Bibliografía Botánica Ibérica, 1999 - 2000.

Sin resume

Invisible floral larcenies: microbial communities degrade floral nectar of bumble bee-pollinated plants

8 páginas, 4 figuras, 1 láminaThe ecology of nectarivorous microbial communities remains virtually unknown, which precludes elucidating whether these organisms play some role in plant–pollinator mutualisms beyond minor commensalism. We simultaneously assessed microbial abundance and nectar composition at the individual nectary level in flowers of three southern Spanish bumble bee-pollinated plants (Helleborus foetidus, Aquilegia vulgaris, and Aquilegia pyrenaica cazorlensis). Yeasts were frequent and abundant in nectar of all species, and variation in yeast density was correlated with drastic changes in nectar sugar concentration and composition. Yeast communities built up in nectar from early to late floral stages, at which time all nectaries contained yeasts, often at densities between 104 and 105 cells/mm3. Total sugar concentration and percentage sucrose declined, and percentage fructose increased, with increasing density of yeast cells in nectar. Among-nectary variation in microbial density accounted for 65% (H. foetidus and A. vulgaris) and 35% (A. p. cazorlensis) of intraspecific variance in nectar sugar composition, and 60% (H. foetidus) and 38% (A. vulgaris) of variance in nectar concentration. Our results provide compelling evidence that nectar microbial communities can have detrimental effects on plants and/or pollinators via extensive nectar degradation and also call for a more careful interpretation of nectar traits in the future, if uncontrolled for yeasts.Work was supported by grants 2005-RNM-156 (Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía) and by CGL2006-01355 and EXPLORA CGL2007-28866-E/BOS (Ministerio de Educación y Ciencia, Gobierno de España).Peer reviewe

Determination of Soluble Sugars in Arabidopsis thaliana Leaves by Anion Exchange Chromatography

Determination of soluble sugars is basic for the study of carbon metabolism in plants. Soluble sugar quantitation can be achieved by enzymatic methods implying different coupled reactions. Here we describe a simple method that allows rapid determination of the most abundant soluble sugars (glucose, fructose and sucrose) in Arabidopsis leaves by anion exchange chromatography. We have applied this method to study the levels of soluble sugars during the photoperiodic transition to flowering (Ortiz-Marchena et al., 2014).España, MINECO projects CSD2007-00057, BIO2008-02292, and BIO2011-28847-C02-00España, Junta de Andalucía P06-CVI-01450 and P08-AGR-0358

Experimental Equipment to Develop Teaching of the Concept Viscosity

[EN] Some of the subjects have complex concepts, which are currently taught using deductive methods in the first years of University Degree. However, the experience shows the results obtained from students¿ learning goals were quite low. Therefore, the use of inductive method is a crucial factor to improve students¿ learning results and re-thinking the way to teach in basic subject of Engineering Bachelor Degree. One example is the subject called Fluid Mechanics, which is present in many Bachelor Degrees. This matter has abstract concepts, which are normally taught by traditional methods. This type of teaching makes difficult to be understood by the student. This research proposes an inductive methodology to work the viscosity concept using an activity. In this test, the student has to carry out some measurements with different fluids using a simple measurement device while they participated actively in the learning.Pérez-Sánchez, M.; Galstyan-Sargsyan, R.; Pérez-Sánchez, MI.; López Jiménez, PA. (2018). Experimental Equipment to Develop Teaching of the Concept Viscosity. Education Sciences. 8(4). doi:10.3390/educsci8040179S8

Luminiscence dating of burial 3 and the bell beaker pottery from La Pijotilla (Badajoz, Spain)

La Pijotilla es uno de los mayores asentamientos (80 Ha) del III milenio A.N.E. de la Península Ibérica, siendo considerado un lugar central dentro de la red de poblamiento de Tierra de Barros (comarca de Tierra de Barros, Badajoz). Desde los años 70 se han excavado el poblado y la necrópolis, destacando la tumba T3, excavada en la roca donde se realizaron 300 inhumaciones en capas sucesivas generando una estratigrafía amplia y que contenía un variado y cuantioso ajuar. En el poblado se ha recuperado una colección de fragmentos campaniformes sin contexto estratigráfico, junto a una gran diversidad de estilos decorativos pertenecientes a la última fases del III milenio ANE. El objetivo propuesto en este trabajo ha sido datar diferentes niveles de la tumba T3 y compararlas con otras dataciones C14; al igual que datar la cerámica campaniforme de superficie del poblado y compararla con dataciones absolutas procedentes de contextos habitacionalesLa Pijotilla, one of the largest settlements through out all Iberian Peninsula, and is considered a central place of Tierra de Barros Copper Age settlement network (Comarca de Tierra de Barros, Badajoz). During the field works that has been going on since the 70’s, the settlement and the necropolis area have been located. Several tombs have been excavated, standing out tomb 3, build on the rock with 300 buried individuals and a great richness of funerary objects alternated in several layers. During survey works in the settlement a large amount of decorated pottery from III millennium BC including a great number of Bell Beaker pottery, without a stratigraphic context, have been found. The focus in this work is to date different layers of T3 using luminescence techniques and compare them with old and new radiocarbon dates, as well as to date the survey-collected Bell Beaker pottery and compare them with the settlement radiocarbon datesPlan Nacional de Materiales MAT 2005-000790GRICES-CSIC 2005-PT003