1000 resultados para Botânica - Embriologia


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En el presente trabajo estudiamos la flora liquenológica del Barranco de Linares (provincia de Huelva). Han sido recolectadas 79 especies, de las cuales probablemente Thelidium pyrenophorum (Ach.) Mudd, lecidea vorticosa (Floerke) Koerb. y Buellia disciformis (Fr.) Mudd, sean indicadas por primera vez para España. Varias de las citas son nuevas para Andalucía Occidental.

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irregular. With reference to the 10 km UTM network, the number of relevés per cell ranges between 0 and 527, with a mean of 36, the most exhaustively prospected areas lying in the Pyrenean range. On the other hand, 44 cells spread ± regularly over the Catalan territory have not available relevés yet, the larger spot lying in the Lluçanés area (C Catalonia). As a general rule. communities seem to be rather adequately prospected and no great discordances between syntaxa have been observed. However. further studies may be required for several alliances such as Berberidion, Pruno-Rubion ulmifolii, Taeniathero-Aegilopion, Alkanno-Malcolmion, Thero-Suaedion, Posidonion or Rupion maritimae. Key words: Phytocoenology, Relevés Database, Geographical prospection, Syntaxonomical prospection, Catalonia.

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Data about 89 taxa are presented. Arabis nova Vill. subsp. iberica Rivas Mart. ex Talavera, Cistus × nigricans Pourr. and Phacelia tanacetifolia Benth. are new records for the Catalan flora, and 15 taxa (Allium oporinanthum Brullo et al., Apera interrupta (L.) Beauv., Asplenium trichomanes L. subsp. trichomanes, Campanula affinis Schult., Carex sylvatica Huds. subsp. paui (Sennen) A. and O. Bolòs, Epilobium angustifolium L., Limonium hibericum Erben, Melilotus messanensis (L.) All., Minuartia funkii (Jord.) Graebner, Onosma triceros-perma subsp. catalaunica (Sennen) O. Bolòs and Vigo, Orchis palustris Jacq., Orchis simia Lam., Selaginella denticulata (L.) Spring, Stellaria neglecta Weihle in Bluff and Fingerh. and Vaccinium myrtillus L. are new records for Southern Catalonia.

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Biosystemalic study of the Ferula communis populations in NE of the Iberian Peninsula and in the Balearic Islands. this paper presents the results of a taxonomic revision of the collective species Ferula communis L. (Umbelliferae) in NE of the Iberian Peninsula and Balearic Islands. The main goal of the research has been to characterize the Ferula communis populations in the region under study and to place them into infraspecific taxa. The proposed classification is based on morphology, anatomy, phenology, karyology and numerical taxonomy. A new taxon is described: Ferula communis L. subsp. cardonae Sanchez-Cuxart and Bernal and two new nomenclatural combinations are proposed: Ferula communis L. subsp. catalaunica (Pau) Sanchez- Cuxart and Bernal and Ferula communis L. subsp. catalaunica var. microcarpa (Cauwet-Marc) Sanchez-Cuxart and Bernal. Description, phenology and chorology for each taxon are included. Also an identification key for infraspecific taxa and a list of new localities are provided.

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Catalogue of endemic, rare or threatened vascular plants in Catalonia. I. Endemic taxa. This is the first of a set of papers devoted to rare or threatened plants in Catalonia. We list 279 specific or subspecific taxa which are in a broad sense endemic to the northeastern part of the Iberian Peninsula. We assess them with regard to their conservation status according to IUCN criteria. Assignment of these taxa to established categories has led to the following results: 6 taxa critically endangered (CR), 5 endangered (EN), 32 vulnerable (VU), 5 near threatened (LR nt). 84 least concern (LR lc), 116 not threatened (NT) and 31 data deficient (DD). The small number of taxa that enjoy legal protection in comparison with the number of threatened plants is emphasized. Key words: Endemic plants, Catalonia, Plant conservation, UICN categories.

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The first part of a general survey of the vegetation of Catalonia andAndorra, this paper reports all the phytocoenological associations and subassociations recorded in this area. For each community, we provide the correct name and usual synonyms, its typification (where appropriate), all the references including relevés, and the most outstanding features of its structure, species composition, ecology, distribution and diversity. Moreover, associations and subassociations are ordered appropriately in a syntaxonomic scheme. Syntaxonomic ranks are considered in a fairly broad, conservative sense. This classification established 101 associations, which correspond to the classes Lemnetea, Zosteretea, Potametea, Littorelletea, Montio-Cardaminetea, Phragmiti-Magnocaricetea, Scheuchzerio-Caricetea, Isoeto-Nanojuncetea and Molinio-Arrhenatheretea.

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Data banks on the flora of the Catalan Countries. Two data banks on the flora of the Catalan Countries (NE and E of the Iberian Peninsule and Balearic Islands) have been set up by the Secció de Ciències of the Institut d'Estudis Catalans (I.E.C., Institute of Catalan Studies). One is devoted to bibliography and the other to floristics, in this first phase concerned only with vascular plants. The sources are all types of publications containing concrete information on the vascular flora of the Catalan Countries. The information is transcribed on precoded forms so as to standardize the data and thus permit homogeneous input for subsequent storage in the computer. The coding schemes and characteristics of the forms are described for each of the data banks. Only the phytocoenological inventories receive special treatment which is discussed withreference to the floristic data bank. A first issue is annexed: the bibliografy concerning the vascular flora of Catalan Countries (years 1983 and 1984).

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Background Plant hormones play a pivotal role in several physiological processes during a plant's life cycle, from germination to senescence, and the determination of endogenous concentrations of hormones is essential to elucidate the role of a particular hormone in any physiological process. Availability of a sensitive and rapid method to quantify multiple classes of hormones simultaneously will greatly facilitate the investigation of signaling networks in controlling specific developmental pathways and physiological responses. Due to the presence of hormones at very low concentrations in plant tissues (10-9 M to 10-6 M) and their different chemistries, the development of a high-throughput and comprehensive method for the determination of hormones is challenging. Results The present work reports a rapid, specific and sensitive method using ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UPLC/ESI-MS/MS) to analyze quantitatively the major hormones found in plant tissues within six minutes, including auxins, cytokinins, gibberellins, abscisic acid, 1-amino-cyclopropane-1-carboxyic acid (the ethylene precursor), jasmonic acid and salicylic acid. Sample preparation, extraction procedures and UPLC-MS/MS conditions were optimized for the determination of all plant hormones and are summarized in a schematic extraction diagram for the analysis of small amounts of plant material without time-consuming additional steps such as purification, sample drying or re-suspension. Conclusions This new method is applicable to the analysis of dynamic changes in endogenous concentrations of hormones to study plant developmental processes or plant responses to biotic and abiotic stresses in complex tissues. An example is shown in which a hormone profiling is obtained from leaves of plants exposed to salt stress in the aromatic plant, Rosmarinus officinalis.

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Nos referiremos en primer lugar a D. multiaffinis Pau (Bol. Soc. Esp. Hist. Nat. 21:142. 1921). Descrito de la Sierra de Espadan, pocos han sido los autores posteriores que han tenido en cuenta este nombre. Únicamente, O. DE BOLÓS& J. VIGO (Butll. Inst. Catalana Hist. Nat. 38: 88.1974) lo subordinan como variedad a D. pungens L. dentro de la subespecie multiceps (Costa ex Willk.) Bolos & Vigo y, más recientemente, M. Laínz propone la...

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En el presente trabajo exponemos los resultados del estudio cariológico de ocho táxones del género Dianthus L. Los recuentos se han llevado a cabo en mitosis somáticas de ovario, procedentes de botones florales fijados en el campo. La fijación se realizó con alcohol absoluto/ácido acético ferrocarminado, en proporción 4:1, conservándose posteriormente el material, hasta el momento de su estudio, a -18 °C. Las preparaciones se obtuvieron mediante el método de aplastamiento previa tinción con carmín acético, utilizando acetato férrico como mordiente. Los pliegos testigo están depositados en el herbario BCC (Facultad de Biología de la Universidad de Barcelona).

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A new subspecies of Pedicularis pyrenaica J. Gay (Scrophulariaceae) in Central Pyrenees. We describe a new subspecies of Pedicularis pyrenaica (P. pyrenaica subsp. praetermissa) from the Central Pyrenees, which differs from the typical in the shape of the upper lip of the corolla (fusiform, attenuated in a conical beak), as for the larger size of the corolla and the whole plant. We add several comments on the morphological characterization and the habitat of the plant in relation to close taxa

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Presentamos en esta primera nota un análisis de la especie Hygrocybe conicoides (Orton) Orton y Watling, primera cita para el catalogo micológico de Cataluña. Se tratan los aspectos macroscópicos y microscópicos, así como los caracteres diferenciales de la especie y su identidad taxonómica. Hygrocybe conicoides aparece como un hongo psamófilo, posiblemente citado en otras ocasiones como forma arenícola de H. nigrescens e H. cónica (LOSA QUINTANA, 1968; HEIM, 1934).

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Se da cuenta del hallazgo, en el SE de España de 28 especies, pertenecientes a: Uredinales (15, entre las cuales: Gymnosporangium confusum Plow., G. fuscum D. C., G. gracile P a t., Puccinia atropae Mont., P. barbeyi (Roum.) Magn., P. tumida Grev., Uromyces monspessulanus Tranzsch.), Ustilaginales (4), Tremelales (4, con Exidiopsis grisea (Pers.) Bdot. y Maire, E laccata (Bdot. y Galz.) Luck-Allen), Auriculariales (1), Septobasidiales (Septobasidium mariani Bres.) y Dacrimicetales (3, con Calocera palmata (Schum.) F r.).

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A queima da vegetação se reflete sobre o solo, a composição botânica, o desenvolvimento das espécies, e também sobre a qualidade da forragem. O objetivo deste trabalho foi estudar cinco sistemas de manejo da pastagem nativa, em relação às queimadas. Foram avaliados os seguintes sistemas, todos pastejados: com queima bienal há mais de 100 anos; sem queima há 32 anos com ou sem roçada; e melhorado há 7 e 24 anos. O delineamento experimental foi o completamente casualizado com três repetições. Os teores de proteína bruta e de digestibilidade in vitro da matéria orgânica foram maiores nas áreas sob melhoramento e roçada. O teor de N não diferiu entre tratamentos, enquanto os teores de P, K, Ca e Mg foram maiores na forragem da área melhorada, e não diferiram nos demais tratamentos. A quantidade acumulada de nutrientes nos tecidos, reflexo da produção de forragem, foi maior nos sistemas sem queima.