Pteridophytes Research Articles

Stomatal frequency and gas exchange differs in two Blechnum species (Pteridophyta, Blechnaceae) with contrasting ecological breadth

En el bosque templado de Chile, el helecho Blechnum chilense se encuentra principalmente en lugares abiertos y soleados, mientras que el helecho Blechnum mochaenum esta restringido a lugares sombrios. En este estudio se evalua si ambas especies de Blechnum, de lugares abiertos y sombreados, se comportan de manera similar respecto de sus rasgos anatomicos y fisiologicos, y si existe diferencia en la correlacion entre estos rasgos. Se midio la tasa fotosintetica maxima (Amax), conductancia estomatica (gs), evapotranspiracion (E) y SLA (area foliar especifica) in situ en 20 individuos de cada especie de helecho. Adicionalmente, se estimo la densidad estomatica (SD), el indice estomatico (SI) y el tamano de los estomas en hojas de cada individuo muestreado. Blechnum mochaenum, la especies sombra-tolerante, presento menor SD, SI, Amax y E, y mayor tamano de estomas y SLA que B. chilense. Una frecuencia estomatica mayor podria resultar en una mayor tasa de intercambio de gases en los sitios abiertos para B. chilense. La fisiologia de las hojas de estas especies de helechos parece depender, en parte, de las caracteristicas estomaticas.

Widespread impact of horizontal gene transfer on plant colonization of land.

In complex multicellular eukaryotes such as animals and plants, horizontal gene transfer is commonly considered rare with very limited evolutionary significance. Here we show that horizontal gene transfer is a dynamic process occurring frequently in the early evolution of land plants. Our genome analyses of the moss Physcomitrella patens identified 57 families of nuclear genes that were acquired from prokaryotes, fungi or viruses. Many of these gene families were transferred to the ancestors of green or land plants. Available experimental evidence shows that these anciently acquired genes are involved in some essential or plant-specific activities such as xylem formation, plant defence, nitrogen recycling as well as the biosynthesis of starch, polyamines, hormones and glutathione. These findings suggest that horizontal gene transfer had a critical role in the transition of plants from aquatic to terrestrial environments. On the basis of these findings, we propose a model of horizontal gene transfer mechanism in nonvascular and seedless vascular plants.

Can classifications of functional gender be extended to all land plants?

Abstract Land plants (bryophytes, seedless vascular plants and seed plants) may have combined or separate sexes, and this variation also may occur at two life-cycle stages. Thus plants show variation in individuals’ attainment of fitness via sperms versus eggs (functional gender) and the diversity of gender morphs found in populations. We extend D.G. Lloyd's classification of flowering plant gender to all land plants, with three main functional classes according to whether populations are dimorphic or monomorphic for gender (i.e., populations consist of either one or two distinct sex classes), and at which life cycle stages this occurs: (1) sporophyte-dimorphic, (2) sporophyte-cosexual and gametophyte-dimorphic, and (3) gametophyte-cosexual. In dimorphic sporophytes and gametophytes, morphs that reproduce mostly as females and males may be constant (dioecy) or inconstant (gynodioecy, androdioecy, trioecy). We suggest that examining the sex conditions of seedless plants using a functional perspective will reveal a diversity of sexual systems largely analogous to those found in seed plants. An extended suite of model plants with different biological attributes will allow new tests of existing models of mechanisms that select for different sexual systems, and may lead to important new questions in the field, some of which we suggest here.

In Silico Identification and Evolutionary Analysis of Plant MAPKK6s

Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules in plants. Linking upstream MAPK kinase kinase (MAPKKK) to downstream MAPK, MAPK kinase (MAPKK) plays a crucial role in MAPK cascade. MAPKK6 is one member of the MAPKK family. In this study, we have found that plant MAPKK6 genes are widely distributed in different plant species, including moss, seedless vascular plants, gymnosperms, and angiosperms. However, no MAPKK6 can be found in genomes of algae. Analysis of exon–intron organization and intron phase showed that plant MAPKK6s are highly conserved genes during plant evolution. In Physcomitrella patens, Selaginella moellendorffii, and Picea glauca, MAPKK6s exist as multicopy genes. In most high plants, however, MAPKK6s exist as single-copy. Phylogenetic analysis indicated that the occurrence of single-copy of MAPKK6s in high plants is likely because of genomic copy-number loss.

Ethnopharmaceutically important medicinal plants and its utilization in traditional system of medicine, observation from the Northern Parts of Pakistan.

Wild medicinal plants gathering for the treatment of various human ailments is an ancient tradition that has endured in mountainous areas of Pakistan. In order to understand the pattern and uses of plants, a study on the Ethnopharmaceutically important medicinal plants of Shawar valley, District Swat was conducted during summer 2008. Information’s about these plant resources were collected through semi-structured interviews, field observation and group discussion. In order to documents the preset use of medicinal plants growing in and around the study area an elderly person up to age group 60 was mostly interviewed. The study revealed that 87 plants species of 58 families of having ethnomedicinal importance. There were 50 Dicotyledonous families, 3 Monocotyledons families (Aliaceae, Iridacea and Poaceae), 2 Gymnosperms families (Pinaceae and Taxaceae) 2 Pteridophytes families (Polypodiaceae and Pteridaceae) and family Halvelaceae of fungi. These species were used for the curing of various human ailments in indigenous system of medicines. Some plants are used singly while many others are used in combination with other plants or edible items. Similarly, few plants species are considered for the treatment of only one specific disease while several other have multiple such medicinal uses. These are mostly used for the curing of gastro-intestinal problems, emmenagogue and antispasmodic and also for general body tonic. The detail local uses, local method of recipe preparation and application along with their local name and disease treated were reported for each species. The study also observed that the availability of pharmaceutically and therapeutically important MAP species is declining and the number of rare and threatened species among the MAPs is increasing in the area. Further study is, therefore, required to quantify the availability of species and to suggest suitable method for their production and conservation. Recommendations are, therefore, given in the spheres of training in identification, sustainable collection, value addition, trade monitoring and cooperative system of marketing of medicinal plants.

The Pteridophyta and the paleoenvironment of the middle part of the La Ternera Formation (Upper Triassic) at Quebrada La Cachivarita, Atacama Region, Chile.

Se describen e ilustran diez especies de Pteridophyta procedentes de estratos de la parte media de la Formacion La Ternera (Triasico Superior), aflorantes en la quebrada La Cachivarita, afluente norte de la quebrada Paipote, Provincia de Copiapo, III Region, Chile. Se trata de Rienitsia ternerae, Todites chilensis, Todites sp., Neocalamites carrerei, Asterotheca rigbyana, Asterotheca fuchsi, Cladophlebis mendozaensis, Cladophlebis kurtzi, Gleichenites cachivaritensis y Dictyophyllum (D.) tenuifolium, de las cuales las dos primeras son nuevas. El conjunto paleofloristico confirma la edad triasica superior asignada con anterioridad a la Formacion La Ternera. El estudio sedimentologico de la seccion que incluye tales estratos permitio distinguir cinco facies diferentes que, en conjunto, son interpretadas como depositos en un lago que progresivamente se torna mas somero.

Vegetational diversity along an altitudinal range in Garhwal Himalaya

Four forest habitats varying in different vegetation were studied along an altitudinal range of 1900-2200 m called low elevation forests. These forests were close to human habitation with high disturbance. A total of 209 plant species were recorded out of which 29 were trees, 50 shrubs, 102 herbs, 11 climbers, 7 epiphytes, 4 pteridophytes, 3 bryophytes and 3 parasites. Maximum tree species were recorded on moist site (22) and minimum on ridge site (12). Maximum shrub species were present both on stream bank and dry site (31 at each site). Maximum herb and climber species were present on dry and moist site (62 and 8) respectively. Species relationship between the sites indicates that 11 trees, 20 shrubs, 41 herbs, 4 climbers, 2 pteridophytes, 1 bryophyte and 2 parasites were common in stream bank and dry site. The mean tree, shrub and herb species richness was maximum on stream bank (6.3 ± 0.2), moist (6.1 ± 0.3) and dry (10.3 ± 0.4) and minimum on ridge site (4.6 ± 0.3), (5.5 ± 0.4), (7.6 ± 0.5) respectively. Comparison similarity between the sites revealed maximum similarity among stream bank and moist sites (70%) for trees and minimum between ridge and moist site (32.43%) for herbs. The high similarity index between moist and stream bank site may be due to similar environmental conditions on both the sites. Key words: Species richness, study sites, vegetation, Garhwal Himalaya.

Resources of pteridophyte plants in Zhejiang-Dongqian lake area

Objective To make clear the resources of pteridophyte in Zhejiang-Dongqian lake area.Methods Field investigation, data reference and consultation to local peasants were adopted. Results There are 20 famines, 23 genera, and 26 species of medicinal ferns in Dongqian Lake area. Conclusion Medicinal ferns are abundant in Zhejiang-Dongqian lake area. Key words: Dongqian Lake; Medicinal ferns; Pteridophyte resources; Value

Eukaryotic Microbial Communities Associated with the Rhizosphere of the Temperate Fern Thelypteris noveboracensis (L.) Nieuwl

Abstract Microbial communities, associated with terrestrial mosses (Bryopsida) and the rhizosphere of agricultural and natural occurring seed plants, have been rather extensively examined; but less is known about associations with seedless vascular plants, including ferns. The New York fern (Thelypteris noveboracensis), typically found within deciduous forests, occurs in locally extensive stands in North America extending from northeastern Canada to southeastern U.S.A. Soil samples were obtained in autumn (2007) and early summer (2008) within a plot of T. noveboracensis in the understory of deciduous trees in the forest reserve at Torrey Cliff, NY to document the rhizosphere (root-associated) density of commonly occurring heterotrophic eukaryotic microbes (protozoa), including microflagellates, naked amoebae and testate amoebae. The ranges in densities (number/g soil dry weight) are as follows: microflagellates (6.5 × 106–1.3 × 108), naked amoebae (1.8 × 103–4.0 × 106) and testate amoebae (ca. 400). Very ...

Flora of Mehsana District, North Gujarat

The present study envisages an account of vegetation and floral composition of phytodiversity of Mehasana district, Gujarat, It comprises 487 species of angiosperms, belonging to 287 genera under 86 families and two species of pteridophytes.

Red Light Inhibition of Spore Germination in Lycopodium clavatum

Most studies of spore germination in seedless vascular plants have involved species that develop surficial, photosynthetic gametophytes following spore germination. However, several species, including Lycopodium clavatum, give rise to subterranean, nonphotosynthetic, mycorrhizal gametophytes and their spores germinate in the dark. Red light, like white light, inhibits the germination of these spores. Germination occurs after exposure to far-red light. The effects of far-red light are reversed by red light and those of red light are reversed by far-red light confirming the involvement of phytochrome. The active form of phytochrome, Pfr, inhibits germination in L. clavatum. It appears that this is a general phenomenon in seedless vascular plants with subterranean, mycorrhizal gametophytes because it is now known to occur in two species, L. clavatum and Ophioglossum crotalophoroides, from unrelated families. The photoinhibition of germination by white or red light insures that these spores germinate underground in nature providing improved chances of spores obtaining adequate soil moisture and mycorrhizal colonization of young gametophytes that are essential for continued development.

Moss and liverwort xyloglucans contain galacturonic acid and are structurally distinct from the xyloglucans synthesized by hornworts and vascular plants*

Xyloglucan is a well-characterized hemicellulosic polysaccharide that is present in the cell walls of all seed-bearing plants. The cell walls of avascular and seedless vascular plants are also believed to contain xyloglucan. However, these xyloglucans have not been structurally characterized. This lack of information is an impediment to understanding changes in xyloglucan structure that occurred during land plant evolution. In this study, xyloglucans were isolated from the walls of avascular (liverworts, mosses, and hornworts) and seedless vascular plants (club and spike mosses and ferns and fern allies). Each xyloglucan was fragmented with a xyloglucan-specific endo-glucanase and the resulting oligosaccharides then structurally characterized using NMR spectroscopy, MALDI-TOF and electrospray mass spectrometry, and glycosyl-linkage and glycosyl residue composition analyses. Our data show that xyloglucan is present in the cell walls of all major divisions of land plants and that these xyloglucans have several common structural motifs. However, these polysaccharides are not identical because specific plant groups synthesize xyloglucans with unique structural motifs. For example, the moss Physcomitrella patens and the liverwort Marchantia polymorpha synthesize XXGGG- and XXGG-type xyloglucans, respectively, with sidechains that contain a beta-D-galactosyluronic acid and a branched xylosyl residue. By contrast, hornworts synthesize XXXG-type xyloglucans that are structurally homologous to the xyloglucans synthesized by many seed-bearing and seedless vascular plants. Our results increase our understanding of the evolution, diversity, and function of structural motifs in land-plant xyloglucans and provide support to the proposal that hornworts are sisters to the vascular plants.

Arbuscular Mycorrhizas and Dark Septate Fungi in Lycopodium paniculatum (Lycopodiaceae) and Equisetum bogotense (Equisetaceae) in a Valdivian Temperate Forest of Patagonia, Argentina

ABSTRACT Arbuscular mycorrhizas (AM) are one of the most widespread and common type of symbiotic associations. Lycopodium paniculatum and Equisetum bogotense are two important species of seedless vascular plants in a Valdivian temperate forest of Patagonia, Argentina. The mycorrhizal status of these species is completely unknown, as it is for most lycophytes and monilophytes in Argentina, where information on symbiotic interactions in these plants is scarce. In this study, typical AM structures were observed in sporophytes of L. paniculatum and E. bogotense. The percentage of root length colonized by AM fungi ranged from 0 to 50% in the first species and from 0 to 22.5% in E. bogotense. Both species were facultative mycorrhizal and it was observed that the habitat and substrate seem to play an important role in determining the colonization intensity. The morphological AM colonization pattern was considered an Intermediate-type. Dark septate fungi, characterized by septate hyphae and microsclerotia, were a...

Development issues in extending plant-based IBIs to forested wetlands in the Midwestern United States

Most plant-based indices of biotic integrity (IBIs) developed for wetlands have focused on emergent wetlands. A Vegetation Index of Biotic Integrity (VIBI-Forest) was developed for forested wetlands in the four large ecoregions of the Ohio. Assessing the effect of human disturbance on the ecological condition of wetland forests is complicated by several factors. First, forest canopies can remain largely intact even after significant degradation of the herb and shrub stratum. Second, increases in total diversity may not be good. In forested wetlands, a major artifact of disturbance is the addition of non-wetland or wetland native or adventive plant species adapted to full sun conditions to their floras. Initial versions of the VIBI-Forest metrics were very sensitive to disturbance-induced increases in diversity. Correcting this problem required modifying or replacing metrics so that only forest dependent species were included in metric calculations. The final VIBI-Forest included metrics which evaluated each forest stratum including the ground layer (% bryophyte), herb layer (shade or seed-less vascular plant species), shrub layer (subcanopy importance value (IV), relative density of young trees), canopy (canopy IV), and composite metrics for all vertical strata (Floristic Quality Assessment Index score, % hydrophytes, % sensitive, % tolerant). Assessing wetland forest condition is further complicated by the fact that some successional communities after canopy death or destruction (shrub swamp, marsh, wet meadow) may have intrinsic value as wetland community types. The solution is not to attempt to derive a one-size-fits-all assessment method but to derive separate protocols for other successional phases that are of value or interest.

Some Traditional Herbal formulations in the Treatment of Rheumatism from Jalgaon District, Maharashtra

Information on 91 plant species used especially for the treatment of rheumatism, arthritis and general with such complaints by rural and tribal communities of Jalgaon district, Maharashtra is presented in this paper. The paper reveals utilization of 90 species of flowering plants belonging to 83 genera of 47 families. Besides, one fern is recorded for ethnobotanical purpose. Of these, 42 families are of dicotyledoneae class while 4 belong to monocotyledoneae and 1 to pteridophytes. Brief information about the plant / plant parts used, botanical names, local names, distribution, families and the mode of preparation of drugs have been presented. As the traditional herbal remedies are based on ancestral knowledge and empiric experiences, this type of ethno-medicinal survey appeared to be useful for the research on medicinal plants for the betterment of mankind.

Levantamento florístico das Pteridófitas (Lycophyta e

Thi s wor k pre sent s a flori sti c survey o f the pterido phyte s (Lycophyta e Monilo phyta ) o f the Parque Ambiental of Belem in the Municipality of Belem, State of Para. This Park is part of the a Environmental Protected Area, representing one of the last relatively conserved forest remnants in Belem metropolitan area. Through collections realized from October 2002 to January 2004, 18 families, 30 genera and 49 species were recorded. The families with the largest number of species were Polypodiaceae and Hymeno phylla ceae , both with six specie s, folo wed by the Pterida ceae , with fi ve specie s. The mostre - presentative genera were Trichomanes L., with fi ve specie s, folo wed by Cyathea Sm., Microgramma C. Presl, Thelypteris Schmidel, Nephrolepis Schott and Lindsaea Dryand, with three species each. Of the 49 species recorded for the area, two are new references for the State of Para, Danaea trifoliata Kunze and Lindsaea divaricata Klotzsch, and two, for the North Region of Brazil: Cyclodium heterodon (Schrad.) T. Moore var. abbreviatum (Presl) A.R. Sm. and Thelypteris chrysodioides (Fee) C.V. Morton.

The Pteridophytes of Mexico

The Pteridophytes of Mexico

Unresolved problems on the origin and early evolution of land plants.

The origin of land plants or embryophytes from the Charophyceae is generally accepted today by the botanists. In fact, numerous morphological, cytological, ultrastructural, biochemical and molecular characters are shared in these organisms. A fundamental problem is still constituted by the evolution of the sporophyte, i.e. the appearance of two different phase cycles (gametophyte/sporophyte alternance), although two theories ("antithetic" and "homologous") try to explain this evolutionary event.However, another phylogenetic dilemma is represented, in my opinion, either by the formation of bryophytes or by the transition from these first land plants to the pteridophytes, considering them at whole organism level. The bryophyte gametophyte is the most elaborate of the land plants. It presents several complex characters, principally the growth developmental form, the appearance of multicellular sex organs, antheridia and archegonia. Also the sporophyte shows a complicated structure that is not found in the other land plants or tracheophytes. The sporangium, in particular, exhibits some intricate morphological traits such as the peristome of true mosses for spore dispersion, the elaters of liverworts and the indeterminate growth in the hornworts. The pteridophytes are represented especially by their dominant sporophyte. This latter has the capacity to produce multiple sporangia and, in many cases, two kinds of spores which develop in male and female gametophyte (heterosporous pteridophytes). Another important characteristic of this sporophyte is its ability to become independent of the gametophyte. However, one of the most innovative character is the formation of true vascular elements (xylem and phloem). All these very large evolutionary jumps are discussed on the basis of the phyletic gradualistic neo-Darwinian theory and the punctuated equilibrium theory of Eldredge and Gould. In this context other genetic evolutionary mechanisms are also considered.Nevertheless, the origin of bryophytes and pteridophytes remain, at the moment, a mystery.

Cytotaxonomic studies of the Chinese pteridophytes: A review

Cytotaxonomic studies of the Chinese pteridophytes: A review

(1746) Proposal to conserve the name Marattiaceae against Danaeaceae (Pteridophyta)

TAXONVolume 55, Issue 4 p. 1040-1042 Proposals to Conserve or RejectsFree Access (1746) Proposal to conserve the name Marattiaceae against Danaeaceae (Pteridophyta) Andrew G. Murdock, murdock@berkeley.edu Department of Integrative Biology, University of California, Berkeley, California, 94720-2465 U.S.A.Search for more papers by this authorJames L. Reveal, jreveal@umd.edu Professor Emeritus, University of Maryland, College Park, Maryland, 20742-5815 U.S.A. Honorary Curator, New York Botanical Garden, Bronx, New York, 10458-5126Search for more papers by this authorAlexander Doweld, nicar-sekretariat@yandex.ru National Institute of Carpology (Gaertnerian Institution), PO Box 72, RUS-11917 Moscow, Russian FederationSearch for more papers by this author Andrew G. Murdock, murdock@berkeley.edu Department of Integrative Biology, University of California, Berkeley, California, 94720-2465 U.S.A.Search for more papers by this authorJames L. Reveal, jreveal@umd.edu Professor Emeritus, University of Maryland, College Park, Maryland, 20742-5815 U.S.A. Honorary Curator, New York Botanical Garden, Bronx, New York, 10458-5126Search for more papers by this authorAlexander Doweld, nicar-sekretariat@yandex.ru National Institute of Carpology (Gaertnerian Institution), PO Box 72, RUS-11917 Moscow, Russian FederationSearch for more papers by this author First published: 01 November 2006 https://doi.org/10.2307/25065710Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume55, Issue4November 2006Pages 1040-1042 RelatedInformation