Survey for grapevine yellows phytoplasmas in diverse European countries and Israel

Research NotePhytoplasmas of a large number of GY-affected grapevines from several European countries and Israel were characterized using PCR-RFLP of a 16S rDNA region. Only phytoplasmas in the EY group and the stolbur group were found. The latter was the most wideley spread

Flavescence doree in France and Italy - Occurrence of closely related phytoplasma isolates and their near relationships to Palatinate grapevine yellows and an alder yellows phytoplasma

Grapevine yellows (GY) are diseases of Vitis vinifera caused by phytoplasmas. On the basis of DNA analysis, it is possible to distinguish different groups and subgroups among grapevine phytoplasmas. Flavescence doree (FD), the most serious problem in European vineyards, is caused by a phytoplasma which belongs to the elm yellows group (EY or 16SrV), Differences between 7 phytoplasma isolates in this group, found until now in French, Italian and German grapevines, and 4 phytoplasmas in the same group, isolated mainly from elm and alder in Europe and America, were investigated. These 11 EY-group isolates plus 3 non-EY phytoplasmas, were compared by PCR-RFLP analyses of two different DNA fragments using 8 restriction enzymes. Two French and two Italian grapevine isolates, classified as FD, appeared to be closely related and were also closer to an Italian alder phytoplasma. One French and one Italian FD isolate always showed the same restriction pattern. On the opposite, the three German grapevine isolates related to alder phytoplasmas in Germany appeared to be closer to the two elm phytoplasmas from America and Europe.

Diversity among mycoplasma-like organisms inducing grapevine yellows in France

As antibodies and molecular probes which were previously obtained for diagnosis of grapevine flavescence doree (FD; a yellows disease induced by a MLO), showed to be highly specific, a survey of grapevine samples collected in different viticultural areas in France was undertaken, using a PCR method with primers allowing amplification of a part of the 16S rRNA gene of most MLOs, and restriction analyses of the amplified products (AHRENS and SEEMÜLLER 1992). The presence of MLO was established in all the different grapevine samples, and their diversity was demonstrated. The typcial pattern yielded by FD sensu stricto-MLO was found in samples from southern vineyards, including a symptomless rootstock. Two different patterns were found in samples affected by bois noir disease of northern French vineyards, one of these patterns being previously undescribed. The present survey was non exhaustive and should be followed in the frame of a large collaboration between viticultural countries. It showed the diversity in causal agents of diseases which converge in symptomatology, and emphasizes on the need of specific diagnosis tools, for identification of each of the vector species, for epidemiological studies, and availability of planting material

Repetition and difference: Lefebvre, Le Corbusier and modernity's (im)moral landscape: a commentary

This article engages with the relationship between social theory, architectural theory and material culture. The article is a reply to an article in a previous volume of the journal in question (Smith, M. (2001) ‘Repetition and difference: Lefebvre, Le Corbusier and modernity’s (im)moral landscape’, Ethics, Place and Environment, 4(1), 31-34) and, consequently, is also a direct engagement with another academic's scholarship. It represents a critique of their work as well as a recasting of their ideas, arguing that the matter in question went beyond interpretative issues to a direct critique of another author's scholarship on both Le Corbusier and Lefebvre. A reply to my article from the author of the original article was carried in a later issue of the journal (Smith, M. (2002) ‘Ethical Difference(s): a Response to Maycroft on Le Corbusier and Lefebvre’, Ethics, Place and Environment, 5(3), 260-269)

Detection of flavescence dorée phytoplasma in grapevine in northern Spain

Research NoteGrapevine yellows diseased stocks were observed in vineyards of the Alt Emporda area, northern Spain. Phytoplasma was detected and characterized by PCR-RFLP in the region of the 16S rDNA of phytoplasmas or by ELISA. For the first time a FD phytoplasma was detected in Spain

A multiplex nested-PCR assay for sensitive and simultaneous detection and direct identification of phytoplasma in the Elm yellows group and Stolbur group and its use in survey of grapevine yellows in France

Flavescence dorée and Bois noir (or Vergilbungskrankheit), are two main yellows diseases of grapevines in Europe. The two diseases cannot be distinguished on the basis of symptoms but they are associated with two different phytoplasmas which belong to the Elm yellows (16SrV) group and Stolbur (16SrXII) group, respectively. Their spreading areas are overlapping in France, Italy and Spain but they have different vector insects. Flavescence dorée is an epidemic disease and a quarantine organism. National surveys conducted annually in France require straightforward and sensitive assays to detect phytoplasma that sometimes occur in grapevine with a low titre and to characterize them readily. A bi-specific multiplex nested-PCR procedure was developed, to amplify simultaneously two non-ribosomal DNA fragments, 1150 bp and 720 bp in length, specific for Elm yellows-group and Stolbur-group phytoplasmas, respectively. They were identified using agarose gel electrophoresis of amplification products. The procedure is quick, sensitive and reliable. It was used on 2,525 grapevine samples from the field, in the frame of the French survey in 2002. Mixed samples containing both phytoplasmas displayed a mixed profile in the gel. It was confirmed that the nested-PCR amplimer obtained in the FD9 DNA region with Elm yellows-group phytoplasmas, though shorter than the initial FD9 fragment, nevertheless contained the restriction sites that permit the RFLP identification of geographic phytoplasma isolates already characterized in former studies.

Muons tomography applied to geosciences and volcanology

Imaging the inner part of large geological targets is an important issue in geosciences with various applications. Dif- ferent approaches already exist (e.g. gravimetry, electrical tomography) that give access to a wide range of informations but with identified limitations or drawbacks (e.g. intrinsic ambiguity of the inverse problem, time consuming deployment of sensors over large distances). Here we present an alternative and complementary tomography method based on the measurement of the cosmic muons flux attenuation through the geological structures. We detail the basics of this muon tomography with a special emphasis on the photo-active detectors.Comment: Invited talk at the 6th conference on New Developments In Photodetection (NDIP'11), Lyon-France, July 4-8, 2011; Nuclear Instruments and Methods in Physics Research Section A, 201

Grapevine yellows: Comparison of different procedures for DNA extraction and amplification with PCR for routine diagnosis of phytoplasmas in grapevine

In order to devise a procedure to be used as reference for detection of grapevine phytoplasmas and monitoring of Flavescence dorée, 12 combinations comprising three methods of plant DNA extraction and 4 procedures for amplification in polymerase chain reaction of phytoplasma DNA were examined in parallel using the same plant tissues infected with phytoplasmas. In a first series tissues of periwinkles (Catharanthus roseus) infected with phytoplasma isolates of the Elm yellows group (16SrV) and maintained in the greenhouse, were used. In a second series tissues of grapevines (Vitis vinifera) naturally infected with Flavescence dorée or Palatinate grapevine yellows phytoplasma were used. The DNA preparations obtained with each of the three extraction procedures were used undiluted or serially diluted, as target DNA in the 4 nested-polymerase chain reactions. The results showed differences in the efficiency among different methods of extraction as well as in the sensitivity among the DNA amplification procedures, which improved when DNA extracted from field grapevines was diluted. After additional comparative validation on numerous field-collected samples of GY-affected grapevines, the quickest extraction procedure was selected for use in routine diagnosis, with nested-PCR amplification either of ribosomal DNA or of the FD9 DNA fragment specific for Flavescence dorée and other 16SrV group phytoplasmas

Detección y profilaxis del fitoplasma del amarilleamiento del olmo en Francia

Surveys conducted since 1998, showed that symptoms typical of Elm Yellows (EY) were quite frequent in the elm conservatories of Nogent-sur-Vernisson and Guémené- Penfao, France, and on forest trees in several locations in western Europe. Phytoplasmas were detected in symptomatic trees and plants using Polymerase Chain Reaction amplification followed by Restriction Fragment Length Polymorphism analyses of conserved regions of 16S rDNA of phytoplasmas, or of the EY group-specific non ribosomal DNA fragment FD9. Potential vectors were searched among leafhoppers and planthoppers trapped in conservatories and tested for the presence of phytoplasma in their body. Sanitation of multiplication material was experimented using soaking of dormant cuttings and branches in hot water, according to the method devised for destruction of phytoplasma in grapevine multiplication material. Phytoplasmas detected in a number of the elm clones held in the conservatories and in several forest or hedgerow elm trees, showed some diversity, according to restriction analyses of the FD9 fragment. Both American and European types were characterized. Four leaf- and planthopper species were found to carry an EY phytoplasma. Plants grown from cuttings taken from EY-infected clones and soaked in hot water (50 °C, 45 mn) never developed symptoms and tested phytoplasma negative. Most of untreated control plants were all symptomatic and positive. In the future, EY phytoplasma should be carefully checked, especially in sensitive cultivars. More studies of EY phytoplasma variability and potential vecteurs and the assessment of routine use of hot water therapy in multiplication of material should be conducted.Las observaciones realizadas desde 1998 han mostrado que los síntomas típicos del amarilleamiento del olmo (EY) son muy frecuentes en los bancos de olmo de Nogent- sur-Vernisson y Guémené-Penfao, Francia, y en árboles en campo de varias localidades de Europa occidental. La presencia de fitoplasmas se detectó, mediante el uso de la reacción en cadena de la polimerasa seguida de análisis de polimorfismo de longitud de los fragmentos de restricción en regiones conservadas de rADN de16S de fitoplasmas, o del fragmento FD9 de ADN no ribosómico, específico del fitoplasma del EY, en árboles y plantas sintomáticos. Se buscó vectores potenciales entre homópteros cicadélidos y fulgóridos capturados en los invernáculos y estudiados con el fin de detectar la presencia de fitoplasmas en su cuerpo. Como tratamiento profiláctico del material reproductivo, se experimentó sumergiendo las estaquillas y ramas durmientes en agua caliente, de acuerdo con el método desarrollado para la destrucción de fitoplasmas en material de reproducción de la vid. Según el análisis de restricción del fragmento FD9, los fitoplasmas que fueron detectados en algunos clones de olmo conservados en los bancos clonales, así como en varios olmos de campo, mostraron una cierta diversidad genética. Tanto el tipo americano como el europeo fueron caracterizados. Se encontró que cuatro de las especies de cicadélidos y fulgóridos eran portadoras del fitoplasma del EY. Las plantas que se desarrollaron a partir de estaquillas de clones infectados por el EY y que habían sido sumergidas en agua caliente (50 ºC, 45 minutos) nunca presentaron síntomas. Igualmente, las pruebas para la detección del fitoplasma fueron negativas. Por el contrario, todas las plantas control que no habían sido tratadas presentaron síntomas, y los resultados de las pruebas fueron positivos. En el futuro, la presencia del fitoplasma del EY deberías ser comprobada sistemáticamente, especialmente en cultivares sensibles. Deberían desarrollarse más estudios sobre la variabilidad del fitoplasma del EY y vectores potenciales, y sobre la evaluación del uso continuo del tratamiento con agua caliente en la multiplicación del material