Estudios biosistemáticos en Pteridófitos europeos

Desde el trabajo de Irene Manton (1950) Problems ofCylology andEvolUliOll in the Pteridophyta, gran parte de la investigación en helechos ha estado fuertemente influída por el enfoque biosistemático de esta autora. Algunos ejemplos pueden poner de manifiesto el estado actual de los conocimientos y los problemas que aún quedan por resolver: I) Se han establecido las relaciones genéticas existentes entre las tres especies ampliamente distribuídas en Europa de Polypodium (P. cambricum, P. vulgare y P. illlerjectum), y el origen de sus tres híbridos silvestres. Sin embargo, aún están sin aclarar las relaciones que existen entreP. cambricum y las poblaciones diploides de Macaronesia (P. azoricum y P. macaronesicumï. IT) La taxonomía del género Cheilamhes en Europa y Macaronesia se ha esclarecido gracias al estudio de numerosos híbridos, tanto silvestres como producidos en laboratorio. A pesar de ello, sería conveniente confirmar la naturaleza alopoliploide de C. tinaei, mediante lasíntesis de un híbrido amplio (i.e. unhíbrido entre C. tinaei y undiploide o tetraploide no relacionado). III) Aunque se han realizado numerosos trabajos sobre Cystopterisfragilis aggr.,las relaciones genéticas dentro de este complejo permanecen oscuras y la taxonomía está lejos de estar resuelta. IV)Aspleniumes uno de los géneros mejorconocidos y más estudiados de Ewopa. No obstante, quedan aspectos por resolver, en particular los relacionados con el complejo A. trichomanes, en el cual la autopoliploidía y la diversificación ecológica han generado táxones poco diferenciados en su morfología y genética.Since the book of Irene Manton (1950) Problems ofCytology and Evolution in the Pteridophyta, and greatly influenced by her biosystematic approach, much work has been done on ferns in Europe. Some examples can help to clarify how far are we now from these early days, and what remains to be done regarding the European ferns under a biosystematic point of view: I) The genetic relationships between the three widespread species ofPolypodium in Europe (P. cambricum, P. vulgare and P. illlerjectum) and the origin of their three wild hybrids have been stablished. Nevertheless, experimental work is still needed to clarify the relationship between P. cambricum and diploids populations from Macaronesia (P. azoricum and P. macaronesicumy. IT) Based on the study of both, wild and synthesized hybrids. the taxonomy of the genus Cheilanthes of Europe and Macaronesia has been almost completely disentangled. III) Even if much work on the biosystematics of Cystopteris fragilis aggr. has been done, the genetic relationships within the complex and its taxonomy are still an unsettled matter. Several levels of ploidy (from 4x to 8x) have been found in European plants, however, the diploids ancestors are still missing. This adds difficulties to the experimental work needed to cope with this troublesome group. IV) Asplenium is one of the most studied and best known genus of Europe. Nevertheless, some aspects remain unsufficiently known, in particular those related to theA. trichomanes complex, in which. autopoliploidy together with ecological diversification have resulted in taxa poorly differentiated regarding morphology and genetics

Estudio taxonómico de los genéros Ulex L. y Stauracanthus link. en la Península Ibérica

Tesis Univ. Complutense de Madrid.Fac. de Ciencias BiológicasTRUEProQuestpu

Técnicas y métodos para la iniciación en el estudio de la evolución molecular con aplicaciones especiales para el análisis de los hongos liquenizados.

Sin resume

Origin and Diversification of Major Clades in Parmelioid Lichens (Parmeliaceae, Ascomycota) during the Paleogene Inferred by Bayesian Analysis

There is a long-standing debate on the extent of vicariance and long-distance dispersal events to explain the current distribution of organisms, especially in those with small diaspores potentially prone to long-distance dispersal. Age estimates of clades play a crucial role in evaluating the impact of these processes. The aim of this study is to understand the evolutionary history of the largest clade of macrolichens, the parmelioid lichens (Parmeliaceae, Lecanoromycetes, Ascomycota) by dating the origin of the group and its major lineages. They have a worldwide distribution with centers of distribution in the Neo- and Paleotropics, and semi-arid subtropical regions of the Southern Hemisphere. Phylogenetic analyses were performed using DNA sequences of nuLSU and mtSSU rDNA, and the protein-coding RPB1 gene. The three DNA regions had different evolutionary rates: RPB1 gave a rate two to four times higher than nuLSU and mtSSU. Divergence times of the major clades were estimated with partitioned BEAST analyses allowing different rates for each DNA region and using a relaxed clock model. Three calibrations points were used to date the tree: an inferred age at the stem of Lecanoromycetes, and two dated fossils: Parmelia in the parmelioid group, and Alectoria. Palaeoclimatic conditions and the palaeogeological area cladogram were compared to the dated phylogeny of parmelioid. The parmelioid group diversified around the K/T boundary, and the major clades diverged during the Eocene and Oligocene. The radiation of the genera occurred through globally changing climatic condition of the early Oligocene, Miocene and early Pliocene. The estimated divergence times are consistent with long-distance dispersal events being the major factor to explain the biogeographical distribution patterns of Southern Hemisphere parmelioids, especially for Africa-Australia disjunctions, because the sequential break-up of Gondwana started much earlier than the origin of these clades. However, our data cannot reject vicariance to explain South America-Australia disjunctions

A descriptive and quantitative approach regarding erosion and development of landforms on abandoned mine tailings: New insights and environmental implications from SE Spain

The San Cristóbal–Perules mining site in Mazarrón in southeast Spain was subjected to about a hundred years of intense mining activity for lead, silver, and zinc. Metallurgical operations (smelting, calcination, gravity concentration) carried out during the late nineteenth century–early twentieth century induced significant land transformation, and the most conspicuous wastes of this period consist of a chaotic piling of ‘old’ tailing deposits. Later on, during the mid-twentieth century, ‘modern’ tailings resulting from froth flotation were accumulated filling small valleys; these latter valley-fill tailings rose sequentially according to the upstream construction method, progressively raising the level of the dam during the process. Once abandoned, both types of tailing deposits underwent severe erosion, resulting in a mosaic of erosional and sedimentary landforms developed upon (e.g., gully formation) and within them (e.g., piping). We made an inventory and classification of these landforms. Our study shows the geomorphic work to reestablish a new steady state between the tailings deposits and the local erosive conditions. This scenario implies several hazards related to the extremely high heavy metal contents of these tailings and the geomorphic instability of the deposits. We also quantified the tailings tonnage and erosion that occurred at one of the tailings dams (El Roble). As shown by an oblique aerial photograph taken in 1968, this dam had a terraced topography, whereas in 2013 this morphology had evolved into a badland-type relief with deep parallel gullies. By recognizing and surveying specific, remnant points along the benches and outslopes of the older terraced topography, we were able to build up a first digital elevation model (DEM1) reflecting the initial topography. A second DEM, this time showing the present topography, allowed quantification of erosion via Material Loss = DEM1 − DEM2. This yields an erosion rate (1968–2009) of 151.8 Mg (MT) ha− 1 y− 1, which matches well typical values for erosion of mined areas, commonly above 100 Mg (MT) ha− 1 y− 1. Abandoned mine tailing deposits are extremely common in the semiarid scenarios of the SW USA, Australia, Chile, and Peru. Given the similarities of these scenarios with SE Spain, the example from Mazarrón may provide useful new insights regarding the erosion and geomorphic evolution of such tailing deposits. These matters should be addressed in key environmental actions such as mine closure plans and land reclamation projects. A solution may come via restoration of these deposits through landform design involving the building up of stable mature landscapes, which in turn can withstand erosion much more easily.Peer reviewe

Effect of pH Variation on Synthesis and Photocatalytic Activity of Bi2Fe4O9

The Pechini synthesis method, presents chemical homogeneity as its main advantage, enabling the desired phase to be obtained. This synthesis usually occurs at pH 7. In this study, Bi2Fe4O9 was synthesized using the Pechini method at different pHs (pH= 3, 5, 7, 8, 10 and 12) to verify if the pH conditions can influence in its photocatalytic activity. The materials obtained at different conditions were characterized by using X rays diffraction (XRD), UV/Vis diffuse reflectance and scanning electron microscopy by field emission (MEV/FEG).It was possible to synthesize the material under conditions already mentioned, but it was not observed significant differences in the chemical structure of the obtained materials from the characterization techniques. However, they presented a small variation in the band gap values, morphological aspects and photocatalytic activities. All the materials proved to be a good semiconductor, maintaining high degradation rates. The photocatalyst synthesized at pH 3 (BFO - 1) presented a degradation rate of approximately 95% for the group chromophore and 93% for the aromatic group of the structure of the tartrazine yellow dye, proving to be a promising photocatalyst for industrial applications. This result is particularly important because BFO – 1 showed higher catalyst activity since the chromophore of the aromatic group was degraded. The highlights of this study is the synthesis of Bi2Fe4O9 performed at pH=3, since it reduces the quantity of reagents comparing to the conventional Pechini method and presented high photocatalytic activity. DOI: http://dx.doi.org/10.17807/orbital.v13i2.148

Ulex parviflorus sensu lato (Genisteae, Leguminosae) en la zona centro de Portugal

A group of gorses growing in Central Portugal has been traditionally identified as Ulex parviflorus Pourret sensu lato. The study of these plants reveáls important differences in morphological characters such as size, ramification, colour and indumentum of shoots, the type, disposition and indumentum of primary and secondary spines, and the dimensions, shape and indumentum of the calyx. Based on these morphological characteristics, as well as chromosome number, ecological requirements and geographic distribution, the plants are now ascribed to the following taxa: U. airensis sp. nov., U. australis subsp. welwitschianus stat. & comb. nov., U. eriocladus C. Vicioso and U. jussiaei WebbEn la zona centro de Portugal crece un conjunto de tojos que han sido tradicionalmente identificados como Ulex parviflorus Pourret sensu lato. Sin embargo, estas plantas presentan diferencias morfológicas en el porte, ramificación, color e indumento de ejes y ramas, en el tipo, disposición e indumento de las espinas primarias y secundarias y en las dimensiones, forma e indumento del cáliz. Estos caracteres morfológicos, el número cromosómico, los requerimientos ecológicos y el área geográfica permiten adscribir estas plantas a los siguientes táxones: U. airensis sp. nov., U. australis subsp. welwitschianus stat. & comb. nov., U. eriocladus C. Vicioso y U. jussiaei Webb

Caracterización del yacimiento de Cueva Blanca (Hellín, Albacete). Nuevas aportaciones para el debate en torno a la transición del Mesolítico al Neolítico antiguo en el Sureste peninsular

The site of Cueva Blanca was discovered in 2006 and its excavations yielded an archaeological level ascribed to thetransitional period between the Mesolithic and the Early Neolithic. In this paper we present the results derived from thedifferent analyses applied to the archaeological and biological materials. In addition, we have examined the archaeologicalsites showing more similarities with Cueva Blanca in its regional context. Its geographical situation, between theMediterranean coast and the inner Meseta, together with the existence of prehistoric rock art evidence confers a highrelevance and exceptionality to this site.El yacimiento de Cueva Blanca (Hellín, Albacete), descubierto en el año 2006, posee un nivel arqueológico que hemosatribuido al periodo transicional entre el Mesolítico y el Neolítico antiguo. En este trabajo se presentan los resultadosde los análisis llevados a cabo con los diferentes materiales arqueológicos y biológicos hallados, al tiempo que se definela secuencia estratigráfica. Se examinan también los yacimientos que muestran más semejanzas con el Abrigo de CuevaBlanca dentro de su contexto regional. La situación geográfica del emplazamiento, a caballo entre la costa mediterráneay el interior peninsular, junto con la existencia de paneles de arte rupestre prehistórico confiere a este yacimientouna indudable relevancia y una cierta excepcionalidad