Els Mixomicets recol·lectats en àrees de baixa altitud dins del programa «Biodiversitat dels fongs de Catalunya»

Els Mixomicets recol•lectats en àrees de baixa altitud dins del programa "Biodiversitat dels Fongs de Catalunya". Aquest treball aplega les dades referents a les recol·leccions de mixomicets fetes a Catalunya, en localitats de baixa altitud (la majoria entre 10 i 500 ms.m.), sobretot en àrees poc plujoses situades a les comarques occidentals, meridionals o costaneres. Són notables les recol·lecions fetes a les comunitats dominades per Cistus monspeliensis, on destaquen fisarals com Badhamia foliicola, Didymium eximium, D. melanospermum, D. squamulosum, Leocarpus fragilis, Physarum bitectum i P. cinereum. En altres hàbitats destaquen les troballes d' Arcyria affinis, Badhamia utricularis, Comatricha alta, C. ellae, Didymium eximium. Physarum melleum i P. pezizoideum.The Myxomycetes collected on lowland areas under the research program "Fungal Biodiversity ofthe Catalonia". Thi s paper summarizes the data on Myxomycetes found in Catalonia, in lowland localities (most from 10 to 500 m), preferentially in areas of low pluvios ity from the western, southern and coastal areas. Especially relevant are the collections made under Cistus monspeliensis, with occasional blooms of Physarales, such as: Badhamia foliicola, Didymium eximium, D. melanospermum, D. squamulosum, Leocarpus fragilis, Physarum bitectum and P. cinereum. In other habit ats, some taxa are of special interest: Arcyria affinis, Badhamia utricularis, Comatricha alta, C. ellae, Didymium eximium. Physarum melleum and P. pezizoideum

Els Mixomicets recol·lectats en àrees de baixa altitud dins del programa «Biodiversitat dels fongs de Catalunya»

Els Mixomicets recollectats en àrees de baixa altitud dins del programa "Biodiversitat dels Fongs de Catalunya". Aquest treball aplega les dades referents a les recol·leccions de mixomicets fetes a Catalunya, en localitats de baixa altitud (la majoria entre 10 i 500 ms.m.), sobretot en àrees poc plujoses situades a les comarques occidentals, meridionals o costaneres. Són notables les recol·lecions fetes a les comunitats dominades per Cistus monspeliensis, on destaquen fisarals com Badhamia foliicola, Didymium eximium, D. melanospermum, D. squamulosum, Leocarpus fragilis, Physarum bitectum i P. cinereum. En altres hàbitats destaquen les troballes d' Arcyria affinis, Badhamia utricularis, Comatricha alta, C. ellae, Didymium eximium. Physarum melleum i P. pezizoideum.The Myxomycetes collected on lowland areas under the research program "Fungal Biodiversity ofthe Catalonia". Thi s paper summarizes the data on Myxomycetes found in Catalonia, in lowland localities (most from 10 to 500 m), preferentially in areas of low pluvios ity from the western, southern and coastal areas. Especially relevant are the collections made under Cistus monspeliensis, with occasional blooms of Physarales, such as: Badhamia foliicola, Didymium eximium, D. melanospermum, D. squamulosum, Leocarpus fragilis, Physarum bitectum and P. cinereum. In other habit ats, some taxa are of special interest: Arcyria affinis, Badhamia utricularis, Comatricha alta, C. ellae, Didymium eximium. Physarum melleum and P. pezizoideum

Selective Reflection Spectroscopy on the UV Third Resonance Line of Cs : Simultaneous Probing of a van der Waals Atom-Surface Interaction Sensitive to Far IR Couplings and of Interatomic Collisions

We report on the analysis of FM selective reflection experiments on the 6S1/2->8P3/2 transition of Cs at 388 nm, and on the measurement of the surface van der Waals interaction exerted by a sapphire interface on Cs(8P3/2). Various improvements in the systematic fitting of the experiments have permitted to supersede the major difficulty of a severe overlap of the hyperfine components, originating on the one hand in a relatively small natural structure, and on the other hand on a large pressure broadening imposed by the high atomic density needed for the observation of selective reflection on a weak transition. The strength of the van der Waals surface interaction is evaluated to be 73$\pm$10 kHz.$\mu$m3. An evaluation of the pressure shift of the transition is also provided as a by-product of the measurement. We finally discuss the significance of an apparent disagreement between the experimental measurement of the surface interaction, and the theoretical value calculated for an electromagnetic vacuum at a null temperature. The possible influence of the thermal excitation of the surface is evoked, because, the dominant contributions to the vW interaction for Cs(8P3/2) lie in the far infrared range.Comment: submitted to Laser Physics - issue in the memory of Herbert Walther

Innovative tools for detection of plant pathogenic viruses and bacteria

Detection of harmful viruses and bacteria in plant material, vectors or natural reservoirs is essential to ensure safe and sustainable agriculture. The techniques available have evolved significantly in the last few years to achieve rapid and reliable detection of pathogens, extraction of the target from the sample being important for optimising detection. For viruses, sample preparation has been simplified by imprinting or squashing plant material or insect vectors onto membranes. To improve the sensitivity of techniques for bacterial detection, a prior enrichment step in liquid or solid medium is advised. Serological and molecular techniques are currently the most appropriate when high numbers of samples need to be analysed. Specific monoclonal and/or recombinant antibodies are available for many plant pathogens and have contributed to the specificity of serological detection. Molecular detection can be optimised through the automatic purification of nucleic acids from pathogens by columns or robotics. New variants of PCR, such as simple or multiplex nested PCR in a single closed tube, co-operative- PCR and real-time monitoring of amplicons or quantitative PCR, allow high sensitivity in the detection of one or several pathogens in a single assay. The latest development in the analysis of nucleic acids is microarray technology, but it requires generic DNA/RNA extraction and pre-amplification methods to increase detection sensitivity. The advances in research that will result from the sequencing of many plant pathogen genomes, especially now in the era of proteomics, represent a new source of information for the future development of sensitive and specific detection techniques for these microorganisms

Genetic diversity reflects geographical origin of Ralstonia solanacearum strains isolated from plant and water sources in Spain

The characterization and intraspecific diversity of a collection of 45 Ralstonia solanacearum strains isolated in Spain from different sources and geographical origins is reported. To test the influence of the site and the host on strain diversity, phenotypic and genotypic analysis were performed by a polyphasic approach. Biochemical and metabolic profiles were compared. Serological relationship was evaluated by Indirect-ELISA using polyclonal and monoclonal antibodies. For genotypic analysis, hrpB and egl DNA sequence analysis, repetitive sequences (rep-PCR), amplified fragment length polymorphism (AFLP) profiles and macrorestriction with XbaI followed by pulsed field gel electrophoresis (PFGE) were performed.The biochemical and metabolic characterization, serological tests, rep-PCR typing and phylogenetic analysis showed that all analysed strains belonged to phylotype II sequevar 1 and shared homogeneous profiles. However, interesting differences among strains were found by AFLP and macrorestriction with XbaI followed by PFGE techniques, some profiles being related to the geographical origin of the strains. Diversity results obtained offer new insights into the biogeography of this quarantine organism and its possible sources and reservoirs in Spain and Mediterranean countries.Keywords: Bacterial wilt · potato · soil · PFGE · AFL