Caracterización ecológica de Astragalus gines-lopezii, un endemismo extremeño En Peligro (EN, LR2008)

Astragalus gines-lopezii Talavera et al. es un endemismo de la provincia de Badajoz que cuenta con menos de 1000 ejemplares en 2 poblaciones: la más importante está en la Sª de Mª Andrés, en un matorral dominado por Cistus albidus, con Genista hirsuta, Cistus monspeliensis, Teucrium gr. polium, Retama sphaerocarpa, Quercus coccifera, etc. y pies dispersos de encina (Quercus ilex ssp. ballota) y acebuches (Olea europaea var. sylvestris). La población de la Sª Calera, se encuentra en medios más antropizados: en un olivar y como ruderal. Los sustratos presentan pH en agua claramente básicos (entre 7,9 y 8,37) y en KCl oscila entre 7,3 y 7,6; ligados a unos contenidos significativos de carbonatos procedentes de rocas calizas compactas cuasi marmóreas. También destacan los contenidos de materia orgánica (entre 1,33 % y 3,56 %,) así como unos valores de nitrógeno total entre 0,31% y 0,15%. Se trata por tanto de suelos con altas tasas de descomposición de la materia orgánica (C/N ¿ 8). Desde el punto de vista físico presentan significativos contenidos de elementos gruesos (% elementos mayor que 2 mm ¿ 48 ) y con texturas en las que tiende a predominar la fracción limosa (% limo ¿ 50) Clima. La precipitación total anual oscila entre 754 y 650 mm y la temperatura media anual entre 16,2 y 15,3 ºC. Las medias de las máximas del mes más cálido 33,9 y las mínimas del mes más frío 3,48 º

Is it appropriate protective figure "Plant Micro-Reserves" to protect tree species? The example of Betula pendula subsp. fontqueri in "La Garganta de los Caballeros" (Ávila)

The figure of protection "micro-reserves" was created in the Region of Valencia (ANONYMOUS, 1994) with the aim of protecting endangered plant species. This is one of the areas of greatest floristic richness and uniqueness of the western Mediterranean. In this area rare, endemic or threatened vascular flora has a peculiar distribution: they appear to form small fragments spread over the entire region (LAGUNA, 1994; LAGUNA, 2001) The protection of every these small populations of great scientific value has significant challenges. It doesn´t try to protect every species that set out in Annex IV of the by then existing Law 4 / 1989 (repealed in 2007), or to protect to the most ecological level with the creation of Natural Protected Area but an intermediate level: the plant community of small size. According to the decree: “as Micro-Reserve will be declared the natural parcels of land under 20 hectares that contain a high concentration of rare plants, endemic, threatened or of high scientific interest” (ANONYMOUS, 1994) . Of course, the statement of an area as micro-reserve carries certain prohibitions that are harmful to the vegetal communit

Biología reproductiva de Astragalus gines-lopezii Talavera et al.

Astragalus gines-lopezii Talavera et al. se encuentra incluido en la Lista Roja 2008 en la categoría En Peligro (EN). Es un endemismo de área de distribución muy reducida, que tan solo cuenta con 2 poblaciones y un escaso número de ejemplares (menos que 1000). Con el objetivo de detectar posibles amenazas, hemos estudiado diferentes aspectos de su biología reproductiva: 1.- Capacidad de producir semillas viables. De 50 individuos hemos contamos, in situ, el nº de inflorescencias y el nº de flores de cada una. Posteriormente colectamos las legumbres maduras y contamos, medimos y pesamos sus semillas. En laboratorio realizamos ensayos de germinación 2.- Análisis de la capacidad germinativa de la especie en su conjunto y de cada una de sus poblaciones Las semillas se incubaron a las Tas alternas 25/15ºC, fotoperiodo de 16 h/luz y 8/oscuridad. Unas, sin ningún tratamiento previo, alcanzaron porcentajes de germinación entre 0 % y 60 %, según los diferentes individuos; sin embargo, las escarificadas alcanzaron porcentajes finales entre 60 y 100 %. En conclusión, se puede afirmar que las semillas de Astragalus gines-lopezii presentan dormición física debida a su cubierta dura e impermeable al agua. En condiciones naturales, el progresivo desgaste de la cubierta seminal por diversos factores (erosión, microorganismos, variación de temperaturas, etc.) permiten la germinación de las semillas de esta especie de forma gradual

Census, reproductive biology, and germination of Astragalus gines-lopezii (Fabaceae),a narrow and endangered endemic species of SW Spain.

Astragalus gines-lopezii Talavera, Podlech, Devesa & F.M.Vazquez (Fabaceae) is a threatened endemic species with a distribution restricted to a very small area in Badajoz Province (Extremadura Region, SW Spain) and only 2 populations are known.This species was catalogued in the "Endangered" category in the 2008 Red List and the 2010 Threatened Spanish Vascular Flora List. Despite its status as an endangered species, at present very little is known about the distribution, census, and reproductive biology of this species. In this study we have carried out anexhaustive census of A. gines-lopezii, and we have evaluated the production of flowers, fruits, and seeds and the existence or not of intra- and interpopulation variability in seed germination. Results have highlighted the high reproductive capacity of this species on the basis of a high production of flowers, fruits, and seeds. Mechanical scarification of seeds was effective for increasing germination. Thus, initial germination (22%-60%) was increased to 97%-99% when seeds were rubbed with sandpapers. A high intra- and interpopulation variability in seed germination was found in this species. A. gines-lopezii produces seeds with different degrees of physical dormancy, varying this grade among different individuals within a population

Evaluation of reproductive success in Senecio coincyi Rouy, a threatened species from Spain

Senecio coincyi Rouy (Asteraceae) is a threatened endemic species from the mountains of Sierra de Gredos, centraf western Spain. This species is protected by the Autonomous Community of Castile and León (Spain) and is included in the "In danger of extinction" category in the protected flora catalogue of that region. It was later catalogued as Vulnerable (VU) on the Red List of Threatened Spanish Vascular Flora (Moreno et al., 2008). In this paper, the results of a two-year investigation of S. coincyi population biology are shown. The aim of this work was to study several aspects of S. coincyi reproductive biology

Seed production and germination of the endangered species Astragalus gines-lopezii

Astragalus gines-lopeziiTalavera era/. {Fabaceae} is an endemic species from southwest Spain with a very limited area of distribution. There are only two known populations of this species, totaling less than 1000 individuals. This species was included on the Red List of Threatened Spanish Vascular Flora in 2008 in the category Endangered (EN) (Moreno 2008). The restricted area of distribution, limited number of individuals and their population structure could represent a high risk for survival of this species. Therefore, in order to detect potential threats, we have studied some key aspects of its reproductive biology. Fructification success and seed production were evaluated, and morphological and physiological seed variability were also studied

Automatic segmentation of rivers as a tool for assessing river responses. Case study: the Porma and Curueño rivers, nw Spain.

Automatic segmentation using univariate and multivariate techniques provides more objective and efficient segmentations of the river systems (Alber & Piégay, 2011) and can be complementary to the expert criteria traditionally used (Brenden et al., 2008) INTEREST: A powerful tool to objectively segment the continuity of rivers, which is required for diagnosing problems associated to human impacts OBJECTIVE: To evaluate the potentiality of univariate and multivariate methods in the assessment of river adjustments produced by flow regulatio

Hydrogel co-networks of gelatine methacrylate and poly(ethylene glycol) diacrylate sustain 3D functional in vitro models of intestinal mucosa

Mounting evidence supports the importance of the intestinal epithelial barrier and its permeability both in physiological and pathological conditions. Conventional in vitro models to evaluate intestinal permeability rely on the formation of tightly packed epithelial monolayers grown on hard substrates. These two-dimensional (2D) models lack the cellular and mechanical components of the non-epithelial compartment of the intestinal barrier, the stroma, which are key contributors to the barrier permeability in vivo. Thus, advanced in vitro models approaching the in vivo tissue composition are fundamental to improve precision in drug absorption predictions, to provide a better understanding of the intestinal biology, and to faithfully represent related diseases. Here, we generate photo-crosslinked gelatine methacrylate (GelMA) - poly(ethylene glycol) diacrylate (PEGDA) hydrogel co-networks that provide the required mechanical and biochemical features to mimic both the epithelial and stromal compartments of the intestinal mucosa, i.e., they are soft, cell adhesive and cell-loading friendly, and suitable for long-term culturing. We show that fibroblasts can be embedded in the GelMA-PEGDA hydrogels while epithelial cells can grow on top to form a mature epithelial monolayer that exhibits barrier properties which closely mimic those of the intestinal barrier in vivo, as shown by the physiologically relevant transepithelial electrical resistance (TEER) and permeability values. The presence of fibroblasts in the artificial stroma compartment accelerates the formation of the epithelial monolayer and boosts the recovery of the epithelial integrity upon temporary barrier disruption, demonstrating that our system is capable of successfully reproducing the interaction between different cellular compartments. As such, our hydrogel co-networks offer a technologically simple yet sophisticated approach to produce functional three-dimensional (3D) in vitro models of epithelial barriers with epithelial and stromal cells arranged in a spatially relevant manner and near-physiological functionality

Modeling Biochemical Gradients In Vitro to Control Cell Compartmentalization in a Microengineered 3D Model of the Intestinal Epithelium

Gradients of signaling pathways within the intestinal stem cell (ISC) niche are instrumental for cellular compartmentalization and tissue function, yet how are they sensed by the epithelium is still not fully understood. Here a new in vitro model of the small intestine based on primary epithelial cells (i), apically accessible (ii), with native tissue mechanical properties and controlled mesh size (iii), 3D villus-like architecture (iv), and precisely controlled biomolecular gradients of the ISC niche (v) is presented. Biochemical gradients are formed through hydrogel-based scaffolds by free diffusion from a source to a sink chamber. To confirm the establishment of spatiotemporally controlled gradients, light-sheet fluorescence microscopy and in-silico modeling are employed. The ISC niche biochemical gradients coming from the stroma and applied along the villus axis lead to the in vivo-like compartmentalization of the proliferative and differentiated cells, while changing the composition and concentration of the biochemical factors affects the cellular organization along the villus axis. This novel 3D in vitro intestinal model derived from organoids recapitulates both the villus-like architecture and the gradients of ISC biochemical factors, thus opening the possibility to study in vitro the nature of such gradients and the resulting cellular response.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH