulated by the water fern at concentration levels not necessarily related to their actual concentrations in the aquatic environment, as measured in this case, in the bottom sediments. 45 refs., 1 fig., 3 tabs.

  10. Genome size evolution in Ontario ferns (Polypodiidae): evolutionary correlations with cell size, spore size, and habitat type and an absence of genome downsizing.

    Science.gov (United States)

    Henry, Thomas A; Bainard, Jillian D; Newmaster, Steven G

    2014-10-01

    Genome size is known to correlate with a number of traits in angiosperms, but less is known about the phenotypic correlates of genome size in ferns. We explored genome size variation in relation to a suite of morphological and ecological traits in ferns. Thirty-six fern taxa were collected from wild populations in Ontario, Canada. 2C DNA content was measured using flow cytometry. We tested for genome downsizing following polyploidy using a phylogenetic comparative analysis to explore the correlation between 1Cx DNA content and ploidy. There was no compelling evidence for the occurrence of widespread genome downsizing during the evolution of Ontario ferns. The relationship between genome size and 11 morphological and ecological traits was explored using a phylogenetic principal component regression analysis. Genome size was found to be significantly associated with cell size, spore size, spore type, and habitat type. These results are timely as past and recent studies have found conflicting support for the association between ploidy/genome size and spore size in fern polyploid complexes; this study represents the first comparative analysis of the trend across a broad taxonomic group of ferns.

  11. Methyl chloride emission from a fern growing in sub-tropical, temperate and cool-temperate climates

    Science.gov (United States)

    Yokouchi, Yoko; Takenaka, Akio; Miyazaki, Yuzo; Kawamura, Kimitaka; Hiura, Tsutomu

    2015-04-01

    Methyl chloride(CH3Cl) is the most abundant halocarbon in the troposphere, and is known as a natural stratospheric ozone depletion compound. Amongst its various sources, tropical forests are likely the largest contributor, followed by biomass burning, oceans and salt marshes. There have been unsolved questions why CH3Cl-emitting plants are dominated by tropical plants. Recently we found that a fern, Osmunda japonica, collected from temperate zone emits as high as several μg-g(dw)-1-h-1 of CH3Cl. This fern has a wide natural distribution, covering sub-tropical, temperate and cool-temperate climate, making it possible to study the CH3Cl emission rate from one species under different climate conditions. In this presentation, we report seasonal and spatial variation of the CH3Cl emission rate from O. japonica, and discuss its controlling factors.

  12. Mycorrhizal-like interaction between gametophytes and young sporophytes of the fern Dryopteris muenchii (Filicales) and its fungal endophyte.

    Science.gov (United States)

    Reyes-Jaramillo, Irma; Camargo-Ricalde, Sara Lucía; Aquiahuatl-Ramos, Ma de los Angeles

    2008-09-01

    The morphology of a Glomus-like fungus-host interaction in chlorophyllous gametophytes and young apogamic sporophytes of Dryopteris muenchii A.R. Sm. was studied from ferns cultivated in laboratory, using soil as substrate. An aseptate fungus colonized the gametophytes' tissue through the rhizoids, developing vesicles. The fungus penetrated the young sporophytes primary roots by developing appressoria. It spread forming inter- and intra-cellular hyphae through the epidermis and the outermost cortical cell layers, where it formed vesicles, hyphal coils-like and arbuscules. The fungus hyphae never colonized the gametophyte-sporophyte cellular junction. The fungal structures observed on D. muenchii during this study, are rather similar to those reported for the plant host-arbuscular mycorrhizal fungus (AMF) interaction, where the AMF described belonged to Phylum Glomeromycota. Therefore, this study is a contribution to the scarce knowledgement of the association between AMF and chlorophyllous gametophytes and young apogamic sporophytes of ferns.

  13. Effect of enhanced nitrogen input on release of nutrients and nutrient availability in stands of tall fern Athyrium distentifolium

    Science.gov (United States)

    Tå¯Ma, Ivan; Holuib, Petr; Záhora, Jaroslav; Fiala, Karel

    2010-05-01

    Improved light conditions, after destruction of tree canopy, soil acidification and increased nitrogen availability, support intensive spreading of acidophilous perennial grasses and stands of tall fern (Athyrium distentifolium) on deforested sites in the Moravian-Silesian Beskydy Mts. (the Czech Republic). The aim of the study was to determine how higher inputs of nitrogen affect the release of nutrients during decomposition processes of fern litter. The experimental site was chosen on a southwest-facing slope of the Kněhyně Mt. (49o31´ N, 18o 32´E, 1170 m a.s.l.) in the Moravian-Silesin Beskydy Mts. in the Czech Republic. The area is characterized by an annual mean air temperature of 5.6 oC and annual precipitation of 1110 mm. A large fern stand was divided in four blocks (5x3 m) and on two of them higher doses of nitrogen were applied (50 kgN/ha in five doses in the course of the growing season). Similarly, mesh-bags with fresh natural litter of fern were used to determine rate of litter decomposition during one year. Samples were inserted in both nitrogen treated and untreated fern stands in autumn 2006 and 2007 collected in autumn 2007 and 2008. On the basis of litter amount estimated at the start and at the end of exposure and of actual content of minerals in original and exposed litter, the release and/or accumulation of minerals during decomposition were calculated. The availability (more or less in the case of ammonia-nitrogen) and movement of percolated nitrogen (mainly in the case of nitrate-nitrogen) was estimated in situ by the trapping of mineral N into the ion exchange resin (IER) inserted into special cover. The decomposition rate of native A. distentifolium litter was approximately the same (29-30 %) at both nitrogen availability, however the element release from decomposed litter was higher for N, P and Ca in both years and for K and Mg in the first year as well. However, decomposition rate of cellulose was two times greater in fern stands

  14. Distribution of drimane sesquiterpenoids and tocopherols in liverworts, ferns and higher plants: Polygonaceae, Canellaceae and Winteraceae species.

    Science.gov (United States)

    Asakawa, Yoshinori; Ludwiczuk, Agnieszka; Harinantenaina, Liva; Toyota, Masao; Nishiki, Mayumi; Bardon, Alicia; Nii, Kaeko

    2012-06-01

    The liverwort, Porella vernicosa complex produces a very hot tasting polygodial, a drimane-type sesquiterpene dialdehyde. The same compound has been isolated from two ferns, Thelypteris hispidula and Blechnum fluviatile, as well as from the higher plants Polygonum hydropiper, P. hydropiper f. purpurascens (Polygonaceae), Cinnamosma, Caspicodendron, Canella and Warburgia species (Canellaceae), and Pseudowintera colorata, Tasmannia lanceolata, Drimys and Zygogynum species (Winteraceae). In addition, the liverworts and higher plants which elaborate polygodial and its related pungent drimane dials contain a small amount of alpha-tocopherol, gamma-tocopherol or delta-tocotrienol. The present paper gives the results of a comparative study on the drimane-type sesquiterpenoids in some liverworts, ferns and higher plants, and the role of tocopherols in these plant groups.

  15. El cálculo de estructuras en la obra de Carlos Fernández Casado

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    Alarcón, Enrique

    2008-03-01

    Full Text Available In the present paper the contributions of Carlos Fernández Casado to Structural Analysis are reviewed. After a description of the international context he was working in, his contributions and their relation to the academic training he received at the Civil Engineering Scholl in Madrid are described. Finally the most interesting aspects of his written work are commented.En este artículo se analizan las aportaciones de Carlos Fernández Casado al cálculo de estructuras. Tras exponer el contexto internacional, se describen sus contribuciones y su relación con la formación que recibió en la Escuela de Ingenieros de Caminos de Madrid. Se finaliza indicando algunos de los méritos más interesantes de su obra escrita.

  16. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L).

    Science.gov (United States)

    Du, Xin; Cui, Yanshan; Weng, Liping; Cao, Qing; Zhu, Yongguan

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted soil at 1 and 3%. After aging for one, three, and six months, germinated wheat was planted in the soil. After two months, wheat plants were harvested. Results showed that As concentration in shoots and roots significantly increased with increasing amounts of As-rich leaf additions in soil samples and decreased over the incubation time (p bioavailability. Arsenic concentrations in shoots and roots could be well described with linear functions of As concentrations distributed in different fractions. In conclusion, aging effect should be considered during risk assessment of As in soil-plant systems where As is recycled by the plant.

  17. Applying DNA Barcodes to Identify Closely Related Species of Ferns: A Case Study of the Chinese Adiantum (Pteridaceae).

    Science.gov (United States)

    Wang, Fan-Hong; Lu, Jin-Mei; Wen, Jun; Ebihara, Atsushi; Li, De-Zhu

    2016-01-01

    DNA barcoding is a fast-developing technique to identify species by using short and standard DNA sequences. Universal selection of DNA barcodes in ferns remains unresolved. In this study, five plastid regions (rbcL, matK, trnH-psbA, trnL-F and rps4-trnS) and eight nuclear regions (ITS, pgiC, gapC, LEAFY, ITS2, IBR3_2, DET1, and SQD1_1) were screened and evaluated in the fern genus Adiantum from China and neighboring areas. Due to low primer universality (matK) and/or the existence of multiple copies (ITS), the commonly used barcodes matK and ITS were not appropriate for Adiantum. The PCR amplification rate was extremely low in all nuclear genes except for IBR3_2. rbcL had the highest PCR amplification rate (94.33%) and sequencing success rate (90.78%), while trnH-psbA had the highest species identification rate (75%). With the consideration of discriminatory power, cost-efficiency and effort, the two-barcode combination of rbcL+ trnH-psbA seems to be the best choice for barcoding Adiantum, and perhaps basal polypod ferns in general. The nuclear IBR3_2 showed 100% PCR amplification success rate in Adiantum, however, it seemed that only diploid species could acquire clean sequences without cloning. With cloning, IBR3_2 can successfully distinguish cryptic species and hybrid species from their related species. Because hybridization and allopolyploidy are common in ferns, we argue for including a selected group of nuclear loci as barcodes, especially via the next-generation sequencing, as it is much more efficient to obtain single-copy nuclear loci without the cloning procedure.

  18. Impact of mycorrhization on the abundance, growth and leaf nutrient status of ferns along a tropical elevational gradient.

    Science.gov (United States)

    Kessler, Michael; Güdel, Ramona; Salazar, Laura; Homeier, Jürgen; Kluge, Jürgen

    2014-07-01

    Mycorrhizal fungi are crucial for the ecological success of land plants, providing their hosts with nutrients in exchange for organic C. However, not all plants are mycorrhizal, especially ferns, of which about one-third of the species lack this symbiosis. Because the mycorrhizal status is evolutionarily ancestral, this lack of mycorrhizae must have ecological advantages, but what these advantages are and how they affect the competitive ability of non-mycorrhizal plants under natural conditions is currently unknown. To address this uncertainty, we studied terrestrial fern assemblages and species abundances as well as their mycorrhization status, leaf nutrient concentration and relative annual growth along an elevational gradient in the Ecuadorian Andes (500-4,000 m). We surveyed the mycorrhizal status of 375 root samples belonging to 85 species, and found mycorrhizae in 89% of the samples. The degree of mycorrhization decreased with elevation but was unrelated to soil nutrients. Species with mycorrhizae were significantly more abundant than non-mycorrhizal species, but non-mycorrhizal species had significantly higher relative growth and concentrations of leaf N, P, Mg, and Ca. Our study thus shows that despite lower abundances, non-mycorrhizal fern species did not appear to be limited in their growth or nutrient supply relative to mycorrhizal ones. As a basis for future studies, we hypothesize that non-mycorrhizal fern species may be favoured in special microhabitats of the forest understory with high soil nutrient or water availability, or that the ecological benefit of mycorrhizae is not related to nutrient uptake but rather to, for example, pathogen resistance.

  19. Some New Records of Ferns from Vietnam (2)%越南蕨类植物新记载(2)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nine species of ferns are reported for the first time from Vietnam:Cyrtomium pachyphyllum (Rosenst.)C.Chr.,C.shingianum H.S.Kung et P.S.Wang,Dryopteri bodinieri (Christ) C.Chr.,D.gymnosora (Makino)C.Chr.,Teratophyllum aculeatum(Bl.) Mett.ex Kuhn,Elaphoglossunm sinii C.Chr.ex Wu,Tectaria herpetocaulos Holtt.,T.hokouensis Ching et C.H.Wang,Boniniella cardiophylla (Hance) Tagawa,distributions are discussed.

  20. Photoproduction of hydrogen by a non-sulphur bacterium isolated from root zones of water fern Azolla pinnata

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Srivastava, S.C.; Pandey, K.D. (Banaras Hindu Univ., Varanasi (IN). Centre of Advanced Study in Botany)

    1990-01-01

    A photosynthetic bacterium Rhodopseudomonas sp. BHU strain 1 was isolated from the root zone of water fern Azolla pinnata. The bacterium was found to produce hydrogen with potato starch under phototrophic conditions. The immobilized bacterial cells showed sustained hydrogen production with a more than 4-fold difference over free cell suspensions. The data have been discussed in the light of possible utilization of relatively cheaper raw materials by non-sulphur bacteria to evolve hydrogen. (author).

  1. Rates of ecological divergence and body size evolution are correlated with species diversification in scaly tree ferns.

    Science.gov (United States)

    Ramírez-Barahona, Santiago; Barrera-Redondo, Josué; Eguiarte, Luis E

    2016-07-13

    Variation in species richness across regions and between different groups of organisms is a major feature of evolution. Several factors have been proposed to explain these differences, including heterogeneity in the rates of species diversification and the age of clades. It has been frequently assumed that rapid rates of diversification are coupled to high rates of ecological and morphological evolution, leading to a prediction that remains poorly explored for most species: the positive association between ecological niche divergence, morphological evolution and species diversification. We combined a time-calibrated phylogeny with distribution, ecological and body size data for scaly tree ferns (Cyatheaceae) to test whether rates of species diversification are predicted by the rates at which clades have evolved distinct ecological niches and body sizes. We found that rates of species diversification are positively correlated with rates of ecological and morphological evolution, with rapidly diversifying clades also showing rapidly evolving ecological niches and body sizes. Our results show that rapid diversification of scaly tree ferns is associated with the evolution of species with comparable morphologies that diversified into similar, yet distinct, environments. This suggests parallel evolutionary pathways opening in different tropical regions whenever ecological and geographical opportunities arise. Accordingly, rates of ecological niche and body size evolution are relevant to explain the current patterns of species richness in this 'ancient' fern lineage across the tropics. © 2016 The Author(s).

  2. Variable frequency of plastid RNA editing among ferns and repeated loss of uridine-to-cytidine editing from vascular plants.

    Science.gov (United States)

    Guo, Wenhu; Grewe, Felix; Mower, Jeffrey P

    2015-01-01

    The distinct distribution and abundance of C-to-U and U-to-C RNA editing among land plants suggest that these two processes originated and evolve independently, but the paucity of information from several key lineages limits our understanding of their evolution. To examine the evolutionary diversity of RNA editing among ferns, we sequenced the plastid transcriptomes from two early diverging species, Ophioglossum californicum and Psilotum nudum. Using a relaxed automated approach to minimize false negatives combined with manual inspection to eliminate false positives, we identified 297 C-to-U and three U-to-C edit sites in the O. californicum plastid transcriptome but only 27 C-to-U and no U-to-C edit sites in the P. nudum plastid transcriptome. A broader comparison of editing content with the leptosporangiate fern Adiantum capillus-veneris and the hornwort Anthoceros formosae uncovered large variance in the abundance of plastid editing, indicating that the frequency and type of RNA editing is highly labile in ferns. Edit sites that increase protein conservation among species are more abundant and more efficiently edited than silent and non-conservative sites, suggesting that selection maintains functionally important editing. The absence of U-to-C editing from P. nudum plastid transcripts and other vascular plants demonstrates that U-to-C editing loss is a recurrent phenomenon in vascular plant evolution.

  3. Inorganic and organic nitrogen acquisition by a fern Dicranopteris dichotoma in a subtropical forest in South China.

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    Xingliang Xu

    Full Text Available The fern Dicranopteris dichotoma is an important pioneer species of the understory in Masson pine (Pinus massoniana forests growing on acidic soils in the subtropical and tropical China. To improve our understanding of the role of D. dichotoma in nitrogen (N uptake of these forests, a short-term (15N experiment was conducted at mountain ridge (MR, with low N level and mountain foot (MF, with high N level. We injected (15N tracers as (15NH4, (15NO3 or (15N-glycine into the soil surrounding each plant at both MR and MF sites. Three hours after tracer injection, the fern D. dichotoma took up 15NH4+ significantly faster at MF than at MR, but it showed significantly slower uptake of (15NO3- at MF than at MR. Consequently, (15NO3- made greater contribution to the total N uptake (50% to the total N uptake at MR than at MF, but (15N-glycine only contributed around 11% at both sites. Twenty-four hours after tracer injection, D. dichotoma preferred (15NH4+ (63% at MR, whereas it preferred (15NO3- (47% at MF. We concluded that the D. dichotoma responds distinctly in its uptake pattern for three available N species over temporal and spatial scales, but mainly relies on inorganic N species in the subtropical forest. This suggests that the fern employs different strategies to acquire available N which depends on N levels and time.

  4. Arsenic accumulation by the aquatic fern Azolla: Comparison of arsenate uptake, speciation and efflux by A. caroliniana and A. filiculoides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xin [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Lin Aijun [Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhao Fangjie [Soil Science Department, Rothamsted Research, Hertfordshire AL5 2JQ (United Kingdom); Xu Guozhong [Agricultural Ecology Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350013 (China); Duan Guilan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhu Yongguan [State Key Lab of Urban and ONAL Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361003 (China)], E-mail: ygzhu@rcees.ac.cn

    2008-12-15

    This study investigates As accumulation and tolerance of the aquatic fern Azolla. Fifty strains of Azolla showed a large variation in As accumulation. The highest- and lowest-accumulating ferns among the 50 strains were chosen for further investigations. Azolla caroliniana accumulated two times more As than Azolla filiculoides owing to a higher influx velocity for arsenate. A. filiculoides was more resistant to external arsenate due to a lower uptake. Both strains showed a similar degree of tolerance to internal As. Arsenate and arsenite were the dominant As species in both Azolla strains, with methlyated As species accounting for <5% of the total As. A. filiculoides had a higher proportion of arsenite than A. caroliniana. Both strains effluxed more arsenate than arsenite, and the amount of As efflux was proportional to the amount of As accumulation. The potential of growing Azolla in paddy fields to reduce As transfer from soil and water to rice should be further evaluated. - Arsenic accumulation and efflux differ between strains of the aquatic fern Azolla.

  5. Dynamics of asymmetrical hybridization in North American wood ferns: reconciling patterns of inheritance with gametophyte reproductive biology.

    Science.gov (United States)

    Testo, Weston L; Watkins, James E; Barrington, David S

    2015-04-01

    Hybridization is an important evolutionary force in plants, but the mechanisms underlying it have not been well studied for many groups. In particular, the drivers of non-random patterns of interspecific gene flow (asymmetrical hybridization) remain poorly understood, especially in the seed-free vascular plants. Here, we examine patterns of asymmetrical hybridization in two widespread fern hybrids from eastern North America and study the role of gametophyte ecology in the determination of hybridization bias. We characterized the maternal parentage of > 140 hybrid sporophytes by sequencing a c. 350-bp region of chloroplast DNA (cpDNA). To identify factors contributing to patterns of asymmetrical hybridization, we cultured gametophytes of the parental species and evaluated critical aspects of their reproductive biology. We found that asymmetrical hybridization was prevalent across the populations of both hybrids. Reproductive traits varied across species and suggest that selfing potential, antheridiogen responsiveness, sperm dispersal capacity and gamete size all contribute to the mediation of the direction of hybridization in this group. Our findings suggest that asymmetrical hybridization in ferns is driven by an array of reproductive traits. This study helps to sharpen and define a mechanistic understanding of patterns of hybridization in this group and demonstrates the importance of considering gametophyte biology when studying evolutionary processes in ferns.

  6. Plant Resource of Ornamental Fern in Jiangxi Province%江西省观赏蕨类植物资源

    Institute of Scientific and Technical Information of China (English)

    梁芳; 曹岚; 王治

    2011-01-01

    The plant resource of ornamental fem in Jiangxi Province was investigated, the results showed that there were 233 species, 97 genera , 47 families of ornamental ferns in Jiangxi Province, and they could be divided into 5 types (terrestrial fern, epiphytic fern, rock fem, vine fem and aquatic fem) according to the ecotype. Some have local characteristics could choose for development and utilization. Some have local characteristics could choose for development and utilization.%对江西省观赏蕨类植物资源进行了调查.结果表明,江西省共有观赏蕨类植物47科97属233种,按生态类型不同可将其分为陆生蕨、附生蕨、石生蕨、藤本蕨和水生蕨共5类,可应用于园林绿化、盆栽观赏、切花配叶等方面.可选择具有地方特色的种类进行开发利用.

  7. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective.

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    G Arjen de Groot

    Full Text Available Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes--while playing an essential role in fern colonization and reproduction--generally lack the morphological complexity for morphology-based identification and have therefore been underappreciated in ecological studies. We evaluated the potential of a combination of rbcL with a noncoding plastid marker, trnL-F, to obtain DNA-identifications for fern species. A regional approach was adopted, by creating a reference database of trusted rbcL and trnL-F sequences for the wild-occurring homosporous ferns of NW-Europe. A combination of parsimony analyses and distance-based analyses was performed to evaluate the discriminatory power of the two-region barcode. DNA was successfully extracted from 86 tiny fern gametophytes and was used as a test case for the performance of DNA-based identification. Primer universality proved high for both markers. Based on the combined rbcL + trnL-F dataset, all genera as well as all species with non-equal chloroplast genomes formed their own well supported monophyletic clade, indicating a high discriminatory power. Interspecific distances were larger than intraspecific distances for all tested taxa. Identification tests on gametophytes showed a comparable result. All test samples could be identified to genus level, species identification was well possible unless they belonged to a pair of Dryopteris species with completely identical chloroplast genomes. Our results suggest a high potential of the combined use of rbcL and trnL-F as a two-locus cpDNA barcode for identification of fern species. A regional approach may be preferred for ecological tests. We here offer such a ready-to-use barcoding approach for ferns, which opens the way for answering a

  8. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective.

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo J; Maas, Jan W; Schneider, Harald; Vogel, Johannes C; Erkens, Roy H J

    2011-01-26

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes--while playing an essential role in fern colonization and reproduction--generally lack the morphological complexity for morphology-based identification and have therefore been underappreciated in ecological studies. We evaluated the potential of a combination of rbcL with a noncoding plastid marker, trnL-F, to obtain DNA-identifications for fern species. A regional approach was adopted, by creating a reference database of trusted rbcL and trnL-F sequences for the wild-occurring homosporous ferns of NW-Europe. A combination of parsimony analyses and distance-based analyses was performed to evaluate the discriminatory power of the two-region barcode. DNA was successfully extracted from 86 tiny fern gametophytes and was used as a test case for the performance of DNA-based identification. Primer universality proved high for both markers. Based on the combined rbcL + trnL-F dataset, all genera as well as all species with non-equal chloroplast genomes formed their own well supported monophyletic clade, indicating a high discriminatory power. Interspecific distances were larger than intraspecific distances for all tested taxa. Identification tests on gametophytes showed a comparable result. All test samples could be identified to genus level, species identification was well possible unless they belonged to a pair of Dryopteris species with completely identical chloroplast genomes. Our results suggest a high potential of the combined use of rbcL and trnL-F as a two-locus cpDNA barcode for identification of fern species. A regional approach may be preferred for ecological tests. We here offer such a ready-to-use barcoding approach for ferns, which opens the way for answering a whole range of

  9. La Galicia que vio nacer y crecer a Gregorio Fernández

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    Saavedra, Pegerto

    2010-12-01

    Full Text Available The great sculptor Gregorio Fernández was born in Galicia; that territory was very different from the city of Valladolid, where he worked and died. Fhe changes caused by the Catholici Reformation progressed slowly and with difficulty en the old Galician Kingdom. The absence of towns prevailed in that period, and most of Glaician people lived in small villages that were far from urban civilization. They were not instructed in Christian doctrine and besides they had their peculiar customs, such as feeding on brown bread and bacon. This cultural and social context generated a negative opinion about Galicia and Galician people in the middle of the XVIth century. Don Diego Samiento de Acuña, first earl of Gondomar, and Don Pedro Fernández de Castro, seventh earl of Lemos, were opposed to this negative opinion, although they had an unfortunate outcome. First, Gondomar -who owned an important library in his house in Valladolid- and his circle wrote spirited chorographical and historiographical works. On the other hand, Gondomar and Lemos presented several claims in the Royal Court from Galician nobility and clergy al the end of XVIth century and at the beginning of the XVIIth century.

    La Galicia en la que nació el formidable escultor Gregorio Fernández tenía poco que ver con la ciudad de Valladolid, en la desarrolló su trabajo y falleció. El viejo Reino gallego era un territorio ruralizado, en el que los cambios ligados a la reforma tridentina avanzaban con lentitud y dificultad. La ausencia de grandes núcleos de población y la rudeza de unos campesinos que vivían en minúsculos asentamientos dispersos, alejados de la civilización por su ignorancia de los rudimentos de la catequesis y por sus costumbres, entre ellas la de alimentarse de pan negro y tocino, son realidades que están en el origen de la caudalosa corriente de tópicos negativos que desde mediados del XVI comenzó a correr sobre el Reino y sus habitantes, y que, con poco

  10. Molecular circumscription and major evolutionary lineages of the fern genus Dryopteris (Dryopteridaceae

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    Zhang Li-Bing

    2012-09-01

    Full Text Available Abstract Background The fern genus Dryopteris (Dryopteridaceae is among the most common and species rich fern genera in temperate forests in the northern hemisphere containing 225–300 species worldwide. The circumscription of Dryopteris has been controversial and various related genera have, over the time, been included in and excluded from Dryopteris. The infrageneric phylogeny has largely remained unclear, and the placement of the majority of the supraspecific taxa of Dryopteris has never been tested using molecular data. Results In this study, DNA sequences of four plastid loci (rbcL gene, rps4-trnS spacer, trnL intron, trnL-F spacer were used to reconstruct the phylogeny of Dryopteris. A total of 122 accessions are sampled in our analysis and they represent 100 species of the expanded Dryopteris including Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema. All four subgenera and 19 sections currently recognized in Dryopteris s.s. are included. One species each of Arachniodes, Leptorumohra, and Lithostegia of Dryopteridaceae are used as outgroups. Our study confirms the paraphyly of Dryopteris and provides the first strong molecular evidence on the monophyly of Acrophorus, Diacalpe, Dryopsis, Nothoperanema, and Peranema. However, all these monophyletic groups together with the paraphyletic Acrorumohra are suggested to be merged into Dryopteris based on both molecular and morphological evidence. Our analysis identified 13 well-supported monophyletic groups. Each of the 13 clades is additionally supported by morphological synapomophies and is inferred to represent a major evolutionary lineage in Dryopteris. In contrast, monophyly of the four subgenera and 15 out of 19 sections currently recognized in Dryopteris s.s is not supported by plastid data. Conclusions The genera, Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema, should all be merged into Dryopteris. Most species of these genera share a

  11. Desiccation tolerance of Hymenophyllacea filmy ferns is mediated by constitutive and non-inducible cellular mechanisms.

    Science.gov (United States)

    Garcés Cea, Marcelo; Claverol, Stephan; Alvear Castillo, Carla; Rabert Pinilla, Claudia; Bravo Ramírez, León

    2014-04-01

    The Hymenophyllaceae is a primitive family within the Filicopsidae. One of the most exceptional features of this family of ferns is the presence of fronds with one or just a few cell layers (hence their name of filmy ferns), and the absence of stomata. Hymenophyllum caudiculatum and Hymenophyllum dentatum are able to lose more than 82% of their fully hydrated water content, to remain dry for extended periods of time (days or weeks), and to survive and remain viable following rehydration. The aim of this work was to understand whether the adaptive strategy of the Hymenophyllaceae for desiccation tolerance is constitutive or inducible. A proteomic approach was adopted in combination with physiological parameters to assess whether there were changes in the protein content during dehydration and following rehydration. Detached fronds were used to monitor the rates of photosynthesis in desiccation experiments, sugar accumulation, and high-resolution 2-DE to analyze proteome variation during a desiccation-rehydration cycle. The analyzed proteome exhibited little variation (3-4%) between hydrated and desiccated states, while variation was greater between the desiccated and rehydrated states (8.7-10%). Eighty-two discrete proteins were analyzed by MS/MS, and 65 were identified. About 21% of the analyzed proteins (17) were mixtures of two or more different polypeptides. Of the identified proteins, more than a half (33 spots, 55%) had functions related to energy-photosynthesis. The second largest category with known function (five spots, 8%) was related to cell rescue, defense, and virulence. More than one in every four proteins analyzed belonged to a group of hypothetical proteins (18 spots, 28%). The results suggest that the Hymenophyllaceae represent an example of a change in adaptive strategy from a typical vascular to the poikilohydric homoiochlorophyllous adaptation, which they share with the bryophytes that grow in profusion in the same habitats. The speed at which

  12. Synthesizing research and education: Ecology and genetics of independent fern gametophytes and teaching science inquiry and content through simulations

    Science.gov (United States)

    Duffy, Aaron M.

    Two of the main areas of focus in university academics are research and education. The mission statements of Utah State University and the Department of Biology emphasize both areas, as do the requirements of funding agencies. I attempted to integrate research and education by using tools that I developed to support and inform my biological research projects to teach science. Ferns have a life cycle with alternating haploid and diploid life stages, both of which are free-living and potentially long-lived. The haploid gametophytes of some ferns reproduce asexually and may have different environmental requirements than the diploid sporophytes, so it is possible for populations of gametophytes to exist without sporophytes. This dissertation includes a description of surveys for Hymenophyllum wrightii, a fern with independent gametophytes in the Pacific Northwest, and improves our understanding of the range, distribution, and habitat requirements of these plants which were previously assumed to be rare. It also describes an attempt to explore the population genetics of gametophytes of Crepidomanes intricatum, a widespread fern in the Appalachian Mountains for which no sporophytes have ever been found. To help visualize evolutionary processes in independent gametophyte populations I developed the Virtual Population Genetics Simulator (VPGsim) to simulate populations of ferns in a 3-dimensional environment. This dissertation includes a description of VPGsim, a learning module using it to teach undergraduate genetics, and a study demonstrating its effectiveness at improving students' understanding of science content and confidence in their ability to perform science inquiry. That simulation tool led to a collaboration to find other ways to teach science with simulations, and to the development of a Virtual Plant Community simulator (VPCsim) for teaching middle school students about the effects of the environment and human impacts on living organisms. This dissertation

  13. Inter-and intraspecific variation in fern mating systems after long-distance colonization: the importance of selfing

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    de Groot G Arjen

    2012-01-01

    Full Text Available Abstract Background Previous studies on the reproductive biology of ferns showed that mating strategies vary among species, and that polyploid species often show higher capacity for self-fertilization than diploid species. However, the amount of intraspecific variation in mating strategy and selfing capacity has only been assessed for a few species. Yet, such variation may have important consequences during colonization, as the establishment of any selfing genotypes may be favoured after long-distance dispersal (an idea known as Baker's law. Results We examined intra-and interspecific variation in potential for self-fertilization among four rare fern species, of which two were diploids and two were tetraploids: Asplenium scolopendrium (2n, Asplenium trichomanes subsp. quadrivalens (4n, Polystichum setiferum (2n and Polystichum aculeatum (4n. Sporophyte production was tested at different levels of inbreeding, by culturing gametophytes in isolation, as well as in paired cultures with a genetically different gametophyte. We tested gametophytes derived from various genetically different sporophytes from populations in a recently planted forest colonized through long-distance dispersal (Kuinderbos, the Netherlands, as well as from older, less disjunct populations. Sporophyte production in isolation was high for Kuinderbos genotypes of all four species. Selfing capacity did not differ significantly between diploids and polyploids, nor between species in general. Rather selfing capacity differed between genotypes within species. Intraspecific variation in mating system was found in all four species. In two species one genotype from the Kuinderbos showed enhanced sporophyte production in paired cultures. For the other species, including a renowned out crosser, selfing capacity was consistently high. Conclusions Our results for four different species suggest that intraspecific variation in mating system may be common, at least among temperate calcicole

  14. Sporangium Exposure and Spore Release in the Peruvian Maidenhair Fern (Adiantum peruvianum, Pteridaceae.

    Directory of Open Access Journals (Sweden)

    Simon Poppinga

    Full Text Available We investigated the different processes involved in spore liberation in the polypod fern Adiantum peruvianum (Pteridaceae. Sporangia are being produced on the undersides of so-called false indusia, which are situated at the abaxial surface of the pinnule margins, and become exposed by a desiccation-induced movement of these pinnule flaps. The complex folding kinematics and functional morphology of false indusia are being described, and we discuss scenarios of movement initiation and passive hydraulic actuation of these structures. High-speed cinematography allowed for analyses of fast sporangium motion and for tracking ejected spores. Separation and liberation of spores from the sporangia are induced by relaxation of the annulus (the 'throwing arm' of the sporangium catapult and conservation of momentum generated during this process, which leads to sporangium bouncing. The ultra-lightweight spores travel through air with a maximum velocity of ~5 m s(-1, and a launch acceleration of ~6300 g is measured. In some cases, the whole sporangium, or parts of it, together with contained spores break away from the false indusium and are shed as a whole. Also, spores can stick together and form spore clumps. Both findings are discussed in the context of wind dispersal.

  15. Arundina graminifolia var. revoluta (Arethuseae, Orchidaceae) has fern-type rheophyte characteristics in the leaves.

    Science.gov (United States)

    Yorifuji, Eri; Ishikawa, Naoko; Okada, Hiroshi; Tsukaya, Hirokazu

    2015-03-01

    Morphological and molecular variation between Arundina graminifolia var. graminifolia and the dwarf variety, A. graminifolia var. revoluta, was examined to assess the validity of their taxonomic characteristics and genetic background for identification. Morphological analysis in combination with field observations indicated that A. graminifolia var. revoluta is a rheophyte form of A. graminifolia characterized by narrow leaves, whereas the other morphological characteristics described for A. graminifolia var. revoluta, such as smaller flowers and short stems, were not always accompanied by the narrower leaf phenotype. Molecular analysis based on matK sequences indicated that only partial differentiation has occurred between A. graminifolia var. graminifolia and A. graminifolia var. revoluta. Therefore, we should consider the rheophyte form an ecotype rather than a variety. Anatomical observations of the leaves revealed that the rheophyte form of A. graminifolia possessed characteristics of the rheophytes of both ferns and angiosperms, such as narrower palisade tissue cells and thinner spongy tissue cells, as well as fewer cells in the leaf-width direction and fewer mesophyll cell layers.

  16. Antibacterial activity of some ethno-botanically important ferns of Southern Assam, India

    Directory of Open Access Journals (Sweden)

    Kathakali Nath

    2016-08-01

    Full Text Available Pteridophytes form an important part of the biodiversity of this blue green planet. It has been agreed by recent workers that pteridophytic population of India is about 10% of the total pteridophytic flora of the world. Besides showing economic values towards food and fodder, indicators, bio fertilizers, insect repellents etc. quiet a large number of pteridophytic species are used by different communities as medicine and folk medicines. They treat cuts and wounds and many other diseases with leaf extract/rhizome extract of pteridophytes. The tribal people of Barak Valley area of Southern Assam, are using different species of pteridophytes to cure various diseases. In the present communication, total 21 species of common pteridophytes were enumerated from Barak Valley. The ethnobotanical importance of these species as reported by different authors were reviewed and presented in tabulated form. Further, frond extract of these species were tested against five potentially pathogenic microorganisms. The result showed that 10 species have antibacterial activity against one or more organisms while the remaining 11 species did not show any activity against any of the test organisms. The ferns showing antibacterial activity are Adiantum capillus-veneris, Asplenium nidus, Cyathea brunoniana, Cyathea gigantea, Dipteris wallichii, Drynaria quercifolia, Lygodium japonicum, Lygodium flexuossum, Pityrograma calomelanos, and Pteris biaurita.

  17. Exploring the origin of the latitudinal diversity gradient: Contrasting the sister fern genera Phegopteris and Pseudophegopteris

    Institute of Scientific and Technical Information of China (English)

    Harald SCHNEIDER; Li-Juan HE; Jeannine MARQUARDT; Li WANG; Jochen HEINRICHS; Sabine HENNEQUIN; Xian-Chun ZHANG

    2013-01-01

    The origin of the latitudinal biodiversity gradient has been studied using various approaches.Here,we employ a comparative phylogenetic approach to infer evidence for the hypothesis that differences in diversification rates are one of the main factors contributing to the assembly of this gradient.We infer the phylogeny of the two sister genera Phegopteris and Pseudophegopteris.The two genera are distinct in their species richness (4 vs.20 spp.) and their preferences to temperate to subtropical (Phegopteris) or tropical climates (Pseudophegopteris).Using sequences of three plastid DNA regions,we confirm the monophyly of each genus and infer the inter-and intra-generic phylogenetic differentiation of the sister clades.We recover evidence for distinct net-diversification rate between the two genera,which may be caused either by a higher extinction risk of temperate Phegopteris or a higher speciation rate of tropical Pseudophegopteris.We discuss our results in the context of our current knowledge on the speciation processes of ferns.We conclude on the crucial influence of other factors such as the rise of the Himalaya on the diversification of these fems.

  18. Conflict amongst chloroplast DNA sequences obscures the phylogeny of a group of Asplenium ferns.

    Science.gov (United States)

    Shepherd, Lara D; Holland, Barbara R; Perrie, Leon R

    2008-07-01

    A previous study of the relationships amongst three subgroups of the Austral Asplenium ferns found conflicting signal between the two chloroplast loci investigated. Because organelle genomes like those of chloroplasts and mitochondria are thought to be non-recombining, with a single evolutionary history, we sequenced four additional chloroplast loci with the expectation that this would resolve these relationships. Instead, the conflict was only magnified. Although tree-building analyses favoured one of the three possible trees, one of the alternative trees actually had one more supporting site (six versus five) and received greater support in spectral and neighbor-net analyses. Simulations suggested that chance alone was unlikely to produce strong support for two of the possible trees and none for the third. Likelihood permutation tests indicated that the concatenated chloroplast sequence data appeared to have experienced recombination. However, recombination between the chloroplast genomes of different species would be highly atypical, and corollary supporting observations, like chloroplast heteroplasmy, are lacking. Wider taxon sampling clarified the composition of the Austral group, but the conflicting signal meant analyses (e.g., morphological evolution, biogeographic) conditional on a well-supported phylogeny could not be performed.

  19. Do asexual polyploid lineages lead short evolutionary lives? A case study from the fern genus Astrolepis.

    Science.gov (United States)

    Beck, James B; Windham, Michael D; Pryer, Kathleen M

    2011-11-01

    A life-history transition to asexuality is typically viewed as leading to a heightened extinction risk, and a number of studies have evaluated this claim by examining the relative ages of asexual versus closely related sexual lineages. Surprisingly, a rigorous assessment of the age of an asexual plant lineage has never been published, although asexuality is extraordinarily common among plants. Here, we estimate the ages of sexual diploids and asexual polyploids in the fern genus Astrolepis using a well-supported plastid phylogeny and a relaxed-clock dating approach. The 50 asexual polyploid samples we included were conservatively estimated to comprise 19 distinct lineages, including a variety of auto- and allopolyploid genomic combinations. All were either the same age or younger than the crown group comprising their maternal sexual-diploid parents based simply on their phylogenetic position. Node ages estimated with the relaxed-clock approach indicated that the average maximum age of asexual lineages was 0.4 My, and individual lineages were on average 7 to 47 times younger than the crown- and total-ages of their sexual parents. Although the confounding association between asexuality and polyploidy precludes definite conclusions regarding the effect of asexuality, our results suggest that asexuality limits evolutionary potential in Astrolepis.

  20. Functional groups of fossil marattialeans: Chemotaxonomic implications for Pennsylvanian tree ferns and pteridophylls

    Science.gov (United States)

    Psenicka, J.; Zodrow, E.L.; Mastalerz, Maria; Bek, J.

    2005-01-01

    Marattialean-fossil foliage, assigned to Pecopteris Brongniart, was an important and widespread floral component in Late Pennsylvanian mires, with phylogenetic affinity to extant marattialean taxa in tropical regions. Marattialean fossil taxonomy is, however, still uncertain. Specimens from the Pilsen limnic Basin, Westphalian D, Czech Republic, represent fertile marattialean foliage of Pecopteris (Asterotheca) nyranensis and Pecopteris (Asterotheca) miltonii, and sterile foliage of Pecopteris aspidioides and Pecopteris polypodioides. Taxonomic parameters for their assignments included cuticle, stomatal morphologies (studied for the first time), and in situ reproductive organs and spores. Chemotaxonomic interpretations hinge on fidelity of preservation of compounds, or molecular fragments thereof, that were synthesized by the once-living plants. This preservation state was possibly due to the thermal history (maximum temperature of 130 ??C) in the Pilsen Basin, acidic preservation conditions, lithology and facies stability. Although subtle, the four pecopterid species are differentiable from one another by combined FTIR characteristics, supporting taxonomy. The ratio of CH2/CH3 is hypothesized to be a chemotaxonomic parameter for Pennsylvanian pteridophylls, both in seed and true ferns that have previously been studied. It will, however, be supplemented by additional biochemical markers. ?? 2004 Elsevier B.V. All rights reserved.

  1. Arbuscular mycorrhiza formation in cordate gametophytes of two ferns, Angiopteris lygodiifolia and Osmunda japonica.

    Science.gov (United States)

    Ogura-Tsujita, Yuki; Sakoda, Aki; Ebihara, Atsushi; Yukawa, Tomohisa; Imaichi, Ryoko

    2013-01-01

    Mycorrhizal symbiosis is common among land plants including pteridophytes (monilophytes and lycophytes). In pteridophytes with diplohaplontic life cycle, mycorrhizal formations were mostly reported for sporophytes, but very few for gametophytes. To clarify the mycorrhizal association of photosynthetic gametophytes, field-collected gametophytes of Angiopteris lygodiifolia (Marattiaceae, n = 52) and Osmunda japonica (Osmundaceae, n = 45) were examined using microscopic and molecular techniques. Collected gametophytes were mostly cut into two pieces. One piece was used for light and scanning microscopic observations, and the other for molecular identification of plant species (chloroplast rbcL sequences) and mycorrhizal fungi (small subunit rDNA sequences). Microscopic observations showed that 96 % (50/52) of Angiopteris and 95 % (41/43) of Osmunda gametophytes contained intracellular hyphae with arbuscules and/or vesicles and fungal colonization was limited to the inner tissue of the thick midribs (cushion). Fungal DNA analyses showed that 92 % (48/52) of Angiopteris and 92 % (35/38) of Osmunda have sequences of arbuscular mycorrhizal fungi, which were highly divergent but all belonged to Glomus group A. These results suggest that A. lygodiifolia and O. japonica gametophytes consistently form arbuscular mycorrhizae. Mycorrhizal formation in wild fern gametophytes, based on large-scale sampling with molecular identification of host plant species, was demonstrated for the first time.

  2. Structures of xyloglucans in primary cell walls of gymnosperms, monilophytes (ferns sensu lato) and lycophytes.

    Science.gov (United States)

    Hsieh, Yves S Y; Harris, Philip J

    2012-07-01

    Little is known about the structures of the xyloglucans in the primary cell walls of vascular plants (tracheophytes) other than angiosperms. Xyloglucan structures were examined in 13 species of gymnosperms, 13 species of monilophytes (ferns sensu lato), and two species of lycophytes. Wall preparations were obtained, extracted with 6 M sodium hydroxide, and the extracts treated with a xyloglucan-specific endo-(1→4)-β-glucanase preparation. The oligosaccharides released were analysed by matrix-assisted laser-desorption ionisation time-of-flight mass spectrometry and by high-performance anion-exchange chromatography. The xyloglucan oligosaccharide profiles from the gymnosperm walls were similar to those from the walls of most eudicotyledons and non-commelinid monocotyledons, indicating that the xyloglucans were fucogalactoxyloglucans, containing the fucosylated units XXFG and XLFG. The xyloglucan oligosaccharide profiles for six of the monilophyte species were similar to those of the gymnosperms, indicating they were also fucogalactoxyloglucans. Phylogenetically, these monilophyte species were from both basal and more derived orders. However, the profiles for the other monilophyte species showed various significant differences, including additional oligosaccharides. In three of the species, these additional oligosaccharides contained arabinosyl residues which were most abundant in the profile of Equisetum hyemale. The two species of lycophytes examined, Selaginella kraussiana and Lycopodium cernuum, had quite different xyloglucan oligosaccharide profiles, but neither were fucogalactoxyloglucans. The S. kraussiana profile had abundant oligosaccharides containing arabinosyl residues. The L. cernuum profile indicated the xyloglucan had a very complex structure.

  3. Adsorption studies of Cu(II) on Boston fern (Nephrolepis exaltata Schott cv. Bostoniensis) leaves

    Science.gov (United States)

    Rao, Rifaqat Ali Khan; Khan, Umra

    2016-02-01

    Adsorption studies were done on Boston fern leaves for the effective removal of Cu(II) ions from aqueous solution. It has been tested for the first time for heavy metal adsorption from aqueous solution. This promising material has shown remarkable adsorption capacity towards Cu(II) ions which confirm its novelty, ease of availability, non-toxic nature, cheapness, etc., and give the main innovation to the present study. The adsorbent was analyzed by FT-IR, SEM and EDS. The effect of pH, contact time, initial metal ion concentration and temperature on the adsorption was investigated using batch process to optimize conditions for maximum adsorption. The adsorption of Cu(II) was maximum (96 %) at pH 4. The experimental data were analyzed by Langmuir, Freundlich and Tempkin isotherms. The kinetic studies of Cu(II)were carried out at room temperature (30 °C) in the concentration range 10-100 mg L-1. The data obtained fitted well with the Langmuir isotherm and pseudo-second-order kinetics model. The maximum adsorption capacity (q m) obtained from Langmuir adsorption isotherm was found to be 27.027 mg g-1 at 30 °C. The process was found to be exothermic and spontaneous in nature. The breakthrough and exhaustive capacities were found to be 12.5 and 37.5 mg g-1, respectively. Desorption studies showed that 93.3 % Cu(II) could be desorbed with 0.1 M HCl by continuous mode.

  4. Anatomical diversity and regressive evolution in trichomanoid filmy ferns (Hymenophyllaceae): a phylogenetic approach.

    Science.gov (United States)

    Dubuisson, Jean-Yves; Hennequin, Sabine; Bary, Sophie; Ebihara, Atsushi; Boucheron-Dubuisson, Elodie

    2011-12-01

    To infer the anatomical evolution of the Hymenophyllaceae (filmy ferns) and to test previously suggested scenarios of regressive evolution, we performed an exhaustive investigation of stem anatomy in the most variable lineage of the family, the trichomanoids, using a representative sampling of 50 species. The evolution of qualitative and quantitative anatomical characters and possibly related growth-forms was analyzed using a maximum likelihood approach. Potential correlations between selected characters were then statistically tested using a phylogenetic comparative method. Our investigations support the anatomical homogeneity of this family at the generic and sub-generic levels. Reduced and sub-collateral/collateral steles likely derived from an ancestral massive protostele, and sub-collateral/collateral types appear to be related to stem thickness reduction and root apparatus regression. These results corroborate the hypothesis of regressive evolution in the lineage, in terms of morphology as well as anatomy. In addition, a heterogeneous cortex, which is derived in the lineage, appears to be related to a colonial strategy and likely to a climbing phenotype. The evolutionary hypotheses proposed in this study lay the ground for further evolutionary analyses that take into account trichomanoid habitats and accurate ecological preferences.

  5. Expression of an insecticidal fern protein in cotton protects against whitefly.

    Science.gov (United States)

    Shukla, Anoop Kumar; Upadhyay, Santosh Kumar; Mishra, Manisha; Saurabh, Sharad; Singh, Rahul; Singh, Harpal; Thakur, Nidhi; Rai, Preeti; Pandey, Paras; Hans, Aradhana L; Srivastava, Subhi; Rajapure, Vikram; Yadav, Sunil Kumar; Singh, Mithlesh Kumar; Kumar, Jitendra; Chandrashekar, K; Verma, Praveen C; Singh, Ajit Pratap; Nair, K N; Bhadauria, Smrati; Wahajuddin, Muhammad; Singh, Sarika; Sharma, Sharad; Omkar; Upadhyay, Ram Sanmukh; Ranade, Shirish A; Tuli, Rakesh; Singh, Pradhyumna Kumar

    2016-10-01

    Whitefly (Bemisia tabaci) damages field crops by sucking sap and transmitting viral diseases. None of the insecticidal proteins used in genetically modified (GM) crop plants to date are effective against whitefly. We report the identification of a protein (Tma12) from an edible fern, Tectaria macrodonta (Fee) C. Chr., that is insecticidal to whitefly (median lethal concentration = 1.49 μg/ml in in vitro feeding assays) and interferes with its life cycle at sublethal doses. Transgenic cotton lines that express Tma12 at ∼0.01% of total soluble leaf protein were resistant to whitefly infestation in contained field trials, with no detectable yield penalty. The transgenic cotton lines were also protected from whitefly-borne cotton leaf curl viral disease. Rats fed Tma12 showed no detectable histological or biochemical changes, and this, together with the predicted absence of allergenic domains in Tma12, indicates that Tma12 might be well suited for deployment in GM crops to control whitefly and the viruses it carries.

  6. Genetic diversity in Isoetes yunguiensis,a rare and endangered endemic fern in China

    Institute of Scientific and Technical Information of China (English)

    CHEN Jinming; Wahiti R.Gituru; LIU Xing; WANG Qingfeng

    2007-01-01

    Isoetes yunguiensis is an endangered and endemic fern in China.Field survey indicated that only one population and no more than 50 individuals occur in the wild.The genetic variation of 46 individuals from the population remaining at Pingha (Guizhou Province,China)was assessed by Random Amplified Polymorphic DNA (RAPD)fingerprinting.Twelve primers were screened from sixty ten-bp arbitrary primers,and a total of 95 DNA fragments were scored.Of these,62.1%were polymorphic loci,which indicated that high level genetic variation existed in the natural population.The accumulation of genetic variation in the history of the taxon and the apparent minimal reduction effect on genetic diversity following destruction of habitat might be responsible for the high level genetic diversity presently remaining in the I.yunguiensis population.However,with the continuing decrease of population size,the genetic diversity will gradually be lost.We suggest that the materials from the extant population should be used for re-establishment of the populations.

  7. Sporangium Exposure and Spore Release in the Peruvian Maidenhair Fern (Adiantum peruvianum, Pteridaceae).

    Science.gov (United States)

    Poppinga, Simon; Haushahn, Tobias; Warnke, Markus; Masselter, Tom; Speck, Thomas

    2015-01-01

    We investigated the different processes involved in spore liberation in the polypod fern Adiantum peruvianum (Pteridaceae). Sporangia are being produced on the undersides of so-called false indusia, which are situated at the abaxial surface of the pinnule margins, and become exposed by a desiccation-induced movement of these pinnule flaps. The complex folding kinematics and functional morphology of false indusia are being described, and we discuss scenarios of movement initiation and passive hydraulic actuation of these structures. High-speed cinematography allowed for analyses of fast sporangium motion and for tracking ejected spores. Separation and liberation of spores from the sporangia are induced by relaxation of the annulus (the 'throwing arm' of the sporangium catapult) and conservation of momentum generated during this process, which leads to sporangium bouncing. The ultra-lightweight spores travel through air with a maximum velocity of ~5 m s(-1), and a launch acceleration of ~6300 g is measured. In some cases, the whole sporangium, or parts of it, together with contained spores break away from the false indusium and are shed as a whole. Also, spores can stick together and form spore clumps. Both findings are discussed in the context of wind dispersal.

  8. Occurrence of brassinosteroids in non-flowering land plants, liverwort, moss, lycophyte and fern.

    Science.gov (United States)

    Yokota, Takao; Ohnishi, Toshiyuki; Shibata, Kyomi; Asahina, Masashi; Nomura, Takahito; Fujita, Tomomichi; Ishizaki, Kimitsune; Kohchi, Takayuki

    2017-04-01

    Endogenous brassinosteroids (BRs) in non-flowering land plants were analyzed. BRs were found in a liverwort (Marchantia polymorpha), a moss (Physcomitrella patens), lycophytes (Selaginella moellendorffii and S. uncinata) and 13 fern species. A biologically active BR, castasterone (CS), was identified in most of these non-flowering plants but another biologically active BR, brassinolide, was not. It may be distinctive that levels of CS in non-flowering plants were orders of magnitude lower than those in flowering plants. 22-Hydroxycampesterol and its metabolites were identified in most of the non-flowering plants suggesting that the biosynthesis of BRs via 22-hydroxylation of campesterol occurs as in flowering plants. Phylogenetic analyses indicated that M. polymorpha, P. patens and S. moellendorffii have cytochrome P450s in the CYP85 clans which harbors BR biosynthesis enzymes, although the P450 profiles are simpler as compared with Arabidopsis and rice. Furthermore, these basal land plants were found to have multiple P450s in the CYP72 clan which harbors enzymes to catabolize BRs. These findings indicate that green plants were able to synthesize and inactivate BRs from the land-transition stage.

  9. Ontogeny and ecology of the filicalean fern Oligocarpia gothanii (Gleicheniaceae) from the Middle Permian of China.

    Science.gov (United States)

    Stevens, Liadan G; Hilton, Jason

    2009-02-01

    Reinvestigation of Oligocarpia gothanii Halle (Gleicheniaceae) from the Permian Period of China has uncovered a rare demonstration of ontogenetic succession in numerous intact plants and has led to emendation of the diagnosis and typification of the species. Reconstruction of the fern's vegetative life cycle shows a small rosette-shaped juvenile plant with immature fronds of pinnae undifferentiated into pinnules. The second stage is a series of leafy shoots increasing in size and complexity and bearing fronds essentially comparable with those of the adult plants. Mature plants have sphenopteroid-type fronds differentiated into vegetative and fertile fronds. Close association of plants on the same bedding plane and the presence of a connecting root network between shoots, show that juvenile plants spread by vegetative propagation using underground stolons. Sedimentological information and co-occurrence with the bryophyte Thallites hallei Lundblad suggests that O. gothanii occupied a wetland habitat and was preserved in an obrution event consistent with flooding of marginal areas in a fluvio-deltaic setting. Although recent studies on Oligocarpia have focused exclusively on reproductive features, new ontogenetic information suggests that plants growing in rapidly changing environments may have been reliant on vegetative propagation and would not have needed to reach sexual maturity for successful reproduction.

  10. The potential of the fresh-water fern Azolla in aquatic farming systems

    Science.gov (United States)

    Bijl, Peter K.; Werf, vd, Adrie; Schluepmann, Henriette; Reichart, Gert-Jan; Brouwer, Paul; Nierop, Klaas G. J.; Hellgardt, Klaus; Brinkhuis, Henk

    2014-05-01

    With aquatic farming systems a new avenue in agriculture is explored, in which the competition with conventional arable land is avoided. The aquatic, ubiquitous, floating fern Azolla is not yet widely explored as potential crop in such farming systems, despite its high potential because it grows in many natural systems under low-light intensities, has an enormous annual yield, and has special biomass qualities for applications in food, feed and specialty chemical industries. But, what makes Azolla particularly interesting as cost-effective crop is its capability to take up atmospheric nitrogen through symbiosis with nitrogen-fixing bacteria Anabaena azollae. This makes Azolla independent of nitrogen fertilization. In order to explore the potential of Azolla as a crop for a suite of applications, we have assembled a team of expertise: AZOFAST, consisting of agricultural engineers, plant physiologists, chemical engineers and organic chemists. Our growth experiments reveal high annual production yields with constant harvest. We are developing a germination and spore collecting/preservation protocol as a first step to domestication. Finally we have explored the biomass quality of different species of extant Azolla. We performed organic chemical analyses on lipid and tannin extracts, and quantified yields of specific compounds within these fractions. In our presentation we will present some of our results to show the potential of Azolla as a new, sustainable aquatic crop serving all kinds of industrial streams from protein feed to platform chemicals.

  11. Comparison of two ferns (Adiantum capillus-veneris Linn. and Microsorium punctatum (Linn.) Copel) for their Cr accumulation potential and antioxidant responses.

    Science.gov (United States)

    Sinam, Geetgovind; Behera, Sandip K; Mishra, Rohit K; Sinha, Sarita; Mallick, Shekhar; Khare, P B

    2012-08-01

    Study was undertaken to compare Cr accumulation in two ferns (Adiantum capillus-veneris Linn. and Microsorium punctatum (Linn.) Copel) and the role of antioxidants were also investigated towards metal tolerance in order to assess the use of ferns in phytomediation/ phytostabilization. Different concentrations (0, 50, 100, 150 microg g(-1) dw) of Cr were added to fern planted in pot containing 1 kg soil. In both the ferns, Cr accumulation increased with increase in metal concentration and maximum accumulation of 800.5 microg g(-1) (fronds) and 1457.4 microg g(-1) (roots) in M. punctatum and 660.8 microg g(-1) (fronds) and 1259.6 microg g(-1) (roots) in A. capillus-veneris was recorded. The increase in the levels of malondialdehyde, antioxidants and antioxidant enzymes (superoxide dismutase, glutathione peroxidase) in A. capillus-veneris was less pronounced than M. punctatum under Cr exposure as compared to their respective controls. In view of less decrease in chlorophyll content and antioxidants along with higher accumulation of Cr in the fronds M. punctatum, is indicative of its higher tolerance towards Cr. However, bioaccumulation factor (concentration of Cr in fronds/concentration of Cr in the soil) of both the ferns was recorded > 1 which qualifies the plants as potential Cr hyperaccumulator and suitable for phytoremediaton.

  12. “Barba Azul”: de Perrault a Wenceslao Fernández Flórez / “Bluebeard”: from Perrault to Wenceslao Fernández Flórez

    OpenAIRE

    Fermín Ezpeleta Aguilar

    2012-01-01

    Resumen: En este artículo se pone de manifiesto la amalgama de datos de historia real y de elementos míticos con los que se conforma literariamente el motivo literario de Barba Azul a lo largo del tiempo. Se deslindan, sobre todo, las dos versiones más importantes que hacen del motivo un cuento popular: la de Perrault y la de los hermanos Grimm, para analizar a continuación la reescritura que hace Wenceslao Fernández Flórez en su narración El secreto de Barba Azul (1923). Esta novela de form...

  13. Determination of thermal stability of specific biomarker lipids of the freshwater fern Azolla through hydrous pyrolysis

    Science.gov (United States)

    Sap, Merel; Speelman, Eveline N.; Lewan, Michael D.; Sinninghe Damsté, Jaap S.; Reichart, Gert-Jan

    2010-05-01

    Enormous blooms of the free-floating freshwater fern Azolla occurred within the Arctic Basin during an extended period of ~1.2 Ma during the middle Eocene (Brinkhuis et al. 2006; Speelman et al., GB, 2009). The sustained growth of Azolla, currently ranking among the fastest growing plants on Earth, in a major anoxic basin may have substantially contributed to decreasing atmospheric CO2 levels by burial of Azolla-derived organic matter. Speelman et al. (OG, 2009) reported biomarkers for Azolla (1,w20 C32 - C36 diols, structurally related C29 ω20,ω21 diols, C29 1,20,21 triols, C29 dihydroxy fatty acids as well as a series of wax esters containing these mono- and dihydroxy lipids), which can be used to reconstruct palaeo-environmental conditions. Here we assess the thermal stability of these compounds, to extend their biomarker potential. We specifically focused on the thermal stability of the Azolla biomarkers using hydrous pyrolysis in order to determine which burial conditions allow reconstruction of past occurrences of Azolla. In addition, hydrous pyrolysis was also performed on samples from the Eocene Arctic Ocean (ACEX core), to test if and how the biomarkers change under higher temperatures and pressures in situ. During hydrous pyrolysis, the biomass was heated under high pressure at temperatures ranging between 220 and 365°C for 72 hours. Four experiments were also run using different durations to explore the kinetics of biomarker degradation at specific temperatures. First results indicate that the Azolla specific diols are still present at 220°C, while the corresponding wax esters are already absent. At 300°C all Azolla specific biomarkers are destroyed. More specific determination of the different biomarkers' stability and kinetics would potentially allow the reconstruction of the temperature and pressure history of Azolla deposits. Literature: • Brinkhuis, H., Schouten, S., Collinson, M. E., Sluijs, A., Sinninghe Damste, J. S., Dickens, G. R., Huber

  14. Explotación de peces asociada a la pesquería artesanal de langosta de Juan Fernández (Jasus frontalis

    Directory of Open Access Journals (Sweden)

    Mauricio Ahumada

    2014-03-01

    Full Text Available Para contribuir al conocimiento de la explotación de peces asociada a la pesquería de langosta de Juan Fernández, se monitorearon 157 salidas de pesca durante la temporada 2010-2011. Se capturaron 10.462 ejemplares correspondientes a 19 especies de peces, tres de las cuales concentraron el 94% de la captura en número: jurel de Juan Fernández (Pseudocaranx chilensis (45%, breca (Nemadactylus gayi (41% y anguila morena (Gymnothoraxporphyreus (8%. Las capturas totales estimadas fueron 40, 24 y 13 ton de breca, jurel de Juan Fernández y anguila morena, respectivamente. El 97% de los ejemplares de peces capturados fueron utilizados como carnada de peces o langosta.

  15. Chemotaxonomy for naturally macerated tree-fern cuticles (Medullosales and Marattiales), Carboniferous Sydney and Mabou Sub-Basins, Nova Scotia, Canada

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2001-01-01

    Naturally macerated cuticles (NMC) and one synangium, representing medullosalean and marattialean tree-fern species, from two Carboniferous coalfields in Nova Scotia, Canada, are investigated. The samples were analyzed by infrared spectroscopy (FTIR), and by pyrolysis-gas chromatograph/mass spectrometry (py-Gc/Ms) techniques in search for chemical signatures that would help in developing a chemotaxonomic classification of Carboniferous fern species, assuming genetically dependent make-up of cuticles. FTIR-derived CH2/CH3 ratios, in conjunction with contributions from carboxyl groups, demonstrated a better potential for discriminating between medullosalean genera and species than molecular signatures obtained by py-Gc/Ms. However, the latter provided better data for differentiating medullosalean from marattialean tree ferns as a group. Changes in the chemical make-up of naturally macerated cuticles due to sample preparation are discussed. ?? 2001 Elsevier Science B.V. All rights reserved.

  16. New cyathealean tree ferns from the Cretaceous of South Africa: Natalipteris wildei gen. et sp. nov. and Kwazulupteris schaarschmidtii gen. et sp. nov.

    Science.gov (United States)

    Vera, Ezequiel Ignacio; Herbst, Rafael

    2015-01-01

    Two new genera and species of permineralized tree ferns, Natalipteris wildei and Kwazulupteris schaarschmidtii, are defined and described in detail. Natalipteris wildei is a solenostelic stem without well-developed sclerenchyma sheaths in their vascular strands, and has a single vascular strand in the petiole bases, which are somewhat similar to the one present in Cibotium and Nishidacaulis. On the other hand, K. schaarschmidtii is a dictyostelic fern, with petiole bases with fused adaxial arcs and a single isolated meristele in the petiolar pith. Both taxa present features that preclude their placement in the recognized families of Cyatheales, but may be referred to the "core tree ferns" clade. Fossil specimens were found in the Senckenberg Forschungsinstitut Palaeobotanical Collection and, although they lack precise stratigraphic provenance, it is suggested that they were collected from the Mzinene Formation (Albian-Turonian).

  17. Intrathermocline eddies at the Juan Fernández Archipelago, southeastern Pacific

    Directory of Open Access Journals (Sweden)

    Isabel Andrade

    2014-10-01

    Full Text Available Regional Ocean Modeling System (ROMS results, combined with chlorophyll-α (Chl-α and satellite altimetry information as well as information from oceanographic cruises were analyzed to identify interactions between intrathermocline eddies (ITEs and the Juan Fernández Archipelago (JFA, and discuss their potential impact on surface Chl-α concentrations. The JFA is located off the coast of central Chile (33°S, and is composed of three main islands: Robinson Crusoe (RC, Alejandro Selkirk (AS and Santa Clara (SC. Results indicate that the surface and subsurface anticyclonic eddies that interact with the JFA are formed primarily within the coastal transition zone between 33° and 39°S. ITEs are present within the JFA region with a semiannual frequency, mainly during the austral autumn, and have a weak surface expression in relation to the adjacent surface eddies, with a slow displacement (1.16 to 1.4 km d-1 in a northwest direction and a coherent structure for periods of ≥ 1 year. During the ITEs' interaction with RC-SC islands and an adjacent seamount, a slight (prominent thermocline deflection of the upper limit (lower was observed. The horizontal extent (~70-100 km was greater than the internal Rossby deformation radius and the average vertical extent was ~400 m. The interaction between the weak surface expression of ITEs, identified with satellite altimetry, and the JFA persisted during autumn for nine weeks until reaching the winter period. Approximately one month after the beginning of the interaction between ITEs and the islands, increases in surface Chl-α associated with the eddy were observed, with values up to three times higher than adjacent oceanic waters.

  18. Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

    Directory of Open Access Journals (Sweden)

    Lim Yau Y

    2010-04-01

    Full Text Available Abstract Background Blechnum orientale Linn. (Blechnaceae is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of Blechnum orientale Linn. Methods Five solvent fractions were obtained from the methanol extract of B. orientale through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted. Results The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC50 8.6-13.0 μg/ml and cytotoxic activity towards human colon cancer cell HT-29 (IC50 27.5-42.8 μg/ml. The three extracts were also effective against all Gram-positive bacteria tested: Bacillus cereus, Micrococcus luteus, methicillin-susceptible Staphylococcus aureus (MSSA, methicillin-resistant Staphylococcus aureus (MRSA and Stapylococcus epidermidis(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml. Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g. Conclusions The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA

  19. The potential of the aquatic water fern Azolla within a biobased economy

    Science.gov (United States)

    Nierop, Klaas G. J.; Jongerius, Anna L.; Bijl, Peter K.; Bruijnincx, Pieter C. A.; Klein Gebbink, Robertus J. M.; Reichart, Gert-Jan

    2014-05-01

    Azolla is a free-floating freshwater fern capable of fixing atmospheric carbon dioxide and nitrogen, the latter of which through its symbiosis with the cyanobacteria Anabaena azollae. It is currently ranked among the fastest growing plants on Earth and occurs in both tropical and temperate freshwater ecosystems. Therefore, it is non-directly competitive with food crops. In addition, Azolla does not require inorganic fertilizers, which makes it a potential and unique source of biomass for the sustainable production of fuels and chemicals that are currently derived from fossil (fuel) sources. The biochemical composition of Azolla allows the production of biofuel or biobased chemicals that are of interest to the chemical industry. Of Azolla, two extractable groups of compounds are of particular interest, i.e. the polyphenols (condensed tannins and ester-bound caffeic acid) and the lipids. The antioxidant property of polyphenols and their application to the treatment of cancer, diabetes and cardiovascular diseases has further contributed to the growth of the polyphenol market. In addition, they can be chemically transformed into aromatic platform and specialty chemicals. The composition of the lipid fraction of Azolla is characterized by highly specific compounds consisting of C26-C36 carbon chains all bearing a ω20-hydroxy group. Such compounds produce an oil fraction upon hydrous pyrolysis, or, alternatively, are well suited to be converted to e.g. various specialty chemicals that are hardly available from both natural sources. Indeed, upon chemical conversion these lipids may yield components for fuels, plastics, cosmetics, and lubricants. Another group of interesting compounds within the lipid group are the polyunsaturated fatty acids (PUFAs). The demand for PUFAs has witnessed a significant increase over the last three years, particularly due to their benefits as cholesterol lowering agents. Here we will present some of the thermal and chemical conversions of the

  20. Phytochemistry of the fossilized-cuticle frond Macroneuropteris macrophylla (Pennsylvanian seed fern, Canada)

    Science.gov (United States)

    Zodrow, E.L.; D'Angelo, J. A.; Mastalerz, Maria; Cleal, C.J.; Keefe, D.

    2010-01-01

    In Canada's Sydney Coalfield, specimens of the extinct Carboniferous seed fern Macroneuropteris macrophylla (Brongniart) invariably show preservation stages intermediate between compression and fossilized-cuticle, even concerning a single pinnule. In this interdisciplinary approach, we study a ca. 300 to 350 mm long fossilized-cuticle-preserved frond section of M. macrophylla (Brongniart) that represents about one third of the length of a frond that was originally 1 m long. Size and preservation allow us to study the phytochemistry of the cuticle biomacropolymers over the length of the frond to assess what impact, if any, results would have on Carboniferous palaeophytochemotaxonomy. For comparison, the phytochemistry of compressions with their extracted cuticles from the same species and the same sample locality is also investigated. We use solid- and liquid-state, semi-quantitative Fourier transform infrared spectroscopy (FTIR) for the chemical characterization of the frond.Based on our results, we infer an essentially uniform phytochemistry over the fossilized-cuticle frond, suggesting that only a single pinnule needs to be analyzed to get an overall phytochemical picture of the frond, which has been our long-time working hypothesis. We distinguish between phytochemistry and cutinization. The latter is much less pronounced above than below the frond dichotomy, and we suggest a palaeoecological cause, rather than differing pathways of organic matter transformation. Moreover, cuticles below and above the frond dichotomy have essentially the same epidermal pattern, but those from below have features that may have been an adaptation to prevent stomatal flooding during the tropical, rainy season.This study suggests that chemically the fossilized-cuticle is more similar to the compression than to the cuticle obtained from that compression of the same species which invites reevaluation of the classical compression concept. ?? 2010 Elsevier B.V.

  1. Phytochemistry of the fossilized-cuticle frond Macroneuropteris macrophylla (Pennsylvanian seed fern, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia, B1P 6L2 (Canada); D' Angelo, Jose A. [IANIGLA, CCT-CONICET-Mendoza, Avda. Ruiz Leal s/n Parque Gral. San Martin (5500) Mendoza (Argentina); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, IN, 47405-2208 (United States); Cleal, Christopher J. [Department of Biodiversity and Systematic Biology, National Museum of Wales, Cathays Park, Cardiff, CF10 3NP (United Kingdom); Keefe, Dale [Molecular Spectroscopy Research Laboratory, Department of Chemistry, Cape Breton University, Sydney, Nova Scotia (Canada)

    2010-11-01

    In Canada's Sydney Coalfield, specimens of the extinct Carboniferous seed fern Macroneuropteris macrophylla (Brongniart) invariably show preservation stages intermediate between compression and fossilized-cuticle, even concerning a single pinnule. In this interdisciplinary approach, we study a ca. 300 to 350 mm long fossilized-cuticle-preserved frond section of M. macrophylla (Brongniart) that represents about one third of the length of a frond that was originally 1 m long. Size and preservation allow us to study the phytochemistry of the cuticle biomacropolymers over the length of the frond to assess what impact, if any, results would have on Carboniferous palaeophytochemotaxonomy. For comparison, the phytochemistry of compressions with their extracted cuticles from the same species and the same sample locality is also investigated. We use solid- and liquid-state, semi-quantitative Fourier transform infrared spectroscopy (FTIR) for the chemical characterization of the frond. Based on our results, we infer an essentially uniform phytochemistry over the fossilized-cuticle frond, suggesting that only a single pinnule needs to be analyzed to get an overall phytochemical picture of the frond, which has been our long-time working hypothesis. We distinguish between phytochemistry and cutinization. The latter is much less pronounced above than below the frond dichotomy, and we suggest a palaeoecological cause, rather than differing pathways of organic matter transformation. Moreover, cuticles below and above the frond dichotomy have essentially the same epidermal pattern, but those from below have features that may have been an adaptation to prevent stomatal flooding during the tropical, rainy season. This study suggests that chemically the fossilized-cuticle is more similar to the compression than to the cuticle obtained from that compression of the same species which invites reevaluation of the classical compression concept. (author)

  2. La colección Fernández Rivero de fotografía antigua

    Directory of Open Access Journals (Sweden)

    García Ballesteros, María Teresa

    2015-02-01

    Full Text Available La Colección Fernández Rivero de fotografía antigua es una colección de objetos fotográficos originales de más de 45000 piezas de diversa tipología. La CFRivero ha seguido para su formación un criterio historicista de manera que pudiese cubrir fines museísticos y didácticos. Alrededor de dos tercios de sus piezas son del siglo XIX, de las cuales la mayor parte podrían describirse como parte fundamental del patrimonio fotográfico español de este periodo. Es por tanto una colección fundamentalmente de fotografía histórica española, aunque contiene también notables ejemplos representativos de fotografía de Francia, Reino Unido y otros países, además de dos secciones especiales: fotografía estereoscópica y fotografía relacionada con Málaga y su provincia. Se complementa con máquinas y otros objetos fotográficos así como con una nutrida biblioteca antigua y contemporánea. Los propietarios vienen desarrollando una amplia labor de difusión e investigación del fenómeno fotográfico, centrado especialmente en el siglo XIX. Para ello se han publicado libros y artículos, celebrado exposiciones, conferencias y talleres, así como una amplia y activa difusión a través de Internet.

  3. Potential of mosquito fern (Azolla caroliniana Willd.) plants as a biofilter for cadmium removal from waste water

    Energy Technology Data Exchange (ETDEWEB)

    Sajwam, K.S.; Ornes, W.H. [Savannah State College, GA (United States)]|[Univ. of South Carolina, Aiken, SC (United States)

    1995-12-31

    The aquatic vascular Mosquito Fern (Azolla Caroliania Willd.) was investigated as a potential biological filter for removal of Cd from waste water. Mosquito Fern plants were grown in and harvested weekly from 0.10 M Hoagland nutrient solutions containing 0.01, 0.04, and 1.03 {mu}g Cd mL{sup -1} or 0.50 M Hoagland nutrient solutions containing 0.02, 1.0, and 9.14,{mu}g Cd mL{sup -1}. Dry weights of plants significantly increased when exposed to all three Cd concentrations in 0. 10 M Hoagland solution through week three then decreased thereafter. However, in plants exposed to Cd treatments in 0.50 M Hoagland solution, dry weights increased through week one and decreased thereafter. Tissue Cd concentrations in plants grown in 0.10 M Hoagland solution increased during the first two weeks followed by decreases in week 3 and 4. However, tissue Cd increased through week 3 in plants grown in 0.50 M Hoagland solutions. Cadmium exposure to plants grown in 0.10 M Hoagland solution seemed to increase the tissue P concentrations in plants exposed to the lowest concentration of Cd. Tissue P in both control and treated plants in 0.50 M Hoagland solution seemed to increase over time with exception of the medium level (1 {mu}g Cd mL{sup -1}). These results suggest that Mosquito Fern would be useful for absorbing Cd from nutrient-rich water when the solution concentration was in the range of as low as 0.01 and as high as 9.14 {mu}g Cd mL{sup -1}. However, the harvest regime would have to be every one or two weeks to sustain plant vigor and realize maximum uptake of Cd from solution.

  4. 15 June 2009 - President of the Argentine Nation C. Fernández visiting ATLAS experimental area.

    CERN Multimedia

    Maximilien Brice

    2009-01-01

    Tirage 1:President of the Argentine Nation, C. Fernández and Minister of Science, Technology and Innovative Production,L. Barañao Tirage 2-8:Arrival greetings Tirage 9-12:Introduction to CERN's activities by Director-General, R. Heuer Tirage 13-15:Signature of the guest book Tirage 16-25:M. Benedetti,R. Heuer and L.Barañao sit for the signature of the Agreement Tirage 26-33: Meeting with Argentinian scientists at CERN

  5. La escritora Ana de Zayas y el obispo poblano Manuel Fernández de Santa Cruz

    OpenAIRE

    Zayas, Concepción

    2001-01-01

    Estudio de caso sobre la relación entre el obispo de la diócesis angelopolitana, don Manuel Fernández de Santa Cruz, y doña Ana de Zayas, escritora que la Inquisición novohispana procesó por alumbrada de 1694 a 1700. Este trabajo analiza principalmente la intervención del prelado a favor de esta mujer, lo cual impidió que ella fuera condenada por el Santo Oficio de México. El artículo se basa en fuentes mexicanas y españolas.

  6. La escritora Ana de Zayas y el obispo poblano Manuel Fernández de Santa Cruz

    Directory of Open Access Journals (Sweden)

    Zayas, Concepción

    2001-06-01

    Full Text Available Estudio de caso sobre la relación entre el obispo de la diócesis angelopolitana, don Manuel Fernández de Santa Cruz, y doña Ana de Zayas, escritora que la Inquisición novohispana procesó por alumbrada de 1694 a 1700. Este trabajo analiza principalmente la intervención del prelado a favor de esta mujer, lo cual impidió que ella fuera condenada por el Santo Oficio de México. El artículo se basa en fuentes mexicanas y españolas.

  7. Developing and Deploying an XML-based Learning Content Management System at the FernUniversität Hagen

    Directory of Open Access Journals (Sweden)

    Gerd Steinkamp

    2005-02-01

    Full Text Available This paper is a report about the FuXML project carried out at the FernUniversität Hagen. FuXML is a Learning Content Management System (LCMS aimed at providing a practical and efficient solution for the issues attributed to authoring, maintenance, production and distribution of online and offline distance learning material. The paper presents the environment for which the system was conceived and describes the technical realisation. We discuss the reasons for specific implementation decisions and also address the integration of the system within the organisational and technical infrastructure of the university.

  8. Figurations of Islandness in Argentine Culture and Literature: Macedonio Fernández, Leopoldo Marechal, and César Aira

    Directory of Open Access Journals (Sweden)

    Norman Cheadle

    2009-11-01

    Full Text Available This article explores islandness in the River Plate imaginary. Two modern foundational “island texts” – Thomas More’s Utopia and Daniel Defoe’s Robinson Crusoe – have exerted a formative influence on the Spanish-American colonial imagination, an influence inflected by the particular historical experience of the River Plate region and its dominant city, Buenos Aires. The figuration of islandness is examined in three twentieth-century Argentine novels by Macedonio Fernández, Leopoldo Marechal, and César Aira. The article finds both continuity and evolution in the images of islandness in these novels.

  9. Relación entre la obra de José Antonio Fernández Ordóñez y de Eduardo Chillida Juantegui

    OpenAIRE

    Collell Mundet, Guillem

    2005-01-01

    Las obras de Eduardo Chillida muestran oficios artesanales, oficios que tratan el hierro, la madera, la ferralla, la piedra y el hormigón. Es en este último material dónde José Antonio Fernández Ordóñez, amigo íntimo de Eduardo Chillida e ingeniero de caminos, fue partícipe de la creación de todas sus esculturas de hormigón, principal motivo de esta tesina. Fernández Ordóñez le proporcionaba a Chillida la destreza técnica y conceptual sobre el material hasta entonces inutilizado en la escultu...

  10. “Barba Azul”: de Perrault a Wenceslao Fernández Flórez / “Bluebeard”: from Perrault to Wenceslao Fernández Flórez

    Directory of Open Access Journals (Sweden)

    Fermín Ezpeleta Aguilar

    2012-01-01

    Full Text Available Resumen: En este artículo se pone de manifiesto la amalgama de datos de historia real y de elementos míticos con los que se conforma literariamente el motivo literario de Barba Azul a lo largo del tiempo. Se deslindan, sobre todo, las dos versiones más importantes que hacen del motivo un cuento popular: la de Perrault y la de los hermanos Grimm, para analizar a continuación la reescritura que hace Wenceslao Fernández Flórez en su narración El secreto de Barba Azul (1923. Esta novela de formación tan representativa del autor se pone en conexión con el resto de su producción literaria y se comentan en ella aquellos aspectos temáticos y estructurales que inciden en la cuestión educativa, señalando intertextualidades con las versiones del cuento popular.Abstract: This article shows the historical data of real and mythical elements about Bluebeard motif over time. We identify in particular the two most important versions which make the topic a folktale: Perrault and Grimm Brothers, to discuss then the rewriting by Wenceslao Fernández Flórez, El secreto de Barba Azul (1923. This Bildungsroman connects strongly with the rest of his literature. We comment on the thematic and structural aspects that are closely related to education, noting intertextualities with versions of the folktale.

  11. Hasta siempre Profesor Manuel Fernández: Palabras en homenaje al ex Decano de la Facultad de Arquitectura y Urbanismo Dr. Arqto. Manuel Fernández Hechenleitner (1946- 2003. / Farewell, Professor Manuel Fernandez: Words in tribute to the former - Dean of the Faculty of Architecture and Planning Dr. Arqto. Manuel Fernández Hechenleitner (1946 - 2003.

    Directory of Open Access Journals (Sweden)

    Javier de Cárdenas

    2003-06-01

    Full Text Available Académicos, ex alumnos y amigos de la Facultad de Arquitectura y Urbanismo de la Universidad de Chile, recuerdan la personalidad del Dr. Arquitecto Manuel Fernández Hechenleitner (1946-2003, ex Decano de la F.A.U., con motivo de su fallecimiento./Academics, ex - students and friends of the School of Architecture and Urbanism of the University of Chile, remember the personality of Dr. Manuel Fernandez Hechenleitner Architect (1946-2003, ex - Dean of the FAU, on the occasion of his death.

  12. Las miradas de Gonzalo Fernández de Oviedo sobre la naturaleza del Nuevo Mundo = As visões de Gonzalo Fernández de Oviedo sobre a Natureza do Novo Mundo = Gonzalo Fernández de Oviedo’s Glances at New World’s Nature

    Directory of Open Access Journals (Sweden)

    Baraibar, Álvaro

    2014-01-01

    Full Text Available O presente estudo se aproxima da perspectiva que Gonzalo Fernández de Oviedo, primeiro cronista das Índias, lançou sobre a Natureza do Novo Mundo. Em Oviedo encontramos diferentes olhares que falam de inquietudes, intenções e interesses inclusive contraditórios e que variam segundo o tema tratado e seu contexto. Todas essas perspectivas nos ajudam a conhecer melhor o discurso que está sendo construído na primeira metade do século XVI sobre a América e a natureza americana

  13. Complex rheological properties of a water-soluble extract from the fronds of the black tree fern, Cyathea medullaris.

    Science.gov (United States)

    Goh, Kelvin K T; Matia-Merino, Lara; Hall, Christopher E; Moughan, Paul J; Singh, Harjinder

    2007-11-01

    A water-soluble extract was obtained from the fronds of a New Zealand native black tree fern (Cyathea medullaris or Mamaku in Māori). The extract exhibited complex rheological behavior. Newtonian, shear-thinning, shear-thickening, thixotropic, antithixotropic, and viscoelastic behaviors were observed depending on polymer concentration, shear rate, and shear history. The extract also displayed rod-climbing and self-siphoning properties typical of viscoelastic fluids. Such complex rheological properties have been reported in synthetic or chemically modified polymers but are less frequent in unmodified biopolymers. Although Mamaku extract obtained from the pith of the fern has been traditionally used by the Māori in New Zealand for treating wounds and diarrhea among other ailments, this material has never been characterized before. This study reports on the chemical composition of the extract and on its viscoelastic properties through rotational and oscillatory rheological measurements. Explanations of the mechanism behind the rheological properties were based on transient network models for associating polymers.

  14. Genetic diversity in the Homosporous Fern Ophioglossum vulgatum (Ophioglossaceae) from South Korea: inference of mating system and population history.

    Science.gov (United States)

    Chung, Mi Yoon; López-Pujol, Jordi; Chung, Jae Min; Moon, Myung-Ok; Chung, Myong Gi

    2013-03-01

    It is generally believed that the members of Ophioglossaceae have subterranean, potentially bisexual gametophytes, which favor intragametophytic selfing. In Ophioglossaceae, previous allozyme studies revealed substantial inbreeding within Botrychium species and Mankyua chejuense. However, little is known about the mating system in species of the genus Ophioglossum. Molecular marker analyses can provide insights into the relative occurrence of selfing versus cross-fertilization in the species of Ophioglossum. We investigated allozyme variation in 8 Korean populations of the homosporous fern Ophioglossum vulgatum to infer its mating system and to get some insight into the population-establishment history in South Korea. We detected homozygous genotypes for alternative alleles at several loci, which suggest the occurrence of intragametophytic self-fertilization. Populations harbor low within-population variation (% P = 7.2, A = 1.08, and H (e) = 0.026) and a high among-population differentiation (F (ST) = 0.733). This, together with the finding that alternative alleles were fixed at several loci, suggests that the number and size of populations of O. vulgatum might have been severely reduced during the last glaciation (i.e., due to its in situ persistence in small, isolated refugia). The combined effects of severe random genetic drift and high rates of intragametophytic selfing are likely responsible for the genetic structure displayed by this homosporous fern. Its low levels of genetic diversity in South Korea justify the implementation of some conservation measures to ensure its long-term preservation.

  15. Four tropical, closely related fern species belonging to the genus Adiantum L. are genetically distinct as revealed by ISSR fingerprinting.

    Science.gov (United States)

    Korpelainen, Helena; de Britto, John; Doublet, Jérémy; Pravin, Sahaya

    2005-11-01

    The level and pattern of genetic variation was analyzed in four species of the fern genus Adiantum L., A. hispidulum Sw., A. incisum Forrsk., A. raddianum C.Presl, and A. zollingeri Mett. ex Kuhn, originating from South India, using the ISSR fingerprinting method. The populations of Adiantum possessed a considerable level of genetic variation, the diversity indices ranging from 0.284 to 0.464. Only 12% of the ISSR markers found were restricted to one species only, and 54% were detected in all four species. The analysis of molecular variance revealed that 71.1% of variation was present within populations. The proportion of variation detected among species was only 18.5% while the proportion of variation among populations within species equalled 10.4%. Despite the low level of intrageneric differentiation, the discriminant analysis and clustering of genetic distances indicated that the four Adiantum species are genetically distinct. The F(ST) values calculated for the species were low, varying from 0.089 to 0.179. No linkage disequilibrium was detected between the loci. Such low level of differentiation among populations and the presence of linkage equilibrium reflect that the life history of Adiantum ferns apparently involves common or relatively common sexuality, effective wind-dispersal of spores and outcrossing.

  16. Arbuscular mycorrhizal colonization in field-collected terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns (Osmundaceae, Gleicheniaceae, Plagiogyriaceae, Cyatheaceae).

    Science.gov (United States)

    Ogura-Tsujita, Yuki; Hirayama, Yumiko; Sakoda, Aki; Suzuki, Ayako; Ebihara, Atsushi; Morita, Nana; Imaichi, Ryoko

    2016-02-01

    To determine the mycorrhizal status of pteridophyte gametophytes in diverse taxa, the mycorrhizal colonization of wild gametophytes was investigated in terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns, i.e., one species of Osmundaceae (Osmunda banksiifolia), two species of Gleicheniaceae (Diplopterygium glaucum, Dicranopteris linearis), and four species of Cyatheales including tree ferns (Plagiogyriaceae: Plagiogyria japonica, Plagiogyria euphlebia; Cyatheaceae: Cyathea podophylla, Cyathea lepifera). Microscopic observations revealed that 58 to 97% of gametophytes in all species were colonized with arbuscular mycorrhizal (AM) fungi. Fungal colonization was limited to the multilayered midrib (cushion) tissue in all gametophytes examined. Molecular identification using fungal SSU rDNA sequences indicated that the AM fungi in gametophytes primarily belonged to the Glomeraceae, but also included the Claroideoglomeraceae, Gigasporaceae, Acaulosporaceae, and Archaeosporales. This study provides the first evidence for AM fungal colonization of wild gametophytes in the Plagiogyriaceae and Cyatheaceae. Taxonomically divergent photosynthetic gametophytes are similarly colonized by AM fungi, suggesting that mycorrhizal associations with AM fungi could widely occur in terrestrial pteridophyte gametophytes.

  17. Comparison between WorldView-2 and SPOT-5 images in mapping the bracken fern using the random forest algorithm

    Science.gov (United States)

    Odindi, John; Adam, Elhadi; Ngubane, Zinhle; Mutanga, Onisimo; Slotow, Rob

    2014-01-01

    Plant species invasion is known to be a major threat to socioeconomic and ecological systems. Due to high cost and limited extents of urban green spaces, high mapping accuracy is necessary to optimize the management of such spaces. We compare the performance of the new-generation WorldView-2 (WV-2) and SPOT-5 images in mapping the bracken fern [Pteridium aquilinum (L) kuhn] in a conserved urban landscape. Using the random forest algorithm, grid-search approaches based on out-of-bag estimate error were used to determine the optimal ntree and mtry combinations. The variable importance and backward feature elimination techniques were further used to determine the influence of the image bands on mapping accuracy. Additionally, the value of the commonly used vegetation indices in enhancing the classification accuracy was tested on the better performing image data. Results show that the performance of the new WV-2 bands was better than that of the traditional bands. Overall classification accuracies of 84.72 and 72.22% were achieved for the WV-2 and SPOT images, respectively. Use of selected indices from the WV-2 bands increased the overall classification accuracy to 91.67%. The findings in this study show the suitability of the new generation in mapping the bracken fern within the often vulnerable urban natural vegetation cover types.

  18. Biosynthesis of lead nanoparticles by the aquatic water fern, Salvinia minima Baker, when exposed to high lead concentration.

    Science.gov (United States)

    Castro-Longoria, E; Trejo-Guillén, K; Vilchis-Nestor, A R; Avalos-Borja, M; Andrade-Canto, S B; Leal-Alvarado, D A; Santamaría, J M

    2014-02-01

    Salvinia minima Baker is a small floating aquatic fern that is efficient for the removal and storage of heavy metals such as lead and cadmium. In this study, we report that lead removal by S. minima causes large accumulation of lead inside the cells in the form of nanoparticles (PbNPs). The accumulation pattern of lead was analyzed in both, submerged root-like modified fronds (here named "roots"), and in its aerial leaf-like fronds ("leaves"). Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) confirmed the biosynthesis of PbNPs by the plant. In both, roots and leaves, PbNPs were found to accumulate almost exclusively at the cell wall and closely associated to the cell membrane. Two types of PbNPs shapes were found in cells of both tissues, those associated to the cell wall were quasi-spherical with 17.2±4.2 nm of diameter, while those associated to the cell membrane/cytoplasm were elongated. Elongated particles were 53.7±29.6 nm in length and 11.1±2.4 nm wide. Infrared spectroscopy (IR) results indicate that cellulose, lignin and pectin are the major components that may be acting as the reducing agents for lead ions; these findings strongly suggest the potential use of this fern to further explore the bio-assisted synthesis of heavy metal nanostructures.

  19. Emission of methyl chloride from a fern growing in subtropical, temperate, and cool-temperate climate zones

    Science.gov (United States)

    Yokouchi, Yoko; Takenaka, Akio; Miyazaki, Yuzo; Kawamura, Kimitaka; Hiura, Tsutom

    2015-06-01

    Tropical and subtropical forests are believed to be the largest source of methyl chloride (CH3Cl), which is a natural stratospheric ozone destroyer. However, very little is known about what controls the rate of emission from these forests or why biogenic CH3Cl emission is concentrated in the tropics and subtropics. In this study, we investigated the seasonal and spatial variations of the rate of CH3Cl emission from the fern Osmunda japonica, which has a broad distribution covering the subtropical, temperate, and subboreal climate zones. The average rates of CH3Cl emission from the fern were similar (~1-4 µg g(dw)-1 h-1) among three areas, and there was no significant seasonal change in the temperate zone, although the rate was highly variable among individual plants. These findings suggest that meteorological climate such as temperature and solar radiation is not a major environmental factor controlling biogenic CH3Cl emission of individual plants, but species with high CH3Cl emission activity are more abundant in tropical and subtropical zones. We also found that developmental stage might be an important factor controlling biogenic CH3Cl emission rates. These results have implications for predicting future global CH3Cl emission budgets and for understanding of the plant-atmosphere interaction.

  20. Phylogeny and character evolution of the fern genus Tectaria (Tectariaceae) in the Old World inferred from chloroplast DNA sequences.

    Science.gov (United States)

    Ding, Hui-Hui; Chao, Yi-Shan; Callado, John Rey; Dong, Shi-Yong

    2014-11-01

    In this study we provide a phylogeny for the pantropical fern genus Tectaria, with emphasis on the Old World species, based on sequences of five plastid regions (atpB, ndhF plus ndhF-trnL, rbcL, rps16-matK plus matK, and trnL-F). Maximum parsimony, maximum likelihood, and Bayesian inference are used to analyze 115 individuals, representing ca. 56 species of Tectaria s.l. and 36 species of ten related genera. The results strongly support the monophyly of Tectaria in a broad sense, in which Ctenitopsis, Hemigramma, Heterogonium, Psomiocarpa, Quercifilix, Stenosemia, and Tectaridium should be submerged. Such broadly circumscribed Tectaria is supported by the arising pattern of veinlets and the base chromosome number (x=40). Four primary clades are well resolved within Tectaria, one from the Neotropic (T. trifoliata clade) and three from the Old World (T. subtriphylla clade, Ctenitopsis clade, and T. crenata clade). Tectaria crenata clade is the largest one including six subclades. Of the genera previously recognized as tectarioid ferns, Ctenitis, Lastreopsis, and Pleocnemia, are confirmed to be members in Dryopteridaceae; while Pteridrys and Triplophyllum are supported in Tectariaceae. To infer morphological evolution, 13 commonly used characters are optimized on the resulting phylogenetic trees and in result, are all homoplastic in Tectaria.

  1. Forests and the European Union Resource Network(FERN)%森林屯欧盟资源网络

    Institute of Scientific and Technical Information of China (English)

    何勖

    2011-01-01

    @@ 森林与欧盟资源网络(FERN) 成立于1995年,是一个以跟进欧盟森林政策信息以及与森林保护相关的NGO 活动的欧洲非政府组织.FREN的主要工作围绕森林以及与森林相关的人权事务,例如森林贸易、森林投资或气候变化问题.在以往的工作中,FERN与许多国际性的社会团体或环保组织建立了密切的联系,形成了广阔的关系网."FERN"不仅代表其英文名称的缩写,也是英文"蕨类植物"的意思,而蕨类植物是少数几种能在任何森林中都能够顽强生长的植物.

  2. The suppressive activities of six sources of medicinal ferns known as gusuibu on heat-labile enterotoxin-induced diarrhea.

    Science.gov (United States)

    Chang, Hung-Chi; Chen, Jaw-Chyun; Yang, Jiun-Long; Tsay, Hsin-Sheng; Hsiang, Chien-Yun; Ho, Tin-Yun

    2014-02-18

    Diarrheal disease is one of the most important worldwide health problems. Enterotoxigenic Escherichia coli (ETEC) is the most frequently isolated enteropathogen in diarrheal diseases. In developing countries, a very large number of people, especially children, suffer from diarrhea. To combat this problem, World Health Organization has constituted the Diarrhea Diseases Control Program which guides studies on traditional medicinal practices and preventive measures. Gusuibu, a traditional folk medicine, has been claimed to heal certain types of diarrhea. However, so far no scientific study has been carried out on the anti-diarrheal mechanism of Gusiubu. The present study was performed to examine the suppressive activities of ethanol extracts of six sources of folk medicinal ferns used as Gusuibu on heat-labile enterotoxin (LT)-induced diarrhea. Inhibitory effects of six sources were evaluated on the ETEC LT subunit B (LTB) and monosialotetrahexosylganglioside (GMI) interaction by GM1-enzyme linked immunosorbent assay and patent mouse gut assay. Our results indicated that Drynaria fortunei had no anti-diarrheal effect, while, among the remaining five folk medicinal ferns, four belonging to family Davalliaceae had significant abilities on both the blocking of LTB and GM1 interaction and the inhibition of LT-induced diarrhea. In conclusion, these findings suggested the potential application of Gusuibu as an anti-diarrheal remedy.

  3. Distribution patterns of ferns and lycophytes in the Coastal Region of the state of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Gonzatti

    2016-01-01

    Full Text Available ABSTRACT A survey of ferns and lycophytes of the Coastal Region of the state of Rio Grande do Sul (CRRS was performed based on field work and collections of the main regional herbaria. The following were evaluated for each species: preferential habits (terrestrial, epiphytic or aquatic, geographic distribution patterns and habitats (forest, grassland, and wetland. The occurrence of a latitudinal gradient in diversity was tested over five latitudinal ranges using the Sørensen Similarity Index. A total of 17 lycophyte and 206 fern species representing 28 families was found between the latitudes of 29° and 34°S. Exclusively terrestrial species were predominant (162, with the majority (113 exhibiting wide Neotropical distributions, followed by species that also occurred in the state of Paraná (44. The forest habitat harbored the greatest number of species (159, while grasslands had the fewest (26. Cluster analysis showed pronounced floristic differentiation among latitudinal Ranges III (31°01' to 32°S and IV (32°01' to 31°S, with a similarity index of only 0.41. Our results demonstrate a strong north-to-south reduction in species richness in the study area, which is related to environmental conditions along the latitudinal gradient and, especially, microclimatic differences in the transition zone between the Atlantic Forest and Pampa biomes.

  4. The Suppressive Activities of Six Sources of Medicinal Ferns Known as Gusuibu on Heat-Labile Enterotoxin-Induced Diarrhea

    Directory of Open Access Journals (Sweden)

    Hung-Chi Chang

    2014-02-01

    Full Text Available Diarrheal disease is one of the most important worldwide health problems. Enterotoxigenic Escherichia coli (ETEC is the most frequently isolated enteropathogen in diarrheal diseases. In developing countries, a very large number of people, especially children, suffer from diarrhea. To combat this problem, World Health Organization has constituted the Diarrhea Diseases Control Program which guides studies on traditional medicinal practices and preventive measures. Gusuibu, a traditional folk medicine, has been claimed to heal certain types of diarrhea. However, so far no scientific study has been carried out on the anti-diarrheal mechanism of Gusiubu. The present study was performed to examine the suppressive activities of ethanol extracts of six sources of folk medicinal ferns used as Gusuibu on heat-labile enterotoxin (LT-induced diarrhea. Inhibitory effects of six sources were evaluated on the ETEC LT subunit B (LTB and monosialotetrahexosylganglioside (GMI interaction by GM1-enzyme linked immunosorbent assay and patent mouse gut assay. Our results indicated that Drynaria fortunei had no anti-diarrheal effect, while, among the remaining five folk medicinal ferns, four belonging to family Davalliaceae had significant abilities on both the blocking of LTB and GM1 interaction and the inhibition of LT-induced diarrhea. In conclusion, these findings suggested the potential application of Gusuibu as an anti-diarrheal remedy.

  5. Acrostichum, a Pioneering Fern of Floodplain Areas from the Late Oligocene Sariñena Formation of the Iberian Peninsula

    Science.gov (United States)

    Ferrer, Javier; Diez, José B.

    2016-01-01

    Acrostichum is considered today an opportunistic fern in disturbed areas, which indicates the first stages of colonisation of such zones. However, in the fossil record, Acrostichum appears related to fluvio-lacustrine environments, freshwater marshes and mangrove deposits. We report here for first time fossil evidence of Acrostichum that reveals a pioneering behaviour of this fern in the colonisation of perturbed communities in Europe, which corroborates previous assumptions about the paleobiology of Acrostichum. Plant remains were collected from the Chattian (late Oligocene) La Val fossil site (Estadilla, Huesca, northeastern Spain) belonging to the Sariñena Formation, which mainly embraces crevasse splays, levees and floodplain deposits. Evidence shows that Acrostichum grew within the levee’s vegetal community or close to/on the river banks as well as on floodplain areas and closer to/on the shores of ephemeral ponds. But most importantly, the observed co-existence of Equisetum and Acrostichum remains in the same beds indicates that such strata represent short-lived inundated terrains, e.g., floodplains where the water table was temporarily stagnant. Evidence shows wetland environments dominated by pioneering taxa, implying a pioneering role for Acrostichum during the late Oligocene in the Iberian Peninsula. PMID:27631099

  6. Detection of Ptaquilosides in different phenologic stages of Bracken fern (Pteridium aquilinum) and analysis of milk samples in farms with hematuria in Tolima, Colombia

    Science.gov (United States)

    Bracken fern or “Helecho Macho” (Pteridium aquilinum) is one of the most common weeds in the meadows of the mountain ranges of Colombia. Consumption of this palatable plant by bovines causes a disease known as bovine enzootic hematuria and esophageal neoplasia. The toxic effect of the plant in bovin...

  7. Two fern species new to New Hampshire, with comments on the generation of calcareous-like habitat by base-poor rocks

    Science.gov (United States)

    Scott W. Bailey

    2013-01-01

    Incidental to other field investigations, I happened upon small populations of two fern species not previously reported from New Hampshire: Pellaea atropurpurea (L.) Link and Dryopteris filix-mas (L.) Schott. Both species are typically associated with calcareous habitats, although limestone and marble are nearly absent from New...

  8. A monograph of the fern Genus Microsorum (Polypodiaceae) including an attempt towards a reconstruction of the phylogenetic history of the microsoroids

    NARCIS (Netherlands)

    Bosman, M.T.M.

    1991-01-01

    This revision is a monographic treatment of the fern genus Microsorum (Polypodiaceae). To elucidate the problematic generic delimitation and systematic position of this genus an additional selection of 26 possibly related species was also studied. Most of these related species are traditionally plac

  9. About the history of the development of the ( Polypodiophyta ) fern collection at the Central Botanical Garden of the National Academy of Sciences of Belarus

    OpenAIRE

    Chertovich Valentina N.

    2015-01-01

    Today, the ( Polypodiophyta ) fern collection at the Central Botanical Garden of the National Academy of Sciences of Belarus includes 88 species and intraspecific taxa (31 genus, 12 families). It contains information about the main stages of collection’s development, options for its update, taxonomic composition and basic life forms. The collection presents possibilities for practical use of certain species.

  10. Improving collection efforts to avoid loss of biodiversity: lessons from comprehensive sampling of lycophytes and ferns in the subtropical Atlantic Forest

    Directory of Open Access Journals (Sweden)

    André Luís de Gasper

    2016-01-01

    Full Text Available ABSTRACT Estimating species richness with herbarium data and new collections allows us to understand the distribution of diversity. We investigated the accuracy of lycophyte and fern sampling along a vegetation gradient in the subtropical Atlantic Forest in southern Brazil. We compiled lycophyte and fern collection metadata and estimated species richness and assessed sampling accuracy for sixty 50 x 50 km units using ACE, Chao 1, Chao 2, Jackknife 1 and Jackknife 2 estimators. We compiled data for 12,779 fern specimens of 441 species, 67 of which were sampled in only one unit (singletons and 35 in two units (duplicates. Of the 60 units examined, only 11 had observed values that were above 70% of their estimated values, and 14 had observed levels between 65-70% of the estimated values, meaning that 35 units had a sampling accuracy of less than 65%. In spite of the long history of lycophyte and fern collecting in the study area, there remain units with a lower than expected sampling accuracy for a subtropical forest. This finding indicates that a sizeable collection effort is needed in order to discover the actual distribution of species before the effects of fragmentation and deforestation become permanent.

  11. About the history of the development of the ( Polypodiophyta fern collection at the Central Botanical Garden of the National Academy of Sciences of Belarus

    Directory of Open Access Journals (Sweden)

    Chertovich Valentina N.

    2015-12-01

    Full Text Available Today, the ( Polypodiophyta fern collection at the Central Botanical Garden of the National Academy of Sciences of Belarus includes 88 species and intraspecific taxa (31 genus, 12 families. It contains information about the main stages of collection’s development, options for its update, taxonomic composition and basic life forms. The collection presents possibilities for practical use of certain species.

  12. Francisco Vera Fernández de Córdoba. Matemático-humanista (Humanista-matemático) extremeño

    OpenAIRE

    Cobos, José

    1994-01-01

    En este trabajo se da una pequeña reseña bio-bibliográfica del ilustre matemático extremeño Francisco Vera Fernández de Córdoba. como cultivador del pensamiento científico, muerto en el exilio (Argentina) en el año 1967.

  13. Indicios futuristas en la estética y la obra literaria de Wenceslao Fernández Flórez

    OpenAIRE

    Couto Cantero, Pilar

    2016-01-01

    El presente artículo estudia la conexión existente entre el escritor Wenceslao Fernández Flórez y la corriente futurista de principios del siglo XX. Los dos primeros apartados abordan el estado de la cuestión en Galicia y el modo en que los escritore

  14. Metabolic adaptation, a specialized leaf organ structure and vascular responses to diurnal N2 fixation by nostoc azollae sustain the astonishing productivity of azolla ferns without nitrogen fertilizer

    NARCIS (Netherlands)

    Brouwer, Paul; Bräutigam, Andrea; Buijs, Valerie A.; Tazelaar, Anne O.E.; van der Werf, Adrie; Schlüter, Urte; Reichart, Gert-Jan|info:eu-repo/dai/nl/165599081; Bolger, Anthony; Usadel, Björn; Weber, Andreas P.M.; Schluepmann, Henriette|info:eu-repo/dai/nl/304827819

    2017-01-01

    Sustainable agriculture demands reduced input of man-made nitrogen (N) fertilizer, yet N2 fixation limits the productivity of crops with heterotrophic diazotrophic bacterial symbionts. We investigated floating ferns from the genus Azolla that host phototrophic diazotrophic Nostoc azollae in leaf

  15. Chloroplast phylogeny of asplenioid ferns based on rbcL and trnL-F Spacer sequences (Polypodiidae, aspleniaceae) and its implications for biogeography

    NARCIS (Netherlands)

    Schneider, H.; Russell, S.J.; Cox, C.J.; Bakker, F.T.; Henderson, S.; Rumsey, F.; Barrett, J.; Gibby, M.; Vogel, J.C.

    2004-01-01

    Molecular phylogenies have been generated to investigate relationships among species and putative segregates in Asplenium, one of the largest genera in ferns. Of the ~700 described taxa, 71 are included in a phylogenetic analysis using the chloroplast rbcL gene and trnL-F spacer. Our results support

  16. Rapid response of leaf photosynthesis in two fern species Pteridium aquilinum and Thelypteris dentata to changes in CO2 measured by tunable diode laser absorption spectroscopy.

    Science.gov (United States)

    Nishida, Keisuke; Kodama, Naomi; Yonemura, Seiichiro; Hanba, Yuko T

    2015-09-01

    We investigated stomatal conductance (g(s)) and mesophyll conductance (g(m)) in response to atmospheric CO2 concentration [CO2] in two primitive land plants, the fern species Pteridium aquilinum and Thelypteris dentata, using the concurrent measurement of leaf gas exchange and carbon isotope discrimination. [CO2] was initially decreased from 400 to 200 μmol mol(-1), and then increased from 200 to 700 μmol mol(-1), and finally decreased from 700 to 400 μmol mol(-1). Analysis by tunable diode laser absorption spectroscopy (TDLAS) revealed a rapid and continuous response in g m within a few minutes. In most cases, both ferns showed rapid and significant responses of g m to changes in [CO2]. The largest changes (quote % decrease) were obtained when [CO2] was decreased from 400 to 200 μmol mol(-1). This is in contrast to angiosperms where an increase in g(m) is commonly observed at low [CO2]. Similarly, fern species observed little or no response of g(s) to changes in [CO2] whereas, a concomitant decline of g(m) and g(s) with [CO2] is often reported in angiosperms. Together, these results suggest that regulation of g(m) to [CO2] may differ between angiosperms and ferns.

  17. Antibody-based screening of cell wall matrix glycans in ferns reveals taxon, tissue and cell-type specific distribution patterns

    DEFF Research Database (Denmark)

    Leroux, Olivier; Sørensen, Iben; Marcus, Susan E.;

    2015-01-01

    across the ferns and specifically associated with phloem cell walls and similarly the LM11 xylan epitope was associated with xylem cell walls. The LM5 galactan and LM6 arabinan epitopes, linked to pectic supramolecules in angiosperms, were associated with vascular structures with only limited detection...

  18. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots.

    Science.gov (United States)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises the questions of how auxin and cytokinin govern fern root system architecture and whether this can tell us something about the origin of that root. Using Azolla filiculoides, we characterized the influence of IAA and zeatin on adventitious fern root meristems and vasculature by Nomarski microscopy. Simultaneously, RNAseq analyses, yielding 36,091 contigs, were used to uncover how the phytohormones affect root tip gene expression. We show that auxin restricts Azolla root meristem development, while cytokinin promotes it; it is the opposite effect of what is observed in Arabidopsis. Global gene expression profiling uncovered 145 genes significantly regulated by cytokinin or auxin, including cell wall modulators, cell division regulators and lateral root formation coordinators. Our data illuminate both evolution and development of fern roots. Promotion of meristem size through cytokinin supports the idea that root meristems of euphyllophytes evolved from shoot meristems. The foundation of these roots was laid in a postembryonically branching shoot system. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  19. Biometry of stomata in Blechnum species (Blechnaceae with some taxonomic and ecological implications for the ferns

    Directory of Open Access Journals (Sweden)

    José María Gabriel y Galán

    2011-03-01

    Full Text Available Morphological stomatal traits, such as size, form and frequency, have been subject of much literature, including their relationships with environmental factors. However, little effort have focused on ferns, and very few in the genus Blechnum. Stomatal length, width and frequency (as stomatal index of a number of specimens of fourteen Neotropical species of Blechnum were measured in adult pinnae. The aim of the work was to find biometrical relationships between stomatal traits and between stomatal traits and habit, habitat and ecosystem of the plants. Statistical analyses of data were conducted using Exploratory Data Analysis and Multivariate Statistical Methods. Stomatal length and width showed a very high correlation, suggesting an endogenous, genetic control, thus giving these traits a considerable diagnostic utility. With respect to the relationships between stomatal traits and environment, we found significant statistical relationships between altitude and stomatal index. We also addressed the interpretation of the ecological- selective significance of various assemblages of stomatal traits in a diverse conjunction of habits, habitats and ecosystems. Rev. Biol. Trop. 59 (1: 403-415. Epub 2011 March 01.Los caracteres morfológicos estomáticos, tales como tamaño, forma y frecuencia, han sido objeto de abundante investigación, incluyendo su relación con los factores ambientales. Sin embargo, poco esfuerzo se ha realizado en esta materia en helechos y menos todavía en el género Blechnum. En este trabajo se midieron la longitud, anchura y frecuencia (como índice estomático de estomas de pinnas adultas de un número de individuos en catorce especies de Blechnum neotropicales. El objetivo fue encontrar relaciones biométricas entre los caracteres estomáticos, y entre los caracteres estomáticos y el hábito, hábitat y ecosistema de las plantas. Se realizaron análisis estadísticos como Análisis Exploratorios de Datos y Métodos Estad

  20. Diversity, genetic structure and evidence of outcrossing in British populations of the rock fern Adiantum capillus-veneris using microsatellites.

    Science.gov (United States)

    Pryor, K V; Young, J E; Rumsey, F J; Edwards, K J; Bruford, M W; Rogers, H J

    2001-08-01

    Microsatellites were isolated and a marker system was developed in the fern Adiantum capillus-veneris. Polymorphic markers were then used to study the genetic diversity and structure of populations within the UK and Ireland where this species grows at the northern edge of its range, requiring a specific rock habitat and limited to a few scattered populations. Three dinucleotide loci detected a high level of diversity (23 alleles and 28 multilocus genotypes) across the UK and Ireland, with nearly all variation partitioned among rather than within populations. Of 17 populations represented by multiple samples, all except four were monomorphic. Heterozygosity was detected in three populations, all within Glamorgan, Wales (UK), showing evidence of outcrossing. We make inferences on the factors determining the observed levels and patterns of genetic variation and the possible evolutionary history of the populations.

  1. Biostratigraphic evidence of dramatic Holocene uplift of Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific Ocean

    Directory of Open Access Journals (Sweden)

    P. Sepúlveda

    2014-09-01

    Full Text Available A study of the biostratigraphy and sedimentology of Holocene deposits on Robinson Crusoe Island (RCI on the Juan Fernández Ridge (JFR indicates that a~dramatic but localized uplift occurred since 8000 BP, at a rate of about 8.5 mm yr−1. In fact, supratidal flats and sand layers with marine gastropods (mostly Nerita sp. are now exposed ca. 70 m a.s.l., and covered by transitional dunes. The last volcanic activity on RCI occurred at ca. 0.8 Ma (active hotspot located 280 km further west and there is no sign of a compensating bulge that explains this uplift, isobaths of the sea floor instead suggesting general subsidence. However, modeling indicates that large-scale landslides followed by isostatic rebound are a viable explanation, partially reflected in the low-resolution bathymetry of the area.

  2. THE EFFECT OF Anredera cordifolia (Ten. Steenis SUPPLEMENTATION ON UTERINE INVOLUTION PROCESS EVALUATED BY OESTRUS POST PARTUM BEHAVIOR AND FERNING

    Directory of Open Access Journals (Sweden)

    R. Purwasih

    2014-09-01

    Full Text Available The aim of this study was to determine the effect of Anrederacordifolia (Ten. Steenissupplementation on uterine involution process in rabbit. The research design applied was completelyrandomized design with 4 treatments and 3 replications (T0 = without Anredera cordifoliasupplementation; TI = Anredera cordifolia supplemented two days before parturition; T2 = Anrederacordifolia supplemented two days after parturition; T3 = Anredera cordifolia supplemented two daysbefore until two days after parturition. The results showed that Anredera cordifolia (Ten. Steenissupplementation could accelerate post partum oestrus in does that were characterized by post partumoestrus behavior, ferning of saliva and cervical mucus. The best treatment was T3, that was four daysAnredera cordifolia supplementation that was administered at 0.45 g/kg of body weight/day. Furtherresearch was needed to find an optimal dose of Anredera cordifolia (Ten. Steenis on uterine involution.

  3. Richness of ferns and lycophytes in a gallery forest in the central region of Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Rodrigo Lehn

    2013-03-01

    Full Text Available This paper presents the floristic survey of ferns and lycophytes occurring in a gallery forest in the central region of Mato Grosso do Sul, Brazil. In the study area, 29 species and 2 varieties were recorded. Dryopteridaceae and Pteridaceae were the richest families (8 and 5 species, respectively and Elaphoglossum and Blechnum were the richest genera (3 species each one. Preferably, the listed species occur within the forest (68%, they occupy the terrestrial substrate (77.4%, and they are hemicryptophyte (77.4% and rosulate (64.5%. We observed four species still not mentioned for Mato Grosso do Sul, which are Blechnum lanceola L., Elaphoglossum pachydermum (Fée T. Moore, Lindsaea lancea (L. Bedd var lancea, and Mickelia nicotianifolia (Sw. R. C. Moran et al., which has its southern limit of distribution in Brazil, in the study area.

  4. El Cura Juan Fernández de Sotomayor y Picón y los catecismos de la Independencia

    OpenAIRE

    Ocampo López, Javier

    2010-01-01

    Este libro presenta el entorno revolucionario de finales del siglo XVIII y primera mitad del siglo XIX, a través del pensamiento y la acción del cura cartagenero Juan Fernández de Sotomayor y Picón, Cura de Mompós y rector del colegio Mayor de Nuestra Señora del Rosario, quien vivió en los años que dieron nacimiento a la República de Colombia. Se desempeñó como cura revolucionario, como político de Mompós, de Cartagena de Indias, ante el Congreso de las Provincias Unidas del Congreso Nacional...

  5. Botanical and geological significance of potassium-argon dates from the Juan Fernández Islands

    Science.gov (United States)

    Stuessy, Tod F.; Foland, K.A.; Sutter, John F.; Sanders, Roger W.; Silva, O. Mario

    1984-01-01

    Potassium-argon dating of five basalts from the three main islands of the Juan Fernández (or Robinson Crusoe) Islands of Chile in the southeastern Pacific gives ages of 1.01 ± 0.12 and 2.44 ± 0.14 million years for Masafuera, 3.79 ± 0.20 and 4.23 ± 0.16 for Masatierra, and 5.8 ± 2.1 for Santa Clara. These ages are much younger than that of the underlying oceanic plate and are consistent with the origin of the island-seamount chain from a mantle hot spot beneath the eastward moving Nazca plate. The young age for the archipelago suggests that speciation within endemic genera has occurred within the past 4 to 5 million years. Endemic genera of apparently more ancient origins, such as Lactoris and Thyrsopteris, have apparently dispersed to the islands and survive refugially.

  6. Biostratigraphic evidence of dramatic Holocene uplift of Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific Ocean

    Science.gov (United States)

    Sepúlveda, P.; Le Roux, J. P.; Lara, L. E.; Orozco, G.; Astudillo, V.

    2014-09-01

    A study of the biostratigraphy and sedimentology of Holocene deposits on Robinson Crusoe Island (RCI) on the Juan Fernández Ridge (JFR) indicates that a~dramatic but localized uplift occurred since 8000 BP, at a rate of about 8.5 mm yr-1. In fact, supratidal flats and sand layers with marine gastropods (mostly Nerita sp.) are now exposed ca. 70 m a.s.l., and covered by transitional dunes. The last volcanic activity on RCI occurred at ca. 0.8 Ma (active hotspot located 280 km further west) and there is no sign of a compensating bulge that explains this uplift, isobaths of the sea floor instead suggesting general subsidence. However, modeling indicates that large-scale landslides followed by isostatic rebound are a viable explanation, partially reflected in the low-resolution bathymetry of the area.

  7. Dr. Antonio Fernández Mirabal, ejemplo de profesor, cirujano maxilofacial y oncólogo

    Directory of Open Access Journals (Sweden)

    Raúl Jorge Pupo Triguero

    Full Text Available En febrero de 1962, el Dr. Antonio Fernández Mirabal se incorporó como Instructor de Cirugía Bucal a la Facultad de Estomatología de La Habana. Un mes después fue enviado al Instituto Nacional de Oncología y Radiobiología para pasar un curso de Oncología Bucal, al término del cual compartió su vida laboral entre la mencionada facultad y el instituto, mientras comenzaba una ascendente carrera de superación profesional, académica y científica. El presente trabajo tiene como objetivo dar a conocer la trayectoria profesional, académica e investigativa del Dr. Antonio Fernández Mirabal. En el mes de mayo de 2013 se realizó una entrevista personal. Posteriormente se consultó su expediente docente en el Departamento de Cuadros de la Facultad de Estomatología de La Habana y se consultaron otras fuentes bibliográficas publicadas. Se destacaron los aspectos de su formación escolar, su entorno familiar y sus estudios universitarios de pregrado y posgrado, donde se mostraban los diferentes títulos alcanzados, sus temas de investigación, su contribución a la docencia de pregrado y posgrado, así como las medallas, reconocimientos y distinciones obtenidas durante más de 50 años de vida laboral. La vida de este destacado profesor es un ejemplo a imitar por los jóvenes graduados profesionales de la salud en general y por los cirujanos maxilofaciales, oncólogos y cirujanos de cabeza y cuello.

  8. El manuscrito jerezano de La Mojigata, comedia de Leandro Fernández de Moratín

    Directory of Open Access Journals (Sweden)

    López Romero, José

    2003-12-01

    Full Text Available The volume found in the Public Library of Jerez containing three Spanish Comedies by Leandro Fernández de Moratín, has the enormous importance of including first editions of both The new comedy (1792 and The old man and the little girl (1790, and especially a manuscript copy of The prude, a work which circulated in literary circles of Madrid during the early 1790s, and being even performed in some of them without Moratin's permission. This article tries to compare the Jerez manuscript copy with others already known, and with final edition of de work, and at the same time to shed some light on the identity of the owner of the volume where The prude is included.El volumen encontrado en la Biblioteca Municipal de Jerez de la Frontera con tres Comedias españolas de Leandro Fernández de Moratín, tiene el enorme valor de incluir primeras ediciones de La comedia nueva (1792 y de El viejo y la niña (1790 y, sobre todo, una copia manuscrita de La mojigata, obra que en los primeros años de la década de 1790 circuló de esa forma por tertulias madrileñas, en algunas de las cuales hasta se representó sin el consentimiento de Moratín. Este trabajo intenta cotejar la copia manuscrita jerezana con otras ya conocidas y con la edición definitiva de la obra, así como arrojar alguna luz sobre la identidad del propietario del volumen en el que aquélla se incluye.

  9. Photosynthesis-dependent but neochrome1-independent light positioning of chloroplasts and nuclei in the fern Adiantum capillus-veneris.

    Science.gov (United States)

    Sugiyama, Yuka; Kadota, Akeo

    2011-03-01

    Chloroplasts change their positions in the cell depending on the light conditions. In the dark, chloroplasts in fern prothallia locate along the anticlinal wall (dark position). However, chloroplasts become relocated to the periclinal wall (light position) when the light shines perpendicularly to the prothallia. Red light is effective in inducing this relocation in Adiantum capillus-veneris, and neochrome1 (neo1) has been identified as the red light receptor regulating this movement. Nevertheless, we found here that chloroplasts in neo1 mutants still become relocated from the dark position to the light position under red light. We tested four neo1 mutant alleles (neo1-1, neo1-2, neo1-3, and neo1-4), and all of them showed the red-light-induced chloroplast relocation. Furthermore, chloroplast light positioning under red light occurred also in Pteris vittata, another fern species naturally lacking the neo1-dependent phenomenon. The light positioning of chloroplasts occurred independently of the direction of red light, a response different to that of the neo1-dependent movement. Photosynthesis inhibitors 3-(3,4 dichlorophenyl)-1,1-dimethylurea or 2,5-dibromo-3-isopropyl-6-methyl-p-benzoquinone blocked this movement. Addition of sucrose (Suc) or glucose to the culture medium induced migration of the chloroplasts to the periclinal wall in darkness. Furthermore, Suc could override the effects of 3-(3,4 dichlorophenyl)-1,1-dimethylurea. Interestingly, the same light positioning was evident for nuclei under red light in the neo1 mutant. The nuclear light positioning was also induced in darkness with the addition of Suc or glucose. These results indicate that photosynthesis-dependent nondirectional movement contributes to the light positioning of these organelles in addition to the neo1-dependent directional movement toward light.

  10. Rock paintings in Fern Cave, Lava Beds National Monument, California: Not the 1054 A.D. (Crab Nebula) Supernova

    Energy Technology Data Exchange (ETDEWEB)

    Armitage, R.A.; Hyman, M.; Rowe, M. W. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Southon, J. [Lawrence Livermore National Lab., CA (United States). Center for Accelerator Mass Spectrometry; Barat, C. [Lava Beds National Monument, Tule Lake, CA (United States)

    1997-12-31

    On July 4, 1054 A.D. a supernova brighter than Venus appeared in the sky, remaining visible for approximately 23 days and 650 nights. It was chronicled in five independent historic accounts, four in China and one in Japan. For at least 40 years investigators have attributed certain distinctive rock paintings and carvings in the western United States as recordings of the 1054 A.D. supernova. More than twenty such depictions (circle or star-like symbols and a crescent) have been located. Two panels of rock paintings in Lava Beds National Monument, California, one at Fern Cave and one at Symbol Bridge, were listed as recording the 1054 A.D. supernova. The only direct means of assessing the likelihood that a `supernova` representation records the 1054 A.D. event is to date the rock painting or carving. At Texas A and M University, was developed a plasma-chemical extraction technique that permits to analyze the {sup 14}C in rock paintings, whether the pigments used were charcoal or inorganic Fe- and Mn- oxides and hydroxides with organic binder/vehicles. This paper presents direct {sup 14}C age estimates on a rock painting suggested to represent the 1054 A.D. supernova. Charcoal pigment samples were collected from three figures in proximity at Fern Cave: a crescent pointing downward and two nearby circles, one above and one below the crescent. The AMS {sup 14}C analysis on each sample using this technique show that these images do not represent the 1054 A.D. supernova. Paper no. 59; Extended abstract. 1 tab.

  11. Evaluation of the anti-inflammatory and antioxidative potential of four fern species from China intended for use as food supplements.

    Science.gov (United States)

    Dion, Carine; Haug, Christian; Guan, Haifeng; Ripoll, Christophe; Spiteller, Peter; Coussaert, Aurelie; Boulet, Elodie; Schmidt, Daniel; Wei, Jianbing; Zhou, Yijun; Lamottke, Kai

    2015-04-01

    Inflammation plays a major role in many diseases, for instance in arteriosclerosis, rheumatoid arthritis, autoimmune disorders and cancer. Since many plants contain compounds with anti-inflammatory activity, their consumption may be able to prevent the development of inflammatory-based diseases. Edible ferns are some of the most important wild vegetables in China and have traditionally been used both for dietary and therapeutic purposes. In this study we investigated the anti-inflammatory and antioxidant potential of fern extracts from Matteuccia struthiopteris, Osmundajaponica, Matteuccia orientalis and Pteridium aquilinum intended for use as nutraceuticals. Two modes of action were investigated: the inhibition of the pro-inflammatory gene expression of interleukin-1 beta (IL1-β) and interleukin-6 (IL6), and the gene expression of iNOS by LPS-elicited macrophages. The results showed a decrease of IL1-β gene expression for the five fern extracts. This effect was more pronounced for the extracts prepared from the roots of O. japonica (IC50 of 17.8 µg/mL) and the young fronds of M orientalis (50.0 µg/mL). Regarding the indirect measurement of NO, via iNOS gene expression, an interesting decrease of 50% was obtained with the extract of M. orientalis fronds at a low concentration (20 µg/mL) compared with P. aquilinum fronds (160 µg/mL) and leaves of O. japonica. The latter showed a higher decrease but at a high concentration of extract (160 µg/mL). The five fern extracts were also evaluated for their ability to scavenge 2,2-diphenyl-l-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). All fern extracts exhibited antioxidant effects but the roots of O. japonica and the fronds of M orientalis were most efficient. The HPLC-MS analysis of the constituents of the fern extracts confirmed the presence of chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, kaempferol and apigenin, molecules known to exhibit

  12. 干旱胁迫对蕨类植物生理指标的影响%Effect of Drought Stress on Physiological Index of Fern

    Institute of Scientific and Technical Information of China (English)

    杨海艳; 李雪玲; 王波; 蒋熙原; 徐成东

    2011-01-01

    [目的]研究干旱胁迫下蕨类植物生理指标的变化.[方法]采用人工模拟干旱胁迫-复水方法,对5种蕨类植物(肾蕨、凤尾蕨、蜈蚣蕨、铁线蕨、毛蕨)进行干旱处理,研究了干旱胁迫对其叶片相对含水量、相对电导率、叶绿素含量及游离脯氨酸含量等相关生理指标的影响.[结果]随着干旱胁迫时间的延长,5种蕨类植物叶片相对含水量和叶绿素含量均呈下降趋势,而相对电导率和游离脯氧酸含量呈上升趋势;干旱胁迫下,肾蕨各生理指标均好于其他蕨类植物,尤其在胁迫12 d时,差异达显著水平,说明肾蕨的抗旱能力最强;复水后,5种蕨类植物的生理指标均有不同程度的恢复.[结论]该研究可为蕨类植物的开发利用提供理论依据.%[ Objective ] The physiological index variation of fern was studied under drought stress. [ Method ] By means of artificial simulated drought stress and rehydration, the effect of drought stress on physiological indexes ( leaf relative water content, relative conductivity, chlorophyll content and free proline content) of five ferns ( Nephrolepis auriculata, Pteris multiflda, Pteris vittata, Adiantum capillus and Cyclosorus interruptus ) was studied in our paper. [ Result ] With drought stress time prolonging, the leaf relative water content and chlorophyll content of five ferns showed decrease trend, while there was an increase trend in relative conductivity and free proline content; the physiological indexes of Nephrolepis auriculata under drought stress were better than other ferns, with obvious difference after 12 days of stress, and it showed that Nephrolepis auriculata had strongest drought-resistant ability; after rehydration, the physiological indexes of five ferns recovered at different degree. [ Conclusion] Our study could provide theoretical basis for the development and utilization of fern.

  13. Investigation and Utilization of Wild Ornamental Fern Resources of Mogan Mountain%莫干山风景区野生观赏蕨类植物资源调查及其应用研究

    Institute of Scientific and Technical Information of China (English)

    黄超群; 周金

    2012-01-01

    为了解莫干山风景区野生观赏蕨类植物种类,通过实地调查,共发现具有较高观赏价值的野生蕨类植物资源19科29属53种.按生态类型可分为土生、附生、石生和藤本四大类.可用于园林绿化、盆栽观赏、盆景配置以及切花配叶等.%In order to explore the plant species of wild ornamental fern resources in Mogan Mountain, a field investigation was carried out, a total of 53 species, 29 genera and 19 families of wild ornamental ferns were found out, which can be classified into four categories according to their eco-forms, including the terrestrial ferns, epiphytic ferns, lithophytic fens and vine ferns. The wild ornamental ferns can be used for landscape greening, miniascape, pot culture and cut leaves.

  14. Sporophyte morphology and gametophyte development of the fern Blechnum sprucei (Pteridophyta: Blechnaceae

    Directory of Open Access Journals (Sweden)

    Jose María Gabriel y Galán

    2008-12-01

    Full Text Available The fern Blechnum sprucei grows in Mesoamerica (Costa Rica and South America, from Colombia to Bolivia, SE and centre of Brazil, Paraguay and Argentina. It is a distinctive, somewhat vulnerable, mostly orophilous species. Fresh and dry herbarium material was used for this study. Herbarium material for anatomical studies comes from CTES, BA, LP, MA, SI and UC (Holmgren et al.1990. Selected representative specimens are additionally cited after taxonomic treatment of the species. Dry material was restored with aqueous 4:1 butil cellosolve. Pinnae were cleared with aqueous 6% NaOH, then coloured with aqueous 1 % TBO (Gurr 1966. Hand made transverse sections of young and adult stipes, and costae were done in fresh and restored herbarium material. Venation and epidermal patterns were analyzed in basal, apical and medium pinnae, but only the latter were illustrated. The size and density of stomata were measured in medium pinnae from all studied samples, values shown are the average of 25 measures per sample; sizes are expressed as minimum, media and maximum length x width, in µm, and density as minimum, media and maximum number of stomata / mm². Spores were studied with SEM, mounted on metal stubs with double sided tape, covered with gold under vacuum and photographed with a Jeol /EO JSM 6360 (15 KV SEM. Spores were also studied with light microscope, mounted in DePex (DePex mounting medium, Gurr, BDH Laboratory Supplies, Poole BH15 1TD, UK and measured using an ocular micrometer. Measurements are based on a minimum sample of 100 spores taken from different specimens. Sizes are expressed as the longest equatorial diameter/ polar diameter, in µm. Gametophytes were studied from material collected in the subtropical forest of Tucumán Province, Argentina. Spore samples for cultures were taken from single sporophytes kept dry at room temperature since the date plants were collected. Gametophytes were grown under fluorescent light. Multispore cultures

  15. La poética de la Nocilla: Transmedia Poetics in Agustín Fernández Mallo’s Complete Works.

    Directory of Open Access Journals (Sweden)

    Alex Saum-Pascual

    2014-06-01

    Full Text Available Moving beyond current applications of transmedia storytelling, this essay looks at the work of Spanish author Agustín Fernández Mallo to explore how his engagement with the media landscape is both a revolution and a contribution to fundamental concepts in contemporary literature such as authorship and narrative structure. On the one hand, transmedia storytelling provides a structure to frame Fernández Mallo’s versatile and multimedia production, exploring both the productive semiotic intermedial breakages within works, as well as analyzing his complete production as a whole: one single poetic “work” encapsulated into a transmedia universe composed of multiple autonomous narratives. On the other, the fictionalization of his Author function as a parodied metafictional object within this transmedia universe can shed some light on the role of the writer within a larger network of media convergence and neoliberal enterprises.

  16. 阳明山观赏蕨类植物资源及其开发利用%Resource and Utilization of Wild Ornamental Fern in Yangmingshan

    Institute of Scientific and Technical Information of China (English)

    蒋建军

    2011-01-01

    According to investigation and statistics, there are 378 species of wild fern belonging to 44 families, 106 genera in Yangmingshan, among which, 165 species have ornamental value. The problems existing in landscaping and suggestions were put forward for the development and utilization of ornamental ferns.%调查和统计了湖南阳明山观赏蕨类植物资源.结果表明,阳明山蕨类植物有44科106属378种,其中具观赏价值的有165种.提出了观赏蕨类植物在园林绿化中存在的问题及建议.

  17. El testamento de Gregorio Fernández y el proceso de culminación del retablo mayor de la Catedral de Plasencia (Cáceres

    Directory of Open Access Journals (Sweden)

    Méndez Hernán, Vicente

    2012-09-01

    Full Text Available This article offers the date and part of the Testament of Gregorio Fernández, thanks to the extract located in the Plasencia Cathedral Archive, which was presented to the cathedral by the sculptor’s heirs in order receive the payment due upon completion of the main altarpiece by the artist prior to his death.

    El presente artículo da a conocer la fecha y parte del testamento de Gregorio Fernández, a tenor del traslado que existe del mismo en el Archivo catedralicio de Plasencia, y a raíz de la definitiva conclusión de su retablo mayor, del que se aportan nuevos datos.

  18. Señorío y realengo. A propósito de la curaduría de don Alonso Fernández de Lugo

    OpenAIRE

    Ana Viña Brito

    2003-01-01

    El desempeño de la curaduría por parte de don Alonso Fernández de Lugo sobre los hijos de su esposa, don Guillén y doña Inés, le permitió la intervención directa en las islas de señorío y actuar como «señor de vasallos». Se analizan los antecedentes y consecuencias que tuvo la curaduría tanto para el Adelantado como para los Peraza.The Adelantado don Alonso Fernández de Lugo filled the office of the «curaduría» which entrusted him with the care over the offspring of don Guillén and doña Inés....

  19. A well-sampled phylogenetic analysis of the polystichoid ferns (Dryopteridaceae) suggests a complex biogeographical history involving both boreotropical migrations and recent transoceanic dispersals.

    Science.gov (United States)

    Le Péchon, Timothée; Zhang, Liang; He, Hai; Zhou, Xin-Mao; Bytebier, Benny; Gao, Xin-Fen; Zhang, Li-Bing

    2016-05-01

    Intercontinental disjunctions in ferns have often been considered as the result of long-distance dispersal (LDD) events rather than of vicariance. However, in many leptosporangiate groups, both processes appear to have played a major role in shaping current geographical distribution. In this study, we reconstructed the phylogenetic relationships and inferred the ancestral distribution areas of the polystichoid ferns (Cyrtomium, Phanerophlebia, and Polystichum), to evaluate the relative impact of vicariance and LDD on the biogeography of this group. We used a molecular dataset including 3346 characters from five plastid loci. With 190 accessions our taxon coverage was about three times as large as any previous worldwide sampling. Biogeographical analyses were performed using S-DIVA and S-DEC and divergence times were estimated by integrating fossil and secondary calibrations. The polystichoid ferns are a monophyletic clade that may have originated in East Asia during the Eocene, an age much younger than previously estimated. Three transoceanic disjunctions between East Asia and New World were identified in the Paleogene: one for Phanerophlebia during late Eocene (34Ma, 19-51Ma), and two in Polystichum at the Eocene-Oligocene boundary (30Ma, 18-43Ma; 28Ma, 19-39Ma respectively). During the Neogene, further range expansions took place from Asia to Africa, Hawaii, and the Southwestern Indian Ocean region. Our results indicate that early transfers between the Old and the New World are compatible with a boreotropical migration scenario. After evolving in Asia during the Eocene, the polystichoid ferns reached the New World in independent migrations at the Eocene-Oligocene boundary through the boreotropical belt. However, although less likely, the alternative hypothesis of independent transoceanic dispersals from the Old to the New World cannot be ruled out. Further range expansion during the Neogene was most likely the result of long-distance dispersal (LDD).

  20. Algunas novelas de Darío Fernández-Flórez: de Zarabanda (1944 a Alta Costura (1954. Temas escabrosos en tiempos de restricciones moralistas

    Directory of Open Access Journals (Sweden)

    Montejo Gurruchaga, Lucía

    2008-06-01

    Full Text Available Dario Fernández-Flórez begins in 1944 with Zarabanda a narrative style of intellectual eroticism and inmoral atmosphere which attracted no attention. Six years later he published Lola, espejo oscuro the recollections of a high prostitute. The novel was an scandal and an immediate success. Although the topic and its treatment were odd at the time because the strict moral values which mantained Franco´s regime were ignored, the novel was published with no cuts at all. Censorship was deaf to all the voices that warned of its dangers. This had an explanation: Darío Fernández-Flórez held an important post in the Propaganda National Service. After his dismissal censors were less lenient.Darío Fernández-Flórez inicia en 1944 con Zarabanda una narrativa de erotismo intelectualizado y ambiente amoral que no tuvo ningún eco. Seis años después publicará Lola, espejo oscuro, las memorias de una prostituta de alto copete. La novela suscitó un gran escándalo y su éxito fue inmediato. Aunque el tema y su tratamiento eran inusitados en aquellos momentos porque la obra daba al traste con los estrictos valores morales que sustentaban el régimen franquista, la novela fue publicada sin recortes; la censura hizo oídos sordos a todas las voces que alertaban de su peligro. Este hecho tiene una explicación: Darío Fernández-Flórez ocupaba un cargo importante en el Servicio Nacional de Propaganda. Tras su cese, los censores serán menos benevolentes.

  1. 蕨类植物同工酶的遗传多样性分析%Study on the Genetic Diversity of Isozyme in Ferns

    Institute of Scientific and Technical Information of China (English)

    杨海艳; 王波; 钟锡兰; 李雪玲; 徐成东

    2011-01-01

    [目的]分析26种蕨类植物同工酶的遗传多样性.[方法]分析26种蕨类植物的POD同工酶、SOD同工酶、CAT同工酶和EST同工酶的酶谱,并对其中有条带的17种材料进行聚类分析.[结果]在26种蕨类植物中,有17种在同工酶谱带上表现出丰富的遗传多样性,但其聚类分析结果与形态学分类结果不完全吻合.[结论]同工酶谱为研究蕨类植物的遗传多样性提供了好的研究方法,但不支持形态学分类.%[Objective] The research aimed to analyze the genetic diversity of isozyme in 26 kinds of ferns. [Method] The zymograms of POD isozyme,SOD isozyme,CAT isozyme and EST isozyme in 26 kinds of ferns were analyzed,and the cluster analysis on 17 kinds of materials which had the banding was carried out. [Result] In 26 kinds of ferns,here were 17 kinds displayed the rich genetic diversity in the isozymogram. But their cluster analysis result didn't totally tally with the morphological classification. [Conclusion] The isozymogram provided the good research method for studying the genetic diversity of ferns but didn't support the morphological classification.

  2. Are fern stomatal responses to different stimuli coordinated? Testing responses to light, vapor pressure deficit, and CO2 for diverse species grown under contrasting irradiances.

    Science.gov (United States)

    Creese, Chris; Oberbauer, Steve; Rundel, Phil; Sack, Lawren

    2014-10-01

    The stomatal behavior of ferns provides an excellent system for disentangling responses to different environmental signals, which balance carbon gain against water loss. Here, we measured responses of stomatal conductance (gs ) to irradiance, CO2 , and vapor pressure deficit (VPD) for 13 phylogenetically diverse species native to open and shaded habitats, grown under high- and low-irradiance treatments. We tested two main hypotheses: that plants adapted and grown in high-irradiance environments would have greater responsiveness to all stimuli given higher flux rates; and that species' responsiveness to different factors would be correlated because of the relative simplicity of fern stomatal control. We found that species with higher light-saturated gs had larger responses, and that plants grown under high irradiance were more responsive to all stimuli. Open habitat species showed greater responsiveness to irradiance and CO2 , but lower responsiveness to VPD; a case of plasticity and adaptation tending in different directions. Responses of gs to irradiance and VPD were positively correlated across species, but CO2 responses were independent and highly variable. The novel finding of correlations among stomatal responses to different stimuli suggests coordination of hydraulic and photosynthetic signaling networks modulating fern stomatal responses, which show distinct optimization at growth and evolutionary time-scales.

  3. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    Science.gov (United States)

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes.

  4. 仿射变换对二维蕨类形状控制的研究%Affine Transformation for Two-dimensional Fern Shape Control

    Institute of Scientific and Technical Information of China (English)

    包晔

    2012-01-01

    通过对仿射变换矩阵系数进行调节分析,研究仿射变换矩阵对二维蕨类形状控制的作用,并分析仿射变换矩阵的各个系数对二维蕨类植物生成的形状和弯曲方向的影响,给出了蕨类植物形状控制方法,证明能较好地控制蕨类植物叶片的生长方向和形状,但还不能够控制叶片生成的精确角度和叶片的精确大小.%In this paper, affine transformation matrix of two-dimensional fern shape control is analyzed, and the affine trans- formation matrix coefficients on the shape generated by the two-dimensional ferns are adjusted and the bending directions are given. Better controlling approaches to the direction and shape of fern leaves are put forward in detail.

  5. Richness, geographic distribution and ecological aspects of the fern community within the Murici Ecological Station in the state of Alagoas, Brazil

    Directory of Open Access Journals (Sweden)

    Anna Flora de Novaes Pereira

    2013-12-01

    Full Text Available We conducted a floristic survey of ferns within the Murici Ecological Station (remnant of the northeastern Atlantic Forest, located near the municipalities of Messias and Murici, in the state of Alagoas, Brazil. To increase knowledge of the ferns of Alagoas, we evaluated the species occurring in the study area in terms of richness, composition, geographic distribution, similarities with species in other Brazilian biomes, regional conservation status and ecological aspects. Data were obtained from field work conducted between March 2009 and September 2010. We identified 107 species of ferns, of which 19 represent new records for Alagoas. The richest families were Pteridaceae (29 species and Polypodiaceae (22 species. The richest genera were Adiantum (15 species and Thelypteris (9 species. Most of the species sampled are widely distributed throughout Brazil and the Americas. Within the context of the northeastern Atlantic Forest, 12 species were considered endangered. Concerning the ecological aspects, 88.8% of the species identified were herbaceous, 57.9% were terrestrial and 70.0% occurred in the forest interior.

  6. Almost the Same, but Not Quite: Re-Orienting the Story of the Subject in Christina Fernández Cubas's El año de Gracia

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    Jessica A. Folkart

    2002-06-01

    Full Text Available Cristina Fernández Cubas's novel El año de Gracia (1985, about a young Spaniard who is shipwrecked on a deserted island with only a mangy shepherd for company, evokes the political dialectics of self/other found in the European's discovery and conquest of an unknown island in Robinson Crusoe . In Fernández Cubas's literary depiction of the European subject, however, she situates him on the margins of power in order to view the dynamic from a different perspective. The postcolonial theorizations of Edward Said and Homi Bhabha inform this analysis of how Fernández Cubas's castaway is at first overpowered by the other and then, in his struggle for control, comes to appreciate and learn from those different qualities instead of subsuming them beneath his personal dominance. While the Spanish novel clearly foregrounds Robinson Crusoe as its model text, it also reorients the once supreme subject in the site of exclusion. Hence this protagonist tells his story from a newly formed, hybrid perspective of the oppressor and the oppressed melded into one. El año de Gracia engages conflicting visions of power in dialogue with one another, interrogating the borders that define them according to the differences they exclude. In the process, it disorients the subject in order to reorient the story that he tells as one that is almost the same as its literary forebear but, importantly, not quite.

  7. Juan Fernández Ridge (Nazca Plate): petrology and thermochronology of a rejuvenated hot spot trail

    Science.gov (United States)

    Reyes, J.; Lara, L. E.

    2012-04-01

    The Juan Fernández Ridge on the oceanic Nazca plate is thought to be a classic hot spot trail because of the apparent westward rejuvenation of the eruptive ages. However, geochronological data is still scarce and there are a few constrains to support this hypothesis like the ca. 9 Ma Ar-Ar age of the O'Higgins seamount (115 km from the Chile-Perú trench), some published K-Ar ages of ca. 3-4 Ma in Robinson Crusoe island (580 km from the trench) and ca. 1 Ma in Alejandro Selkirk (180 km further west). New reconnaissance K-Ar ages and specially the ongoing Ar-Ar dating effort in Robinson Crusoe define a ca. 1-4 Ma time span, which partially overlap with the age of Alejandro Selkirk, breaking the expected age progression given that the Nazca plate moves eastwards at ca. 6-8 cm/yr. In addition, new geological mapping shows a sharp unconformity between the older (ca. 4 Ma), strongly altered sequences and the more recent (ca. 1 Ma), post-erosional volcanic piles, where the proximal facies are still preserved. Petrological evidence also supports this evolution pattern. In fact, the partially altered older sequence is tholeiitic (Ba/Yb=12.70; La/Yb=8.12; Ba/Y=6.51; Ba/Zr=0.89). The shield stage (ca. 1-3 Ma) is transicional from tholeiitic to alkaline (Ba/Yb=18.07-8.32; La/Yb=4.59-9.84; Ba/Y=4.24-8.18; Ba/Zr=0.73-1.09) and the younger (ca. 1 Ma) is mostly alkaline (Ba/Yb=38.15; La/Yb=15.66; Ba/Y=20.27; Ba/Zr=2.31). A fixed deep-mantle plume origin for Pacific hot spots has been widely debated and concurrent phenomena arose as a possible explanation for non-linear age progressions and/or long-lived volcanic activity. In fact, intraplate regional tectonics, plume displacement, and mantle heterogeneities could be the main factor of the ridge architecture or the mask for a first-order linear trend. An ongoing mapping and dating effort is aimed to understand the evolution of the Juan Fernández Ridge, testing the main hypothesis. This research is supported by FONDECYT Project

  8. Antibacterial activity of the terrestrial fernLygodium flexuosum (L.) Sw. against multidrug resistant enteric- and uro-pathogenic bacteria

    Institute of Scientific and Technical Information of China (English)

    Nabakishore Nayak; Sibanarayan Rath; Monali P Mishra; Goutam Ghosh; Rabindra N Padhy

    2013-01-01

    Objective:To investigate antibacterial properties of the terrestrial fernLygodium flexuosum (L. flexuosum) obtained fromKalahandi district,Odisha against enteric- and uro-pathogenic bacteria isolated from clinical samples.Method:Frond-extracts ofL. flexuosum were obtained by the cold percolation method using four solvents, petroleum ether, chloroform, methanol and water.Antibacterial potencies of concentrated cold frond-extracts were tested by the agar-well diffusion method against7 multidrug resistant(MDR) bacteria of which,2 wereGram-positives, methicillin resistantStaphylococcus aureus(MRSA) and vancomycin resistantEnterococcus faecalis(VRE), and5Gram-negatives,Enterobacter aerogenes,Escherichia coli,Klebsiella pneumoniae, Pseudomonas aeruginosa andProteus mirabilis.Result:The cold-water frond-extract had the best antimicrobial activity against7MDR bacterial isolates, compared to extracts with other solvents.Values of zones of inhibition againstMRSA andP. mirabilis were the highest, 29 mm.Zones of inhibition againstVRE andP. aeruginosa were25 mm, while those were23 mm againstE. aerogenes andE. coli.The least size of zone of inhibition19 mm was recorded against K. pneumoniae.Minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC) values of active frond-extracts with water, chloroform, methanol, and petroleum ether were recorded.For the water extract, theMIC value1.562 mg/mL againstMRSA andP. mirabilis, but the value3.25 mg/mL againstVRE,E. aerogenes andP. aeruginosa, while the value of12.5 mg/mL againstK. pneumoniae were recorded.MBC values were the least with chloroform-extracts, with the range12.5 for6 bacteria, excludingP. aeruginosa for which, the value25 mg/mL was recorded asMBC.Conclusions:Phytochemical analysis of the water-extract ofL. flexuosum confirmed the presence of glycosides and carbohydrates, but alkaloids, terpenoids, steroids, saponins, tannins, and flavonoids were absent.L. flexuosum, being a fern, is a suitable non

  9. Project "Conservation, Restoration, and Development of the Juan Fernández islands, Chile" Proyecto conservación, restauración y desarrollo de las islas Juan Fernández, Chile

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    JAIME G. CUEVAS

    2001-12-01

    Full Text Available From a scientific point of view, the Juan Fernández islands contain one of the most interesting floras of the planet. Although protected as a National Park and a World Biosphere Reserve, 400 years of human interference have left deep traces in the native plant communities. Repeated burning, overexploitation of species, and the introduction of animal and plant plagues have taken 75 % of the endemic vascular flora to the verge of extinction. In 1997, Chile's national forest service (Corporación Nacional Forestal, CONAF started an ambitious project, whose objective is the recovery of this highly complex ecosystem with a socio-ecological focus. Juan Fernández makes an interesting case, as the local people (600 persons practically live within the park, therefore impeding the exclusion of the people from any conservation program. Secondly, the relatively small size of the archipelago (100 km² permits the observation of the effects of whatever modification in the ecosystem on small scales in time and space. Thirdly, the native and introduced biota are interrelated in such a way that human-caused changes in one species population may provoke unexpected results amongst other, non-target species. The project mainly deals with the eradication or control of some animal and plant plagues, the active conservation and restoration of the flora and the inclusion of the local people in conservation planning. This article presents the park's general problems, the strategy proposed to resolve them as well as some preliminary results. This project shows the complexity of the conservation activities in practice, with diverse and complex interrelations and gaps in ecological knowledge. In this respect, the project may well serve as a model for similar programs in other placesLas islas Juan Fernández albergan una de las floras más interesantes del planeta desde el punto de vista científico. Aunque están protegidas como Parque Nacional y Reserva Mundial de la

  10. The rise of the Himalaya enforced the diversification of SE Asian ferns by altering the monsoon regimes

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    Wang Li

    2012-11-01

    Full Text Available Abstract Background The rise of high mountain chains is widely seen as one of the factors driving rapid diversification of land plants and the formation of biodiversity hotspots. Supporting evidence was reported for the impact of the rapid rise of the Andean mountains but this hypothesis has so far been less explored for the impact of the “roof of the world”. The formation of the Himalaya, and especially the rise of the Qinghai–Tibetan Plateau in the recent 20 million years, altered the monsoon regimes that dominate the current climates of South East Asia. Here, we infer the hypothesis that the rise of Himalaya had a strong impact on the plant diversity in the biodiversity hotspot of the Southwest Chinese Mountains. Results Our analyses of the diversification pattern of the derived fern genus Lepisorus recovered evidence for changes in plant diversity that correlated with the strengthening of South East Asian monsoon. Southwest China or Southwest China and Japan was recovered as the putative area of origin of Lepisorus and enhancing monsoon regime were found to shape the early diversification of the genus as well as subsequent radiations during the late Miocene and Pliocene. Conclusions We report new evidence for a coincidence of plant diversification and changes of the climate caused by the uplift of the Himalaya. These results are discussed in the context of the impact of incomplete taxon sampling, uncertainty of divergence time estimates, and limitations of current methods used to assess diversification rates.

  11. Comentarios a las ponencias de Lourenzo Fernández Prieto y Marcela Sabaté Sort

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    Ricardo ROBLEDO HERNÁNDEZ

    2010-02-01

    Full Text Available La ponencia de Lorenzo Fernández Prieto empieza por reivindicar los problemas del presente como punto de partida en la construcción de la historia aconsejando tener en cuenta como referente la crisis del modelo de modernización y el fin de la ideología del progreso. Resulta llamativo que al mismo tiempo, aunque sea de forma marginal, eche una lanza a favor de Fukuyama, tildado habitualmente de ideología conservadora. Pero esto, por decirlo de algún modo, es casi una anécdota puesto que el principal foco de atención es la historia rural como el ámbito más pertinente de historia transnacional. Su ponencia es un alegato más que engrosa la corriente de opinión cada vez más caudalosa en contra de la tesis del fracaso o del excepcionalismo hispánicos. Casi hace treinta años que se está hablando en esta dirección, desde que Martínez Alier y Naredo descartaron que existiera una evolución muy diferente de la agricultura española y que el comportamiento de los grandes labradores o el carácter de las instituciones fueran factores explicativos relevantes en esa supuesta diferenciación.

  12. Fire and ice: volcanic and glacial impacts on the phylogeography of the New Zealand forest fern Asplenium hookerianum.

    Science.gov (United States)

    Shepherd, Lara D; Perrie, Leon R; Brownsey, Patrick J

    2007-11-01

    In the Southern Hemisphere there has been little phylogeographical investigation of forest refugia sites during the last glacial. Hooker's spleenwort, Asplenium hookerianum, is a fern that is found throughout New Zealand. It is strongly associated with forest and is a proxy for the survival of woody vegetation during the last glacial maximum. DNA sequence data from the chloroplast trnL-trnF locus were obtained from 242 samples, including c. 10 individuals from each of 21 focal populations. Most populations contained multiple, and in many cases unique, haplotypes, including those neighbouring formerly glaciated areas, while the predominant inference from nested clade analysis was restricted gene flow with isolation by distance. These results suggest that A. hookerianum survived the last glacial maximum in widespread populations of sufficient size to retain the observed phylogeography, and therefore that the sheltering woody vegetation must have been similarly abundant. This is consistent with palynological interpretations for the survival in New Zealand of thermophilous forest species at considerably smaller distances from the ice sheets than recorded for the Northern Hemisphere. Eastern and central North Island populations of A. hookerianum were characterized by a different subset of haplotypes to populations from the remainder of the country. A similar east-west phylogeographical pattern has been detected in a diverse array of taxa, and has previously been attributed to recurrent vulcanism in the central North Island.

  13. The rise of the Himalaya enforced the diversification of SE Asian ferns by altering the monsoon regimes.

    Science.gov (United States)

    Wang, Li; Schneider, Harald; Zhang, Xian-Chun; Xiang, Qiao-Ping

    2012-11-09

    The rise of high mountain chains is widely seen as one of the factors driving rapid diversification of land plants and the formation of biodiversity hotspots. Supporting evidence was reported for the impact of the rapid rise of the Andean mountains but this hypothesis has so far been less explored for the impact of the "roof of the world". The formation of the Himalaya, and especially the rise of the Qinghai-Tibetan Plateau in the recent 20 million years, altered the monsoon regimes that dominate the current climates of South East Asia. Here, we infer the hypothesis that the rise of Himalaya had a strong impact on the plant diversity in the biodiversity hotspot of the Southwest Chinese Mountains. Our analyses of the diversification pattern of the derived fern genus Lepisorus recovered evidence for changes in plant diversity that correlated with the strengthening of South East Asian monsoon. Southwest China or Southwest China and Japan was recovered as the putative area of origin of Lepisorus and enhancing monsoon regime were found to shape the early diversification of the genus as well as subsequent radiations during the late Miocene and Pliocene. We report new evidence for a coincidence of plant diversification and changes of the climate caused by the uplift of the Himalaya. These results are discussed in the context of the impact of incomplete taxon sampling, uncertainty of divergence time estimates, and limitations of current methods used to assess diversification rates.

  14. Identification guide to Nordic aphids associated with mosses, horsetails and ferns (Bryophyta, Equisetophyta, Polypodiophyta (Insecta, Hemiptera, Aphidoidea

    Directory of Open Access Journals (Sweden)

    Anders Christian Albrecht

    2015-10-01

    Full Text Available Keys and diagnoses of North European aphids (Hemiptera, Aphidoidea associated with mosses, horsetails and ferns are given, based on fresh and freeze-dried material. Numerous externally visible and thus informative characters, that are absent in cleared, slide-mounted specimens, such as body shape colours, wax coating and pattern etc., are utilized. Most of the species are illustrated by photographs of live specimens and drawings. Root-feeding species living in the moss layer or otherwise often present in moss samples are also included, even if their hosts were spermatophytes. The combination of colour images and diagnoses, utilizing easily observed characters, allows the identification of a large number of species already in the field, and many more at home with the aid of a stereo microscope. Host plant relationships and association with ants are summarised, including new records. Brief accounts on aphid life cycles, freeze-drying preparation techniques, etc. are also given to support the use of the keys.

  15. Pesca artesanal de cangrejo dorado (Chaceon chilensis en el archipiélago de Juan Fernández, Chile Artisanal fishing for golden crab (Chaceon chilensis off the Juan Fernández archipelago, Chile

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    Mauricio Ahumada

    2009-01-01

    Full Text Available Se describe la pesca artesanal de cangrejo dorado (Chaceon chilensis en las islas Robinson Crusoe y Santa Clara, en el archipiélago de Juan Fernández (Chile, desarrollada entre julio de 2005 y mayo de 2006. Se dan a conocer aspectos biológico-pesqueros relativos a esfuerzo y rendimientos de pesca, proporción sexual, así como los resultados de una evaluación directa de biomasa vulnerable mediante el método de area de influencia de las trampas. La extracción se efectuó fundamentalmente en el cuadrante NE de ambas islas, mediante botes de madera de 9,0 m de eslora. Se monitorearon 157 salidas de pesca y se capturaron 13.903 ejemplares, los cuales mayoritariamente fueron machos (97,5%. La CPUE promedio fue 16,7 ejemplares por trampa y de 13,5 ejemplares comerciales por trampa. A partir del muestreo sistemático, se detectó al recurso entre 300 y 1000 m de profundidad, con mayores rendimientos entre 400 y 500 m de profundidad (19,8 y 15,9 ejemplares por trampa. Se consideran y discuten dos escenarios de evaluación de stock para ejemplares de talla comercial en el area actualmente explotada (45,8 km , el primero estimó un radio efectivo para las trampas de 13,4 m (area de 564,1 m , con una biomasa vulnerable de 1.002 ton, equivalentes a 832.983 ejemplares, mientras que el segundo consideró un radio de 30,0 m con una biomasa vulnerable de 203 ton equivalente a 168.587 ejemplares.This work describes the artisanal golden crab (Chaceon chilensis fishery off Robinson Crusoe and Santa Clara islands in the Juan Fernández archipelago (Chile developed between July 2005 and May 2006. We report biological fishery aspects related to the físhing efforts and yields, the sexual proportion of the catch, and the results of a direct evaluation of the vulnerable biomass done using the trap area of influence method. The extraction was done mainly in the NE quadrant of both islands from wooden boats (9.0 m length. Monitoring was done during 157 f

  16. Isolation and Characterisation of a Proanthocyanidin With Antioxidative, Antibacterial and Anti-Cancer Properties from Fern Blechnum orientale

    Science.gov (United States)

    Lai, How-Yee; Lim, Yau-Yan; Kim, Kah-Hwi

    2017-01-01

    Background: Blechnum orientale Linn. (Blechnaceae), a fern, is traditionally used in the treatment of various ailments, such as skin diseases, stomach pain, urinary bladder complaints, and also as a female contraceptive. Previously, we reported a strong radical scavenging activity, antibacterial activity and cytotoxicity against HT29 colon cancer cells by aqueous extract of B. orientale. Objective: In this study, we attempted to isolate and identify the active compound from the aqueous extract of B. orientale. Materials and Methods: Aqueous extract of B. orientale was subjected to repeated MCI gel chromatography, Sephadex-LH-20, Chromatorex C18 and semi-preparative high performance liquid chromatography and was characterized using nuclear magnetic resonance and electrospray ionization mass-spectrometry spectroscopic methods. Antioxidant activity was determined using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay. Antibacterial assays were conducted using disc diffusion whereas the minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined using the broth microdilution assay. Cytotoxicity was assessed using thiazolylblue tetrazoliumbromide. Results: A polymeric proanthocyanidin consisting of 2-12 epicatechin extension units and epigallocathecin terminal units linked at C4-C8 was elucidated. Bioactivity studies showed strong radical scavenging activity (IC50 = 5.6 ± 0.1 µg/mL), antibacterial activity (MIC = 31.3-62.5 µg/mL) against five gram-positive bacteria and selective cytotoxicity against HT29 colon cancer cells (IC50 = 7.0 ± 0.3 µg/mL). Conclusion: According to our results, the proanthocyanidin of B. orientale demonstrated its potential as a natural source of antioxidant with antibacterial and anti-cancer properties. SUMMARY A bioactive proanthocyanidin was isolated from the aqueous extract of medicinal fern Blechnum orientale Linn and the structure was elucidated using NMR and ESI-MS spectral studies

  17. 长白山蕨类植物种类及开发利用探讨%The discussion of fern species and development and utilization of Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    周旭昌

    2015-01-01

    The 25 families Changbai Mountain fern plant and the morphological characteristics and application of represent-ative plant of each family was introduced.The development and utilization condition and existing problem of Changbai Mountain fern plant were pointed.The suggestion of development and utilization of Changbai Mountain fern plant was raised.%本文介绍了长白山蕨类植物25科及每科代表植物的形态特征、用途等,指出长白山蕨类植物的开发利用现状及存在问题,并对长白山蕨类植物的开发与利用提出合理建议。

  18. Biostratigraphic evidence for dramatic Holocene uplift of Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific Ocean

    Science.gov (United States)

    Sepúlveda, P.; Le Roux, J. P.; Lara, L. E.; Orozco, G.; Astudillo, V.

    2015-03-01

    Hotspot oceanic islands typically experience subsidence due to several processes related to migration of the oceanic plate away from the mantle plume and surface flexural loading. However, many other processes can interrupt subsidence, some of which may be associated with catastrophic events. A study of the biostratigraphy and sedimentology of Holocene deposits on Robinson Crusoe Island (RCI) on the Juan Fernández Ridge (JFR) indicated that dramatic uplift has occurred since 8000 years BP, at a rate of about 8.5mm yr-1. This is evidenced by supratidal flats with tepee structures and sand layers containing marine gastropods (mostly Nerita sp.) that are now exposed ca. 70 m a.s.l. The active hotspot is located 280 km further west and the last volcanic activity on RCI occurred at ca. 800 000 years BP. Long-term subsidence is evidenced by deep submerged marine abrasion terraces at RCI. As no direct evidence was found for the existence of a compensating bulge generated by the present hotspot upon which RCI would be situated, it must be concluded that subsidence in the wake of the mantle plume beneath the migrating plate was interrupted by very rapid uplift, but on a scale that did not fully compensate for the previous subsidence. This can be attributed to large-scale landslides followed by isostatic rebound, although this is only vaguely reflected in the low-resolution bathymetry of the area. To determine if this mechanism produced the uplift, a detailed bathymetric survey of the area will be required. If such a survey confirms this hypothesis, it may have implications for the short-term dynamics of vertical variations of oceanic edifices and their related effects on ecosystems and human population.

  19. Applying Fishers' ecological knowledge to construct past and future lobster stocks in the Juan Fernández Archipelago, Chile.

    Science.gov (United States)

    Eddy, Tyler D; Gardner, Jonathan P A; Pérez-Matus, Alejandro

    2010-11-05

    Over-exploited fisheries are a common feature of the modern world and a range of solutions including area closures (marine reserves; MRs), effort reduction, gear changes, ecosystem-based management, incentives and co-management have been suggested as techniques to rebuild over-fished populations. Historic accounts of lobster (Jasus frontalis) on the Chilean Juan Fernández Archipelago indicate a high abundance at all depths (intertidal to approximately 165 m), but presently lobsters are found almost exclusively in deeper regions of their natural distribution. Fishers' ecological knowledge (FEK) tells a story of serial depletion in lobster abundance at fishing grounds located closest to the fishing port with an associated decline in catch per unit effort (CPUE) throughout recent history. We have re-constructed baselines of lobster biomass throughout human history on the archipelago using historic data, the fishery catch record and FEK to permit examination of the potential effects of MRs, effort reduction and co-management (stewardship of catch) to restore stocks. We employed a bioeconomic model using FEK, fishery catch and effort data, underwater survey information, predicted population growth and response to MR protection (no-take) to explore different management strategies and their trade-offs to restore stocks and improve catches. Our findings indicate that increased stewardship of catch coupled with 30% area closure (MR) provides the best option to reconstruct historic baselines. Based on model predictions, continued exploitation under the current management scheme is highly influenced by annual fluctuations and unsustainable. We propose a community-based co-management program to implement a MR in order to rebuild the lobster population while also providing conservation protection for marine species endemic to the Archipelago.

  20. Plate tectonics and the origin of the Juan Fernández Ridge: analysis of bathymetry and magnetic patterns

    Directory of Open Access Journals (Sweden)

    Cristián Rodrigo

    2014-10-01

    Full Text Available Juan Fernández Ridge (JFR is a cα. 800 km long alignment of seamounts and islands which is thought to be fed by a deep mantle plume. JFR includes the Friday and Domingo seamounts in the western active edge close to the active hotspot, and the O'Higgins Seamount and Guyot at the eastern limit just in front of the Chile-Perú trench. Recent bathymetric (Global Topography and magnetic (EMAG-2 datasets were interpreted both qualitatively and quantitatively by means of 3D inverse modeling and 2D direct modeling for geometry and susceptibility, together with an interpretation of the synthetic anomalies related to the classical hypothesis of deep seafloor spreading. Topographic and magnetic patterns are used to understand the tectonic evolution and origin of the JFR, especially in the western segment. Results show a continuous corridor with a base at ~3900 m depth formed by four groups of seamounts/islands with a number of summits. The deep ocean floor is ~22 to ~37 Myr old and is younger to the south of the Challenger Fracture Zone that runs in a SW-NE direction. The magnetic pattern of the western JFR segment, which is different than the eastern one, has no correlation with bathymetry and does not present a common polarity nor fit with magnetic models for isolated bodies. This superposition of magnetic patterns indicates a role of the faults/fractures of the Nazca Plate. Geological evidence supports the hypothesis of a fixed mantle plume for the origin of JFR but our data suggest that tectonic processes play a role, thus fueling the global controversy about these competing processes.

  1. Global phylogeny and biogeography of the fern genus Ctenitis (Dryopteridaceae), with a focus on the Indian Ocean region.

    Science.gov (United States)

    Hennequin, Sabine; Rouhan, Germinal; Salino, Alexandre; Duan, Yi-Fan; Lepeigneux, Marie-Capucine; Guillou, Marguerite; Ansell, Steve; Almeida, Thaís Elias; Zhang, Li-Bing; Schneider, Harald

    2017-07-01

    The diverse and pantropical genus Ctenitis, in the Dryopteridaceae, has been largely ignored in phylogenetic studies until now. In this study, we fill in this gap by reconstructing the first comprehensive phylogeny of the genus including 53 species currently recognized in the genus Ctenitis, among which seven species formerly were assigned to the genus Pseudotectaria and one to Heterogonium. Special emphasis was given to the sampling of species occurring in the African-Indian Ocean region. The presented results include reconstruction of a biogeographic scenario based on estimated divergence times and ancestral area reconstruction. Our findings confirm the inclusion, within Ctenitis, of the Indian Ocean species formerly placed in Pseudotectaria and Heterogonium. The crown group divergence was estimated to date back to the Oligocene or Early Miocene. The biogeographical scenario indicates an initial divergence of the Asian-Pacific ranges and the neotropical ranges, and a subsequent colonization of the Afro-Madagascan region by a lineage with neotropical ancestors. The Afro-Madagascan lineage splits into a lineage endemic to the Mascarene islands and a lineage occurring in Madagascar, the Comoros and Africa. The range expansion towards Africa and Madagascar was estimated to date back to the late Miocene, whereas the estimated ages for the onset of the diversification of the Mascarene diversity is consistent with the ages of these young, volcanic islands. The absence of any extant species of Ctenitis with a multi-continental distribution range and the rarity of inter-island dispersal and speciation in the Indian Ocean region suggest a limited contribution of long distance dispersal to the biogeographical history of this fern genus, versus a high contribution of local speciation. Copyright © 2017. Published by Elsevier Inc.

  2. The Relationship Between Tear Ferning Patterns and Non-invasive Tear Break-up Time in Normal Asian Population.

    Science.gov (United States)

    Sharanjeet-Kaur; Ho, Chien Yee; Mutalib, Haliza Abdul; Ghazali, Ahmad Rohi

    2016-01-01

    To investigate the relationship between tear ferning patterns (TFP) and non-invasive tear break-up time (NIBUT) in normal Asian subjects. One hundred and forty-five adults with no ocular surface disorders were recruited. TFP and NIBUT were determined. Tears were collected using a capillary tube and allowed to air dry at room temperature for 10min. TFP was later observed using a light microscope and classified according to Rolando's classification. Measurement for NIBUT was obtained using a Tearscope with the slit lamp magnification. It was found that there is no significant difference between gender in TFP (Z=-1.77, P>.05) and NIBUT (Z=-1.475, P>.05). There is also no significant difference between Malay, Chinese, Indian, and other races in TFP, (H(3)=4.85, P>.05) and NIBUT (H(3)=2.18, P>.05). However, there is a significant difference between age groups of 20-29, 30-39, 40-49,and 50-60 years old in both TFP (H(3)=28.25, P<.01) and NIBUT (H(3)=36.50, P<.001). Spearman's correlation showed there was a significant relationship between TFP and NIBUT (r=-0.55, P<.001), age and NIBUT (r=-0.50, P<.001), age and TFP (r=0.41, P<.001), McMonnies score and NIBUT (r=-0.40, P<.001), McMonnies score and TFP (r=0.31, P<.001), as well as age and McMonnies score (r=0.52, P<.001). TFP and NIBUT was age dependent but not gender and race dependent. Older subjects had higher grade of TFP and McMonnies questionnaire score but lower NIBUT value. TFP and NIBUT can be used to assess the tear film quality. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  3. Developmental morphology of strap-shaped gametophytes of Colysis decurrens: a new look at meristem development and function in fern gametophytes

    Science.gov (United States)

    Takahashi, Naoko; Hashino, Mie; Kami, Chieko; Imaichi, Ryoko

    2009-01-01

    Background and Aims The gametophytes of most homosporous ferns are cordate–thalloid in shape. Some are strap- or ribbon-shaped and have been assumed to have evolved from terrestrial cordate shapes as an adaptation to epiphytic habitats. The aim of the present study was to clarify the morphological evolution of the strap-shaped gametophyte of microsoroids (Polypodiaceae) by precise analysis of their development. Methods Spores of Colysis decurrens collected in Kagoshima, Japan, were cultured and observed microscopically. Epi-illuminated micrographs of growing gametophytes were captured every 24 h, allowing analysis of the cell lineage of meristems. Light microscopy of resin-sections and scanning electron microscopy were also used. Key Results Contrary to previous assumptions that strap-shaped Colysis gametophytes have no organized meristem, three different types of meristems are formed during development: (1) apical-cell based – responsible for early growth; (2) marginal – further growth, including gametophyte branching; and (3) multicellular – formation of cushions with archegonia. The cushion is two or three layers thick and intermittent. The apical-cell and multicellular meristems are similar to those of cordate gametophytes of other ferns, but the marginal meristem is unique to the strap-shaped gametophyte of this fern. Conclusions The strap-shaped gametophytes of C. decurrens may have evolved from ancestors with a cordate shape by insertion of the marginal meristem phase between the first apical-cell-based meristem and subsequent multicellular meristem phases. Repeated retrieval of the marginal meristem at the multicellular meristem phase would result in indefinite prolongation of gametophyte growth, an ecological adaptation to epiphytic habitats. PMID:19812067

  4. Natural radionuclides in lichens, mosses and ferns in a thermal power plant and in an adjacent coal mine area in southern Brazil.

    Science.gov (United States)

    Galhardi, Juliana Aparecida; García-Tenorio, Rafael; Díaz Francés, Inmaculada; Bonotto, Daniel Marcos; Marcelli, Marcelo Pinto

    2017-02-01

    The radio-elements (234)U, (235)U, (238)U, (230)Th, (232)Th and (210)Po were characterized in lichens, mosses and ferns species sampled in an adjacent coal mine area at Figueira City, Paraná State, Brazil, due to their importance for the assessment of human exposure related to the natural radioactivity. The coal is geologically associated with a uranium deposit and has been used as a fossil fuel in a thermal power plant in the city. Samples were initially prepared at LABIDRO (Isotopes and Hydrochemistry Laboratory), UNESP, Rio Claro (SP), Brazil. Then, alpha-spectrometry after several radiochemical steps was used at the Applied Nuclear Physics Laboratories, University of Seville, Seville, Spain, for measuring the activity concentration of the radionuclides. It was (210)Po the radionuclide that most bio-accumulates in the organisms, reaching the highest levels in mosses. The ferns species were less sensitive as bio-monitor than the mosses and lichens, considering polonium in relation to other radionuclides. Fruticose lichens exhibited lower polonium content than the foliose lichens sampled in the same site. Besides biological features, environmental characteristics also modify the radio-elements absorption by lichens and mosses like the type of vegetation covering these organisms, their substrate, the prevailing wind direction, elevation and climatic conditions. Only (210)Po and (238)U correlated in ferns and in soil and rock materials, being particulate emissions from the coal-fired power plant the most probable U-source in the region. Thus, the biomonitors used were able to detect atmospheric contamination by the radionuclides monitored. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 蕨根抗性淀粉的制备工艺研究%Preparation Technology of Fern Root Resistant Starch

    Institute of Scientific and Technical Information of China (English)

    钟耕; 陈恋; 郑红艳; 张运芳

    2009-01-01

    压热法制备蕨根抗性淀粉的过程中,淀粉乳质量分数、压热温度、pH、压热时间和老化时间对蕨根抗性淀粉质量分数有不同程度的影响.通过三因素二次正交旋转组合设计,得出淀粉乳质量分数、pH、压热时间对蕨根抗性淀粉质量分数的影响大小次序为:淀粉乳质量分数>pH>压热时间.压热法制备蕨根抗性淀粉的最佳工艺条件为:淀粉乳质量分数28.7%,pH7.8,121℃压热处理38 min,4℃老化24 h,得到的蕨根抗性淀粉质量分数为10.94%.%Fern Root starch was used to prepare resistant starch.The starch concentration,autoclaving temperature,pH value,autoclaving time and retrogradation time showed different influence on fern root resistant starch yield.An experiment of three-factor and two-dimensional revolving orthogonal combinatorial design was carried out to optimize the reaction conditions.Results:The rank order of the influence factors is starch concentration>pH values>autoelaving time.The optimum preparation process for fern root resistant starch is starch concentration 28.7%,pH 7.8,heated at 121℃ for 38min,then retrograded at 4℃ for 24 h.The resistant starch content of the product is 10.94%.

  6. Cuando habla el subconsciente. Grietas de terror gótico en los cuentos de Cristina Fernández Cubas

    OpenAIRE

    López Santos, Miriam

    2013-01-01

    El presente artículo trata de descubrir las reminiscencias del gótico posmoderno que perviven en los cuentos de la escritora catalana Cristina Fernández Cubas. A través del análisis de alguno de los mismos, queda demostrado cómo los personajes, tras haber sufrido determinadas experiencias traumáticas, experimentan en la conformación de su personalidad un conflicto entre aceptar su parte abyecta, y perder su “yo” social, o fundirse con la sociedad, anulando así la parte más oscura de sí mismos...

  7. La metodología de las ciencias sociales en Manuel Sacristán y Francisco Fernández Buey

    OpenAIRE

    Sarrión Andaluz, José; López Arnal, Salvador

    2012-01-01

    Diálogo entre Salvador López Arnal, especialmente conocido por su trabajo en la recuperación y divulgación del pensamiento de Manuel Sacristán, y José Sarrión Andaluz acerca de la trayectoria y obra de dos figuras fundamentales en la filosofía y la metodología de las ciencias sociales en España; Manuel Sacristán y Francisco Fernández Buey.

  8. 甘肃省草原蕨类植物区系的研究%Study on the fern flora in grassland of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    史静; 韩天虎; 金加明; 蓝晞; 梁永良; 邓素媛; 陈本建

    2016-01-01

    为全面了解甘肃省草原蕨类植物的生长分布状况及植物区系的地理组成成分,充分研究该区域的自然历史过程,本研究在野外调查和已有资料整理的基础上,分析了甘肃省草原蕨类植物区系组成和分布区类型.研究表明,甘肃省草原共有蕨类植物14科19属31种,分别占中国蕨类植物资源(63科230属2600种)总科数的22.22%,总属数的8.26%,总种数的1.19%.优势科为鳞毛蕨科、水龙骨科;优势属为卷柏属、岩蕨属.科以热带分布型为主;属主要以热带分布型和温带分布型为主,无特有属;垂直分布较为明显;含有古老科属;甘肃省草原蕨类植物丰富程度不高.%In order to fully understand the distribution characteristics and geographical elements of fern flora and reveal their process of natural history in the Gansu Province grassland,the present study investigated the fern in this area and analysis the floristic composition and geographical distribution.The results show that there are 31 species which belong to 19 genera and 14 famlies in Gansu rangeland which accounts for 22.22% of the total family,8.26% of the total genus,1.99% of the total species of China ferns resources (63 families 230 gen-era and 2 600 species),respectively.The dominant families are Dryopteridceae and Polypodiaceae;dominant genera are Selaginella and Woodsia.The family is mainly tropical distribution type and the genus is mainly trop-ical and temperate distribution without endemic genus.Vertical distribution is obvious containing old families and genera.The richness of fern in Gansu grassland is not high.

  9. Counter-Sublime Aesthetics: Prose as a Fracture of Identity in the Travels of Leandro Fernández de Moratín

    Directory of Open Access Journals (Sweden)

    Alberto SANTAMARÍA FERNÁNDEZ

    2014-02-01

    Full Text Available The aim of this article is to analyze the works by Leandro Fernández de Moratín between 1792 and 1797 in order to show the modernity of his writing in the context of eighteenth-century European literature. During his travels the author describes sublime landscapes, but at the same time is ironic about his time and his country. Specifically, this paper analyzes the prose of Apuntaciones sueltas de Inglaterra and Viaje de Italia, as well as the modernity of a text such as Auto de fe de Logroño.

  10. Dos poetes de la primera metada del XVIII: Xuan Fernández Porléi y Nicolás Torano de la Puerta

    OpenAIRE

    Busto Cortina, Xuan Carlos

    2011-01-01

    Este artículo estudia y edita la obra en asturiano de dos poetas de la primera mitad del siglo XVIII inéditos hasta ahora: Xuan Fernández Porléi y Nicolás Torano de la Puerta. Las dos figuras vienen a cubrir un hueco temporal poco conocido en la historia literaria asturiana, entre los primeros autores del siglo XVII y la generación ilustrada de finales del XVIII. En los dos casos, se procede a un breve estudio biográfico de ambos autores y a la edición crítica anotada de las obras respectivas...

  11. Cuando habla el subconsciente. Grietas de terror gótico en los cuentos de Cristina Fernández Cubas

    OpenAIRE

    López Santos, Miriam

    2013-01-01

    El presente artículo trata de descubrir las reminiscencias del gótico posmoderno que perviven en los cuentos de la escritora catalana Cristina Fernández Cubas. A través del análisis de alguno de los mismos, queda demostrado cómo los personajes, tras haber sufrido determinadas experiencias traumáticas, experimentan en la conformación de su personalidad un conflicto entre aceptar su parte abyecta, y perder su “yo” social, o fundirse con la sociedad, anulando así la parte más oscura de sí mismos...

  12. Using combined measurements for comparison of light induction of stomatal conductance, electron transport rate and CO2 fixation in woody and fern species adapted to different light regimes.

    Science.gov (United States)

    Wong, Shau-Lian; Chen, Chung-Wei; Huang, Hsien-Wen; Weng, Jen-Hsien

    2012-05-01

    We aimed to understand the relation of photosynthetic rate (A) with g(s) and electron transport rate (ETR) in species of great taxonomic range and light adaptation capability during photosynthetic light induction. We studied three woody species (Alnus formosana, Ardisia crenata and Ardisia cornudentata) and four fern species (Pyrrosia lingus, Asplenium antiquum, Diplazium donianum and Archangiopteris somai) with different light adaptation capabilities. Pot-grown materials received 100 and/or 10% sunlight according to their light adaptation capabilities. At least 4 months after light acclimation, CO(2) and H(2)O exchange and chlorophyll fluorescence were measured simultaneously by equipment in the laboratory. In plants adapted or acclimated to low light, dark-adapted leaves exposed to 500 or 2000 µmol m(-2) s(-1) photosynthetic photon flux (PPF) for 30 min showed low gross photosynthetic rate (P(g)) and short time required to reach 90% of maximum P(g) (). At the initiation of illumination, two broad-leaved understory shrubs and the four ferns, especially ferns adapted to heavy shade, showed higher stomatal conductance (g(s)) than pioneer tree species; materials with higher g(s) had short at both 500 and 2000 µmol m(-2) s(-1) PPF. With 500 or 2000 µmol m(-2) s(-1) PPF, the g(s) for the three woody species increased from 2 to 30 min after the start of illumination, but little change in the g(s) of the four ferns. Thus, P(g) and g(s) were not correlated for all material measured at the same PPF and induction time. However, P(g) was positively correlated with ETR, even though CO(2) assimilation may be influenced by stomatal, biochemical and photoinhibitory limitations. In addition, was closely related to time required to reach 90% maximal ETR for all materials and with two levels of PPF combined. Thus, ETR is a good indicator for estimating the light induction of photosynthetic rate of species, across a wide taxonomic range and light adaptation and acclimation

  13. Espiritualidad e inquisición en Asturias en el siglo XVIII: El proceso del Obispo José Fernández de Toro

    OpenAIRE

    Tuñón Escalada, Juan José

    2014-01-01

    La investigación realizada profundiza en el estudio de la diócesis de Oviedo en el primer tercio del siglo XVIII, un periodo escasamente abordado por la historiografía. Analiza el complejo y controvertido episcopado ovetense de José Fernández de Toro, tardío pero significativo exponente de la difusión alcanzada en España por Miguel de Molinos y su Guía Espiritual. Estudia minuciosamente y saca a la luz el singular, y prácticamente inédito, proceso inquisitorial seguido contra el obispo oveten...

  14. First Harvestman Record for the Juan Fernández Archipelago, Chile, with Morphological Notes on Acropsopilio chilensis (Opiliones: Caddidae: Acroposopilioninae).

    Science.gov (United States)

    Pérez-González, Abel; Ramírez, Martín J; Soto, Eduardo M; Pizarro-Araya, Jaime

    2014-08-15

    Acropsopilio chilensis Silvestri, 1904 (Eupnoi: Caddidae: Acropsopilioninae), is recorded for Robinson Crusoe Island, Chile. This is the first harvestman species recorded for the Juan Fernández Archipelago and also the first extra-continental record for this species. During the comparison with continental co-specific specimens, some previously unknown, remarkable morphological characteristics were discovered, among them: the absence of ovipositor seminal receptacles and tracheal system, small and probably imperforate spiracles and the presence of a subdistal spiny structure, maybe a stylus, in the major branch of the penis. 

  15. 马蹄蕨黄酮的纯化及抗氧化活性研究%Purification of Horseshoe fern Flavonoids and Studies on its Antioxidant Activity

    Institute of Scientific and Technical Information of China (English)

    江明珠; 颜辉; 闻燕

    2011-01-01

    [Objective] The aim was to purify Horseshoe fern flavonoids and study its antioxidant activity. [ Method ] Flavonoids were extracted from Horseshoe fem under the conditions of ethanol concentration 70% , material/liquid 1 : 40, ultrasonic power 140 W and extracting time 1 h. The optimal isolation and purification technology of Horseshoe fern flavonoids was studied by taking adsorption capacity and desorption rate as indexes. Furthermore,the antioxidant activity of orseshoe fern flavonoids was studied by deter mining their clear ability about DPPH radicals and OH radi cals and their reductive ability. [Result] The AB-8 macroporous resin showed the best adsorption and desorption ability comparing with the other seven kind of macroporous resins, and the purity of flavonoid reached 40.6%. Total flavonoids of Horseshoe fem had strong antioxidant activity. The antioxidant activity of Horseshoe fem flavonoids was positively correlated with the concentration within a certain range. [Conclusion] The re search provides theoretical basis for the comprehensive development and utilization of Horseshoe fern resources.%[目的]纯化马蹄蕨黄酮并研究其抗氧化活性.[方法]在以70%乙醇为溶剂、料液比1∶40、超声时间1h、超声功率140W的条件下提取了马蹄蕨黄酮;以吸附量和解析率为指标研究了分离纯化马蹄蕨黄酮的最佳工艺;并通过测定还原能力、清除DPPH和羟自由基能力研究了所得黄酮的抗氧化活性.[结果]AB-8树脂的纯化效果最好,黄酮纯度达40.6%;马蹄蕨黄酮具有较强的抗氧化活性,一定范围内抗氧化活性和浓度呈正相关.[结论]为马蹄蕨资源的综合开发利用提供了理论依据.

  16. Cruces, mestizaje y dislocación en la escritura de Enrique Vila-Matas, Augusto Monterroso y Macedonio Fernández

    OpenAIRE

    Paruolo, Ana María

    2008-01-01

    La presente exposición es parte de una investigación sobre la obra de Augusto Monterroso y se relaciona con mi proyecto de tesis de Doctorado, actualmente en curso. En el marco del I Congreso Internacional de Literatura y Cultura Españolas Contemporáneas, se ha pensado examinar los cruces e intersecciones que tienen lugar en y desde la escritura de Enrique Vila-Matas, Augusto Monterroso y Macedonio Fernández. Se utilizará para la indagación la siguiente metodología de trabajo: búsqueda, selec...

  17. Resource Distribution and Exploitation of Edible Ferns in Guizhou (Ⅱ)%贵州食用蕨类植物资源分布及开发利用(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    云雪林; 赵能武; 潘炉台; 赵俊华

    2009-01-01

    对其余41种贵州食用蕨类植物区系组成特点及资源分布进行阐述,并对贵州食用蕨类资源的合理开发利用提出了相应的政策建议.%The floristic composition characters and resource distribution of other 41 kinds of the edible ferns in Guizhou are described. The study puts forward some policy suggestions on reasonably exploiting the resource of edible ferns in Guizhou.

  18. 光照强度对5种观赏蕨生理指标的影响%Effects of Light Intensity on Physiological Indexes of Five Ornamental Ferns

    Institute of Scientific and Technical Information of China (English)

    张国珍; 曾富春; 李策宏; 谢孔平

    2014-01-01

    The aim was to study the physiological response of 5 kinds of ornamental fern on Mt. Emei to light. [Method] Five native ornamental ferns (Polystichum omeiense, Plagiogyria adnata, Bolbitis heteroclite, Pyrrosia calvata and Pteris multifida) collected from Mt.Emei were tested under four level of shade degree (0%、30%、50%、83%of full sunlight), and the variation of physiological indexes of every ferns under different light intensity treatments were studied. [Result] The results showed that Chlorophyll(Chl) contents and chla/b ratio of ornamental ferns were influenced greatly by illumination intensity. As the illumination intensity weakening, Chl contents of all ferns increased and Chla/b ratio reduced. And the fern with higher Chl content and lower Chla/b ratio could live under weak light. The proline contents and MDA contents of all ferns increased constantly under light intensity stress, while the soluble protein contents decreased. The POD enzyme activity of ornamental ferns increased under light intensity stress. And the enzymatic activity of POD and it’s variation of ferns were positively correlated with their endurance abilities to light stress. According to the physiological responses to light stress of five tested ornamental ferns, the order for the shade-tolerance of them was Pteris multifida>Bolbitis heteroclita>Polystichum omeiense>Plagiogyria adnata>Pyrrosia calvata. [Conclusion] The results provided references for development and application of ornamental fern .%[目的]探讨峨眉山5种观赏蕨对不同光照的生理响应。[方法]以峨眉山5种优良观赏蕨类峨眉耳蕨、瘤足蕨、长叶实蕨、光石韦和井栏边草为试验材料,设置全光照、遮阴30%、遮阴50%、遮阴83%共4个光照梯度,探讨不同光照强度对5种观赏蕨生理指标的影响。[结果]光照强度对观赏蕨叶绿素a、b及叶绿素总量影响较大,在一定光照范围内,叶绿素总量随着光照强度降低而

  19. LA PALABRA DIBUJADA. ANTONIO FERNÁNDEZ-ALBA, PRIMER Y ÚLTIMO MAESTRO / The drawn word. Antonio Fernández-Alba, first and last master

    Directory of Open Access Journals (Sweden)

    Juan Luis Trillo de Leyva

    2015-05-01

    Full Text Available Távora y Fernández-Alba son figuras de referencia ineludible para quienes quieran hoy investigar el origen contemporáneo de la arquitectura peninsular y, sobre todo, de sus escuelas. Alba fue siempre una guía para los que abordamos una enseñanza alejados del aura que acompañaba a los grandes arquitectos madrileños y barceloneses. Su experimentación didáctica alteró la trayectoria de las escuelas de arquitectura españolas. Introdujo la cultura contemporánea en la universidad como si se tratara de una segunda naturaleza, de un nuevo estrato territorial de los proyectos, manteniendo al hombre como objeto central y destinatario de todo proceso proyectual. En época de virtualidad y representación automatizada, nada más adecuado que la revisión de los dibujos del maestro Fernández-Alba. Dibujos que requieren ser proyectados, pensados, antes que ejecutados, “proyectos de proyectos”, una especie de tautología que rige la mente del poeta en su continua reducción, compresión o destilación, gota a gota, del mundo real, del universo y la palabra.

  20. The effects of fragmentation on Araucaria forest: analysis of the fern and lycophyte communities at sites subject to different edge conditions

    Directory of Open Access Journals (Sweden)

    Vinícius Leão da Silva

    2015-06-01

    Full Text Available Edge effects impact species richness and composition as a result of environmental changes caused by fragmentation. This study analyzed edge effects on a community of terrestrial ferns and lycophytes in an Araucaria forest in Brazil at sites subjected to differing edge conditions: (1 a site bordering a road running through the interior of a conservation unit, and (2 a site bordering an agricultural property. Twelve 10 × 10 m plots were selected at the edge and in the interior of each site, and accounted for a total of 48 plots. The edges had lost their characteristic floristic identity, suggesting that many species are sensitive to variations in environmental conditions. The edge effect had a negative impact on species richness as shown by the greater average numbers of fern and lycophyte species in forest interiors at both sites. The results showed that the forest fragments in contact with agricultural areas were subjected to more intense edge effects than the fragments bordering a road within a conservation unit.

  1. Lycophytes and ferns composition of Atlantic Forest conservation units in western Paraná with comparisons to other areas in southern Brazil

    Directory of Open Access Journals (Sweden)

    Mayara Lautert

    2015-12-01

    Full Text Available This study surveyed lycophyte and fern species in four forest fragments in western Paraná, Brazil, and compared them to 15 other fragments with different plant formations from the Atlantic Forest biome in southern Brazil. In total, five lycophyte species (in two families and two genera and 98 species and two varieties of ferns (in 16 families and 38 genera were registered in the four fragments. The most represented families were Pteridaceae (23 spp., Polypodiaceae (18 spp., Aspleniaceae (13 spp., and Thelypteridaceae (11 spp.. Asplenium (12 spp., Thelypteris (10 spp., and Blechnum (seven spp. were among the most represented genera. The occurrence of Dicksonia sellowiana was noteworthy because it was associated with seasonal semideciduous forest and is threatened in Brazil. Similarity among areas was determined by a cluster analysis (UPGMA and Sørensen’s index and the relation between similarity and geographic distance was determined through Matel’s analysis. The analyses revealed greater similarity among the four study areas and, for these areas as a whole, greater similarity to fragments in Rio Grande do Sul, which is evidence that these areas have similar environmental conditions.

  2. Stomatal dynamics are limited by leaf hydraulics in ferns and conifers: results from simultaneous measurements of liquid and vapour fluxes in leaves.

    Science.gov (United States)

    Martins, Samuel C V; McAdam, Scott A M; Deans, Ross M; DaMatta, Fábio M; Brodribb, Tim J

    2016-03-01

    Stomatal responsiveness to vapour pressure deficit (VPD) results in continuous regulation of daytime gas-exchange directly influencing leaf water status and carbon gain. Current models can reasonably predict steady-state stomatal conductance (gs ) to changes in VPD but the gs dynamics between steady-states are poorly known. Here, we used a diverse sample of conifers and ferns to show that leaf hydraulic architecture, in particular leaf capacitance, has a major role in determining the gs response time to perturbations in VPD. By using simultaneous measurements of liquid and vapour fluxes into and out of leaves, the in situ fluctuations in leaf water balance were calculated and appeared to be closely tracked by changes in gs thus supporting a passive model of stomatal control. Indeed, good agreement was found between observed and predicted gs when using a hydropassive model based on hydraulic traits. We contend that a simple passive hydraulic control of stomata in response to changes in leaf water status provides for efficient stomatal responses to VPD in ferns and conifers, leading to closure rates as fast or faster than those seen in most angiosperms.

  3. Comerse las Indias. La alimentación como clave clasificatoria del Nuevo Mundo en la obra de Fernández de Oviedo

    Directory of Open Access Journals (Sweden)

    Egaña Rojas, Daniel

    2015-12-01

    Full Text Available The description of nature in Gonzalo Fernández de Oviedo’s work has been studied as the beginning of the research on the natural history of the New World, which a closer reading makes it possible to link to other disciplinary fields. In this article, it is suggested that Oviedo was approaching its nature with the aim of placing the New Continent within the context of the spice trade, from where it had been removed at the end of the 15.th century.Aunque la descripción de la naturaleza del Nuevo Mundo en la obra de Gonzalo Fernández de Oviedo ha sido estudiada como la precursora de la historia natural indiana, una lectura detallada evidencia otras genealogías posibles. El artículo plantea que, antes que una historia natural, la naturaleza es vista y clasificada por Oviedo a partir de un criterio alimentario, intentando volver a situar las Indias en la ruta de las especias, de la que habían sido apartadas a fines del siglo XV.

  4. Señorío y realengo. A propósito de la curaduría de don Alonso Fernández de Lugo

    Directory of Open Access Journals (Sweden)

    Ana Viña Brito

    2013-11-01

    Full Text Available El desempeño de la curaduría por parte de don Alonso Fernández de Lugo sobre los hijos de su esposa, don Guillén y doña Inés, le permitió la intervención directa en las islas de señorío y actuar como «señor de vasallos». Se analizan los antecedentes y consecuencias que tuvo la curaduría tanto para el Adelantado como para los Peraza.The Adelantado don Alonso Fernández de Lugo filled the office of the «curaduría» which entrusted him with the care over the offspring of don Guillén and doña Inés. This entitled him to free intervention in those islands of lordly demesne and gave him the chance to act as a «lord of vassals». This paper analyses the precedents and consequences of this curaduría both for the Adelantado and for the Peraza household.

  5. Ability of the aquatic fern Azolla to remove chemical oxygen demand and polyphenols from olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Sacchi, Angelo

    2007-03-01

    Full Text Available We investigated the biofiltration ability of the aquatic fern Azolla to remove polyphenols and chemical oxygen demand (COD from olive mill wastewater (OMWw collected from the traditional (TS and continuous (CS extraction systems. Azolla biomass was packed into five sequential Imhoff cones and five sequential columns. In both experiments, the filtrates collected from the 5th biofilter showed a decrease in polyphenol contents: from 7650 mg l–1 to 3610 mg l–1 in TS OMWw and from 3852 mg l–1 to 1351 mg l–1 in CS OMWw. The COD contents decreased from 110200 mg L–1 to 52400 mg L–1 in TS OMWw and from 41600 mg L–1 to 2300 mg L–1 in CS OMWw. A 5:1 OMWw to Azolla-fresh-weight ratio was optimal for both polyphenol and COD removal. The biofiltration ability of alfalfa was compared with that of Azolla, but the treatment with alfalfa did not result in the reduction of COD or polyphenols.La eficacia del helecho de agua azolla para eliminar polifenoles y reducir la demanda química de oxígeno (DQO de los alpechines obtenidos en el proceso de obtención tradicional y continuo del aceite de oliva, fue investigado mediante ensayos de filtración. Cinco conos secuenciales de Imhoff y cinco columnas secuenciales se rellenaron de biomasa de Azolla. En ambos experimentos, el filtrado procedente de la quinta extracción mostró una disminución en el contenido de polifenoles de 7650 mg L–1 a 3610 mg L–1en el alpechín obtenido mediante el sistema tradicional y de 3852 mg L–1 a 1351 mg L–1en el alpechín del sistema continuo. La demanda química de oxígeno del alpechín del sistema tradicional disminuyó de 110200 mg L–1 a 52400 mg L–1 en y de 41600 mg L–1a 2300 mg L–1en el procedente del sistema continuo. Una proporción en peso 5:1 de alpechín: Azolla fue la óptima tanto para la reducción de los polifenoles como para la de la DQO. La eficiencia del tratamiento biológico con alfalfa se comparó con la obtenida con Azolla. Los

  6. Structural differences between light and heavy rare earth element binding chlorophylls in naturally grown fern: Dicranopteris linearis.

    Science.gov (United States)

    Wei, Zhenggui; Hong, Fashui; Yin, Ming; Li, Huixin; Hu, Feng; Zhao, Guiwen; Wong, Jonathan Woonchung

    2005-09-01

    Chloroplasts and chlorophylls were isolated from the leaves of Dicranopteris linearis, a natural perennial fern sampled at rare earth element (REE) mining areas in the South-Jiangxi region (southern China). The inductively coupled plasma-mass spectrometry (ICP-MS) results indicated that REEs were present in the chloroplasts and chlorophylls of D. linearis. The in vivo coordination environment of light REE (lanthanum) or heavy REE (yttrium) ions in D. linearis chlorophyll-a was determined by the extended X-ray absorption fine structure (EXAFS). Results revealed that there were eight nitrogen atoms in the first coordination shell of the lanthanum atom, whereas there were four nitrogen atoms in the first coordination shell of yttrium. It was postulated that the lanthanum-chlorophyll-a complex might have a double-layer sandwich-like structure, but yttrium-binding chlorophyll-a might be in a single-layer form. Because the content of REE-binding chlorophylls in D. linearis chlorophylls was very low, it is impossible to obtain structural characteristics of REE-binding chlorophylls by direct analysis of the Fourier transform infrared (FTIR) and ultraviolet (UV)-visible spectra of D. linearis chlorophylls. In order to acquire more structural information of REE-binding chlorophyll-a in D. linearis, lanthanum - and yttrium-chlorophyll-a complexes were in vitro synthesized in acetone solution. Element analyses and EXAFS results indicated that REE ions (lanthanum or yttrium) of REE-chlorophyll-a possessed the same coordination environment whether in vivo or in vitro. The FTIR spectra of the REE-chlorophyll-a complexes indicated that REEs were bound to the porphyrin rings of chlorophylls. UV-visible results showed that the intensity ratios of Soret to the Q-band of REE-chlorophyll-a complexes were higher than those of standard chlorophyll-a and pheophytin-a, indicating that REE-chlorophyll-a might have a much stronger ability to absorb the ultraviolet light. The MCD spectrum in

  7. Island mass effect in the Juan Fernández Archipelago (33°S), Southeastern Pacific

    Science.gov (United States)

    Andrade, Isabel; Sangrà, Pablo; Hormazabal, Samuel; Correa-Ramirez, Marco

    2014-02-01

    Spatial and temporal variability of the island mass effect (IME; defined as local increases of phytoplankton associated with the presence of islands) at the Juan Fernández Archipelago (JFA) is analyzed using chlorophyll-a (Chl-a) satellite data, altimetry, sea surface temperature, wind, geostrophic currents and net heat flux over a ten year period (2002-2012). The the JFA islands (Robinson Crusoe-Santa Clara (RC-SC) and Alejandro Selkirk (AS)) present wakes with significant Chl-a increases, mainly during spring time. These wakes can reach Chl-a values of one order of magnitude higher (~1 mg m-3) than the surrounding oligotrophic waters (<0.1 mg m-3). The wakes are similar to von Kármán vortex streets which have been used to explain the impact of IME on Chl-a increases in numerical models. The wakes are formed from a high productivity area in the lee of the island, extending to the oceanic region as high Chl-a patches associated with submesoscale eddies that are detached from the islands and connected by less-productive zones. This pattern coincides with previous models that predict the effects of island-generated flow perturbations on biological production variability. The IME is a recurrent feature of islands that has even been observed in decadal average fields. In such average fields, the Chl-a values in RC-SC and AS islands can exceed values found in a Control Zone (a zone without islands) by ~50% and 30%, respectively. Seasonal and interannual variability reveals that, as a consequence of the IME, the winter Chl-a maximum associated with the development of winter convection and mesoscale eddies that propagate from the continental zone, promote that the Chl-a maximum extends towards spring. The IME has an impact on the island on both a local as well as a more regional scale that affects an area of ~40,000 km2 (1°Latitude×4°Longitude) centered on the islands. The transport of high productivity patches associated with submesoscale eddies may be responsible

  8. New additions to the introduced flora of the Juan Fernández Islands: origin, distribution, life history traits, and potential of invasion Nuevas adiciones a la flora introducida de las Islas Juan Fernández: origen, distribución, rasgos de historia de vida y potencial de invasión

    Directory of Open Access Journals (Sweden)

    JAIME G. CUEVAS

    2004-09-01

    Full Text Available Oceanic islands, such as Juan Fernández in Chile, are the home for particular biotas that have evolved in isolation over a long period. The anthropogenic introduction of allochtonous plants is one of many problems for the conservation of endemic elements. In this paper, we present the new additions to the introduced flora of the Juan Fernández Islands, adding some comments about their life form, origin, morphological characteristics, ecology, distribution, abundance, and their potential of invasion. We cited 27 new species, 12 new genera, and three new families for the Juan Fernández flora (Amaryllidaceae, Commelinaceae and Violaceae. Most genera belonged to Asteraceae (seven species. Fifty-nine percent of taxa were perennial herbs, followed by annual or biennial herbs. Wind was the main vector of propagule dispersal (42 %, followed by vegetative dispersal (23 %. Fifty-two percent of the species were weeds and 44 % were plants with dual behaviour: garden-weed plant. Eurasia was the most frequent area of plant origin (70 %. Ninety-four percent of the taxa with known geographic range are in the V Region of mainland Chile, which is the main region of export of plants and materials to the archipelago, suggesting that this may have been the immediate origin of these introductions. Sixty-three percent of the species were only found in the San Juan Bautista urban area, while the remaining taxa were also (22 % or exclusively (15 % found in other places of the main island (Robinson Crusoe. Sixteen species (59 % are considered as noxious weeds in Juan Fernández or elsewhere, and they should be a focus of attention and, eventually, control. Summing our findings to previous lists of introduced taxa, we obtained 260 non-native taxa in Juan Fernández. This number is greater than the native taxa (211, which demonstrate how the human intentional and non-intentional action can dramatically change the floristic composition of an oceanic archipelago. We

  9. Market Basket Analysis: a new tool in ecology to describe chemical relations in the environment--a case study of the fern Athyrium distentifolium in the Tatra National Park in Poland.

    Science.gov (United States)

    Samecka-Cymerman, Aleksandra; Stankiewicz, Andrzej; Kolon, Krzysztof; Kempers, Alexander J; Leuven, Rob S E W

    2010-09-01

    In this study, the novel data mining technique Market Basket Analysis (MBA) was applied for the first time in biogeochemical and ecological investigations. The method was tested on the fern Athyrium distentifolium, in which we measured concentrations of the elements Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn. Plants were sampled from sites with different types of bedrock in the Tatra National Park in Poland. MBA was used to investigate whether specimens of Athyrium distentifolium that contain elevated levels of certain elements occur more frequently on a specific type of bedrock and to identify relationships between the type of bedrock and the concentrations of the elements in this fern. The results were compared with those of the commonly used principal component and classification analysis (PCCA) technique. MBA and PCCA ordination both yielded distinct groups of ferns growing on different types of bedrock. Although the results of MBA and PCCA were similar, MBA has the advantage of being independent of the size of the data set. In addition, MBA revealed not only dominant elements but, in the case of limestone bedrock, also showed very low concentrations of Cd, Fe, Mn, and Pb in ferns growing on this type of parent material. MBA, thus, appeared to be a promising data mining method to reveal chemical relations in the environment as well as the accumulation of chemical elements in bioindicators. This technique can be used to reveal associations and correlations among items in large data sets collected on a national or even larger scale.

  10. An Analysis of the Degree of Importance of Plant Families in the Medicinal Ferns of Guangxi Zhuang Autonomous Region%广西药用蕨类植物所在科的重要度分析

    Institute of Scientific and Technical Information of China (English)

    刘金标; 卢家仕; 黄敏; 宋日云

    2008-01-01

    The study was undertaken to determine the degree of importance of plant families in the medicinal ferns of Guangxi Zhuang Autonomous Region, China. A regression residual analysis was carried out on the number of medicinal ferns and the total number of ferns in each family for 56 fern families in the region. According to the residual values the 56 families were divided into 31 high use families and 25 low use families.%旨在确定广西药用蕨类植物所在各科的重要程度,用回归残差分析法对该地区56科蕨类植物中各科的植物种数和药用植物种数之间的关系进行了分析,根据残差值将56科分成31个高利用科和25个低利用科.

  11. Alonso Fernández de Avellaneda, Segundo Tomo de El ingenioso hidalgo Don Quijote de la Mancha, eds. M. Rodríguez Cáceres y F.B. Pedraza Jiménez

    Directory of Open Access Journals (Sweden)

    Alfredo Rodríguez López-Vázquez

    2015-01-01

    Full Text Available Reseña de Alonso Fernández de Avellaneda, Segundo Tomo de El ingenioso hidalgo Don Quijote de la Mancha, eds. M. Rodríguez Cáceres y F.B. Pedraza Jiménez, Diputación de Ciudad Real, Ciudad Real, 2014, 420 pp. ISBN: 9788477893097.

  12. Fernán González y Guzmán el Bueno en algunos escenarios españoles en la segunda mitad del siglo XIX

    OpenAIRE

    Romera Castillo, José

    2014-01-01

    El objetivo de este trabajo es constatar la presencia que dos personajes medievales (Fernán González y Guzmán el Bueno) tuvieron en espectáculos teatrales en 12 ciudades españolas en la segunda mitad del siglo XIX, cuyas carteleras han sido estudiada

  13. Resource status of wild ferns in the Baicaowa Natural Reserve and protection countermeasures%白草洼自然保护区野生蕨类植物资源现状及保护对策

    Institute of Scientific and Technical Information of China (English)

    湛礼; 王树国

    2012-01-01

    The ferns in the Baicaowa Nature Reserve in Luanping County, Hebei, China refer to 16 families, 28 genera and 58 species. Nearly all the ferns are of officinal values. Generally, ferns grow in the darkness environment including low-lying place, deep valley, underwood, stone slot, etc. Along with the development of tourism, much human interference to the environment together with the accelerated worldwide drying get the wetland area shrunk, which brings about a serious threat to the fern growing environment. In this paper, ferns protection countermeasures such as designating protection region, legislation for wilding protection, systematic protection, etc are put forward based on the situation of the reserve and its protection status so as to realize the furthest protection of the wide plants.%白草洼省级自然保护区野生蕨类植物资源共有16科28属58种,这些蕨类植物大多有药用价值.蕨类植物一般都生存在低洼、深沟、林下、石缝等靠近水源的阴湿环境中,随着森林旅游业的发展,人为活动侵入和扩展,再加之世界范围内环境干旱加剧,造成湿地环境逐渐减少和萎缩,这给蕨类植物生存构成了极大威胁.针对保护区的现状,提出了保护对策,即通过科学划定保护区域、野生植物立法、实施系统保护等措施,最大限度地实现保护区保护野生植物资源的功效.

  14. The Progress in Study on Development of Fern Gametophytes and Differentiation of Sex Organ%蕨类植物配子体发育及其性器官分化的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘建武; 刘宁

    2001-01-01

    作者概述了蕨类植物生活周期中不同发育阶段的特点,并着重介绍了光、植物生长调节物质、水和温度等因素对蕨类植物配子体发育的影响以及成精子囊素、光、钙离子和其它植物生长调节物质在性器官形成和分化过程中的作用。同时作者对蕨类植物性器官分化的不稳定性进行了探讨、并结合目前蕨类植物性器官分化的遗传学和分子生物学研究的最新进展,说明蕨类植物作为研究系统在植物生物学研究领域中的优势。%In this paper the authors reviewed the characteristics in the different phases in the life cycle of ferns. Special attentions were given to the effect of light, plant growth regulators, water and temperature on the fern gametophyte development, and the effect of antheridiogen, light, calcium and other plant growth regulator on the formation and differentiation of fern sex organ. The labile sex expression in ferns was also discussed. In the light of the latest genetic and molecular biological research, we concluded that the ferns are suitable subjects for the purpose of biological study on plants.

  15. Cultivo de Cattleya Lindley (Orchidaceae em substratos alternativos ao xaxim = Alternative substrates for Cattleya (Orchidaceae cultivation to substitute the tree fern fiber

    Directory of Open Access Journals (Sweden)

    Jorge Kaoro Yamakami

    2006-10-01

    Full Text Available Este trabalho teve como objetivo avaliar substratos alternativos ao xaxim no cultivo de um híbrido de Cattleya Lindley. Os substratos avaliados foram: xaxim; fibra de coco; casca de pínus + casca de arroz carbonizada (1:1v/v; casca de pínus+casca de arroz carbonizada (2:1v/v; casca de pínus+casca de arroz carbonizada (1:2v/v; casca de pínus e casca de arroz carbonizada. As mudas foram cultivadas em vasos de polipropileno, permanecendo em viveiro com 70% de luminosidade Os parâmetros avaliados um ano após o início do experimento foram: massa de matéria fresca total, altura da parte aérea, comprimento do pseudobulbo, comprimento da maior raiz, número de raízes, número de brotos, número de flores, pH e condutividade elétrica. O substrato constituído de fibra de coco proporcionou bons resultados, podendo ser considerado alternativo ao xaxim no cultivo deCattleya.The objective of this study was to evaluate alternative substrates tosubstitute tree fern fiber for cultivation of hybrids from the Cattleya species. Seedlings were cultivated in polypropylene vases, kept in screen shadowed nursery by a 70% of lighting. The following substrates were evaluated: tree fern fibers; coconut fiber; pinus bark+carbonized rice hull (1:1 v/v; pinus bark+carbonized rice hull (2:1 v/v; pinus bark+carbonized rice hull (1:2 v/v; pinus bark and carbonized rice hull. One year after the experiment, the followingparameters were evaluated: fresh matter mass, aerial part height, pseudobulb length, greater root length, number of buds, number of flowers, pH and electric conductivity. The substrate composed of coconut fiber showed better results, and can be used as the alternative substrate to tree fern fiber in the cultivation of Cattleya.

  16. El lugar del MERCOSUR en Ia política exterior argentina durante los gobiernos de Néstor Kirchner y Cristina Fernández de Kirchner

    OpenAIRE

    Zelicovich, Julieta

    2011-01-01

    El presente trabajo indaga acerca de cuál ha sido el lugar que los gobiernos de Néstor Kirchner y Cristina Fernández de Kirchner le han dado al MERCOSUR dentro de sus diseños de política exterior. Lo que aquí sostendremos es que el lugar que el MERCOSUR ocupe en la política exterior va a depender de cuál sea la estrategia de inserción que se adopte. Dentro de ello serán claves dos dimensiones: por un lado, el grado de congruencia entre los objetivos de la política exterior y los objetivos asi...

  17. El comentario de textos en secundaria: ejemplo de la estructura del Poema de Fernán González.

    Directory of Open Access Journals (Sweden)

    José Soto Vázquez.

    2008-01-01

    Full Text Available El comentario de textos es un arma educativa de primera mano, pues implica la lectura del texto y ayuda a su comprensión. Todas las tendencias didácticas relativas a la literatura lo contemplan como el medio más directo de acercamiento a los autores. Sin embargo, el escaso tiempo que en primero de bachillerato dedica el currículo oficial a la literatura medieval, unido al distanciamiento entre el alumno y los usos lingüísticos de la época conlleva problemas de interpretación de este tipo de textos. Por ello, nuestro trabajo pretende acercar al alumno la visión de un texto concreto, Poema de Fernán González, señalando en él las divisiones internas que lo componen, así como las diferentes versiones que del poema puede consultar en la actualidad.

  18. Mulching to regenerate a harsh site: Effect on douglas-fir seedlings, forbs, grasses, and ferns. Forest Service research paper (Final)

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P.M.; Fiddler, G.O.; Harrison, H.R.

    1994-09-01

    Douglas-fir seedlings on the Arcata District, Bureau of Land Management, U.S. Department of the Interior, in central coastal California, were planted in an effort to restore the natural forest to what was then pastureland. Douglas-fir seedlings were released from a complex forb-gass-fern plant community by applying very large (10-ft square) and very small (2-foot square) durable mulches one month after planting. In spite of high cost, the promising role of large mulches for establishing fast-growing Douglas-fir seedlings on a harsh site and the increased stability and sustainability that the future trees will bring to the more natural plant community give large mulches a place in the toolkit of ecosystem managers.

  19. Athyrium haleakalae (Athyriaceae), a new rheophytic fern species from East Maui, Hawaiian Islands: with notes on its distribution, ecology, and conservation status

    Science.gov (United States)

    Wood, Kenneth R.; Wagner, Warren L.

    2017-01-01

    Abstract Athyrium haleakalae K.R. Wood & W.L. Wagner (Athyriaceae), a small lithophytic fern from East Maui, Hawaiian Islands, is described and illustrated. Notes on its distribution, ecology, and conservation status are also presented. The new species appears to be an obligate rheophyte, preferring sites of fast moving water along concave walls of streams and waterfalls. Athyrium haleakalae differs from the only other known Hawaiian Athyrium, Athyrium microphyllum (Sm.) Alston, in having rhizomes 1–3 cm long and lanceolate blades 1- to 2-pinnate-pinnatifid, 3–8(–11) × 1–3(–4) cm, as compared to Athyrium microphyllum having rhizomes (10–)15–30 cm long and ovate to ovate-triangular blades 3-pinnate-pinnatifid to 4-pinnate, 30–82 × 20–50 cm. PMID:28228689

  20. Studies on phytoremediation of copper using Pteridium aquilinum (bracken fern) in the presence of biostimulants and bioassay using Clarias gariepinus juveniles.

    Science.gov (United States)

    Olaifa, Flora Eyibio; Omekam, Anamese Jennifer

    2014-01-01

    A study was carried out to evaluate the uptake of copper from water containing 10 mg/L copper by Pteridium aquilinum (bracken fern) and Clarias gariepinus in the presence of five plant growth stimulants: Nitrogen: phosphorus: potassium (15-15-15: an inorganic fertilizer), pig, cattle, poultry, and a mixture of pig/cattle manures. A plant growth stimulant differentiated each treatment. A 96-hour bioassay using C. gariepinus was carried out at the end of the experiment to test the efficacy of the clean up by P. aquilinum. The control experiment contained no copper or plant growth stimulant. Fish survival, uptake of copper by P. aquilinum, C. gariepinus, concentration of copper in water, hematology and histopathology of the fish were assessed. Higher concentrations of copper were reported in P. aquilinum than in water or C. gariepinus. Low fish mortality was reported with the highest being 20% in the cattle manure-containing treatment.