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

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

OBTENTION OF SPECIFIC MONOCLONAL ANTIBODIES AND ANTISERA AGAINST XYLELLA FASTIDIOSA AND THEIR USE FOR DETECTION AND DIAGNOSIS

Monoclonal antibodies (MAb) specific to Xylella fastidiosa were obtained by fusion of a nonsecreting myeloma cell line with spleen cells from immunized BALB/c mice by intraperitoneal injections of 0.1 ml of 108 cfu/ml of X. fastidiosa subsp. fastidiosa (LMG17159 strain) (somatic antigens O) emulsified in Freund’s incomplete adjuvant. Specific antibody-secreting hybridoma selected by indirect-ELISA was three times cloned under conditions of limiting dilution and established hybrids were grown in HT medium. Ten MAb lines producing the highest bacterial titre were selected, isotype determined and their specificity tested. Three MAbs (MAb2G1/PPD, MAb1C6/PPD and MAb9F7/PPD) were selected for their wide reaction spectrum against X. fastidiosa strains and good specificity. Furthermore six polyclonal antisera against X. fastidiosa were raised in CalifornianxNeozelander rabbits with O antigens from Conn Creek, LMG15099 and LMG17159 strains. LMG17159-O antiserum was selected for the higher titre and because it recognized all the X. fastidiosa strains challenged. Polyclonal immunoglobulins as trapping/coating antibodies and specific MAb2G1/PPD as intermediate-detecting antibodies (DASI-ELISA method) reached a sensitivity of 105 cfu/ml of Xylella fastidiosa in almond extracts and of 105-106 in olive extracts. A DAS-ELISA prototype was then developed, prior to commercial distribution, using MAb2G1/PPD conjugated with alkaline phosphatase. The sensitivity reached was 105 cfu/ml and showed excellent specificity. One hundred twelve samples of different almond tree plots from the Demarcated Zone for X. fastidiosa in Alicante (Spain) were analysed comparatively by the developed DAS-ELISA, the LOEWE kit and the protocols of real-time PCR by Harper et al. (2010) and Francis et al. (2006). The agreement between the techniques was almost perfect according to the estimated Cohen’s kappa index, even in symptomless almond trees. The production of specific MAbs to X. fastidiosa will supply a continuous source of homogenous and well characterized antibodies to increase the accuracy of diagnosis and detection methods. A direct tissue-print or DTBIA kit is being also validated in order to supply an available user-friendly system to test in a low cost, fast, discreet, sensitive, an accurate manner this harmful bacterium in samples from nurseries, gardens and wide surveys, such as is available for other plant pathogens