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Deglene-Benbrahim L.,CNRS Vine Biotechnology and Environment Laboratory | Wiedemann-Merdinoglu S.,CNRS Vine Health and Wine Quality | Merdinoglu D.,CNRS Vine Health and Wine Quality | Walter B.,CNRS Vine Biotechnology and Environment Laboratory
American Journal of Enology and Viticulture | Year: 2010

Genetic improvement of grapevine for resistance against downy mildew (Plasmopara viticola) by biotechnological techniques requires reliable procedures to screen large populations of plants. In comparison with greenhouse-grown plants, in vitro plantlets are not often used in screening procedures, although they present some advantages such as compact size, the availability of a high number of replicates per genotype, and the potential to screen improved genotypes directly from in vitro plants. Leaf disc inoculation bioassay was used to evaluate grapevine resistance to downy mildew on Vitis vinifera Chardonnay, hybrid Seyval, and Vitis riparia Gloire de Montpellier (susceptible, moderately susceptible, and highly resistant, respectively) with both in vitro plantlets and greenhouse-grown plants. Disease symptoms and resistance reaction were evaluated for sporula-tion and necrosis in two independent experiments. For all parameters, leaves from in vitro plantlets appeared more resistant than leaves from greenhouse-grown plants, in particular for the intermediate and the susceptible genotypes. Necroses were not observed on leaf discs of the susceptible genotype, whereas necrotic spots appeared on leaf discs of both intermediate and resistant genotypes regardless of how the plants were grown. Based on sporulation and necrosis symptoms, ranking of genotypes differed according to growing conditions. Although the method based on in vitro grown plants is less reliable than that based on greenhouse plants, it can be used as a preliminary assay to eliminate the most susceptible plantlets obtained by biotechnology. © 2010 by the American Society for Enology and Viticulture. All rights reserved.

Kuntzmann P.,Institute Francais Of La Vigne Et Du Vin Ifv | Villaume S.,Conseil Interprofessionnel des Vins dAlsace | Larignon P.,Institute Francais Of La Vigne Et Du Vin Ifv | Bertsch C.,CNRS Vine Biotechnology and Environment Laboratory
Vitis - Journal of Grapevine Research | Year: 2010

The French vineyard is affected by three principal wood diseases: Eutypa dieback, esca and black dead arm (BDA). Phaeomoniella chlamydospora, Phaeocremonium aleophilum, Eutypa lata, Fomitiporia mediterranea, Diplodia seriata, Diplodia mutila and Neofusicoccum parvum are the main fungi isolated in France and associated with grapevine trunk diseases. The aim of this study was to highlight the type of wood lesions and the fungus present in the Alsace vineyards (France) and to compare it with those identified in the other french vine-growing regions or with the German vineyards. Therefore, we have studied two vineyards with two different grapevine varieties ('Auxerrois', 'Gewürztraminer'). The foliar symptoms showed that the plots planted with 'Auxerrois' and 'Gewürztraminer' varieties had respectively 12 and 21 % grapevines with symptoms in 2005. Different cross sections were made on trunks and arms of 55 vines showing foliar symptoms, totalizing 162 microbiological isolations. Visual characterisations of the different lesions were described. The isolations made from the different necrosis showed the presence of species of fungi involved in grapevine trunk diseases and other fungi. Microbiological observations showed that for the Auxerrois vineyard the majority of the vines were infected with D. seriata, P. chlamydospora, E. lata and F. mediterranea. In the Gewürztraminer vineyard, the fungus most frequently isolated was P. chlamydospora, followed by D. seriata. The presence of D. seriata in different parts of the grapevine wood and in young wood is related to the severe damages observed on the vegetation.

Cornu J.Y.,French National Institute for Agricultural Research | Cornu J.Y.,CNRS Vine Biotechnology and Environment Laboratory | Schneider A.,French National Institute for Agricultural Research | Jezequel K.,CNRS Vine Biotechnology and Environment Laboratory | Denaix L.,French National Institute for Agricultural Research
Geoderma | Year: 2011

It is well established that the soil temperature impacts on the mobility of Cd in soil but the role of dissolved organic matter (DOM) quality in this process is still unclear. During a 42-day period, soil solutions were sampled from a Cd-contaminated soil incubated at 10, 20 or 30°C. The quantity and the quality of DOM were monitored over time as well as the concentration and the speciation of dissolved Cd. The fraction of Cd complexed by ligands (f CdL) increased over time and with the rise in soil temperature and exhibited a significant correlation with the absorbance of DOM at 254nm. In contrast, the quantity of DOM did not much vary between soil solutions. These results suggest that, during incubation, the composition of DOM shifted to more aromatic compounds, assimilated to humic substances (HS), with higher Cd affinity. The kinetics of DOM aromatization and Cd complexation were described using thermal time. A first order model adequately fitted all the experimental data, suggesting that similar microbial processes responsible for the aromatization of DOM occurred at 10, 20 and 30°C. The fraction of Cd complexed by ligands was predicted by Visual MINTEQ using the solution properties measured at 140day-degrees and the specific UV-absorbance of DOM (SUVA) monitored over thermal time. SUVA values were used to adjust the reactivity ratio of DOM (R). The model predictions were highly correlated with the measured values but they overestimated f CdL. It is concluded that the aromaticity of DOM should be taken into account to predict the impact of soil temperature on the complexation of Cd in rewetted soils. The relation between SUVA values and the HS fraction of DOM still needs, however, to be worked out. © 2011 Elsevier B.V.

Bertsch C.,CNRS Vine Biotechnology and Environment Laboratory | Ramirez-Suero M.,CNRS Vine Biotechnology and Environment Laboratory | Magnin-Robert M.,CNRS Research Unit on Grapevine and Wines in Champagne | Larignon P.,Institute Francais Of La Vigne Et Du | And 5 more authors.
Plant Pathology | Year: 2013

This review presents an overview of eutypa dieback, esca and botryosphaeria dieback, the predominant grapevine trunk diseases worldwide. It covers their symptomatologies in the trunk, leaves and berries; the characteristics of the different fungal species associated with them; and host-pathogen interactions. Here, the host-pathogen relationship is defined at the cytological, physiological and molecular levels. Currently available experimental tools for studying these diseases, both in vitro and in the field, are discussed. Finally, a progress report on their control, which, since the ban of sodium arsenite, comprises chemical, biological and/or sanitation methods, is presented. © 2012 The Authors. Plant Pathology © 2012 BSPP.

Szakiel A.,University of Warsaw | Paczkowski C.,University of Warsaw | Pensec F.,CNRS Vine Biotechnology and Environment Laboratory | Bertsch C.,CNRS Vine Biotechnology and Environment Laboratory
Phytochemistry Reviews | Year: 2012

The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed. © 2012 The Author(s).

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