Guía para una excursión botánica en las Sierras de Córdoba

Se presenta una guía para una excursión botánica a través de las Sierras Grandes, llanos y valles del oeste de Córdoba. Se visitan diferentes pisos de vegetación del Distrito Chaqueño Serrano y parte de los bosques xerófilos de llanura del Distrito Chaqueño Occidental. La guía presenta descripciones de los bosques, matorrales y pastizales serranos de las laderas oriental y occidental de las Sierras Grandes, de los palmares de la Pampa de Pocho y parches de bosques de Aspidosperma quebracho-blanco en los valles y llanos en contacto con las sierras.Botanical excursion through the Córdoba Mountains. A botanical guide through the Sierras Grandes, lowlands and valleys from western Córdoba is presented. The Mountain Chaco and the Western Chaco Districts are visited. The guide includes the description of mountain woodlands, shrublands and grasslands occurring in both the eastern and western slopes of the Sierras Grandes and the Pampa de Pocho, as well as Aspidosperma quebracho-blanco forests patches present in lowlands and valleys close to the mountains.Fil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Giorgis, Melisa Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Tourn, Monica. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica Agrícola. Laboratorio Estación de Biología Sierras; Argentin

Guía para una excursión botánica en las sierras de Córdoba Botanical excursion through the Córdoba Mountains

Se presenta una guía para una excursión botánica a través de las Sierras Grandes, llanos y valles del oeste de Córdoba. Se visitan diferentes pisos de vegetación del Distrito Chaqueño Serrano y parte de los bosques xerófilos de llanura del Distrito Chaqueño Occidental. La guía presenta descripciones de los bosques, matorrales y pastizales serranos de las laderas oriental y occidental de las Sierras Grandes, de los palmares de la Pampa de Pocho y parches de bosques de Aspidosperma quebracho-blanco en los valles y llanos en contacto con las sierras.A botanical guide through the Sierras Grandes, lowlands and valleys from western Córdoba is presented. The Mountain Chaco and the Western Chaco Districts are visited. The guide includes the description of mountain woodlands, shrublands and grasslands occurring in both the eastern and western slopes of the Sierras Grandes and the Pampa de Pocho, as well as Aspidosperma quebracho-blanco forests patches present in lowlands and valleys close to the mountains

Una aproximación a la arquitectura vegetal: conceptos, objetivos y metodologia

International audienceA synthesis of concepts, definitions and methods used in plant architectural studies is provided with a brief review of the field's terminology and a comparison with the usual morphological terms. The concept of architecture (Hallé & Oldeman, 1970) involves the idea of plant form and its history. The concept of the architectural model and reiteration, applies to the development of plant form along the life cycle. The tools and plant morphological traits used in architectural studies are dealt with and the applications of plant architecture to other botanical fields are discussed

Una aproximación a la arquitectura vegetal: conceptos, objetivos y metodologia

International audienceA synthesis of concepts, definitions and methods used in plant architectural studies is provided with a brief review of the field's terminology and a comparison with the usual morphological terms. The concept of architecture (Hallé & Oldeman, 1970) involves the idea of plant form and its history. The concept of the architectural model and reiteration, applies to the development of plant form along the life cycle. The tools and plant morphological traits used in architectural studies are dealt with and the applications of plant architecture to other botanical fields are discussed

Effect of ultraviolet-B radiation on salt marsh vegetation: trends of the genus salicornia along the Americas

The effects of natural UV-B radiation on growth, photosynthetic and photoprotective pigment composition of different Salicornia species were analyzed in salt marshes at three different sites along the Americas (Puerto Rico, southern Brazil and Patagonia, Argentina). Plants were exposed to different levels of UV-B radiation for 1–2 years in situ as well as in outdoor garden UV-B exclusion experiments. Different UV-B levels were obtained by covering plants with UV-B opaque (blocked 93–100% of ambient UV-B) and UV-B attenuating (near-ambient) filters (reduced 20–25% of UV-B). Unfiltered plants were exposed to natural irradiance. UV-B filters had significant effects on temperature and photosynthetic pigments (due to changes in PAR; 400–700 nm). The growth of Salicornia species was inhibited after 35 to 88 days of exposure to mean UV-B radiation dosages between 3.6 and 4.1 kJ m22 day21. The highest number of branches on the main shoot (S. bigelovii and S. gaudichaudiana) and longest total length of the branches (S. gaudichaudiana) were observed in the UV-B opaque treatment. Salicornia species responded to increasing levels of UV-B radiation by increasing the amount of UV-B absorbing pigments up to 330%. Chromatographic analyses of seedlings and adult S. bigelovii plants found seven different UV-B absorbing flavonoids that are likely to serve as UV-B filtering pigments. No evidence of differential sensitivity or resilience to UV-B radiation was found between Salicornia species from low-mid latitudes and a previously published study of a high-latitude population

Distribution of (-)-hamanasic acid A in South American species of Flourensia and phytotoxic effects of leaf aqueous extracts.

The presence of the phytotoxic sesquiterpene (-)-hamanasic acid A {(-)HAA; 7-carboxy-8-hydroxy-1(2), 12(13)-dien-bisabolene} isolated from Flourensia campestris (FC), was investigated in the South American species of the genus, together with the evaluation of the phytotoxic activity of their leaf aqueous extracts. (-)HAA was identified and isolated from F. fiebrigii (FF) and F. oolepis (FO), being chemically (GC-MS, NMR, [α]D) and biologically (bioassayed on lettuce) indistinguishable from that of FC, while no (-)HAA was found in F. hirta (FH), F. riparia (FR) and F. niederleinii (FN). Its leaf content in FF was similar to that found in FC (ca. 15 mg g-1 WT) and significantly higher than in FO (0.8 mg g-1 WT). The screening for the presence of (-)HAA in other species of Flourensia communities showed that its natural occurrence is restricted only to Flourensia species. No (-)HAA could be detected in any of the 37 -most representative- species of these communities (26 natives, 11 exotics), despite many of them belong to the same family and tribe as Flourensia spp. Leaf aqueous extracts of all Flourensia species exhibited strong inhibitory effects on lettuce germination and on root and shoot growth, regardless of the presence and content of (-)HAA. These results strongly suggest the existence of other powerful phytotoxic compounds in those Flourensia spp lacking (-)HAA. Our results clearly show that (-)HAA only pertains to some species of the genus Flourensia. Relative to previous exomorphologic groupings of the genus, our chemotaxonomic data would give support to the close link described between FC and FF, but not with FR. In addition, the fact that (-)HAA was also found in FO, which belongs to a second different line, also points out that species position in this lineage would deserve to be revisited. The restricted production of (-)HAA by Flourensia in their communities suggests its special link with the genus, and sustains its putative allelochemical role.Fil: López, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Silva, Mariana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Piazza, Leonardo A. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Silva, Mariana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Lopez Rivilli, Marisa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Cantero, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Tourn, Graciela Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Scopel, Ana Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Secretory Structures in Flourensia campestris and F. oolepis: Ultrastructure, Distribution, and (-)-Hamanasic Acid A Secretion

In this work, the localization, density, morphology and ultrastructure of secretory structures in aerial organs of Flourensia campestris (FC) and F. oolepis (FO) (Asteraceae) by means of a combination of light, fluorescence, transmission (TEM) and scanning electron microscopy (SEM) were examined. The possible role of secretory structures in the production and secretion of the phytotoxic sesquiterpene (-)-hamanasic acid A ((-)HAA) in both species was also assessed. Capitate glandular trichomes were found in all reproductive organs of FC and FO, and were being reported for the first time. These glandular trichomes, typically associated to edges and veins, were of the same type as those already described for vegetative organs, and were abundant in involucral bracts and corolla of tubulose and ligulate flowers. Their density in reproductive organs of both species was similar (ca. 30/mm2) and lower than that found in leaves (ca. 100/mm2) and stems (ca. 160/mm2 in FC, and up to 650/mm2 in FO). Glandular trichomes in vegetative organs followed a species- specific pattern of distribution. TEM and SEM observations suggest that each species differs in the way in which secretory materials are released to the outside: through cracks or pores in FC, or through a loose cuticle in FO. Similar inspections of the secretory ducts revealed lipophilic vacuoles localized in subepithelial and epithelial cells, in which secretions accumulated before being transferred to the duct. The presence of wall ingrowths in subepithelial cells suggests that granulocrine secretion operates in these species. Secretory ducts varied in density and diameter among the organs in both species, with the combination being maximal in woody stems. (-)HAA was only detected in surface secreted resins of both species, and its concentration (2D-TLC, GC-FID) was intimately associated with the distribution and density of glandular trichomes in each organ (capitula, leaves, and stems with primary or secondary growth). In addition, no (-)HAA was detected internally in the resins collected from secretory ducts. The composition of these resins showed distinctive profiles for FC and FO, and only four from ca. 30 compounds detected (GC/MS) were shared by both species. In addition to the elucidation of ultrastructural traits, distribution and density of secretory structures in aerial organs of FC and FO, present findings suggest a functional role for glandular trichomes in the secretion of the putative phytotoxic allelochemical (-)HAA.Fil: Silva, Mariana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Tourn, Graciela Monica. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; ArgentinaFil: López, Daniela Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piazza, Leonardo A. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Zarlavsky, Gabriela Elena. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; ArgentinaFil: Cantero, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Biología Agrícola; ArgentinaFil: Scopel, Ana Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; Argentin

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